[Git][ghc/ghc][wip/T16762] 58 commits: Grammar for types and data/newtype constructors
Ryan Scott
gitlab at gitlab.haskell.org
Sun Sep 6 15:28:47 UTC 2020
Ryan Scott pushed to branch wip/T16762 at Glasgow Haskell Compiler / GHC
Commits:
686e06c5 by Vladislav Zavialov at 2020-08-06T13:34:05-04:00
Grammar for types and data/newtype constructors
Before this patch, we parsed types into a reversed sequence
of operators and operands. For example, (F x y + G a b * X)
would be parsed as [X, *, b, a, G, +, y, x, F],
using a simple grammar:
tyapps
: tyapp
| tyapps tyapp
tyapp
: atype
| PREFIX_AT atype
| tyop
| unpackedness
Then we used a hand-written state machine to assemble this
either into a type, using 'mergeOps',
or into a constructor, using 'mergeDataCon'.
This is due to a syntactic ambiguity:
data T1 a = MkT1 a
data T2 a = Ord a => MkT2 a
In T1, what follows after the = sign is a data/newtype constructor
declaration. However, in T2, what follows is a type (of kind
Constraint). We don't know which of the two we are parsing until we
encounter =>, and we cannot check for => without unlimited lookahead.
This poses a few issues when it comes to e.g. infix operators:
data I1 = Int :+ Bool :+ Char -- bad
data I2 = Int :+ Bool :+ Char => MkI2 -- fine
By this issue alone we are forced into parsing into an intermediate
representation and doing a separate validation pass.
However, should that intermediate representation be as low-level as a
flat sequence of operators and operands?
Before GHC Proposal #229, the answer was Yes, due to some particularly
nasty corner cases:
data T = ! A :+ ! B -- used to be fine, hard to parse
data T = ! A :+ ! B => MkT -- bad
However, now the answer is No, as this corner case is gone:
data T = ! A :+ ! B -- bad
data T = ! A :+ ! B => MkT -- bad
This means we can write a proper grammar for types, overloading it in
the DisambECP style, see Note [Ambiguous syntactic categories].
With this patch, we introduce a new class, DisambTD. Just like
DisambECP is used to disambiguate between expressions, commands, and patterns,
DisambTD is used to disambiguate between types and data/newtype constructors.
This way, we get a proper, declarative grammar for constructors and
types:
infixtype
: ftype
| ftype tyop infixtype
| unpackedness infixtype
ftype
: atype
| tyop
| ftype tyarg
| ftype PREFIX_AT tyarg
tyarg
: atype
| unpackedness atype
And having a grammar for types means we are a step closer to using a
single grammar for types and expressions.
- - - - -
6770e199 by Vladislav Zavialov at 2020-08-06T13:34:05-04:00
Clean up the story around runPV/runECP_P/runECP_PV
This patch started as a small documentation change, an attempt to make
Note [Parser-Validator] and Note [Ambiguous syntactic categories]
more clear and up-to-date.
But it turned out that runECP_P/runECP_PV are weakly motivated,
and it's easier to remove them than to find a good rationale/explanation
for their existence.
As the result, there's a bit of refactoring in addition to
a documentation update.
- - - - -
826d07db by Vladislav Zavialov at 2020-08-06T13:34:06-04:00
Fix debug_ppr_ty ForAllTy (#18522)
Before this change, GHC would
pretty-print forall k. forall a -> ()
as forall @k a. ()
which isn't even valid Haskell.
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0ddb4384 by Vladislav Zavialov at 2020-08-06T13:34:06-04:00
Fix visible forall in ppr_ty (#18522)
Before this patch, this type:
T :: forall k -> (k ~ k) => forall j -> k -> j -> Type
was printed incorrectly as:
T :: forall k j -> (k ~ k) => k -> j -> Type
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d2a43225 by Richard Eisenberg at 2020-08-06T13:34:06-04:00
Fail eagerly on a lev-poly datacon arg
Close #18534.
See commentary in the patch.
- - - - -
63348155 by Sylvain Henry at 2020-08-06T13:34:08-04:00
Use a type alias for Ways
- - - - -
9570c212 by Takenobu Tani at 2020-08-06T19:46:46-04:00
users-guide: Rename 8.12 to 9.0
GHC 8.12.1 has been renamed to GHC 9.0.1.
See also:
https://mail.haskell.org/pipermail/ghc-devs/2020-July/019083.html
[skip ci]
- - - - -
3907ee01 by Cale Gibbard at 2020-08-07T08:34:46-04:00
A fix to an error message in monad comprehensions, and a move of dsHandleMonadicFailure
as suggested by comments on !2330.
- - - - -
fa9bb70a by Cale Gibbard at 2020-08-07T08:34:46-04:00
Add some tests for fail messages in do-expressions and monad-comprehensions.
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5f036063 by Ben Gamari at 2020-08-07T08:35:21-04:00
cmm: Clean up Notes a bit
- - - - -
6402c124 by Ben Gamari at 2020-08-07T08:35:21-04:00
CmmLint: Check foreign call argument register invariant
As mentioned in Note [Register parameter passing] the arguments of
foreign calls cannot refer to caller-saved registers.
- - - - -
15b36de0 by Ben Gamari at 2020-08-07T08:35:21-04:00
nativeGen: One approach to fix #18527
Previously the code generator could produce corrupt C call sequences due
to register overlap between MachOp lowerings and the platform's calling
convention. We fix this using a hack described in Note [Evaluate C-call
arguments before placing in destination registers].
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3847ae0c by Ben Gamari at 2020-08-07T08:35:21-04:00
testsuite: Add test for #18527
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dd51d53b by Ben Gamari at 2020-08-07T08:35:21-04:00
testsuite: Fix prog001
Previously it failed as the `ghc` package was not visible.
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e4f1b73a by Alan Zimmerman at 2020-08-07T23:58:10-04:00
ApiAnnotations; tweaks for ghc-exactprint update
Remove unused ApiAnns, add one for linear arrow.
Include API Annotations for trailing comma in export list.
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8a665db6 by Ben Gamari at 2020-08-07T23:58:45-04:00
configure: Fix double-negation in ld merge-objects check
We want to only run the check if ld is gold.
Fixes the fix to #17962.
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a11c9678 by Adam Sandberg Ericsson at 2020-08-09T11:32:25+02:00
hadrian: depend on boot compiler version #18001
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c8873b52 by Alan Zimmerman at 2020-08-09T21:17:54-04:00
Api Annotations : Adjust SrcSpans for prefix bang (!).
And prefix ~
(cherry picked from commit 8dbee2c578b1f642d45561be3f416119863e01eb)
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77398b67 by Sylvain Henry at 2020-08-09T21:18:34-04:00
Avoid allocations in `splitAtList` (#18535)
As suspected by @simonpj in #18535, avoiding allocations in
`GHC.Utils.Misc.splitAtList` when there are no leftover arguments is
beneficial for performance:
On CI validate-x86_64-linux-deb9-hadrian:
T12227 -7%
T12545 -12.3%
T5030 -10%
T9872a -2%
T9872b -2.1%
T9872c -2.5%
Metric Decrease:
T12227
T12545
T5030
T9872a
T9872b
T9872c
- - - - -
8ba41a0f by Felix Yan at 2020-08-10T20:23:29-04:00
Correct a typo in ghc.mk
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1c469264 by Felix Yan at 2020-08-10T20:23:29-04:00
Add a closing parenthesis too
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acf537f9 by Sylvain Henry at 2020-08-10T20:24:09-04:00
Make splitAtList strict in its arguments
Also fix its slightly wrong comment
Metric Decrease:
T5030
T12227
T12545
- - - - -
ab4d1589 by Ben Gamari at 2020-08-11T22:18:03-04:00
typecheck: Drop SPECIALISE pragmas when there is no unfolding
Previously the desugarer would instead fall over when it realized that
there was no unfolding for an imported function with a SPECIALISE
pragma. We now rather drop the SPECIALISE pragma and throw a warning.
Fixes #18118.
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0ac8c0a5 by Ben Gamari at 2020-08-11T22:18:03-04:00
testsuite: Add test for #18118
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c43078d7 by Sven Tennie at 2020-08-11T22:18:38-04:00
Add hie.yaml to ghc-heap
This enables IDE support by haskell-language-server for ghc-heap.
- - - - -
f1088b3f by Ben Gamari at 2020-08-11T22:19:15-04:00
testsuite: Specify metrics collected by T17516
Previously it collected everything, including "max bytes used". This is
problematic since the test makes no attempt to control for deviations in
GC timing, resulting in high variability. Fix this by only collecting
"bytes allocated".
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accbc242 by Sylvain Henry at 2020-08-12T03:50:12-04:00
DynFlags: disentangle Outputable
- put panic related functions into GHC.Utils.Panic
- put trace related functions using DynFlags in GHC.Driver.Ppr
One step closer making Outputable fully independent of DynFlags.
Bump haddock submodule
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db6dd810 by Ben Gamari at 2020-08-12T03:50:48-04:00
testsuite: Increase tolerance of T16916
T16916 (testing #16916) has been slightly fragile in CI due to its
reliance on CPU times. While it's hard to see how to eliminate
the time-dependence entirely, we can nevertheless make it more tolerant.
Fixes #16966.
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bee43aca by Sylvain Henry at 2020-08-12T20:52:50-04:00
Rewrite and move the monad-state hack note
The note has been rewritten by @simonpj in !3851
[skip ci]
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25fdf25e by Alan Zimmerman at 2020-08-12T20:53:26-04:00
ApiAnnotations: Fix parser for new GHC 9.0 features
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7831fe05 by Ben Gamari at 2020-08-13T03:44:17-04:00
parser: Suggest ImportQualifiedPost in prepositive import warning
As suggested in #18545.
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55dec4dc by Sebastian Graf at 2020-08-13T03:44:52-04:00
PmCheck: Better long-distance info for where bindings (#18533)
Where bindings can see evidence from the pattern match of the `GRHSs`
they belong to, but not from anything in any of the guards (which belong
to one of possibly many RHSs).
Before this patch, we did *not* consider said evidence, causing #18533,
where the lack of considering type information from a case pattern match
leads to failure to resolve the vanilla COMPLETE set of a data type.
Making available that information required a medium amount of
refactoring so that `checkMatches` can return a
`[(Deltas, NonEmpty Deltas)]`; one `(Deltas, NonEmpty Deltas)` for each
`GRHSs` of the match group. The first component of the pair is the
covered set of the pattern, the second component is one covered set per
RHS.
Fixes #18533.
Regression test case: T18533
- - - - -
cf97889a by Hécate at 2020-08-13T03:45:29-04:00
Re-add BangPatterns to CodePage.hs
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ffc0d578 by Sylvain Henry at 2020-08-13T09:49:56-04:00
Add HomeUnit type
Since Backpack the "home unit" is much more involved than what it was
before (just an identifier obtained with `-this-unit-id`). Now it is
used in conjunction with `-component-id` and `-instantiated-with` to
configure module instantiations and to detect if we are type-checking an
indefinite unit or compiling a definite one.
This patch introduces a new HomeUnit datatype which is much easier to
understand. Moreover to make GHC support several packages in the same
instances, we will need to handle several HomeUnits so having a
dedicated (documented) type is helpful.
Finally in #14335 we will also need to handle the case where we have no
HomeUnit at all because we are only loading existing interfaces for
plugins which live in a different space compared to units used to
produce target code. Several functions will have to be refactored to
accept "Maybe HomeUnit" parameters instead of implicitly querying the
HomeUnit fields in DynFlags. Having a dedicated type will make this
easier.
Bump haddock submodule
- - - - -
8a51b2ab by Sylvain Henry at 2020-08-13T21:09:15-04:00
Make IOEnv monad one-shot (#18202)
On CI (x86_64-linux-deb9-hadrian, compile_time/bytes_allocated):
T10421 -1.8% (threshold: +/- 1%)
T10421a -1.7% (threshold: +/- 1%)
T12150 -4.9% (threshold: +/- 2%)
T12227 -1.6 (threshold: +/- 1%)
T12425 -1.5% (threshold: +/- 1%)
T12545 -3.8% (threshold: +/- 1%)
T12707 -3.0% (threshold: +/- 1%)
T13035 -3.0% (threshold: +/- 1%)
T14683 -10.3% (threshold: +/- 2%)
T3064 -6.9% (threshold: +/- 2%)
T4801 -4.3% (threshold: +/- 2%)
T5030 -2.6% (threshold: +/- 2%)
T5321FD -3.6% (threshold: +/- 2%)
T5321Fun -4.6% (threshold: +/- 2%)
T5631 -19.7% (threshold: +/- 2%)
T5642 -13.0% (threshold: +/- 2%)
T783 -2.7 (threshold: +/- 2%)
T9020 -11.1 (threshold: +/- 2%)
T9961 -3.4% (threshold: +/- 2%)
T1969 (compile_time/bytes_allocated) -2.2% (threshold: +/-1%)
T1969 (compile_time/max_bytes_used) +24.4% (threshold: +/-20%)
Additionally on other CIs:
haddock.Cabal -10.0% (threshold: +/- 5%)
haddock.compiler -9.5% (threshold: +/- 5%)
haddock.base (max bytes used) +24.6% (threshold: +/- 15%)
T10370 (max bytes used, i386) +18.4% (threshold: +/- 15%)
Metric Decrease:
T10421
T10421a
T12150
T12227
T12425
T12545
T12707
T13035
T14683
T3064
T4801
T5030
T5321FD
T5321Fun
T5631
T5642
T783
T9020
T9961
haddock.Cabal
haddock.compiler
Metric Decrease 'compile_time/bytes allocated':
T1969
Metric Increase 'compile_time/max_bytes_used':
T1969
T10370
haddock.base
- - - - -
9f66fdf6 by Ben Gamari at 2020-08-14T15:50:34-04:00
testsuite: Drop --io-manager flag from testsuite configuration
This is no longer necessary as there are now dedicated testsuite ways
which run tests with WinIO.
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55fd1dc5 by Ben Gamari at 2020-08-14T15:51:10-04:00
llvm-targets: Add i686 targets
Addresses #18422.
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f4cc57fa by Ben Gamari at 2020-08-18T15:38:55-04:00
Allow unsaturated runRW# applications
Previously we had a very aggressive Core Lint check which caught
unsaturated applications of runRW#. However, there is nothing
wrong with such applications and they may naturally arise in desugared
Core. For instance, the desugared Core of Data.Primitive.Array.runArray#
from the `primitive` package contains:
case ($) (runRW# @_ @_) (\s -> ...) of ...
In this case it's almost certain that ($) will be inlined, turning the
application into a saturated application. However, even if this weren't
the case there isn't a problem: CorePrep (after deleting an unnecessary
case) can simply generate code in its usual way, resulting in a call to
the Haskell definition of runRW#.
Fixes #18291.
- - - - -
3ac6ae7c by Ben Gamari at 2020-08-18T15:38:55-04:00
testsuite: Add test for #18291
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a87a0b49 by Eli Schwartz at 2020-08-18T15:39:30-04:00
install: do not install sphinx doctrees
These files are 100% not needed at install time, and they contain
unreproducible info. See https://reproducible-builds.org/ for why this
matters.
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194b25ee by Ben Gamari at 2020-08-18T15:40:05-04:00
testsuite: Allow baseline commit to be set explicitly
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fdcf7645 by Ben Gamari at 2020-08-18T15:40:05-04:00
gitlab-ci: Use MR base commit as performance baseline
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9ad5cab3 by Fendor at 2020-08-18T15:40:42-04:00
Expose UnitInfoMap as it is part of the public API
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aa4b744d by Ben Gamari at 2020-08-18T22:11:36-04:00
testsuite: Only run llvm ways if llc is available
As noted in #18560, we previously would always run the LLVM ways since
`configure` would set `SettingsLlcCommand` to something non-null when
it otherwise couldn't find the `llc` executable. Now we rather probe for
the existence of the `llc` executable in the testsuite driver.
Fixes #18560.
- - - - -
0c5ed5c7 by Sylvain Henry at 2020-08-18T22:12:13-04:00
DynFlags: refactor GHC.CmmToAsm (#17957, #10143)
This patch removes the use of `sdocWithDynFlags` from GHC.CmmToAsm.*.Ppr
To do that I've had to make some refactoring:
* X86' and PPC's `Instr` are no longer `Outputable` as they require a
`Platform` argument
* `Instruction` class now exposes `pprInstr :: Platform -> instr -> SDoc`
* as a consequence, I've refactored some modules to avoid .hs-boot files
* added (derived) functor instances for some datatypes parametric in the
instruction type. It's useful for pretty-printing as we just have to
map `pprInstr` before pretty-printing the container datatype.
- - - - -
731c8d3b by nineonine at 2020-08-19T18:47:39-04:00
Implement -Wredundant-bang-patterns (#17340)
Add new flag '-Wredundant-bang-patterns' that enables checks for "dead" bangs.
Dead bangs are the ones that under no circumstances can force a thunk that
wasn't already forced. Dead bangs are a form of redundant bangs. The new check
is performed in Pattern-Match Coverage Checker along with other checks (namely,
redundant and inaccessible RHSs). Given
f :: Bool -> Int
f True = 1
f !x = 2
we can detect dead bang patterns by checking whether @x ~ ⊥@ is satisfiable
where the PmBang appears in 'checkGrdTree'. If not, then clearly the bang is
dead. Such a dead bang is then indicated in the annotated pattern-match tree by
a 'RedundantSrcBang' wrapping. In 'redundantAndInaccessibles', we collect
all dead bangs to warn about.
Note that we don't want to warn for a dead bang that appears on a redundant
clause. That is because in that case, we recommend to delete the clause wholly,
including its leading pattern match.
Dead bang patterns are redundant. But there are bang patterns which are
redundant that aren't dead, for example
f !() = 0
the bang still forces the match variable, before we attempt to match on (). But
it is redundant with the forcing done by the () match. We currently don't
detect redundant bangs that aren't dead.
- - - - -
eb9bdaef by Simon Peyton Jones at 2020-08-19T18:48:14-04:00
Add right-to-left rule for pattern bindings
Fix #18323 by adding a few lines of code to handle non-recursive
pattern bindings. see GHC.Tc.Gen.Bind
Note [Special case for non-recursive pattern bindings]
Alas, this confused the pattern-match overlap checker; see #18323.
Note that this patch only affects pattern bindings like that
for (x,y) in this program
combine :: (forall a . [a] -> a) -> [forall a. a -> a]
-> ((forall a . [a] -> a), [forall a. a -> a])
breaks = let (x,y) = combine head ids
in x y True
We need ImpredicativeTypes for those [forall a. a->a] types to be
valid. And with ImpredicativeTypes the old, unprincipled "allow
unification variables to unify with a polytype" story actually
works quite well. So this test compiles fine (if delicatedly) with
old GHCs; but not with QuickLook unless we add this patch
- - - - -
293c7fba by Sylvain Henry at 2020-08-21T09:36:38-04:00
Put CFG weights into their own module (#17957)
It avoids having to query DynFlags to get them
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50eb4460 by Sylvain Henry at 2020-08-21T09:36:38-04:00
Don't use DynFlags in CmmToAsm.BlockLayout (#17957)
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659eb31b by Sylvain Henry at 2020-08-21T09:36:38-04:00
NCG: Dwarf configuration
* remove references to DynFlags in GHC.CmmToAsm.Dwarf
* add specific Dwarf options in NCGConfig instead of directly querying
the debug level
- - - - -
2d8ca917 by Sylvain Henry at 2020-08-21T09:37:15-04:00
Fix -ddump-stg flag
-ddump-stg was dumping the initial STG (just after Core-to-STG pass)
which was misleading because we want the final STG to know if a function
allocates or not. Now we have a new flag -ddump-stg-from-core for this and
-ddump-stg is deprecated.
- - - - -
fddddbf4 by Vladislav Zavialov at 2020-08-21T09:37:49-04:00
Import qualified Prelude in Cmm/Parser.y
In preparation for the next version of 'happy', c95920 added a qualified
import to GHC/Parser.y but for some reason neglected GHC/Cmm/Parser.y
This patch adds the missing qualified import to GHC/Cmm/Parser.y and
also adds a clarifying comment to explain why this import is needed.
- - - - -
989c1c27 by Ben Gamari at 2020-08-21T11:27:53-04:00
gitlab-ci: Test master branch as well
While these builds are strictly speaking redundant (since every commit
is tested by @marge-bot before making it into `master`), they are nevertheless
useful as they are displayed in the branch's commit list in GitLab's web interface.
Fixes #18595.
- - - - -
e67ae884 by Aditya Gupta at 2020-08-22T03:29:00-04:00
mkUnique refactoring (#18362)
Move uniqFromMask from Unique.Supply to Unique.
Move the the functions that call mkUnique from Unique to Builtin.Uniques
- - - - -
03cfcfd4 by Wander Hillen at 2020-08-22T03:29:36-04:00
Add ubuntu 20.04 jobs for nightly and release
- - - - -
3f501545 by Craig Ferguson at 2020-08-22T03:30:13-04:00
Utils: clarify docs slightly
The previous comment implies `nTimes n f` is either `f^{n+1}` or
`f^{2^n}` (when in fact it's `f^n`).
- - - - -
d0654f74 by Ryan Scott at 2020-08-22T09:47:06-04:00
WIP: T16762
[ci skip]
- - - - -
1b557251 by Ryan Scott at 2020-09-06T11:28:17-04:00
WIP: T16762 (part 2)
[ci skip]
- - - - -
30 changed files:
- .gitlab-ci.yml
- .gitlab/ci.sh
- aclocal.m4
- compiler/GHC.hs
- compiler/GHC/Builtin/Names.hs
- compiler/GHC/Builtin/Names/TH.hs
- compiler/GHC/Builtin/PrimOps.hs
- compiler/GHC/Builtin/Types.hs
- compiler/GHC/Builtin/Types.hs-boot
- compiler/GHC/Builtin/Types/Prim.hs
- compiler/GHC/Builtin/Uniques.hs
- compiler/GHC/Builtin/Uniques.hs-boot
- compiler/GHC/Builtin/Utils.hs
- compiler/GHC/ByteCode/Asm.hs
- compiler/GHC/Cmm.hs
- compiler/GHC/Cmm/CLabel.hs
- compiler/GHC/Cmm/CallConv.hs
- compiler/GHC/Cmm/CommonBlockElim.hs
- compiler/GHC/Cmm/DebugBlock.hs
- compiler/GHC/Cmm/Expr.hs
- compiler/GHC/Cmm/Info/Build.hs
- compiler/GHC/Cmm/LayoutStack.hs
- compiler/GHC/Cmm/Lint.hs
- compiler/GHC/Cmm/Liveness.hs
- compiler/GHC/Cmm/MachOp.hs
- compiler/GHC/Cmm/Node.hs
- compiler/GHC/Cmm/Opt.hs
- compiler/GHC/Cmm/Parser.y
- compiler/GHC/Cmm/Ppr/Decl.hs
- compiler/GHC/Cmm/Ppr/Expr.hs
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3f4428b42a5d61224aba5b7f74f5ecaf4b717094...1b557251a2f6e4ffcadc5806801792346df5c43e
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/3f4428b42a5d61224aba5b7f74f5ecaf4b717094...1b557251a2f6e4ffcadc5806801792346df5c43e
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