X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FMCObjectStreamer.cpp;h=972610ac8d6eb018a64faea4db8bbe2dcf55909b;hb=HEAD;hp=f00231e3d316276ca4ac9ba87de4403aeca21e9c;hpb=89eb5dc65da7ce41d795277f8aa1503e6d82fe7b;p=oota-llvm.git

diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index f00231e3d31..972610ac8d6 100644
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -20,19 +20,16 @@
 #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_ostream &OS, MCCodeEmitter *Emitter_)
+                                   raw_pwrite_stream &OS,
+                                   MCCodeEmitter *Emitter_)
     : MCStreamer(Context),
       Assembler(new MCAssembler(Context, TAB, *Emitter_,
-                                *TAB.createObjectWriter(OS), OS)),
-      CurSectionData(0) {}
-
-MCObjectStreamer::MCObjectStreamer(MCContext &Context, MCAsmBackend &TAB,
-                                   raw_ostream &OS, MCCodeEmitter *Emitter_,
-                                   MCAssembler *_Assembler)
-    : MCStreamer(Context), Assembler(_Assembler), CurSectionData(0) {}
+                                *TAB.createObjectWriter(OS))),
+      EmitEHFrame(true), EmitDebugFrame(false) {}
 
 MCObjectStreamer::~MCObjectStreamer() {
   delete &Assembler->getBackend();
@@ -41,123 +38,151 @@ MCObjectStreamer::~MCObjectStreamer() {
   delete Assembler;
 }
 
+void MCObjectStreamer::flushPendingLabels(MCFragment *F, uint64_t FOffset) {
+  if (PendingLabels.empty())
+    return;
+  if (!F) {
+    F = new MCDataFragment();
+    MCSection *CurSection = getCurrentSectionOnly();
+    CurSection->getFragmentList().insert(CurInsertionPoint, F);
+    F->setParent(CurSection);
+  }
+  for (MCSymbol *Sym : PendingLabels) {
+    Sym->setFragment(F);
+    Sym->setOffset(FOffset);
+  }
+  PendingLabels.clear();
+}
+
+void MCObjectStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi,
+                                              const MCSymbol *Lo,
+                                              unsigned Size) {
+  // If not assigned to the same (valid) fragment, fallback.
+  if (!Hi->getFragment() || Hi->getFragment() != Lo->getFragment() ||
+      Hi->isVariable() || Lo->isVariable()) {
+    MCStreamer::emitAbsoluteSymbolDiff(Hi, Lo, Size);
+    return;
+  }
+
+  EmitIntValue(Hi->getOffset() - Lo->getOffset(), Size);
+}
+
 void MCObjectStreamer::reset() {
   if (Assembler)
     Assembler->reset();
-  CurSectionData = 0;
-  CurInsertionPoint = MCSectionData::iterator();
+  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!");
+  assert(getCurrentSectionOnly() && "No current section!");
 
-  if (CurInsertionPoint != getCurrentSectionData()->getFragmentList().begin())
-    return prior(CurInsertionPoint);
+  if (CurInsertionPoint != getCurrentSectionOnly()->getFragmentList().begin())
+    return &*std::prev(CurInsertionPoint);
 
-  return 0;
+  return nullptr;
 }
 
-MCDataFragment *MCObjectStreamer::getOrCreateDataFragment() const {
+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() && F->hasInstructions())) {
+  if (!F || (Assembler->isBundlingEnabled() && !Assembler->getRelaxAll() &&
+             F->hasInstructions())) {
     F = new MCDataFragment();
     insert(F);
   }
   return F;
 }
 
-const MCExpr *MCObjectStreamer::AddValueSymbols(const MCExpr *Value) {
-  switch (Value->getKind()) {
-  case MCExpr::Target:
-    cast<MCTargetExpr>(Value)->AddValueSymbols(Assembler);
-    break;
-
-  case MCExpr::Constant:
-    break;
-
-  case MCExpr::Binary: {
-    const MCBinaryExpr *BE = cast<MCBinaryExpr>(Value);
-    AddValueSymbols(BE->getLHS());
-    AddValueSymbols(BE->getRHS());
-    break;
-  }
-
-  case MCExpr::SymbolRef:
-    Assembler->getOrCreateSymbolData(cast<MCSymbolRefExpr>(Value)->getSymbol());
-    break;
-
-  case MCExpr::Unary:
-    AddValueSymbols(cast<MCUnaryExpr>(Value)->getSubExpr());
-    break;
-  }
+void MCObjectStreamer::visitUsedSymbol(const MCSymbol &Sym) {
+  Assembler->registerSymbol(Sym);
+}
 
-  return Value;
+void MCObjectStreamer::EmitCFISections(bool EH, bool Debug) {
+  MCStreamer::EmitCFISections(EH, Debug);
+  EmitEHFrame = EH;
+  EmitDebugFrame = Debug;
 }
 
-void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size) {
+void MCObjectStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
+                                     SMLoc Loc) {
+  MCStreamer::EmitValueImpl(Value, Size, Loc);
   MCDataFragment *DF = getOrCreateDataFragment();
+  flushPendingLabels(DF, DF->getContents().size());
 
   MCLineEntry::Make(this, getCurrentSection().first);
 
   // Avoid fixups when possible.
   int64_t AbsValue;
-  if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue, getAssembler())) {
+  if (Value->evaluateAsAbsolute(AbsValue, getAssembler())) {
     EmitIntValue(AbsValue, Size);
     return;
   }
   DF->getFixups().push_back(
-      MCFixup::Create(DF->getContents().size(), Value,
-                      MCFixup::getKindForSize(Size, false)));
+      MCFixup::create(DF->getContents().size(), Value,
+                      MCFixup::getKindForSize(Size, false), Loc));
   DF->getContents().resize(DF->getContents().size() + Size, 0);
 }
 
 void MCObjectStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
-  RecordProcStart(Frame);
+  // We need to create a local symbol to avoid relocations.
+  Frame.Begin = getContext().createTempSymbol();
+  EmitLabel(Frame.Begin);
 }
 
 void MCObjectStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
-  RecordProcEnd(Frame);
+  Frame.End = getContext().createTempSymbol();
+  EmitLabel(Frame.End);
 }
 
 void MCObjectStreamer::EmitLabel(MCSymbol *Symbol) {
   MCStreamer::EmitLabel(Symbol);
 
-  MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
-
-  // FIXME: This is wasteful, we don't necessarily need to create a data
-  // fragment. Instead, we should mark the symbol as pointing into the data
-  // fragment if it exists, otherwise we should just queue the label and set its
-  // fragment pointer when we emit the next fragment.
-  MCDataFragment *F = getOrCreateDataFragment();
-  assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
-  SD.setFragment(F);
-  SD.setOffset(F->getContents().size());
-}
-
-void MCObjectStreamer::EmitDebugLabel(MCSymbol *Symbol) {
-  EmitLabel(Symbol);
+  getAssembler().registerSymbol(*Symbol);
+
+  // 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())) {
+    Symbol->setFragment(F);
+    Symbol->setOffset(F->getContents().size());
+  } else {
+    PendingLabels.push_back(Symbol);
+  }
 }
 
 void MCObjectStreamer::EmitULEB128Value(const MCExpr *Value) {
   int64_t IntValue;
-  if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
+  if (Value->evaluateAsAbsolute(IntValue, getAssembler())) {
     EmitULEB128IntValue(IntValue);
     return;
   }
-  Value = ForceExpAbs(Value);
   insert(new MCLEBFragment(*Value, false));
 }
 
 void MCObjectStreamer::EmitSLEB128Value(const MCExpr *Value) {
   int64_t IntValue;
-  if (Value->EvaluateAsAbsolute(IntValue, getAssembler())) {
+  if (Value->evaluateAsAbsolute(IntValue, getAssembler())) {
     EmitSLEB128IntValue(IntValue);
     return;
   }
-  Value = ForceExpAbs(Value);
   insert(new MCLEBFragment(*Value, true));
 }
 
@@ -166,35 +191,44 @@ void MCObjectStreamer::EmitWeakReference(MCSymbol *Alias,
   report_fatal_error("This file format doesn't support weak aliases.");
 }
 
-void MCObjectStreamer::ChangeSection(const MCSection *Section,
+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);
 
-  CurSectionData = &getAssembler().getOrCreateSectionData(*Section);
+  bool Created = getAssembler().registerSection(*Section);
 
   int64_t IntSubsection = 0;
   if (Subsection &&
-      !Subsection->EvaluateAsAbsolute(IntSubsection, getAssembler()))
+      !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));
+      Section->getSubsectionInsertionPoint(unsigned(IntSubsection));
+  return Created;
 }
 
 void MCObjectStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
-  getAssembler().getOrCreateSymbolData(*Symbol);
-  Symbol->setVariableValue(AddValueSymbols(Value));
+  getAssembler().registerSymbol(*Symbol);
+  MCStreamer::EmitAssignment(Symbol, Value);
+}
+
+bool MCObjectStreamer::mayHaveInstructions(MCSection &Sec) const {
+  return Sec.hasInstructions();
 }
 
-void MCObjectStreamer::EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) {
-  // Scan for values.
-  for (unsigned i = Inst.getNumOperands(); i--; )
-    if (Inst.getOperand(i).isExpr())
-      AddValueSymbols(Inst.getOperand(i).getExpr());
+void MCObjectStreamer::EmitInstruction(const MCInst &Inst,
+                                       const MCSubtargetInfo &STI) {
+  MCStreamer::EmitInstruction(Inst, STI);
 
-  MCSectionData *SD = getCurrentSectionData();
-  SD->setHasInstructions(true);
+  MCSection *Sec = getCurrentSectionOnly();
+  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.
@@ -213,7 +247,7 @@ void MCObjectStreamer::EmitInstruction(const MCInst &Inst, const MCSubtargetInfo
   //   group. We want to emit all such instructions into the same data
   //   fragment.
   if (Assembler.getRelaxAll() ||
-      (Assembler.isBundlingEnabled() && SD->isBundleLocked())) {
+      (Assembler.isBundlingEnabled() && Sec->isBundleLocked())) {
     MCInst Relaxed;
     getAssembler().getBackend().relaxInstruction(Inst, Relaxed);
     while (getAssembler().getBackend().mayNeedRelaxation(Relaxed))
@@ -228,6 +262,9 @@ void MCObjectStreamer::EmitInstruction(const MCInst &Inst, const MCSubtargetInfo
 
 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);
@@ -235,9 +272,8 @@ void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst,
 
   SmallString<128> Code;
   raw_svector_ostream VecOS(Code);
-  getAssembler().getEmitter().EncodeInstruction(Inst, VecOS, IF->getFixups(),
+  getAssembler().getEmitter().encodeInstruction(Inst, VecOS, IF->getFixups(),
                                                 STI);
-  VecOS.flush();
   IF->getContents().append(Code.begin(), Code.end());
 }
 
@@ -271,39 +307,66 @@ void MCObjectStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
                                           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,
+                                 MCDwarfLineTableParams Params,
+                                 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, Params, LineDelta, 0);
+}
+
 void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
                                                 const MCSymbol *LastLabel,
                                                 const MCSymbol *Label,
                                                 unsigned PointerSize) {
   if (!LastLabel) {
-    EmitDwarfSetLineAddr(LineDelta, Label, PointerSize);
+    emitDwarfSetLineAddr(*this, Assembler->getDWARFLinetableParams(), LineDelta,
+                         Label, PointerSize);
     return;
   }
-  const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel);
+  const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
   int64_t Res;
-  if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
-    MCDwarfLineAddr::Emit(this, LineDelta, Res);
+  if (AddrDelta->evaluateAsAbsolute(Res, getAssembler())) {
+    MCDwarfLineAddr::Emit(this, Assembler->getDWARFLinetableParams(), LineDelta,
+                          Res);
     return;
   }
-  AddrDelta = ForceExpAbs(AddrDelta);
   insert(new MCDwarfLineAddrFragment(LineDelta, *AddrDelta));
 }
 
 void MCObjectStreamer::EmitDwarfAdvanceFrameAddr(const MCSymbol *LastLabel,
                                                  const MCSymbol *Label) {
-  const MCExpr *AddrDelta = BuildSymbolDiff(getContext(), Label, LastLabel);
+  const MCExpr *AddrDelta = buildSymbolDiff(*this, Label, LastLabel);
   int64_t Res;
-  if (AddrDelta->EvaluateAsAbsolute(Res, getAssembler())) {
+  if (AddrDelta->evaluateAsAbsolute(Res, getAssembler())) {
     MCDwarfFrameEmitter::EmitAdvanceLoc(*this, Res);
     return;
   }
-  AddrDelta = ForceExpAbs(AddrDelta);
   insert(new MCDwarfCallFrameFragment(*AddrDelta));
 }
 
 void MCObjectStreamer::EmitBytes(StringRef Data) {
   MCLineEntry::Make(this, getCurrentSection().first);
-  getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
+  MCDataFragment *DF = getOrCreateDataFragment();
+  flushPendingLabels(DF, DF->getContents().size());
+  DF->getContents().append(Data.begin(), Data.end());
 }
 
 void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
@@ -315,8 +378,9 @@ void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
   insert(new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit));
 
   // Update the maximum alignment on the current section if necessary.
-  if (ByteAlignment > getCurrentSectionData()->getAlignment())
-    getCurrentSectionData()->setAlignment(ByteAlignment);
+  MCSection *CurSec = getCurrentSection().first;
+  if (ByteAlignment > CurSec->getAlignment())
+    CurSec->setAlignment(ByteAlignment);
 }
 
 void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment,
@@ -325,33 +389,17 @@ void MCObjectStreamer::EmitCodeAlignment(unsigned ByteAlignment,
   cast<MCAlignFragment>(getCurrentFragment())->setEmitNops(true);
 }
 
-bool MCObjectStreamer::EmitValueToOffset(const MCExpr *Offset,
+void 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;
+  insert(new MCOrgFragment(*Offset, Value));
 }
 
 // Associate GPRel32 fixup with data and resize data area
 void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
+  flushPendingLabels(DF, DF->getContents().size());
 
-  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), 
+  DF->getFixups().push_back(MCFixup::create(DF->getContents().size(), 
                                             Value, FK_GPRel_4));
   DF->getContents().resize(DF->getContents().size() + 4, 0);
 }
@@ -359,32 +407,48 @@ void MCObjectStreamer::EmitGPRel32Value(const MCExpr *Value) {
 // Associate GPRel32 fixup with data and resize data area
 void MCObjectStreamer::EmitGPRel64Value(const MCExpr *Value) {
   MCDataFragment *DF = getOrCreateDataFragment();
+  flushPendingLabels(DF, DF->getContents().size());
 
-  DF->getFixups().push_back(MCFixup::Create(DF->getContents().size(), 
+  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);
+bool MCObjectStreamer::EmitRelocDirective(const MCExpr &Offset, StringRef Name,
+                                          const MCExpr *Expr, SMLoc Loc) {
+  int64_t OffsetValue;
+  if (!Offset.evaluateAsAbsolute(OffsetValue))
+    llvm_unreachable("Offset is not absolute");
+
+  MCDataFragment *DF = getOrCreateDataFragment();
+  flushPendingLabels(DF, DF->getContents().size());
+
+  MCFixupKind Kind;
+  if (!Assembler->getBackend().getFixupKind(Name, Kind))
+    return true;
+
+  if (Expr == nullptr)
+    Expr =
+        MCSymbolRefExpr::create(getContext().createTempSymbol(), getContext());
+  DF->getFixups().push_back(MCFixup::create(OffsetValue, Expr, Kind, Loc));
+  return false;
 }
 
-void MCObjectStreamer::EmitZeros(uint64_t NumBytes) {
-  unsigned ItemSize = getCurrentSection().first->isVirtualSection() ? 0 : 1;
-  insert(new MCFillFragment(0, ItemSize, NumBytes));
+void MCObjectStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue) {
+  const MCSection *Sec = getCurrentSection().first;
+  assert(Sec && "need a section");
+  unsigned ItemSize = Sec->isVirtualSection() ? 0 : 1;
+  insert(new MCFillFragment(FillValue, ItemSize, NumBytes));
 }
 
 void MCObjectStreamer::FinishImpl() {
-  // Dump out the dwarf file & directory tables and line tables.
-  const MCSymbol *LineSectionSymbol = NULL;
-  if (getContext().hasDwarfFiles())
-    LineSectionSymbol = MCDwarfFileTable::Emit(this);
-
   // If we are generating dwarf for assembly source files dump out the sections.
   if (getContext().getGenDwarfForAssembly())
-    MCGenDwarfInfo::Emit(this, LineSectionSymbol);
+    MCGenDwarfInfo::Emit(this);
+
+  // Dump out the dwarf file & directory tables and line tables.
+  MCDwarfLineTable::Emit(this, getAssembler().getDWARFLinetableParams());
 
+  flushPendingLabels(nullptr);
   getAssembler().Finish();
 }