X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMachObjectWriter.cpp;h=95b92485eb63519752e5071e2b8971bae7ceeba4;hb=0e9c68e6bc8768143308b0162e900ba8bd10dc01;hp=b3b593d3154be1bfa30fedaa38d0bf5c578f4b35;hpb=3b8cc2299ba497e7c774622f6770403a0e970494;p=oota-llvm.git diff --git a/lib/MC/MachObjectWriter.cpp b/lib/MC/MachObjectWriter.cpp index b3b593d3154..95b92485eb6 100644 --- a/lib/MC/MachObjectWriter.cpp +++ b/lib/MC/MachObjectWriter.cpp @@ -26,6 +26,8 @@ #include using namespace llvm; +#define DEBUG_TYPE "mc" + void MachObjectWriter::reset() { Relocations.clear(); IndirectSymBase.clear(); @@ -82,7 +84,7 @@ uint64_t MachObjectWriter::getSymbolAddress(const MCSymbolData* SD, MCValue Target; - if (!S.getVariableValue()->EvaluateAsRelocatable(Target, &Layout)) + if (!S.getVariableValue()->EvaluateAsRelocatable(Target, &Layout, nullptr)) report_fatal_error("unable to evaluate offset for variable '" + S.getName() + "'"); @@ -301,20 +303,50 @@ void MachObjectWriter::WriteDysymtabLoadCommand(uint32_t FirstLocalSymbol, assert(OS.tell() - Start == sizeof(MachO::dysymtab_command)); } +MachObjectWriter::MachSymbolData * +MachObjectWriter::findSymbolData(const MCSymbol &Sym) { + for (auto &Entry : LocalSymbolData) + if (&Entry.SymbolData->getSymbol() == &Sym) + return &Entry; + + for (auto &Entry : ExternalSymbolData) + if (&Entry.SymbolData->getSymbol() == &Sym) + return &Entry; + + for (auto &Entry : UndefinedSymbolData) + if (&Entry.SymbolData->getSymbol() == &Sym) + return &Entry; + + return nullptr; +} + void MachObjectWriter::WriteNlist(MachSymbolData &MSD, const MCAsmLayout &Layout) { MCSymbolData &Data = *MSD.SymbolData; - const MCSymbol &Symbol = Data.getSymbol(); + const MCSymbol *Symbol = &Data.getSymbol(); + const MCSymbol *AliasedSymbol = &Symbol->AliasedSymbol(); + uint8_t SectionIndex = MSD.SectionIndex; uint8_t Type = 0; uint16_t Flags = Data.getFlags(); uint64_t Address = 0; + bool IsAlias = Symbol != AliasedSymbol; + + MachSymbolData *AliaseeInfo; + if (IsAlias) { + AliaseeInfo = findSymbolData(*AliasedSymbol); + if (AliaseeInfo) + SectionIndex = AliaseeInfo->SectionIndex; + Symbol = AliasedSymbol; + } // Set the N_TYPE bits. See . // // FIXME: Are the prebound or indirect fields possible here? - if (Symbol.isUndefined()) + if (IsAlias && Symbol->isUndefined()) + Type = MachO::N_INDR; + else if (Symbol->isUndefined()) Type = MachO::N_UNDF; - else if (Symbol.isAbsolute()) + else if (Symbol->isAbsolute()) Type = MachO::N_ABS; else Type = MachO::N_SECT; @@ -325,13 +357,15 @@ void MachObjectWriter::WriteNlist(MachSymbolData &MSD, Type |= MachO::N_PEXT; // Set external bit. - if (Data.isExternal() || Symbol.isUndefined()) + if (Data.isExternal() || (!IsAlias && Symbol->isUndefined())) Type |= MachO::N_EXT; // Compute the symbol address. - if (Symbol.isDefined()) { + if (IsAlias && Symbol->isUndefined()) + Address = AliaseeInfo->StringIndex; + else if (Symbol->isDefined()) Address = getSymbolAddress(&Data, Layout); - } else if (Data.isCommon()) { + else if (Data.isCommon()) { // Common symbols are encoded with the size in the address // field, and their alignment in the flags. Address = Data.getCommonSize(); @@ -342,18 +376,21 @@ void MachObjectWriter::WriteNlist(MachSymbolData &MSD, assert((1U << Log2Size) == Align && "Invalid 'common' alignment!"); if (Log2Size > 15) report_fatal_error("invalid 'common' alignment '" + - Twine(Align) + "' for '" + Symbol.getName() + "'", + Twine(Align) + "' for '" + Symbol->getName() + "'", false); // FIXME: Keep this mask with the SymbolFlags enumeration. Flags = (Flags & 0xF0FF) | (Log2Size << 8); } } + if (Layout.getAssembler().isThumbFunc(Symbol)) + Flags |= SF_ThumbFunc; + // struct nlist (12 bytes) Write32(MSD.StringIndex); Write8(Type); - Write8(MSD.SectionIndex); + Write8(SectionIndex); // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc' // value. @@ -417,6 +454,7 @@ void MachObjectWriter::RecordRelocation(const MCAssembler &Asm, const MCFragment *Fragment, const MCFixup &Fixup, MCValue Target, + bool &IsPCRel, uint64_t &FixedValue) { TargetObjectWriter->RecordRelocation(this, Asm, Layout, Fragment, Fixup, Target, FixedValue); @@ -515,15 +553,14 @@ ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable, // table, then sort the symbols is chosen to match 'as'. Even though it // doesn't matter for correctness, this is important for letting us diff .o // files. - for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), - ie = Asm.symbol_end(); it != ie; ++it) { - const MCSymbol &Symbol = it->getSymbol(); + for (MCSymbolData &SD : Asm.symbols()) { + const MCSymbol &Symbol = SD.getSymbol(); // Ignore non-linker visible symbols. - if (!Asm.isSymbolLinkerVisible(it->getSymbol())) + if (!Asm.isSymbolLinkerVisible(SD.getSymbol())) continue; - if (!it->isExternal() && !Symbol.isUndefined()) + if (!SD.isExternal() && !Symbol.isUndefined()) continue; uint64_t &Entry = StringIndexMap[Symbol.getName()]; @@ -534,7 +571,7 @@ ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable, } MachSymbolData MSD; - MSD.SymbolData = it; + MSD.SymbolData = &SD; MSD.StringIndex = Entry; if (Symbol.isUndefined()) { @@ -551,15 +588,14 @@ ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable, } // Now add the data for local symbols. - for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), - ie = Asm.symbol_end(); it != ie; ++it) { - const MCSymbol &Symbol = it->getSymbol(); + for (MCSymbolData &SD : Asm.symbols()) { + const MCSymbol &Symbol = SD.getSymbol(); // Ignore non-linker visible symbols. - if (!Asm.isSymbolLinkerVisible(it->getSymbol())) + if (!Asm.isSymbolLinkerVisible(SD.getSymbol())) continue; - if (it->isExternal() || Symbol.isUndefined()) + if (SD.isExternal() || Symbol.isUndefined()) continue; uint64_t &Entry = StringIndexMap[Symbol.getName()]; @@ -570,7 +606,7 @@ ComputeSymbolTable(MCAssembler &Asm, SmallString<256> &StringTable, } MachSymbolData MSD; - MSD.SymbolData = it; + MSD.SymbolData = &SD; MSD.StringIndex = Entry; if (Symbol.isAbsolute()) { @@ -620,10 +656,7 @@ void MachObjectWriter::computeSectionAddresses(const MCAssembler &Asm, void MachObjectWriter::markAbsoluteVariableSymbols(MCAssembler &Asm, const MCAsmLayout &Layout) { - for (MCAssembler::symbol_iterator i = Asm.symbol_begin(), - e = Asm.symbol_end(); - i != e; ++i) { - MCSymbolData &SD = *i; + for (MCSymbolData &SD : Asm.symbols()) { if (!SD.getSymbol().isVariable()) continue; @@ -631,7 +664,7 @@ void MachObjectWriter::markAbsoluteVariableSymbols(MCAssembler &Asm, // and neither symbol is external, mark the variable as absolute. const MCExpr *Expr = SD.getSymbol().getVariableValue(); MCValue Value; - if (Expr->EvaluateAsRelocatable(Value, &Layout)) { + if (Expr->EvaluateAsRelocatable(Value, &Layout, nullptr)) { if (Value.getSymA() && Value.getSymB()) const_cast(&SD.getSymbol())->setAbsolute(); } @@ -668,7 +701,7 @@ IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, // - addr(atom(B)) - offset(B) // and the offsets are not relocatable, so the fixup is fully resolved when // addr(atom(A)) - addr(atom(B)) == 0. - const MCSymbolData *A_Base = 0, *B_Base = 0; + const MCSymbolData *A_Base = nullptr, *B_Base = nullptr; const MCSymbol &SA = DataA.getSymbol().AliasedSymbol(); const MCSection &SecA = SA.getSection(); @@ -737,6 +770,8 @@ IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, void MachObjectWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { unsigned NumSections = Asm.size(); + const MCAssembler::VersionMinInfoType &VersionInfo = + Layout.getAssembler().getVersionMinInfo(); // The section data starts after the header, the segment load command (and // section headers) and the symbol table. @@ -745,6 +780,12 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, sizeof(MachO::segment_command_64) + NumSections * sizeof(MachO::section_64): sizeof(MachO::segment_command) + NumSections * sizeof(MachO::section); + // Add the deployment target version info load command size, if used. + if (VersionInfo.Major != 0) { + ++NumLoadCommands; + LoadCommandsSize += sizeof(MachO::version_min_command); + } + // Add the data-in-code load command size, if used. unsigned NumDataRegions = Asm.getDataRegions().size(); if (NumDataRegions) { @@ -752,6 +793,14 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, LoadCommandsSize += sizeof(MachO::linkedit_data_command); } + // Add the loh load command size, if used. + uint64_t LOHRawSize = Asm.getLOHContainer().getEmitSize(*this, Layout); + uint64_t LOHSize = RoundUpToAlignment(LOHRawSize, is64Bit() ? 8 : 4); + if (LOHSize) { + ++NumLoadCommands; + LoadCommandsSize += sizeof(MachO::linkedit_data_command); + } + // Add the symbol table load command sizes, if used. unsigned NumSymbols = LocalSymbolData.size() + ExternalSymbolData.size() + UndefinedSymbolData.size(); @@ -817,6 +866,20 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, RelocTableEnd += NumRelocs * sizeof(MachO::any_relocation_info); } + // Write out the deployment target information, if it's available. + if (VersionInfo.Major != 0) { + assert(VersionInfo.Update < 256 && "unencodable update target version"); + assert(VersionInfo.Minor < 256 && "unencodable minor target version"); + assert(VersionInfo.Major < 65536 && "unencodable major target version"); + uint32_t EncodedVersion = VersionInfo.Update | (VersionInfo.Minor << 8) | + (VersionInfo.Major << 16); + Write32(VersionInfo.Kind == MCVM_OSXVersionMin ? MachO::LC_VERSION_MIN_MACOSX : + MachO::LC_VERSION_MIN_IPHONEOS); + Write32(sizeof(MachO::version_min_command)); + Write32(EncodedVersion); + Write32(0); // reserved. + } + // Write the data-in-code load command, if used. uint64_t DataInCodeTableEnd = RelocTableEnd + NumDataRegions * 8; if (NumDataRegions) { @@ -826,6 +889,12 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, DataRegionsSize); } + // Write the loh load command, if used. + uint64_t LOHTableEnd = DataInCodeTableEnd + LOHSize; + if (LOHSize) + WriteLinkeditLoadCommand(MachO::LC_LINKER_OPTIMIZATION_HINT, + DataInCodeTableEnd, LOHSize); + // Write the symbol table load command, if used. if (NumSymbols) { unsigned FirstLocalSymbol = 0; @@ -842,10 +911,10 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, // If used, the indirect symbols are written after the section data. if (NumIndirectSymbols) - IndirectSymbolOffset = DataInCodeTableEnd; + IndirectSymbolOffset = LOHTableEnd; // The symbol table is written after the indirect symbol data. - uint64_t SymbolTableOffset = DataInCodeTableEnd + IndirectSymbolSize; + uint64_t SymbolTableOffset = LOHTableEnd + IndirectSymbolSize; // The string table is written after symbol table. uint64_t StringTableOffset = @@ -912,6 +981,17 @@ void MachObjectWriter::WriteObject(MCAssembler &Asm, Write16(Data->Kind); } + // Write out the loh commands, if there is one. + if (LOHSize) { +#ifndef NDEBUG + unsigned Start = OS.tell(); +#endif + Asm.getLOHContainer().Emit(*this, Layout); + // Pad to a multiple of the pointer size. + WriteBytes("", OffsetToAlignment(LOHRawSize, is64Bit() ? 8 : 4)); + assert(OS.tell() - Start == LOHSize); + } + // Write the symbol table data, if used. if (NumSymbols) { // Write the indirect symbol entries.