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Marge Bot pushed to branch wip/marge_bot_batch_merge_job at Glasgow Haskell Compiler / GHC

Commits:

2f3cc9ff

by Simon Jakobi at 2026-06-08T07:55:49-04:00

testsuite: detect fast bignum via ghc-internal, not removed ghc-bignum

The ghc-bignum package was merged into ghc-internal, so the BIGNUM_GMP
probe in test.mk ran `ghc-pkg field ghc-bignum exposed-modules`, which
fails with "cannot find package ghc-bignum". That error went to stderr
and leaked into the captured stderr of every makefile_test, causing
spurious [bad stderr] failures across the suite. The probe also silently
returned empty, so config.have_fast_bignum was wrongly False even on GMP
builds.

Probe ghc-internal's extra-libraries for the gmp library instead: the
GMP backend module is an other-module (not exposed), but GMP_LIBS adds
gmp to extra-libraries only on a GMP build, so this distinguishes the
backends. Redirect stderr to keep any future missing-package error off
the harness's stderr.

This also removes a stale comment as per suggestion from hsyl20.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

eb3bf6e7

by Alan Zimmerman at 2026-06-08T07:56:32-04:00

EPA: Rename Transform.anchorEof to addModuleCommentOrigDeltas

This now matches what it actually does.

0dc97b12

by Brian McKenna at 2026-06-09T06:38:48-04:00

Ignore ticks in the pattern-match term oracle

The term-oracle in the pattern-match checker is keyed by a canonical
form of the scrutinee, computed by `makeDictsCoherent`. That canonical
form was tick-sensitive: two occurrences of an otherwise identical
expression that happened to carry different ticks were treated as
distinct values, breaking long-distance information.

This shows up in practice under `-finfo-table-map`, because the
desugarer wraps every record-selector use site in a `SourceNote`
carrying that site's span. For example:

     data Box = Box { unBox :: Maybe Int }
     f b = case unBox b of
       Nothing -> 0
       Just _  -> let Just x = unBox b in x

The two `unBox b` expressionss carry different SourceNote spans, the
pattern-match checker sees them as different, the long-distance
information from the outer `Just _` branch never reaches the
let-pattern, and `Just x = unBox b` is wrongly reported as
non-exhaustive.

We now strip all ticks in `makeDictsCoherent`.  This is documented as
Wrinkle (UD1) of Note [Unique dictionaries in the TmOracle CoreMap].

Fixes #27314

3465c065

by David Eichmann at 2026-06-09T06:38:49-04:00

Hadrian: remove unused wrapper scripts from windows bindist

These wrapper scripts are only installed on non-relocatable builds
which are not generally supported on windows.

8 changed files:

+ changelog.d/T27314.md
compiler/GHC/HsToCore/Pmc/Solver.hs
hadrian/src/Rules/BinaryDist.hs
testsuite/mk/test.mk
+ testsuite/tests/pmcheck/should_compile/T27314.hs
testsuite/tests/pmcheck/should_compile/all.T
utils/check-exact/Main.hs
utils/check-exact/Transform.hs

Changes:

changelog.d/T27314.md

 +section: compiler
 +issues: #27314
 +mrs: !16118
 +synopsis:
 +  Fix spurious ``-Wincomplete-uni-patterns`` warning under ``-finfo-table-map``.
 +description:
 +  The pattern-match checker now ignores ticks when comparing scrutinees in
 +  its CoreMap, so long-distance information is no longer lost across
 +  function-application scrutinees because debug source annotations
 +  (e.g. SourceNotes added by ``-finfo-table-map``) were inserted.

compiler/GHC/HsToCore/Pmc/Solver.hs

@@ -1000,8 +1000,9 @@ makeDictsCoherent (Case scrut bndr ty alts)
        , let expr' = makeDictsCoherent expr ]
  makeDictsCoherent (Cast expr co)
    = Cast (makeDictsCoherent expr) co
 -makeDictsCoherent (Tick tick expr)
 -  = Tick tick (makeDictsCoherent expr)
 +makeDictsCoherent (Tick _tick expr)
 +  -- See Wrinkle (UD1) in Note [Unique dictionaries in the TmOracle CoreMap]
 +  = makeDictsCoherent expr
  makeDictsCoherent ty@(Type {})
    = ty
  makeDictsCoherent co@(Coercion {})
@@ -1061,6 +1062,25 @@ In the end, replacing dictionaries with an error value in the pattern-match
  checker was the most self-contained, although we might want to revisit once
  we implement a more robust approach to computing equality in the pattern-match
  checker (see #19272).
++
 +Wrinkle (UD1): ticks
 +--------------------
 +'makeDictsCoherent' also drops all ticks. The CoreMap key represents
 +value-level equality, which ticks never affect.
++
 +Example (#27314): with -finfo-table-map every record-selector use site is
 +wrapped in a 'SourceNote' carrying that site's span (see
 +Note [Record-selector ticks] in GHC.HsToCore.Ticks). Given
++
 +    data Box = Box { unBox :: Maybe Int }
 +    f b = case unBox b of
 +      Nothing -> 0
 +      Just _  -> let Just x = unBox b in x
++
 +the two `unBox b`s carry different SourceNote spans. Without tick stripping
 +the CoreMap treats them as distinct expressions. Long-distance information
 +from the outer `Just _` branch therefore never reaches the let-pattern, and
 +`Just x = unBox b` is wrongly reported as non-exhaustive.
  -}
  {- Note [The Pos/Neg invariant]

hadrian/src/Rules/BinaryDist.hs

@@ -290,23 +290,25 @@ bindistRules = do
          copyFile ("hadrian" -/- "cfg" -/- "default.target.in") (bindistFilesDir -/- "default.target.in")
          copyFile ("hadrian" -/- "cfg" -/- "default.host.target.in") (bindistFilesDir -/- "default.host.target.in")
 -        -- todo: do we need these wrappers on windows
 -        forM_ bin_targets $ \(pkg, _) -> do
 -          needed_wrappers <- pkgToWrappers pkg
 -          forM_ needed_wrappers $ \wrapper_name -> do
 -            let suffix = if useGhcPrefix pkg
 -                           then "ghc-" ++ version
 -                           else version
 -            wrapper_content <- wrapper wrapper_name
 -            let unversioned_wrapper_path = bindistFilesDir -/- "wrappers" -/- wrapper_name
 -                versioned_wrapper = wrapper_name ++ "-" ++ suffix
 -                versioned_wrapper_path = bindistFilesDir -/- "wrappers" -/- versioned_wrapper
 -            -- Write the wrapper to the versioned path
 -            writeFile' versioned_wrapper_path wrapper_content
 -            -- Create a symlink from the non-versioned to the versioned.
 -            liftIO $ do
 -              IO.removeFile unversioned_wrapper_path <|> return ()
 -              IO.createFileLink versioned_wrapper unversioned_wrapper_path
 +        -- These wrapper scripts are only necessary in the configure/install
 +        -- workflow which is not supported on windows.
 +        unless windowsHost $ do
 +          forM_ bin_targets $ \(pkg, _) -> do
 +            needed_wrappers <- pkgToWrappers pkg
 +            forM_ needed_wrappers $ \wrapper_name -> do
 +              let suffix = if useGhcPrefix pkg
 +                            then "ghc-" ++ version
 +                            else version
 +              wrapper_content <- wrapper wrapper_name
 +              let unversioned_wrapper_path = bindistFilesDir -/- "wrappers" -/- wrapper_name
 +                  versioned_wrapper = wrapper_name ++ "-" ++ suffix
 +                  versioned_wrapper_path = bindistFilesDir -/- "wrappers" -/- versioned_wrapper
 +              -- Write the wrapper to the versioned path
 +              writeFile' versioned_wrapper_path wrapper_content
 +              -- Create a symlink from the non-versioned to the versioned.
 +              liftIO $ do
 +                IO.removeFile unversioned_wrapper_path <|> return ()
 +                IO.createFileLink versioned_wrapper unversioned_wrapper_path
      let buildBinDist compressor = do
            win_target <- isWinTarget

testsuite/mk/test.mk

@@ -109,9 +109,11 @@ endif
  HAVE_GDB := $(shell if gdb --version > /dev/null 2> /dev/null; then echo YES; else echo NO; fi)
  HAVE_READELF := $(shell if readelf --version > /dev/null 2> /dev/null; then echo YES; else echo NO; fi)
 -# we need a better way to find which backend is selected and if --check flag is
 -# used
 -BIGNUM_GMP := $(shell "$(GHC_PKG)" field ghc-bignum exposed-modules | grep GMP)
 +# Detect whether the fast (GMP) bignum backend is in use. The GMP backend module
 +# in ghc-internal is hidden, so we look instead for the gmp library it links
 +# against: GMP_LIBS adds gmp to ghc-internal's extra-libraries only on a GMP
 +# build.
 +BIGNUM_GMP := $(shell "$(GHC_PKG)" field ghc-internal extra-libraries 2>/dev/null | grep gmp)
  ifeq "$(filter thr, $(GhcRTSWays))" "thr"
  RUNTEST_OPTS += -e config.ghc_with_threaded_rts=True

testsuite/tests/pmcheck/should_compile/T27314.hs

 +module T27314 where
++
 +data Box = Box { unBox :: Maybe Int }
++
 +f :: Box -> Int
 +f b = case unBox b of
 +  Nothing -> 0
 +  Just _  -> let Just x = unBox b in x

testsuite/tests/pmcheck/should_compile/all.T

@@ -93,6 +93,7 @@ test('T21360', normal, compile, [overlapping_incomplete+'-Wincomplete-record-upd
  test('T21360b', normal, compile, [overlapping_incomplete+'-Wincomplete-record-updates'])
  test('T23520', normal, compile, [overlapping_incomplete+'-Wincomplete-record-updates'])
  test('T25164', [extra_files(['T25164_aux.hs']), req_th], multimod_compile, ['T25164', '-v0'])
 +test('T27314', normal, compile, ['-Wincomplete-uni-patterns -finfo-table-map'])
  # Other tests
  test('pmc001', [], compile, [overlapping_incomplete])

utils/check-exact/Main.hs

@@ -646,7 +646,7 @@ addLocaLDecl3 :: Changer
  addLocaLDecl3 libdir top = do
    Right newDecl <- withDynFlags libdir (\df -> parseDecl df "decl" "nn = 2")
    let
 -      doAddLocal = replaceDecls (anchorEof lp) [parent',d2']
 +      doAddLocal = replaceDecls (addModuleCommentOrigDeltas lp) [parent',d2']
          where
           lp = top
           (de1:d2:_) = hsDecls lp
@@ -667,7 +667,7 @@ addLocaLDecl4 libdir lp = do
    Right newDecl <- withDynFlags libdir (\df -> parseDecl df "decl" "nn = 2")
    Right newSig  <- withDynFlags libdir (\df -> parseDecl df "sig"  "nn :: Int")
    let
 -      doAddLocal = replaceDecls (anchorEof lp) (parent':ds)
 +      doAddLocal = replaceDecls (addModuleCommentOrigDeltas lp) (parent':ds)
          where
            (parent:ds) = hsDecls (makeDeltaAst lp)
@@ -781,7 +781,7 @@ rmDecl3 _libdir lp = do
  rmDecl4 :: Changer
  rmDecl4 _libdir lp = do
    let
 -      doRmDecl = replaceDecls (anchorEof lp) [de1',sd1]
 +      doRmDecl = replaceDecls (addModuleCommentOrigDeltas lp) [de1',sd1]
          where
           [de1] = hsDecls lp
           (de1',Just sd1) = modifyValD (getLocA de1) de1 $ \_m [sd1a,sd2] ->

utils/check-exact/Transform.hs

@@ -65,7 +65,7 @@ module Transform
          , balanceComments
          , balanceCommentsList
          , balanceCommentsListA
 -        , anchorEof
 +        , addModuleCommentOrigDeltas
          -- ** Managing lists, pure functions
          , captureOrderBinds
@@ -724,8 +724,8 @@ balanceSameLineComments (L la (Match anm mctxt pats (GRHSs x grhss lb)))
  -- ---------------------------------------------------------------------
 -anchorEof :: ParsedSource -> ParsedSource
 -anchorEof (L l m@(HsModule (XModulePs an _lo _ _) _mn _exps _imps _decls)) = L l (m { hsmodExt = (hsmodExt m){ hsmodAnn = an' } })
 +addModuleCommentOrigDeltas :: ParsedSource -> ParsedSource
 +addModuleCommentOrigDeltas (L l m@(HsModule (XModulePs an _lo _ _) _mn _exps _imps _decls)) = L l (m { hsmodExt = (hsmodExt m){ hsmodAnn = an' } })
    where
      an' = addCommentOrigDeltasAnn an