Author: Fangrui Song Date: 2022-08-08T12:39:51-07:00 New Revision: 4acca1b014ece0073fd33c384b86b7a29dd3df9d
URL: https://github.com/llvm/llvm-project/commit/4acca1b014ece0073fd33c384b86b7a29dd3df9d DIFF: https://github.com/llvm/llvm-project/commit/4acca1b014ece0073fd33c384b86b7a29dd3df9d.diff LOG: [ELF] mergeCmp: work around irreflexivity bug Some tests (e.g. aarch64-feature-pac.s) segfault in libstdc++ _GLIBCXX_DEBUG builds (enabled by LLVM_ENABLE_EXPENSIVE_CHECKS). dyn_cast<ThunkSection> is incorrectly true for any SyntheticSection. std::merge transitively calls mergeCmp(x, x) (due to __glibcxx_requires_irreflexive_pred) and will segfault in `ta->getTargetInputSection()`. The dyn_cast<ThunkSection> issue should be eventually fixed properly, bug `a != b` is robust enough for now. (cherry picked from commit abd9807590fc10eb92eb22aea7b50dbf08db7e9d) Added: Modified: lld/ELF/Relocations.cpp Removed: ################################################################################ diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp index e54e1ebd41bb8..53af34ef20855 100644 --- a/lld/ELF/Relocations.cpp +++ b/lld/ELF/Relocations.cpp @@ -1705,7 +1705,8 @@ static bool mergeCmp(const InputSection *a, const InputSection *b) { if (a->outSecOff < b->outSecOff) return true; - if (a->outSecOff == b->outSecOff) { + // FIXME dyn_cast<ThunkSection> is non-null for any SyntheticSection. + if (a->outSecOff == b->outSecOff && a != b) { auto *ta = dyn_cast<ThunkSection>(a); auto *tb = dyn_cast<ThunkSection>(b); _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
