//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetLoweringObjectFile.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/GlobalVariable.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Mangler.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetOptions.h"
-#include "llvm/ADT/StringExtras.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Generic Code
//===----------------------------------------------------------------------===//
-TargetLoweringObjectFile::TargetLoweringObjectFile() {
- TextSection = 0;
- DataSection = 0;
- BSSSection_ = 0;
- ReadOnlySection = 0;
- TLSDataSection = 0;
- TLSBSSSection = 0;
- CStringSection_ = 0;
+/// Initialize - this method must be called before any actual lowering is
+/// done. This specifies the current context for codegen, and gives the
+/// lowering implementations a chance to set up their default sections.
+void TargetLoweringObjectFile::Initialize(MCContext &ctx,
+ const TargetMachine &TM) {
+ Ctx = &ctx;
+ InitMCObjectFileInfo(TM.getTargetTriple(), TM.getRelocationModel(),
+ TM.getCodeModel(), *Ctx);
}
TargetLoweringObjectFile::~TargetLoweringObjectFile() {
}
-static bool isSuitableForBSS(const GlobalVariable *GV) {
- Constant *C = GV->getInitializer();
-
+static bool isSuitableForBSS(const GlobalVariable *GV, bool NoZerosInBSS) {
+ const Constant *C = GV->getInitializer();
+
// Must have zero initializer.
if (!C->isNullValue())
return false;
-
+
// Leave constant zeros in readonly constant sections, so they can be shared.
if (GV->isConstant())
return false;
-
+
// If the global has an explicit section specified, don't put it in BSS.
- if (!GV->getSection().empty())
+ if (GV->hasSection())
return false;
-
+
// If -nozero-initialized-in-bss is specified, don't ever use BSS.
if (NoZerosInBSS)
return false;
-
+
// Otherwise, put it in BSS!
return true;
}
-static bool isConstantString(const Constant *C) {
- // First check: is we have constant array of i8 terminated with zero
- const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
- // Check, if initializer is a null-terminated string
- if (CVA && CVA->isCString())
+/// IsNullTerminatedString - Return true if the specified constant (which is
+/// known to have a type that is an array of 1/2/4 byte elements) ends with a
+/// nul value and contains no other nuls in it. Note that this is more general
+/// than ConstantDataSequential::isString because we allow 2 & 4 byte strings.
+static bool IsNullTerminatedString(const Constant *C) {
+ // First check: is we have constant array terminated with zero
+ if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(C)) {
+ unsigned NumElts = CDS->getNumElements();
+ assert(NumElts != 0 && "Can't have an empty CDS");
+
+ if (CDS->getElementAsInteger(NumElts-1) != 0)
+ return false; // Not null terminated.
+
+ // Verify that the null doesn't occur anywhere else in the string.
+ for (unsigned i = 0; i != NumElts-1; ++i)
+ if (CDS->getElementAsInteger(i) == 0)
+ return false;
return true;
+ }
// Another possibility: [1 x i8] zeroinitializer
if (isa<ConstantAggregateZero>(C))
- if (const ArrayType *Ty = dyn_cast<ArrayType>(C->getType()))
- return (Ty->getElementType() == Type::Int8Ty &&
- Ty->getNumElements() == 1);
+ return cast<ArrayType>(C->getType())->getNumElements() == 1;
return false;
}
-static SectionKind::Kind SectionKindForGlobal(const GlobalValue *GV,
- const TargetMachine &TM) {
+MCSymbol *TargetLoweringObjectFile::getSymbolWithGlobalValueBase(
+ const GlobalValue *GV, StringRef Suffix, Mangler &Mang,
+ const TargetMachine &TM) const {
+ assert(!Suffix.empty());
+
+ SmallString<60> NameStr;
+ NameStr += GV->getParent()->getDataLayout().getPrivateGlobalPrefix();
+ TM.getNameWithPrefix(NameStr, GV, Mang);
+ NameStr.append(Suffix.begin(), Suffix.end());
+ return Ctx->getOrCreateSymbol(NameStr);
+}
+
+MCSymbol *TargetLoweringObjectFile::getCFIPersonalitySymbol(
+ const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
+ MachineModuleInfo *MMI) const {
+ return TM.getSymbol(GV, Mang);
+}
+
+void TargetLoweringObjectFile::emitPersonalityValue(MCStreamer &Streamer,
+ const DataLayout &,
+ const MCSymbol *Sym) const {
+}
+
+
+/// getKindForGlobal - This is a top-level target-independent classifier for
+/// a global variable. Given an global variable and information from TM, it
+/// classifies the global in a variety of ways that make various target
+/// implementations simpler. The target implementation is free to ignore this
+/// extra info of course.
+SectionKind TargetLoweringObjectFile::getKindForGlobal(const GlobalValue *GV,
+ const TargetMachine &TM){
+ assert(!GV->isDeclaration() && !GV->hasAvailableExternallyLinkage() &&
+ "Can only be used for global definitions");
+
Reloc::Model ReloModel = TM.getRelocationModel();
-
+
// Early exit - functions should be always in text sections.
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
- if (GVar == 0)
- return SectionKind::Text;
+ if (!GVar)
+ return SectionKind::getText();
-
// Handle thread-local data first.
if (GVar->isThreadLocal()) {
- if (isSuitableForBSS(GVar))
- return SectionKind::ThreadBSS;
- return SectionKind::ThreadData;
+ if (isSuitableForBSS(GVar, TM.Options.NoZerosInBSS))
+ return SectionKind::getThreadBSS();
+ return SectionKind::getThreadData();
}
+ // Variables with common linkage always get classified as common.
+ if (GVar->hasCommonLinkage())
+ return SectionKind::getCommon();
+
// Variable can be easily put to BSS section.
- if (isSuitableForBSS(GVar))
- return SectionKind::BSS;
+ if (isSuitableForBSS(GVar, TM.Options.NoZerosInBSS)) {
+ if (GVar->hasLocalLinkage())
+ return SectionKind::getBSSLocal();
+ else if (GVar->hasExternalLinkage())
+ return SectionKind::getBSSExtern();
+ return SectionKind::getBSS();
+ }
+
+ const Constant *C = GVar->getInitializer();
- Constant *C = GVar->getInitializer();
-
// If the global is marked constant, we can put it into a mergable section,
// a mergable string section, or general .data if it contains relocations.
if (GVar->isConstant()) {
// If the initializer for the global contains something that requires a
- // relocation, then we may have to drop this into a wriable data section
+ // relocation, then we may have to drop this into a writable data section
// even though it is marked const.
- switch (C->getRelocationInfo()) {
- default: llvm_unreachable("unknown relocation info kind");
- case Constant::NoRelocation:
+ if (!C->needsRelocation()) {
+ // If the global is required to have a unique address, it can't be put
+ // into a mergable section: just drop it into the general read-only
+ // section instead.
+ if (!GVar->hasUnnamedAddr())
+ return SectionKind::getReadOnly();
+
// If initializer is a null-terminated string, put it in a "cstring"
- // section if the target has it.
- if (isConstantString(C))
- return SectionKind::MergeableCString;
-
+ // section of the right width.
+ if (ArrayType *ATy = dyn_cast<ArrayType>(C->getType())) {
+ if (IntegerType *ITy =
+ dyn_cast<IntegerType>(ATy->getElementType())) {
+ if ((ITy->getBitWidth() == 8 || ITy->getBitWidth() == 16 ||
+ ITy->getBitWidth() == 32) &&
+ IsNullTerminatedString(C)) {
+ if (ITy->getBitWidth() == 8)
+ return SectionKind::getMergeable1ByteCString();
+ if (ITy->getBitWidth() == 16)
+ return SectionKind::getMergeable2ByteCString();
+
+ assert(ITy->getBitWidth() == 32 && "Unknown width");
+ return SectionKind::getMergeable4ByteCString();
+ }
+ }
+ }
+
// Otherwise, just drop it into a mergable constant section. If we have
// a section for this size, use it, otherwise use the arbitrary sized
// mergable section.
- switch (TM.getTargetData()->getTypeAllocSize(C->getType())) {
- case 4: return SectionKind::MergeableConst4;
- case 8: return SectionKind::MergeableConst8;
- case 16: return SectionKind::MergeableConst16;
- default: return SectionKind::MergeableConst;
+ switch (GV->getParent()->getDataLayout().getTypeAllocSize(C->getType())) {
+ case 4: return SectionKind::getMergeableConst4();
+ case 8: return SectionKind::getMergeableConst8();
+ case 16: return SectionKind::getMergeableConst16();
+ default:
+ return SectionKind::getReadOnly();
}
-
- case Constant::LocalRelocation:
- // In static relocation model, the linker will resolve all addresses, so
- // the relocation entries will actually be constants by the time the app
- // starts up. However, we can't put this into a mergable section, because
- // the linker doesn't take relocations into consideration when it tries to
- // merge entries in the section.
- if (ReloModel == Reloc::Static)
- return SectionKind::ReadOnly;
-
- // Otherwise, the dynamic linker needs to fix it up, put it in the
- // writable data.rel.local section.
- return SectionKind::ReadOnlyWithRelLocal;
-
- case Constant::GlobalRelocations:
+
+ } else {
// In static relocation model, the linker will resolve all addresses, so
// the relocation entries will actually be constants by the time the app
// starts up. However, we can't put this into a mergable section, because
// the linker doesn't take relocations into consideration when it tries to
// merge entries in the section.
if (ReloModel == Reloc::Static)
- return SectionKind::ReadOnly;
-
+ return SectionKind::getReadOnly();
+
// Otherwise, the dynamic linker needs to fix it up, put it in the
// writable data.rel section.
- return SectionKind::ReadOnlyWithRel;
+ return SectionKind::getReadOnlyWithRel();
}
}
// globals together onto fewer pages, improving the locality of the dynamic
// linker.
if (ReloModel == Reloc::Static)
- return SectionKind::DataNoRel;
-
- switch (C->getRelocationInfo()) {
- default: llvm_unreachable("unknown relocation info kind");
- case Constant::NoRelocation:
- return SectionKind::DataNoRel;
- case Constant::LocalRelocation:
- return SectionKind::DataRelLocal;
- case Constant::GlobalRelocations:
- return SectionKind::DataRel;
- }
-}
-
-/// SectionForGlobal - This method computes the appropriate section to emit
-/// the specified global variable or function definition. This should not
-/// be passed external (or available externally) globals.
-const Section *TargetLoweringObjectFile::
-SectionForGlobal(const GlobalValue *GV, const TargetMachine &TM) const {
- assert(!GV->isDeclaration() && !GV->hasAvailableExternallyLinkage() &&
- "Can only be used for global definitions");
-
- SectionKind::Kind GVKind = SectionKindForGlobal(GV, TM);
-
- SectionKind Kind = SectionKind::get(GVKind, GV->isWeakForLinker(),
- GV->hasSection());
-
-
- // Select section name.
- if (GV->hasSection()) {
- // If the target has special section hacks for specifically named globals,
- // return them now.
- if (const Section *TS = getSpecialCasedSectionGlobals(GV, Kind))
- return TS;
-
- // If the target has magic semantics for certain section names, make sure to
- // pick up the flags. This allows the user to write things with attribute
- // section and still get the appropriate section flags printed.
- GVKind = getKindForNamedSection(GV->getSection().c_str(), GVKind);
-
- return getOrCreateSection(GV->getSection().c_str(), false, GVKind);
- }
-
-
- // Use default section depending on the 'type' of global
- return SelectSectionForGlobal(GV, Kind, TM);
-}
-
-// Lame default implementation. Calculate the section name for global.
-const Section*
-TargetLoweringObjectFile::SelectSectionForGlobal(const GlobalValue *GV,
- SectionKind Kind,
- const TargetMachine &TM) const{
- assert(!Kind.isThreadLocal() && "Doesn't support TLS");
-
- if (Kind.isText())
- return getTextSection();
-
- if (Kind.isBSS() && BSSSection_ != 0)
- return BSSSection_;
-
- if (Kind.isReadOnly() && ReadOnlySection != 0)
- return ReadOnlySection;
-
- return getDataSection();
-}
-
-/// getSectionForMergableConstant - Given a mergable constant with the
-/// specified size and relocation information, return a section that it
-/// should be placed in.
-const Section *
-TargetLoweringObjectFile::
-getSectionForMergeableConstant(SectionKind Kind) const {
- if (Kind.isReadOnly() && ReadOnlySection != 0)
- return ReadOnlySection;
-
- return DataSection;
-}
-
-
-const Section *TargetLoweringObjectFile::
-getOrCreateSection(const char *Name, bool isDirective,
- SectionKind::Kind Kind) const {
- Section &S = Sections[Name];
-
- // This is newly-created section, set it up properly.
- if (S.Name.empty()) {
- S.Kind = SectionKind::get(Kind, false /*weak*/, !isDirective);
- S.Name = Name;
- }
+ return SectionKind::getData();
- return &S;
+ if (C->needsRelocation())
+ return SectionKind::getData();
+ return SectionKind::getData();
}
+/// This method computes the appropriate section to emit the specified global
+/// variable or function definition. This should not be passed external (or
+/// available externally) globals.
+MCSection *
+TargetLoweringObjectFile::SectionForGlobal(const GlobalValue *GV,
+ SectionKind Kind, Mangler &Mang,
+ const TargetMachine &TM) const {
+ // Select section name.
+ if (GV->hasSection())
+ return getExplicitSectionGlobal(GV, Kind, Mang, TM);
-//===----------------------------------------------------------------------===//
-// ELF
-//===----------------------------------------------------------------------===//
-
-TargetLoweringObjectFileELF::TargetLoweringObjectFileELF(bool atIsCommentChar,
- bool HasCrazyBSS)
- : AtIsCommentChar(atIsCommentChar) {
-
- if (!HasCrazyBSS)
- BSSSection_ = getOrCreateSection("\t.bss", true, SectionKind::BSS);
- else
- // PPC/Linux doesn't support the .bss directive, it needs .section .bss.
- // FIXME: Does .section .bss work everywhere??
- BSSSection_ = getOrCreateSection("\t.bss", false, SectionKind::BSS);
-
-
- TextSection = getOrCreateSection("\t.text", true, SectionKind::Text);
- DataSection = getOrCreateSection("\t.data", true, SectionKind::DataRel);
- ReadOnlySection =
- getOrCreateSection("\t.rodata", false, SectionKind::ReadOnly);
- TLSDataSection =
- getOrCreateSection("\t.tdata", false, SectionKind::ThreadData);
- CStringSection_ = getOrCreateSection("\t.rodata.str", true,
- SectionKind::MergeableCString);
-
- TLSBSSSection = getOrCreateSection("\t.tbss", false, SectionKind::ThreadBSS);
-
- DataRelSection = getOrCreateSection("\t.data.rel", false,
- SectionKind::DataRel);
- DataRelLocalSection = getOrCreateSection("\t.data.rel.local", false,
- SectionKind::DataRelLocal);
- DataRelROSection = getOrCreateSection("\t.data.rel.ro", false,
- SectionKind::ReadOnlyWithRel);
- DataRelROLocalSection =
- getOrCreateSection("\t.data.rel.ro.local", false,
- SectionKind::ReadOnlyWithRelLocal);
-
- MergeableConst4Section = getOrCreateSection(".rodata.cst4", false,
- SectionKind::MergeableConst4);
- MergeableConst8Section = getOrCreateSection(".rodata.cst8", false,
- SectionKind::MergeableConst8);
- MergeableConst16Section = getOrCreateSection(".rodata.cst16", false,
- SectionKind::MergeableConst16);
-}
-
-
-SectionKind::Kind TargetLoweringObjectFileELF::
-getKindForNamedSection(const char *Name, SectionKind::Kind K) const {
- if (Name[0] != '.') return K;
-
- // Some lame default implementation based on some magic section names.
- if (strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
- strncmp(Name, ".llvm.linkonce.b.", 17) == 0 ||
- strncmp(Name, ".gnu.linkonce.sb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.sb.", 18) == 0)
- return SectionKind::BSS;
-
- if (strcmp(Name, ".tdata") == 0 ||
- strncmp(Name, ".tdata.", 7) == 0 ||
- strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
- return SectionKind::ThreadData;
-
- if (strcmp(Name, ".tbss") == 0 ||
- strncmp(Name, ".tbss.", 6) == 0 ||
- strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
- return SectionKind::ThreadBSS;
-
- return K;
-}
-
-void TargetLoweringObjectFileELF::
-getSectionFlagsAsString(SectionKind Kind, SmallVectorImpl<char> &Str) const {
- Str.push_back(',');
- Str.push_back('"');
-
- if (!Kind.isMetadata())
- Str.push_back('a');
- if (Kind.isText())
- Str.push_back('x');
- if (Kind.isWriteable())
- Str.push_back('w');
- if (Kind.isMergeableConst() || Kind.isMergeableCString())
- Str.push_back('M');
- if (Kind.isMergeableCString())
- Str.push_back('S');
- if (Kind.isThreadLocal())
- Str.push_back('T');
-
- Str.push_back('"');
- Str.push_back(',');
-
- // If comment string is '@', e.g. as on ARM - use '%' instead
- if (AtIsCommentChar)
- Str.push_back('%');
- else
- Str.push_back('@');
-
- const char *KindStr;
- if (Kind.isBSS() || Kind.isThreadBSS())
- KindStr = "nobits";
- else
- KindStr = "progbits";
-
- Str.append(KindStr, KindStr+strlen(KindStr));
-
- if (Kind.isMergeableCString()) {
- // TODO: Eventually handle multiple byte character strings. For now, all
- // mergable C strings are single byte.
- Str.push_back(',');
- Str.push_back('1');
- } else if (Kind.isMergeableConst4()) {
- Str.push_back(',');
- Str.push_back('4');
- } else if (Kind.isMergeableConst8()) {
- Str.push_back(',');
- Str.push_back('8');
- } else if (Kind.isMergeableConst16()) {
- Str.push_back(',');
- Str.push_back('1');
- Str.push_back('6');
- }
-}
-
-
-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.isBSS()) return ".gnu.linkonce.b.";
- 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.";
+ // Use default section depending on the 'type' of global
+ return SelectSectionForGlobal(GV, Kind, Mang, TM);
}
-const Section *TargetLoweringObjectFileELF::
-SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
- 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 (Kind.isWeak()) {
- const char *Prefix = getSectionPrefixForUniqueGlobal(Kind);
- // FIXME: Use mangler interface (PR4584).
- std::string Name = Prefix+GV->getNameStr();
- return getOrCreateSection(Name.c_str(), false, Kind.getKind());
- }
-
- if (Kind.isText()) return TextSection;
- if (Kind.isMergeableCString()) {
- assert(CStringSection_ && "Should have string section prefix");
-
- // 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));
-
- std::string Name = CStringSection_->getName() + utostr(Size) + '.' +
- utostr(Align);
- return getOrCreateSection(Name.c_str(), false,
- SectionKind::MergeableCString);
- }
-
- if (Kind.isMergeableConst()) {
- if (Kind.isMergeableConst4())
- return MergeableConst4Section;
- if (Kind.isMergeableConst8())
- return MergeableConst8Section;
- if (Kind.isMergeableConst16())
- return MergeableConst16Section;
- return ReadOnlySection; // .const
- }
-
- if (Kind.isReadOnly()) return ReadOnlySection;
-
- if (Kind.isThreadData()) return TLSDataSection;
- if (Kind.isThreadBSS()) return TLSBSSSection;
-
- if (Kind.isBSS()) 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;
+MCSection *TargetLoweringObjectFile::getSectionForJumpTable(
+ const Function &F, Mangler &Mang, const TargetMachine &TM) const {
+ return getSectionForConstant(F.getParent()->getDataLayout(),
+ SectionKind::getReadOnly(), /*C=*/nullptr);
}
-/// getSectionForMergeableConstant - Given a mergeable constant with the
-/// specified size and relocation information, return a section that it
-/// should be placed in.
-const Section *TargetLoweringObjectFileELF::
-getSectionForMergeableConstant(SectionKind Kind) const {
- if (Kind.isMergeableConst4())
- return MergeableConst4Section;
- if (Kind.isMergeableConst8())
- return MergeableConst8Section;
- if (Kind.isMergeableConst16())
- return MergeableConst16Section;
- if (Kind.isReadOnly())
- return ReadOnlySection;
-
- if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection;
- assert(Kind.isReadOnlyWithRel() && "Unknown section kind");
- return DataRelROSection;
-}
+bool TargetLoweringObjectFile::shouldPutJumpTableInFunctionSection(
+ bool UsesLabelDifference, const Function &F) const {
+ // In PIC mode, we need to emit the jump table to the same section as the
+ // function body itself, otherwise the label differences won't make sense.
+ // FIXME: Need a better predicate for this: what about custom entries?
+ if (UsesLabelDifference)
+ return true;
-//===----------------------------------------------------------------------===//
-// MachO
-//===----------------------------------------------------------------------===//
+ // We should also do if the section name is NULL or function is declared
+ // in discardable section
+ // FIXME: this isn't the right predicate, should be based on the MCSection
+ // for the function.
+ if (F.isWeakForLinker())
+ return true;
-TargetLoweringObjectFileMachO::
-TargetLoweringObjectFileMachO(const TargetMachine &TM) {
- TextSection = getOrCreateSection("\t.text", true, SectionKind::Text);
- DataSection = getOrCreateSection("\t.data", true, SectionKind::DataRel);
-
- CStringSection_ = getOrCreateSection("\t.cstring", true,
- SectionKind::MergeableCString);
- FourByteConstantSection = getOrCreateSection("\t.literal4\n", true,
- SectionKind::MergeableConst4);
- EightByteConstantSection = getOrCreateSection("\t.literal8\n", true,
- SectionKind::MergeableConst8);
-
- // ld_classic doesn't support .literal16 in 32-bit mode, and ld64 falls back
- // to using it in -static mode.
- if (TM.getRelocationModel() != Reloc::Static &&
- TM.getTargetData()->getPointerSize() == 32)
- SixteenByteConstantSection =
- getOrCreateSection("\t.literal16\n", true, SectionKind::MergeableConst16);
- else
- SixteenByteConstantSection = 0;
-
- ReadOnlySection = getOrCreateSection("\t.const", true, SectionKind::ReadOnly);
-
- TextCoalSection =
- getOrCreateSection("\t__TEXT,__textcoal_nt,coalesced,pure_instructions",
- false, SectionKind::Text);
- ConstTextCoalSection = getOrCreateSection("\t__TEXT,__const_coal,coalesced",
- false, SectionKind::Text);
- ConstDataCoalSection = getOrCreateSection("\t__DATA,__const_coal,coalesced",
- false, SectionKind::Text);
- ConstDataSection = getOrCreateSection("\t.const_data", true,
- SectionKind::ReadOnlyWithRel);
- DataCoalSection = getOrCreateSection("\t__DATA,__datacoal_nt,coalesced",
- false, SectionKind::DataRel);
+ return false;
}
-const Section *
-TargetLoweringObjectFileMachO::SelectSectionForGlobal(const GlobalValue *GV,
- SectionKind Kind,
- const TargetMachine &TM) const {
- assert(!Kind.isThreadLocal() && "Darwin doesn't support TLS");
-
- if (Kind.isText())
- return Kind.isWeak() ? 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 (Kind.isWeak()) {
- if (Kind.isReadOnly())
- return ConstTextCoalSection;
- return DataCoalSection;
- }
-
- // FIXME: Alignment check should be handled by section classifier.
- if (Kind.isMergeableCString()) {
- Constant *C = cast<GlobalVariable>(GV)->getInitializer();
- const Type *Ty = cast<ArrayType>(C->getType())->getElementType();
- const TargetData &TD = *TM.getTargetData();
- unsigned Size = TD.getTypeAllocSize(Ty);
- if (Size) {
- unsigned Align = TD.getPreferredAlignment(cast<GlobalVariable>(GV));
- if (Align <= 32)
- return CStringSection_;
- }
-
- return ReadOnlySection;
- }
-
- if (Kind.isMergeableConst()) {
- if (Kind.isMergeableConst4())
- return FourByteConstantSection;
- if (Kind.isMergeableConst8())
- return EightByteConstantSection;
- if (Kind.isMergeableConst16() && SixteenByteConstantSection)
- return SixteenByteConstantSection;
- return ReadOnlySection; // .const
- }
-
- // FIXME: ROData -> const in -static mode that is relocatable but they happen
- // by the static linker. Why not mergeable?
- if (Kind.isReadOnly())
+/// Given a mergable constant with the specified size and relocation
+/// information, return a section that it should be placed in.
+MCSection *TargetLoweringObjectFile::getSectionForConstant(
+ const DataLayout &DL, SectionKind Kind, const Constant *C) const {
+ if (Kind.isReadOnly() && ReadOnlySection != nullptr)
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;
-
- // Otherwise, just drop the variable in the normal data section.
return DataSection;
}
-const Section *
-TargetLoweringObjectFileMachO::
-getSectionForMergeableConstant(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())
- return ConstDataSection;
-
- if (Kind.isMergeableConst4())
- return FourByteConstantSection;
- if (Kind.isMergeableConst8())
- return EightByteConstantSection;
- if (Kind.isMergeableConst16() && SixteenByteConstantSection)
- return SixteenByteConstantSection;
- return ReadOnlySection; // .const
-}
-
-//===----------------------------------------------------------------------===//
-// COFF
-//===----------------------------------------------------------------------===//
-
-TargetLoweringObjectFileCOFF::TargetLoweringObjectFileCOFF() {
- TextSection = getOrCreateSection("_text", true, SectionKind::Text);
- DataSection = getOrCreateSection("_data", true, SectionKind::DataRel);
+/// getTTypeGlobalReference - Return an MCExpr to use for a
+/// reference to the specified global variable from exception
+/// handling information.
+const MCExpr *TargetLoweringObjectFile::getTTypeGlobalReference(
+ const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
+ const TargetMachine &TM, MachineModuleInfo *MMI,
+ MCStreamer &Streamer) const {
+ const MCSymbolRefExpr *Ref =
+ MCSymbolRefExpr::create(TM.getSymbol(GV, Mang), getContext());
+
+ return getTTypeReference(Ref, Encoding, Streamer);
}
-void TargetLoweringObjectFileCOFF::
-getSectionFlagsAsString(SectionKind Kind, SmallVectorImpl<char> &Str) const {
- // FIXME: Inefficient.
- std::string Res = ",\"";
- if (Kind.isText())
- Res += 'x';
- if (Kind.isWriteable())
- Res += 'w';
- Res += "\"";
-
- Str.append(Res.begin(), Res.end());
+const MCExpr *TargetLoweringObjectFile::
+getTTypeReference(const MCSymbolRefExpr *Sym, unsigned Encoding,
+ MCStreamer &Streamer) const {
+ switch (Encoding & 0x70) {
+ default:
+ report_fatal_error("We do not support this DWARF encoding yet!");
+ case dwarf::DW_EH_PE_absptr:
+ // Do nothing special
+ return Sym;
+ case dwarf::DW_EH_PE_pcrel: {
+ // Emit a label to the streamer for the current position. This gives us
+ // .-foo addressing.
+ MCSymbol *PCSym = getContext().createTempSymbol();
+ Streamer.EmitLabel(PCSym);
+ const MCExpr *PC = MCSymbolRefExpr::create(PCSym, getContext());
+ return MCBinaryExpr::createSub(Sym, PC, getContext());
+ }
+ }
}
-static const char *getCOFFSectionPrefixForUniqueGlobal(SectionKind Kind) {
- if (Kind.isText())
- return ".text$linkonce";
- if (Kind.isWriteable())
- return ".data$linkonce";
- return ".rdata$linkonce";
+const MCExpr *TargetLoweringObjectFile::getDebugThreadLocalSymbol(const MCSymbol *Sym) const {
+ // FIXME: It's not clear what, if any, default this should have - perhaps a
+ // null return could mean 'no location' & we should just do that here.
+ return MCSymbolRefExpr::create(Sym, *Ctx);
}
-
-const Section *TargetLoweringObjectFileCOFF::
-SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
- 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 (Kind.isWeak()) {
- const char *Prefix = getCOFFSectionPrefixForUniqueGlobal(Kind);
- // FIXME: Use mangler interface (PR4584).
- std::string Name = Prefix+GV->getNameStr();
- return getOrCreateSection(Name.c_str(), false, Kind.getKind());
- }
-
- if (Kind.isText())
- return getTextSection();
-
- if (Kind.isBSS())
- if (const Section *S = BSSSection_)
- return S;
-
- if (Kind.isReadOnly() && ReadOnlySection != 0)
- return ReadOnlySection;
-
- return getDataSection();
+void TargetLoweringObjectFile::getNameWithPrefix(
+ SmallVectorImpl<char> &OutName, const GlobalValue *GV, Mangler &Mang,
+ const TargetMachine &TM) const {
+ Mang.getNameWithPrefix(OutName, GV, /*CannotUsePrivateLabel=*/false);
}
-
projects / oota-llvm.git / blobdiff