//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetLoweringObjectFile.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.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/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/Target/TargetLowering.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// Generic Code
//===----------------------------------------------------------------------===//
-TargetLoweringObjectFile::TargetLoweringObjectFile() : Ctx(0) {
- TextSection = 0;
- DataSection = 0;
- BSSSection = 0;
- ReadOnlySection = 0;
- StaticCtorSection = 0;
- StaticDtorSection = 0;
- LSDASection = 0;
- EHFrameSection = 0;
-
- DwarfAbbrevSection = 0;
- DwarfInfoSection = 0;
- DwarfLineSection = 0;
- DwarfFrameSection = 0;
- DwarfPubNamesSection = 0;
- DwarfPubTypesSection = 0;
- DwarfDebugInlineSection = 0;
- DwarfStrSection = 0;
- DwarfLocSection = 0;
- DwarfARangesSection = 0;
- DwarfRangesSection = 0;
- DwarfMacroInfoSection = 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;
// 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.
/// 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.
+/// 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) {
- const ArrayType *ATy = cast<ArrayType>(C->getType());
-
- // First check: is we have constant array of i8 terminated with zero
- if (const ConstantArray *CVA = dyn_cast<ConstantArray>(C)) {
- if (ATy->getNumElements() == 0) return false;
-
- ConstantInt *Null =
- dyn_cast<ConstantInt>(CVA->getOperand(ATy->getNumElements()-1));
- if (Null == 0 || Null->getZExtValue() != 0)
+ // 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, e = ATy->getNumElements()-1; i != e; ++i)
- // Reject constantexpr elements etc.
- if (!isa<ConstantInt>(CVA->getOperand(i)) ||
- CVA->getOperand(i) == Null)
+ 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))
- return ATy->getNumElements() == 1;
+ return cast<ArrayType>(C->getType())->getNumElements() == 1;
return false;
}
+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
// Early exit - functions should be always in text sections.
const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
- if (GVar == 0)
+ if (!GVar)
return SectionKind::getText();
// Handle thread-local data first.
if (GVar->isThreadLocal()) {
- if (isSuitableForBSS(GVar))
+ if (isSuitableForBSS(GVar, TM.Options.NoZerosInBSS))
return SectionKind::getThreadBSS();
return SectionKind::getThreadData();
}
return SectionKind::getCommon();
// Variable can be easily put to BSS section.
- if (isSuitableForBSS(GVar)) {
+ if (isSuitableForBSS(GVar, TM.Options.NoZerosInBSS)) {
if (GVar->hasLocalLinkage())
return SectionKind::getBSSLocal();
else if (GVar->hasExternalLinkage())
return SectionKind::getBSS();
}
- Constant *C = GVar->getInitializer();
+ const 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: assert(0 && "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 of the right width.
- if (
const ArrayType *ATy = dyn_cast<ArrayType>(C->getType())) {
- if (const IntegerType *ITy =
+ 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) &&
// 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())) {
+ 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::getMergeableConst();
- }
-
- 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)
+ default:
return SectionKind::getReadOnly();
+ }
- // Otherwise, the dynamic linker needs to fix it up, put it in the
- // writable data.rel.local section.
- return SectionKind::getReadOnlyWithRelLocal();
-
- 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
// globals together onto fewer pages, improving the locality of the dynamic
// linker.
if (ReloModel == Reloc::Static)
- return SectionKind::getDataNoRel();
-
- switch (C->getRelocationInfo()) {
- default: assert(0 && "unknown relocation info kind");
- case Constant::NoRelocation:
- return SectionKind::getDataNoRel();
- case Constant::LocalRelocation:
- return SectionKind::getDataRelLocal();
- case Constant::GlobalRelocations:
- return SectionKind::getDataRel();
- }
+ return SectionKind::getData();
+
+ if (C->needsRelocation())
+ return SectionKind::getData();
+ return SectionKind::getData();
}
-/// 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 MCSection *TargetLoweringObjectFile::
-SectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler *Mang,
- const TargetMachine &TM) const {
+/// 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);
return SelectSectionForGlobal(GV, Kind, Mang, TM);
}
+MCSection *TargetLoweringObjectFile::getSectionForJumpTable(
+ const Function &F, Mangler &Mang, const TargetMachine &TM) const {
+ return getSectionForConstant(F.getParent()->getDataLayout(),
+ SectionKind::getReadOnly(), /*C=*/nullptr);
+}
-// Lame default implementation. Calculate the section name for global.
-const MCSection *
-TargetLoweringObjectFile::SelectSectionForGlobal(const GlobalValue *GV,
- SectionKind Kind,
- Mangler *Mang,
- const TargetMachine &TM) const{
- assert(!Kind.isThreadLocal() && "Doesn't support TLS");
-
- if (Kind.isText())
- return getTextSection();
-
- if (Kind.isBSS() && BSSSection != 0)
- return BSSSection;
+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;
- if (Kind.isReadOnly() && ReadOnlySection != 0)
- return ReadOnlySection;
+ // 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;
- return getDataSection();
+ return false;
}
-/// getSectionForConstant - Given a mergable constant with the
-/// specified size and relocation information, return a section that it
-/// should be placed in.
-const MCSection *
-TargetLoweringObjectFile::getSectionForConstant(SectionKind Kind) const {
- if (Kind.isReadOnly() && ReadOnlySection != 0)
+/// 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;
return DataSection;
}
-/// getSymbolForDwarfGlobalReference - Return an MCExpr to use for a
+/// getTTypeGlobalReference - Return an MCExpr to use for a
/// reference to the specified global variable from exception
/// handling information.
-const MCExpr *TargetLoweringObjectFile::
-getSymbolForDwarfGlobalReference(const GlobalValue *GV, Mangler *Mang,
- MachineModuleInfo *MMI, unsigned Encoding) const {
- // FIXME: Use GetGlobalValueSymbol.
- SmallString<128> Name;
- Mang->getNameWithPrefix(Name, GV, false);
- const MCSymbol *Sym;
-
- if (GV->hasPrivateLinkage())
- Sym = getContext().GetOrCreateTemporarySymbol(Name.str());
- else
- Sym = getContext().GetOrCreateSymbol(Name.str());
-
- return getSymbolForDwarfReference(Sym, MMI, Encoding);
+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);
}
const MCExpr *TargetLoweringObjectFile::
-getSymbolForDwarfReference(const MCSymbol *Sym, MachineModuleInfo *MMI,
- unsigned Encoding) const {
- const MCExpr *Res = MCSymbolRefExpr::Create(Sym, getContext());
-
- switch (Encoding & 0xF0) {
+getTTypeReference(const MCSymbolRefExpr *Sym, unsigned Encoding,
+ MCStreamer &Streamer) const {
+ switch (Encoding & 0x70) {
default:
- llvm_report_error("We do not support this DWARF encoding yet!");
- break;
+ report_fatal_error("We do not support this DWARF encoding yet!");
case dwarf::DW_EH_PE_absptr:
// Do nothing special
- break;
- case dwarf::DW_EH_PE_pcrel:
- // FIXME: PCSymbol
- const MCExpr *PC = MCSymbolRefExpr::Create(".", getContext());
- Res = MCBinaryExpr::CreateSub(Res, PC, getContext());
- break;
+ 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());
+ }
}
-
- return Res;
-}
-
-unsigned TargetLoweringObjectFile::getPersonalityEncoding() const {
- return dwarf::DW_EH_PE_absptr;
-}
-
-unsigned TargetLoweringObjectFile::getLSDAEncoding() const {
- return dwarf::DW_EH_PE_absptr;
}
-unsigned TargetLoweringObjectFile::getFDEEncoding() const {
- return dwarf::DW_EH_PE_absptr;
+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);
}
-unsigned TargetLoweringObjectFile::getTTypeEncoding() const {
- return dwarf::DW_EH_PE_absptr;
+void TargetLoweringObjectFile::getNameWithPrefix(
+ SmallVectorImpl<char> &OutName, const GlobalValue *GV, Mangler &Mang,
+ const TargetMachine &TM) const {
+ Mang.getNameWithPrefix(OutName, GV, /*CannotUsePrivateLabel=*/false);
}
-
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