Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC

Commits:

• 7b616b9f
  by Cheng Shao at 2026-01-16T06:45:00-05:00

  compiler: fix regression when compiling foreign stubs in the rts unit
  
  This patch fixes a regression when compiling foreign stubs in the rts
  unit introduced in 05e25647f72bc102061af3f20478aa72bff6ff6e. A simple
  revert would fix it, but it's better to implement a proper fix with
  comment for better understanding of the underlying problem, see the
  added comment for explanation.
  
  Co-authored-by: Codex <codex@openai.com>
  

1 changed file:

• compiler/GHC/Driver/CodeOutput.hs

Changes:

                    mk_include i = "#include \"" ++ ST.unpack i ++ "\"\n"

                in case mrts_pkg of

                     Just rts_pkg -> concatMap mk_include (unitIncludes rts_pkg)

-                    -- This case only happens when compiling foreign stub for the rts

-                    -- library itself. The only time we do this at the moment is for

-                    -- IPE information for the RTS info tables

-                    Nothing -> ""

+                    -- The Nothing case only happens when compiling

+                    -- foreign stubs for the rts library itself (e.g.

+                    -- building with +ipe), and the rts unit is not

+                    -- registered yet.

+                    --

+                    -- The generated stubs may still use RTS API, so

+                    -- we must ensure that Rts.h is included,

+                    -- otherwise we may run into regressions (#26779).

+                    Nothing -> "#include \"Rts.h\"\n"

             -- wrapper code mentions the ffi_arg type, which comes from ffi.h

             ffi_includes