From 72580780a98cb8b0019b7ec4ed88e3f3328b9969 Mon Sep 17 00:00:00 2001 From: Joerg Sonnenberger Date: Tue, 29 Oct 2013 01:06:17 +0000 Subject: Move the STT_FILE symbols out of the normal symbol table processing for ELF. They can overlap with the other symbols, e.g. if a source file "foo.c" contains a function "foo" with a static variable "c". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193569 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/MC/ELFObjectWriter.cpp | 34 ++++++++++++++++++++++++++-------- lib/MC/MCELF.cpp | 7 +++---- lib/MC/MCELFStreamer.cpp | 14 ++++---------- 3 files changed, 33 insertions(+), 22 deletions(-) (limited to 'lib/MC') diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index eb197f2..9899bb2 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -73,10 +73,6 @@ class ELFObjectWriter : public MCObjectWriter { // Support lexicographic sorting. bool operator<(const ELFSymbolData &RHS) const { - if (MCELF::GetType(*SymbolData) == ELF::STT_FILE) - return true; - if (MCELF::GetType(*RHS.SymbolData) == ELF::STT_FILE) - return false; return SymbolData->getSymbol().getName() < RHS.SymbolData->getSymbol().getName(); } @@ -98,6 +94,7 @@ class ELFObjectWriter : public MCObjectWriter { /// @{ SmallString<256> StringTable; + std::vector FileSymbolData; std::vector LocalSymbolData; std::vector ExternalSymbolData; std::vector UndefinedSymbolData; @@ -551,7 +548,7 @@ void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF, uint8_t Type = MCELF::GetType(Data); uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift); - // Other and Visibility share the same byte with Visability using the lower + // Other and Visibility share the same byte with Visibility using the lower // 2 bits uint8_t Visibility = MCELF::GetVisibility(OrigData); uint8_t Other = MCELF::getOther(OrigData) << @@ -590,8 +587,15 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, // The first entry is the undefined symbol entry. WriteSymbolEntry(SymtabF, ShndxF, 0, 0, 0, 0, 0, 0, false); + for (unsigned i = 0, e = FileSymbolData.size(); i != e; ++i) { + WriteSymbolEntry(SymtabF, ShndxF, FileSymbolData[i], + ELF::STT_FILE | ELF::STB_LOCAL, 0, 0, + ELF::STV_DEFAULT, ELF::SHN_ABS, true); + } + // Write the symbol table entries. - LastLocalSymbolIndex = LocalSymbolData.size() + 1; + LastLocalSymbolIndex = FileSymbolData.size() + LocalSymbolData.size() + 1; + for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) { ELFSymbolData &MSD = LocalSymbolData[i]; WriteSymbol(SymtabF, ShndxF, MSD, Layout); @@ -880,6 +884,20 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, // FIXME: We could optimize suffixes in strtab in the same way we // optimize them in shstrtab. + for (MCAssembler::const_file_name_iterator it = Asm.file_names_begin(), + ie = Asm.file_names_end(); + it != ie; + ++it) { + StringRef Name = *it; + uint64_t &Entry = StringIndexMap[Name]; + if (!Entry) { + Entry = StringTable.size(); + StringTable += Name; + StringTable += '\x00'; + } + FileSymbolData.push_back(Entry); + } + // Add the data for the symbols. for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), ie = Asm.symbol_end(); it != ie; ++it) { @@ -964,7 +982,7 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, // Set the symbol indices. Local symbols must come before all other // symbols with non-local bindings. - unsigned Index = 1; + unsigned Index = FileSymbolData.size() + 1; for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) LocalSymbolData[i].SymbolData->setIndex(Index++); @@ -1073,7 +1091,7 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm, else if (entry.Index < 0) entry.Index = getSymbolIndexInSymbolTable(Asm, entry.Symbol); else - entry.Index += LocalSymbolData.size(); + entry.Index += FileSymbolData.size() + LocalSymbolData.size(); if (is64Bit()) { String64(*F, entry.r_offset); if (TargetObjectWriter->isN64()) { diff --git a/lib/MC/MCELF.cpp b/lib/MC/MCELF.cpp index 560cdbc..ebb189e 100644 --- a/lib/MC/MCELF.cpp +++ b/lib/MC/MCELF.cpp @@ -36,8 +36,8 @@ unsigned MCELF::GetBinding(const MCSymbolData &SD) { void MCELF::SetType(MCSymbolData &SD, unsigned Type) { assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT || Type == ELF::STT_FUNC || Type == ELF::STT_SECTION || - Type == ELF::STT_FILE || Type == ELF::STT_COMMON || - Type == ELF::STT_TLS || Type == ELF::STT_GNU_IFUNC); + Type == ELF::STT_COMMON || Type == ELF::STT_TLS || + Type == ELF::STT_GNU_IFUNC); uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STT_Shift); SD.setFlags(OtherFlags | (Type << ELF_STT_Shift)); @@ -47,8 +47,7 @@ unsigned MCELF::GetType(const MCSymbolData &SD) { uint32_t Type = (SD.getFlags() & (0xf << ELF_STT_Shift)) >> ELF_STT_Shift; assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT || Type == ELF::STT_FUNC || Type == ELF::STT_SECTION || - Type == ELF::STT_FILE || Type == ELF::STT_COMMON || - Type == ELF::STT_TLS || Type == ELF::STT_GNU_IFUNC); + Type == ELF::STT_COMMON || Type == ELF::STT_TLS || Type == ELF::STT_GNU_IFUNC); return Type; } diff --git a/lib/MC/MCELFStreamer.cpp b/lib/MC/MCELFStreamer.cpp index 3f6c62c..3be71ce 100644 --- a/lib/MC/MCELFStreamer.cpp +++ b/lib/MC/MCELFStreamer.cpp @@ -316,17 +316,11 @@ void MCELFStreamer::EmitValueToAlignment(unsigned ByteAlignment, ValueSize, MaxBytesToEmit); } - -// Add a symbol for the file name of this module. This is the second -// entry in the module's symbol table (the first being the null symbol). +// Add a symbol for the file name of this module. They start after the +// null symbol and don't count as normal symbol, i.e. a non-STT_FILE symbol +// with the same name may appear. void MCELFStreamer::EmitFileDirective(StringRef Filename) { - MCSymbol *Symbol = getAssembler().getContext().GetOrCreateSymbol(Filename); - Symbol->setSection(*getCurrentSection().first); - Symbol->setAbsolute(); - - MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol); - - SD.setFlags(ELF_STT_File | ELF_STB_Local | ELF_STV_Default); + getAssembler().addFileName(Filename); } void MCELFStreamer::EmitIdent(StringRef IdentString) { -- cgit v1.1