diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/MC/MCELFStreamer.cpp | 40 |
1 files changed, 34 insertions, 6 deletions
diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp index 7f5f1b63e5..7faa6f411b 100644 --- a/lib/MC/MCELFStreamer.cpp +++ b/lib/MC/MCELFStreamer.cpp @@ -13,6 +13,7 @@ #include "llvm/MC/MCELFStreamer.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCCodeEmitter.h" #include "llvm/MC/MCContext.h" @@ -126,6 +127,26 @@ void MCELFStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) { Alias->setVariableValue(Value); } +// When GNU as encounters more than one .type declaration for an object it seems +// to use a mechanism similar to the one below to decide which type is actually +// used in the object file. The greater of T1 and T2 is selected based on the +// following ordering: +// STT_NOTYPE < STT_OBJECT < STT_FUNC < STT_GNU_IFUNC < STT_TLS < anything else +// If neither T1 < T2 nor T2 < T1 according to this ordering, use T2 (the user +// provided type). +static unsigned CombineSymbolTypes(unsigned T1, unsigned T2) { + unsigned TypeOrdering[] = {ELF::STT_NOTYPE, ELF::STT_OBJECT, ELF::STT_FUNC, + ELF::STT_GNU_IFUNC, ELF::STT_TLS}; + for (unsigned i = 0; i != array_lengthof(TypeOrdering); ++i) { + if (T1 == TypeOrdering[i]) + return T2; + if (T2 == TypeOrdering[i]) + return T1; + } + + return T2; +} + void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) { // Indirect symbols are handled differently, to match how 'as' handles @@ -187,27 +208,34 @@ void MCELFStreamer::EmitSymbolAttribute(MCSymbol *Symbol, break; case MCSA_ELF_TypeFunction: - MCELF::SetType(SD, ELF::STT_FUNC); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_FUNC)); break; case MCSA_ELF_TypeIndFunction: - MCELF::SetType(SD, ELF::STT_GNU_IFUNC); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_GNU_IFUNC)); break; case MCSA_ELF_TypeObject: - MCELF::SetType(SD, ELF::STT_OBJECT); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_OBJECT)); break; case MCSA_ELF_TypeTLS: - MCELF::SetType(SD, ELF::STT_TLS); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_TLS)); break; case MCSA_ELF_TypeCommon: - MCELF::SetType(SD, ELF::STT_COMMON); + // TODO: Emit these as a common symbol. + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_OBJECT)); break; case MCSA_ELF_TypeNoType: - MCELF::SetType(SD, ELF::STT_NOTYPE); + MCELF::SetType(SD, CombineSymbolTypes(MCELF::GetType(SD), + ELF::STT_NOTYPE)); break; case MCSA_Protected: |