From 0324b67267a7a08e88d9651b3c319df44fd5ae58 Mon Sep 17 00:00:00 2001 From: "Michael J. Spencer" Date: Fri, 21 Jan 2011 02:27:02 +0000 Subject: Object: Fix type punned pointer issues by making DataRefImpl a union and using intptr_t. llvm-svn: 123962 --- llvm/lib/Object/ELFObjectFile.cpp | 100 +++++++++++++++----------------------- 1 file changed, 40 insertions(+), 60 deletions(-) (limited to 'llvm/lib/Object/ELFObjectFile.cpp') diff --git a/llvm/lib/Object/ELFObjectFile.cpp b/llvm/lib/Object/ELFObjectFile.cpp index 8a232d5214f..682be770f48 100644 --- a/llvm/lib/Object/ELFObjectFile.cpp +++ b/llvm/lib/Object/ELFObjectFile.cpp @@ -128,8 +128,7 @@ struct Elf_Shdr_Impl : Elf_Shdr_Base { unsigned getEntityCount() const { if (sh_entsize == 0) return 0; - else - return sh_size / sh_entsize; + return sh_size / sh_entsize; } }; } @@ -176,14 +175,6 @@ struct Elf_Sym_Impl : Elf_Sym_Base { }; } -namespace { -struct ELFDataRefImpl { - uint32_t SymbolIndex; - uint16_t SymbolTableSectionIndex; - uint16_t Unused; -}; -} - namespace { template class ELFObjectFile : public ObjectFile { @@ -261,10 +252,8 @@ public: template void ELFObjectFile ::validateSymbol(DataRefImpl Symb) const { - const ELFDataRefImpl SymbolData = *reinterpret_cast(&Symb); const Elf_Sym *symb = getSymbol(Symb); - const Elf_Shdr *SymbolTableSection = - SymbolTableSections[SymbolData.SymbolTableSectionIndex]; + const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b]; // FIXME: We really need to do proper error handling in the case of an invalid // input file. Because we don't use exceptions, I think we'll just pass // an error object around. @@ -283,20 +272,18 @@ template SymbolRef ELFObjectFile ::getSymbolNext(DataRefImpl Symb) const { validateSymbol(Symb); - ELFDataRefImpl &SymbolData = *reinterpret_cast(&Symb); - const Elf_Shdr *SymbolTableSection = - SymbolTableSections[SymbolData.SymbolTableSectionIndex]; + const Elf_Shdr *SymbolTableSection = SymbolTableSections[Symb.d.b]; - ++SymbolData.SymbolIndex; + ++Symb.d.a; // Check to see if we are at the end of this symbol table. - if (SymbolData.SymbolIndex >= SymbolTableSection->getEntityCount()) { + if (Symb.d.a >= 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. + ++Symb.d.b; + Symb.d.a = 1; // The 0th symbol in ELF is fake. // Otherwise return the terminator. - if (SymbolData.SymbolTableSectionIndex >= SymbolTableSections.size()) { - SymbolData.SymbolIndex = std::numeric_limits::max(); - SymbolData.SymbolTableSectionIndex = std::numeric_limits::max(); + if (Symb.d.b >= SymbolTableSections.size()) { + Symb.d.a = std::numeric_limits::max(); + Symb.d.b = std::numeric_limits::max(); } } @@ -426,40 +413,37 @@ bool ELFObjectFile template SectionRef ELFObjectFile ::getSectionNext(DataRefImpl Sec) const { - const uint8_t *sec = *reinterpret_cast(&Sec); + const uint8_t *sec = reinterpret_cast(Sec.p); sec += Header->e_shentsize; - return SectionRef(DataRefImpl(sec), this); + Sec.p = reinterpret_cast(sec); + return SectionRef(Sec, this); } template StringRef ELFObjectFile ::getSectionName(DataRefImpl Sec) const { - const Elf_Shdr *sec = - *reinterpret_cast(&Sec); + const Elf_Shdr *sec = reinterpret_cast(Sec.p); return StringRef(getString(dot_shstrtab_sec, sec->sh_name)); } template uint64_t ELFObjectFile ::getSectionAddress(DataRefImpl Sec) const { - const Elf_Shdr *sec = - *reinterpret_cast(&Sec); + const Elf_Shdr *sec = reinterpret_cast(Sec.p); return sec->sh_addr; } template uint64_t ELFObjectFile ::getSectionSize(DataRefImpl Sec) const { - const Elf_Shdr *sec = - *reinterpret_cast(&Sec); + const Elf_Shdr *sec = reinterpret_cast(Sec.p); return sec->sh_size; } template StringRef ELFObjectFile ::getSectionContents(DataRefImpl Sec) const { - const Elf_Shdr *sec = - *reinterpret_cast(&Sec); + const Elf_Shdr *sec = reinterpret_cast(Sec.p); const char *start = (char*)base + sec->sh_offset; return StringRef(start, sec->sh_size); } @@ -467,8 +451,7 @@ StringRef ELFObjectFile template bool ELFObjectFile ::isSectionText(DataRefImpl Sec) const { - const Elf_Shdr *sec = - *reinterpret_cast(&Sec); + const Elf_Shdr *sec = reinterpret_cast(Sec.p); if (sec->sh_flags & ELF::SHF_EXECINSTR) return true; return false; @@ -538,49 +521,49 @@ ELFObjectFile::ELFObjectFile(MemoryBuffer *Object) template ObjectFile::symbol_iterator ELFObjectFile ::begin_symbols() const { - ELFDataRefImpl SymbolData; + DataRefImpl SymbolData; memset(&SymbolData, 0, sizeof(SymbolData)); if (SymbolTableSections.size() == 0) { - SymbolData.SymbolIndex = std::numeric_limits::max(); - SymbolData.SymbolTableSectionIndex = std::numeric_limits::max(); + SymbolData.d.a = std::numeric_limits::max(); + SymbolData.d.b = std::numeric_limits::max(); } else { - SymbolData.SymbolIndex = 1; // The 0th symbol in ELF is fake. - SymbolData.SymbolTableSectionIndex = 0; + SymbolData.d.a = 1; // The 0th symbol in ELF is fake. + SymbolData.d.b = 0; } - return symbol_iterator( - SymbolRef(DataRefImpl(*reinterpret_cast(&SymbolData)), this)); + return symbol_iterator(SymbolRef(SymbolData, this)); } template ObjectFile::symbol_iterator ELFObjectFile ::end_symbols() const { - ELFDataRefImpl SymbolData; + DataRefImpl SymbolData; memset(&SymbolData, 0, sizeof(SymbolData)); - SymbolData.SymbolIndex = std::numeric_limits::max(); - SymbolData.SymbolTableSectionIndex = std::numeric_limits::max(); - return symbol_iterator( - SymbolRef(DataRefImpl(*reinterpret_cast(&SymbolData)), this)); + SymbolData.d.a = std::numeric_limits::max(); + SymbolData.d.b = std::numeric_limits::max(); + return symbol_iterator(SymbolRef(SymbolData, this)); } template ObjectFile::section_iterator ELFObjectFile ::begin_sections() const { - return section_iterator( - SectionRef(DataRefImpl(base + Header->e_shoff), this)); + DataRefImpl ret; + ret.p = reinterpret_cast(base + Header->e_shoff); + return section_iterator(SectionRef(ret, this)); } template ObjectFile::section_iterator ELFObjectFile ::end_sections() const { - return section_iterator( - SectionRef(DataRefImpl(base - + Header->e_shoff - + (Header->e_shentsize * Header->e_shnum)), this)); + DataRefImpl ret; + ret.p = reinterpret_cast(base + + Header->e_shoff + + (Header->e_shentsize * Header->e_shnum)); + return section_iterator(SectionRef(ret, this)); } template uint8_t ELFObjectFile::getBytesInAddress() const { - return 4; + return is64Bits ? 8 : 4; } template @@ -626,20 +609,17 @@ unsigned ELFObjectFile::getArch() const { template const typename ELFObjectFile::Elf_Sym * ELFObjectFile::getSymbol(DataRefImpl Symb) const { - const ELFDataRefImpl SymbolData = *reinterpret_cast(&Symb); - const Elf_Shdr *sec = - SymbolTableSections[SymbolData.SymbolTableSectionIndex]; + const Elf_Shdr *sec = SymbolTableSections[Symb.d.b]; return reinterpret_cast( base + sec->sh_offset - + (SymbolData.SymbolIndex * sec->sh_entsize)); + + (Symb.d.a * sec->sh_entsize)); } template const typename ELFObjectFile::Elf_Shdr * ELFObjectFile::getSection(DataRefImpl Symb) const { - const ELFDataRefImpl SymbolData = *reinterpret_cast(&Symb); - const Elf_Shdr *sec = getSection(SymbolData.SymbolTableSectionIndex); + const Elf_Shdr *sec = getSection(Symb.d.b); if (sec->sh_type != ELF::SHT_SYMTAB) // FIXME: Proper error handling. report_fatal_error("Invalid symbol table section!"); -- cgit v1.2.3