From d84d196a86630d67d32e7bf29f47606de3c504ba Mon Sep 17 00:00:00 2001 From: Daniel Dunbar Date: Fri, 19 Mar 2010 07:09:33 +0000 Subject: [PATCH] MC/Mach-O: Factor out ExecutePostLayoutBinding, to separate the post-layout changes the object writer may need to make to the assembler from the actual .o writing. llvm-svn: 98943 --- llvm/include/llvm/MC/MCAssembler.h | 8 ++++ llvm/lib/MC/MCAssembler.cpp | 64 +++++++++++++++--------------- 2 files changed, 41 insertions(+), 31 deletions(-) diff --git a/llvm/include/llvm/MC/MCAssembler.h b/llvm/include/llvm/MC/MCAssembler.h index 4a2a8bf17239..0c1d810bf97d 100644 --- a/llvm/include/llvm/MC/MCAssembler.h +++ b/llvm/include/llvm/MC/MCAssembler.h @@ -590,6 +590,8 @@ public: typedef SymbolDataListType::const_iterator const_symbol_iterator; typedef SymbolDataListType::iterator symbol_iterator; + typedef std::vector::const_iterator + const_indirect_symbol_iterator; typedef std::vector::iterator indirect_symbol_iterator; private: @@ -742,10 +744,16 @@ public: indirect_symbol_iterator indirect_symbol_begin() { return IndirectSymbols.begin(); } + const_indirect_symbol_iterator indirect_symbol_begin() const { + return IndirectSymbols.begin(); + } indirect_symbol_iterator indirect_symbol_end() { return IndirectSymbols.end(); } + const_indirect_symbol_iterator indirect_symbol_end() const { + return IndirectSymbols.end(); + } size_t indirect_symbol_size() const { return IndirectSymbols.size(); } diff --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp index 7b4512e7d4e7..c18a3a64ce7d 100644 --- a/llvm/lib/MC/MCAssembler.cpp +++ b/llvm/lib/MC/MCAssembler.cpp @@ -778,23 +778,28 @@ public: StringTable += '\x00'; } - void WriteObject(MCAssembler &Asm) { - unsigned NumSections = Asm.size(); - + void ExecutePostLayoutBinding(MCAssembler &Asm) { // Create symbol data for any indirect symbols. BindIndirectSymbols(Asm); - // Compute symbol table information. - SmallString<256> StringTable; - std::vector LocalSymbolData; - std::vector ExternalSymbolData; - std::vector UndefinedSymbolData; - unsigned NumSymbols = Asm.symbol_size(); + // Compute symbol table information and bind symbol indices. + ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData, + UndefinedSymbolData); - // No symbol table command is written if there are no symbols. - if (NumSymbols) - ComputeSymbolTable(Asm, StringTable, LocalSymbolData, ExternalSymbolData, - UndefinedSymbolData); + // Compute relocations. + for (MCAssembler::iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + MCSectionData &SD = *it; + for (MCSectionData::iterator it2 = SD.begin(), + ie2 = SD.end(); it2 != ie2; ++it2) + if (MCDataFragment *DF = dyn_cast(&*it2)) + for (unsigned i = 0, e = DF->fixup_size(); i != e; ++i) + ComputeRelocationInfo(Asm, *DF, DF->getFixups()[i]); + } + } + + void WriteObject(const MCAssembler &Asm) { + unsigned NumSections = Asm.size(); // The section data starts after the header, the segment load command (and // section headers) and the symbol table. @@ -804,6 +809,8 @@ public: SegmentLoadCommand32Size + NumSections * Section32Size; // Add the symbol table load command sizes, if used. + unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() + + UndefinedSymbolData.size(); if (NumSymbols) { NumLoadCommands += 2; LoadCommandsSize += SymtabLoadCommandSize + DysymtabLoadCommandSize; @@ -816,9 +823,9 @@ public: uint64_t SectionDataSize = 0; uint64_t SectionDataFileSize = 0; uint64_t VMSize = 0; - for (MCAssembler::iterator it = Asm.begin(), + for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { - MCSectionData &SD = *it; + const MCSectionData &SD = *it; VMSize = std::max(VMSize, SD.getAddress() + SD.getSize()); @@ -843,19 +850,9 @@ public: WriteSegmentLoadCommand(NumSections, VMSize, SectionDataStart, SectionDataSize); - for (MCAssembler::iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - MCSectionData &SD = *it; - for (MCSectionData::iterator it2 = SD.begin(), - ie2 = SD.end(); it2 != ie2; ++it2) - if (MCDataFragment *DF = dyn_cast(&*it2)) - for (unsigned i = 0, e = DF->fixup_size(); i != e; ++i) - ComputeRelocationInfo(Asm, *DF, DF->getFixups()[i]); - } - // ... and then the section headers. uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize; - for (MCAssembler::iterator it = Asm.begin(), + for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { std::vector &Relocs = Relocations[it]; unsigned NumRelocs = Relocs.size(); @@ -899,14 +896,15 @@ public: } // Write the actual section data. - for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) + for (MCAssembler::const_iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) WriteFileData(OS, *it, *this); // Write the extra padding. WriteZeros(SectionDataPadding); // Write the relocation entries. - for (MCAssembler::iterator it = Asm.begin(), + for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { // Write the section relocation entries, in reverse order to match 'as' // (approximately, the exact algorithm is more complicated than this). @@ -920,7 +918,7 @@ public: // Write the symbol table data, if used. if (NumSymbols) { // Write the indirect symbol entries. - for (MCAssembler::indirect_symbol_iterator + for (MCAssembler::const_indirect_symbol_iterator it = Asm.indirect_symbol_begin(), ie = Asm.indirect_symbol_end(); it != ie; ++it) { // Indirect symbols in the non lazy symbol pointer section have some @@ -1478,11 +1476,15 @@ void MCAssembler::Finish() { llvm::errs() << "assembler backend - post-layout\n--\n"; dump(); }); - // Write the object file. - // // FIXME: Factor out MCObjectWriter. bool Is64Bit = StringRef(getBackend().getTarget().getName()) == "x86-64"; MachObjectWriter MOW(OS, Is64Bit); + + // Allow the object writer a chance to perform post-layout binding (for + // example, to set the index fields in the symbol data). + MOW.ExecutePostLayoutBinding(*this); + + // Write the object file. MOW.WriteObject(*this); OS.flush();