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

Commits:

• 3bfe7aa2
  by Matthew Pickering at 2025-12-07T12:18:57-05:00

  ci: Try using multi repl in ghc-in-ghci test
  
  This should be quite a bit faster than the ./hadrian/ghci command as it
  doesn't properly build all the dependencies.
  

• 2ef1601a
  by Rodrigo Mesquita at 2025-12-07T12:19:38-05:00

  Stack.Decode: Don't error on bitmap size 0
  
  A RET_BCO may have a bitmap with no payload.
  In that case, the bitmap = 0.
  
  One can observe this by using -ddump-bcos and interpreting
  
  ```
  main = pure ()
  ```
  
  Observe, for instance, that the BCO for this main function has size 0:
  
  ```
  ProtoBCO Main.main#0:
     \u []
         break<main:Main,0>() GHC.Internal.Base.pure
                                  GHC.Internal.Base.$fApplicativeIO GHC.Internal.Tuple.()
     bitmap:  0 []
     BRK_FUN <breakarray> main:Main 0 <cc>
     PACK     () 0
     PUSH_G   GHC.Internal.Base.$fApplicativeIO
     PUSH_APPLY_PP
     PUSH_G   GHC.Internal.Base.pure
     ENTER
  ```
  
  Perhaps we never tried to decode a stack in which a BCO like this was
  present. However, for the debugger, we want to decode stacks of threads
  stopped at breakpoints, and these kind of BCOs do get on a stack under
  e.g. `stg_apply_interp_info` frames.
  
  See the accompanying test in the next commit for an example to trigger
  the bug this commit fixes.
  
  Fixes #26640
  

• 747153d2
  by Rodrigo Mesquita at 2025-12-07T12:19:38-05:00

  Add test for #26640
  

• 493cd900
  by Simon Hengel at 2025-12-09T11:19:16-05:00

  Fix syntax error in gadt_syntax.rst

• 82f7fa00
  by Cheng Shao at 2025-12-09T11:19:16-05:00

  ci: fix "ci.sh clean" to address frequent out of space error on windows runners
  
  This patch fixes the `ci.sh clean` logic to address frequent out of
  space error on windows runners; previously it didn't clean up the
  inplace mingw blobs, which is the largest source of space leak on
  windows runners. See added comment for detailed explanation.
  

9 changed files:

• .gitlab-ci.yml
• .gitlab/ci.sh
• .gitlab/generate-ci/gen_ci.hs
• docs/users_guide/exts/gadt_syntax.rst
• libraries/ghc-internal/src/GHC/Internal/Stack/Decode.hs
• + testsuite/tests/bytecode/T26640.hs
• + testsuite/tests/bytecode/T26640.script
• + testsuite/tests/bytecode/T26640.stdout
• testsuite/tests/bytecode/all.T

Changes:

     # workaround for docker permissions

     - sudo chown ghc:ghc -R .

   variables:

-    GHC_FLAGS: -Werror

+    GHC_FLAGS: -Werror -Wwarn=unused-imports

   tags:

     - x86_64-linux

   script:

     - "echo '  ghc-options: -Werror'  >> hadrian/cabal.project.local"

     # Load ghc-in-ghci then immediately exit and check the modules loaded

     - export CORES="$(mk/detect-cpu-count.sh)"

-    - echo ":q" | HADRIAN_ARGS=-j$CORES hadrian/ghci -j$CORES | tail -n2 | grep "Ok,"

+    - echo ":q" | HADRIAN_ARGS=-j$CORES hadrian/ghci-multi -j$CORES | tail -n2 | grep "Ok,"

   after_script:

     - .gitlab/ci.sh save_cache

     - cat ci_timings.txt

 function fetch_ghc() {

   local should_fetch=false

-  

+

   if [ ! -e "$GHC" ]; then

     if [ -z "${FETCH_GHC_VERSION:-}" ]; then

       fail "GHC not found at '$GHC' and FETCH_GHC_VERSION is not set"

       fi

     fi

   fi

-  

+

   if [ "$should_fetch" = true ]; then

       local v="$FETCH_GHC_VERSION"

 }

 function clean() {

-  rm -R tmp

-  run rm -Rf _build

+  # When CI_DISPOSABLE_ENVIRONMENT is not true (e.g. using shell

+  # executor on windows/macos), the project directory is not removed

+  # by gitlab runner automatically after each job. To mitigate the

+  # space leak, other than periodic cleaning on the runner host, we

+  # also must aggressively cleanup build products, otherwise we run

+  # into out of space errors too frequently.

+  #

+  # When CI_DISPOSABLE_ENVIRONMENT is true (using docker executor on

+  # linux), the runner will do proper cleanup, so no need to do

+  # anything here.

+  #

+  # The exclude list are the artifacts that we do expect to be

+  # uploaded. Keep in sync with `jobArtifacts` in

+  # `.gitlab/generate-ci/gen_ci.hs`!

+  if [[ "${CI_DISPOSABLE_ENVIRONMENT:-}" != true ]]; then

+    git submodule foreach --recursive git clean -xdf

+    git clean -xdf \

+      --exclude=ci_timings.txt \

+      --exclude=ghc-*.tar.xz \

+      --exclude=junit.xml \

+      --exclude=unexpected-test-output.tar.gz

+  fi

 }

 function run_hadrian() {

       , if testsuiteUsePerf buildConfig then "RUNTEST_ARGS" =: "--config perf_path=perf" else mempty

       ]

+    -- Keep in sync with the exclude list in `function clean()` in

+    -- `.gitlab/ci.sh`!

     jobArtifacts = Artifacts

       { junitReport = "junit.xml"

       , expireIn = "2 weeks"

    ::

-          infix 6 (:--:)

+          infix 6 :--:

           data T a where

             (:--:) :: Int -> Bool -> T Int

     cWordArrayToList ptr size = mapM (peekElemOff ptr) [0 .. (size - 1)]

     usedBitmapWords :: Int -> Int

-    usedBitmapWords 0 = error "Invalid large bitmap size 0."

+    usedBitmapWords 0 = 0

     usedBitmapWords size = (size `div` fromIntegral wORD_SIZE_IN_BITS) + 1

     bitmapWordsPointerness :: Word -> [Word] -> [Pointerness]

+-- Main.hs

+module Main where

+main = pure ()

+

+:l T26640

+:break 3

+main

+import GHC.Conc

+import GHC.Stack.CloneStack

+() <- mapM_ (\ix -> do !_ <- decode =<< cloneThreadStack ix; return ()) =<< listThreads

+Breakpoint 0 activated at T26640.hs:3:8-14

+Stopped in Main.main, T26640.hs:3:8-14

+_result :: IO () = _

 test('T26565', extra_files(["T26565.hs"]), ghci_script, ['T26565.script'])

 test('T23973', extra_files(["T23973.hs"]), ghci_script, ['T23973.script'])

+test('T26640', extra_files(["T26640.hs"]), ghci_script, ['T26640.script'])

 # Nullary data constructors

 test('T26216', extra_files(["T26216_aux.hs"]), ghci_script, ['T26216.script'])