| //===-- 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/MCSectionCOFF.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/ELF.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/Triple.h" |
| using namespace llvm; |
| using namespace dwarf; |
| |
| //===----------------------------------------------------------------------===// |
| // ELF |
| //===----------------------------------------------------------------------===// |
| |
| void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx, |
| const TargetMachine &TM) { |
| TargetLoweringObjectFile::Initialize(Ctx, TM); |
| |
| BSSSection = |
| getContext().getELFSection(".bss", ELF::SHT_NOBITS, |
| ELF::SHF_WRITE |ELF::SHF_ALLOC, |
| SectionKind::getBSS()); |
| |
| TextSection = |
| getContext().getELFSection(".text", ELF::SHT_PROGBITS, |
| ELF::SHF_EXECINSTR | |
| ELF::SHF_ALLOC, |
| SectionKind::getText()); |
| |
| DataSection = |
| getContext().getELFSection(".data", ELF::SHT_PROGBITS, |
| ELF::SHF_WRITE |ELF::SHF_ALLOC, |
| SectionKind::getDataRel()); |
| |
| ReadOnlySection = |
| getContext().getELFSection(".rodata", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC, |
| SectionKind::getReadOnly()); |
| |
| TLSDataSection = |
| getContext().getELFSection(".tdata", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | ELF::SHF_TLS | |
| ELF::SHF_WRITE, |
| SectionKind::getThreadData()); |
| |
| TLSBSSSection = |
| getContext().getELFSection(".tbss", ELF::SHT_NOBITS, |
| ELF::SHF_ALLOC | ELF::SHF_TLS | |
| ELF::SHF_WRITE, |
| SectionKind::getThreadBSS()); |
| |
| DataRelSection = |
| getContext().getELFSection(".data.rel", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_WRITE, |
| SectionKind::getDataRel()); |
| |
| DataRelLocalSection = |
| getContext().getELFSection(".data.rel.local", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_WRITE, |
| SectionKind::getDataRelLocal()); |
| |
| DataRelROSection = |
| getContext().getELFSection(".data.rel.ro", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_WRITE, |
| SectionKind::getReadOnlyWithRel()); |
| |
| DataRelROLocalSection = |
| getContext().getELFSection(".data.rel.ro.local", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_WRITE, |
| SectionKind::getReadOnlyWithRelLocal()); |
| |
| MergeableConst4Section = |
| getContext().getELFSection(".rodata.cst4", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_MERGE, |
| SectionKind::getMergeableConst4()); |
| |
| MergeableConst8Section = |
| getContext().getELFSection(".rodata.cst8", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_MERGE, |
| SectionKind::getMergeableConst8()); |
| |
| MergeableConst16Section = |
| getContext().getELFSection(".rodata.cst16", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_MERGE, |
| SectionKind::getMergeableConst16()); |
| |
| StaticCtorSection = |
| getContext().getELFSection(".ctors", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::SHF_WRITE, |
| SectionKind::getDataRel()); |
| |
| StaticDtorSection = |
| getContext().getELFSection(".dtors", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC |ELF::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 = |
| getContext().getELFSection(".gcc_except_table", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC, |
| SectionKind::getReadOnly()); |
| // Debug Info Sections. |
| DwarfAbbrevSection = |
| getContext().getELFSection(".debug_abbrev", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfInfoSection = |
| getContext().getELFSection(".debug_info", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfLineSection = |
| getContext().getELFSection(".debug_line", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfFrameSection = |
| getContext().getELFSection(".debug_frame", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfPubNamesSection = |
| getContext().getELFSection(".debug_pubnames", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfPubTypesSection = |
| getContext().getELFSection(".debug_pubtypes", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfStrSection = |
| getContext().getELFSection(".debug_str", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfLocSection = |
| getContext().getELFSection(".debug_loc", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfARangesSection = |
| getContext().getELFSection(".debug_aranges", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfRangesSection = |
| getContext().getELFSection(".debug_ranges", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| DwarfMacroInfoSection = |
| getContext().getELFSection(".debug_macinfo", ELF::SHT_PROGBITS, 0, |
| SectionKind::getMetadata()); |
| } |
| |
| const MCSection *TargetLoweringObjectFileELF::getEHFrameSection() const { |
| return getContext().getELFSection(".eh_frame", ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC, |
| SectionKind::getDataRel()); |
| } |
| |
| static SectionKind |
| getELFKindForNamedSection(StringRef Name, SectionKind K) { |
| // FIXME: Why is this here? Codegen is should not be in the business |
| // of figuring section flags. If the user wrote section(".eh_frame"), |
| // we should just pass that to MC which will defer to the assembly |
| // or use its default if producing an object file. |
| 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(); |
| |
| if (Name == ".eh_frame") |
| return SectionKind::getDataRel(); |
| |
| return K; |
| } |
| |
| |
| static unsigned getELFSectionType(StringRef Name, SectionKind K) { |
| |
| if (Name == ".init_array") |
| return ELF::SHT_INIT_ARRAY; |
| |
| if (Name == ".fini_array") |
| return ELF::SHT_FINI_ARRAY; |
| |
| if (Name == ".preinit_array") |
| return ELF::SHT_PREINIT_ARRAY; |
| |
| if (K.isBSS() || K.isThreadBSS()) |
| return ELF::SHT_NOBITS; |
| |
| return ELF::SHT_PROGBITS; |
| } |
| |
| |
| static unsigned |
| getELFSectionFlags(SectionKind K) { |
| unsigned Flags = 0; |
| |
| if (!K.isMetadata()) |
| Flags |= ELF::SHF_ALLOC; |
| |
| if (K.isText()) |
| Flags |= ELF::SHF_EXECINSTR; |
| |
| if (K.isWriteable()) |
| Flags |= ELF::SHF_WRITE; |
| |
| if (K.isThreadLocal()) |
| Flags |= ELF::SHF_TLS; |
| |
| // K.isMergeableConst() is left out to honour PR4650 |
| if (K.isMergeableCString() || K.isMergeableConst4() || |
| K.isMergeableConst8() || K.isMergeableConst16()) |
| Flags |= ELF::SHF_MERGE; |
| |
| if (K.isMergeableCString()) |
| Flags |= ELF::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 getContext().getELFSection(SectionName, |
| getELFSectionType(SectionName, Kind), |
| getELFSectionFlags(Kind), Kind); |
| } |
| |
| /// getSectionPrefixForGlobal - Return the section prefix name used by options |
| /// FunctionsSections and DataSections. |
| static const char *getSectionPrefixForGlobal(SectionKind Kind) { |
| if (Kind.isText()) return ".text."; |
| if (Kind.isReadOnly()) return ".rodata."; |
| |
| if (Kind.isThreadData()) return ".tdata."; |
| if (Kind.isThreadBSS()) return ".tbss."; |
| |
| if (Kind.isDataNoRel()) return ".data."; |
| if (Kind.isDataRelLocal()) return ".data.rel.local."; |
| if (Kind.isDataRel()) return ".data.rel."; |
| if (Kind.isReadOnlyWithRelLocal()) return ".data.rel.ro.local."; |
| |
| assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); |
| return ".data.rel.ro."; |
| } |
| |
| |
| const MCSection *TargetLoweringObjectFileELF:: |
| SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, |
| Mangler *Mang, const TargetMachine &TM) const { |
| // If we have -ffunction-section or -fdata-section then we should emit the |
| // global value to a uniqued section specifically for it. |
| bool EmitUniquedSection; |
| if (Kind.isText()) |
| EmitUniquedSection = TM.getFunctionSections(); |
| else |
| EmitUniquedSection = TM.getDataSections(); |
| |
| // 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() || EmitUniquedSection) && |
| !Kind.isCommon() && !Kind.isBSS()) { |
| const char *Prefix; |
| Prefix = getSectionPrefixForGlobal(Kind); |
| |
| SmallString<128> Name(Prefix, Prefix+strlen(Prefix)); |
| MCSymbol *Sym = Mang->getSymbol(GV); |
| Name.append(Sym->getName().begin(), Sym->getName().end()); |
| StringRef Group = ""; |
| unsigned Flags = getELFSectionFlags(Kind); |
| if (GV->isWeakForLinker()) { |
| Group = Sym->getName(); |
| Flags |= ELF::SHF_GROUP; |
| } |
| |
| return getContext().getELFSection(Name.str(), |
| getELFSectionType(Name.str(), Kind), |
| Flags, Kind, 0, Group); |
| } |
| |
| 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 getContext().getELFSection(Name, ELF::SHT_PROGBITS, |
| ELF::SHF_ALLOC | |
| ELF::SHF_MERGE | |
| ELF::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:: |
| getExprForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang, |
| MachineModuleInfo *MMI, |
| unsigned Encoding, MCStreamer &Streamer) 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 *SSym = getContext().GetOrCreateSymbol(Name.str()); |
| MachineModuleInfoImpl::StubValueTy &StubSym = ELFMMI.getGVStubEntry(SSym); |
| if (StubSym.getPointer() == 0) { |
| MCSymbol *Sym = Mang->getSymbol(GV); |
| StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage()); |
| } |
| |
| return TargetLoweringObjectFile:: |
| getExprForDwarfReference(SSym, Mang, MMI, |
| Encoding & ~dwarf::DW_EH_PE_indirect, Streamer); |
| } |
| |
| return TargetLoweringObjectFile:: |
| getExprForDwarfGlobalReference(GV, Mang, MMI, Encoding, Streamer); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // MachO |
| //===----------------------------------------------------------------------===// |
| |
| void TargetLoweringObjectFileMachO::Initialize(MCContext &Ctx, |
| const TargetMachine &TM) { |
| // _foo.eh symbols are currently always exported so that the linker knows |
| // about them. This is not necessary on 10.6 and later, but it |
| // doesn't hurt anything. |
| // FIXME: I need to get this from Triple. |
| IsFunctionEHSymbolGlobal = true; |
| IsFunctionEHFrameSymbolPrivate = false; |
| SupportsWeakOmittedEHFrame = false; |
| |
| Triple T(((LLVMTargetMachine&)TM).getTargetTriple()); |
| if (T.getOS() == Triple::Darwin) { |
| switch (T.getDarwinMajorNumber()) { |
| case 7: // 10.3 Panther. |
| case 8: // 10.4 Tiger. |
| CommDirectiveSupportsAlignment = false; |
| break; |
| case 9: // 10.5 Leopard. |
| case 10: // 10.6 SnowLeopard. |
| break; |
| } |
| } |
| |
| TargetLoweringObjectFile::Initialize(Ctx, TM); |
| |
| TextSection // .text |
| = getContext().getMachOSection("__TEXT", "__text", |
| MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, |
| SectionKind::getText()); |
| DataSection // .data |
| = getContext().getMachOSection("__DATA", "__data", 0, |
| SectionKind::getDataRel()); |
| |
| TLSDataSection // .tdata |
| = getContext().getMachOSection("__DATA", "__thread_data", |
| MCSectionMachO::S_THREAD_LOCAL_REGULAR, |
| SectionKind::getDataRel()); |
| TLSBSSSection // .tbss |
| = getContext().getMachOSection("__DATA", "__thread_bss", |
| MCSectionMachO::S_THREAD_LOCAL_ZEROFILL, |
| SectionKind::getThreadBSS()); |
| |
| // TODO: Verify datarel below. |
| TLSTLVSection // .tlv |
| = getContext().getMachOSection("__DATA", "__thread_vars", |
| MCSectionMachO::S_THREAD_LOCAL_VARIABLES, |
| SectionKind::getDataRel()); |
| |
| TLSThreadInitSection |
| = getContext().getMachOSection("__DATA", "__thread_init", |
| MCSectionMachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS, |
| SectionKind::getDataRel()); |
| |
| CStringSection // .cstring |
| = getContext().getMachOSection("__TEXT", "__cstring", |
| MCSectionMachO::S_CSTRING_LITERALS, |
| SectionKind::getMergeable1ByteCString()); |
| UStringSection |
| = getContext().getMachOSection("__TEXT","__ustring", 0, |
| SectionKind::getMergeable2ByteCString()); |
| FourByteConstantSection // .literal4 |
| = getContext().getMachOSection("__TEXT", "__literal4", |
| MCSectionMachO::S_4BYTE_LITERALS, |
| SectionKind::getMergeableConst4()); |
| EightByteConstantSection // .literal8 |
| = getContext().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 |
| getContext().getMachOSection("__TEXT", "__literal16", |
| MCSectionMachO::S_16BYTE_LITERALS, |
| SectionKind::getMergeableConst16()); |
| |
| ReadOnlySection // .const |
| = getContext().getMachOSection("__TEXT", "__const", 0, |
| SectionKind::getReadOnly()); |
| |
| TextCoalSection |
| = getContext().getMachOSection("__TEXT", "__textcoal_nt", |
| MCSectionMachO::S_COALESCED | |
| MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, |
| SectionKind::getText()); |
| ConstTextCoalSection |
| = getContext().getMachOSection("__TEXT", "__const_coal", |
| MCSectionMachO::S_COALESCED, |
| SectionKind::getReadOnly()); |
| ConstDataSection // .const_data |
| = getContext().getMachOSection("__DATA", "__const", 0, |
| SectionKind::getReadOnlyWithRel()); |
| DataCoalSection |
| = getContext().getMachOSection("__DATA","__datacoal_nt", |
| MCSectionMachO::S_COALESCED, |
| SectionKind::getDataRel()); |
| DataCommonSection |
| = getContext().getMachOSection("__DATA","__common", |
| MCSectionMachO::S_ZEROFILL, |
| SectionKind::getBSS()); |
| DataBSSSection |
| = getContext().getMachOSection("__DATA","__bss", MCSectionMachO::S_ZEROFILL, |
| SectionKind::getBSS()); |
| |
| |
| LazySymbolPointerSection |
| = getContext().getMachOSection("__DATA", "__la_symbol_ptr", |
| MCSectionMachO::S_LAZY_SYMBOL_POINTERS, |
| SectionKind::getMetadata()); |
| NonLazySymbolPointerSection |
| = getContext().getMachOSection("__DATA", "__nl_symbol_ptr", |
| MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS, |
| SectionKind::getMetadata()); |
| |
| if (TM.getRelocationModel() == Reloc::Static) { |
| StaticCtorSection |
| = getContext().getMachOSection("__TEXT", "__constructor", 0, |
| SectionKind::getDataRel()); |
| StaticDtorSection |
| = getContext().getMachOSection("__TEXT", "__destructor", 0, |
| SectionKind::getDataRel()); |
| } else { |
| StaticCtorSection |
| = getContext().getMachOSection("__DATA", "__mod_init_func", |
| MCSectionMachO::S_MOD_INIT_FUNC_POINTERS, |
| SectionKind::getDataRel()); |
| StaticDtorSection |
| = getContext().getMachOSection("__DATA", "__mod_term_func", |
| MCSectionMachO::S_MOD_TERM_FUNC_POINTERS, |
| SectionKind::getDataRel()); |
| } |
| |
| // Exception Handling. |
| LSDASection = getContext().getMachOSection("__TEXT", "__gcc_except_tab", 0, |
| SectionKind::getReadOnlyWithRel()); |
| // Debug Information. |
| DwarfAbbrevSection = |
| getContext().getMachOSection("__DWARF", "__debug_abbrev", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfInfoSection = |
| getContext().getMachOSection("__DWARF", "__debug_info", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfLineSection = |
| getContext().getMachOSection("__DWARF", "__debug_line", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfFrameSection = |
| getContext().getMachOSection("__DWARF", "__debug_frame", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfPubNamesSection = |
| getContext().getMachOSection("__DWARF", "__debug_pubnames", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfPubTypesSection = |
| getContext().getMachOSection("__DWARF", "__debug_pubtypes", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfStrSection = |
| getContext().getMachOSection("__DWARF", "__debug_str", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfLocSection = |
| getContext().getMachOSection("__DWARF", "__debug_loc", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfARangesSection = |
| getContext().getMachOSection("__DWARF", "__debug_aranges", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfRangesSection = |
| getContext().getMachOSection("__DWARF", "__debug_ranges", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfMacroInfoSection = |
| getContext().getMachOSection("__DWARF", "__debug_macinfo", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| DwarfDebugInlineSection = |
| getContext().getMachOSection("__DWARF", "__debug_inlined", |
| MCSectionMachO::S_ATTR_DEBUG, |
| SectionKind::getMetadata()); |
| |
| TLSExtraDataSection = TLSTLVSection; |
| } |
| |
| const MCSection *TargetLoweringObjectFileMachO::getEHFrameSection() const { |
| return getContext().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()); |
| } |
| |
| 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 = (unsigned)MCSectionMachO::SECTION_ATTRIBUTES, StubSize = 0; |
| std::string ErrorCode = |
| MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section, |
| TAA, StubSize); |
| if (!ErrorCode.empty()) { |
| // If invalid, report the error with report_fatal_error. |
| report_fatal_error("Global variable '" + GV->getNameStr() + |
| "' has an invalid section specifier '" + GV->getSection()+ |
| "': " + ErrorCode + "."); |
| // Fall back to dropping it into the data section. |
| return DataSection; |
| } |
| |
| bool TAAWasSet = (TAA != MCSectionMachO::SECTION_ATTRIBUTES); |
| if (!TAAWasSet) |
| TAA = 0; // Sensible default if this is a new section. |
| |
| // Get the section. |
| const MCSectionMachO *S = |
| getContext().getMachOSection(Segment, Section, TAA, StubSize, Kind); |
| |
| // If TAA wasn't set by ParseSectionSpecifier() above, |
| // use the value returned by getMachOSection() as a default. |
| if (!TAAWasSet) |
| TAA = S->getTypeAndAttributes(); |
| |
| // 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 report_fatal_error. |
| report_fatal_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 { |
| |
| // Handle thread local data. |
| if (Kind.isThreadBSS()) return TLSBSSSection; |
| if (Kind.isThreadData()) return TLSDataSection; |
| |
| 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() && |
| TM.getTargetData()->getPreferredAlignment(cast<GlobalVariable>(GV)) < 32) |
| return CStringSection; |
| |
| // Do not put 16-bit arrays in the UString section if they have an |
| // externally visible label, this runs into issues with certain linker |
| // versions. |
| if (Kind.isMergeable2ByteCString() && !GV->hasExternalLinkage() && |
| TM.getTargetData()->getPreferredAlignment(cast<GlobalVariable>(GV)) < 32) |
| 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. |
| MCSymbol *Sym = Mang->getSymbol(GV); |
| if (Sym->getName()[0] == 'L' || Sym->getName()[0] == 'l') |
| return false; |
| } |
| |
| return true; |
| } |
| |
| const MCExpr *TargetLoweringObjectFileMachO:: |
| getExprForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang, |
| MachineModuleInfo *MMI, unsigned Encoding, |
| MCStreamer &Streamer) const { |
| // The mach-o version of this method defaults to returning a stub reference. |
| |
| if (Encoding & DW_EH_PE_indirect) { |
| MachineModuleInfoMachO &MachOMMI = |
| MMI->getObjFileInfo<MachineModuleInfoMachO>(); |
| |
| SmallString<128> Name; |
| Mang->getNameWithPrefix(Name, GV, true); |
| Name += "$non_lazy_ptr"; |
| |
| // Add information about the stub reference to MachOMMI so that the stub |
| // gets emitted by the asmprinter. |
| MCSymbol *SSym = getContext().GetOrCreateSymbol(Name.str()); |
| MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym); |
| if (StubSym.getPointer() == 0) { |
| MCSymbol *Sym = Mang->getSymbol(GV); |
| StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage()); |
| } |
| |
| return TargetLoweringObjectFile:: |
| getExprForDwarfReference(SSym, Mang, MMI, |
| Encoding & ~dwarf::DW_EH_PE_indirect, Streamer); |
| } |
| |
| return TargetLoweringObjectFile:: |
| getExprForDwarfGlobalReference(GV, Mang, MMI, Encoding, Streamer); |
| } |
| |
| unsigned TargetLoweringObjectFileMachO::getPersonalityEncoding() const { |
| return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4; |
| } |
| |
| unsigned TargetLoweringObjectFileMachO::getLSDAEncoding() const { |
| return DW_EH_PE_pcrel; |
| } |
| |
| unsigned TargetLoweringObjectFileMachO::getFDEEncoding() const { |
| return DW_EH_PE_pcrel; |
| } |
| |
| unsigned TargetLoweringObjectFileMachO::getTTypeEncoding() const { |
| return DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // COFF |
| //===----------------------------------------------------------------------===// |
| |
| void TargetLoweringObjectFileCOFF::Initialize(MCContext &Ctx, |
| const TargetMachine &TM) { |
| TargetLoweringObjectFile::Initialize(Ctx, TM); |
| TextSection = |
| getContext().getCOFFSection(".text", |
| COFF::IMAGE_SCN_CNT_CODE | |
| COFF::IMAGE_SCN_MEM_EXECUTE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getText()); |
| DataSection = |
| getContext().getCOFFSection(".data", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE, |
| SectionKind::getDataRel()); |
| ReadOnlySection = |
| getContext().getCOFFSection(".rdata", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getReadOnly()); |
| StaticCtorSection = |
| getContext().getCOFFSection(".ctors", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE, |
| SectionKind::getDataRel()); |
| StaticDtorSection = |
| getContext().getCOFFSection(".dtors", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE, |
| 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 = |
| getContext().getCOFFSection(".gcc_except_table", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getReadOnly()); |
| // Debug info. |
| DwarfAbbrevSection = |
| getContext().getCOFFSection(".debug_abbrev", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfInfoSection = |
| getContext().getCOFFSection(".debug_info", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfLineSection = |
| getContext().getCOFFSection(".debug_line", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfFrameSection = |
| getContext().getCOFFSection(".debug_frame", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfPubNamesSection = |
| getContext().getCOFFSection(".debug_pubnames", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfPubTypesSection = |
| getContext().getCOFFSection(".debug_pubtypes", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfStrSection = |
| getContext().getCOFFSection(".debug_str", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfLocSection = |
| getContext().getCOFFSection(".debug_loc", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfARangesSection = |
| getContext().getCOFFSection(".debug_aranges", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfRangesSection = |
| getContext().getCOFFSection(".debug_ranges", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| DwarfMacroInfoSection = |
| getContext().getCOFFSection(".debug_macinfo", |
| COFF::IMAGE_SCN_MEM_DISCARDABLE | |
| COFF::IMAGE_SCN_MEM_READ, |
| SectionKind::getMetadata()); |
| |
| DrectveSection = |
| getContext().getCOFFSection(".drectve", |
| COFF::IMAGE_SCN_LNK_INFO, |
| SectionKind::getMetadata()); |
| } |
| |
| const MCSection *TargetLoweringObjectFileCOFF::getEHFrameSection() const { |
| return getContext().getCOFFSection(".eh_frame", |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE, |
| SectionKind::getDataRel()); |
| } |
| |
| |
| static unsigned |
| getCOFFSectionFlags(SectionKind K) { |
| unsigned Flags = 0; |
| |
| if (K.isMetadata()) |
| Flags |= |
| COFF::IMAGE_SCN_MEM_DISCARDABLE; |
| else if (K.isText()) |
| Flags |= |
| COFF::IMAGE_SCN_MEM_EXECUTE | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_CNT_CODE; |
| else if (K.isBSS ()) |
| Flags |= |
| COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE; |
| else if (K.isReadOnly()) |
| Flags |= |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ; |
| else if (K.isWriteable()) |
| Flags |= |
| COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | |
| COFF::IMAGE_SCN_MEM_READ | |
| COFF::IMAGE_SCN_MEM_WRITE; |
| |
| return Flags; |
| } |
| |
| const MCSection *TargetLoweringObjectFileCOFF:: |
| getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind, |
| Mangler *Mang, const TargetMachine &TM) const { |
| return getContext().getCOFFSection(GV->getSection(), |
| getCOFFSectionFlags(Kind), |
| Kind); |
| } |
| |
| static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) { |
| if (Kind.isText()) |
| return ".text$"; |
| if (Kind.isBSS ()) |
| return ".bss$"; |
| if (Kind.isWriteable()) |
| return ".data$"; |
| return ".rdata$"; |
| } |
| |
| |
| 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)); |
| MCSymbol *Sym = Mang->getSymbol(GV); |
| Name.append(Sym->getName().begin() + 1, Sym->getName().end()); |
| |
| unsigned Characteristics = getCOFFSectionFlags(Kind); |
| |
| Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT; |
| |
| return getContext().getCOFFSection(Name.str(), Characteristics, |
| COFF::IMAGE_COMDAT_SELECT_ANY, Kind); |
| } |
| |
| if (Kind.isText()) |
| return getTextSection(); |
| |
| return getDataSection(); |
| } |
| |
