Magnus pushed to branch wip/ci-note-treeless at Glasgow Haskell Compiler / GHC

Commits:

• d99f8326
  by Cheng Shao at 2025-12-11T19:14:18-05:00

  compiler: remove unused CPP code in foreign stub
  
  This patch removes unused CPP code in the generated foreign stub:
  
  - `#define IN_STG_CODE 0` is not needed, since `Rts.h` already
    includes this definition
  - The `if defined(__cplusplus)` code paths are not needed in the `.c`
    file, since we don't generate C++ stubs and don't include C++
    headers in our stubs. But it still needs to be present in the `.h`
    header since it might be later included into C++ source files.
  

• 46c9746f
  by Cheng Shao at 2025-12-11T19:14:57-05:00

  configure: bump LlvmMaxVersion to 22
  
  This commit bumps LlvmMaxVersion to 22; 21.x releases have been
  available since Aug 26th, 2025 and there's no regressions with 21.x so
  far. This bump is also required for updating fedora image to 43.
  

• 495389d3
  by Cheng Shao at 2025-12-12T09:01:59+00:00

  ci: use treeless fetch for perf notes
  
  This patch improves the ci logic for fetching perf notes by using
  treeless fetch
  (https://github.blog/open-source/git/get-up-to-speed-with-partial-clone-and-shallow-clone),
  to avoid downloading all blobs of the perf notes repo at once, and
  only fetch the actually required blobs on-demand when needed. This
  makes the initial `test-metrics.sh pull` operation much faster, and
  also more robust, since we are seeing an increasing rate of 504 errors
  in CI when fetching all perf notes at once, which is a major source of
  CI flakiness at this point.
  
  Co-authored-by: Codex <codex@openai.com>
  

3 changed files:

• .gitlab/test-metrics.sh
• compiler/GHC/Driver/CodeOutput.hs
• configure.ac

Changes:

 function pull() {

   local ref="refs/notes/$REF"

-  # 2023-10-04: `git fetch` started failing, first on Darwin in CI and then on

-  # Linux locally, both using git version 2.40.1. See #24055. One workaround is

-  # to set a larger http.postBuffer, although this is definitely a workaround.

-  # The default should work just fine. The error could be in git, GitLab, or

-  # perhaps the networking tube (including all proxies etc) between the two.

-  run git -c http.postBuffer=2097152 fetch -f "$NOTES_ORIGIN" "$ref:$ref"

+

+  # Fetch performance notes from a dedicated promisor remote using a

+  # treeless filter, so that individual note blobs are fetched lazily

+  # as needed.

+  git remote add perf-notes "$NOTES_ORIGIN" || true

+  git config fetch.recurseSubmodules false

+  git config remote.perf-notes.partialclonefilter tree:0

+  run git fetch --force perf-notes "$ref:$ref"

   echo "perf notes ref $ref is $(git rev-parse $ref)"

 }

   pull) pull ;;

   *) fail "Invalid mode $1" ;;

 esac

-

         stub_c_file_exists

            <- outputForeignStubs_help stub_c stub_c_output_w

-                ("#define IN_STG_CODE 0\n" ++

-                 "#include <Rts.h>\n" ++

-                 rts_includes ++

-                 ffi_includes ++

-                 cplusplus_hdr)

-                 cplusplus_ftr

-           -- We're adding the default hc_header to the stub file, but this

-           -- isn't really HC code, so we need to define IN_STG_CODE==0 to

-           -- avoid the register variables etc. being enabled.

+                (rts_includes ++

+                 ffi_includes) ""

         return (stub_h_file_exists, if stub_c_file_exists

                                        then Just stub_c

 # versions of LLVM simultaneously, but that stopped working around

 # 3.5/3.6 release of LLVM.

 LlvmMinVersion=13  # inclusive

-LlvmMaxVersion=21  # not inclusive

+LlvmMaxVersion=22  # not inclusive

 AC_SUBST([LlvmMinVersion])

 AC_SUBST([LlvmMaxVersion])