Magnus pushed to branch wip/mangoiv/bp-16719 at Glasgow Haskell Compiler / GHC

Commits:

• eb0cc0f1
  by Andreas Klebinger at 2026-11-02T11:01:01+01:00

  Fix a few tag inference bugs.
  
  * Treat bottoming functions and nullary join points as functions.
  * When generating bytecode don't rely on imported tag sigs.
  
  Fixes #27831, #27841 and #27842.
  
  (cherry picked from commit 6bbca56943ef68ba32520bcf8712a8faf9021ed6)
  

• 9e074512
  by Phil Hazelden at 2026-11-02T11:01:01+01:00

  Fix build with werror on glibc 2.43.
  
  We've been defining `_XOPEN_SOURCE` and `_POSIX_C_SOURCE` to the same
  values as defined in glibc prior to 2.43. But in 2.43, glibc changes
  them to new values, which means we get a warning when redefining them.
  By `#undef`ing them first, we no longer get a warning.
  
  Closes #27076.
  
  (cherry picked from commit 7b9a75f09a0a8d11d843f43e8e938b6608fb5166)
  

• 17f4f0da
  by Zubin Duggal at 2026-11-02T11:01:01+01:00

  DmdAnal: Make AbsDmd neutral in maxDmd
  
  fixes #27845
  
  (cherry picked from commit f76464cff4a9b55bb01e612bffe0dd866a9982e3)
  

• 551686d5
  by Luite Stegeman at 2026-11-02T11:01:02+01:00

  rts: move stack check to the start of the stg_unpack_cstring thunks
  
  fixes a deadlock
  
  see #27272
  
  (cherry picked from commit ff6d941afc5f113f7e8d7487e809584973281c60)
  

43 changed files:

• + changelog.d/27845
• + changelog.d/T27831-bottoming-strict-field
• + changelog.d/T27842-bytecode-imported-tags
• + changelog.d/caf-deadlock-27272
• compiler/GHC/Stg/InferTags.hs
• compiler/GHC/Stg/InferTags/Rewrite.hs
• compiler/GHC/Stg/InferTags/TagSig.hs
• compiler/GHC/Stg/InferTags/Types.hs
• compiler/GHC/Types/Demand.hs
• rts/StgStdThunks.cmm
• rts/include/rts/PosixSource.h
• + testsuite/tests/bytecode/T27842.hs
• + testsuite/tests/bytecode/T27842.stdout
• + testsuite/tests/bytecode/T27842A.hs
• + testsuite/tests/bytecode/T27842N.hs
• testsuite/tests/bytecode/all.T
• + testsuite/tests/dmdanal/should_run/T27845.hs
• + testsuite/tests/dmdanal/should_run/T27845.stdout
• + testsuite/tests/dmdanal/should_run/T27845_Lib.hs
• + testsuite/tests/dmdanal/should_run/T27845b.hs
• + testsuite/tests/dmdanal/should_run/T27845b.stdout
• + testsuite/tests/dmdanal/should_run/T27845b_Lib.hs
• testsuite/tests/dmdanal/should_run/all.T
• + testsuite/tests/rts/T27272.hs
• + testsuite/tests/rts/T27272_gen.py
• testsuite/tests/rts/all.T
• testsuite/tests/simplCore/should_compile/T4201.stdout
• testsuite/tests/simplCore/should_run/all.T
• testsuite/tests/simplStg/should_compile/all.T
• + testsuite/tests/simplStg/should_compile/inferTags005.hs
• + testsuite/tests/simplStg/should_compile/inferTags005.stderr
• + testsuite/tests/simplStg/should_compile/inferTags006.hs
• + testsuite/tests/simplStg/should_compile/inferTags006.stderr
• + testsuite/tests/simplStg/should_run/InferTags007_A.hs
• testsuite/tests/simplStg/should_run/Makefile
• − testsuite/tests/simplStg/should_run/T22042.stderr
• + testsuite/tests/simplStg/should_run/T27831.hs
• + testsuite/tests/simplStg/should_run/T27831.stdout
• + testsuite/tests/simplStg/should_run/T27857.hs
• + testsuite/tests/simplStg/should_run/T27857.stdout
• testsuite/tests/simplStg/should_run/all.T
• + testsuite/tests/simplStg/should_run/inferTags007.hs
• + testsuite/tests/simplStg/should_run/inferTags007.stdout

The diff was not included because it is too large.