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mirror of https://github.com/RPCS3/llvm.git synced 2024-12-30 16:34:03 +00:00
llvm/lib/MC/MCStreamer.cpp
Reid Kleckner 16e4a624c4 [WinEH] Emit EH tables for __CxxFrameHandler3 on 32-bit x86
Small (really small!) C++ exception handling examples work on 32-bit x86
now.

This change disables the use of .seh_* directives in WinException when
CFI is not in use. It also uses absolute symbol references in the tables
instead of imagerel32 relocations.

Also fixes a cache invalidation bug in MMI personality classification.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-29 17:00:57 +00:00

698 lines
23 KiB
C++

//===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCStreamer.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCWin64EH.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
using namespace llvm;
// Pin the vtables to this file.
MCTargetStreamer::~MCTargetStreamer() {}
MCTargetStreamer::MCTargetStreamer(MCStreamer &S) : Streamer(S) {
S.setTargetStreamer(this);
}
void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
void MCTargetStreamer::finish() {}
void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
MCStreamer::MCStreamer(MCContext &Ctx)
: Context(Ctx), CurrentWinFrameInfo(nullptr) {
SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
}
MCStreamer::~MCStreamer() {
for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
delete WinFrameInfos[i];
}
void MCStreamer::reset() {
DwarfFrameInfos.clear();
for (unsigned i = 0; i < getNumWinFrameInfos(); ++i)
delete WinFrameInfos[i];
WinFrameInfos.clear();
CurrentWinFrameInfo = nullptr;
SymbolOrdering.clear();
SectionStack.clear();
SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
}
raw_ostream &MCStreamer::GetCommentOS() {
// By default, discard comments.
return nulls();
}
void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
for (auto &FI : DwarfFrameInfos)
FI.CompactUnwindEncoding =
(MAB ? MAB->generateCompactUnwindEncoding(FI.Instructions) : 0);
}
/// EmitIntValue - Special case of EmitValue that avoids the client having to
/// pass in a MCExpr for constant integers.
void MCStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
assert(1 <= Size && Size <= 8 && "Invalid size");
assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
"Invalid size");
char buf[8];
const bool isLittleEndian = Context.getAsmInfo()->isLittleEndian();
for (unsigned i = 0; i != Size; ++i) {
unsigned index = isLittleEndian ? i : (Size - i - 1);
buf[i] = uint8_t(Value >> (index * 8));
}
EmitBytes(StringRef(buf, Size));
}
/// EmitULEB128Value - Special case of EmitULEB128Value that avoids the
/// client having to pass in a MCExpr for constant integers.
void MCStreamer::EmitULEB128IntValue(uint64_t Value, unsigned Padding) {
SmallString<128> Tmp;
raw_svector_ostream OSE(Tmp);
encodeULEB128(Value, OSE, Padding);
EmitBytes(OSE.str());
}
/// EmitSLEB128Value - Special case of EmitSLEB128Value that avoids the
/// client having to pass in a MCExpr for constant integers.
void MCStreamer::EmitSLEB128IntValue(int64_t Value) {
SmallString<128> Tmp;
raw_svector_ostream OSE(Tmp);
encodeSLEB128(Value, OSE);
EmitBytes(OSE.str());
}
void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
const SMLoc &Loc) {
EmitValueImpl(Value, Size, Loc);
}
void MCStreamer::EmitSymbolValue(const MCSymbol *Sym, unsigned Size,
bool IsSectionRelative) {
assert((!IsSectionRelative || Size == 4) &&
"SectionRelative value requires 4-bytes");
if (!IsSectionRelative)
EmitValueImpl(MCSymbolRefExpr::Create(Sym, getContext()), Size);
else
EmitCOFFSecRel32(Sym);
}
void MCStreamer::EmitGPRel64Value(const MCExpr *Value) {
report_fatal_error("unsupported directive in streamer");
}
void MCStreamer::EmitGPRel32Value(const MCExpr *Value) {
report_fatal_error("unsupported directive in streamer");
}
/// EmitFill - Emit NumBytes bytes worth of the value specified by
/// FillValue. This implements directives such as '.space'.
void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
const MCExpr *E = MCConstantExpr::Create(FillValue, getContext());
for (uint64_t i = 0, e = NumBytes; i != e; ++i)
EmitValue(E, 1);
}
/// The implementation in this class just redirects to EmitFill.
void MCStreamer::EmitZeros(uint64_t NumBytes) {
EmitFill(NumBytes, 0);
}
unsigned MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
StringRef Directory,
StringRef Filename, unsigned CUID) {
return getContext().getDwarfFile(Directory, Filename, FileNo, CUID);
}
void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
unsigned Column, unsigned Flags,
unsigned Isa,
unsigned Discriminator,
StringRef FileName) {
getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
Discriminator);
}
MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
if (!Table.getLabel()) {
StringRef Prefix = Context.getAsmInfo()->getPrivateGlobalPrefix();
Table.setLabel(
Context.getOrCreateSymbol(Prefix + "line_table_start" + Twine(CUID)));
}
return Table.getLabel();
}
MCDwarfFrameInfo *MCStreamer::getCurrentDwarfFrameInfo() {
if (DwarfFrameInfos.empty())
return nullptr;
return &DwarfFrameInfos.back();
}
void MCStreamer::EnsureValidDwarfFrame() {
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
if (!CurFrame || CurFrame->End)
report_fatal_error("No open frame");
}
void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
MCSymbol *EHSymbol) {
}
void MCStreamer::InitSections(bool NoExecStack) {
SwitchSection(getContext().getObjectFileInfo()->getTextSection());
}
void MCStreamer::AssignSection(MCSymbol *Symbol, MCSection *Section) {
if (Section)
Symbol->setSection(*Section);
else
Symbol->setUndefined();
// As we emit symbols into a section, track the order so that they can
// be sorted upon later. Zero is reserved to mean 'unemitted'.
SymbolOrdering[Symbol] = 1 + SymbolOrdering.size();
}
void MCStreamer::EmitLabel(MCSymbol *Symbol) {
assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
assert(getCurrentSection().first && "Cannot emit before setting section!");
AssignSection(Symbol, getCurrentSection().first);
MCTargetStreamer *TS = getTargetStreamer();
if (TS)
TS->emitLabel(Symbol);
}
void MCStreamer::EmitCFISections(bool EH, bool Debug) {
assert(EH || Debug);
}
void MCStreamer::EmitCFIStartProc(bool IsSimple) {
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
if (CurFrame && !CurFrame->End)
report_fatal_error("Starting a frame before finishing the previous one!");
MCDwarfFrameInfo Frame;
Frame.IsSimple = IsSimple;
EmitCFIStartProcImpl(Frame);
const MCAsmInfo* MAI = Context.getAsmInfo();
if (MAI) {
for (const MCCFIInstruction& Inst : MAI->getInitialFrameState()) {
if (Inst.getOperation() == MCCFIInstruction::OpDefCfa ||
Inst.getOperation() == MCCFIInstruction::OpDefCfaRegister) {
Frame.CurrentCfaRegister = Inst.getRegister();
}
}
}
DwarfFrameInfos.push_back(Frame);
}
void MCStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
}
void MCStreamer::EmitCFIEndProc() {
EnsureValidDwarfFrame();
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
EmitCFIEndProcImpl(*CurFrame);
}
void MCStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
// Put a dummy non-null value in Frame.End to mark that this frame has been
// closed.
Frame.End = (MCSymbol *) 1;
}
MCSymbol *MCStreamer::EmitCFICommon() {
EnsureValidDwarfFrame();
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
return Label;
}
void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createDefCfa(Label, Register, Offset);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
}
void MCStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createDefCfaOffset(Label, Offset);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createAdjustCfaOffset(Label, Adjustment);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createDefCfaRegister(Label, Register);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
}
void MCStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createOffset(Label, Register, Offset);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createRelOffset(Label, Register, Offset);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIPersonality(const MCSymbol *Sym,
unsigned Encoding) {
EnsureValidDwarfFrame();
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Personality = Sym;
CurFrame->PersonalityEncoding = Encoding;
}
void MCStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
EnsureValidDwarfFrame();
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Lsda = Sym;
CurFrame->LsdaEncoding = Encoding;
}
void MCStreamer::EmitCFIRememberState() {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction = MCCFIInstruction::createRememberState(Label);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIRestoreState() {
// FIXME: Error if there is no matching cfi_remember_state.
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction = MCCFIInstruction::createRestoreState(Label);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFISameValue(int64_t Register) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createSameValue(Label, Register);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIRestore(int64_t Register) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createRestore(Label, Register);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIEscape(StringRef Values) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction = MCCFIInstruction::createEscape(Label, Values);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFISignalFrame() {
EnsureValidDwarfFrame();
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->IsSignalFrame = true;
}
void MCStreamer::EmitCFIUndefined(int64_t Register) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createUndefined(Label, Register);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createRegister(Label, Register1, Register2);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EmitCFIWindowSave() {
MCSymbol *Label = EmitCFICommon();
MCCFIInstruction Instruction =
MCCFIInstruction::createWindowSave(Label);
MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
CurFrame->Instructions.push_back(Instruction);
}
void MCStreamer::EnsureValidWinFrameInfo() {
const MCAsmInfo *MAI = Context.getAsmInfo();
if (!MAI->usesWindowsCFI())
report_fatal_error(".seh_* directives are not supported on this target");
if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End)
report_fatal_error("No open Win64 EH frame function!");
}
void MCStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
const MCAsmInfo *MAI = Context.getAsmInfo();
if (!MAI->usesWindowsCFI())
report_fatal_error(".seh_* directives are not supported on this target");
if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
report_fatal_error("Starting a function before ending the previous one!");
MCSymbol *StartProc = getContext().createTempSymbol();
EmitLabel(StartProc);
WinFrameInfos.push_back(new WinEH::FrameInfo(Symbol, StartProc));
CurrentWinFrameInfo = WinFrameInfos.back();
}
void MCStreamer::EmitWinCFIEndProc() {
EnsureValidWinFrameInfo();
if (CurrentWinFrameInfo->ChainedParent)
report_fatal_error("Not all chained regions terminated!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
CurrentWinFrameInfo->End = Label;
}
void MCStreamer::EmitWinCFIStartChained() {
EnsureValidWinFrameInfo();
MCSymbol *StartProc = getContext().createTempSymbol();
EmitLabel(StartProc);
WinFrameInfos.push_back(new WinEH::FrameInfo(CurrentWinFrameInfo->Function,
StartProc, CurrentWinFrameInfo));
CurrentWinFrameInfo = WinFrameInfos.back();
}
void MCStreamer::EmitWinCFIEndChained() {
EnsureValidWinFrameInfo();
if (!CurrentWinFrameInfo->ChainedParent)
report_fatal_error("End of a chained region outside a chained region!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
CurrentWinFrameInfo->End = Label;
CurrentWinFrameInfo =
const_cast<WinEH::FrameInfo *>(CurrentWinFrameInfo->ChainedParent);
}
void MCStreamer::EmitWinEHHandler(const MCSymbol *Sym, bool Unwind,
bool Except) {
EnsureValidWinFrameInfo();
if (CurrentWinFrameInfo->ChainedParent)
report_fatal_error("Chained unwind areas can't have handlers!");
CurrentWinFrameInfo->ExceptionHandler = Sym;
if (!Except && !Unwind)
report_fatal_error("Don't know what kind of handler this is!");
if (Unwind)
CurrentWinFrameInfo->HandlesUnwind = true;
if (Except)
CurrentWinFrameInfo->HandlesExceptions = true;
}
void MCStreamer::EmitWinEHHandlerData() {
EnsureValidWinFrameInfo();
if (CurrentWinFrameInfo->ChainedParent)
report_fatal_error("Chained unwind areas can't have handlers!");
}
void MCStreamer::EmitWinCFIPushReg(unsigned Register) {
EnsureValidWinFrameInfo();
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst = Win64EH::Instruction::PushNonVol(Label, Register);
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) {
EnsureValidWinFrameInfo();
if (CurrentWinFrameInfo->LastFrameInst >= 0)
report_fatal_error("Frame register and offset already specified!");
if (Offset & 0x0F)
report_fatal_error("Misaligned frame pointer offset!");
if (Offset > 240)
report_fatal_error("Frame offset must be less than or equal to 240!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst =
Win64EH::Instruction::SetFPReg(Label, Register, Offset);
CurrentWinFrameInfo->LastFrameInst = CurrentWinFrameInfo->Instructions.size();
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFIAllocStack(unsigned Size) {
EnsureValidWinFrameInfo();
if (Size == 0)
report_fatal_error("Allocation size must be non-zero!");
if (Size & 7)
report_fatal_error("Misaligned stack allocation!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst = Win64EH::Instruction::Alloc(Label, Size);
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFISaveReg(unsigned Register, unsigned Offset) {
EnsureValidWinFrameInfo();
if (Offset & 7)
report_fatal_error("Misaligned saved register offset!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst =
Win64EH::Instruction::SaveNonVol(Label, Register, Offset);
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFISaveXMM(unsigned Register, unsigned Offset) {
EnsureValidWinFrameInfo();
if (Offset & 0x0F)
report_fatal_error("Misaligned saved vector register offset!");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst =
Win64EH::Instruction::SaveXMM(Label, Register, Offset);
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFIPushFrame(bool Code) {
EnsureValidWinFrameInfo();
if (CurrentWinFrameInfo->Instructions.size() > 0)
report_fatal_error("If present, PushMachFrame must be the first UOP");
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
WinEH::Instruction Inst = Win64EH::Instruction::PushMachFrame(Label, Code);
CurrentWinFrameInfo->Instructions.push_back(Inst);
}
void MCStreamer::EmitWinCFIEndProlog() {
EnsureValidWinFrameInfo();
MCSymbol *Label = getContext().createTempSymbol();
EmitLabel(Label);
CurrentWinFrameInfo->PrologEnd = Label;
}
void MCStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
}
void MCStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol) {
}
/// EmitRawText - If this file is backed by an assembly streamer, this dumps
/// the specified string in the output .s file. This capability is
/// indicated by the hasRawTextSupport() predicate.
void MCStreamer::EmitRawTextImpl(StringRef String) {
errs() << "EmitRawText called on an MCStreamer that doesn't support it, "
" something must not be fully mc'ized\n";
abort();
}
void MCStreamer::EmitRawText(const Twine &T) {
SmallString<128> Str;
EmitRawTextImpl(T.toStringRef(Str));
}
void MCStreamer::EmitWindowsUnwindTables() {
}
void MCStreamer::Finish() {
if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
report_fatal_error("Unfinished frame!");
MCTargetStreamer *TS = getTargetStreamer();
if (TS)
TS->finish();
FinishImpl();
}
void MCStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
visitUsedExpr(*Value);
Symbol->setVariableValue(Value);
MCTargetStreamer *TS = getTargetStreamer();
if (TS)
TS->emitAssignment(Symbol, Value);
}
void MCStreamer::visitUsedSymbol(const MCSymbol &Sym) {
}
void MCStreamer::visitUsedExpr(const MCExpr &Expr) {
switch (Expr.getKind()) {
case MCExpr::Target:
cast<MCTargetExpr>(Expr).visitUsedExpr(*this);
break;
case MCExpr::Constant:
break;
case MCExpr::Binary: {
const MCBinaryExpr &BE = cast<MCBinaryExpr>(Expr);
visitUsedExpr(*BE.getLHS());
visitUsedExpr(*BE.getRHS());
break;
}
case MCExpr::SymbolRef:
visitUsedSymbol(cast<MCSymbolRefExpr>(Expr).getSymbol());
break;
case MCExpr::Unary:
visitUsedExpr(*cast<MCUnaryExpr>(Expr).getSubExpr());
break;
}
}
void MCStreamer::EmitInstruction(const MCInst &Inst,
const MCSubtargetInfo &STI) {
// Scan for values.
for (unsigned i = Inst.getNumOperands(); i--;)
if (Inst.getOperand(i).isExpr())
visitUsedExpr(*Inst.getOperand(i).getExpr());
}
void MCStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {}
void MCStreamer::EmitThumbFunc(MCSymbol *Func) {}
void MCStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
void MCStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {}
void MCStreamer::EndCOFFSymbolDef() {}
void MCStreamer::EmitFileDirective(StringRef Filename) {}
void MCStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {}
void MCStreamer::EmitCOFFSymbolType(int Type) {}
void MCStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
void MCStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
unsigned ByteAlignment) {}
void MCStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
uint64_t Size, unsigned ByteAlignment) {}
void MCStreamer::ChangeSection(MCSection *, const MCExpr *) {}
void MCStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
void MCStreamer::EmitBytes(StringRef Data) {}
void MCStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
const SMLoc &Loc) {
visitUsedExpr(*Value);
}
void MCStreamer::EmitULEB128Value(const MCExpr *Value) {}
void MCStreamer::EmitSLEB128Value(const MCExpr *Value) {}
void MCStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
unsigned ValueSize,
unsigned MaxBytesToEmit) {}
void MCStreamer::EmitCodeAlignment(unsigned ByteAlignment,
unsigned MaxBytesToEmit) {}
bool MCStreamer::EmitValueToOffset(const MCExpr *Offset, unsigned char Value) {
return false;
}
void MCStreamer::EmitBundleAlignMode(unsigned AlignPow2) {}
void MCStreamer::EmitBundleLock(bool AlignToEnd) {}
void MCStreamer::FinishImpl() {}
void MCStreamer::EmitBundleUnlock() {}
void MCStreamer::SwitchSection(MCSection *Section, const MCExpr *Subsection) {
assert(Section && "Cannot switch to a null section!");
MCSectionSubPair curSection = SectionStack.back().first;
SectionStack.back().second = curSection;
if (MCSectionSubPair(Section, Subsection) != curSection) {
ChangeSection(Section, Subsection);
SectionStack.back().first = MCSectionSubPair(Section, Subsection);
assert(!Section->hasEnded() && "Section already ended");
MCSymbol *Sym = Section->getBeginSymbol();
if (Sym && !Sym->isInSection())
EmitLabel(Sym);
}
}
MCSymbol *MCStreamer::endSection(MCSection *Section) {
// TODO: keep track of the last subsection so that this symbol appears in the
// correct place.
MCSymbol *Sym = Section->getEndSymbol(Context);
if (Sym->isInSection())
return Sym;
SwitchSection(Section);
EmitLabel(Sym);
return Sym;
}