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Zubin pushed to branch wip/9.12.3-backports at Glasgow Haskell Compiler / GHC

Commits:

91047c03

by Brandon Chinn at 2025-09-11T17:58:18+05:30

Fix for alex-3.5.2.0 (#25623)

This INLINE pragma for alexScanUser was added in 9.12, but then I
ported the change to alex in 3.5.2.0
(https://github.com/haskell/alex/pull/262).

I didn't realize that GHC errors on duplicate INLINE pragmas, so
this ended up being a breaking change.

This change should be backported into 9.12

(cherry picked from commit a1d923786baed5b001c523fd2a76f133be510b04)

1 changed file:

compiler/GHC/Parser/Lexer.x

Changes:

compiler/GHC/Parser/Lexer.x

@@ -41,6 +41,7 @@
  -- Alex "Haskell code fragment top"
+ {
 +{-# LANGUAGE CPP #-}
  {-# LANGUAGE ViewPatterns #-}
  {-# LANGUAGE LambdaCase #-}
  {-# LANGUAGE MultiWayIf #-}
@@ -3370,11 +3371,15 @@ topNoLayoutContainsCommas [] = False
  topNoLayoutContainsCommas (ALRLayout _ _ : ls) = topNoLayoutContainsCommas ls
  topNoLayoutContainsCommas (ALRNoLayout b _ : _) = b
 +#ifdef MIN_TOOL_VERSION_alex
 +#if !MIN_TOOL_VERSION_alex(3,5,2)
  -- If the generated alexScan/alexScanUser functions are called multiple times
  -- in this file, alexScanUser gets broken out into a separate function and
  -- increases memory usage. Make sure GHC inlines this function and optimizes it.
  -- https://github.com/haskell/alex/pull/262
  {-# INLINE alexScanUser #-}
 +#endif
 +#endif
  lexToken :: P (PsLocated Token)
  lexToken = do