[Git][ghc/ghc][wip/T16806] 550 commits: Factor out HsSCC/HsCoreAnn/HsTickPragma into HsPragE

Simon Jakobi gitlab at gitlab.haskell.org
Mon Mar 30 19:48:41 UTC 2020



Simon Jakobi pushed to branch wip/T16806 at Glasgow Haskell Compiler / GHC


Commits:
6985e0fc by Vladislav Zavialov at 2019-11-28T15:47:53+03:00
Factor out HsSCC/HsCoreAnn/HsTickPragma into HsPragE

This is a refactoring with no user-visible changes (except for GHC API
users). Consider the HsExpr constructors that correspond to user-written
pragmas:

  HsSCC         representing  {-# SCC ... #-}
  HsCoreAnn     representing  {-# CORE ... #-}
  HsTickPragma  representing  {-# GENERATED ... #-}

We can factor them out into a separate datatype, HsPragE. It makes the
code a bit tidier, especially in the parser.

Before this patch:

  hpc_annot :: { Located ( (([AddAnn],SourceText),(StringLiteral,(Int,Int),(Int,Int))),
                           ((SourceText,SourceText),(SourceText,SourceText))
                         ) }

After this patch:

  prag_hpc :: { Located ([AddAnn], HsPragE GhcPs) }

- - - - -
7f695a20 by Ömer Sinan Ağacan at 2019-11-29T08:25:28-05:00
Pass ModDetails with (partial) ModIface in HscStatus

(Partial) ModIface and ModDetails are generated at the same time, but
they're passed differently: ModIface is passed in HscStatus consturctors
while ModDetails is returned in a tuple. This refactors ModDetails
passing so that it's passed around with ModIface in HscStatus
constructors. This makes the code more consistent and hopefully easier
to understand: ModIface and ModDetails are really very closely related.
It makes sense to treat them the same way.

- - - - -
e921c90f by Ömer Sinan Ağacan at 2019-11-29T08:26:07-05:00
Improve few Foreign.Marshal.Utils docs

In copyBytes and moveBytes mention which argument is source and which is
destination.

Also fixes some of the crazy indentation in the module and cleans
trailing whitespace.

- - - - -
316f2431 by Sebastian Graf at 2019-11-30T02:57:58-05:00
Hadrian docs: Rename the second "validate" entry to "slow-validate" [ci skip]

That would be in line with the implementation.

- - - - -
5aba5d32 by Vladislav Zavialov at 2019-11-30T02:58:34-05:00
Remove HasSrcSpan (#17494)

Metric Decrease:
    haddock.compiler

- - - - -
d1de5c22 by Sylvain Henry at 2019-11-30T02:59:13-05:00
Use Hadrian by default in validate script (#17527)

- - - - -
3a96a0b6 by Sebastian Graf at 2019-11-30T02:59:55-05:00
Simpler Semigroup instance for InsideLam and InterestingCtxt

This mirrors the definition of `(&&)` and `(||)` now, relieving the
Simplifier of a marginal amount of pressure.

- - - - -
f8cfe81a by Roland Senn at 2019-11-30T20:33:49+01:00
Improve tests for #17171

While backporting MR !1806 to 8.8.2 (!1885) I learnt the following:

* Tests with `expect_fail` do not compare `*.stderr` output files. So a test using `expect_fail` will not detect future regressions on the `stderr` output.
* To compare the `*.stderr` output files, I have to use the `exit_code(n)` function.
* When a release is made, tests with `makefile_test` are converted to use `run_command`.
* For the test `T17171a` the return code is `1` when running `makefile_test`, however it's `2` when running `run_command`.

Therefore I decided:

* To improve my tests for #17171
* To change test T17171a from `expect_fail` to `exit_code(2)`
* To change both tests from  `makefile_test` to `run_command`

- - - - -
2b113fc9 by Vladislav Zavialov at 2019-12-01T08:17:05-05:00
Update DisambECP-related comments

- - - - -
beed7c3e by Ben Gamari at 2019-12-02T03:41:37-05:00
testsuite: Fix location of typing_stubs module

This should fix the build on Debian 8.

- - - - -
53251413 by Ben Gamari at 2019-12-02T03:42:14-05:00
testsuite: Don't override LD_LIBRARY_PATH, only prepend

NixOS development environments often require that LD_LIBRARY_PATH
be set in order to find system libraries. T1407 was overriding
LD_LIBRARY_PATH, dropping these directories. Now it merely prepends,
its directory.
- - - - -
65400314 by Krzysztof Gogolewski at 2019-12-02T03:42:57-05:00
Convert warnings into assertions

Since the invariants always hold in the testsuite, we can convert
them to asserts.

- - - - -
18baed64 by Alan Zimmerman at 2019-12-02T03:43:37-05:00
API Annotations: Unicode '->' on HsForallTy

The code fragment

  type family Proxy2' ∷ ∀ k → k → Type where
    Proxy2' = Proxy'

Generates AnnRarrow instead of AnnRarrowU for the first →.

Fixes #17519

- - - - -
717f3236 by Brian Wignall at 2019-12-02T03:44:16-05:00
Fix more typos

- - - - -
bde48f8e by Ben Gamari at 2019-12-02T11:55:34-05:00
More Haddock syntax in GHC.Hs.Utils

As suggested by RyanGlScott in !2163.

- - - - -
038bedbc by Ben Gamari at 2019-12-02T11:56:18-05:00
Simplify: Fix pretty-printing of strictness

A colleague recently hit the panic in Simplify.addEvals and I noticed
that the message is quite unreadable due to incorrect pretty-printing.
Fix this.

- - - - -
c500f652 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Fix changelog linting logic

- - - - -
8ead967d by Ben Gamari at 2019-12-02T11:56:54-05:00
win32-init: Drop workaround for #17480

The `process` changes have now been merged into `hsc2hs`.

(cherry picked from commit fa029f53132ad59f847ed012d3b835452cf16615)

- - - - -
d402209a by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Disable Sphinx build on Debian 8

The docutils version available appears to be too old to support the
`table` directive's `:widths:` options.

(cherry picked from commit 75764487a96a7a026948b5af5022781872d12baa)

- - - - -
f1f68824 by Ben Gamari at 2019-12-02T11:56:54-05:00
base: Fix <unistd.h> #include

Previously we were including <sys/unistd.h> which is available on glibc
but not musl.

(cherry picked from commit e44b695ca7cb5f3f99eecfba05c9672c6a22205e)

- - - - -
37eb94b3 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Bump Docker images

Installs pxz on Centos7

(cherry picked from commit 86960e691f7a600be247c32a7cf795bf9abf7cc4)

- - - - -
aec98a79 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: pxz is unavailable on CentOS 7

Fall back to xz

- - - - -
6708b8e5 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Set LANG on CentOS 7

It otherwise seems to default to ascii

- - - - -
470ef0e7 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Consolidate release build configuration

- - - - -
38338757 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Add Debian 10 builds

- - - - -
012f13b5 by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Fix Windows bindist collection

Apparently variable interpolation in the `artifacts.paths` key of
`gitlab-ci.yml` doesn't work on Windows as it does on WIndows.

(cherry picked from commit 100cc756faa4468ed6950116bae30609c1c3468b)

- - - - -
a0f09e23 by Ben Gamari at 2019-12-02T11:56:54-05:00
testsuite: Simplify Python <3.5 fallback for TextIO

(cherry picked from commit d092d8598694c23bc07cdcc504dff52fa5f33be1)

- - - - -
2b2370ec by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Add release-x86_64-linux-deb9 job

(cherry picked from commit cbedb3c4a90649f474cb716842ba53afc5a642ca)

- - - - -
b1c206fd by Ben Gamari at 2019-12-02T11:56:54-05:00
gitlab-ci: Always build source tarball

(cherry picked from commit 67b5de88ef923971f1980335137e3c7193213abd)

- - - - -
4cbd5b47 by Sergei Trofimovich at 2019-12-02T11:57:33-05:00
configure.ac: make cross-compiler detection stricter

Be more precise at detecting cross-compilation case.

Before the change configuration
  $ ./configure --host=x86_64-pc-linux-gnu --target=x86_64-gentoo-linux-musl
was not considered a cross-target. Even though libcs are different (`glibc` vs. `musl`).

Without this patch build fails as:

```
"inplace/bin/ghc-cabal" check libraries/integer-gmp
"inplace/bin/ghc-cabal" configure libraries/integer-gmp dist-install \
    --with-ghc="/home/slyfox/dev/git/ghc/inplace/bin/ghc-stage1" \
    --with-ghc-pkg="/home/slyfox/dev/git/ghc/inplace/bin/ghc-pkg" \
    --disable-library-for-ghci --enable-library-vanilla --enable-library-for-ghci \
    --enable-library-profiling --enable-shared --with-hscolour="/usr/bin/HsColour" \
    --configure-option=CFLAGS="-Wall \
    -Werror=unused-but-set-variable -Wno-error=inline \
    -iquote /home/slyfox/dev/git/ghc/libraries/integer-gmp" \
    --configure-option=LDFLAGS="  " --configure-option=CPPFLAGS="   \
    " --gcc-options="-Wall     -Werror=unused-but-set-variable -Wno-error=inline -iquote /home/slyfox/dev/git/ghc/libraries/integer-gmp   \
    " --with-gcc="x86_64-gentoo-linux-musl-gcc" --with-ld="x86_64-gentoo-linux-musl-ld.gold" --with-ar="x86_64-gentoo-linux-musl-ar" \
    --with-alex="/usr/bin/alex" --with-happy="/usr/bin/happy"
Configuring integer-gmp-1.0.2.0...
configure: WARNING: unrecognized options: --with-compiler
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking for gcc... /usr/lib/ccache/bin/x86_64-gentoo-linux-musl-gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... configure: error: in `/home/slyfox/dev/git/ghc/libraries/integer-gmp/dist-install/build':
configure: error: cannot run C compiled programs.
If you meant to cross compile, use `--host'.
See `config.log' for more details
make[1]: *** [libraries/integer-gmp/ghc.mk:5: libraries/integer-gmp/dist-install/package-data.mk] Error 1
make: *** [Makefile:126: all] Error 2
```

Note: here `ghc-stage1` is assumed to target `musl` target but is passed
`glibc` toolchain. It happens because initial ./configure phase did not
detect host/target as different.

Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>

- - - - -
5f7cb423 by Sylvain Henry at 2019-12-02T23:59:29-05:00
Add `timesInt2#` primop

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fbbe18a2 by Sylvain Henry at 2019-12-02T23:59:29-05:00
Use the new timesInt2# primop in integer-gmp (#9431)

- - - - -
5a4b8d0c by Athas at 2019-12-03T00:00:09-05:00
Document RTS behaviour upon encountering '--'.
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705a16df by Ben Gamari at 2019-12-03T07:11:33-05:00
Make BCO# lifted

In #17424 Simon PJ noted that there is a potentially unsafe occurrence
of unsafeCoerce#, coercing from an unlifted to lifted type. However,
nowhere in the compiler do we assume that a BCO# is not a thunk.
Moreover, in the case of a CAF the result returned by `createBCO` *will*
be a thunk (as noted in [Updatable CAF BCOs]).  Consequently it seems
better to rather make BCO# a lifted type and rename it to BCO.

- - - - -
35afe4f3 by Sylvain Henry at 2019-12-03T07:12:13-05:00
Use Int# primops in `Bits Int{8,16,32,64}` instances

- - - - -
7a51b587 by Sylvain Henry at 2019-12-03T07:12:13-05:00
Add constant folding rule (#16402)

    narrowN (x .&. m)
    m .&. (2^N-1) = 2^N-1
    ==> narrowN x

e.g.  narrow16 (x .&. 0x12FFFF) ==> narrow16 x

- - - - -
10caee7f by Ben Gamari at 2019-12-03T21:04:50-05:00
users-guide: Add 8.12.1 release notes

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25019d18 by Ben Gamari at 2019-12-03T21:04:50-05:00
Drop Uniquable constraint for AnnTarget

This relied on deriveUnique, which was far too subtle to be safely
applied. Thankfully the instance doesn't appear to be used so let's just
drop it.

- - - - -
78b67ad0 by Ben Gamari at 2019-12-03T21:04:50-05:00
Simplify uniqAway

This does two things:

 * Eliminate all uses of Unique.deriveUnique, which was quite easy to
   mis-use and extremely subtle.

 * Rename the previous "derived unique" notion to "local unique". This
   is possible because the only places where `uniqAway` can be safely
   used are those where local uniqueness (with respect to some
   InScopeSet) is sufficient.

 * Rework the implementation of VarEnv.uniqAway, as discussed in #17462.
   This should make the operation significantly more efficient than its
   previous iterative implementation..

Metric Decrease:
    T9872c
    T12227
    T9233
    T14683
    T5030
    T12545
    hie002

Metric Increase:
    T9961

- - - - -
f03a41d4 by Ben Gamari at 2019-12-03T21:05:27-05:00
Elf: Fix link info note generation

Previously we would use the `.int` assembler directive to generate
32-bit words in the note section. However, `.int` is note guaranteed to
produce 4-bytes; in fact, on some platforms (e.g. AArch64) it produces
8-bytes. Use the `.4bytes` directive to avoid this.

Moreover, we used the `.align` directive, which is quite platform
dependent. On AArch64 it appears to not even be idempotent (despite what
the documentation claims). `.balign` is consequentially preferred as it
offers consistent behavior across platforms.

- - - - -
84585e5e by Vladislav Zavialov at 2019-12-05T16:07:44-05:00
Meaning-preserving SCC annotations (#15730)

This patch implements GHC Proposal #176:
  https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0176-scc-parsing.rst

Before the change:

  1 /                    2 / 2 = 0.25
  1 / {-# SCC "name" #-} 2 / 2 = 1.0

After the change:

  1 /                    2 / 2 = 0.25
  1 / {-# SCC "name" #-} 2 / 2 = parse error

- - - - -
e49e5470 by Vladislav Zavialov at 2019-12-05T16:07:44-05:00
Improve error messages for SCC pragmas

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a2b535d9 by Ben Gamari at 2019-12-05T16:07:45-05:00
users guide: Try to silence underfull \hbox warnings

We use two tricks, as suggested here [1]:

 * Use microtype to try to reduce the incidence of underfull boxes
 * Bump up \hbadness to eliminate the warnings

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4e47217f by Bodigrim at 2019-12-05T16:07:47-05:00
Make sameNat and sameSymbol proxy-polymorphic

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8324f0b7 by Bodigrim at 2019-12-05T16:07:47-05:00
Test proxy-polymorphic sameNat and sameSymbol

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69001f54 by Ben Gamari at 2019-12-05T16:07:48-05:00
nonmoving: Clear segment bitmaps during sweep

Previously we would clear the bitmaps of segments which we are going to
sweep during the preparatory pause. However, this is unnecessary: the
existence of the mark epoch ensures that the sweep will correctly
identify non-reachable objects, even if we do not clear the bitmap.

We now defer clearing the bitmap to sweep, which happens concurrently
with mutation.

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58a9c429 by Ben Gamari at 2019-12-05T16:07:48-05:00
testsuite: Disable divByZero on non-NCG targets

The LLVM backend does not guarantee any particular semantics for
division by zero, making this test unreliable across platforms.

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8280bd8a by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Factor out terminal coloring

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92a52aaa by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Make performance metric summary more readable

Along with some refactoring.

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c4ca29c7 by Ben Gamari at 2019-12-05T16:07:49-05:00
testsuite: Use colors more consistently

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3354c68e by Vladislav Zavialov at 2019-12-05T16:07:49-05:00
Pretty-printing of the * kind

Before this patch, GHC always printed the * kind unparenthesized.

This led to two issues:

1. Sometimes GHC printed invalid or incorrect code.
   For example, GHC would print:  type F @*   x = x
         when it meant to print:  type F @(*) x = x
   In the former case, instead of a kind application we were getting a
   type operator (@*).

2. Sometimes GHC printed kinds that were correct but hard to read.
   Should  Either * Int  be read as  Either (*) Int
                              or as  (*) Either Int  ?
   This depends on whether -XStarIsType is enabled, but it would be
   easier if we didn't have to check for the flag when reading the code.

We can solve both problems by assigning (*) a different precedence. Note
that Haskell98 kinds are not affected:

  ((* -> *) -> *) -> *  does NOT become  (((*) -> (*)) -> (*)) -> (*)

The parentheses are added when (*) is used in a function argument
position:

   F * * *   becomes  F (*) (*) (*)
   F A * B   becomes  F A (*) B
   Proxy *   becomes  Proxy (*)
   a * -> *  becomes  a (*) -> *

- - - - -
70dd0e4b by Vladislav Zavialov at 2019-12-05T16:07:49-05:00
Parenthesize the * kind in TH.Ppr

- - - - -
a7a4efbf by Ben Gamari at 2019-12-05T16:07:49-05:00
rts/NonMovingSweep: Fix locking of new mutable list allocation

Previously we used allocBlockOnNode_sync in nonmovingSweepMutLists
despite the fact that we aren't in the GC and therefore the allocation
spinlock isn't in use. This meant that sweep would end up spinning until
the next minor GC, when the SM lock was moved away from the SM_MUTEX to
the spinlock. This isn't a correctness issue but it sure isn't good for
performance.

Found thanks for Ward.

Fixes #17539.

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f171b358 by Matthias Braun at 2019-12-05T16:07:51-05:00
Fix typo in documentation of Base.hs.
- - - - -
9897e8c8 by Gabor Greif at 2019-12-06T21:20:38-05:00
Implement pointer tagging for big families (#14373)

Formerly we punted on these and evaluated constructors always got a tag
of 1.

We now cascade switches because we have to check the tag first and when
it is MAX_PTR_TAG then get the precise tag from the info table and
switch on that. The only technically tricky part is that the default
case needs (logical) duplication. To do this we emit an extra label for
it and branch to that from the second switch. This avoids duplicated
codegen.

Here's a simple example of the new code gen:

    data D = D1 | D2 | D3 | D4 | D5 | D6 | D7 | D8

On a 64-bit system previously all constructors would be tagged 1. With
the new code gen D7 and D8 are tagged 7:

    [Lib.D7_con_entry() {
         ...
         {offset
           c1eu: // global
               R1 = R1 + 7;
               call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
         }
     }]

    [Lib.D8_con_entry() {
         ...
         {offset
           c1ez: // global
               R1 = R1 + 7;
               call (P64[Sp])(R1) args: 8, res: 0, upd: 8;
         }
     }]

When switching we now look at the info table only when the tag is 7. For
example, if we derive Enum for the type above, the Cmm looks like this:

    c2Le:
        _s2Js::P64 = R1;
        _c2Lq::P64 = _s2Js::P64 & 7;
        switch [1 .. 7] _c2Lq::P64 {
            case 1 : goto c2Lk;
            case 2 : goto c2Ll;
            case 3 : goto c2Lm;
            case 4 : goto c2Ln;
            case 5 : goto c2Lo;
            case 6 : goto c2Lp;
            case 7 : goto c2Lj;
        }

    // Read info table for tag
    c2Lj:
        _c2Lv::I64 = %MO_UU_Conv_W32_W64(I32[I64[_s2Js::P64 & (-8)] - 4]);
        if (_c2Lv::I64 != 6) goto c2Lu; else goto c2Lt;

Generated Cmm sizes do not change too much, but binaries are very
slightly larger, due to the fact that the new instructions are longer in
encoded form. E.g. previously entry code for D8 above would be

    00000000000001c0 <Lib_D8_con_info>:
     1c0:	48 ff c3             	inc    %rbx
     1c3:	ff 65 00             	jmpq   *0x0(%rbp)

With this patch

    00000000000001d0 <Lib_D8_con_info>:
     1d0:	48 83 c3 07          	add    $0x7,%rbx
     1d4:	ff 65 00             	jmpq   *0x0(%rbp)

This is one byte longer.

Secondly, reading info table directly and then switching is shorter

    _c1co:
            movq -1(%rbx),%rax
            movl -4(%rax),%eax
            // Switch on info table tag
            jmp *_n1d5(,%rax,8)

than doing the same switch, and then for the tag 7 doing another switch:

    // When tag is 7
    _c1ct:
            andq $-8,%rbx
            movq (%rbx),%rax
            movl -4(%rax),%eax
            // Switch on info table tag
            ...

Some changes of binary sizes in actual programs:

- In NoFib the worst case is 0.1% increase in benchmark "parser" (see
  NoFib results below). All programs get slightly larger.

- Stage 2 compiler size does not change.

- In "containers" (the library) size of all object files increases
  0.0005%. Size of the test program "bitqueue-properties" increases
  0.03%.

nofib benchmarks kindly provided by Ömer (@osa1):

NoFib Results
=============

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          +0.0%      0.0%      0.0%     +0.0%     +0.0%
             FS          +0.0%      0.0%      0.0%     +0.0%      0.0%
              S          +0.0%      0.0%     -0.0%      0.0%      0.0%
             VS          +0.0%      0.0%     -0.0%     +0.0%     +0.0%
            VSD          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
            VSM          +0.0%      0.0%      0.0%      0.0%      0.0%
           anna          +0.0%      0.0%     +0.1%     -0.9%     -0.0%
           ansi          +0.0%      0.0%     -0.0%     +0.0%     +0.0%
           atom          +0.0%      0.0%      0.0%      0.0%      0.0%
         awards          +0.0%      0.0%     -0.0%     +0.0%      0.0%
         banner          +0.0%      0.0%     -0.0%     +0.0%      0.0%
     bernouilli          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
   binary-trees          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          +0.0%      0.0%     +0.0%      0.0%     -0.0%
         boyer2          +0.0%      0.0%     +0.0%      0.0%     -0.0%
           bspt          +0.0%      0.0%     +0.0%     +0.0%      0.0%
      cacheprof          +0.0%      0.0%     +0.1%     -0.8%      0.0%
       calendar          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
       cichelli          +0.0%      0.0%     +0.0%      0.0%      0.0%
        circsim          +0.0%      0.0%     -0.0%     -0.1%     -0.0%
       clausify          +0.0%      0.0%     +0.0%     +0.0%      0.0%
  comp_lab_zift          +0.0%      0.0%     +0.0%      0.0%     -0.0%
       compress          +0.0%      0.0%     +0.0%     +0.0%      0.0%
      compress2          +0.0%      0.0%      0.0%      0.0%      0.0%
    constraints          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          +0.0%      0.0%     +0.0%      0.0%      0.0%
   cryptarithm2          +0.0%      0.0%     +0.0%     -0.0%      0.0%
            cse          +0.0%      0.0%     +0.0%     +0.0%      0.0%
   digits-of-e1          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         dom-lt          +0.0%      0.0%     +0.0%     +0.0%      0.0%
          eliza          +0.0%      0.0%     -0.0%     +0.0%      0.0%
          event          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         exp3_8          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
         expert          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
 fannkuch-redux          +0.0%      0.0%     +0.0%      0.0%      0.0%
          fasta          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fem          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            fft          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           fft2          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
       fibheaps          +0.0%      0.0%     +0.0%     +0.0%      0.0%
           fish          +0.0%      0.0%     +0.0%     +0.0%      0.0%
          fluid          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         fulsom          +0.0%      0.0%     +0.0%     -0.0%     +0.0%
         gamteb          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
            gcd          +0.0%      0.0%     +0.0%     +0.0%      0.0%
    gen_regexps          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         genfft          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
             gg          +0.0%      0.0%      0.0%     -0.0%      0.0%
           grep          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         hidden          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
            hpg          +0.0%      0.0%     +0.0%     -0.1%     -0.0%
            ida          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
          infer          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        integer          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          +0.0%      0.0%      0.0%     +0.0%      0.0%
   k-nucleotide          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        knights          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         lambda          +0.0%      0.0%     +1.2%     -6.1%     -0.0%
     last-piece          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           lcss          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           life          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
           lift          +0.0%      0.0%     +0.0%     +0.0%      0.0%
         linear          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      listcompr          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         mandel          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
        mandel2          +0.0%      0.0%     +0.0%     +0.0%     -0.0%
           mate          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
        minimax          +0.0%      0.0%     -0.0%     +0.0%     -0.0%
        mkhprog          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
     multiplier          +0.0%      0.0%      0.0%     +0.0%     -0.0%
         n-body          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
       nucleic2          +0.0%      0.0%     +0.0%     +0.0%     -0.0%
           para          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      paraffins          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         parser          +0.1%      0.0%     +0.4%     -1.7%     -0.0%
        parstof          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
            pic          +0.0%      0.0%     +0.0%      0.0%     -0.0%
       pidigits          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
         pretty          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         primes          +0.0%      0.0%     +0.0%      0.0%      0.0%
      primetest          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         prolog          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         puzzle          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
         queens          +0.0%      0.0%      0.0%     +0.0%     +0.0%
        reptile          +0.0%      0.0%     +0.0%     +0.0%      0.0%
reverse-complem          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          +0.0%      0.0%     +0.0%      0.0%     -0.0%
           rfib          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            rsa          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            scc          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
          sched          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            scs          +0.0%      0.0%     +0.0%     +0.0%      0.0%
         simple          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
          solid          +0.0%      0.0%     +0.0%     +0.0%      0.0%
        sorting          +0.0%      0.0%     +0.0%     -0.0%      0.0%
  spectral-norm          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          +0.0%      0.0%     +0.0%     -1.0%      0.0%
         symalg          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
            tak          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      transform          +0.0%      0.0%     +0.4%     -1.3%     +0.0%
       treejoin          +0.0%      0.0%     +0.0%     -0.0%      0.0%
      typecheck          +0.0%      0.0%     -0.0%     +0.0%      0.0%
        veritas          +0.0%      0.0%     +0.0%     -0.1%     +0.0%
           wang          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
      wave4main          +0.0%      0.0%     +0.0%      0.0%     -0.0%
   wheel-sieve1          +0.0%      0.0%     +0.0%     +0.0%     +0.0%
   wheel-sieve2          +0.0%      0.0%     +0.0%     +0.0%      0.0%
           x2n1          +0.0%      0.0%     +0.0%     +0.0%      0.0%
--------------------------------------------------------------------------------
            Min          +0.0%      0.0%     -0.0%     -6.1%     -0.0%
            Max          +0.1%      0.0%     +1.2%     +0.0%     +0.0%
 Geometric Mean          +0.0%     -0.0%     +0.0%     -0.1%     -0.0%

NoFib GC Results
================

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
        circsim          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          +0.0%      0.0%     -0.0%      0.0%     -0.0%
       fibheaps          +0.0%      0.0%      0.0%     -0.0%     -0.0%
         fulsom          +0.0%      0.0%      0.0%     -0.6%     -0.0%
       gc_bench          +0.0%      0.0%      0.0%      0.0%     -0.0%
           hash          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          +0.0%      0.0%      0.0%     -0.0%      0.0%
      mutstore1          +0.0%      0.0%      0.0%     -0.0%     -0.0%
      mutstore2          +0.0%      0.0%     +0.0%     -0.0%     -0.0%
          power          +0.0%      0.0%     -0.0%      0.0%     -0.0%
     spellcheck          +0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          +0.0%      0.0%     -0.0%     -0.6%     -0.0%
            Max          +0.0%      0.0%     +0.0%      0.0%      0.0%
 Geometric Mean          +0.0%     +0.0%     +0.0%     -0.1%     +0.0%

Fixes #14373

These performance regressions appear to be a fluke in CI. See the
discussion in !1742 for details.

Metric Increase:
    T6048
    T12234
    T12425
    Naperian
    T12150
    T5837
    T13035

- - - - -
ee07421f by Simon Peyton Jones at 2019-12-06T21:21:14-05:00
Work in progress on coercionLKind, coercionRKind

This is a preliminary patch for #17515

- - - - -
0a4ca9eb by Simon Peyton Jones at 2019-12-06T21:21:14-05:00
Split up coercionKind

This patch implements the idea in #17515, splitting `coercionKind` into:

 * `coercion{Left,Right}Kind`, which computes the left/right side of the
    pair
 * `coercionKind`, which computes the pair of coercible types

This is reduces allocation since we frequently only need only one side
of the pair. Specifically, we see the following improvements on x86-64
Debian 9:

| test     | new        | old           | relative chg. |
| :------- | ---------: | ------------: | ------------: |
| T5030	   | 695537752  | 747641152.0   | -6.97%        |
| T5321Fun | 449315744  | 474009040.0   | -5.21%        |
| T9872a   | 2611071400 | 2645040952.0  | -1.28%        |
| T9872c   | 2957097904 | 2994260264.0  | -1.24%        |
| T12227   | 773435072  | 812367768.0   | -4.79%        |
| T12545   | 3142687224 | 3215714752.0  | -2.27%        |
| T14683   | 9392407664 | 9824775000.0  | -4.40%        |

Metric Decrease:
    T12545
    T9872a
    T14683
    T5030
    T12227
    T9872c
    T5321Fun
    T9872b

- - - - -
d46a72e1 by Gabor Greif at 2019-12-09T12:05:15-05:00
Fix comment typos

The below is only necessary to fix the CI perf fluke that
happened in 9897e8c8ef0b19a9571ef97a1d9bb050c1ee9121:
-------------------------
Metric Decrease:
    T5837
    T6048
    T9020
    T12425
    T12234
    T13035
    T12150
    Naperian
-------------------------

- - - - -
e3bba7e4 by Micha Wiedenmann at 2019-12-10T19:52:44-05:00
users guide: Motivation of DefaultSignatures

- - - - -
843ceb38 by Ben Gamari at 2019-12-10T19:53:54-05:00
rts: Add a long form flag to enable the non-moving GC

The old flag, `-xn`, was quite cryptic. Here we add `--nonmoving-gc` in
addition.

- - - - -
921d3238 by Ryan Scott at 2019-12-10T19:54:34-05:00
Ignore unary constraint tuples during typechecking (#17511)

We deliberately avoid defining a magical `Unit%` class, for reasons
that I have expounded upon in the newly added
`Note [Ignore unary constraint tuples]` in `TcHsType`. However, a
sneaky user could try to insert `Unit%` into their program by way of
Template Haskell, leading to the interface-file error observed
in #17511. To avoid this, any time we encounter a unary constraint
tuple during typechecking, we drop the surrounding constraint tuple
application. This is safe to do since `Unit% a` and `a` would be
semantically equivalent (unlike other forms of unary tuples).

Fixes #17511.

- - - - -
436ec9f3 by Ben Gamari at 2019-12-10T19:55:37-05:00
gitlab-ci: Move changelog linting logic to shell script

Allowing it to be easily used locally.

- - - - -
2f6b434f by Ben Gamari at 2019-12-10T19:55:37-05:00
gitlab-ci: Move changelog linting logic to shell script

Allowing it to be easily used locally.

- - - - -
7a5a6e07 by Ben Gamari at 2019-12-10T19:56:25-05:00
base: Fix incorrect @since in GHC.Natural

Fixes #17547.

- - - - -
2bbfaf8a by Ben Gamari at 2019-12-10T19:57:01-05:00
hadrian: AArch64 supports the GHCi interpreter and SMP

I'm not sure how this was omitted from the list of supported
architectures.

- - - - -
8f1ceb67 by John Ericson at 2019-12-10T19:57:39-05:00
Move Int# section of primops.txt.pp

This matches the organization of the fixed-sized ones, and keeps each
Int* next to its corresponding Word*.

- - - - -
7a823b0f by John Ericson at 2019-12-10T19:57:39-05:00
Move Int64# and Word64# sections of primops.txt.pp

This way it is next to the other fixed-sized ones.

- - - - -
8dd9929a by Ben Gamari at 2019-12-10T19:58:19-05:00
testsuite: Add (broken) test for #17510

- - - - -
6e47a76a by Ben Gamari at 2019-12-10T19:58:59-05:00
Re-layout validate script

This script was previously a whitespace nightmare.

- - - - -
f80c4a66 by Crazycolorz5 at 2019-12-11T14:12:17-05:00
rts: Specialize hashing at call site rather than in struct.

Separate word and string hash tables on the type level, and do not store
the hashing function.  Thus when a different hash function is desire it
is provided upon accessing the table. This is worst case the same as
before the change, and in the majority of cases is better. Also mark the
functions for aggressive inlining to improve performance.  {F1686506}

Reviewers: bgamari, erikd, simonmar

Subscribers: rwbarton, thomie, carter

GHC Trac Issues: #13165

Differential Revision: https://phabricator.haskell.org/D4889

- - - - -
2d1b9619 by Richard Eisenberg at 2019-12-11T14:12:55-05:00
Warn on inferred polymorphic recursion

Silly users sometimes try to use visible dependent quantification
and polymorphic recursion without a CUSK or SAK. This causes
unexpected errors. So we now adjust expectations with a bit
of helpful messaging.

Closes #17541 and closes #17131.

test cases: dependent/should_fail/T{17541{,b},17131}

- - - - -
4dde485e by Oleg Grenrus at 2019-12-12T02:24:46-05:00
Add --show-unit-ids flag to ghc-pkg

I only added it into --simple-output and ghc-pkg check output;
there are probably other places where it can be adopted.

- - - - -
e6e1ec08 by Ben Gamari at 2019-12-12T02:25:33-05:00
testsuite: Simplify and clarify performance test baseline search

The previous implementation was extremely complicated, seemingly to
allow the local and CI namespaces to be searched incrementally. However,
it's quite unclear why this is needed and moreover the implementation
seems to have had quadratic runtime cost in the search depth(!).

- - - - -
29c4609c by Ben Gamari at 2019-12-12T02:26:19-05:00
testsuite: Add test for #17549

- - - - -
9f0ee253 by Ben Gamari at 2019-12-12T02:26:56-05:00
gitlab-ci: Move -dwarf and -debug jobs to full-build stage

This sacrifices some precision in favor of improving parallelism.

- - - - -
7179b968 by Ben Gamari at 2019-12-12T02:27:34-05:00
Revert "rts: Drop redundant flags for libffi"

This seems to have regressed builds using `--with-system-libffi`
(#17520).

This reverts commit 3ce18700f80a12c48a029b49c6201ad2410071bb.

- - - - -
cc7d5650 by Oleg Grenrus at 2019-12-16T10:20:56+02:00
Having no shake upper bound is irresposible

Given that shake is far from "done" API wise,
and is central component to the build system.

- - - - -
9431f905 by Oleg Grenrus at 2019-12-16T10:55:50+02:00
Add index-state to hadrian/cabal.project

Then one is freer to omit upper bounds, as we won't pick
any new entries on Hackage while building hadrian itself.

- - - - -
3e17a866 by Krzysztof Gogolewski at 2019-12-16T19:31:44-05:00
Remove dataConSig

As suggested in #17291

- - - - -
75355fde by Krzysztof Gogolewski at 2019-12-16T19:31:44-05:00
Use "OrCoVar" functions less

As described in #17291, we'd like to separate coercions and expressions
in a more robust fashion.
This is a small step in this direction.

- `mkLocalId` now panicks on a covar.
  Calls where this was not the case were changed to `mkLocalIdOrCoVar`.
- Don't use "OrCoVar" functions in places where we know the type is
  not a coercion.

- - - - -
f9686e13 by Richard Eisenberg at 2019-12-16T19:32:21-05:00
Do more validity checks for quantified constraints

Close #17583.

Test case: typecheck/should_fail/T17563

- - - - -
af763765 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Fix Windows artifact collection

Variable interpolation in gitlab-ci.yml apparently doesn't work. Sigh.

- - - - -
e6d4b902 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Use xz --threads on Debian 10

- - - - -
8ba650e9 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Allow debian 8 build to fail

The python release shipped with deb8 (3.3) is too old for our testsuite
driver.

- - - - -
ac25a3f6 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Use xz --threads on Alpine

- - - - -
cc628088 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Another approach for xz detection

- - - - -
37d788ab by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Re-add release-x86_64-deb9 job

Also eliminate some redundancy.

- - - - -
f8279138 by Ben Gamari at 2019-12-16T19:33:01-05:00
gitlab-ci: Drop redundant release-x86_64-linux-deb9 job

- - - - -
8148ff06 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark cgrun057 as broken on ARMv7

Due to #17554. It's very surprising that this only occurs on ARMv7 but
this is the only place I've seen this failure thusfar.

- - - - -
85e5696d by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark prog001 as fragile on ARMv7

Due to #17555.

- - - - -
a5f0aab0 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T10272 as broken on ARMv7

Due to #17556.

- - - - -
1e6827c6 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T13825-debugger as broken on ARMv7

Due to #17557.

- - - - -
7cef0b7d by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T14028 as broken on ARMv7

Due to #17558.

- - - - -
6ea4eb4b by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Make ghc_built_by_llvm check more precise

Previously it would hackily look at the flavour name to determine
whether LLVM was used to build stage2 ghc. However, this didn't work at
all with Hadrian and would miss cases like ARM where we use the LLVM
backend by default.

See #16087 for the motivation for why ghc_built_by_llvm is needed at
all. This should catch one of the ARMv7 failures described in #17555.

- - - - -
c3e82bf7 by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark T5435_* tests as broken on ARM

`T5435_v_asm_a`, `T5435_v_asm_b`, and `T5435_v_gcc` all fail on ARMv7.
See #17559.

- - - - -
eb2aa851 by Ben Gamari at 2019-12-17T07:24:40-05:00
gitlab-ci: Don't allow armv7 jobs to fail

- - - - -
efc92216 by Ben Gamari at 2019-12-17T07:24:40-05:00
Revert "testsuite: Mark cgrun057 as broken on ARMv7"

This reverts commit 6cfc47ec8a478e1751cb3e7338954da1853c3996.

- - - - -
1d2bb9eb by Ben Gamari at 2019-12-17T07:24:40-05:00
testsuite: Mark print002 as fragile on ARM

Due to #17557.

Also accepting spurious performance change.

Metric Decrease:
    T1969

- - - - -
41f4e4fb by Josh Meredith at 2019-12-17T07:25:17-05:00
Fix ambiguous occurence error when building Hadrian

- - - - -
4374983a by Josh Meredith at 2019-12-17T07:25:17-05:00
Rename SphinxMode constructors

- - - - -
a8f7ecd5 by Josh Meredith at 2019-12-17T07:25:17-05:00
Use *Mode suffix instead of *M

- - - - -
58655b9d by Sylvain Henry at 2019-12-18T13:43:37+01:00
Add GHC-API logging hooks

* Add 'dumpAction' hook to DynFlags.

It allows GHC API users to catch dumped intermediate codes and
information. The format of the dump (Core, Stg, raw text, etc.) is now
reported allowing easier automatic handling.

* Add 'traceAction' hook to DynFlags.

Some dumps go through the trace mechanism (for instance unfoldings that
have been considered for inlining). This is problematic because:
1) dumps aren't written into files even with -ddump-to-file on
2) dumps are written on stdout even with GHC API
3) in this specific case, dumping depends on unsafe globally stored
DynFlags which is bad for GHC API users

We introduce 'traceAction' hook which allows GHC API to catch those
traces and to avoid using globally stored DynFlags.

* Avoid dumping empty logs via dumpAction/traceAction (but still write
empty files to keep the existing behavior)

- - - - -
fad866e0 by Moritz Kiefer at 2019-12-19T11:15:39-05:00
Avoid race condition in hDuplicateTo

In our codebase we have some code along the lines of

```
newStdout <- hDuplicate stdout
stderr `hDuplicateTo` stdout
```

to avoid stray `putStrLn`s from corrupting a protocol (LSP) that is
run over stdout.

On CI we have seen a bunch of issues where `dup2` returned `EBUSY` so
this fails with `ResourceExhausted` in Haskell.

I’ve spent some time looking at the docs for `dup2` and the code in
`base` and afaict the following race condition is being triggered
here:

1. The user calls `hDuplicateTo stderr stdout`.
2. `hDuplicateTo` calls `hClose_help stdout_`, this closes the file
handle for stdout.
3. The file handle for stdout is now free, so another thread
allocating a file might get stdout.
4. If `dup2` is called while `stdout` (now pointing to something
else) is half-open, it returns EBUSY.

I think there might actually be an even worse case where `dup2` is run
after FD 1 is fully open again. In that case, you will end up not just
redirecting the original stdout to stderr but also the whatever
resulted in that file handle being allocated.

As far as I can tell, `dup2` takes care of closing the file handle
itself so there is no reason to do this in `hDuplicateTo`. So this PR
replaces the call to `hClose_help` by the only part of `hClose_help`
that we actually care about, namely, `flushWriteBuffer`.

I tested this on our codebase fairly extensively and haven’t been able
to reproduce the issue with this patch.

- - - - -
0c114c65 by Sylvain Henry at 2019-12-19T11:16:17-05:00
Handle large ARR_WORDS in heap census (fix #17572)

We can do a heap census with a non-profiling RTS. With a non-profiling
RTS we don't zero superfluous bytes of shrunk arrays hence a need to
handle the case specifically to avoid a crash.

Revert part of a586b33f8e8ad60b5c5ef3501c89e9b71794bbed

- - - - -
1a0d1a65 by John Ericson at 2019-12-20T10:50:22-05:00
Deduplicate copied monad failure handler code

- - - - -
70e56b27 by Ryan Scott at 2019-12-20T10:50:57-05:00
lookupBindGroupOcc: recommend names in the same namespace (#17593)

Previously, `lookupBindGroupOcc`'s error message would recommend all
similar names in scope, regardless of whether they were type
constructors, data constructors, or functions, leading to the
confusion witnessed in #17593. This is easily fixed by only
recommending names in the same namespace, using the
`nameSpacesRelated` function.

Fixes #17593.

- - - - -
3c12355e by Stefan Schulze Frielinghaus at 2019-12-24T01:03:44-05:00
Fix endian handling w.r.t. CPP macro WORDS_BIGENDIAN

Include header file `ghcautoconf.h` where the CPP macro
`WORDS_BIGENDIAN` is defined. This finally fixes #17337 (in conjunction
with commit 6c59cc71dc).

- - - - -
11f8eef5 by Stefan Schulze Frielinghaus at 2019-12-24T01:03:44-05:00
fixup! Fix endian handling w.r.t. CPP macro WORDS_BIGENDIAN

- - - - -
40327b03 by Sylvain Henry at 2019-12-24T01:04:24-05:00
Remove outdated comment

- - - - -
aeea92ef by Sylvain Henry at 2019-12-25T19:23:54-05:00
Switch to ReadTheDocs theme for the user-guide

- - - - -
26493eab by Gabor Greif at 2019-12-25T19:24:32-05:00
Fix copy-paste error in comment
- - - - -
776df719 by Gabor Greif at 2019-12-25T19:24:32-05:00
Fix comment about minimal gcc version

to be consistent what FP_GCC_VERSION requires
- - - - -
3b17114d by Ömer Sinan Ağacan at 2019-12-26T14:09:11-05:00
Minor refactor in ghc.cabal.in:

- Remove outdated comments
- Move cutils.c from parser to cbits
- Remove unused cutils.h

- - - - -
334290b6 by Ryan Scott at 2019-12-26T14:09:48-05:00
Replace panic/notHandled with noExtCon in DsMeta

There are many spots in `DsMeta` where `panic` or `notHandled` is
used after pattern-matching on a TTG extension constructor. This is
overkill, however, as using `noExtCon` would work just as well. This
patch switches out these panics for `noExtCon`.

- - - - -
68252aa3 by Ben Gamari at 2019-12-27T15:11:38-05:00
testsuite: Skip T17499 when built against integer-simple

Since it routinely times out in CI.

- - - - -
0c51aeeb by Gabor Greif at 2019-12-27T15:12:17-05:00
suppress popup dialog about missing Xcode at configure

tested with `bash` and `zsh`.

- - - - -
8d76bcc2 by Gabor Greif at 2019-12-27T15:12:17-05:00
while at it rename XCode to the official Xcode

- - - - -
47a68205 by Ben Gamari at 2019-12-27T15:12:55-05:00
testsuite: Mark cgrun057 as fragile on ARM

As reported in #17554. Only marking on ARM for now although there is
evidence to suggest that the issue may occur on other platforms as well.

- - - - -
d03dec8f by Gabor Greif at 2019-12-27T15:13:32-05:00
use shell variable CcLlvmBackend for test

Previously we used `AC_DEFINE`d variable `CC_LLVM_BACKEND` which has an empty shell expansion.
- - - - -
2528e684 by Ben Gamari at 2019-12-30T06:51:32-05:00
driver: Include debug level in the recompilation check hash

Fixes #17586.

- - - - -
f14bb50b by Ben Gamari at 2019-12-30T06:52:09-05:00
rts: Ensure that nonmoving gc isn't used with profiling

- - - - -
b426de37 by Ben Gamari at 2019-12-30T06:52:45-05:00
llvmGen: Ensure that entry labels don't have predecessors

The LLVM IR forbids the entry label of a procedure from having any
predecessors. In the case of a simple looping function the LLVM code
generator broke this invariant, as noted in #17589. Fix this by
moving the function prologue to its own basic block, as suggested by
@kavon in #11649.

Fixes #11649 and #17589.

- - - - -
613f7265 by Ben Gamari at 2019-12-30T06:52:45-05:00
llvmGen: Drop old fix for #11649

This was a hack which is no longer necessary now since we introduce a
dedicated entry block for each procedure.

- - - - -
fdeffa5e by Ben Gamari at 2019-12-30T06:53:23-05:00
rts: Error on invalid --numa flags

Previously things like `+RTS --numa-debug` would enable NUMA support,
despite being an invalid flag.

- - - - -
9ce3ba68 by Ben Gamari at 2019-12-30T06:53:23-05:00
rts: Fix --debug-numa mode under Docker

As noted in #17606, Docker disallows the get_mempolicy syscall by
default. This caused numerous tests to fail under CI in the `debug_numa`
way. Avoid this by disabling the NUMA probing logic when --debug-numa is
in use, instead setting n_numa_nodes in RtsFlags.c.

Fixes #17606.

- - - - -
5baa2a43 by Ben Gamari at 2019-12-30T06:54:01-05:00
testsuite: Disable derefnull when built with LLVM

LLVM does not guarantee any particular semantics when dereferencing null
pointers. Consequently, this test actually passes when built with the
LLVM backend.

- - - - -
bd544d3d by Ben Gamari at 2019-12-30T06:54:38-05:00
hadrian: Track hash of Cabal Setup builder arguments

Lest we fail to rebuild when they change. Fixes #17611.

- - - - -
6e2c495e by Ben Gamari at 2019-12-30T06:55:19-05:00
TcIface: Fix inverted logic in typechecking of source ticks

Previously we would throw away source ticks when the debug level was
non-zero. This is precisely the opposite of what was intended.

Fixes #17616.

Metric Decrease:
    T13056
    T9020
    T9961
    T12425

- - - - -
7fad387d by Ben Gamari at 2019-12-30T06:55:55-05:00
perf_notes: Add --zero-y argument

This makes it easier to see the true magnitude of fluctuations.
Also do some house-keeping in the argument parsing department.

- - - - -
0d42b287 by Ben Gamari at 2019-12-30T06:55:55-05:00
testsuite: Enlarge acceptance window for T1969

As noted in #17624, it's quite unstable, especially, for some reason, on
i386 and armv7 (something about 32-bit platforms perhaps?).

Metric Increase:
    T1969

- - - - -
eb608235 by Sylvain Henry at 2019-12-31T14:22:32-05:00
Module hierarchy (#13009): Stg

- - - - -
d710fd66 by Vladislav Zavialov at 2019-12-31T14:23:10-05:00
Testsuite: update some Haddock tests

Fixed tests:

* haddockA039: added to all.T
* haddockE004: replaced with T17561 (marked as expect_broken)

New tests:

* haddockA040: deriving clause for a data instance
* haddockA041: haddock and CPP #include

- - - - -
859ebdd4 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Add "-Iw" RTS flag for minimum wait between idle GCs (#11134)

- - - - -
dd4b6551 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Add additional Note explaining the -Iw flag

- - - - -
c4279ff1 by Kevin Buhr at 2019-12-31T23:44:39-05:00
Fix some sloppy indentation

- - - - -
b84c09d5 by Ömer Sinan Ağacan at 2019-12-31T23:45:19-05:00
Tweak Cmm dumps to avoid generating sections for empty groups

When dumping Cmm groups check if the group is empty, to avoid generating
empty sections in dump files like

    ==================== Output Cmm ====================
    []

Also fixes a few bad indentation in the code around changes.

- - - - -
b2e0323f by Gabor Greif at 2020-01-03T21:22:36-05:00
Simplify mrStr

- - - - -
3c9dc06b by Brian Wignall at 2020-01-04T15:55:06-05:00
Fix typos, via a Levenshtein-style corrector

- - - - -
d561c8f6 by Sylvain Henry at 2020-01-04T15:55:46-05:00
Add Cmm related hooks

* stgToCmm hook
* cmmToRawCmm hook

These hooks are used by Asterius and could be useful to other clients of
the GHC API.

It increases the Parser dependencies (test CountParserDeps) to 184. It's
still less than 200 which was the initial request (cf
https://mail.haskell.org/pipermail/ghc-devs/2019-September/018122.html)
so I think it's ok to merge this.

- - - - -
ae6b6276 by Oleg Grenrus at 2020-01-04T15:56:22-05:00
Update to Cabal submodule to v3.2.0.0-alpha3

Metric Increase:
    haddock.Cabal

- - - - -
073f7cfd by Vladislav Zavialov at 2020-01-04T15:56:59-05:00
Add lexerDbg to dump the tokens fed to the parser

This a small utility function that comes in handy when debugging the
lexer and the parser.

- - - - -
558d4d4a by Sylvain Henry at 2020-01-04T15:57:38-05:00
Split integerGmpInternals test in several parts

This is to prepare for ghc-bignum which implements some but not all of
gmp functions.

- - - - -
4056b966 by Ben Gamari at 2020-01-04T15:58:15-05:00
testsuite: Mark cgrun057 as fragile on all platforms

I have seen this fail both on x86-64/Debian 9 and armv7/Debian 9

See #17554.

- - - - -
5ffea0c6 by Tamar Christina at 2020-01-06T18:38:37-05:00
Fix overflow.

- - - - -
99a9f51b by Sylvain Henry at 2020-01-06T18:39:22-05:00
Module hierarchy: Iface (cf #13009)

- - - - -
7aa4a061 by Ben Gamari at 2020-01-07T13:11:48-05:00
configure: Only check GCC version if CC is GCC

Also refactor FP_GCC_EXTRA_FLAGS in a few ways:

 * We no longer support compilers which lack support for -fno-builtin
   and -fwrapv so remove the condition on GccVersion
 * These flags are only necessary when using the via-C backend
   so make them conditional on Unregisterised.

Fixes #15742.

- - - - -
0805ed7e by John Ericson at 2020-01-07T13:12:25-05:00
Use non-empty lists to remove partiality in matching code

- - - - -
7844f3a8 by Ben Gamari at 2020-01-07T13:13:02-05:00
testsuite: Mark T17073 as broken on Windows

Due to #17607.

- - - - -
acf40cae by Ben Gamari at 2020-01-07T13:13:02-05:00
gitlab-ci: Disallow Windows from failing

- - - - -
34bc02c7 by Ben Gamari at 2020-01-07T13:13:02-05:00
configure: Find Python3 for testsuite

In addition, we prefer the Mingw64 Python distribution on Windows due
to #17483.

- - - - -
e35fe8d5 by Ben Gamari at 2020-01-07T13:13:02-05:00
testsuite: Fix Windows platform test

Previously we used platform.system() and while this worked fine (e.g.
returned `Windows`, as expected) locally under both msys and MingW64
Python distributions, it inexplicably returned `MINGW64_NT-10.0`
under MingW64 Python on CI. It seems os.name is more reliable so we now
use that instead..

- - - - -
48ef6217 by Ben Gamari at 2020-01-07T13:13:39-05:00
gitlab-ci: Rename push-test-metrics.sh to test-metrics.sh

Refactoring to follow.

- - - - -
2234fa92 by Ben Gamari at 2020-01-07T13:13:39-05:00
gitlab-ci: Pull test metrics before running testsuite

Otherwise the testsuite driver may not have an up-to-date
baseline.

- - - - -
1ca9adbc by Sylvain Henry at 2020-01-07T13:14:18-05:00
Remove `parallel` check from configure.ac

`parallel` is no longer a submodule since 3cb063c805ec841ca33b8371ef8aba9329221b6c

- - - - -
b69a3460 by Ryan Scott at 2020-01-07T13:14:57-05:00
Monomorphize HsModule to GhcPs (#17642)

Analyzing the call sites for `HsModule` reveals that it is only ever
used with parsed code (i.e., `GhcPs`). This simplifies `HsModule` by
concretizing its `pass` parameter to always be `GhcPs`.

Fixes #17642.

- - - - -
d491a679 by Sylvain Henry at 2020-01-08T06:16:31-05:00
Module hierarchy: Renamer (cf #13009)

- - - - -
d589410f by Ben Gamari at 2020-01-08T06:17:09-05:00
Bump haskeline submodule to 0.8.0.1

(cherry picked from commit feb3b955402d53c3875dd7a9a39f322827e5bd69)

- - - - -
923a1272 by Ryan Scott at 2020-01-08T06:17:47-05:00
Print Core type applications with no whitespace after @ (#17643)

This brings the pretty-printer for Core in line with how visible
type applications are normally printed: namely, with no whitespace
after the `@` character (i.e., `f @a` instead of `f @ a`). While I'm
in town, I also give the same treatment to type abstractions (i.e.,
`\(@a)` instead of `\(@ a)`) and coercion applications (i.e.,
`f @~x` instead of `f @~ x`).

Fixes #17643.

- - - - -
49f83a0d by Adam Sandberg Eriksson at 2020-01-12T21:28:09-05:00
improve docs for HeaderInfo.getImports

[skip ci]

- - - - -
9129210f by Matthew Pickering at 2020-01-12T21:28:47-05:00
Overloaded Quotation Brackets (#246)

This patch implements overloaded quotation brackets which generalise the
desugaring of all quotation forms in terms of a new minimal interface.

The main change is that a quotation, for example, [e| 5 |], will now
have type `Quote m => m Exp` rather than `Q Exp`. The `Quote` typeclass
contains a single method for generating new names which is used when
desugaring binding structures.

The return type of functions from the `Lift` type class, `lift` and `liftTyped` have
been restricted to `forall m . Quote m => m Exp` rather than returning a
result in a Q monad.

More details about the feature can be read in the GHC proposal.

https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0246-overloaded-bracket.rst

- - - - -
350e2b78 by Richard Eisenberg at 2020-01-12T21:29:27-05:00
Don't zap to Any; error instead

This changes GHC's treatment of so-called Naughty Quantification
Candidates to issue errors, instead of zapping to Any.

Close #16775.

No new test cases, because existing ones cover this well.

- - - - -
0b5ddc7f by Brian Wignall at 2020-01-12T21:30:08-05:00
Fix more typos, via an improved Levenshtein-style corrector

- - - - -
f732dbec by Ben Gamari at 2020-01-12T21:30:49-05:00
gitlab-ci: Retain bindists used by head.hackage for longer

Previously we would keep them for two weeks. However, on the stable
branches two weeks can easily elapse with no pushes.

- - - - -
c8636da5 by Sylvain Henry at 2020-01-12T21:31:30-05:00
Fix LANG=C for readelf invocation in T14999

The test fails when used with LANG=fr_FR.UTF-8

- - - - -
077a88de by Jean-Baptiste Mazon at 2020-01-12T21:32:08-05:00
users-guide/debug-info: typo “behivior”
- - - - -
61916c5d by Simon Peyton Jones at 2020-01-12T21:32:44-05:00
Add comments about TH levels

- - - - -
1fd766ca by Simon Peyton Jones at 2020-01-12T21:32:44-05:00
Comments about constraint floating

- - - - -
de01427e by Simon Peyton Jones at 2020-01-12T21:32:45-05:00
Minor refactor around quantified constraints

This patch clarifies a dark corner of quantified
constraints.

* See Note [Yukky eq_sel for a HoleDest] in TcSMonad

* Minor refactor, breaking out new function
     TcInteract.doTopReactEqPred

- - - - -
30be3bf1 by Simon Peyton Jones at 2020-01-12T21:32:45-05:00
Comments in TcHsType

- - - - -
c5977d4d by Sebastian Graf at 2020-01-16T05:58:58-05:00
Better documentation for mkEtaWW [skip ci]

So that hopefully I understand it faster next time. Also got rid of the
confusing `orig_expr`, which makes the call site in `etaExpand` look out
of sync with the passed `n` (which is not the original `n`).

- - - - -
22c0bdc3 by John Ericson at 2020-01-16T05:59:37-05:00
Handle TagToEnum in the same big case as the other primops

Before, it was a panic because it was handled above. But there must have
been an error in my reasoning (another caller?) because #17442 reported
the panic was hit.

But, rather than figuring out what happened, I can just make it
impossible by construction. By adding just a bit more bureaucracy in the
return types, I can handle TagToEnum in the same case as all the others,
so the big case is is now total, and the panic is removed.

Fixes #17442

- - - - -
ee5d63f4 by John Ericson at 2020-01-16T05:59:37-05:00
Get rid of OpDest

`OpDest` was basically a defunctionalization. Just turn the code that
cased on it into those functions, and call them directly.

- - - - -
1ff55226 by John Ericson at 2020-01-16T06:00:16-05:00
Remove special case case of bool during STG -> C--

Allow removing the no longer needed cgPrimOp, getting rid of a small a
small layer violation too.

Change which made the special case no longer needed was #6135 /
6579a6c73082387f82b994305011f011d9d8382b, which dates back to 2013,
making me feel better.

- - - - -
f416fe64 by Adam Wespiser at 2020-01-16T06:00:53-05:00
replace dead html link (fixes #17661)

- - - - -
f6bf2ce8 by Sebastian Graf at 2020-01-16T06:01:32-05:00
Revert "`exprOkForSpeculation` for Note [IO hack in the demand analyser]"

This reverts commit ce64b397777408731c6dd3f5c55ea8415f9f565b on the
grounds of the regression it would introduce in a couple of packages.

Fixes #17653.

Also undoes a slight metric increase in #13701 introduced by that commit
that we didn't see prior to !1983.

Metric Decrease:
    T13701

- - - - -
a71323ff by Ben Gamari at 2020-01-17T08:43:16-05:00
gitlab-ci: Don't FORCE_SYMLINKS on Windows

Not all runners have symlink permissions enabled.
- - - - -
0499e3bc by Ömer Sinan Ağacan at 2020-01-20T15:31:33-05:00
Fix +RTS -Z flag documentation

Stack squeezing is done on context switch, not on GC or stack overflow.
Fix the documentation.

Fixes #17685

[ci skip]

- - - - -
a661df91 by Ömer Sinan Ağacan at 2020-01-20T15:32:13-05:00
Document Stg.FVs module

Fixes #17662

[ci skip]

- - - - -
db24e480 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Don't trash STG registers

Fixes #13904.

- - - - -
f3d7fdb3 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Fix typo in readnone attribute

- - - - -
442751c6 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Add lower-expect to the -O0 optimisation set

@kavon says that this will improve block layout for stack checks.

- - - - -
e90ecc93 by Ben Gamari at 2020-01-20T15:32:52-05:00
llvmGen: Fix #14251

Fixes the calling convention for functions passing raw SSE-register
values by adding padding as needed to get the values in the right
registers. This problem cropped up when some args were unused an dropped
from the live list.

This folds together 2e23e1c7de01c92b038e55ce53d11bf9db993dd4 and
73273be476a8cc6c13368660b042b3b0614fd928 previously from @kavon.

Metric Increase:
    T12707
    ManyConstructors

- - - - -
66e511a4 by Ben Gamari at 2020-01-20T15:33:28-05:00
testsuite: Preserve more information in framework failures

Namely print the entire exception in hopes that this will help track
down #17649.

- - - - -
b62b8cea by Ömer Sinan Ağacan at 2020-01-20T15:34:06-05:00
Remove deprecated -smp flag

It was deprecated in 2012 with 46258b40

- - - - -
0c04a86a by Ben Gamari at 2020-01-20T15:34:43-05:00
gitlab-ci: Reenable submodule linter

- - - - -
2bfabd22 by Ben Gamari at 2020-01-20T15:34:43-05:00
gitlab-ci: Allow submodule cleaning to fail on Windows

Currently CI is inexplicably failing with
```
$ git submodule foreach git clean -xdf
fatal: not a git repository: libffi-tarballs/../.git/modules/libffi-tarballs
```
I have no idea how this working tree got into such a state but we do
need to fail more gracefully when it happens. Consequently, we allow the
cleaning step to fail.

- - - - -
14bced99 by Xavier Denis at 2020-01-20T15:35:21-05:00
Put the docs for :instances in alphabetical position

- - - - -
7e0bb82b by Ben Gamari at 2020-01-20T15:35:57-05:00
Add missing Note [Improvement from Ground Wanteds]

Closes #17659.

- - - - -
17e43a7c by Ben Gamari at 2020-01-20T15:36:32-05:00
unregisterised: Fix declaration for stg_NO_FINALIZER

Previously it had a redundant _entry suffix. We never noticed this
previously presumably because we never generated references to it
(however hard to believe this may be). However, it did start failing in
!1304.

- - - - -
3dae006f by PHO at 2020-01-20T15:37:08-05:00
Avoid ./configure failure on NetBSD

- - - - -
738e2912 by Ben Gamari at 2020-01-24T13:42:56-05:00
testsuite: Widen acceptance window of T1969

I have seen >20% fluctuations in this number, leading to spurious
failures.

- - - - -
ad4eb7a7 by Gabor Greif at 2020-01-25T05:19:07-05:00
Document the fact, that openFileBlocking can consume an OS thread indefinitely.

Also state that a deadlock can happen with the non-threaded runtime.
[ci skip]
- - - - -
be910728 by Sebastian Graf at 2020-01-25T05:19:46-05:00
`-ddump-str-signatures` dumps Text, not STG [skip ci]

- - - - -
0e57d8a1 by Ömer Sinan Ağacan at 2020-01-25T05:20:27-05:00
Fix chaining tagged and untagged ptrs in compacting GC

Currently compacting GC has the invariant that in a chain all fields are tagged
the same. However this does not really hold: root pointers are not tagged, so
when we thread a root we initialize a chain without a tag. When the pointed
objects is evaluated and we have more pointers to it from the heap, we then add
*tagged* fields to the chain (because pointers to it from the heap are tagged),
ending up chaining fields with different tags (pointers from roots are NOT
tagged, pointers from heap are). This breaks the invariant and as a result
compacting GC turns tagged pointers into non-tagged.

This later causes problem in the generated code where we do reads assuming that
the pointer is aligned, e.g.

    0x7(%rax) -- assumes that pointer is tagged 1

which causes misaligned reads. This caused #17088.

We fix this using the "pointer tagging for large families" patch (#14373,
!1742):

- With the pointer tagging patch the GC can know what the tagged pointer to a
  CONSTR should be (previously we'd need to know the family size -- large
  families are always tagged 1, small families are tagged depending on the
  constructor).

- Since we now know what the tags should be we no longer need to store the
  pointer tag in the info table pointers when forming chains in the compacting
  GC.

As a result we no longer need to tag pointers in chains with 1/2 depending on
whether the field points to an info table pointer, or to another field: an info
table pointer is always tagged 0, everything else in the chain is tagged 1. The
lost tags in pointers can be retrieved by looking at the info table.

Finally, instead of using tag 1 for fields and tag 0 for info table pointers, we
use two different tags for fields:

- 1 for fields that have untagged pointers
- 2 for fields that have tagged pointers

When unchaining we then look at the pointer to a field, and depending on its tag
we either leave a tagged pointer or an untagged pointer in the field.

This allows chaining untagged and tagged fields together in compacting GC.

Fixes #17088

Nofib results
-------------

Binaries are smaller because of smaller `Compact.c` code.

make mode=fast EXTRA_RUNTEST_OPTS="-cachegrind" EXTRA_HC_OPTS="-with-rtsopts=-c" NoFibRuns=1

    --------------------------------------------------------------------------------
            Program           Size    Allocs    Instrs     Reads    Writes
    --------------------------------------------------------------------------------
                 CS          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                CSD          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                 FS          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
                  S          -0.3%      0.0%     +5.4%     +0.8%     +3.9%
                 VS          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
                VSD          -0.3%      0.0%     -0.0%     -0.0%     -0.2%
                VSM          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               anna          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
               ansi          -0.3%      0.0%     +0.1%     +0.0%     +0.0%
               atom          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             awards          -0.2%      0.0%     +0.0%      0.0%     -0.0%
             banner          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
         bernouilli          -0.3%      0.0%     +0.1%     +0.0%     +0.0%
       binary-trees          -0.2%      0.0%     +0.0%      0.0%     +0.0%
              boyer          -0.3%      0.0%     +0.2%     +0.0%     +0.0%
             boyer2          -0.2%      0.0%     +0.2%     +0.1%     +0.0%
               bspt          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
          cacheprof          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
           calendar          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           cichelli          -0.3%      0.0%     +1.1%     +0.2%     +0.5%
            circsim          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
           clausify          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
      comp_lab_zift          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
           compress          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
          compress2          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
        constraints          -0.3%      0.0%     +0.2%     +0.1%     +0.1%
       cryptarithm1          -0.3%      0.0%     +0.0%     -0.0%      0.0%
       cryptarithm2          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                cse          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
       digits-of-e1          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
       digits-of-e2          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
             dom-lt          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
              eliza          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
              event          -0.3%      0.0%     +0.1%     +0.0%     -0.0%
        exact-reals          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             exp3_8          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
             expert          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
     fannkuch-redux          -0.3%      0.0%     -0.0%     -0.0%     -0.0%
              fasta          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                fem          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                fft          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
               fft2          -0.2%      0.0%     +0.0%     -0.0%     +0.0%
           fibheaps          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               fish          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              fluid          -0.2%      0.0%     +0.4%     +0.1%     +0.1%
             fulsom          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             gamteb          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                gcd          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
        gen_regexps          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             genfft          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                 gg          -0.2%      0.0%     +0.7%     +0.3%     +0.2%
               grep          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             hidden          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                hpg          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
                ida          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              infer          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
            integer          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
          integrate          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
       k-nucleotide          -0.2%      0.0%     +0.0%     +0.0%     -0.0%
              kahan          -0.3%      0.0%     -0.0%     -0.0%     -0.0%
            knights          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             lambda          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
         last-piece          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               lcss          -0.3%      0.0%     +0.0%     +0.0%      0.0%
               life          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               lift          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             linear          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
          listcompr          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           listcopy          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
           maillist          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             mandel          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            mandel2          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
               mate          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            minimax          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            mkhprog          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
         multiplier          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             n-body          -0.2%      0.0%     -0.0%     -0.0%     -0.0%
           nucleic2          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
               para          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
          paraffins          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             parser          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            parstof          -0.2%      0.0%     +0.8%     +0.2%     +0.2%
                pic          -0.2%      0.0%     +0.1%     -0.1%     -0.1%
           pidigits          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
              power          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
             pretty          -0.3%      0.0%     -0.0%     -0.0%     -0.1%
             primes          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
          primetest          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
             prolog          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
             puzzle          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
             queens          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            reptile          -0.2%      0.0%     +0.2%     +0.1%     +0.0%
    reverse-complem          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            rewrite          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               rfib          -0.2%      0.0%     +0.0%     +0.0%     -0.0%
                rsa          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                scc          -0.3%      0.0%     -0.0%     -0.0%     -0.1%
              sched          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
                scs          -0.2%      0.0%     +0.1%     +0.0%     +0.0%
             simple          -0.2%      0.0%     +3.4%     +1.0%     +1.8%
              solid          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
            sorting          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
      spectral-norm          -0.2%      0.0%     -0.0%     -0.0%     -0.0%
             sphere          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
             symalg          -0.2%      0.0%     +0.0%     +0.0%     +0.0%
                tak          -0.3%      0.0%     +0.0%     +0.0%     -0.0%
          transform          -0.2%      0.0%     +0.2%     +0.1%     +0.1%
           treejoin          -0.3%      0.0%     +0.2%     -0.0%     -0.1%
          typecheck          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
            veritas          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
               wang          -0.2%      0.0%     +0.0%     -0.0%     -0.0%
          wave4main          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
       wheel-sieve1          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
       wheel-sieve2          -0.3%      0.0%     +0.0%     -0.0%     -0.0%
               x2n1          -0.3%      0.0%     +0.0%     +0.0%     +0.0%
    --------------------------------------------------------------------------------
                Min          -0.3%      0.0%     -0.0%     -0.1%     -0.2%
                Max          -0.1%      0.0%     +5.4%     +1.0%     +3.9%
     Geometric Mean          -0.3%     -0.0%     +0.1%     +0.0%     +0.1%

    --------------------------------------------------------------------------------
            Program           Size    Allocs    Instrs     Reads    Writes
    --------------------------------------------------------------------------------
            circsim          -0.2%      0.0%     +1.6%     +0.4%     +0.7%
        constraints          -0.3%      0.0%     +4.3%     +1.5%     +2.3%
           fibheaps          -0.3%      0.0%     +3.5%     +1.2%     +1.3%
             fulsom          -0.2%      0.0%     +3.6%     +1.2%     +1.8%
           gc_bench          -0.3%      0.0%     +4.1%     +1.3%     +2.3%
               hash          -0.3%      0.0%     +6.6%     +2.2%     +3.6%
               lcss          -0.3%      0.0%     +0.7%     +0.2%     +0.7%
          mutstore1          -0.3%      0.0%     +4.8%     +1.4%     +2.8%
          mutstore2          -0.3%      0.0%     +3.4%     +1.0%     +1.7%
              power          -0.2%      0.0%     +2.7%     +0.6%     +1.9%
         spellcheck          -0.3%      0.0%     +1.1%     +0.4%     +0.4%
    --------------------------------------------------------------------------------
                Min          -0.3%      0.0%     +0.7%     +0.2%     +0.4%
                Max          -0.2%      0.0%     +6.6%     +2.2%     +3.6%
     Geometric Mean          -0.3%     +0.0%     +3.3%     +1.0%     +1.8%

Metric changes
--------------

While it sounds ridiculous, this change causes increased allocations in
the following tests. We concluded that this change can't cause a
difference in allocations and decided to land this patch. Fluctuations
in "bytes allocated" metric is tracked in #17686.

Metric Increase:
    Naperian
    T10547
    T12150
    T12234
    T12425
    T13035
    T5837
    T6048

- - - - -
8038cbd9 by Sebastian Graf at 2020-01-25T05:21:05-05:00
PmCheck: Formulate as translation between Clause Trees

We used to check `GrdVec`s arising from multiple clauses and guards in
isolation. That resulted in a split between `pmCheck` and
`pmCheckGuards`, the implementations of which were similar, but subtly
different in detail. Also the throttling mechanism described in
`Note [Countering exponential blowup]` ultimately got quite complicated
because it had to cater for both checking functions.

This patch realises that pattern match checking doesn't just consider
single guarded RHSs, but that it's always a whole set of clauses, each
of which can have multiple guarded RHSs in turn. We do so by
translating a list of `Match`es to a `GrdTree`:

```haskell
data GrdTree
  = Rhs !RhsInfo
  | Guard !PmGrd !GrdTree      -- captures lef-to-right  match semantics
  | Sequence !GrdTree !GrdTree -- captures top-to-bottom match semantics
  | Empty                      -- For -XEmptyCase, neutral element of Sequence
```

Then we have a function `checkGrdTree` that matches a given `GrdTree`
against an incoming set of values, represented by `Deltas`:

```haskell
checkGrdTree :: GrdTree -> Deltas -> CheckResult
...
```

Throttling is isolated to the `Sequence` case and becomes as easy as one
would expect: When the union of uncovered values becomes too big, just
return the original incoming `Deltas` instead (which is always a
superset of the union, thus a sound approximation).

The returned `CheckResult` contains two things:

1. The set of values that were not covered by any of the clauses, for
   exhaustivity warnings.
2. The `AnnotatedTree` that enriches the syntactic structure of the
   input program with divergence and inaccessibility information.

This is `AnnotatedTree`:

```haskell
data AnnotatedTree
  = AccessibleRhs !RhsInfo
  | InaccessibleRhs !RhsInfo
  | MayDiverge !AnnotatedTree
  | SequenceAnn !AnnotatedTree !AnnotatedTree
  | EmptyAnn
```

Crucially, `MayDiverge` asserts that the tree may force diverging
values, so not all of its wrapped clauses can be redundant.

While the set of uncovered values can be used to generate the missing
equations for warning messages, redundant and proper inaccessible
equations can be extracted from `AnnotatedTree` by
`redundantAndInaccessibleRhss`.

For this to work properly, the interface to the Oracle had to change.
There's only `addPmCts` now, which takes a bag of `PmCt`s. There's a
whole bunch of `PmCt` variants to replace the different oracle functions
from before.

The new `AnnotatedTree` structure allows for more accurate warning
reporting (as evidenced by a number of changes spread throughout GHC's
code base), thus we fix #17465.

Fixes #17646 on the go.

Metric Decrease:
    T11822
    T9233
    PmSeriesS
    haddock.compiler

- - - - -
86966d48 by Sebastian Graf at 2020-01-25T05:21:05-05:00
PmCheck: Properly handle constructor-bound type variables

In https://gitlab.haskell.org/ghc/ghc/merge_requests/2192#note_246551
Simon convinced me that ignoring type variables existentially bound by
data constructors have to be the same way as value binders.

Sadly I couldn't think of a regression test, but I'm confident that this
change strictly improves on the status quo.

- - - - -
c3fde723 by Ryan Scott at 2020-01-25T05:21:40-05:00
Handle local fixity declarations in DsMeta properly

`DsMeta.rep_sig` used to skip over `FixSig` entirely, which had the
effect of causing local fixity declarations to be dropped when quoted
in Template Haskell. But there is no good reason for this state of
affairs, as the code in `DsMeta.repFixD` (which handles top-level
fixity declarations) handles local fixity declarations just fine.
This patch factors out the necessary parts of `repFixD` so that they
can be used in `rep_sig` as well.

There was one minor complication: the fixity signatures for class
methods in each `HsGroup` were stored both in `FixSig`s _and_ the
list of `LFixitySig`s for top-level fixity signatures, so I needed
to take action to prevent fixity signatures for class methods being
converted to `Dec`s twice. I tweaked `RnSource.add` to avoid putting
these fixity signatures in two places and added
`Note [Top-level fixity signatures in an HsGroup]` in `GHC.Hs.Decls`
to explain the new design.

Fixes #17608. Bumps the Haddock submodule.

- - - - -
6e2d9ee2 by Sylvain Henry at 2020-01-25T05:22:20-05:00
Module hierarchy: Cmm (cf #13009)

- - - - -
8b726534 by PHO at 2020-01-25T05:23:01-05:00
Fix rts allocateExec() on NetBSD

Similar to SELinux, NetBSD "PaX mprotect" prohibits marking a page
mapping both writable and executable at the same time. Use libffi
which knows how to work around it.

- - - - -
6eb566a0 by Xavier Denis at 2020-01-25T05:23:39-05:00
Add ghc-in-ghci for stack based builds

- - - - -
b1a32170 by Xavier Denis at 2020-01-25T05:23:39-05:00
Create ghci.cabal.sh

- - - - -
0a5e4f5f by Sylvain Henry at 2020-01-25T05:24:19-05:00
Split glasgow_exts into several files (#17316)

- - - - -
b3e5c678 by Ben Gamari at 2020-01-25T05:24:57-05:00
hadrian: Throw error on duplicate-named flavours

Throw an error if the user requests a flavour for which there is more
than one match.

Fixes #17156.

- - - - -
0940b59a by Ryan Scott at 2020-01-25T08:15:05-05:00
Do not bring visible foralls into scope in hsScopedTvs

Previously, `hsScopedTvs` (and its cousin `hsWcScopedTvs`) pretended
that visible dependent quantification could not possibly happen at
the term level, and cemented that assumption with an `ASSERT`:

```hs
    hsScopedTvs (HsForAllTy { hst_fvf = vis_flag, ... }) =
      ASSERT( vis_flag == ForallInvis )
      ...
```

It turns out that this assumption is wrong. You can end up tripping
this `ASSERT` if you stick it to the man and write a type for a term
that uses visible dependent quantification anyway, like in this
example:

```hs
{-# LANGUAGE ScopedTypeVariables #-}

x :: forall a -> a -> a
x = x
```

That won't typecheck, but that's not the point. Before the
typechecker has a chance to reject this, the renamer will try
to use `hsScopedTvs` to bring `a` into scope over the body of `x`,
since `a` is quantified by a `forall`. This, in turn, causes the
`ASSERT` to fail. Bummer.

Instead of walking on this dangerous ground, this patch makes GHC
adopt a more hardline stance by pattern-matching directly on
`ForallInvis` in `hsScopedTvs`:

```hs
    hsScopedTvs (HsForAllTy { hst_fvf = ForallInvis, ... }) = ...
```

Now `a` will not be brought over the body of `x` at all (which is how
it should be), there's no chance of the `ASSERT` failing anymore (as
it's gone), and best of all, the behavior of `hsScopedTvs` does not
change. Everyone wins!

Fixes #17687.

- - - - -
1132602f by Ryan Scott at 2020-01-27T10:03:42-05:00
Use splitLHs{ForAll,Sigma}TyInvis throughout the codebase

Richard points out in #17688 that we use `splitLHsForAllTy` and
`splitLHsSigmaTy` in places that we ought to be using the
corresponding `-Invis` variants instead, identifying two bugs
that are caused by this oversight:

* Certain TH-quoted type signatures, such as those that appear in
  quoted `SPECIALISE` pragmas, silently turn visible `forall`s into
  invisible `forall`s.
* When quoted, the type `forall a -> (a ~ a) => a` will turn into
  `forall a -> a` due to a bug in `DsMeta.repForall` that drops
  contexts that follow visible `forall`s.

These are both ultimately caused by the fact that `splitLHsForAllTy`
and `splitLHsSigmaTy` split apart visible `forall`s in addition to
invisible ones. This patch cleans things up:

* We now use `splitLHsForAllTyInvis` and `splitLHsSigmaTyInvis`
  throughout the codebase. Relatedly, the `splitLHsForAllTy` and
  `splitLHsSigmaTy` have been removed, as they are easy to misuse.
* `DsMeta.repForall` now only handles invisible `forall`s to reduce
  the chance for confusion with visible `forall`s, which need to be
  handled differently. I also renamed it from `repForall` to
  `repForallT` to emphasize that its distinguishing characteristic
  is the fact that it desugars down to `L.H.TH.Syntax.ForallT`.

Fixes #17688.

- - - - -
97d0b0a3 by Matthew Pickering at 2020-01-27T10:04:19-05:00
Make Block.h compile with c++ compilers

- - - - -
4bada77d by Tom Ellis at 2020-01-27T12:30:46-05:00
Disable two warnings for files that trigger them

incomplete-uni-patterns and incomplete-record-updates will be in -Wall at a
future date, so prepare for that by disabling those warnings on files that
trigger them.

- - - - -
0188404a by Tom Ellis at 2020-01-27T12:30:46-05:00
Add two warnings to stage 2 build

- - - - -
acae02c1 by Tom Ellis at 2020-01-27T12:30:46-05:00
Add two warnings to Hadrian

- - - - -
bf38a20e by Sylvain Henry at 2020-01-31T02:46:15-05:00
Call `interpretPackageEnv` from `setSessionDynFlags`

interpretPackageEnv modifies the flags by reading the dreaded package
environments. It is much less surprising to call it from
`setSessionDynFlags` instead of reading package environments as a
side-effect of `initPackages`.

- - - - -
29c701c1 by Sylvain Henry at 2020-01-31T02:46:15-05:00
Refactor package related code

The package terminology is a bit of a mess. Cabal packages contain
components. Instances of these components when built with some
flags/options/dependencies are called units. Units are registered into
package databases and their metadata are called PackageConfig.

GHC only knows about package databases containing units. It is a sad
mismatch not fixed by this patch (we would have to rename parameters
such as `package-id <unit-id>` which would affect users).

This patch however fixes the following internal names:

- Renames PackageConfig into UnitInfo.
- Rename systemPackageConfig into globalPackageDatabase[Path]
- Rename PkgConfXX into PkgDbXX
- Rename pkgIdMap into unitIdMap
- Rename ModuleToPkgDbAll into ModuleNameProvidersMap
- Rename lookupPackage into lookupUnit
- Add comments on DynFlags package related fields

It also introduces a new `PackageDatabase` datatype instead of
explicitly passing the following tuple: `(FilePath,[PackageConfig])`.

The `pkgDatabase` field in `DynFlags` now contains the unit info for
each unit of each package database exactly as they have been read from
disk. Previously the command-line flag `-distrust-all-packages` would
modify these unit info. Now this flag only affects the "dynamic"
consolidated package state found in `pkgState` field. It makes sense
because `initPackages` could be called first with this
`distrust-all-packages` flag set and then again (using ghc-api) without
and it should work (package databases are not read again from disk when
`initPackages` is called the second time).

Bump haddock submodule

- - - - -
942c7148 by Ben Gamari at 2020-01-31T02:46:54-05:00
rename: Eliminate usage of mkVarOccUnique

Replacing it with `newSysName`. Fixes #17061.

- - - - -
41117d71 by Ben Gamari at 2020-01-31T02:47:31-05:00
base: Use one-shot kqueue on macOS

The underlying reason requiring that one-shot usage be disabled (#13903)
has been fixed.

Closes #15768.

- - - - -
01b15b83 by Ben Gamari at 2020-01-31T02:48:08-05:00
testsuite: Don't crash on encoding failure in print

If the user doesn't use a Unicode locale then the testsuite driver would
previously throw framework failures due to encoding failures. We now
rather use the `replace` error-handling strategy.

- - - - -
c846618a by Ömer Sinan Ağacan at 2020-01-31T12:21:10+03:00
Do CafInfo/SRT analysis in Cmm

This patch removes all CafInfo predictions and various hacks to preserve
predicted CafInfos from the compiler and assigns final CafInfos to
interface Ids after code generation. SRT analysis is extended to support
static data, and Cmm generator is modified to allow generating
static_link fields after SRT analysis.

This also fixes `-fcatch-bottoms`, which introduces error calls in case
expressions in CorePrep, which runs *after* CoreTidy (which is where we
decide on CafInfos) and turns previously non-CAFFY things into CAFFY.

Fixes #17648
Fixes #9718

Evaluation
==========

NoFib
-----

Boot with: `make boot mode=fast`
Run: `make mode=fast EXTRA_RUNTEST_OPTS="-cachegrind" NoFibRuns=1`

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             FS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
              S          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             VS          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            VSD          -0.0%      0.0%     -0.0%     -0.0%     -0.5%
            VSM          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           anna          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           ansi          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           atom          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         awards          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         banner          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     bernouilli          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   binary-trees          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         boyer2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           bspt          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      cacheprof          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       calendar          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       cichelli          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        circsim          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       clausify          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
  comp_lab_zift          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       compress          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      compress2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            cse          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          eliza          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          event          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         exp3_8          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         expert          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 fannkuch-redux          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          fasta          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fem          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            fft          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           fft2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           fish          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          fluid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         fulsom          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         gamteb          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            gcd          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
    gen_regexps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         genfft          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
             gg          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           grep          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         hidden          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            hpg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            ida          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          infer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        integer          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   k-nucleotide          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        knights          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         lambda          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     last-piece          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           life          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lift          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         linear          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      listcompr          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         mandel          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        mandel2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           mate          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        minimax          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        mkhprog          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     multiplier          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         n-body          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       nucleic2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           para          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      paraffins          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         parser          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        parstof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            pic          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       pidigits          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         pretty          -0.0%      0.0%     -0.3%     -0.4%     -0.4%
         primes          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      primetest          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         prolog          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         puzzle          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         queens          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        reptile          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
reverse-complem          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           rfib          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            rsa          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            scc          -0.0%      0.0%     -0.3%     -0.5%     -0.4%
          sched          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            scs          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         simple          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          solid          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        sorting          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
  spectral-norm          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
         symalg          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
            tak          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      transform          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       treejoin          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      typecheck          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
        veritas          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           wang          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
      wave4main          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve2          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           x2n1          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.3%     -0.5%     -0.5%
            Max          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 Geometric Mean          -0.0%     -0.0%     -0.0%     -0.0%     -0.0%

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
        circsim          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
       gc_bench          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           hash          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
     spellcheck          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            Max          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
 Geometric Mean          -0.0%     +0.0%     -0.0%     -0.0%     -0.0%

Manual inspection of programs in testsuite/tests/programs
---------------------------------------------------------

I built these programs with a bunch of dump flags and `-O` and compared
STG, Cmm, and Asm dumps and file sizes.

(Below the numbers in parenthesis show number of modules in the program)

These programs have identical compiler (same .hi and .o sizes, STG, and
Cmm and Asm dumps):

- Queens (1), andre_monad (1), cholewo-eval (2), cvh_unboxing (3),
  andy_cherry (7), fun_insts (1), hs-boot (4), fast2haskell (2),
  jl_defaults (1), jq_readsPrec (1), jules_xref (1), jtod_circint (4),
  jules_xref2 (1), lennart_range (1), lex (1), life_space_leak (1),
  bargon-mangler-bug (7), record_upd (1), rittri (1), sanders_array (1),
  strict_anns (1), thurston-module-arith (2), okeefe_neural (1),
  joao-circular (6), 10queens (1)

Programs with different compiler outputs:

- jl_defaults (1): For some reason GHC HEAD marks a lot of top-level
  `[Int]` closures as CAFFY for no reason. With this patch we no longer
  make them CAFFY and generate less SRT entries. For some reason Main.o
  is slightly larger with this patch (1.3%) and the executable sizes are
  the same. (I'd expect both to be smaller)

- launchbury (1): Same as jl_defaults: top-level `[Int]` closures marked
  as CAFFY for no reason. Similarly `Main.o` is 1.4% larger but the
  executable sizes are the same.

- galois_raytrace (13): Differences are in the Parse module. There are a
  lot, but some of the changes are caused by the fact that for some
  reason (I think a bug) GHC HEAD marks the dictionary for `Functor
  Identity` as CAFFY. Parse.o is 0.4% larger, the executable size is the
  same.

- north_array: We now generate less SRT entries because some of array
  primops used in this program like `NewArrayOp` get eliminated during
  Stg-to-Cmm and turn some CAFFY things into non-CAFFY. Main.o gets 24%
  larger (9224 bytes from 9000 bytes), executable sizes are the same.

- seward-space-leak: Difference in this program is better shown by this
  smaller example:

      module Lib where

      data CDS
        = Case [CDS] [(Int, CDS)]
        | Call CDS CDS

      instance Eq CDS where
        Case sels1 rets1 == Case sels2 rets2 =
            sels1 == sels2 && rets1 == rets2
        Call a1 b1 == Call a2 b2 =
            a1 == a2 && b1 == b2
        _ == _ =
            False

   In this program GHC HEAD builds a new SRT for the recursive group of
   `(==)`, `(/=)` and the dictionary closure. Then `/=` points to `==`
   in its SRT field, and `==` uses the SRT object as its SRT. With this
   patch we use the closure for `/=` as the SRT and add `==` there. Then
   `/=` gets an empty SRT field and `==` points to `/=` in its SRT
   field.

   This change looks fine to me.

   Main.o gets 0.07% larger, executable sizes are identical.

head.hackage
------------

head.hackage's CI script builds 428 packages from Hackage using this
patch with no failures.

Compiler performance
--------------------

The compiler perf tests report that the compiler allocates slightly more
(worst case observed so far is 4%). However most programs in the test
suite are small, single file programs. To benchmark compiler performance
on something more realistic I build Cabal (the library, 236 modules)
with different optimisation levels. For the "max residency" row I run
GHC with `+RTS -s -A100k -i0 -h` for more accurate numbers. Other rows
are generated with just `-s`. (This is because `-i0` causes running GC
much more frequently and as a result "bytes copied" gets inflated by
more than 25x in some cases)

* -O0

|                 | GHC HEAD       | This MR        | Diff   |
| --------------- | -------------- | -------------- | ------ |
| Bytes allocated | 54,413,350,872 | 54,701,099,464 | +0.52% |
| Bytes copied    |  4,926,037,184 |  4,990,638,760 | +1.31% |
| Max residency   |    421,225,624 |    424,324,264 | +0.73% |

* -O1

|                 | GHC HEAD        | This MR         | Diff   |
| --------------- | --------------- | --------------- | ------ |
| Bytes allocated | 245,849,209,992 | 246,562,088,672 | +0.28% |
| Bytes copied    |  26,943,452,560 |  27,089,972,296 | +0.54% |
| Max residency   |     982,643,440 |     991,663,432 | +0.91% |

* -O2

|                 | GHC HEAD        | This MR         | Diff   |
| --------------- | --------------- | --------------- | ------ |
| Bytes allocated | 291,044,511,408 | 291,863,910,912 | +0.28% |
| Bytes copied    |  37,044,237,616 |  36,121,690,472 | -2.49% |
| Max residency   |   1,071,600,328 |   1,086,396,256 | +1.38% |

Extra compiler allocations
--------------------------

Runtime allocations of programs are as reported above (NoFib section).

The compiler now allocates more than before. Main source of allocation
in this patch compared to base commit is the new SRT algorithm
(GHC.Cmm.Info.Build). Below is some of the extra work we do with this
patch, numbers generated by profiled stage 2 compiler when building a
pathological case (the test 'ManyConstructors') with '-O2':

- We now sort the final STG for a module, which means traversing the
  entire program, generating free variable set for each top-level
  binding, doing SCC analysis, and re-ordering the program. In
  ManyConstructors this step allocates 97,889,952 bytes.

- We now do SRT analysis on static data, which in a program like
  ManyConstructors causes analysing 10,000 bindings that we would
  previously just skip. This step allocates 70,898,352 bytes.

- We now maintain an SRT map for the entire module as we compile Cmm
  groups:

      data ModuleSRTInfo = ModuleSRTInfo
        { ...
        , moduleSRTMap :: SRTMap
        }

   (SRTMap is just a strict Map from the 'containers' library)

   This map gets an entry for most bindings in a module (exceptions are
   THUNKs and CAFFY static functions). For ManyConstructors this map
   gets 50015 entries.

- Once we're done with code generation we generate a NameSet from SRTMap
  for the non-CAFFY names in the current module. This set gets the same
  number of entries as the SRTMap.

- Finally we update CafInfos in ModDetails for the non-CAFFY Ids, using
  the NameSet generated in the previous step. This usually does the
  least amount of allocation among the work listed here.

Only place with this patch where we do less work in the CAF analysis in
the tidying pass (CoreTidy). However that doesn't save us much, as the
pass still needs to traverse the whole program and update IdInfos for
other reasons. Only thing we don't here do is the `hasCafRefs` pass over
the RHS of bindings, which is a stateless pass that returns a boolean
value, so it doesn't allocate much.

(Metric changes blow are all increased allocations)

Metric changes
--------------

Metric Increase:
    ManyAlternatives
    ManyConstructors
    T13035
    T14683
    T1969
    T9961

- - - - -
2a87a565 by Andreas Klebinger at 2020-01-31T12:21:10+03:00
A few optimizations in STG and Cmm parts:

(Guided by the profiler output)

- Add a few bang patterns, INLINABLE annotations, and a seqList in a few
  places in Cmm and STG parts.

- Do not add external variables as dependencies in STG dependency
  analysis (GHC.Stg.DepAnal).

- - - - -
bef704b6 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Improve skolemisation

This patch avoids skolemiseUnboundMetaTyVar making
up a fresh Name when it doesn't need to.

See Note [Skolemising and identity]

Improves error messsages for partial type signatures.

- - - - -
cd110423 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Improve pretty-printing for TyConBinders

In particular, show their kinds.

- - - - -
913287a0 by Simon Peyton Jones at 2020-02-01T02:28:45-05:00
Fix scoping of TyCon binders in TcTyClsDecls

This patch fixes #17566 by refactoring the way we decide the final
identity of the tyvars in the TyCons of a possibly-recursive nest
of type and class decls, possibly with associated types.

It's all laid out in
  Note [Swizzling the tyvars before generaliseTcTyCon]

Main changes:

* We have to generalise each decl (with its associated types)
  all at once: TcTyClsDecls.generaliseTyClDecl

* The main new work is done in TcTyClsDecls.swizzleTcTyConBndrs

* The mysterious TcHsSyn.zonkRecTyVarBndrs dies altogether

Other smaller things:

* A little refactoring, moving bindTyClTyVars from tcTyClDecl1
  to tcDataDefn, tcSynRhs, etc.  Clearer, reduces the number of
  parameters

* Reduce the amount of swizzling required.
  Specifically, bindExplicitTKBndrs_Q_Tv doesn't need
    to clone a new Name for the TyVarTv, and not
    cloning means that in the vasly common case,
    swizzleTyConBndrs is a no-op

  In detail:
    Rename newTyVarTyVar --> cloneTyVarTyVar
    Add newTyVarTyTyVar that doesn't clone
    Use the non-cloning newTyVarTyVar in
       bindExplicitTKBndrs_Q_Tv
       Rename newFlexiKindedTyVarTyVar
           --> cloneFlexiKindedTyVarTyVar

* Define new utility function and use it
     HsDecls.familyDeclName ::
        FamilyDecl (GhcPass p) -> IdP (GhcPass p)

Updates haddock submodule.

- - - - -
58ed6c4a by Ben Gamari at 2020-02-01T02:29:23-05:00
rts/M32Alloc: Don't attempt to unmap non-existent pages

The m32 allocator's `pages` list may contain NULLs in the case that the
page was flushed. Some `munmap` implementations (e.g. FreeBSD's) don't
like it if we pass them NULL. Don't do that.

- - - - -
859db7d6 by Ömer Sinan Ağacan at 2020-02-01T14:18:49+03:00
Improve/fix -fcatch-bottoms documentation

Old documentation suggests that -fcatch-bottoms only adds a default
alternative to bottoming case expression, but that's not true. We use a
very simplistic "is exhaustive" check and add default alternatives to
any case expression that does not cover all constructors of the type. In
case of GADTs this simple check assumes all constructors should be
covered, even the ones ruled out by the type of the scrutinee.

Update the documentation to reflect this.

(Originally noticed in #17648)

[ci skip]

- - - - -
54dfa94a by John Ericson at 2020-02-03T21:14:24-05:00
Fix docs for FrontendResult

Other variant was removed in ac1a379363618a6f2f17fff65ce9129164b6ef30
but docs were no changed.

- - - - -
5e63d9c0 by John Ericson at 2020-02-03T21:15:02-05:00
Refactor HscMain.finish

I found the old control flow a bit hard to follow; I rewrote it to first
decide whether to desugar, and then use that choice when computing
whether to simplify / what sort of interface file to write.

I hope eventually we will always write post-tc interface files, which
will make the logic of this function even simpler, and continue the
thrust of this refactor.

- - - - -
e580e5b8 by Stefan Schulze Frielinghaus at 2020-02-04T09:29:00-05:00
Do not build StgCRunAsm.S for unregisterised builds

For unregisterised builds StgRun/StgReturn are implemented via a mini
interpreter in StgCRun.c and therefore would collide with the
implementations in StgCRunAsm.S.

- - - - -
e3b0bd97 by Stefan Schulze Frielinghaus at 2020-02-04T09:29:00-05:00
fixup! fixup! Do not build StgCRunAsm.S for unregisterised builds

- - - - -
eb629fab by John Ericson at 2020-02-04T09:29:38-05:00
Delete some superfluous helper functions in HscMain

The driver code is some of the nastiest in GHC, and I am worried about
being able to untangle all the tech debt. In `HscMain` we have a number
of helpers which are either not-used or little used. I delete them so we
can reduce cognative load, distilling the essential complexity away from
the cruft.

- - - - -
c90eca55 by Sebastian Graf at 2020-02-05T09:21:29-05:00
PmCheck: Record type constraints arising from existentials in `PmCoreCt`s

In #17703 (a follow-up of !2192), we established that contrary to my
belief, type constraints arising from existentials in code like

```hs
data Ex where Ex :: a -> Ex
f _ | let x = Ex @Int 15 = case x of Ex -> ...
```

are in fact useful.

This commit makes a number of refactorings and improvements to comments,
but fundamentally changes `addCoreCt.core_expr` to record the type
constraint `a ~ Int` in addition to `x ~ Ex @a y` and `y ~ 15`.

Fixes #17703.

- - - - -
6d3b5d57 by Ömer Sinan Ağacan at 2020-02-05T09:22:10-05:00
testlib: Extend existing *_opts in extra_*_opts

Previously we'd override the existing {run,hc} opts in
extra_{run,hc}_opts, which caused flakiness in T1969, see #17712.

extra_{run,hc}_opts now extends {run,hc} opts, instead of overriding.

Also we shrank the allocation area for T1969 in order to increase
residency sampling frequency.

Fixes #17712

- - - - -
9c89a48d by Ömer Sinan Ağacan at 2020-02-05T09:22:52-05:00
Remove CafInfo-related code from STG lambda lift pass

After c846618ae0 we don't have accurate CafInfos for Ids in the current
module and we're free to introduce new CAFFY or non-CAFFY bindings or
change CafInfos of existing binders; so no we no longer need to
maintain CafInfos in Core or STG passes.

- - - - -
70ddb8bf by Ryan Scott at 2020-02-05T09:23:30-05:00
Add regression test for #17773

- - - - -
e8004e5d by Ben Gamari at 2020-02-05T13:55:19-05:00
gitlab-ci: Allow Windows builds to fail again

Due to T7702 and the process issues described in #17777.
- - - - -
29b72c00 by Ben Gamari at 2020-02-06T11:55:41-05:00
VarSet: Introduce nonDetFoldVarSet

- - - - -
c4e6b35d by Ben Gamari at 2020-02-06T11:55:41-05:00
Move closeOverKinds and friends to TyCoFVs

- - - - -
ed2f0e5c by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Reform the free variable finders for types

This patch delivers on (much of) #17509.

* Introduces the shallow vs deep free variable distinction

* Introduce TyCoRep.foldType,
    foldType :: Monoid a => TyCoFolder env a
                         -> env -> Type -> a
  and use it in the free variable finders.

* Substitution in TyCoSubst
   * ASSERTs are on for checkValidSubst
   * checkValidSubst uses shallowTyCoVarsOfTypes etc

Quite a few things still to do

* We could use foldType in lots of other places

* We could use mapType for substitution.  (Check that we get
  good code!)

* Some (but not yet all) clients of substitution can now
  save time by using shallowTyCoVarsOfTypes

* All calls to tyCoVarsOfTypes should be inspected; most of
  them should be shallow.  Maybe.

* Currently shallowTyCoVarsOfTypes still returns
  unification variables, but not CoVarHoles.
  Reason: we need to return unification variables
  in some of the calls in TcSimplify, eg when promoting.

* We should do the same thing for tyCoFVsOfTypes, which is
  currently unchanged.

* tyCoFVsOfTypes returns CoVarHoles, because of the
  use in TcSimplify.mkResidualConstraints.  See
  Note [Emitting the residual implication in simplifyInfer]

* #17509 talks about "relevant" variables too.

- - - - -
01a1f4fb by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for noFreeVarsOfType

- - - - -
0e59afd6 by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Simplify closeOverKinds

- - - - -
9ca5c88e by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for coVarsOfType

- - - - -
5541b87c by Simon Peyton Jones at 2020-02-06T11:55:41-05:00
Use foldTyCo for exactTyCoVarsOfType

This entailed

* Adding a tcf_view field to TyCoFolder

* Moving exactTyCoVarsOtType to TcType.  It properly belongs
  there, since only the typechecker calls this function. But
  it also means that we can "see" and inline tcView.

Metric Decrease:
  T14683

- - - - -
7c122851 by Simon Peyton Jones at 2020-02-06T11:56:02-05:00
Comments only

- - - - -
588acb99 by Adam Sandberg Eriksson at 2020-02-08T10:15:38-05:00
slightly better named cost-centres for simple pattern bindings #17006

```
main = do
  print $ g [1..100] a
  where g xs x   = map (`mod` x) xs
        a :: Int = 324
```

The above program previously attributed the cost of computing 324 to a cost
centre named `(...)`, with this change the cost is attributed to `a` instead.

This change only affects simple pattern bindings (decorated variables: type
signatures, parens, ~ annotations and ! annotations).

- - - - -
309f8cfd by Richard Eisenberg at 2020-02-08T10:16:33-05:00
Remove unnecessary parentheses

- - - - -
7755ffc2 by Richard Eisenberg at 2020-02-08T10:16:33-05:00
Introduce IsPass; refactor wrappers.

There are two main payloads of this patch:

1. This introduces IsPass, which allows e.g. printing
   code to ask what pass it is running in (Renamed vs
   Typechecked) and thus print extension fields. See
   Note [IsPass] in Hs.Extension

2. This moves the HsWrap constructor into an extension
   field, where it rightly belongs. This is done for
   HsExpr and HsCmd, but not for HsPat, which is left
   as an exercise for the reader.

There is also some refactoring around SyntaxExprs, but this
is really just incidental.

This patch subsumes !1721 (sorry @chreekat).

Along the way, there is a bit of refactoring in GHC.Hs.Extension,
including the removal of NameOrRdrName in favor of NoGhcTc.
This meant that we had no real need for GHC.Hs.PlaceHolder, so
I got rid of it.

Updates haddock submodule.

-------------------------
Metric Decrease:
    haddock.compiler
-------------------------

- - - - -
7d452be4 by Dylan Yudaken at 2020-02-08T10:17:17-05:00
Fix hs_try_putmvar losing track of running cap

If hs_try_putmvar was called through an unsafe import, it would lose track of the running cap causing a deadlock

- - - - -
c2e301ae by Ben Gamari at 2020-02-08T10:17:55-05:00
compiler: Qualify imports of Data.List

- - - - -
aede171a by Ben Gamari at 2020-02-08T10:17:55-05:00
testsuite: Fix -Wcompat-unqualified-imports issues

- - - - -
4435a8e0 by Ben Gamari at 2020-02-08T10:17:55-05:00
Introduce -Wcompat-unqualified-imports

This implements the warning proposed in option (B) of the
Data.List.singleton CLC [discussion][].
This warning, which is included in `-Wcompat` is intended to help users
identify imports of modules that will change incompatibly in future GHC
releases. This currently only includes `Data.List` due to the expected
specialisation and addition of `Data.List.singleton`.

Fixes #17244.

[discussion]: https://groups.google.com/d/msg/haskell-core-libraries/q3zHLmzBa5E/PmlAs_kYAQAJ

- - - - -
28b5349a by Ben Gamari at 2020-02-08T10:17:55-05:00
Bump stm and process submodules

- - - - -
7d04b9f2 by Ben Gamari at 2020-02-08T10:18:31-05:00
hadrian: Allow override of Cabal configuration in hadrian.settings

Fixes #17612 by adding a `cabal.configure.opts` key for
`hadrian.settings`.

- - - - -
88bf81aa by Andreas Klebinger at 2020-02-08T10:19:10-05:00
Optimize unpackCString# to allocate less.

unpackCString# is a recursive function which for each iteration
returns a Cons cell containing the current Char, and a thunk for
unpacking the rest of the string.

In this patch we change from storing addr + offset inside this thunk
to storing only the addr, simply incrementing the address on each
iteration.

This saves one word of allocation per unpacked character.
For a program like "main = print "<largishString>" this amounts
to 2-3% fewer % in bytes allocated.

I also removed the now redundant local unpack definitions.
This removes one call per unpack operation.

- - - - -
bec76733 by Ben Gamari at 2020-02-08T10:19:57-05:00
Fix GhcThreaded setting

This adopts a patch from NetBSD's packaging fixing the `GhcThreaded`
option of the make build system. In addition we introduce a `ghcThreaded`
option in hadrian's `Flavour` type.

Also fix Hadrian's treatment of the `Use Threaded` entry in `settings`.
Previously it would incorrectly claim `Use Threaded = True` if we were
building the `threaded` runtime way. However, this is inconsistent with
the `make` build system, which defines it to be whether the `ghc`
executable is linked against the threaded runtime.

Fixes #17692.

- - - - -
545cf1e1 by Ben Gamari at 2020-02-08T10:20:37-05:00
hadrian: Depend upon libray dependencies when configuring packages

This will hopefully fix #17631.

- - - - -
047d3d75 by Ben Gamari at 2020-02-08T10:21:16-05:00
testsuite: Add test for #15316

This is the full testcase for T15316.

- - - - -
768e5866 by Julien Debon at 2020-02-08T10:22:07-05:00
doc(Data.List): Add some examples to Data.List

- - - - -
3900cb83 by Julien Debon at 2020-02-08T10:22:07-05:00
Apply suggestion to libraries/base/GHC/List.hs
- - - - -
bd666766 by Ben Gamari at 2020-02-08T10:22:45-05:00
users-guide: Clarify that bundled patsyns were introduced in GHC 8.0

Closes #17094.

- - - - -
95741ea1 by Pepe Iborra at 2020-02-08T10:23:23-05:00
Update to hie-bios 0.3.2 style program cradle

- - - - -
fb5c1912 by Sylvain Henry at 2020-02-08T10:24:07-05:00
Remove redundant case

This alternative is redundant and triggers no warning when building with 8.6.5

- - - - -
5d83d948 by Matthew Pickering at 2020-02-08T10:24:43-05:00
Add mkHieFileWithSource which doesn't read the source file from disk

cc/ @pepeiborra

- - - - -
dfdae56d by Andreas Klebinger at 2020-02-08T10:25:20-05:00
Rename ghcAssert to stgAssert in hp2ps/Main.h.

This fixes #17763
- - - - -
658f7ac6 by Ben Gamari at 2020-02-08T10:26:00-05:00
includes: Avoid using single-line comments in HsFFI.h

While single-line comments are supported by C99, dtrace on SmartOS
apparently doesn't support them yet.

- - - - -
c95920a6 by Ömer Sinan Ağacan at 2020-02-08T10:26:42-05:00
Import qualified Prelude in parser

This is in preparation of backwards-incompatible changes in happy.
See https://github.com/simonmar/happy/issues/166

- - - - -
b6dc319a by Ömer Sinan Ağacan at 2020-02-08T10:27:23-05:00
Add regression test for #12760

The bug seems to be fixed in the meantime, make sure it stays fixed.

Closes #12760

- - - - -
b3857b62 by Ben Gamari at 2020-02-08T10:28:03-05:00
base: Drop out-of-date comment

The comment in GHC.Base claimed that ($) couldn't be used in that module
as it was wired-in. However, this is no longer true; ($) is merely known
key and is defined in Haskell (with a RuntimeRep-polymorphic type) in
GHC.Base.

The one piece of magic that ($) retains is that it a special typing
rule to allow type inference with higher-rank types
(e.g. `runST $ blah`; see Note [Typing rule for ($)] in TcExpr).

- - - - -
1183ae94 by Daniel Gröber at 2020-02-08T10:29:00-05:00
rts: Fix Arena blocks accounting for MBlock sized allocations

When requesting more than BLOCKS_PER_MBLOCK blocks allocGroup can return a
different number of blocks than requested. Here we use the number of
requested blocks, however arenaFree will subtract the actual number of
blocks we got from arena_blocks (possibly) resulting in a negative value
and triggering ASSERT(arena_blocks >= 0).

- - - - -
97d59db5 by Daniel Gröber at 2020-02-08T10:29:48-05:00
rts: Fix need_prealloc being reset when retainer profiling is on

- - - - -
1f630025 by Krzysztof Gogolewski at 2020-02-09T02:52:27-05:00
Add a test for #15712

- - - - -
2ac784ab by Ben Gamari at 2020-02-09T02:53:05-05:00
hadrian: Add --test-metrics argument

Allowing the test metric output to be captured to a file, a la
the METRIC_FILE environment variable of the make build system.

- - - - -
f432d8c6 by Ben Gamari at 2020-02-09T02:53:05-05:00
hadrian: Fix --test-summary argument

This appears to be a cut-and-paste error.

- - - - -
a906595f by Arnaud Spiwack at 2020-02-09T02:53:50-05:00
Fix an outdated note link

This link appears to have been forgotten in
0dad81ca5fd1f63bf8a3b6ad09787559e8bd05c0 .

- - - - -
3ae83da1 by Alp Mestanogullari at 2020-02-09T02:54:28-05:00
hadrian: Windows fixes (bindists, CI)

This commit implements a few Windows-specific fixes which get us from a CI
job that can't even get as far as starting the testsuite driver, to a state
where we can run the entire testssuite (but have test failures to fix).

- Don't forget about a potential extension for the haddock program, when
  preparing the bindist.
- Build the timeout program, used by the testsuite driver on Windows in place
  of the Python script used elsewhere, using the boot compiler. We could
  alternatively build it with the compiler that we're going to test but this
  would be a lot more tedious to write.
- Implement a wrapper-script less installation procedure for Windows, in
  `hadrian/bindist/Makefile.
- Make dependencies a bit more accurate in the aforementioned Makefile.
- Update Windows/Hadrian CI job accordingly.

This patch fixes #17486.

- - - - -
82f9be8c by Roland Senn at 2020-02-09T02:55:06-05:00
Fix #14628: Panic (No skolem Info) in GHCi

This patch implements the [sugggestion from Simon (PJ)](https://gitlab.haskell.org/ghc/ghc/issues/14628#note_146559):
- Make `TcErrors.getSkolemInfo` return a `SkolemInfo` rather than an `Implication`.
- If `getSkolemInfo` gets `RuntimeUnk`s, just return a new data constructor in `SkolemInfo`, called `RuntimeUnkSkol`.
- In `TcErrors.pprSkols` print something sensible for a `RuntimeUnkSkol`.

The `getSkolemInfo` function paniced while formating suggestions to add type annotations (subfunction `suggestAddSig`)
to a *"Couldn't match type ‘x’ with ‘y’"* error message.
The `getSkolemInfo` function didn't find any Implication value and paniced.
With this patch the `getSkolemInfo` function does no longer panic, if it finds `RuntimeUnkSkol`s.

As the panic occured while processing an error message, we don't need to implement any new error message!

- - - - -
b2e18e26 by Andreas Klebinger at 2020-02-09T02:55:46-05:00
Fix -ddump-stg-final.

Once again make sure this dumps the STG used for codegen.

- - - - -
414e2f62 by Sylvain Henry at 2020-02-09T02:56:26-05:00
Force -fPIC for intree GMP (fix #17799)

Configure intree GMP with `--with-pic` instead of patching it. Moreover
the correct patching was only done for x86_64/darwin (see #17799).

- - - - -
f0fd72ee by Sebastian Graf at 2020-02-09T17:22:38-05:00
8.10 Release notes for improvements to the pattern-match checker [skip ci]

A little late to the game, but better late than never.

- - - - -
00dc0f7e by Ömer Sinan Ağacan at 2020-02-09T17:23:17-05:00
Add regression test for #13142

Closes #13142

- - - - -
f3e737bb by Sebastian Graf at 2020-02-10T20:04:09-05:00
Fix long distance info for record updates

For record updates where the `record_expr` is a variable, as in #17783:

```hs
data PartialRec = No
                | Yes { a :: Int, b :: Bool }
update No = No
update r@(Yes {}) = r { b = False }
```

We should make use of long distance info in
`-Wincomplete-record-updates` checking. But the call to `matchWrapper`
in the `RecUpd` case didn't specify a scrutinee expression, which would
correspond to the `record_expr` `r` here. That is fixed now.

Fixes #17783.

- - - - -
5670881d by Tamar Christina at 2020-02-10T20:05:04-05:00
Fs: Fix UNC remapping code.

- - - - -
375b3c45 by Oleg Grenrus at 2020-02-11T05:07:30-05:00
Add singleton to Data.OldList

- - - - -
de32beff by Richard Eisenberg at 2020-02-11T05:08:10-05:00
Do not create nested quantified constraints

Previously, we would accidentally make constraints like
forall a. C a => forall b. D b => E a b c as we traversed
superclasses. No longer!

This patch also expands Note [Eagerly expand given superclasses]
to work over quantified constraints; necessary for T16502b.

Close #17202 and #16502.

test cases: typecheck/should_compile/T{17202,16502{,b}}

- - - - -
e319570e by Ben Gamari at 2020-02-11T05:08:47-05:00
rts: Use nanosleep instead of usleep

usleep was removed in POSIX.1-2008.

- - - - -
b75e7486 by Ben Gamari at 2020-02-11T05:09:24-05:00
rts: Remove incorrect assertions around MSG_THROWTO messages

Previously we would assert that threads which are sending a
`MSG_THROWTO` message must have their blocking status be blocked on the
message. In the usual case of a thread throwing to another thread this
is guaranteed by `stg_killThreadzh`.  However, `throwToSelf`, used by
the GC to kill threads which ran out of heap, failed to guarantee this.

Noted while debugging #17785.

- - - - -
aba51b65 by Sylvain Henry at 2020-02-11T05:10:04-05:00
Add arithmetic exception primops (#14664)

- - - - -
b157399f by Ben Gamari at 2020-02-11T05:10:40-05:00
configure: Don't assume Gnu linker on Solaris

Compl Yue noticed that the linker was dumping the link map on SmartOS. This is
because Smartos uses the Solaris linker, which uses the `-64` flag, not
`-m64` like Gnu ld, to indicate that it should link for 64-bits. Fix the
configure script to handle the Solaris linker correctly.

- - - - -
d8d73d77 by Simon Peyton Jones at 2020-02-11T05:11:18-05:00
Notes only: telescopes

This documentation-only patch fixes #17793

- - - - -
58a4ddef by Alp Mestanogullari at 2020-02-11T05:12:17-05:00
hadrian: build (and ship) iserv on Windows

- - - - -
82023524 by Matthew Pickering at 2020-02-11T18:04:17-05:00
TemplateHaskellQuotes: Allow nested splices

There is no issue with nested splices as they do not require any compile
time code execution. All execution is delayed until the top-level
splice.

- - - - -
50e24edd by Ömer Sinan Ağacan at 2020-02-11T18:04:57-05:00
Remove Hadrian's copy of (Data.Functor.<&>)

The function was added to base with base-4.11 (GHC 8.4)

- - - - -
f82a2f90 by Sylvain Henry at 2020-02-12T01:56:46-05:00
Document GMP build [skip ci]

- - - - -
da7f7479 by Sylvain Henry at 2020-02-12T01:57:27-05:00
Module hierarchy: ByteCode and Runtime (cf #13009)

Update haddock submodule

- - - - -
04f51297 by Ömer Sinan Ağacan at 2020-02-12T01:58:11-05:00
Fix naming of tests for #12923

- - - - -
31fc3321 by Ömer Sinan Ağacan at 2020-02-12T01:58:11-05:00
Add regression test for #12926

Closes #12926

- - - - -
f0c0ee7d by Krzysztof Gogolewski at 2020-02-12T01:58:51-05:00
Fix order of arguments in specializer (#17801)

See https://gitlab.haskell.org/ghc/ghc/issues/17801#note_253330

No regression test, as it's hard to trigger.

- - - - -
059c3c9d by Sebastian Graf at 2020-02-12T11:00:58+01:00
Separate CPR analysis from the Demand analyser

The reasons for that can be found in the wiki:
https://gitlab.haskell.org/ghc/ghc/wikis/nested-cpr/split-off-cpr

We now run CPR after demand analysis (except for after the final demand
analysis run just before code gen). CPR got its own dump flags
(`-ddump-cpr-anal`, `-ddump-cpr-signatures`), but not its own flag to
activate/deactivate. It will run with `-fstrictness`/`-fworker-wrapper`.

As explained on the wiki page, this step is necessary for a sane Nested
CPR analysis. And it has quite positive impact on compiler performance:

Metric Decrease:
    T9233
    T9675
    T9961
    T15263

- - - - -
f5ffd8d9 by Ben Gamari at 2020-02-12T17:22:37-05:00
base: Expose GHC.Unicode.unicodeVersion

This exposes a Data.Version.Version representing the version of the
Unicode database used by `base`. This should clear up some confusion I
have seen in tickets regarding with which Unicode versions a given GHC
can be expected to work.

While in town I also regenerated (but did not update) the Unicode
database with database 12.0.0. Strangely, the file cited in the README
no longer existed. Consequently, I used
https://www.unicode.org/Public/12.0.0/ucd/UnicodeData.txt and was
slightly surprised to find that there were a few changes.

- - - - -
6c2585e0 by Ben Gamari at 2020-02-12T17:22:37-05:00
base: Update Unicode database to 12.1.0

Using `curl https://www.unicode.org/Public/12.1.0/ucd/UnicodeData.txt |
libraries/base/cbits/ubconfc 12.1.0`.

- - - - -
df084681 by Krzysztof Gogolewski at 2020-02-12T23:58:52+01:00
Always display inferred variables using braces

We now always show "forall {a}. T" for inferred variables,
previously this was controlled by -fprint-explicit-foralls.

This implements part 1 of https://github.com/ghc-proposals/ghc-proposals/pull/179.

Part of GHC ticket #16320.

Furthermore, when printing a levity restriction error, we now display
the HsWrap of the expression. This lets users see the full elaboration with
-fprint-typechecker-elaboration (see also #17670)

- - - - -
16d643cf by Sylvain Henry at 2020-02-13T09:16:04-05:00
Remove -ddump-srts flag

This flag is deemed not useful.

- - - - -
fa28ae95 by Sylvain Henry at 2020-02-13T09:16:04-05:00
Fix flag documentation (#17826)

- - - - -
1bfd8259 by Sylvain Henry at 2020-02-13T09:16:43-05:00
Ensure that Hadrian is built correctly before using it

When Hadrian failed to build, the script would pick a previously built
Hadrian (if available) instead of failing.

- - - - -
cd6e786a by Ömer Sinan Ağacan at 2020-02-14T05:29:56-05:00
Add test for #17648

- - - - -
9f2c3677 by Sylvain Henry at 2020-02-14T05:30:39-05:00
GMP expects the Target platform as --host parameter

- - - - -
aa6086fd by Oleg Grenrus at 2020-02-14T05:31:16-05:00
Add explicit LANGUAGE Safe to template-haskell


(cherry picked from commit a5e0f376821ca882880b03b07b451aa574e289ec)
- - - - -
af6a0c36 by Ben Gamari at 2020-02-14T05:31:53-05:00
hadrian: Add execution and target architecture to stage-compilation figure

- - - - -
cf739945 by Sylvain Henry at 2020-02-14T05:32:37-05:00
Module hierarchy: HsToCore (cf #13009)

- - - - -
719db318 by Simon Peyton Jones at 2020-02-14T05:33:16-05:00
De-duplicate overlapping Notes

Documentation only.  Fixes #17827

- - - - -
7550417a by Sylvain Henry at 2020-02-14T05:33:56-05:00
Hadrian: drop Sphinx flag checking for PDF documentation (#17825)

It seems that Sphinx produces the ghc-flags.txt in
doc/users_guide/_build rather than pdfRoot. We could copy ghc-flags.txt
into pdfRoot (like happens naturally in the HTML case) but the benefit
is pretty small. Let's just only check the HTML case.

- - - - -
813842f4 by Ben Gamari at 2020-02-14T10:16:36-05:00
make: Be more selective in building windows-extra-src tarball

- - - - -
0725f4bb by Ben Gamari at 2020-02-14T10:16:36-05:00
Rework handling of win32 toolchain tarballs

- - - - -
565ce7ae by Ben Gamari at 2020-02-14T10:16:36-05:00
gitlab-ci: Consolidate CI logic

This moves nearly all of the CI logic to .gitlab/ci.sh. This improves
things in a number of ways:

 * it's harder for inconsistencies to arise between architectures
 * it's easier to share logic between architectures
 * on Windows, it's easier to ensure that all CI steps are executed from
   within a properly initialized mingw session.

While in town I also add a FreeBSD build job and update the Windows job
to use the gitlab-runner PowerShell executor, since cmd.exe will be
deprecated soon (fixing #17699).

- - - - -
9cbace74 by Ben Gamari at 2020-02-14T10:16:36-05:00
gitlab-ci: Deduplicate nightly job configuration

- - - - -
6e837144 by Ben Gamari at 2020-02-14T10:16:36-05:00
integer-gmp: Fix unused command-line argument

-L is only needed during linking.

- - - - -
e5ee07ab by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Don't ask sed to operate in-place on symlinks

Some sed implementations (e.g. FreeBSD) refuse to operate in-place on
symlinks.

- - - - -
71e5e68f by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Disable tests that assume name of libstdc++ on FreeBSD

- - - - -
7b2da0f4 by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite: Mark T6132 as broken on FreeBSD

- - - - -
8ef7a15a by Ben Gamari at 2020-02-14T10:16:36-05:00
testsuite/T16930: Don't rely on gnu grep specific --include

In BSD grep this flag only affects directory recursion.

- - - - -
6060003e by Ben Gamari at 2020-02-14T10:16:36-05:00
Pass -Wno-unused-command-line-arguments during link on FreeBSD

FreeBSD cc throws a warning if we pass -pthread without actually using
any pthread symbols.

- - - - -
97497bae by Ben Gamari at 2020-02-14T10:16:36-05:00
base: Always clamp reads/writes to 2GB in length

Previously we did this only on Darwin due to #17414. However, even on
other platforms >2GB writes are on shaky ground. POSIX explicitly says
that the result is implementation-specified and Linux will write at most
0x7ffff000, even on 64-bit platforms. Moreover, getting the sign
of the syscall result correct is tricky, as demonstrated by the fact
that T17414 currently fails on FreeBSD.

For simplicity we now just uniformly clamp to 0x7ffff000 on all
platforms.

- - - - -
49be2a3f by Ben Gamari at 2020-02-14T10:16:36-05:00
configure: Fix sphinx version test

The check for the "v" prefix is redundant.

- - - - -
f7f7a556 by Ben Gamari at 2020-02-14T10:16:37-05:00
users-guide: Fix unknown link targets

- - - - -
a204102c by Ben Gamari at 2020-02-14T10:16:37-05:00
docs/compare-flags: Don't use python f-strings

- - - - -
92e15a37 by Ben Gamari at 2020-02-14T10:16:37-05:00
gitlab-ci: Fix various shellcheck warnings

- - - - -
459f7c6e by Ben Gamari at 2020-02-14T10:16:37-05:00
hadrian: Drop empty arguments from target list

Fixes #17748.

- - - - -
c06df28d by Ben Gamari at 2020-02-14T10:16:37-05:00
users-guide: Fix "invalid file" failure

I have no idea how this worked previously. Different Python version?

- - - - -
3fe8444f by Ben Gamari at 2020-02-14T10:16:59-05:00
testsuite: Mark T7702 as fragile on Windows

Due to #16799. There was previously an attempt to mark it as broken but
the `opsys` name was incorrect.

- - - - -
fe02f781 by Ben Gamari at 2020-02-14T10:16:59-05:00
testsuite: Assert the opsys names are known

Previously opsys would take any string. This meant it was very easy for
a typo to silently render the predicate ineffective. Fix this by
checking the given operating system name against a list of known values.

- - - - -
149e2a3a by Ben Gamari at 2020-02-14T10:16:59-05:00
compare-flags: Don't rely on encoding flag of subprocess.check_output

Apparently it isn't supported by some slightly older Python versions.

- - - - -
798d59f6 by Ben Gamari at 2020-02-14T10:16:59-05:00
rts: Add more debug output to failed path in onIOComplete

This will help track down #17035.

- - - - -
e35f3f98 by Ben Gamari at 2020-02-14T10:16:59-05:00
gitlab-ci: Allow i386 Windows builds to fail again

Due to the resistance of #17736 to resolution.

- - - - -
261a3cf8 by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Build integer-simple job in the validate flavour

- - - - -
b613a961 by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Always use mingw64 python on Windows

- - - - -
1bc8c8cd by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Allow Windows build to fail due to #17777

The fact that `exec` isn't POSIX compliant means that things can break
in arbitrarily bad ways. Sometimes things happen to work correctly but
sadly this isn't always the case.

- - - - -
ac63020d by Ben Gamari at 2020-02-14T10:17:00-05:00
gitlab-ci: Drop unnecessary GHC_VERSION check

- - - - -
6926f369 by Ben Gamari at 2020-02-14T10:17:00-05:00
Bump process submodule

Folds in the second part of Phyx's Windows process exit fixes [1],
hopefully finally resolving issue #17480.

[1] https://github.com/haskell/process/pull/160

- - - - -
584eee71 by Tamar Christina at 2020-02-14T10:17:00-05:00
SysTools: Use "process job" when spawning processes on Windows

GHC should make calls using process jobs when calling out to GCC and LD.
The reason is these use the exec () family of posix functions.  Window's
process model doesn't allow replacement of processes so this is emulated
by creating a new process and immediately exiting the old one.  Because
of this when using normal Windows wait functions you would return even
without the child process having finished.  In this case if you are
depending on data from the child you will enter a race condition.

The usual fix for this is to use process jobs and wait for the
termination of all children that have ever been spawn by the process you
called. But also waiting for the freeing of all resources.

- - - - -
ecabfa28 by Tamar Christina at 2020-02-14T10:17:00-05:00
Revert "compiler: Disable atomic renaming on Windows"

The original reason this was disabled should be fixed by the previous
commit.

This reverts commit 1c1b63d63efe8b0f789aa7d5b87cfac3edd213eb.

- - - - -
06d60c66 by Ben Gamari at 2020-02-14T10:17:00-05:00
Bump Cabal submodule

- - - - -
8cabb384 by Ben Gamari at 2020-02-14T10:17:00-05:00
compare-flags: Fix output

- - - - -
8cf646d3 by Ben Gamari at 2020-02-14T10:17:00-05:00
users-guide: Document -ddump-srts

- - - - -
932307a5 by Ben Gamari at 2020-02-14T10:17:00-05:00
users-guide: Fix broken reference

- - - - -
e77818de by Ben Gamari at 2020-02-15T09:26:55-05:00
Accept performance changes

These manifested in the integer-simple job.

Metric Decrease:
    T12227
    T5549
    T14936
    T4830
    Conversions
    T5237
    T8766
    T4801
    T10359

Metric Increase:
    T12234
    T6048
    T3294
    T14683
    T3064
    T9872b
    T9872c
    T783
    T5837
    T10678
    T14697
    T5631
    T9203
    T13719
    T12707
    T13056
    T9630
    T10547
    T9872d
    T1969
    WWRec
    T10370
    T5321FD
    haddock.Cabal
    T5642
    T9872a
    T15263
    T12425
    MultiLayerModules
    T5205
    T9233
    T13379
    haddock.base
    T9020
    T13035
    T12150
    T9961

- - - - -
785008c1 by Ben Gamari at 2020-02-15T09:30:13-05:00
testsuite: Sort test names in expected change output

- - - - -
9e851472 by Ömer Sinan Ağacan at 2020-02-16T10:38:41+03:00
Revert "users-guide: Document -ddump-srts"

This reverts commit 8cf646d36b02b8ea1c289cb52781c9171853b514.

The flag was removed by 16d643cf.

[ci skip]

- - - - -
9792c816 by Ben Gamari at 2020-02-16T09:47:08-05:00
testsuite: Probe whether symlinks are usable on Windows

Closes #17706.

- - - - -
ee1e5342 by Vladislav Zavialov at 2020-02-16T09:47:44-05:00
Fix the "unused terminals: 2" warning in Parser.y

- - - - -
b4a8ce52 by Roland Senn at 2020-02-18T20:14:42-05:00
If a :reload finds syntax errors in the module graph, remove the loaded modules. (Fixes #17549)

The processing in `compiler/main/GhcMake.hs` computes the ModuleGraph. If it finds errors
in the module header or in the import specifications, then the new module graph is
incomplete and should not be used.
The code before #17549 just reported the errors and left the old ModuleGraph in place.
The new code of this MR replaces the old ModuleGraph with an empty one.

- - - - -
d7029cc0 by Sylvain Henry at 2020-02-18T20:15:30-05:00
Hadrian: refactor GMP in-tree build support (#17756)

* Hadrian doesn't use integer-gmp/config.mk file anymore to determine if
  building GMP in-tree is required.

  "config.mk" is created by Cabal when the integer-gmp package is
  configured and this file is still untracked by Hadrian. This led to a
  tricky configure "race" because "config.mk" is built by the
  "setup-config" rule, but this rule is also used to find dependencies,
  in particular the "ghc-gmp.h" header, but the creation of this file
  was depending (without being tracked) on "config.mk".

  Now Hadrian only builds in-tree GMP if `--with-intree-gmp` is passed
  to the top-level configure script.

* in-tree GMP isn't built once for all in a fixed stage (Stage1)
  anymore. It is built per stage which is required if we build a
  cross-compiler

* switching between in-tree and external GMP is now supported without
  having to clean the build directory first.

* "wrappers.c" now includes "ghc-gmp.h" instead of "ghc.h". It
  helps ensuring that the build system generates "ghc-gmp.h".

* build in-tree GMP in "<root>/stageN/gmp/gmpbuild" and produce useful
  artefacts (libgmp.a, gmp.h, objs/*.o) in "<root>/stageN/gmp"

- - - - -
40d917fb by Vladislav Zavialov at 2020-02-18T20:16:07-05:00
Remove the MonadFail P instance

There were two issues with this instance:

* its existence meant that a pattern match failure in the P monad would
  produce a user-visible parse error, but the error message would not be
  helpful to the user

* due to the MFP migration strategy, we had to use CPP in Lexer.x,
  and that created issues for #17750

Updates haddock submodule.

- - - - -
5a1ce45d by Joshua Price at 2020-02-18T20:16:47-05:00
Fix unboxed tuple size limit (#17837)

- - - - -
192caf58 by Vladislav Zavialov at 2020-02-18T20:17:24-05:00
Fix testsuite driver output (#17847)

- - - - -
1500f089 by Sylvain Henry at 2020-02-18T20:18:12-05:00
Modules: Llvm (#13009)

- - - - -
d53e81c0 by Niklas Hambüchen at 2020-02-20T10:36:22-05:00
8.10 Release notes for atomic .o writes [skip ci]

- - - - -
19680ee5 by Niklas Hambüchen at 2020-02-20T10:37:53-05:00
8.10 Release notes for --disable-delayed-os-memory-return [skip ci]

- - - - -
74ad75e8 by Simon Peyton Jones at 2020-02-20T21:17:57-05:00
Re-implement unsafe coercions in terms of unsafe equality proofs

(Commit message written by Omer, most of the code is written by Simon
and Richard)

See Note [Implementing unsafeCoerce] for how unsafe equality proofs and
the new unsafeCoerce# are implemented.

New notes added:

- [Checking for levity polymorphism] in CoreLint.hs
- [Implementing unsafeCoerce] in base/Unsafe/Coerce.hs
- [Patching magic definitions] in Desugar.hs
- [Wiring in unsafeCoerce#] in Desugar.hs

Only breaking change in this patch is unsafeCoerce# is not exported from
GHC.Exts, instead of GHC.Prim.

Fixes #17443
Fixes #16893

NoFib
-----

--------------------------------------------------------------------------------
        Program           Size    Allocs    Instrs     Reads    Writes
--------------------------------------------------------------------------------
             CS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            CSD          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             FS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
              S          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             VS          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            VSD          -0.1%      0.0%     -0.0%     -0.0%     -0.1%
            VSM          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           anna          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           ansi          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           atom          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         awards          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         banner          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     bernouilli          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   binary-trees          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          boyer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         boyer2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           bspt          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      cacheprof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       calendar          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       cichelli          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        circsim          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       clausify          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
  comp_lab_zift          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       compress          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      compress2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    constraints          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   cryptarithm2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            cse          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   digits-of-e2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         dom-lt          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          eliza          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          event          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    exact-reals          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         exp3_8          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         expert          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
 fannkuch-redux          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          fasta          -0.1%      0.0%     -0.5%     -0.3%     -0.4%
            fem          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            fft          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           fft2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       fibheaps          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           fish          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          fluid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         fulsom          -0.1%      0.0%     +0.0%     +0.0%     +0.0%
         gamteb          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            gcd          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
    gen_regexps          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         genfft          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
             gg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           grep          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         hidden          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            hpg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            ida          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          infer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        integer          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      integrate          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   k-nucleotide          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          kahan          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        knights          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         lambda          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     last-piece          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           lcss          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           life          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           lift          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         linear          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      listcompr          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       listcopy          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       maillist          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         mandel          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        mandel2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           mate          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        minimax          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        mkhprog          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
     multiplier          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         n-body          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       nucleic2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           para          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      paraffins          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         parser          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        parstof          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            pic          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       pidigits          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          power          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         pretty          -0.1%      0.0%     -0.1%     -0.1%     -0.1%
         primes          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      primetest          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         prolog          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         puzzle          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         queens          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        reptile          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
reverse-complem          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        rewrite          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           rfib          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            rsa          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            scc          -0.1%      0.0%     -0.1%     -0.1%     -0.1%
          sched          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            scs          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         simple          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
          solid          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        sorting          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
  spectral-norm          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         sphere          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
         symalg          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
            tak          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      transform          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
       treejoin          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      typecheck          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
        veritas          -0.0%      0.0%     -0.0%     -0.0%     -0.0%
           wang          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
      wave4main          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
   wheel-sieve2          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
           x2n1          -0.1%      0.0%     -0.0%     -0.0%     -0.0%
--------------------------------------------------------------------------------
            Min          -0.1%      0.0%     -0.5%     -0.3%     -0.4%
            Max          -0.0%      0.0%     +0.0%     +0.0%     +0.0%
 Geometric Mean          -0.1%     -0.0%     -0.0%     -0.0%     -0.0%

Test changes
------------

- break006 is marked as broken, see #17833
- The compiler allocates less when building T14683 (an unsafeCoerce#-
  heavy happy-generated code) on 64-platforms. Allocates more on 32-bit
  platforms.
- Rest of the increases are tiny amounts (still enough to pass the
  threshold) in micro-benchmarks. I briefly looked at each one in a
  profiling build: most of the increased allocations seem to be because
  of random changes in the generated code.

Metric Decrease:
    T14683

Metric Increase:
    T12150
    T12234
    T12425
    T13035
    T14683
    T5837
    T6048

Co-Authored-By: Richard Eisenberg <rae at cs.brynmawr.edu>
Co-Authored-By: Ömer Sinan Ağacan <omeragacan at gmail.com>

- - - - -
6880d6aa by Sylvain Henry at 2020-02-20T21:18:48-05:00
Disentangle DynFlags and SDoc

Remove several uses of `sdocWithDynFlags`. The remaining ones are mostly
CodeGen related (e.g. depend on target platform constants) and will be
fixed separately.

Metric Decrease:
   T12425
   T9961
   WWRec
   T1969
   T14683

- - - - -
70a90110 by Julien Debon at 2020-02-20T21:19:27-05:00
doc(List): Add examples to GHC.List

* Add examples
* Cleanup documentation
* Clarify merge process and Marge bot

- - - - -
c8439fc7 by Peter Trommler at 2020-02-20T21:20:05-05:00
Fix testsuite on powerpc64le

Remove expect broken on recomp tests, #11260 was closed
by !2264 and #11323 most likely by !2264 as well.

GHCi scripts tests work on GHCi but not the external interpreter,
adjust test configuration accordingly. Fixes unexpected passes.

Mark test requiring DWARF expect fail on powerpc64[le] for #11261.

- - - - -
65b7256a by Ömer Sinan Ağacan at 2020-02-20T21:20:45-05:00
Use concatMap(M) instead of `concat . map` and the monadic variant

- - - - -
8b76d457 by Roland Senn at 2020-02-20T21:21:28-05:00
Fix #17832: Weird handling of exports named main in 8.10-rc1

Switching from `lookupGlobalOccRn_maybe` to `lookupInfoOccRn`
to check whether a `main` function is in scope. Unfortunately
`lookupGlobalOccRn_maybe` complains if there are multiple `main`
functions in scope.

- - - - -
466e1ad5 by Krzysztof Gogolewski at 2020-02-20T21:22:11-05:00
Use TTG for HsSplicedT constructor

The constructor HsSplicedT occurs only in the GhcTc pass.
This enforces this fact statically via TTG.

- - - - -
4e622fca by Alexis King at 2020-02-20T21:22:49-05:00
Normalize types when dropping absent arguments from workers

fixes #17852

- - - - -
a533e547 by Adam Sandberg Eriksson at 2020-02-20T21:23:31-05:00
Mention users guide and release notes in merge request template
- - - - -
05251b17 by Ben Gamari at 2020-02-20T21:24:08-05:00
gitlab-ci: Fix typo in BIN_DIST_PREP_TAR_COMP variable name
- - - - -
f44c7e67 by Ben Gamari at 2020-02-20T21:24:46-05:00
gitlab-ci: Avoid duplicating ~/.cabal contents with every build

Previously our attempt to cache the cabal store would
`cp cabal-cache ~/.cabal`. However, if the latter already
 existed this meant that we would end up with
~/.cabal/cabal-cache. Not only would this not help caching
but it would exponentially grow the size of ~/.cabal. Not
good!
- - - - -
c5ec9965 by Ben Gamari at 2020-02-20T21:56:13-05:00
GHC.Hs.Extension: Use Type instead of *

- - - - -
89cb4cc4 by Ben Gamari at 2020-02-20T21:56:13-05:00
Use Type instead of * in GHC

- - - - -
04eb0d6c by Ben Gamari at 2020-02-20T21:56:13-05:00
Enable -Wstar-is-type in -Wall

As noted in [proposal 0143][proposal] this is supposed to happen in
8.12.

Also fix an incorrect claim in the users guide that -Wstar-is-type is
enabled by default.

[proposal]: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0143-remove-star-kind.rst

- - - - -
6de966f1 by Andreas Klebinger at 2020-02-20T21:56:15-05:00
Fix #17724 by having occAnal preserve used bindings.

It sometimes happened that occAnal would remove bindings
as dead code by relying on bindings to be in dependency
order. The fix was contributed by SPJ.

- - - - -
abd7f962 by Ben Gamari at 2020-02-20T21:56:15-05:00
users-guide: Mention dependency on `exceptions` in release notes

Fixes #17845.

- - - - -
58175379 by Sylvain Henry at 2020-02-20T21:56:20-05:00
Hadrian: minor GMP refactoring

Somehow I forgot to totally remove `gmpContext` in
d7029cc09edc052c2f97effe33233c53340fcce0. This patch fixes it and adds
some additional comments.

- - - - -
33fa8d94 by Ryan Scott at 2020-02-20T21:56:21-05:00
Generalize liftData to work over any Quote (#17857)

The Overloaded Quotations proposal generalized the type of `lift`
to work over any `Quote`, but not the type of `liftData`, leading
to #17857. Thankfully, generalizing `liftData` is extremely
straightforward.

Fixes #17857.

- - - - -
3cea6795 by Sylvain Henry at 2020-02-20T21:56:23-05:00
Make: fix sdist target (#17848)

- - - - -
e2cce997 by Sylvain Henry at 2020-02-20T21:56:23-05:00
Hadrian: fix source-dist target (#17849)

- - - - -
0a4c89b2 by Matthew Pickering at 2020-02-21T20:44:45-05:00
Special case `mkTyConApp liftedTypeKind []`

We really need to make sure that these are shared because otherwise GHC
will allocate thousands of identical `TyConApp` nodes.

See #17292

-------------------------
Metric Decrease:
    haddock.Cabal
    T14683
-------------------------

- - - - -
0482f58a by Matthew Pickering at 2020-02-21T20:45:21-05:00
TH: wrapGenSyns, don't split the element type too much

The invariant which allowed the pervious method of splitting the type of
the body to find the type of the elements didn't work in the new
overloaded quotation world as the type can be something like
`WriterT () m a` rather than `Q a` like before.

Fixes #17839

- - - - -
be7068a6 by Vladislav Zavialov at 2020-02-21T20:45:59-05:00
Parser API annotations: RealSrcLoc

During parsing, GHC collects lexical information about AST nodes and
stores it in a map. It is needed to faithfully restore original source
code, e.g. compare these expressions:

	a =  b
	a  = b

The position of the equality sign is not recorded in the AST, so it must
be stored elsewhere.

This system is described in Note [Api annotations].

Before this patch, the mapping was represented by:

	Map (SrcSpan, AnnKeywordId) SrcSpan

After this patch, the mapping is represented by:

	Map (RealSrcSpan, AnnKeywordId) RealSrcSpan

The motivation behind this change is to avoid using the Ord SrcSpan
instance (required by Map here), as it interferes with #17632 (see the
discussion there).

SrcSpan is isomorphic to  Either String RealSrcSpan,  but we shouldn't
use those strings as Map keys. Those strings are intended as hints to
the user, e.g. "<interactive>" or "<compiler-generated code>", so they
are not a valid way to identify nodes in the source code.

- - - - -
240f5bf6 by Sylvain Henry at 2020-02-21T20:46:40-05:00
Modules: Driver (#13009)

submodule updates: nofib, haddock

- - - - -
9d094111 by Sylvain Henry at 2020-02-21T20:47:19-05:00
Hadrian: `docs` rule needs `configure` (#17840)

- - - - -
1674353a by Ben Gamari at 2020-02-23T17:31:19-05:00
fs: Port fixes from ghc-jailbreak repository

* Override rename, unlink, and remove
* Factor out wchar conversion

- - - - -
853210f2 by Adam Sandberg Ericsson at 2020-02-23T17:32:03-05:00
show gcc linker options in configure summary

- - - - -
2831544a by Adam Sandberg Ericsson at 2020-02-23T17:32:44-05:00
hadrian: docs depend on stage1 ghc

- - - - -
1d9df9e0 by Adam Sandberg Ericsson at 2020-02-23T17:33:23-05:00
ci: after 5ce63d52fed the linux bindist for doc-tarball has changed name

- - - - -
26e8fff3 by Vladislav Zavialov at 2020-02-24T02:05:30-05:00
Remove Ord SrcLoc, Ord SrcSpan

Before this patch, GHC relied on Ord SrcSpan to identify source elements, by
using SrcSpan as Map keys:

	blackList :: Map SrcSpan ()      -- compiler/GHC/HsToCore/Coverage.hs
	instanceMap :: Map SrcSpan Name  -- compiler/GHC/HsToCore/Docs.hs

Firstly, this design is not valid in presence of UnhelpfulSpan, as it
distinguishes between  UnhelpfulSpan "X"  and  UnhelpfulSpan "Y", but those
strings are messages for the user, unfit to serve as identifiers for source
elements.

Secondly, this design made it hard to extend SrcSpan with additional data.
Recall that the definition of SrcSpan is:

	data SrcSpan =
	    RealSrcSpan !RealSrcSpan
	  | UnhelpfulSpan !FastString

Say we want to extend the RealSrcSpan constructor with additional information:

	data SrcSpan =
	    RealSrcSpan !RealSrcSpan !AdditionalInformation
	  | UnhelpfulSpan !FastString

	getAdditionalInformation :: SrcSpan -> AdditionalInformation
	getAdditionalInformation (RealSrcSpan _ a) = a

Now, in order for  Map SrcSpan  to keep working correctly, we must *ignore* additional
information when comparing SrcSpan values:

	instance Ord SrcSpan where
	  compare (RealSrcSpan r1 _) (RealSrcSpan r2 _) = compare r1 r2
	  ...

However, this would violate an important law:

	a == b  therefore  f a == f b

Ignoring  AdditionalInformation  in comparisons would mean that with
f=getAdditionalInformation, the law above does not hold.

A more robust design is to avoid  Ord SrcSpan  altogether, which is what this patch implements.
The mappings are changed to use RealSrcSpan instead:

	blackList :: Set RealSrcSpan         -- compiler/GHC/HsToCore/Coverage.hs
	instanceMap :: Map RealSrcSpan Name  -- compiler/GHC/HsToCore/Docs.hs

All SrcSpan comparisons are now done with explicit comparison strategies:

	SrcLoc.leftmost_smallest
	SrcLoc.leftmost_largest
	SrcLoc.rightmost_smallest

These strategies are not subject to the law mentioned above and can easily
discard both the string stored in  UnhelpfulSpan  and  AdditionalInformation.

Updates haddock submodule.

- - - - -
5aa6c188 by Ben Gamari at 2020-02-24T02:06:09-05:00
users-guide: Shuffle text

- - - - -
e3f17413 by Ben Gamari at 2020-02-24T02:06:09-05:00
users-guide: Drop old release notes

- - - - -
84dd9610 by Ben Gamari at 2020-02-24T02:06:09-05:00
Bump directory submodule to 1.3.6.0

- - - - -
e295a024 by Stefan Pavikevik at 2020-02-24T20:53:44-05:00
check for safe arguments, raising error when invalid (fix #17720)

- - - - -
354e2787 by Krzysztof Gogolewski at 2020-02-24T20:54:35-05:00
Comments, small refactor

* Remove outdated Note [HsForAllTy tyvar binders] and [Context quantification].
  Since the wildcard refactor 1e041b7382, HsForAllTy no longer has an flag
  controlling explicity. The field `hsq_implicit` is gone too.
  The current situation is covered by Note [HsType binders] which is already
  linked from LHsQTyVars.
* Small refactor in CoreLint, extracting common code to a function
* Remove "not so sure about WpFun" in TcEvidence, per Richard's comment
  https://gitlab.haskell.org/ghc/ghc/merge_requests/852#note_223226
* Use mkIfThenElse in Foreign/Call, as it does exactly what we need.

- - - - -
1b1067d1 by Sylvain Henry at 2020-02-24T20:55:25-05:00
Modules: CmmToAsm (#13009)

- - - - -
621468f6 by Alexis King at 2020-02-26T15:08:09-05:00
Treat coercions as arguments for floating and inlining

This reverts commit 8924224ecfa065ebc67b96a90d01cf9d2edd0e77
and fixes #17787.

- - - - -
def486c9 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Allow libnuma library path to be specified

- - - - -
ed03d4e7 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Refactor gmp arguments

Move the gmp configuration to its own binding.

- - - - -
09b88384 by Ben Gamari at 2020-02-26T15:08:47-05:00
hadrian: Tell Cabal about integer-gmp library location

- - - - -
161e08c5 by Krzysztof Gogolewski at 2020-02-26T15:09:30-05:00
Remove dead code

* FailablePattern can no longer be created since ab51bee40c82
  Therefore, Opt_WarnMissingMonadFailInstances has no effect anymore.
* XWrap is no longer used, it was moved to an extension field

- - - - -
e0d09db3 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Use 8.8.3 to bootstrap on Windows

This should fix #17861.

- - - - -
972bcf3a by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Fix symlink test

Needs to `write` bytes, not str.

- - - - -
273e60de by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Add shell subcommand for debugging within CI environment

- - - - -
43b13ed3 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Fix colors on Darwin

Darwin sh doesn't support \e.

- - - - -
217546a7 by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Flush stdout buffers in InitEventLogging

Otherwise we are sensitive to libc's buffering strategy.
Similar to the issue fixed in 543dfaab166c81f46ac4af76918ce32190aaab22.

- - - - -
c7d4fa55 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Add run_hadrian subcommand

I've ruined two trees already by failing to pass --flavour to hadrian.
Let's factor this out so it can be reused during troubleshooting.

- - - - -
7dc54873 by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Allow tests to be marked as broken on the command line

This allows us to work-around distribution-specific breakage easily.

- - - - -
25e2458e by Ben Gamari at 2020-02-26T15:10:09-05:00
hadrian: Add --broken-test flag

This exposes the flag of the same name supported by the testsuite
driver.

- - - - -
55769996 by Ben Gamari at 2020-02-26T15:10:09-05:00
gitlab-ci: Mark some tests as broken on Alpine

- - - - -
9ee7f87d by Ben Gamari at 2020-02-26T15:10:09-05:00
SysTools: Don't use process jobs if they are broken

- - - - -
bfaa3961 by Ben Gamari at 2020-02-26T15:10:09-05:00
Bump hsc2hs submodule

Fixes name of C compiler.

- - - - -
b2b49a0a by Ben Gamari at 2020-02-26T15:10:09-05:00
testsuite: Make hasMetricsFile RHS more descriptive

- - - - -
817f93ea by Sylvain Henry at 2020-02-26T15:10:58-05:00
Modules: Core (#13009)

Update haddock submodule

- - - - -
74311e10 by Sebastian Graf at 2020-02-27T16:22:45-05:00
PmCheck: Implement Long-distance information with Covered sets

Consider

```hs
data T = A | B | C

f :: T -> Int
f A = 1
f x = case x of
  A -> 2
  B -> 3
  C -> 4
```

Clearly, the RHS returning 2 is redundant. But we don't currently see
that, because our approximation to the covered set of the inner case
expression just picks up the positive information from surrounding
pattern matches. It lacks the context sensivity that `x` can't be `A`
anymore!

Therefore, we adopt the conceptually and practically superior approach
of reusing the covered set of a particular GRHS from an outer pattern
match. In this case, we begin checking the `case` expression with the
covered set of `f`s second clause, which encodes the information that
`x` can't be `A` anymore. After this MR, we will successfully warn about
the RHS returning 2 being redundant.

Perhaps surprisingly, this was a great simplification to the code of
both the coverage checker and the desugarer.

Found a redundant case alternative in `unix` submodule, so we have to
bump it with a fix.

Metric Decrease:
    T12227

- - - - -
59c023ba by Adam Sandberg Ericsson at 2020-02-27T16:23:25-05:00
configure: correctly generate LIBRARY_template_haskell_VERSION

- - - - -
9be82389 by Krzysztof Gogolewski at 2020-02-28T02:35:35-05:00
boot: Remove remote origin check

Previously, we used relative paths in submodules. When cloning from
GitHub, they had to be manually tweaked.
Since a76b233d we use absolute paths, so this workaround can be removed.

- - - - -
f4b6b594 by Ben Gamari at 2020-02-28T02:36:12-05:00
nonmoving: Fix marking in compact regions

Previously we were tracing the object we were asked to mark, even if it
lives in a compact region. However, there is no need to do this; we need
only to mark the region itself as live.

I have seen a segfault due to this due to the concurrent mark seeing a
an object in the process of being compacted by the mutator.

- - - - -
f97d1fb6 by Alp Mestanogullari at 2020-02-28T02:36:59-05:00
base: use an explicit import list in System.Environment.ExecutablePath

This was making -Werror builds fail on Windows (at least with Hadrian).

- - - - -
66f5d6d6 by Simon Peyton Jones at 2020-02-28T22:03:23-05:00
Improve error handling for VTA + deferred type errors

This fixes #17792

See Note [VTA for out-of-scope functions] in TcExpr

- - - - -
37f12603 by Ilias Tsitsimpis at 2020-02-28T22:04:04-05:00
llvm-targets: Add arm-unknown-linux-gnueabi

Add arm-unknown-linux-gnueabi, which is used by Debian's ARM EABI port
(armel), as an LLVM target.

- - - - -
327b29e1 by Vladislav Zavialov at 2020-02-29T05:06:31-05:00
Monotonic locations (#17632)

When GHC is parsing a file generated by a tool, e.g. by the C preprocessor, the
tool may insert #line pragmas to adjust the locations reported to the user.

As the result, the locations recorded in RealSrcLoc are not monotonic. Elements
that appear later in the StringBuffer are not guaranteed to have a higher
line/column number.

In fact, there are no guarantees whatsoever, as #line pragmas can arbitrarily
modify locations. This lack of guarantees makes ideas such as #17544
infeasible.

This patch adds an additional bit of information to every SrcLoc:

	newtype BufPos = BufPos { bufPos :: Int }

A BufPos represents the location in the StringBuffer, unaffected by any
pragmas.

Updates haddock submodule.

Metric Increase:
    haddock.Cabal
    haddock.base
    haddock.compiler
    MultiLayerModules
    Naperian
    parsing001
    T12150

- - - - -
99d2de86 by Ben Gamari at 2020-02-29T05:07:10-05:00
plugins: Ensure that loadInterface plugins can see annotations

loadInterface replaces the `mi_decls`, `mi_insts`, `mi_fam_insts`,
`mi_rules`, `mi_anns` fields of ModIface with `undefined` before
inserting the interface into the EPS. However, we still want to give
loadInterface plugins access to these fields. Consequently, we want to
pass the unmodified `ModIface` the plugin.

- - - - -
a999ee96 by Xavier Denis at 2020-02-29T05:07:50-05:00
Rename ghci.sh and build.sh to ghci and build respectively

Convert hadrian buildscripts to unsuffixed, dashed form

final cleanups

- - - - -
b5fb58fd by Ömer Sinan Ağacan at 2020-02-29T05:08:36-05:00
Document and refactor a few things around bitmap scavenging

- Added a few comments in StgPAP
- Added a few comments and assertions in scavenge_small_bitmap and
  walk_large_bitmap
- Did tiny refactor in GHC.Data.Bitmap: added some comments, deleted
  dead code, used PlatformWordSize type.

- - - - -
18757cab by Sylvain Henry at 2020-02-29T05:09:25-05:00
Refactor runtime interpreter code

In #14335 we want to be able to use both the internal interpreter (for
the plugins) and the external interpreter (for TH and GHCi) at the same
time.

This patch performs some preliminary refactoring: the `hsc_interp` field
of HscEnv replaces `hsc_iserv` and is now used to indicate which
interpreter (internal, external) to use to execute TH and GHCi.

Opt_ExternalInterpreter flag and iserv options in DynFlags are now
queried only when we set the session DynFlags. It should help making GHC
multi-target in the future by selecting an interpreter according to the
selected target.

- - - - -
b86a6395 by Adam Sandberg Ericsson at 2020-02-29T05:10:06-05:00
docs: correct relative links to haddocks from users guide (fixes #17866)

- - - - -
0f55df7f by Adam Sandberg Ericsson at 2020-02-29T05:10:06-05:00
docs: correct link to th haddocks from users guide

- - - - -
252e5117 by Jean-Baptiste Mazon at 2020-02-29T05:10:46-05:00
rts: enforce POSIX numeric locale for heap profiles

- - - - -
34c7d230 by Sylvain Henry at 2020-02-29T05:11:27-05:00
Fix Hadrian's ``--configure`` (fix #17883)

- - - - -
04d30137 by Ömer Sinan Ağacan at 2020-02-29T05:12:06-05:00
Simplify IfaceIdInfo type

IfaceIdInfo type is confusing: there's practically no difference between
`NoInfo` and `HasInfo []`. The comments say NoInfo is used when
-fomit-interface-pragmas is enabled, but we don't need to distinguish
`NoInfo` from `HasInfo []` in when reading the interface so the
distinction is not important.

This patch simplifies the type by removing NoInfo. When we have no info
we use an empty list.

With this change we no longer read the info list lazily when reading an
IfaceInfoItem, but when reading an IfaceId the ifIdInfo field is
read lazily, so I doubt this is going to be a problem.

- - - - -
3979485b by Roland Senn at 2020-02-29T17:36:59+01:00
Show breakpoint locations of breakpoints which were ignored during :force (#2950)

GHCi is split up into 2 major parts: The user-interface (UI)
and the byte-code interpreter. With `-fexternal-interpreter`
they even run in different processes. Communication between
the UI and the Interpreter (called `iserv`) is done using
messages over a pipe. This is called `Remote GHCI` and
explained in the Note [Remote GHCi] in `compiler/ghci/GHCi.hs`.

To process a `:force` command the UI sends a `Seq` message
to the `iserv` process. Then `iserv` does the effective
evaluation of the value. When during this process a breakpoint
is hit, the `iserv` process has no additional information to
enhance the `Ignoring breakpoint` output with the breakpoint
location.

To be able to print additional breakpoint information,
there are 2 possible implementation choices:
1. Store the needed information in the `iserv` process.
2. Print the `Ignoring breakpoint` from the UI process.

For option 1 we need to store the breakpoint info redundantely
in 2 places and this is bad. Therfore option 2 was implemented
in this MR:
- The user enters a `force` command
- The UI sends  a `Seq` message to the `iserv` process.
- If processing of the `Seq` message hits a breakpoint,
  the `iserv` process returns control to the UI process.
- The UI looks up the source location of the breakpoint,
  and prints the enhanced `Ignoring breakpoint` output.
- The UI sends a `ResumeSeq` message to the `iserv` process,
  to continue forcing.

- - - - -
3cf7303b by Krzysztof Gogolewski at 2020-03-02T01:18:33-05:00
Remove dead code

* The names in PrelName and THNames are no longer used
  since TH merged types and kinds, Typeable is kind-polymorphic,
  .net support was removed
* unqualQuasiQuote no longer used since 6f8ff0bbad3b9fa3

- - - - -
dbea7e9d by Ilias Tsitsimpis at 2020-03-02T01:19:12-05:00
Do not define hs_atomic{read,write}64() on non-64bit

Do not define hs_atomicread64() and hs_atomicwrite64() on machines where
WORD_SIZE_IN_BITS is less than 64, just like we do with the rest of the atomic
functions which work on 64-bit values.

Without this, compilation fails on MIPSel and PowerPC with the following error:

/usr/bin/ld: /<<PKGBUILDDIR>>/libraries/ghc-prim/dist-install/build/libHSghc-prim-0.5.3_p.a(atomic.p_o): in function `hs_atomicread64':
atomic.c:(.text.hs_atomicread64+0x8): undefined reference to `__sync_add_and_fetch_8'
/usr/bin/ld: /<<PKGBUILDDIR>>/libraries/ghc-prim/dist-install/build/libHSghc-prim-0.5.3_p.a(atomic.p_o): in function `hs_atomicwrite64':
atomic.c:(.text.hs_atomicwrite64+0x38): undefined reference to `__sync_bool_compare_and_swap_8'

Fixes #17886.

- - - - -
7c0c76fb by Roland Senn at 2020-03-02T17:13:55-05:00
Set `ImpredicativeTypes` during :print command. (#14828)

If ImpredicativeTypes is not enabled, then `:print <term>` will fail if the
type of <term> has nested `forall`s or `=>`s.
This is because the GHCi debugger's internals will attempt to unify a
metavariable with the type of <term> and then display the result, but if the
type has nested `forall`s or `=>`s, then unification will fail.
As a result, `:print` will bail out and the unhelpful result will be
`<term> = (_t1::t1)` (where `t1` is a metavariable).

Beware: <term> can have nested `forall`s even if its definition doesn't use
RankNTypes! Here is an example from #14828:

  class Functor f where
    fmap :: (a -> b) -> f a -> f b

Somewhat surprisingly, `:print fmap` considers the type of fmap to have
nested foralls. This is because the GHCi debugger sees the type
`fmap :: forall f. Functor f => forall a b. (a -> b) -> f a -> f b`.
We could envision deeply instantiating this type to get the type
`forall f a b. Functor f => (a -> b) -> f a -> f b`,
but this trick wouldn't work for higher-rank types.

Instead, we adopt a simpler fix: enable `ImpredicativeTypes` when using
`:print` and friends in the GHCi debugger. This is allows metavariables
to unify with types that have nested (or higher-rank) `forall`s/`=>`s,
which makes `:print fmap` display as
`fmap = (_t1::forall a b. Functor f => (a -> b) -> f a -> f b)`, as expected.

Although ImpredicativeTypes is a somewhat unpredictable from a type inference
perspective, there is no danger in using it in the GHCi debugger, since all
of the terms that the GHCi debugger deals with have already been typechecked.

- - - - -
2a2f51d7 by Sylvain Henry at 2020-03-02T17:14:38-05:00
Use configure script to detect that we should use in-tree GMP on Windows

- - - - -
8c663c2c by Andreas Klebinger at 2020-03-04T16:12:14+01:00
Be explicit about how stack usage of mvar primops are covered.

This fixes #17893

[skip-ci]

- - - - -
cedd6f30 by Ben Gamari at 2020-03-05T14:53:12-05:00
rts: Add getCurrentThreadCPUTime helper

- - - - -
ace618cd by Ben Gamari at 2020-03-05T14:53:12-05:00
nonmoving-gc: Track time usage of nonmoving marking

- - - - -
022b5ad5 by Ben Gamari at 2020-03-05T14:53:12-05:00
Stats: Add sync pauses to +RTS -S output

- - - - -
06763234 by Ben Gamari at 2020-03-05T14:53:12-05:00
rts: Report nonmoving collector statistics in machine-readable output

- - - - -
70d2b995 by Ben Gamari at 2020-03-09T06:10:52-04:00
nonmoving: Fix collection of sparks

Previously sparks living in the non-moving heap would be promptly GC'd
by the minor collector since pruneSparkQueue uses the BF_EVACUATED flag,
which non-moving heap blocks do not have set.

Fix this by implementing proper support in pruneSparkQueue for
determining reachability in the non-moving heap. The story is told in
Note [Spark management in the nonmoving heap].

- - - - -
9668781a by Ben Gamari at 2020-03-09T06:11:30-04:00
gitlab-ci: Disable Sphinx documentation in Alpine build
- - - - -
8eb2c263 by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
Fix Windows breakage by not touching locales on Windows

- - - - -
b8dab057 by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
rts: ensure C numerics in heap profiles using Windows locales if needed

- - - - -
7d95260f by Jean-Baptiste Mazon at 2020-03-09T16:33:37-04:00
rts: refactor and comment profile locales

- - - - -
5b627813 by Ryan Scott at 2020-03-09T16:34:14-04:00
Use InstanceSigs in GND/DerivingVia-generated code (#17899)

Aside from making the generated code easier to read when
`-ddump-deriv` is enabled, this makes the error message in `T15073`
substantially simpler (see the updated `T15073` expected stderr).

Fixes #17899.

- - - - -
70b50778 by Ben Gamari at 2020-03-10T02:05:42-04:00
SysTools: Ensure that error parser can handle absolute paths on Windows

This fixes #17786, where the error parser fails to correctly handle the
drive name in absolute Windows paths.

Unfortunately I couldn't find a satisfactory way to test this.

- - - - -
85b861d8 by Ben Gamari at 2020-03-10T02:05:42-04:00
testsuite: Add test for #17786

This isn't pretty but it's perhaps better than nothing.

- - - - -
ee2c50cb by Sylvain Henry at 2020-03-10T02:06:33-04:00
Hadrian: track missing configure results

- - - - -
ca8f51d4 by Ömer Sinan Ağacan at 2020-03-10T02:07:22-04:00
Add regression test for T17904

Closes #17904

- - - - -
5fa9cb82 by Richard Eisenberg at 2020-03-10T12:29:46-04:00
anyRewritableTyVar now looks in RuntimeReps

Previously, anyRewritableTyVar looked only at the arg and res
of `arg -> res`, but their RuntimeReps are also subject to
rewriting. Easy to fix.

Test case: typecheck/should_compile/T17024

Fixes #17024.

- - - - -
5ba01d83 by Ben Price at 2020-03-10T12:30:27-04:00
Clarify a Lint message

When developing a plugin I had a shadowing problem, where I generated
code
  app = \f{v r7B} x{v r7B} -> f{v r7B} x{v r7B}
This is obviously wrong, since the occurrence of `f` to the right of the
arrow refers to the `x` binder (they share a Unique). However, it is
rather confusing when Lint reports
  Mismatch in type between binder and occurrence
  Var: x{v rB7}
since it is printing the binder, rather than the occurrence.
It is rather easy to read this as claiming there is something wrong with
the `x` occurrence!

We change the report to explicitly print both the binder and the
occurrence variables.

- - - - -
7b2c827b by Simon Peyton Jones at 2020-03-10T12:31:15-04:00
Comments only

Clarify code added in #17852 and MR !2724

- - - - -
3300eeac by Krzysztof Gogolewski at 2020-03-10T12:31:54-04:00
Misc cleanup

- Remove Note [Existentials in shift_con_pat].
  The function shift_con_pat has been removed 15 years ago in 23f40f0e9be6d4.
- Remove kcLookupTcTyCon - it's the same as tcLookupTcTyCon
- Remove ASSERT in tyConAppArgN. It's already done by getNth,
  and it's the only reason getNth exists.
- Remove unused function nextRole

- - - - -
abf5736b by Krzysztof Gogolewski at 2020-03-10T18:05:01+01:00
Typos in comments [skip ci]

- - - - -
bb586f89 by Ben Gamari at 2020-03-11T00:14:59-04:00
rts: Prefer darwin-specific getCurrentThreadCPUTime

macOS Catalina now supports a non-POSIX-compliant version of clock_gettime
which cannot use the clock_gettime codepath.

Fixes #17906.

- - - - -
20800b9a by Sylvain Henry at 2020-03-11T08:17:19-04:00
Split GHC.Iface.Utils module

* GHC.Iface.Recomp: recompilation avoidance stuff
* GHC.Iface.Make: mkIface*

Moved `writeIfaceFile` into GHC.Iface.Load alongside `readIface` and
renamed it `writeIface` for consistency.

- - - - -
1daa2029 by Greg Steuck at 2020-03-11T08:17:56-04:00
Fixed a minor typo in codegen.rst
- - - - -
0bc23338 by Ryan Scott at 2020-03-11T08:18:32-04:00
Re-quantify when generalising over rewrite rule types

Previously, `tcRules` would check for naughty quantification
candidates (see `Note [Naughty quantification candidates]` in
`TcMType`) when generalising over the type of a rewrite rule. This
caused sensible-looking rewrite rules (like those in #17710) to be
rejected. A more permissing (and easier-to-implement) approach is to
do what is described in `Note [Generalising in tcTyFamInstEqnGuts]`
in `TcTyClsDecls`: just re-quantify all the type variable binders,
regardless of the order in which the user specified them. After all,
the notion of type variable specificity has no real meaning in
rewrite rules, since one cannot "visibly apply" a rewrite rule.
I have written up this wisdom in
`Note [Re-quantify type variables in rules]` in `TcRules`.

As a result of this patch, compiling the `ExplicitForAllRules1` test
case now generates one fewer warning than it used to. As far as I can
tell, this is benign, since the thing that the disappearing warning
talked about was also mentioned in an entirely separate warning.

Fixes #17710.

- - - - -
336eac7e by Ben Gamari at 2020-03-11T08:19:08-04:00
testsuite: Mark ghci056 and ghcilink004 as fragile in unreg

As noted in #17018.

Also fix fragile declaration of T13786, which only runs in the normal
way.

- - - - -
c61b9b02 by Simon Peyton Jones at 2020-03-11T08:19:44-04:00
Deepen call stack for isIn

I see quite a few warnings like:

  WARNING: file compiler/utils/Util.hs, line 593
    Over-long elem in unionLists

But the call stack is uninformative.   Better to add HasDebugCallStack
to isIn.  Ditto isn'tIn.

- - - - -
3aa9b35f by Ömer Sinan Ağacan at 2020-03-11T08:20:27-04:00
Zero any slop after compaction in compacting GC

In copying GC, with the relevant debug flags enabled, we release the old
blocks after a GC, and the block allocator zeroes the space before
releasing a block. This effectively zeros the old heap.

In compacting GC we reuse the blocks and previously we didn't zero the
unused space in a compacting generation after compaction. With this
patch we zero the slop between the free pointer and the end of the block
when we're done with compaction and when switching to a new block
(because the current block doesn't have enough space for the next object
we're shifting).

- - - - -
8e6febce by Sylvain Henry at 2020-03-11T20:33:37-04:00
Refactor GHC.Driver.Session (Ways and Flags)

* extract flags and ways into their own modules (with some renaming)

* remove one SOURCE import of GHC.Driver.Session from GHC.Driver.Phases

* when GHC uses dynamic linking (WayDyn), `interpWays` was only
  reporting WayDyn even if the host was profiled (WayProf).  Now it
  returns both as expected (might fix #16803).

* `mkBuildTag :: [Way] -> String` wasn't reporting a canonical tag for
  differently ordered lists. Now we sort and nub the list to fix this.

- - - - -
bc41e471 by Sylvain Henry at 2020-03-11T20:33:37-04:00
Refactor interpreterDynamic and interpreterProfiled

* `interpreterDynamic` and `interpreterProfiled` now take `Interp`
  parameters instead of DynFlags

* slight refactoring of `ExternalInterp` so that we can read the iserv
  configuration (which is pure) without reading an MVar.

- - - - -
a6989971 by Sylvain Henry at 2020-03-11T20:33:37-04:00
Use a Set to represent Ways

Should make `member` queries faster and avoid messing up with missing
`nubSort`.

Metric Increase:
    hie002

- - - - -
cb93a1a4 by Ryan Scott at 2020-03-11T20:34:14-04:00
Make DeriveFunctor-generated code require fewer beta reductions

Issue #17880 demonstrates that `DeriveFunctor`-generated code is
surprisingly fragile when rank-_n_ types are involved. The culprit is
that `$fmap` (the algorithm used to generate `fmap` implementations)
was too keen on applying arguments with rank-_n_ types to lambdas,
which fail to typecheck more often than not.

In this patch, I change `$fmap` (both the specification and the
implementation) to produce code that avoids creating as many lambdas,
avoiding problems when rank-_n_ field types arise.
See the comments titled "Functor instances" in `TcGenFunctor` for a
more detailed description. Not only does this fix #17880, but it also
ensures that the code that `DeriveFunctor` generates will continue
to work after simplified subsumption is implemented (see #17775).

What is truly amazing is that #17880 is actually a regression
(introduced in GHC 7.6.3) caused by commit
49ca2a37bef18aa57235ff1dbbf1cc0434979b1e, the fix #7436. Prior to
that commit, the version of `$fmap` that was used was almost
identical to the one used in this patch! Why did that commit change
`$fmap` then? It was to avoid severe performance issues that would
arise for recursive `fmap` implementations, such as in the example
below:

```hs
data List a = Nil | Cons a (List a) deriving Functor

-- ===>

instance Functor List where
  fmap f Nil = Nil
  fmap f (Cons x xs) = Cons (f x) (fmap (\y -> f y) xs)
```

The fact that `\y -> f y` was eta expanded caused significant
performance overheads. Commit
49ca2a37bef18aa57235ff1dbbf1cc0434979b1e fixed this performance
issue, but it went too far. As a result, this patch partially
reverts 49ca2a37bef18aa57235ff1dbbf1cc0434979b1e.

To ensure that the performance issues pre-#7436 do not resurface,
I have taken some precautionary measures:

* I have added a special case to `$fmap` for situations where the
  last type variable in an application of some type occurs directly.
  If this special case fires, we avoid creating a lambda expression.
  This ensures that we generate
  `fmap f (Cons x xs) = Cons (f x) (fmap f xs)` in the derived
  `Functor List` instance above. For more details, see
  `Note [Avoid unnecessary eta expansion in derived fmap implementations]`
  in `TcGenFunctor`.
* I have added a `T7436b` test case to ensure that the performance
  of this derived `Functor List`-style code does not regress.

When implementing this, I discovered that `$replace`, the algorithm
which generates implementations of `(<$)`, has a special case that is
very similar to the `$fmap` special case described above. `$replace`
marked this special case with a custom `Replacer` data type, which
was a bit overkill. In order to use the same machinery for both
`Functor` methods, I ripped out `Replacer` and instead implemented
a simple way to detect the special case. See the updated commentary
in `Note [Deriving <$]` for more details.

- - - - -
1f9db3e7 by Kirill Elagin at 2020-03-12T09:45:51-04:00
pretty-printer: Properly parenthesise LastStmt

After ApplicatveDo strips the last `return` during renaming, the pretty
printer has to restore it. However, if the return was followed by `$`,
the dollar was stripped too and not restored.

For example, the last stamement in:

```
  foo = do
    x <- ...
    ...
    return $ f x
```

would be printed as:

```
    return f x
```

This commit preserved the dolar, so it becomes:

```
    return $ f x
```

- - - - -
5cb93af7 by Kirill Elagin at 2020-03-12T09:45:51-04:00
pretty-printer: Do not print ApplicativeDo join

* Do not print `join` in ApplictiveStmt, unless ppr-debug
* Print parens around multiple parallel binds

When ApplicativeDo is enabled, the renamer analyses the statements of a
`do` block and in certain cases marks them as needing to be rewritten
using `join`.

For example, if you have:

```
foo = do
  a <- e1
  b <- e2
  doSomething a b
```

it will be desugared into:

```
foo = join (doSomething <$> e1 <*> e2)
```

After renaming but before desugaring the expression is stored
essentially as:

```
foo = do
  [will need join] (a <- e1 | b <- e2)
  [no return] doSomething a b
```

Before this change, the pretty printer would print a call to `join`,
even though it is not needed at this stage at all. The expression will be
actually rewritten into one using join only at desugaring, at which
point a literal call to join will be inserted.

- - - - -
3a259092 by Simon Peyton Jones at 2020-03-12T09:46:29-04:00
Expose compulsory unfoldings always

The unsafeCoerce# patch requires that unsafeCoerce# has
a compulsory unfolding that is always available.  So we have
to be careful to expose compulsory unfoldings unconditionally
and consistently.

We didn't get this quite right: #17871.  This patch fixes
it.  No real surprises here.

See Note [Always expose compulsory unfoldings] in GHC.Iface.Tidy

- - - - -
6a65b8c2 by Alp Mestanogullari at 2020-03-13T02:29:20-04:00
hadrian: improve dependency tracking for the check-* programs

The code in Rules.Register responsible for finding all the build artifacts
that Cabal installs when registering a library (static/shared libs, .hi files,
...) was looking in the wrong place. This patch fixes that logic and makes sure
we gather all those artifacts in a list to declare that the rule for a given
`.conf` file, our proxy for "Hadrian, please install this package in the package
db for this stage", also produces those artifacts under the said package
database.

We also were completely missing some logic to declare that the check-* programs
have dependencies besides their source code, at least when testing an in-tree
compiler.

Finally, this patch also removes redundant packages from 'testsuitePackages',
since they should already be covered by the stage<N>Packages lists from
Settings.Default.

With this patch, after a complete build and freezing stage 1, a change to
`compiler/parser/Parser.y` results in rebuilding the ghc lib, reinstalling it,
and rebuilding the few programs that depend on it, _including_ `check-ppr` and
`check-api-annotations` (therefore fixing #17273).

- - - - -
44fad4a9 by Sylvain Henry at 2020-03-13T02:30:22-04:00
Rename isDllName

I wanted to fix the dangling comment in `isDllName` ("This is the cause
of #", #8696 is already mentioned earlier). I took the opportunity to
change the function name to better reflect what it does.

- - - - -
2f292db8 by Paavo at 2020-03-13T02:31:03-04:00
Update documentation for closureSize

- - - - -
f124ff0d by Ben Gamari at 2020-03-13T02:31:40-04:00
gitlab-ci: Rework triggering of release builds

Use a push option instead of tagging.

- - - - -
7f25557a by Ben Gamari at 2020-03-13T10:38:09-04:00
gitlab-ci: Distinguish integer-simple test envs

Previously two integer-simple jobs declared the same test environment. One (the nightly job) was built in the perf way, the other in the validate way. Consequently they had appreciably different performance characteristics, causing in the nightly job to spuriously fail with performance changes.
- - - - -
c12a2ec5 by Simon Peyton Jones at 2020-03-14T05:25:30-04:00
Fix Lint

Ticket #17590 pointed out a bug in the way the linter dealt with
type lets, exposed by the new uniqAway story.

The fix is described in Note [Linting type lets]. I ended up
putting the in-scope Ids in a different env field, le_ids,
rather than (as before) sneaking them into the TCvSubst.

Surprisingly tiresome, but done.

Metric Decrease:
    hie002

- - - - -
b989845e by Sylvain Henry at 2020-03-14T05:26:11-04:00
Hadrian: fix absolute buildroot support (#17822)

Shake's "**" wildcard doesn't match absolute root. We must use "//" instead.

- - - - -
4f117135 by Sylvain Henry at 2020-03-14T05:26:49-04:00
Make: refactor GMP rules

Document and use simpler rules for the ghc-gmp.h header.

- - - - -
7432b327 by Sylvain Henry at 2020-03-14T05:27:28-04:00
Use correct option name (-opti) (fix #17314)

s/pgmo/opti

- - - - -
8f7dd571 by Judah Jacobson at 2020-03-14T05:28:07-04:00
Allow overriding LD_STAGE0 and AR_STAGE0 in the configure script.

Previously it was possible to override the stage0 C compiler via `CC_STAGE0`,
but you couldn't override `ld` or `ar` in stage0.  This change allows overriding them
by setting `LD_STAGE0` or `AR_STAGE0`, respectively.

Our team uses this feature internally to take more control of our GHC build
and make it run more hermetically.

- - - - -
7c3e39a9 by Judah Jacobson at 2020-03-14T05:28:07-04:00
Use AC_ARG_VAR for LD_STAGE0 and AR_STAGE0.

- - - - -
20d4d676 by Ben Gamari at 2020-03-14T05:28:43-04:00
nonmoving: Don't traverse filled segment list in pause

The non-moving collector would previously walk the entire filled segment
list during the preparatory pause. However, this is far more work than
is strictly necessary. We can rather get away with merely collecting the
allocators' filled segment list heads and process the lists themselves
during the concurrent phase. This can significantly reduce the maximum
gen1 GC pause time in programs with high rates of long-lived allocations.

- - - - -
fdfa2d01 by Ben Gamari at 2020-03-14T05:29:18-04:00
nonmoving: Remove redundant bitmap clearing

nonmovingSweep already clears the bitmap in the sweep loop. There is no
reason to do so a second time.

- - - - -
2f8c7767 by Simon Peyton Jones at 2020-03-14T05:29:55-04:00
Simple refactor of cheapEqExpr

No change in functionality.  Just seems tidier (and signficantly more
efficient) to deal with ticks directly than to call stripTicksTopE.

- - - - -
88f7a762 by Simon Peyton Jones at 2020-03-14T05:29:55-04:00
Improve CSE.combineAlts

This patch improves the way that CSE combines identical
alternatives.  See #17901.

I'm still not happy about the duplication between CSE.combineAlts
and GHC.Core.Utils.combineIdenticalAlts; see the Notes with those
functions.  But this patch is a step forward.

Metric Decrease:
    T12425
    T5642

- - - - -
8b95ddd3 by Ben Gamari at 2020-03-14T05:30:31-04:00
gitlab-ci: Add integer-simple release build for Windows

Closes #16144.

- - - - -
e3c374cc by Simon Peyton Jones at 2020-03-14T05:31:07-04:00
Wrap an implication around class-sig kind errors

Ticket #17841 showed that we can get a kind error
in a class signature, but lack an enclosing implication
that binds its skolems.

This patch

* Adds the wrapping implication: the new call to
  checkTvConstraints in tcClassDecl1

* Simplifies the API to checkTvConstraints, which
  was not otherwise called at all.

* Simplifies TcErrors.report_unsolved by *not*
  initialising the TidyEnv from the typechecker lexical
  envt.  It's enough to do so from the free vars of the
  unsolved constraints; and we get silly renamings if
  we add variables twice: once from the lexical scope
  and once from the implication constraint.

- - - - -
73133a3b by Simon Peyton Jones at 2020-03-14T05:31:07-04:00
Refactoring in TcSMonad

This patch is just refactoring: no change in
behaviour.

I removed the rather complicated
    checkConstraintsTcS
    checkTvConstraintsTcS

in favour of simpler functions
    emitImplicationTcS
    emitTvImplicationTcS
    pushLevelNoWorkList

The last of these is a little strange, but overall
it's much better I think.

- - - - -
93c88c26 by Ben Gamari at 2020-03-14T05:31:42-04:00
base: Make `open` calls interruptible

As noted in #17912, `open` system calls were `safe` rather than
`interruptible`. Consequently, the program could not be interrupted with
SIGINT if stuck in a slow open operation. Fix this by marking
`c_safe_open` as interruptible.

- - - - -
bee4cdad by Vladislav Zavialov at 2020-03-14T05:32:18-04:00
Remove second tcLookupTcTyCon in tcDataDefn

Before this patch, tcDataDefn used to call tcLookupTcTyCon twice in a row:
	1. in bindTyClTyVars itself
	2. in the continuation passed to it

Now bindTyClTyVars passes the TcTyCon to the continuation, making
the second lookup unnecessary.

- - - - -
3f116d35 by Cale Gibbard at 2020-03-14T19:34:42-04:00
Enable stage1 build of haddock

The submodule has already been bumped to contain the fix.

- - - - -
49e9d739 by Ömer Sinan Ağacan at 2020-03-14T19:35:24-04:00
rts: Fix printClosure when printing fwd ptrs

- - - - -
1de3ab4a by Krzysztof Gogolewski at 2020-03-14T19:36:04-04:00
Remove unused field var_inline (#17915)

- - - - -
d30aeb4b by Krzysztof Gogolewski at 2020-03-15T03:57:41-04:00
Document restriction on SCC pragma syntax

Currently, the names of cost centres must be quoted or
be lowercase identifiers.

Fixes #17916.

- - - - -
b4774598 by Brian Foley at 2020-03-15T03:58:18-04:00
Remove some dead code

>From the notes.ghc.drop list found using weeder in #17713

- - - - -
dd6ffe6b by Viktor Dukhovni at 2020-03-15T03:58:55-04:00
Note platform-specific Foreign.C.Types in context

Also fix the markup in the general note at the top of the module.  Haddock
(usability trade-off), does not support multi-line emphasised text.

- - - - -
2e82465f by Sylvain Henry at 2020-03-15T10:57:10-04:00
Refactor CmmToAsm (disentangle DynFlags)

This patch disentangles a bit more DynFlags from the native code
generator (CmmToAsm).

In more details:

- add a new NCGConfig datatype in GHC.CmmToAsm.Config which contains the
  configuration of a native code generation session
- explicitly pass NCGConfig/Platform arguments when necessary
- as a consequence `sdocWithPlatform` is gone and there are only a few
  `sdocWithDynFlags` left
- remove the use of `unsafeGlobalDynFlags` from GHC.CmmToAsm.CFG
- remove `sdocDebugLevel` (now we pass the debug level via NCGConfig)

There are still some places where DynFlags is used, especially because
of pretty-printing (CLabel), because of Cmm helpers (such as
`cmmExprType`) and because of `Outputable` instance for the
instructions. These are left for future refactoring as this patch is
already big.

- - - - -
c35c545d by Judah Jacobson at 2020-03-15T10:57:48-04:00
Add a -no-haddock flag.

This flag undoes the effect of a previous "-haddock" flag.  Having both flags makes it easier
for build systems to enable Haddock parsing in a set of global flags, but then disable it locally for
specific targets (e.g., third-party packages whose comments don't pass the validation in the latest GHC).

I added the flag to expected-undocumented-flags.txt since `-haddock` was alreadyin that list.

- - - - -
cfcc3c9a by Ömer Sinan Ağacan at 2020-03-15T10:58:27-04:00
Fix global_link of TSOs for threads reachable via dead weaks

Fixes #17785

Here's how the problem occurs:

- In generation 0 we have a TSO that is finished (i.e. it has no more
  work to do or it is killed).

- The TSO only becomes reachable after collectDeadWeakPtrs().

- After collectDeadWeakPtrs() we switch to WeakDone phase where we don't
  move TSOs to different lists anymore (like the next gen's thread list
  or the resurrected_threads list).

- So the TSO will never be moved to a generation's thread list, but it
  will be promoted to generation 1.

- Generation 1 collected via mark-compact, and because the TSO is
  reachable it is marked, and its `global_link` field, which is bogus at
  this point (because the TSO is not in a list), will be threaded.

- Chaos ensues.

In other words, when these conditions hold:

- A TSO is reachable only after collectDeadWeakPtrs()
- It's finished (what_next is ThreadComplete or ThreadKilled)
- It's retained by mark-compact collector (moving collector doesn't
  evacuate the global_list field)

We end up doing random mutations on the heap because the TSO's
global_list field is not valid, but it still looks like a heap pointer
so we thread it during compacting GC.

The fix is simple: when we traverse old_threads lists to resurrect
unreachable threads the threads that won't be resurrected currently
stays on the old_threads lists. Those threads will never be visited
again by MarkWeak so we now reset the global_list fields. This way
compacting GC does not thread pointers to nowhere.

Testing
-------

The reproducer in #17785 is quite large and hard to build, because of
the dependencies, so I'm not adding a regression test.

In my testing the reproducer would take a less than 5 seconds to run,
and once in every ~5 runs would fail with a segfault or an assertion
error. In other cases it also fails with a test failure. Because the
tests never fail with the bug fix, assuming the code is correct, this
also means that this bug can sometimes lead to incorrect runtime
results.

After the fix I was able to run the reproducer repeatedly for about an
hour, with no runtime crashes or test failures.

To run the reproducer clone the git repo:

    $ git clone https://github.com/osa1/streamly --branch ghc-segfault

Then clone primitive and atomic-primops from their git repos and point
to the clones in cabal.project.local. The project should then be
buildable using GHC HEAD. Run the executable `properties` with `+RTS -c
-DZ`.

In addition to the reproducer above I run the test suite using:

    $ make slowtest EXTRA_HC_OPTS="-debug -with-rtsopts=-DS \
        -with-rtsopts=-c +RTS -c -RTS" SKIPWAY='nonmoving nonmoving_thr'

This enables compacting GC always in both GHC when building the test
programs and when running the test programs, and also enables sanity
checking when running the test programs. These set of flags are not
compatible for all tests so there are some failures, but I got the same
set of failures with this patch compared to GHC HEAD.

- - - - -
818b3c38 by Lysxia at 2020-03-16T23:52:42-04:00
base: add strict IO functions: readFile', getContents', hGetContents'

- - - - -
18a346a4 by Sylvain Henry at 2020-03-16T23:53:24-04:00
Modules: Core (#13009)

Update submodule: haddock

- - - - -
92327e3a by Ömer Sinan Ağacan at 2020-03-16T23:54:04-04:00
Update sanity checking for TSOs:

- Remove an invalid assumption about GC checking what_next field. The GC
  doesn't care about what_next at all, if a TSO is reachable then all
  its pointers are followed (other than global_tso, which is only
  followed by compacting GC).

- Remove checkSTACK in checkTSO: TSO stacks will be visited in
  checkHeapChain, or checkLargeObjects etc.

- Add an assertion in checkTSO to check that the global_link field is
  sane.

- Did some refactor to remove forward decls in checkGlobalTSOList and
  added braces around single-statement if statements.

- - - - -
e1aa4052 by PHO at 2020-03-17T07:36:09-04:00
Don't use non-portable operator "==" in configure.ac

The test operator "==" is a Bash extension and produces a wrong result
if /bin/sh is not Bash.

- - - - -
89f034dd by Maximilian Tagher at 2020-03-17T07:36:48-04:00
Document the units of -ddump-timings

Right now, in the output of -ddump-timings to a file, you can't tell what the units are:

```
CodeGen [TemplateTestImports]: alloc=22454880 time=14.597
```

I believe bytes/milliseconds are the correct units, but confirmation would be appreciated. I'm basing it off of this snippet from `withTiming'`:

```
when (verbosity dflags >= 2 && prtimings == PrintTimings)
  $ liftIO $ logInfo dflags (defaultUserStyle dflags)
      (text "!!!" <+> what <> colon <+> text "finished in"
       <+> doublePrec 2 time
       <+> text "milliseconds"
       <> comma
       <+> text "allocated"
       <+> doublePrec 3 (realToFrac alloc / 1024 / 1024)
       <+> text "megabytes")
```

which implies time is in milliseconds, and allocations in bytes (which divided by 1024 would be KB, and again would be MB)

- - - - -
beffa147 by Simon Peyton Jones at 2020-03-17T07:37:25-04:00
Implement mapTyCo like foldTyCo

This patch makes mapType use the successful idiom described
in TyCoRep
   Note [Specialising foldType]

I have not yet changed any functions to use mapType, though there
may be some suitable candidates.

This patch should be a no-op in terms of functionality but,
because it inlines the mapper itself, I'm hoping that there may
be some modest perf improvements.

Metric Decrease:
    T5631
    T5642
    T3064
    T9020
    T14683
    hie002
    haddock.Cabal
    haddock.base
    haddock.compiler

- - - - -
5800ebfe by Ömer Sinan Ağacan at 2020-03-17T07:38:08-04:00
Don't update ModDetails with CafInfos when opts are disabled

This is consistent with the interface file behavior where we omit
HsNoCafRefs annotations with -fomit-interface-pragmas (implied by -O0).

ModDetails and ModIface are just different representations of the same
thing, so they really need to be in sync. This patch does the right
thing and does not need too much explanation, but here's an example of a
problem not doing this causes in !2842:

    -- MyInteger.hs
    module MyInteger
      ( MyInteger (MyInteger)
      , ToMyInteger (toMyInteger)
      ) where

    newtype MyInteger = MyInteger Integer

    class ToMyInteger a where
      toMyInteger :: a -> MyInteger

    instance ToMyInteger Integer where
      toMyInteger = MyInteger {- . succ -}

    -- Main.hs
    module Main
      ( main
      ) where

    import MyInteger (MyInteger (MyInteger), toMyInteger)

    main :: IO ()
    main = do
      let (MyInteger i) = (id . toMyInteger) (41 :: Integer)
      print i

If I build this with -O0, without this fix, we generate a ModDetails with
accurate LFInfo for toMyInteger (MyInteger.$fToMyIntegerInteger) which says that
it's a LFReEntrant with arity 1. This means in the use site (Main) we tag the
value:

    R3 = MyInteger.$fToMyIntegerInteger_closure + 1;
    R2 = GHC.Base.id_closure;
    R1 = GHC.Base.._closure;
    Sp = Sp - 16;
    call stg_ap_ppp_fast(R4, R3, R2, R1) args: 24, res: 0, upd: 24;

Now we change the definition by uncommenting the `succ` part and it becomes a thunk:

    MyInteger.$fToMyIntegerInteger [InlPrag=INLINE (sat-args=0)]
      :: MyInteger.ToMyInteger GHC.Integer.Type.Integer
    [GblId[DFunId(nt)]] =
        {} \u [] $ctoMyInteger_rEA;

and its LFInfo is now LFThunk. This change in LFInfo makes a difference in the
use site: we can no longer tag it.

But becuase the interface fingerprint does not change (because ModIface does not
change) we don't rebuild Main and tag the thunk.

(1.2% increase in allocations when building T12545 on armv7 because we
generate more code without CafInfos)

Metric Increase:
    T12545

- - - - -
5b632dad by Paavo at 2020-03-17T07:38:48-04:00
Add example for Data.Semigroup.diff

- - - - -
4d85d68b by Paavo at 2020-03-17T07:38:48-04:00
Clean up

- - - - -
75168d07 by Paavo at 2020-03-17T07:38:48-04:00
Make example collapsible

- - - - -
53ff2cd0 by Richard Eisenberg at 2020-03-17T13:46:57+00:00
Fix #17021 by checking more return kinds

All the details are in new Note [Datatype return kinds] in
TcTyClsDecls.

Test case: typecheck/should_fail/T17021{,b}
           typecheck/should_compile/T17021a

Updates haddock submodule

- - - - -
528df8ec by Sylvain Henry at 2020-03-18T10:06:43-04:00
Modules: Core operations (#13009)

- - - - -
4e8a71c1 by Richard Eisenberg at 2020-03-18T10:07:19-04:00
Add release note about fix to #16502.

We thought we needed to update the manual, but the fix for #16502
actually brings the implementation in line with the manual. So we
just alert users of how to update their code.

- - - - -
5cbf9934 by Andreas Klebinger at 2020-03-19T00:39:27-04:00
Update "GHC differences to the FFI Chapter" in user guide.

The old entry had a heavy focus on how things had been. Which is
not what I generally look for in a user guide.

I also added a small section on behaviour of nested safe ffi calls.

[skip-ci]

- - - - -
b03fd3bc by Sebastian Graf at 2020-03-19T00:40:06-04:00
PmCheck: Use ConLikeSet to model negative info

In #17911, Simon recognised many warnings stemming from over-long list
unions while coverage checking Cabal's `LicenseId` module.

This patch introduces a new `PmAltConSet` type which uses a `UniqDSet`
instead of an association list for `ConLike`s. For `PmLit`s, it will
still use an assocation list, though, because a similar map data
structure would entail a lot of busy work.

Fixes #17911.

- - - - -
64f20756 by Sylvain Henry at 2020-03-19T12:16:49-04:00
Refactoring: use Platform instead of DynFlags when possible

Metric Decrease:
    ManyConstructors
    T12707
    T13035
    T1969

- - - - -
cb1785d9 by Ömer Sinan Ağacan at 2020-03-19T12:16:54-04:00
FastString: fix eager reading of string ptr in hashStr

This read causes NULL dereferencing when len is 0.

Fixes #17909

In the reproducer in #17909 this bug is triggered as follows:

- SimplOpt.dealWithStringLiteral is called with a single-char string
  ("=" in #17909)

- tailFS gets called on the FastString of the single-char string.

- tailFS checks the length of the string, which is 1, and calls
  mkFastStringByteString on the tail of the ByteString, which is an
  empty ByteString as the original ByteString has only one char.

- ByteString's unsafeUseAsCStringLen returns (NULL, 0) for the empty
  ByteString, which is passed to mkFastStringWith.

- mkFastStringWith gets hash of the NULL pointer via hashStr, which
  fails on empty strings because of this bug.

- - - - -
73a7383e by Richard Eisenberg at 2020-03-20T20:42:56-04:00
Simplify treatment of heterogeneous equality

Previously, if we had a [W] (a :: k1) ~ (rhs :: k2), we would
spit out a [D] k1 ~ k2 and part the W as irreducible, hoping for
a unification. But we needn't do this. Instead, we now spit out
a [W] co :: k2 ~ k1 and then use co to cast the rhs of the original
Wanted. This means that we retain the connection between the
spat-out constraint and the original.

The problem with this new approach is that we cannot use the
casted equality for substitution; it's too like wanteds-rewriting-
wanteds. So, we forbid CTyEqCans that mention coercion holes.

All the details are in Note [Equalities with incompatible kinds]
in TcCanonical.

There are a few knock-on effects, documented where they occur.

While debugging an error in this patch, Simon and I ran into
infelicities in how patterns and matches are printed; we made
small improvements.

This patch includes mitigations for #17828, which causes spurious
pattern-match warnings. When #17828 is fixed, these lines should
be removed.

- - - - -
faa36e5b by Sylvain Henry at 2020-03-20T20:43:41-04:00
Hadrian: ignore in-tree GMP objects with ``--lint``

- - - - -
9a96ff6b by Richard Eisenberg at 2020-03-20T20:44:17-04:00
Update core spec to reflect changes to Core.

Key changes:
 * Adds a new rule for forall-coercions over coercion variables, which
was implemented but conspicuously missing from the spec.
 * Adds treatment for FunCo.
 * Adds treatment for ForAllTy over coercion variables.
 * Improves commentary (including restoring a Note lost in
03d4852658e1b7407abb4da84b1b03bfa6f6db3b) in the source.

No changes to running code.

- - - - -
7e0451c6 by Sergej Jaskiewicz at 2020-03-20T20:44:55-04:00
Fix event message in withTiming'

This typo caused generating 'end' events without the corresponding 'begin' events.

- - - - -
1542a626 by Ben Gamari at 2020-03-22T22:37:47-04:00
fs.h: Add missing declarations on Windows

- - - - -
3bcf2ccd by Ben Gamari at 2020-03-22T22:37:47-04:00
Bump process submodule

Avoids redundant case alternative warning.

- - - - -
3b363ef9 by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Normalize slashes in ghc-api annotations output

Enable `normalise_slashes` on `annotations`, `listcomps`, and
`parseTree` to fix Windows failures.

- - - - -
25fc9429 by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Update expected output on Windows

- - - - -
7f58ec6d by Ben Gamari at 2020-03-22T22:37:47-04:00
testsuite: Fix TOP of T17786

- - - - -
aadcd909 by GHC GitLab CI at 2020-03-22T22:37:47-04:00
testsuite: Update expected output on Windows

- - - - -
dc1eb10d by GHC GitLab CI at 2020-03-22T22:37:47-04:00
hadrian: Fix executable extension passed to testsuite driver

- - - - -
58f62e2c by GHC GitLab CI at 2020-03-22T22:37:47-04:00
gitlab-ci: Require that Windows-hadrian job passes

- - - - -
8dd2415d by Ben Gamari at 2020-03-22T22:37:47-04:00
hadrian: Eliminate redundant .exe from GHC path

Previously we were invoking:

    bash -c
    "c:/GitLabRunner/builds/eEQrxK4p/0/ghc/ghc/toolchain/bin/ghc.exe.exe
    testsuite/mk/ghc-config.hs -o _build/test/bin/ghc-config.exe"

- - - - -
373621f6 by Ben Gamari at 2020-03-22T22:37:47-04:00
Bump hsc2hs submodule

- - - - -
abc02b40 by Hécate at 2020-03-22T22:38:33-04:00
Annotate the non-total function in Data.Foldable as such

- - - - -
19f12557 by Josef Svenningsson at 2020-03-23T14:05:33-04:00
Fix ApplicativeDo regression #17835

A previous fix for #15344 made sure that monadic 'fail' is used properly
when translating ApplicativeDo. However, it didn't properly account
for when a 'fail' will be inserted which resulted in some programs
failing with a type error.

- - - - -
2643ba46 by Paavo at 2020-03-24T08:31:32-04:00
Add example and doc for Arg (Fixes #17153)

- - - - -
703221f4 by Roland Senn at 2020-03-25T14:45:04-04:00
Use export list of Main module in function TcRnDriver.hs:check_main (Fix #16453)

- Provide the export list of the `Main` module as parameter to the
  `compiler/typecheck/TcRnDriver.hs:check_main` function.
- Instead of `lookupOccRn_maybe` call the function `lookupInfoOccRn`.
  It returns the list `mains_all` of all the main functions in scope.
- Select from this list `mains_all` all `main` functions that are in
  the export list of the `Main` module.
- If this new list contains exactly one single `main` function, then
  typechecking continues.
- Otherwise issue an appropriate error message.

- - - - -
3e27205a by Sebastian Graf at 2020-03-25T14:45:40-04:00
Remove -fkill-absence and -fkill-one-shot flags

They seem to be a benchmarking vestige of the Cardinality paper and
probably shouldn't have been merged to HEAD in the first place.

- - - - -
262e42aa by Peter Trommler at 2020-03-25T22:41:39-04:00
Do not panic on linker errors

- - - - -
0de03cd7 by Sylvain Henry at 2020-03-25T22:42:02-04:00
DynFlags refactoring III

Use Platform instead of DynFlags when possible:
* `tARGET_MIN_INT` et al. replaced with `platformMinInt` et al.
* no more DynFlags in PreRules: added a new `RuleOpts` datatype
* don't use `wORD_SIZE` in the compiler
* make `wordAlignment` use `Platform`
* make `dOUBLE_SIZE` a constant

Metric Decrease:
    T13035
    T1969

- - - - -
7a04920b by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: fix a typo in liftA doc

This change removes an extra '|' that should not be rendered in
the liftA documentation.

Tracking: #17929

- - - - -
1c5a15f7 by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: add Control.Applicative optional example

This change adds an optional example.

Tracking: #17929

- - - - -
6d172e63 by Tristan Cacqueray at 2020-03-25T22:42:06-04:00
Base: add markup around Except

- - - - -
eb2162c8 by John Ericson at 2020-03-26T12:37:08-04:00
Remove unused `ghciTablesNextToCode` from compiler proper

- - - - -
f51efc4b by Joachim Breitner at 2020-03-26T12:37:09-04:00
Prepare to use run-time tablesNextToCode in compiler exclusively

Factor out CPP as much as possible to prepare for runtime
determinattion.

Progress towards #15548

- - - - -
1c446220 by Joachim Breitner at 2020-03-26T12:37:09-04:00
Use run-time tablesNextToCode in compiler exclusively (#15548)

Summary:

 - There is no more use of the TABLES_NEXT_TO_CODE CPP macro in
   `compiler/`. GHCI_TABLES_NEXT_TO_CODE is also removed entirely.
   The field within `PlatformMisc` within `DynFlags` is used instead.

 - The field is still not exposed as a CLI flag. We might consider some
   way to ensure the right RTS / libraries are used before doing that.

Original reviewers:

Original subscribers: TerrorJack, rwbarton, carter

Original Differential Revision: https://phabricator.haskell.org/D5082

- - - - -
1941ef4f by Sylvain Henry at 2020-03-29T17:28:51-04:00
Modules: Types (#13009)

Update Haddock submodule

Metric Increase:
   haddock.compiler

- - - - -
1c7c6f1a by Sylvain Henry at 2020-03-29T17:28:51-04:00
Remove GHC.Types.Unique.Map module

This module isn't used anywhere in GHC.

- - - - -
f1a6c73d by Sylvain Henry at 2020-03-29T17:28:51-04:00
Merge GHC.Types.CostCentre.Init into GHC.Driver.CodeOutput

- - - - -
54250f2d by Simon Peyton Jones at 2020-03-29T17:29:30-04:00
Demand analysis: simplify the demand for a RHS

Ticket #17932 showed that we were using a stupid demand for the RHS
of a let-binding, when the result is a product.  This was the result
of a "fix" in 2013, which (happily) turns out to no longer be
necessary.

So I just deleted the code, which simplifies the demand analyser,
and fixes #17932. That in turn uncovered that the anticipation
of worker/wrapper in CPR analysis was inaccurate, hence the logic
that decides whether to unbox an argument in WW was extracted into
a function `wantToUnbox`, now consulted by CPR analysis.

I tried nofib, and got 0.0% perf changes.

All this came up when messing about with !2873 (ticket #17917),
but is idependent of it.

Unfortunately, this patch regresses #4267 and realised that it is now
blocked on #16335.

- - - - -
03060b2f by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Fix T17786 on Windows

Fixes line ending normalization issue.

- - - - -
1f7995ba by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Fix T17786

Fix missing quoting and expected exit code.

- - - - -
ef9c608e by Ben Gamari at 2020-03-29T17:30:05-04:00
testsuite: Mark T12971 as broken on Windows

Due to #17945.

- - - - -
e54500c1 by Sylvain Henry at 2020-03-29T17:30:47-04:00
Store ComponentId details

As far as GHC is concerned, installed package components ("units") are
identified by an opaque ComponentId string provided by Cabal. But we
don't want to display it to users (as it contains a hash) so GHC queries
the database to retrieve some infos about the original source package
(name, version, component name).

This patch caches these infos in the ComponentId itself so that we don't
need to provide DynFlags (which contains installed package informations)
to print a ComponentId.

In the future we want GHC to support several independent package states
(e.g. for plugins and for target code), hence we need to avoid
implicitly querying a single global package state.

- - - - -
7e7cb714 by Marius Bakke at 2020-03-29T17:31:27-04:00
testsuite: Remove test that dlopens a PIE object.

glibc 2.30 disallowed dlopening PIE objects, so just remove the test.
Fixes #17952.

- - - - -
6c8f80d8 by Andreas Klebinger at 2020-03-29T17:32:04-04:00
Correct haddocks for testBit in Data.Bits

It conflated the nth bit with the bit at offset n.

Now we instead give the definition in terms of `bit and `.&.`
on top of clearer phrasing.

- - - - -
c916f190 by Andreas Klebinger at 2020-03-29T17:32:04-04:00
Apply suggestion to libraries/base/Data/Bits.hs
- - - - -
64bf7f51 by Ben Gamari at 2020-03-29T17:32:41-04:00
gitlab-ci: Add FreeBSD release job

- - - - -
a0d8e92e by Ryan Scott at 2020-03-29T17:33:20-04:00
Run checkNewDataCon before constraint-solving newtype constructors

Within `checkValidDataCon`, we used to run `checkValidType` on the
argument types of a newtype constructor before running
`checkNewDataCon`, which ensures that the user does not attempt
non-sensical things such as newtypes with multiple arguments or
constraints. This works out in most situations, but this falls over
on a corner case revealed in #17955:

```hs
newtype T = Coercible () T => T ()
```

`checkValidType`, among other things, peforms an ambiguity check on
the context of a data constructor, and that it turn invokes the
constraint solver. It turns out that there is a special case in the
constraint solver for representational equalities (read: `Coercible`
constraints) that causes newtypes to be unwrapped (see
`Note [Unwrap newtypes first]` in `TcCanonical`). This special case
does not know how to cope with an ill formed newtype like `T`, so
it ends up panicking.

The solution is surprisingly simple: just invoke `checkNewDataCon`
before `checkValidType` to ensure that the illicit newtype
constructor context is detected before the constraint solver can
run amok with it.

Fixes #17955.

- - - - -
45eb9d8c by Krzysztof Gogolewski at 2020-03-29T17:33:59-04:00
Minor cleanup

- Simplify mkBuildExpr, the function newTyVars was called
  only on a one-element list.
- TTG: use noExtCon in more places. This is more future-proof.
- In zonkExpr, panic instead of printing a warning.

- - - - -
8ce174b1 by Simon Jakobi at 2020-03-30T21:43:46+02:00
Use the new IntMap.disjoint function

Fixes #16806.

- - - - -


15 changed files:

- .ghcid
- .gitlab-ci.yml
- + .gitlab/ci.sh
- − .gitlab/darwin-init.sh
- + .gitlab/linters/check-changelogs.sh
- .gitlab/linters/check-cpp.py
- .gitlab/merge_request_templates/merge-request.md
- − .gitlab/prepare-system.sh
- − .gitlab/push-test-metrics.sh
- + .gitlab/test-metrics.sh
- − .gitlab/win32-init.sh
- HACKING.md
- aclocal.m4
- boot
- + compiler/GHC.hs


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/f2e3557544e13dc5247c8f8dc1ef2bb3e547e444...8ce174b180ab157b4e4d7d1693ca086d5bf17bf6

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/f2e3557544e13dc5247c8f8dc1ef2bb3e547e444...8ce174b180ab157b4e4d7d1693ca086d5bf17bf6
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