[Git][ghc/ghc][wip/backports] 10 commits: CmmToC: don't add extern decl to parsed Cmm data

Ben Gamari gitlab at gitlab.haskell.org
Thu Jul 23 02:57:18 UTC 2020



Ben Gamari pushed to branch wip/backports at Glasgow Haskell Compiler / GHC


Commits:
e447bd2c by Sylvain Henry at 2020-07-22T22:57:09-04:00
CmmToC: don't add extern decl to parsed Cmm data

Previously, if a .cmm file *not in the RTS* contained something like:

```cmm
section "rodata" { msg : bits8[] "Test\n"; }
```

It would get compiled by CmmToC into:

```c
ERW_(msg);
const char msg[] = "Test\012";
```

and fail with:

```
/tmp/ghc32129_0/ghc_4.hc:5:12: error:
     error: conflicting types for \u2018msg\u2019
     const char msg[] = "Test\012";
                ^~~

In file included from /tmp/ghc32129_0/ghc_4.hc:3:0: error:

/tmp/ghc32129_0/ghc_4.hc:4:6: error:
     note: previous declaration of \u2018msg\u2019 was here
     ERW_(msg);
          ^

/builds/hsyl20/ghc/_build/install/lib/ghc-8.11.0.20200605/lib/../lib/x86_64-linux-ghc-8.11.0.20200605/rts-1.0/include/Stg.h:253:46: error:
     note: in definition of macro \u2018ERW_\u2019
     #define ERW_(X)   extern       StgWordArray (X)
                                                  ^
```

See the rationale for this on https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler/backends/ppr-c#prototypes

Now we don't generate these extern declarations (ERW_, etc.) for
top-level data. It shouldn't change anything for the RTS (the only place
we use .cmm files) as it is already special cased in
`GHC.Cmm.CLabel.needsCDecl`. And hand-written Cmm can use explicit
extern declarations when needed.

Note that it allows `cgrun069` test to pass with CmmToC (cf #15467).

(cherry picked from commit 499f3a2829d7c5a047c2ee87377d71ab2ea8c6d9)

- - - - -
f96a4b2c by Sylvain Henry at 2020-07-22T22:57:09-04:00
LLVM: refactor and comment register padding code (#17920)

(cherry picked from commit 9bdc2a056f459b0e05ddbc49d978dfed547ecc13)

- - - - -
36656d70 by Sylvain Henry at 2020-07-22T22:57:10-04:00
Add tests for #17920

Metric Decrease:
    T12150
    T12234

(cherry picked from commit aa54d1a2b2d2c89107cfa77d8c14a50d6ee9c140)

- - - - -
b7c216cb by Ben Gamari at 2020-07-22T22:57:10-04:00
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.

- - - - -
55fac768 by Travis Whitaker at 2020-07-22T22:57:10-04:00
Build a threaded stage 1 if the bootstrapping GHC supports it.

(cherry picked from commit 67738db10010fd28a8e997b5c8f83ea591b88a0e)
(cherry picked from commit a228d0a83db06fbe81b1c74fe3b1aea3133cee50)

- - - - -
bcf316aa by Joshua Price at 2020-07-22T22:57:10-04:00
Make `identifier` parse unparenthesized `->` (#18060)

(cherry picked from commit d6203f24cf421749616a247c047a9b44192f963a)

- - - - -
77dae8ae by Simon Peyton Jones at 2020-07-22T22:57:10-04:00
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.

(cherry picked from commit 3f431587c2db712136a3b5a353758ca63e1a5fd8)

- - - - -
b7c154c5 by Simon Peyton Jones at 2020-07-22T22:57:10-04:00
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.

(cherry picked from commit 9d87ced6832e75fce1e01b67bc6b7d9d1cf31efb)

- - - - -
2e90dd15 by Simon Peyton Jones at 2020-07-22T22:57:10-04:00
Major improvements to the specialiser

This patch is joint work of Alexis King and Simon PJ.  It does some
significant refactoring of the type-class specialiser.  Main highlights:

* We can specialise functions with types like
     f :: Eq a => a -> Ord b => b => blah
  where the classes aren't all at the front (#16473).  Here we can
  correctly specialise 'f' based on a call like
     f @Int @Bool dEqInt x dOrdBool
  This change really happened in an earlier patch
     commit 2d0cf6252957b8980d89481ecd0b79891da4b14b
     Author: Sandy Maguire <sandy at sandymaguire.me>
     Date:   Thu May 16 12:12:10 2019 -0400
  work that this new patch builds directly on that work, and refactors
  it a bit.

* We can specialise functions with implicit parameters (#17930)
     g :: (?foo :: Bool, Show a) => a -> String
  Previously we could not, but now they behave just like a non-class
  argument as in 'f' above.

* We can specialise under-saturated calls, where some (but not all of
  the dictionary arguments are provided (#17966).  For example, we can
  specialise the above 'f' based on a call
     map (f @Int dEqInt) xs
  even though we don't (and can't) give Ord dictionary.

  This may sound exotic, but #17966 is a program from the wild, and
  showed significant perf loss for functions like f, if you need
  saturation of all dictionaries.

* We fix a buglet in which a floated dictionary had a bogus demand
  (#17810), by using zapIdDemandInfo in the NonRec case of specBind.

* A tiny side benefit: we can drop dead arguments to specialised
  functions; see Note [Drop dead args from specialisations]

* Fixed a bug in deciding what dictionaries are "interesting"; see
  Note [Keep the old dictionaries interesting]

This is all achieved by by building on Sandy Macguire's work in
defining SpecArg, which mkCallUDs uses to describe the arguments of
the call. Main changes:

* Main work is in specHeader, which marched down the [InBndr] from the
  function definition and the [SpecArg] from the call site, together.

* specCalls no longer has an arity check; the entire mechanism now
  handles unders-saturated calls fine.

* mkCallUDs decides on an argument-by-argument basis whether to
  specialise a particular dictionary argument; this is new.
  See mk_spec_arg in mkCallUDs.

It looks as if there are many more lines of code, but I think that
all the extra lines are comments!

(cherry picked from commit 7052d7c7ce3418db9e66ad6ff31e80b2a2c724bb)

- - - - -
3e452a33 by Moritz Angermann at 2020-07-22T22:57:10-04:00
[linker] Fix out of range relocations.

mmap may return address all over the place. mmap_next will ensure we get
the next free page after the requested address.

This is especially important for linking on aarch64, where the memory model with PIC
admits relocations in the +-4GB range, and as such we can't work with
arbitrary object locations in memory.

Of note: we map the rts into process space, so any mapped objects must
not be ouside of the 4GB from the processes address space.

(cherry picked from commit aedfeb0b2b22172a0dfca0fe0c020ac80539d6ae)

- - - - -


30 changed files:

- compiler/GHC/StgToCmm/Prof.hs
- compiler/GHC/StgToCmm/Ticky.hs
- compiler/cmm/CLabel.hs
- compiler/cmm/CmmParse.y
- compiler/coreSyn/CoreSubst.hs
- compiler/coreSyn/CoreUnfold.hs
- compiler/deSugar/DsBinds.hs
- compiler/ghc.mk
- compiler/llvmGen/LlvmCodeGen/Base.hs
- compiler/llvmGen/LlvmCodeGen/CodeGen.hs
- compiler/parser/Parser.y
- compiler/specialise/Specialise.hs
- compiler/typecheck/TcCanonical.hs
- compiler/typecheck/TcClassDcl.hs
- compiler/typecheck/TcErrors.hs
- compiler/typecheck/TcEvidence.hs
- compiler/typecheck/TcSMonad.hs
- compiler/typecheck/TcTyClsDecls.hs
- compiler/typecheck/TcUnify.hs
- configure.ac
- ghc/ghc.mk
- hadrian/cfg/system.config.in
- hadrian/doc/user-settings.md
- hadrian/src/Expression.hs
- hadrian/src/Flavour.hs
- hadrian/src/Oracles/Flag.hs
- hadrian/src/Rules/Generate.hs
- hadrian/src/Settings/Default.hs
- hadrian/src/Settings/Packages.hs
- mk/config.mk.in


The diff was not included because it is too large.


View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fc6c41d2801d9ba5b7b64e13d0ed7bd6e74e0a15...3e452a33ac81dd39e4fdf64a8a5a4f33e8c025f1

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/fc6c41d2801d9ba5b7b64e13d0ed7bd6e74e0a15...3e452a33ac81dd39e4fdf64a8a5a4f33e8c025f1
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