diff options
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 874 |
1 files changed, 874 insertions, 0 deletions
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp new file mode 100644 index 0000000..190b533 --- /dev/null +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -0,0 +1,874 @@ +//===-- 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<const MCSectionELF*> 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<GlobalVariable>(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<MachineModuleInfoELF>(); + + 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<const MCSectionMachO*> 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<GlobalVariable>(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<Function>(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<const MCSectionCOFF*> 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(); +} + |