void SVMELFProgramWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { // First pass, allocate all non-debug sections and compute the // initial layout of the plaintext RWDATA segments. ML.AllocateSections(Asm, Layout); // Apply fixups that were stored in RecordRelocation ML.ApplyLateFixups(Asm, Layout); // Now we can know the final binary image of the RWDATA segments. Compress them. rwCompress(Asm, Layout, ML); ML.AllocateSections(Asm, Layout); if (ELFDebug) { // Allocate all debug sections last EMB.BuildSections(Asm, Layout, ML); ML.AllocateSections(Asm, Layout); } // Write header blocks writeELFHeader(Asm, Layout); for (int S = 0; S < SPS_DEBUG; ++S) writeProgramHeader((SVMProgramSection) S); // Write program data, sorted by SPS section int endS = ELFDebug ? SPS_NUM_SECTIONS : SPS_DEBUG; for (int S = 0; S < endS; ++S) { if (S == SPS_DEBUG) writeDebugMessage(); for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { const MCSectionData *SD = &*it; if (ML.getSectionKind(SD) != S) continue; if (Layout.getSectionFileSize(SD) == 0) continue; padToOffset(ML.getSectionDiskOffset(SD)); Asm.WriteSectionData(SD, Layout); } } if (ELFDebug) { // On debug binaries, generate section headers last padToOffset(SHOffset); // Dummy NULL section header (index 0) WriteZeros(sizeof(ELF::Elf32_Shdr)); for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { const MCSectionData *SD = &*it; writeSectionHeader(Layout, SD); } } }
void MachObjectWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { unsigned NumSections = Asm.size(); // The section data starts after the header, the segment load command (and // section headers) and the symbol table. unsigned NumLoadCommands = 1; uint64_t LoadCommandsSize = is64Bit() ? macho::SegmentLoadCommand64Size + NumSections * macho::Section64Size : macho::SegmentLoadCommand32Size + NumSections * macho::Section32Size; // Add the symbol table load command sizes, if used. unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() + UndefinedSymbolData.size(); if (NumSymbols) { NumLoadCommands += 2; LoadCommandsSize += (macho::SymtabLoadCommandSize + macho::DysymtabLoadCommandSize); } // Compute the total size of the section data, as well as its file size and vm // size. uint64_t SectionDataStart = (is64Bit() ? macho::Header64Size : macho::Header32Size) + LoadCommandsSize; uint64_t SectionDataSize = 0; uint64_t SectionDataFileSize = 0; uint64_t VMSize = 0; for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { const MCSectionData &SD = *it; uint64_t Address = getSectionAddress(&SD); uint64_t Size = Layout.getSectionAddressSize(&SD); uint64_t FileSize = Layout.getSectionFileSize(&SD); FileSize += getPaddingSize(&SD, Layout); VMSize = std::max(VMSize, Address + Size); if (SD.getSection().isVirtualSection()) continue; SectionDataSize = std::max(SectionDataSize, Address + Size); SectionDataFileSize = std::max(SectionDataFileSize, Address + FileSize); } // The section data is padded to 4 bytes. // // FIXME: Is this machine dependent? unsigned SectionDataPadding = OffsetToAlignment(SectionDataFileSize, 4); SectionDataFileSize += SectionDataPadding; // Write the prolog, starting with the header and load command... WriteHeader(NumLoadCommands, LoadCommandsSize, Asm.getSubsectionsViaSymbols()); WriteSegmentLoadCommand(NumSections, VMSize, SectionDataStart, SectionDataSize); // ... and then the section headers. uint64_t RelocTableEnd = SectionDataStart + SectionDataFileSize; for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { std::vector<macho::RelocationEntry> &Relocs = Relocations[it]; unsigned NumRelocs = Relocs.size(); uint64_t SectionStart = SectionDataStart + getSectionAddress(it); WriteSection(Asm, Layout, *it, SectionStart, RelocTableEnd, NumRelocs); RelocTableEnd += NumRelocs * macho::RelocationInfoSize; } // Write the symbol table load command, if used. if (NumSymbols) { unsigned FirstLocalSymbol = 0; unsigned NumLocalSymbols = LocalSymbolData.size(); unsigned FirstExternalSymbol = FirstLocalSymbol + NumLocalSymbols; unsigned NumExternalSymbols = ExternalSymbolData.size(); unsigned FirstUndefinedSymbol = FirstExternalSymbol + NumExternalSymbols; unsigned NumUndefinedSymbols = UndefinedSymbolData.size(); unsigned NumIndirectSymbols = Asm.indirect_symbol_size(); unsigned NumSymTabSymbols = NumLocalSymbols + NumExternalSymbols + NumUndefinedSymbols; uint64_t IndirectSymbolSize = NumIndirectSymbols * 4; uint64_t IndirectSymbolOffset = 0; // If used, the indirect symbols are written after the section data. if (NumIndirectSymbols) IndirectSymbolOffset = RelocTableEnd; // The symbol table is written after the indirect symbol data. uint64_t SymbolTableOffset = RelocTableEnd + IndirectSymbolSize; // The string table is written after symbol table. uint64_t StringTableOffset = SymbolTableOffset + NumSymTabSymbols * (is64Bit() ? macho::Nlist64Size : macho::Nlist32Size); WriteSymtabLoadCommand(SymbolTableOffset, NumSymTabSymbols, StringTableOffset, StringTable.size()); WriteDysymtabLoadCommand(FirstLocalSymbol, NumLocalSymbols, FirstExternalSymbol, NumExternalSymbols, FirstUndefinedSymbol, NumUndefinedSymbols, IndirectSymbolOffset, NumIndirectSymbols); } // Write the actual section data. for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { Asm.WriteSectionData(it, Layout); uint64_t Pad = getPaddingSize(it, Layout); for (unsigned int i = 0; i < Pad; ++i) Write8(0); } // Write the extra padding. WriteZeros(SectionDataPadding); // Write the relocation entries. 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). std::vector<macho::RelocationEntry> &Relocs = Relocations[it]; for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { Write32(Relocs[e - i - 1].Word0); Write32(Relocs[e - i - 1].Word1); } } // Write the symbol table data, if used. if (NumSymbols) { // Write the indirect symbol entries. 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 // special handling. const MCSectionMachO &Section = static_cast<const MCSectionMachO&>(it->SectionData->getSection()); if (Section.getType() == MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS) { // If this symbol is defined and internal, mark it as such. if (it->Symbol->isDefined() && !Asm.getSymbolData(*it->Symbol).isExternal()) { uint32_t Flags = macho::ISF_Local; if (it->Symbol->isAbsolute()) Flags |= macho::ISF_Absolute; Write32(Flags); continue; } } Write32(Asm.getSymbolData(*it->Symbol).getIndex()); } // FIXME: Check that offsets match computed ones. // Write the symbol table entries. for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) WriteNlist(LocalSymbolData[i], Layout); for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) WriteNlist(ExternalSymbolData[i], Layout); for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i) WriteNlist(UndefinedSymbolData[i], Layout); // Write the string table. OS << StringTable.str(); } }
void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { // Assign symbol and section indexes and offsets. Header.NumberOfSections = 0; for (sections::iterator i = Sections.begin(), e = Sections.end(); i != e; i++) { if (Layout.getSectionAddressSize((*i)->MCData) > 0) { MakeSectionReal(**i, ++Header.NumberOfSections); } else { (*i)->Number = -1; } } Header.NumberOfSymbols = 0; for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) { COFFSymbol *coff_symbol = *i; MCSymbolData const *SymbolData = coff_symbol->MCData; // Update section number & offset for symbols that have them. if ((SymbolData != NULL) && (SymbolData->Fragment != NULL)) { assert(coff_symbol->Section != NULL); coff_symbol->Data.SectionNumber = coff_symbol->Section->Number; coff_symbol->Data.Value = Layout.getFragmentOffset(SymbolData->Fragment) + SymbolData->Offset; } if (coff_symbol->should_keep()) { MakeSymbolReal(*coff_symbol, Header.NumberOfSymbols++); // Update auxiliary symbol info. coff_symbol->Data.NumberOfAuxSymbols = coff_symbol->Aux.size(); Header.NumberOfSymbols += coff_symbol->Data.NumberOfAuxSymbols; } else coff_symbol->Index = -1; } // Fixup weak external references. for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) { COFFSymbol *coff_symbol = *i; if (coff_symbol->Other != NULL) { assert(coff_symbol->Index != -1); assert(coff_symbol->Aux.size() == 1 && "Symbol must contain one aux symbol!"); assert(coff_symbol->Aux[0].AuxType == ATWeakExternal && "Symbol's aux symbol must be a Weak External!"); coff_symbol->Aux[0].Aux.WeakExternal.TagIndex = coff_symbol->Other->Index; } } // Assign file offsets to COFF object file structures. unsigned offset = 0; offset += COFF::HeaderSize; offset += COFF::SectionSize * Header.NumberOfSections; for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; i++) { COFFSection *Sec = SectionMap[&i->getSection()]; if (Sec->Number == -1) continue; Sec->Header.SizeOfRawData = Layout.getSectionAddressSize(i); if (IsPhysicalSection(Sec)) { Sec->Header.PointerToRawData = offset; offset += Sec->Header.SizeOfRawData; } if (Sec->Relocations.size() > 0) { Sec->Header.NumberOfRelocations = Sec->Relocations.size(); Sec->Header.PointerToRelocations = offset; offset += COFF::RelocationSize * Sec->Relocations.size(); for (relocations::iterator cr = Sec->Relocations.begin(), er = Sec->Relocations.end(); cr != er; ++cr) { assert((*cr).Symb->Index != -1); (*cr).Data.SymbolTableIndex = (*cr).Symb->Index; } } assert(Sec->Symbol->Aux.size() == 1 && "Section's symbol must have one aux!"); AuxSymbol &Aux = Sec->Symbol->Aux[0]; assert(Aux.AuxType == ATSectionDefinition && "Section's symbol's aux symbol must be a Section Definition!"); Aux.Aux.SectionDefinition.Length = Sec->Header.SizeOfRawData; Aux.Aux.SectionDefinition.NumberOfRelocations = Sec->Header.NumberOfRelocations; Aux.Aux.SectionDefinition.NumberOfLinenumbers = Sec->Header.NumberOfLineNumbers; } Header.PointerToSymbolTable = offset; Header.TimeDateStamp = sys::TimeValue::now().toEpochTime(); // Write it all to disk... WriteFileHeader(Header); { sections::iterator i, ie; MCAssembler::const_iterator j, je; for (i = Sections.begin(), ie = Sections.end(); i != ie; i++) if ((*i)->Number != -1) WriteSectionHeader((*i)->Header); for (i = Sections.begin(), ie = Sections.end(), j = Asm.begin(), je = Asm.end(); (i != ie) && (j != je); ++i, ++j) { if ((*i)->Number == -1) continue; if ((*i)->Header.PointerToRawData != 0) { assert(OS.tell() == (*i)->Header.PointerToRawData && "Section::PointerToRawData is insane!"); Asm.WriteSectionData(j, Layout, this); } if ((*i)->Relocations.size() > 0) { assert(OS.tell() == (*i)->Header.PointerToRelocations && "Section::PointerToRelocations is insane!"); for (relocations::const_iterator k = (*i)->Relocations.begin(), ke = (*i)->Relocations.end(); k != ke; k++) { WriteRelocation(k->Data); } } else assert((*i)->Header.PointerToRelocations == 0 && "Section::PointerToRelocations is insane!"); } } assert(OS.tell() == Header.PointerToSymbolTable && "Header::PointerToSymbolTable is insane!"); for (symbols::iterator i = Symbols.begin(), e = Symbols.end(); i != e; i++) if ((*i)->Index != -1) WriteSymbol(*i); OS.write((char const *)&Strings.Data.front(), Strings.Data.size()); }