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-rw-r--r--contrib/llvm/lib/MC/MCObjectStreamer.cpp461
1 files changed, 461 insertions, 0 deletions
diff --git a/contrib/llvm/lib/MC/MCObjectStreamer.cpp b/contrib/llvm/lib/MC/MCObjectStreamer.cpp
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+++ b/contrib/llvm/lib/MC/MCObjectStreamer.cpp
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+//===- lib/MC/MCObjectStreamer.cpp - Object File MCStreamer Interface -----===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/MC/MCObjectStreamer.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/MC/MCAsmBackend.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCCodeEmitter.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDwarf.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSection.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
+using namespace llvm;
+
+MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
+ raw_pwrite_stream &OS,
+ MCCodeEmitter *Emitter_)
+ : MCStreamer(Context),
+ Assembler(new MCAssembler(Context, TAB, *Emitter_,
+ *TAB.createObjectWriter(OS), OS)),
+ CurSectionData(nullptr), EmitEHFrame(true), EmitDebugFrame(false) {}
+
+MCObjectStreamer::~MCObjectStreamer() {
+ delete &Assembler->getBackend();
+ delete &Assembler->getEmitter();
+ delete &Assembler->getWriter();
+ delete Assembler;
+}
+
+void MCObjectStreamer::flushPendingLabels(MCFragment *F, uint64_t FOffset) {
+ if (PendingLabels.size()) {
+ if (!F) {
+ F = new MCDataFragment();
+ CurSectionData->getFragmentList().insert(CurInsertionPoint, F);
+ F->setParent(CurSectionData);
+ }
+ for (MCSymbolData *SD : PendingLabels) {
+ SD->setFragment(F);
+ SD->setOffset(FOffset);
+ }
+ PendingLabels.clear();
+ }
+}
+
+bool MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
+ const MCSymbol *Lo,
+ unsigned Size) {
+ // Must have symbol data.
+ if (!Assembler->hasSymbolData(*Hi) || !Assembler->hasSymbolData(*Lo))
+ return false;
+ auto &HiD = Assembler->getSymbolData(*Hi);
+ auto &LoD = Assembler->getSymbolData(*Lo);
+
+ // Must both be assigned to the same (valid) fragment.
+ if (!HiD.getFragment() || HiD.getFragment() != LoD.getFragment())
+ return false;
+
+ // Must be a data fragment.
+ if (!isa<MCDataFragment>(HiD.getFragment()))
+ return false;
+
+ assert(HiD.getOffset() >= LoD.getOffset() &&
+ "Expected Hi to be greater than Lo");
+ EmitIntValue(HiD.getOffset() - LoD.getOffset(), Size);
+ return true;
+}
+
+void MCObjectStreamer::reset() {
+ if (Assembler)
+ Assembler->reset();
+ CurSectionData = nullptr;
+ CurInsertionPoint = MCSection::iterator();
+ EmitEHFrame = true;
+ EmitDebugFrame = false;
+ PendingLabels.clear();
+ MCStreamer::reset();
+}
+
+void MCObjectStreamer::EmitFrames(MCAsmBackend *MAB) {
+ if (!getNumFrameInfos())
+ return;
+
+ if (EmitEHFrame)
+ MCDwarfFrameEmitter::Emit(*this, MAB, true);
+
+ if (EmitDebugFrame)
+ MCDwarfFrameEmitter::Emit(*this, MAB, false);
+}
+
+MCFragment *MCObjectStreamer::getCurrentFragment() const {
+ assert(getCurrentSectionData() && "No current section!");
+
+ if (CurInsertionPoint != getCurrentSectionData()->getFragmentList().begin())
+ return std::prev(CurInsertionPoint);
+
+ return nullptr;
+}
+
+MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() {
+ MCDataFragment *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ // When bundling is enabled, we don't want to add data to a fragment that
+ // already has instructions (see MCELFStreamer::EmitInstToData for details)
+ if (!F || (Assembler->isBundlingEnabled() && !Assembler->getRelaxAll() &&
+ F->hasInstructions())) {
+ F = new MCDataFragment();
+ insert(F);
+ }
+ return F;
+}
+
+void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) {
+ Assembler->getOrCreateSymbolData(Sym);
+}
+
+void MCObjectStreamer::EmitCFISections(bool EH, bool Debug) {
+ MCStreamer::EmitCFISections(EH, Debug);
+ EmitEHFrame = EH;
+ EmitDebugFrame = Debug;
+}
+
+void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+ const SMLoc &Loc) {
+ MCStreamer::EmitValueImpl(Value, Size, Loc);
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ MCLineEntry::Make(this, getCurrentSection().first);
+
+ // Avoid fixups when possible.
+ int64_t AbsValue;
+ if (Value->EvaluateAsAbsolute(AbsValue, getAssembler())) {
+ EmitIntValue(AbsValue, Size);
+ return;
+ }
+ DF->getFixups().push_back(
+ MCFixup::create(DF->getContents().size(), Value,
+ MCFixup::getKindForSize(Size, false), Loc));
+ DF->getContents().resize(DF->getContents().size() + Size, 0);
+}
+
+void MCObjectStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
+ // We need to create a local symbol to avoid relocations.
+ Frame.Begin = getContext().createTempSymbol();
+ EmitLabel(Frame.Begin);
+}
+
+void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
+ Frame.End = getContext().createTempSymbol();
+ EmitLabel(Frame.End);
+}
+
+void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
+ MCStreamer::EmitLabel(Symbol);
+
+ MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
+ assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
+
+ // If there is a current fragment, mark the symbol as pointing into it.
+ // Otherwise queue the label and set its fragment pointer when we emit the
+ // next fragment.
+ auto *F = dyn_cast_or_null<MCDataFragment>(getCurrentFragment());
+ if (F && !(getAssembler().isBundlingEnabled() &&
+ getAssembler().getRelaxAll())) {
+ SD.setFragment(F);
+ SD.setOffset(F->getContents().size());
+ } else {
+ PendingLabels.push_back(&SD);
+ }
+}
+
+void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) {
+ int64_t IntValue;
+ if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
+ EmitULEB128IntValue(IntValue);
+ return;
+ }
+ insert(new MCLEBFragment(*Value, false));
+}
+
+void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) {
+ int64_t IntValue;
+ if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
+ EmitSLEB128IntValue(IntValue);
+ return;
+ }
+ insert(new MCLEBFragment(*Value, true));
+}
+
+void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias,
+ const MCSymbol *Symbol) {
+ report_fatal_error("This file format doesn't support weak aliases.");
+}
+
+void MCObjectStreamer::ChangeSection(MCSection *Section,
+ const MCExpr *Subsection) {
+ changeSectionImpl(Section, Subsection);
+}
+
+bool MCObjectStreamer::changeSectionImpl(MCSection *Section,
+ const MCExpr *Subsection) {
+ assert(Section && "Cannot switch to a null section!");
+ flushPendingLabels(nullptr);
+
+ bool Created = getAssembler().registerSection(*Section);
+ CurSectionData = Section;
+
+ int64_t IntSubsection = 0;
+ if (Subsection &&
+ !Subsection->EvaluateAsAbsolute(IntSubsection, getAssembler()))
+ report_fatal_error("Cannot evaluate subsection number");
+ if (IntSubsection < 0 || IntSubsection > 8192)
+ report_fatal_error("Subsection number out of range");
+ CurInsertionPoint =
+ CurSectionData->getSubsectionInsertionPoint(unsigned(IntSubsection));
+ return Created;
+}
+
+void MCObjectStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
+ getAssembler().getOrCreateSymbolData(*Symbol);
+ MCStreamer::EmitAssignment(Symbol, Value);
+}
+
+bool MCObjectStreamer::mayHaveInstructions(MCSection &Sec) const {
+ return Sec.hasInstructions();
+}
+
+void MCObjectStreamer::EmitInstruction(const MCInst &Inst,
+ const MCSubtargetInfo &STI) {
+ MCStreamer::EmitInstruction(Inst, STI);
+
+ MCSection *Sec = getCurrentSectionData();
+ Sec->setHasInstructions(true);
+
+ // Now that a machine instruction has been assembled into this section, make
+ // a line entry for any .loc directive that has been seen.
+ MCLineEntry::Make(this, getCurrentSection().first);
+
+ // If this instruction doesn't need relaxation, just emit it as data.
+ MCAssembler &Assembler = getAssembler();
+ if (!Assembler.getBackend().mayNeedRelaxation(Inst)) {
+ EmitInstToData(Inst, STI);
+ return;
+ }
+
+ // Otherwise, relax and emit it as data if either:
+ // - The RelaxAll flag was passed
+ // - Bundling is enabled and this instruction is inside a bundle-locked
+ // group. We want to emit all such instructions into the same data
+ // fragment.
+ if (Assembler.getRelaxAll() ||
+ (Assembler.isBundlingEnabled() && Sec->isBundleLocked())) {
+ MCInst Relaxed;
+ getAssembler().getBackend().relaxInstruction(Inst, Relaxed);
+ while (getAssembler().getBackend().mayNeedRelaxation(Relaxed))
+ getAssembler().getBackend().relaxInstruction(Relaxed, Relaxed);
+ EmitInstToData(Relaxed, STI);
+ return;
+ }
+
+ // Otherwise emit to a separate fragment.
+ EmitInstToFragment(Inst, STI);
+}
+
+void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst,
+ const MCSubtargetInfo &STI) {
+ if (getAssembler().getRelaxAll() && getAssembler().isBundlingEnabled())
+ llvm_unreachable("All instructions should have already been relaxed");
+
+ // Always create a new, separate fragment here, because its size can change
+ // during relaxation.
+ MCRelaxableFragment *IF = new MCRelaxableFragment(Inst, STI);
+ insert(IF);
+
+ SmallString<128> Code;
+ raw_svector_ostream VecOS(Code);
+ getAssembler().getEmitter().encodeInstruction(Inst, VecOS, IF->getFixups(),
+ STI);
+ VecOS.flush();
+ IF->getContents().append(Code.begin(), Code.end());
+}
+
+#ifndef NDEBUG
+static const char *const BundlingNotImplementedMsg =
+ "Aligned bundling is not implemented for this object format";
+#endif
+
+void MCObjectStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleLock(bool AlignToEnd) {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleUnlock() {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
+ unsigned Column, unsigned Flags,
+ unsigned Isa,
+ unsigned Discriminator,
+ StringRef FileName) {
+ // In case we see two .loc directives in a row, make sure the
+ // first one gets a line entry.
+ MCLineEntry::Make(this, getCurrentSection().first);
+
+ this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
+ Isa, Discriminator, FileName);
+}
+
+static const MCExpr *buildSymbolDiff(MCObjectStreamer &OS, const MCSymbol *A,
+ const MCSymbol *B) {
+ MCContext &Context = OS.getContext();
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+ const MCExpr *ARef = MCSymbolRefExpr::Create(A, Variant, Context);
+ const MCExpr *BRef = MCSymbolRefExpr::Create(B, Variant, Context);
+ const MCExpr *AddrDelta =
+ MCBinaryExpr::Create(MCBinaryExpr::Sub, ARef, BRef, Context);
+ return AddrDelta;
+}
+
+static void emitDwarfSetLineAddr(MCObjectStreamer &OS, int64_t LineDelta,
+ const MCSymbol *Label, int PointerSize) {
+ // emit the sequence to set the address
+ OS.EmitIntValue(dwarf::DW_LNS_extended_op, 1);
+ OS.EmitULEB128IntValue(PointerSize + 1);
+ OS.EmitIntValue(dwarf::DW_LNE_set_address, 1);
+ OS.EmitSymbolValue(Label, PointerSize);
+
+ // emit the sequence for the LineDelta (from 1) and a zero address delta.
+ MCDwarfLineAddr::Emit(&OS, LineDelta, 0);
+}
+
+void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
+ const MCSymbol *LastLabel,
+ const MCSymbol *Label,
+ unsigned PointerSize) {
+ if (!LastLabel) {
+ emitDwarfSetLineAddr(*this, LineDelta, Label, PointerSize);
+ return;
+ }
+ const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
+ int64_t Res;
+ if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
+ MCDwarfLineAddr::Emit(this, LineDelta, Res);
+ return;
+ }
+ insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta));
+}
+
+void MCObjectStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
+ const MCSymbol *Label) {
+ const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
+ int64_t Res;
+ if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
+ MCDwarfFrameEmitter::EmitAdvanceLoc(*this, Res);
+ return;
+ }
+ insert(new MCDwarfCallFrameFragment(*AddrDelta));
+}
+
+void MCObjectStreamer::EmitBytes(StringRef Data) {
+ MCLineEntry::Make(this, getCurrentSection().first);
+ getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
+}
+
+void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
+ int64_t Value,
+ unsigned ValueSize,
+ unsigned MaxBytesToEmit) {
+ if (MaxBytesToEmit == 0)
+ MaxBytesToEmit = ByteAlignment;
+ insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
+
+ // Update the maximum alignment on the current section if necessary.
+ MCSection *CurSec = getCurrentSection().first;
+ if (ByteAlignment > CurSec->getAlignment())
+ CurSec->setAlignment(ByteAlignment);
+}
+
+void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment,
+ unsigned MaxBytesToEmit) {
+ EmitValueToAlignment(ByteAlignment, 0, 1, MaxBytesToEmit);
+ cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true);
+}
+
+bool MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset,
+ unsigned char Value) {
+ int64_t Res;
+ if (Offset->EvaluateAsAbsolute(Res, getAssembler())) {
+ insert(new MCOrgFragment(*Offset, Value));
+ return false;
+ }
+
+ MCSymbol *CurrentPos = getContext().createTempSymbol();
+ EmitLabel(CurrentPos);
+ MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
+ const MCExpr *Ref =
+ MCSymbolRefExpr::Create(CurrentPos, Variant, getContext());
+ const MCExpr *Delta =
+ MCBinaryExpr::Create(MCBinaryExpr::Sub, Offset, Ref, getContext());
+
+ if (!Delta->EvaluateAsAbsolute(Res, getAssembler()))
+ return true;
+ EmitFill(Res, Value);
+ return false;
+}
+
+// Associate GPRel32 fixup with data and resize data area
+void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
+ Value, FK_GPRel_4));
+ DF->getContents().resize(DF->getContents().size() + 4, 0);
+}
+
+// Associate GPRel32 fixup with data and resize data area
+void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) {
+ MCDataFragment *DF = getOrCreateDataFragment();
+
+ DF->getFixups().push_back(MCFixup::create(DF->getContents().size(),
+ Value, FK_GPRel_4));
+ DF->getContents().resize(DF->getContents().size() + 8, 0);
+}
+
+void MCObjectStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
+ // FIXME: A MCFillFragment would be more memory efficient but MCExpr has
+ // problems evaluating expressions across multiple fragments.
+ getOrCreateDataFragment()->getContents().append(NumBytes, FillValue);
+}
+
+void MCObjectStreamer::EmitZeros(uint64_t NumBytes) {
+ const MCSection *Sec = getCurrentSection().first;
+ assert(Sec && "need a section");
+ unsigned ItemSize = Sec->isVirtualSection() ? 0 : 1;
+ insert(new MCFillFragment(0, ItemSize, NumBytes));
+}
+
+void MCObjectStreamer::FinishImpl() {
+ // If we are generating dwarf for assembly source files dump out the sections.
+ if (getContext().getGenDwarfForAssembly())
+ MCGenDwarfInfo::Emit(this);
+
+ // Dump out the dwarf file & directory tables and line tables.
+ MCDwarfLineTable::Emit(this);
+
+ flushPendingLabels(nullptr);
+ getAssembler().Finish();
+}
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