[llvm-commits] [llvm] r123896 - in /llvm/trunk: include/llvm/Support/ELF.h lib/Object/CMakeLists.txt lib/Object/ELFObjectFile.cpp lib/Object/ObjectFile.cpp

[NAKAMURA Takumi]

Michael,


2011/1/20 Michael J. Spencer <bigcheesegs at gmail.com>:
> Author: mspencer
> Date: Thu Jan 20 00:38:47 2011
> New Revision: 123896

> --- llvm/trunk/lib/Object/ELFObjectFile.cpp (added)
> +++ llvm/trunk/lib/Object/ELFObjectFile.cpp Thu Jan 20 00:38:47 2011

> +template<support::endianness target_endianness, bool is64Bits>
> +SymbolRef ELFObjectFile<target_endianness, is64Bits>
> +                       ::getSymbolNext(DataRefImpl Symb) const {
> +  validateSymbol(Symb);
> +  ELFDataRefImpl &SymbolData = *reinterpret_cast<ELFDataRefImpl *>(&Symb);
> +  const Elf_Shdr *SymbolTableSection =
> +    SymbolTableSections[SymbolData.SymbolTableSectionIndex];
> +
> +  ++SymbolData.SymbolIndex;
> +  // Check to see if we are at the end of this symbol table.
> +  if (SymbolData.SymbolIndex >= SymbolTableSection->getEntityCount()) {
> +    // We are at the end. If there are other symbol tables, jump to them.
> +    ++SymbolData.SymbolTableSectionIndex;
> +    SymbolData.SymbolIndex = 1; // The 0th symbol in ELF is fake.
> +    // Otherwise return the terminator.
> +    if (SymbolData.SymbolTableSectionIndex >= SymbolTableSections.size()) {
> +      SymbolData.SymbolIndex = std::numeric_limits<uint32_t>::max();
> +      SymbolData.SymbolTableSectionIndex = std::numeric_limits<uint32_t>::max();
> +    }
> +  }
> +
> +  return SymbolRef(Symb, this);
> +}

It breaks "strict aliasing".
(DataRefImpl)Symb would not be updated with g++-4.4.0 -O3 (includes
-fstrict-aliasing).
For me, "llvm-nm
test/Object/TestObjectFiles/trivial-object-test.elf-i386" hangs up
with infinite loop.


...Takumi