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| author | Fangrui Song <maskray@google.com> | 2019-05-20 11:25:55 +0000 |
|---|---|---|
| committer | Fangrui Song <maskray@google.com> | 2019-05-20 11:25:55 +0000 |
| commit | 7c7425483ae621c5f197e999c0b49a8cdd5c5ace (patch) | |
| tree | e09f7310314e007bb84e33611496e3ee77dd95b9 | |
| parent | 95805bc425b264805a472232a75ed2ffe58aceda (diff) | |
| download | bcm5719-llvm-7c7425483ae621c5f197e999c0b49a8cdd5c5ace.tar.gz bcm5719-llvm-7c7425483ae621c5f197e999c0b49a8cdd5c5ace.zip | |
[ELF] Error on relocations to local undefined symbols
For a reference to a local symbol, ld.bfd and gold error if the symbol
is defined in a discarded section but accept it if the symbol is
undefined. This inconsistent behavior seems unnecessary for us (it
probably makes sense for them as they differentiate local/global
symbols, the error would mean more code).
Weaken the condition to getSymbol(Config->IsMips64EL) == 0 to catch such
errors. The symbol index can be 0 (e.g. R_*_NONE R_ARM_V4BX) and we shouldn't error on them.
Reviewed By: ruiu
Differential Revision: https://reviews.llvm.org/D61563
llvm-svn: 361144
| -rw-r--r-- | lld/ELF/Relocations.cpp | 10 | ||||
| -rw-r--r-- | lld/test/ELF/local-undefined-symbol.s | 8 |
2 files changed, 9 insertions, 9 deletions
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp index 74b46174dbf..fbdeb4f346b 100644 --- a/lld/ELF/Relocations.cpp +++ b/lld/ELF/Relocations.cpp @@ -675,7 +675,7 @@ static int64_t computeAddend(const RelTy &Rel, const RelTy *End, // Returns true if this function printed out an error message. static bool maybeReportUndefined(Symbol &Sym, InputSectionBase &Sec, uint64_t Offset) { - if (Sym.isLocal() || !Sym.isUndefined() || Sym.isWeak()) + if (!Sym.isUndefined() || Sym.isWeak()) return false; bool CanBeExternal = @@ -1012,7 +1012,8 @@ template <class ELFT, class RelTy> static void scanReloc(InputSectionBase &Sec, OffsetGetter &GetOffset, RelTy *&I, RelTy *End) { const RelTy &Rel = *I; - Symbol &Sym = Sec.getFile<ELFT>()->getRelocTargetSym(Rel); + uint32_t SymIndex = Rel.getSymbol(Config->IsMips64EL); + Symbol &Sym = Sec.getFile<ELFT>()->getSymbol(SymIndex); RelType Type; // Deal with MIPS oddity. @@ -1028,8 +1029,9 @@ static void scanReloc(InputSectionBase &Sec, OffsetGetter &GetOffset, RelTy *&I, if (Offset == uint64_t(-1)) return; - // Skip if the target symbol is an erroneous undefined symbol. - if (maybeReportUndefined(Sym, Sec, Rel.r_offset)) + // Error if the target symbol is undefined. Symbol index 0 may be used by + // marker relocations, e.g. R_*_NONE and R_ARM_V4BX. Don't error on them. + if (SymIndex != 0 && maybeReportUndefined(Sym, Sec, Rel.r_offset)) return; const uint8_t *RelocatedAddr = Sec.data().begin() + Rel.r_offset; diff --git a/lld/test/ELF/local-undefined-symbol.s b/lld/test/ELF/local-undefined-symbol.s index bff8c8bc1dc..c2ab207359b 100644 --- a/lld/test/ELF/local-undefined-symbol.s +++ b/lld/test/ELF/local-undefined-symbol.s @@ -1,10 +1,8 @@ # REQUIRES: x86 -# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t -# RUN: ld.lld %t -o %t1 -# RUN: llvm-readobj --symbols %t1 | FileCheck %s +# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o +# RUN: not ld.lld %t.o -o %t 2>&1 | FileCheck %s -# CHECK: Symbols [ -# CHECK-NOT: Name: foo +# CHECK: error: undefined symbol: foo .global _start _start: |
