//===-- llvm/CodeGen/TargetLoweringObjectFileImpl.cpp - Object File Info --===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file implements classes used to handle lowerings specific to common // object file formats. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" #include "llvm/Function.h" #include "llvm/GlobalVariable.h" #include "llvm/CodeGen/MachineModuleInfoImpls.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCSectionMachO.h" #include "llvm/MC/MCSectionELF.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Target/Mangler.h" #include "llvm/Target/TargetData.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetOptions.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringExtras.h" using namespace llvm; //===----------------------------------------------------------------------===// // ELF //===----------------------------------------------------------------------===// typedef StringMap ELFUniqueMapTy; TargetLoweringObjectFileELF::~TargetLoweringObjectFileELF() { // If we have the section uniquing map, free it. delete (ELFUniqueMapTy*)UniquingMap; } const MCSection *TargetLoweringObjectFileELF:: getELFSection(StringRef Section, unsigned Type, unsigned Flags, SectionKind Kind, bool IsExplicit) const { if (UniquingMap == 0) UniquingMap = new ELFUniqueMapTy(); ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)UniquingMap; // Do the lookup, if we have a hit, return it. const MCSectionELF *&Entry = Map[Section]; if (Entry) return Entry; return Entry = MCSectionELF::Create(Section, Type, Flags, Kind, IsExplicit, getContext()); } void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx, const TargetMachine &TM) { if (UniquingMap != 0) ((ELFUniqueMapTy*)UniquingMap)->clear(); TargetLoweringObjectFile::Initialize(Ctx, TM); BSSSection = getELFSection(".bss", MCSectionELF::SHT_NOBITS, MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC, SectionKind::getBSS()); TextSection = getELFSection(".text", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_EXECINSTR | MCSectionELF::SHF_ALLOC, SectionKind::getText()); DataSection = getELFSection(".data", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_WRITE | MCSectionELF::SHF_ALLOC, SectionKind::getDataRel()); ReadOnlySection = getELFSection(".rodata", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC, SectionKind::getReadOnly()); TLSDataSection = getELFSection(".tdata", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE, SectionKind::getThreadData()); TLSBSSSection = getELFSection(".tbss", MCSectionELF::SHT_NOBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_TLS | MCSectionELF::SHF_WRITE, SectionKind::getThreadBSS()); DataRelSection = getELFSection(".data.rel", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getDataRel()); DataRelLocalSection = getELFSection(".data.rel.local", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getDataRelLocal()); DataRelROSection = getELFSection(".data.rel.ro", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getReadOnlyWithRel()); DataRelROLocalSection = getELFSection(".data.rel.ro.local", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getReadOnlyWithRelLocal()); MergeableConst4Section = getELFSection(".rodata.cst4", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_MERGE, SectionKind::getMergeableConst4()); MergeableConst8Section = getELFSection(".rodata.cst8", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_MERGE, SectionKind::getMergeableConst8()); MergeableConst16Section = getELFSection(".rodata.cst16", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_MERGE, SectionKind::getMergeableConst16()); StaticCtorSection = getELFSection(".ctors", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getDataRel()); StaticDtorSection = getELFSection(".dtors", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getDataRel()); // Exception Handling Sections. // FIXME: We're emitting LSDA info into a readonly section on ELF, even though // it contains relocatable pointers. In PIC mode, this is probably a big // runtime hit for C++ apps. Either the contents of the LSDA need to be // adjusted or this should be a data section. LSDASection = getELFSection(".gcc_except_table", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC, SectionKind::getReadOnly()); EHFrameSection = getELFSection(".eh_frame", MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_WRITE, SectionKind::getDataRel()); // Debug Info Sections. DwarfAbbrevSection = getELFSection(".debug_abbrev", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfInfoSection = getELFSection(".debug_info", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfLineSection = getELFSection(".debug_line", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfFrameSection = getELFSection(".debug_frame", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfPubNamesSection = getELFSection(".debug_pubnames", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfPubTypesSection = getELFSection(".debug_pubtypes", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfStrSection = getELFSection(".debug_str", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfLocSection = getELFSection(".debug_loc", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfARangesSection = getELFSection(".debug_aranges", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfRangesSection = getELFSection(".debug_ranges", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); DwarfMacroInfoSection = getELFSection(".debug_macinfo", MCSectionELF::SHT_PROGBITS, 0, SectionKind::getMetadata()); } static SectionKind getELFKindForNamedSection(StringRef Name, SectionKind K) { if (Name.empty() || Name[0] != '.') return K; // Some lame default implementation based on some magic section names. if (Name == ".bss" || Name.startswith(".bss.") || Name.startswith(".gnu.linkonce.b.") || Name.startswith(".llvm.linkonce.b.") || Name == ".sbss" || Name.startswith(".sbss.") || Name.startswith(".gnu.linkonce.sb.") || Name.startswith(".llvm.linkonce.sb.")) return SectionKind::getBSS(); if (Name == ".tdata" || Name.startswith(".tdata.") || Name.startswith(".gnu.linkonce.td.") || Name.startswith(".llvm.linkonce.td.")) return SectionKind::getThreadData(); if (Name == ".tbss" || Name.startswith(".tbss.") || Name.startswith(".gnu.linkonce.tb.") || Name.startswith(".llvm.linkonce.tb.")) return SectionKind::getThreadBSS(); return K; } static unsigned getELFSectionType(StringRef Name, SectionKind K) { if (Name == ".init_array") return MCSectionELF::SHT_INIT_ARRAY; if (Name == ".fini_array") return MCSectionELF::SHT_FINI_ARRAY; if (Name == ".preinit_array") return MCSectionELF::SHT_PREINIT_ARRAY; if (K.isBSS() || K.isThreadBSS()) return MCSectionELF::SHT_NOBITS; return MCSectionELF::SHT_PROGBITS; } static unsigned getELFSectionFlags(SectionKind K) { unsigned Flags = 0; if (!K.isMetadata()) Flags |= MCSectionELF::SHF_ALLOC; if (K.isText()) Flags |= MCSectionELF::SHF_EXECINSTR; if (K.isWriteable()) Flags |= MCSectionELF::SHF_WRITE; if (K.isThreadLocal()) Flags |= MCSectionELF::SHF_TLS; // K.isMergeableConst() is left out to honour PR4650 if (K.isMergeableCString() || K.isMergeableConst4() || K.isMergeableConst8() || K.isMergeableConst16()) Flags |= MCSectionELF::SHF_MERGE; if (K.isMergeableCString()) Flags |= MCSectionELF::SHF_STRINGS; return Flags; } const MCSection *TargetLoweringObjectFileELF:: getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { StringRef SectionName = GV->getSection(); // Infer section flags from the section name if we can. Kind = getELFKindForNamedSection(SectionName, Kind); return getELFSection(SectionName, getELFSectionType(SectionName, Kind), getELFSectionFlags(Kind), Kind, true); } static const char *getSectionPrefixForUniqueGlobal(SectionKind Kind) { if (Kind.isText()) return ".gnu.linkonce.t."; if (Kind.isReadOnly()) return ".gnu.linkonce.r."; if (Kind.isThreadData()) return ".gnu.linkonce.td."; if (Kind.isThreadBSS()) return ".gnu.linkonce.tb."; if (Kind.isDataNoRel()) return ".gnu.linkonce.d."; if (Kind.isDataRelLocal()) return ".gnu.linkonce.d.rel.local."; if (Kind.isDataRel()) return ".gnu.linkonce.d.rel."; if (Kind.isReadOnlyWithRelLocal()) return ".gnu.linkonce.d.rel.ro.local."; assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); return ".gnu.linkonce.d.rel.ro."; } const MCSection *TargetLoweringObjectFileELF:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { // If this global is linkonce/weak and the target handles this by emitting it // into a 'uniqued' section name, create and return the section now. if (GV->isWeakForLinker() && !Kind.isCommon() && !Kind.isBSS()) { const char *Prefix = getSectionPrefixForUniqueGlobal(Kind); SmallString<128> Name; Name.append(Prefix, Prefix+strlen(Prefix)); Mang->getNameWithPrefix(Name, GV, false); return getELFSection(Name.str(), getELFSectionType(Name.str(), Kind), getELFSectionFlags(Kind), Kind); } if (Kind.isText()) return TextSection; if (Kind.isMergeable1ByteCString() || Kind.isMergeable2ByteCString() || Kind.isMergeable4ByteCString()) { // We also need alignment here. // FIXME: this is getting the alignment of the character, not the // alignment of the global! unsigned Align = TM.getTargetData()->getPreferredAlignment(cast(GV)); const char *SizeSpec = ".rodata.str1."; if (Kind.isMergeable2ByteCString()) SizeSpec = ".rodata.str2."; else if (Kind.isMergeable4ByteCString()) SizeSpec = ".rodata.str4."; else assert(Kind.isMergeable1ByteCString() && "unknown string width"); std::string Name = SizeSpec + utostr(Align); return getELFSection(Name, MCSectionELF::SHT_PROGBITS, MCSectionELF::SHF_ALLOC | MCSectionELF::SHF_MERGE | MCSectionELF::SHF_STRINGS, Kind); } if (Kind.isMergeableConst()) { if (Kind.isMergeableConst4() && MergeableConst4Section) return MergeableConst4Section; if (Kind.isMergeableConst8() && MergeableConst8Section) return MergeableConst8Section; if (Kind.isMergeableConst16() && MergeableConst16Section) return MergeableConst16Section; return ReadOnlySection; // .const } if (Kind.isReadOnly()) return ReadOnlySection; if (Kind.isThreadData()) return TLSDataSection; if (Kind.isThreadBSS()) return TLSBSSSection; // Note: we claim that common symbols are put in BSSSection, but they are // really emitted with the magic .comm directive, which creates a symbol table // entry but not a section. if (Kind.isBSS() || Kind.isCommon()) return BSSSection; if (Kind.isDataNoRel()) return DataSection; if (Kind.isDataRelLocal()) return DataRelLocalSection; if (Kind.isDataRel()) return DataRelSection; if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection; assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); return DataRelROSection; } /// getSectionForConstant - Given a mergeable constant with the /// specified size and relocation information, return a section that it /// should be placed in. const MCSection *TargetLoweringObjectFileELF:: getSectionForConstant(SectionKind Kind) const { if (Kind.isMergeableConst4() && MergeableConst4Section) return MergeableConst4Section; if (Kind.isMergeableConst8() && MergeableConst8Section) return MergeableConst8Section; if (Kind.isMergeableConst16() && MergeableConst16Section) return MergeableConst16Section; if (Kind.isReadOnly()) return ReadOnlySection; if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection; assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); return DataRelROSection; } const MCExpr *TargetLoweringObjectFileELF:: getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang, MachineModuleInfo *MMI, unsigned Encoding) const { if (Encoding & dwarf::DW_EH_PE_indirect) { MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo(); SmallString<128> Name; Mang->getNameWithPrefix(Name, GV, true); Name += ".DW.stub"; // Add information about the stub reference to ELFMMI so that the stub // gets emitted by the asmprinter. MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str()); MCSymbol *&StubSym = ELFMMI.getGVStubEntry(Sym); if (StubSym == 0) { Name.clear(); Mang->getNameWithPrefix(Name, GV, false); StubSym = getContext().GetOrCreateSymbol(Name.str()); } return TargetLoweringObjectFile:: getSymbolForDwarfReference(Sym, MMI, Encoding & ~dwarf::DW_EH_PE_indirect); } return TargetLoweringObjectFile:: getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding); } //===----------------------------------------------------------------------===// // MachO //===----------------------------------------------------------------------===// typedef StringMap MachOUniqueMapTy; TargetLoweringObjectFileMachO::~TargetLoweringObjectFileMachO() { // If we have the MachO uniquing map, free it. delete (MachOUniqueMapTy*)UniquingMap; } const MCSectionMachO *TargetLoweringObjectFileMachO:: getMachOSection(StringRef Segment, StringRef Section, unsigned TypeAndAttributes, unsigned Reserved2, SectionKind Kind) const { // We unique sections by their segment/section pair. The returned section // may not have the same flags as the requested section, if so this should be // diagnosed by the client as an error. // Create the map if it doesn't already exist. if (UniquingMap == 0) UniquingMap = new MachOUniqueMapTy(); MachOUniqueMapTy &Map = *(MachOUniqueMapTy*)UniquingMap; // Form the name to look up. SmallString<64> Name; Name += Segment; Name.push_back(','); Name += Section; // Do the lookup, if we have a hit, return it. const MCSectionMachO *&Entry = Map[Name.str()]; if (Entry) return Entry; // Otherwise, return a new section. return Entry = MCSectionMachO::Create(Segment, Section, TypeAndAttributes, Reserved2, Kind, getContext()); } void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx, const TargetMachine &TM) { if (UniquingMap != 0) ((MachOUniqueMapTy*)UniquingMap)->clear(); TargetLoweringObjectFile::Initialize(Ctx, TM); TextSection // .text = getMachOSection("__TEXT", "__text", MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, SectionKind::getText()); DataSection // .data = getMachOSection("__DATA", "__data", 0, SectionKind::getDataRel()); CStringSection // .cstring = getMachOSection("__TEXT", "__cstring", MCSectionMachO::S_CSTRING_LITERALS, SectionKind::getMergeable1ByteCString()); UStringSection = getMachOSection("__TEXT","__ustring", 0, SectionKind::getMergeable2ByteCString()); FourByteConstantSection // .literal4 = getMachOSection("__TEXT", "__literal4", MCSectionMachO::S_4BYTE_LITERALS, SectionKind::getMergeableConst4()); EightByteConstantSection // .literal8 = getMachOSection("__TEXT", "__literal8", MCSectionMachO::S_8BYTE_LITERALS, SectionKind::getMergeableConst8()); // ld_classic doesn't support .literal16 in 32-bit mode, and ld64 falls back // to using it in -static mode. SixteenByteConstantSection = 0; if (TM.getRelocationModel() != Reloc::Static && TM.getTargetData()->getPointerSize() == 32) SixteenByteConstantSection = // .literal16 getMachOSection("__TEXT", "__literal16",MCSectionMachO::S_16BYTE_LITERALS, SectionKind::getMergeableConst16()); ReadOnlySection // .const = getMachOSection("__TEXT", "__const", 0, SectionKind::getReadOnly()); TextCoalSection = getMachOSection("__TEXT", "__textcoal_nt", MCSectionMachO::S_COALESCED | MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, SectionKind::getText()); ConstTextCoalSection = getMachOSection("__TEXT", "__const_coal", MCSectionMachO::S_COALESCED, SectionKind::getText()); ConstDataCoalSection = getMachOSection("__DATA","__const_coal", MCSectionMachO::S_COALESCED, SectionKind::getText()); ConstDataSection // .const_data = getMachOSection("__DATA", "__const", 0, SectionKind::getReadOnlyWithRel()); DataCoalSection = getMachOSection("__DATA","__datacoal_nt", MCSectionMachO::S_COALESCED, SectionKind::getDataRel()); DataCommonSection = getMachOSection("__DATA","__common", MCSectionMachO::S_ZEROFILL, SectionKind::getBSS()); DataBSSSection = getMachOSection("__DATA","__bss", MCSectionMachO::S_ZEROFILL, SectionKind::getBSS()); LazySymbolPointerSection = getMachOSection("__DATA", "__la_symbol_ptr", MCSectionMachO::S_LAZY_SYMBOL_POINTERS, SectionKind::getMetadata()); NonLazySymbolPointerSection = getMachOSection("__DATA", "__nl_symbol_ptr", MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS, SectionKind::getMetadata()); if (TM.getRelocationModel() == Reloc::Static) { StaticCtorSection = getMachOSection("__TEXT", "__constructor", 0,SectionKind::getDataRel()); StaticDtorSection = getMachOSection("__TEXT", "__destructor", 0, SectionKind::getDataRel()); } else { StaticCtorSection = getMachOSection("__DATA", "__mod_init_func", MCSectionMachO::S_MOD_INIT_FUNC_POINTERS, SectionKind::getDataRel()); StaticDtorSection = getMachOSection("__DATA", "__mod_term_func", MCSectionMachO::S_MOD_TERM_FUNC_POINTERS, SectionKind::getDataRel()); } // Exception Handling. LSDASection = getMachOSection("__DATA", "__gcc_except_tab", 0, SectionKind::getDataRel()); EHFrameSection = getMachOSection("__TEXT", "__eh_frame", MCSectionMachO::S_COALESCED | MCSectionMachO::S_ATTR_NO_TOC | MCSectionMachO::S_ATTR_STRIP_STATIC_SYMS | MCSectionMachO::S_ATTR_LIVE_SUPPORT, SectionKind::getReadOnly()); // Debug Information. DwarfAbbrevSection = getMachOSection("__DWARF", "__debug_abbrev", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfInfoSection = getMachOSection("__DWARF", "__debug_info", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfLineSection = getMachOSection("__DWARF", "__debug_line", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfFrameSection = getMachOSection("__DWARF", "__debug_frame", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfPubNamesSection = getMachOSection("__DWARF", "__debug_pubnames", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfPubTypesSection = getMachOSection("__DWARF", "__debug_pubtypes", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfStrSection = getMachOSection("__DWARF", "__debug_str", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfLocSection = getMachOSection("__DWARF", "__debug_loc", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfARangesSection = getMachOSection("__DWARF", "__debug_aranges", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfRangesSection = getMachOSection("__DWARF", "__debug_ranges", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfMacroInfoSection = getMachOSection("__DWARF", "__debug_macinfo", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); DwarfDebugInlineSection = getMachOSection("__DWARF", "__debug_inlined", MCSectionMachO::S_ATTR_DEBUG, SectionKind::getMetadata()); } const MCSection *TargetLoweringObjectFileMachO:: getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { // Parse the section specifier and create it if valid. StringRef Segment, Section; unsigned TAA, StubSize; std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section, TAA, StubSize); if (!ErrorCode.empty()) { // If invalid, report the error with llvm_report_error. llvm_report_error("Global variable '" + GV->getNameStr() + "' has an invalid section specifier '" + GV->getSection()+ "': " + ErrorCode + "."); // Fall back to dropping it into the data section. return DataSection; } // Get the section. const MCSectionMachO *S = getMachOSection(Segment, Section, TAA, StubSize, Kind); // Okay, now that we got the section, verify that the TAA & StubSize agree. // If the user declared multiple globals with different section flags, we need // to reject it here. if (S->getTypeAndAttributes() != TAA || S->getStubSize() != StubSize) { // If invalid, report the error with llvm_report_error. llvm_report_error("Global variable '" + GV->getNameStr() + "' section type or attributes does not match previous" " section specifier"); } return S; } const MCSection *TargetLoweringObjectFileMachO:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { assert(!Kind.isThreadLocal() && "Darwin doesn't support TLS"); if (Kind.isText()) return GV->isWeakForLinker() ? TextCoalSection : TextSection; // If this is weak/linkonce, put this in a coalescable section, either in text // or data depending on if it is writable. if (GV->isWeakForLinker()) { if (Kind.isReadOnly()) return ConstTextCoalSection; return DataCoalSection; } // FIXME: Alignment check should be handled by section classifier. if (Kind.isMergeable1ByteCString() || Kind.isMergeable2ByteCString()) { if (TM.getTargetData()->getPreferredAlignment( cast(GV)) < 32) { if (Kind.isMergeable1ByteCString()) return CStringSection; assert(Kind.isMergeable2ByteCString()); return UStringSection; } } if (Kind.isMergeableConst()) { if (Kind.isMergeableConst4()) return FourByteConstantSection; if (Kind.isMergeableConst8()) return EightByteConstantSection; if (Kind.isMergeableConst16() && SixteenByteConstantSection) return SixteenByteConstantSection; } // Otherwise, if it is readonly, but not something we can specially optimize, // just drop it in .const. if (Kind.isReadOnly()) return ReadOnlySection; // If this is marked const, put it into a const section. But if the dynamic // linker needs to write to it, put it in the data segment. if (Kind.isReadOnlyWithRel()) return ConstDataSection; // Put zero initialized globals with strong external linkage in the // DATA, __common section with the .zerofill directive. if (Kind.isBSSExtern()) return DataCommonSection; // Put zero initialized globals with local linkage in __DATA,__bss directive // with the .zerofill directive (aka .lcomm). if (Kind.isBSSLocal()) return DataBSSSection; // Otherwise, just drop the variable in the normal data section. return DataSection; } const MCSection * TargetLoweringObjectFileMachO::getSectionForConstant(SectionKind Kind) const { // If this constant requires a relocation, we have to put it in the data // segment, not in the text segment. if (Kind.isDataRel() || Kind.isReadOnlyWithRel()) return ConstDataSection; if (Kind.isMergeableConst4()) return FourByteConstantSection; if (Kind.isMergeableConst8()) return EightByteConstantSection; if (Kind.isMergeableConst16() && SixteenByteConstantSection) return SixteenByteConstantSection; return ReadOnlySection; // .const } /// shouldEmitUsedDirectiveFor - This hook allows targets to selectively decide /// not to emit the UsedDirective for some symbols in llvm.used. // FIXME: REMOVE this (rdar://7071300) bool TargetLoweringObjectFileMachO:: shouldEmitUsedDirectiveFor(const GlobalValue *GV, Mangler *Mang) const { /// On Darwin, internally linked data beginning with "L" or "l" does not have /// the directive emitted (this occurs in ObjC metadata). if (!GV) return false; // Check whether the mangled name has the "Private" or "LinkerPrivate" prefix. if (GV->hasLocalLinkage() && !isa(GV)) { // FIXME: ObjC metadata is currently emitted as internal symbols that have // \1L and \0l prefixes on them. Fix them to be Private/LinkerPrivate and // this horrible hack can go away. SmallString<64> Name; Mang->getNameWithPrefix(Name, GV, false); if (Name[0] == 'L' || Name[0] == 'l') return false; } return true; } const MCExpr *TargetLoweringObjectFileMachO:: getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang, MachineModuleInfo *MMI, unsigned Encoding) const { // The mach-o version of this method defaults to returning a stub reference. if (Encoding & dwarf::DW_EH_PE_indirect) { SmallString<128> Name; Mang->getNameWithPrefix(Name, GV, true); Name += "$non_lazy_ptr"; MCSymbol *Sym = getContext().GetOrCreateSymbol(Name.str()); return TargetLoweringObjectFile:: getSymbolForDwarfReference(Sym, MMI, Encoding & ~dwarf::DW_EH_PE_indirect); } return TargetLoweringObjectFile:: getSymbolForDwarfGlobalReference(GV, Mang, MMI, Encoding); } //===----------------------------------------------------------------------===// // COFF //===----------------------------------------------------------------------===// typedef StringMap COFFUniqueMapTy; TargetLoweringObjectFileCOFF::~TargetLoweringObjectFileCOFF() { delete (COFFUniqueMapTy*)UniquingMap; } const MCSection *TargetLoweringObjectFileCOFF:: getCOFFSection(StringRef Name, bool isDirective, SectionKind Kind) const { // Create the map if it doesn't already exist. if (UniquingMap == 0) UniquingMap = new MachOUniqueMapTy(); COFFUniqueMapTy &Map = *(COFFUniqueMapTy*)UniquingMap; // Do the lookup, if we have a hit, return it. const MCSectionCOFF *&Entry = Map[Name]; if (Entry) return Entry; return Entry = MCSectionCOFF::Create(Name, isDirective, Kind, getContext()); } void TargetLoweringObjectFileCOFF::Initialize(MCContext &Ctx, const TargetMachine &TM) { if (UniquingMap != 0) ((COFFUniqueMapTy*)UniquingMap)->clear(); TargetLoweringObjectFile::Initialize(Ctx, TM); TextSection = getCOFFSection("\t.text", true, SectionKind::getText()); DataSection = getCOFFSection("\t.data", true, SectionKind::getDataRel()); StaticCtorSection = getCOFFSection(".ctors", false, SectionKind::getDataRel()); StaticDtorSection = getCOFFSection(".dtors", false, SectionKind::getDataRel()); // FIXME: We're emitting LSDA info into a readonly section on COFF, even // though it contains relocatable pointers. In PIC mode, this is probably a // big runtime hit for C++ apps. Either the contents of the LSDA need to be // adjusted or this should be a data section. LSDASection = getCOFFSection(".gcc_except_table", false, SectionKind::getReadOnly()); EHFrameSection = getCOFFSection(".eh_frame", false, SectionKind::getDataRel()); // Debug info. // FIXME: Don't use 'directive' mode here. DwarfAbbrevSection = getCOFFSection("\t.section\t.debug_abbrev,\"dr\"", true, SectionKind::getMetadata()); DwarfInfoSection = getCOFFSection("\t.section\t.debug_info,\"dr\"", true, SectionKind::getMetadata()); DwarfLineSection = getCOFFSection("\t.section\t.debug_line,\"dr\"", true, SectionKind::getMetadata()); DwarfFrameSection = getCOFFSection("\t.section\t.debug_frame,\"dr\"", true, SectionKind::getMetadata()); DwarfPubNamesSection = getCOFFSection("\t.section\t.debug_pubnames,\"dr\"", true, SectionKind::getMetadata()); DwarfPubTypesSection = getCOFFSection("\t.section\t.debug_pubtypes,\"dr\"", true, SectionKind::getMetadata()); DwarfStrSection = getCOFFSection("\t.section\t.debug_str,\"dr\"", true, SectionKind::getMetadata()); DwarfLocSection = getCOFFSection("\t.section\t.debug_loc,\"dr\"", true, SectionKind::getMetadata()); DwarfARangesSection = getCOFFSection("\t.section\t.debug_aranges,\"dr\"", true, SectionKind::getMetadata()); DwarfRangesSection = getCOFFSection("\t.section\t.debug_ranges,\"dr\"", true, SectionKind::getMetadata()); DwarfMacroInfoSection = getCOFFSection("\t.section\t.debug_macinfo,\"dr\"", true, SectionKind::getMetadata()); } const MCSection *TargetLoweringObjectFileCOFF:: getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { return getCOFFSection(GV->getSection(), false, Kind); } static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) { if (Kind.isText()) return ".text$linkonce"; if (Kind.isWriteable()) return ".data$linkonce"; return ".rdata$linkonce"; } const MCSection *TargetLoweringObjectFileCOFF:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang, const TargetMachine &TM) const { assert(!Kind.isThreadLocal() && "Doesn't support TLS"); // If this global is linkonce/weak and the target handles this by emitting it // into a 'uniqued' section name, create and return the section now. if (GV->isWeakForLinker()) { const char *Prefix = getCOFFSectionPrefixForUniqueGlobal(Kind); SmallString<128> Name(Prefix, Prefix+strlen(Prefix)); Mang->getNameWithPrefix(Name, GV, false); return getCOFFSection(Name.str(), false, Kind); } if (Kind.isText()) return getTextSection(); return getDataSection(); }