GitLab

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

Commits:

224446a2

by Cheng Shao at 2025-12-20T07:49:54-05:00

rts: workaround -Werror=maybe-uninitialized false positives

In some cases gcc might report -Werror=maybe-uninitialized that we
know are false positives, but need to workaround it to make validate
builds with -Werror pass.

251ec087

by Cheng Shao at 2025-12-20T07:49:54-05:00

hadrian: use -Og as C/C++ optimization level when debugging

This commit enables -Og as optimization level when compiling the debug
ways of rts. According to gcc documentation
(https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-Og),
-Og is a better choice than -O0 for producing debuggable code. It's
also supported by clang as well, so it makes sense to use it as a
default for debugging. Also add missing -g3 flag to C++ compilation
flags in +debug_info flavour transformer.

4 changed files:

hadrian/src/Flavour.hs
hadrian/src/Settings/Packages.hs
rts/linker/InitFini.c
rts/sm/Sanity.c

Changes:

hadrian/src/Flavour.hs

@@ -169,6 +169,7 @@ enableDebugInfo :: Flavour -> Flavour
  enableDebugInfo = addArgs $ notStage0 ? mconcat
      [ builder (Ghc CompileHs) ? pure ["-g3"]
      , builder (Ghc CompileCWithGhc) ? pure ["-optc-g3"]
 +    , builder (Ghc CompileCppWithGhc) ? pure ["-optcxx-g3"]
      , builder (Cc CompileC) ? arg "-g3"
      , builder (Cabal Setup) ? arg "--disable-library-stripping"
      , builder (Cabal Setup) ? arg "--disable-executable-stripping"

hadrian/src/Settings/Packages.hs

@@ -351,7 +351,7 @@ rtsPackageArgs = package rts ? do
            , Debug     `wayUnit` way          ? pure [ "-DDEBUG"
                                                      , "-fno-omit-frame-pointer"
                                                      , "-g3"
 -                                                    , "-O0" ]
 +                                                    , "-Og" ]
            -- Set the namespace for the rts fs functions
            , arg $ "-DFS_NAMESPACE=rts"

rts/linker/InitFini.c

@@ -75,7 +75,7 @@ static void sortInitFiniList(struct InitFiniList **slist, enum SortOrder order)
          while (*last != NULL && (*last)->next != NULL) {
              struct InitFiniList *s0 = *last;
              struct InitFiniList *s1 = s0->next;
 -            bool flip;
 +            bool flip = false;
              switch (order) {
                  case INCREASING: flip = s0->priority > s1->priority; break;
                  case DECREASING: flip = s0->priority < s1->priority; break;

rts/sm/Sanity.c

@@ -692,7 +692,7 @@ checkCompactObjects(bdescr *bd)
          ASSERT((W_)str == (W_)block + sizeof(StgCompactNFDataBlock));
          StgWord totalW = 0;
 -        StgCompactNFDataBlock *last;
 +        StgCompactNFDataBlock *last = block;
          for ( ; block ; block = block->next) {
              last = block;
              ASSERT(block->owner == str);