diff options
| -rw-r--r-- | lld/ELF/Symbols.cpp | 19 | ||||
| -rw-r--r-- | lld/test/ELF/common-shared.s | 16 |
2 files changed, 34 insertions, 1 deletions
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp index b5adbdca4a8..f81e73e5091 100644 --- a/lld/ELF/Symbols.cpp +++ b/lld/ELF/Symbols.cpp @@ -620,7 +620,18 @@ void Symbol::resolveCommon(const CommonSymbol &other) { return; if (cmp > 0) { - replace(other); + if (auto *s = dyn_cast<SharedSymbol>(this)) { + // Increase st_size if the shared symbol has a larger st_size. The shared + // symbol may be created from common symbols. The fact that some object + // files were linked into a shared object first should not change the + // regular rule that picks the largest st_size. + uint64_t size = s->size; + replace(other); + if (size > cast<CommonSymbol>(this)->size) + cast<CommonSymbol>(this)->size = size; + } else { + replace(other); + } return; } @@ -661,6 +672,12 @@ template <class LazyT> void Symbol::resolveLazy(const LazyT &other) { } void Symbol::resolveShared(const SharedSymbol &other) { + if (isCommon()) { + // See the comment in resolveCommon() above. + if (other.size > cast<CommonSymbol>(this)->size) + cast<CommonSymbol>(this)->size = other.size; + return; + } if (visibility == STV_DEFAULT && (isUndefined() || isLazy())) { // An undefined symbol with non default visibility must be satisfied // in the same DSO. diff --git a/lld/test/ELF/common-shared.s b/lld/test/ELF/common-shared.s new file mode 100644 index 00000000000..c53c5bf0ef7 --- /dev/null +++ b/lld/test/ELF/common-shared.s @@ -0,0 +1,16 @@ +# REQUIRES: x86 +## When a common symbol is merged with a shared symbol, pick the larger st_size. + +# RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o +# RUN: echo '.globl com; .comm com, 16' | llvm-mc -filetype=obj -triple=x86_64 - -o %t1.o +# RUN: ld.lld -shared %t1.o -o %t1.so + +# RUN: ld.lld %t.o %t1.so -o %t +# RUN: llvm-readelf -s %t | FileCheck %s +# RUN: ld.lld %t1.so %t.o -o %t +# RUN: llvm-readelf -s %t | FileCheck %s + +# CHECK: 16 OBJECT GLOBAL DEFAULT 7 com + +.globl com +.comm com,1 |
