Close unique sections when switching away from them.

[oota-llvm.git] / lib / MC / MCStreamer.cpp

diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index ffbdc7111d5a452c7907fc086d95d970433f4496..3db2345540424791eeb09f95f83b8da1aed92194 100644 (file)
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -16,6 +16,7 @@
 #include "llvm/MC/MCExpr.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"
@@ -48,38 +49,16 @@ MCStreamer::~MCStreamer() {
 }
 
 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>());
 }
 
-const MCExpr *MCStreamer::BuildSymbolDiff(MCContext &Context,
-                                          const MCSymbol *A,
-                                          const MCSymbol *B) {
-  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 const MCExpr *forceExpAbs(MCStreamer &OS, const MCExpr* Expr) {
-  MCContext &Context = OS.getContext();
-  assert(!isa<MCSymbolRefExpr>(Expr));
-  if (Context.getAsmInfo()->hasAggressiveSymbolFolding())
-    return Expr;
-
-  MCSymbol *ABS = Context.CreateTempSymbol();
-  OS.EmitAssignment(ABS, Expr);
-  return MCSymbolRefExpr::Create(ABS, Context);
-}
-
 raw_ostream &MCStreamer::GetCommentOS() {
   // By default, discard comments.
   return nulls();
@@ -93,22 +72,10 @@ void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
         (MAB ? MAB->generateCompactUnwindEncoding(FI.Instructions) : 0);
 }
 
-void MCStreamer::EmitDwarfSetLineAddr(int64_t LineDelta,
-                                      const MCSymbol *Label, int PointerSize) {
-  // emit the sequence to set the address
-  EmitIntValue(dwarf::DW_LNS_extended_op, 1);
-  EmitULEB128IntValue(PointerSize + 1);
-  EmitIntValue(dwarf::DW_LNE_set_address, 1);
-  EmitSymbolValue(Label, PointerSize);
-
-  // emit the sequence for the LineDelta (from 1) and a zero address delta.
-  MCDwarfLineAddr::Emit(this, LineDelta, 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(Size <= 8 && "Invalid size");
+  assert(1 <= Size && Size <= 8 && "Invalid size");
   assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
          "Invalid size");
   char buf[8];
@@ -138,12 +105,6 @@ void MCStreamer::EmitSLEB128IntValue(int64_t Value) {
   EmitBytes(OSE.str());
 }
 
-void MCStreamer::EmitAbsValue(const MCExpr *Value, unsigned Size) {
-  const MCExpr *ABS = forceExpAbs(*this, Value);
-  EmitValue(ABS, Size);
-}
-
-
 void MCStreamer::EmitValue(const MCExpr *Value, unsigned Size,
                            const SMLoc &Loc) {
   EmitValueImpl(Value, Size, Loc);
@@ -222,7 +183,7 @@ void MCStreamer::EmitEHSymAttributes(const MCSymbol *Symbol,
                                      MCSymbol *EHSymbol) {
 }
 
-void MCStreamer::InitSections() {
+void MCStreamer::InitSections(bool NoExecStack) {
   SwitchSection(getContext().getObjectFileInfo()->getTextSection());
 }
 
@@ -247,12 +208,6 @@ void MCStreamer::EmitLabel(MCSymbol *Symbol) {
     TS->emitLabel(Symbol);
 }
 
-void MCStreamer::EmitCompactUnwindEncoding(uint32_t CompactUnwindEncoding) {
-  EnsureValidDwarfFrame();
-  MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
-  CurFrame->CompactUnwindEncoding = CompactUnwindEncoding;
-}
-
 void MCStreamer::EmitCFISections(bool EH, bool Debug) {
   assert(EH || Debug);
 }
@@ -266,6 +221,16 @@ void MCStreamer::EmitCFIStartProc(bool IsSimple) {
   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);
 }
 
@@ -297,6 +262,7 @@ void MCStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
     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) {
@@ -321,6 +287,7 @@ void MCStreamer::EmitCFIDefCfaRegister(int64_t Register) {
     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) {
@@ -695,3 +662,36 @@ void MCStreamer::EmitBundleAlignMode(unsigned AlignPow2) {}
 void MCStreamer::EmitBundleLock(bool AlignToEnd) {}
 void MCStreamer::FinishImpl() {}
 void MCStreamer::EmitBundleUnlock() {}
+
+void MCStreamer::SwitchSection(const 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) {
+    const MCSection *CurSec = curSection.first;
+    if (CurSec && CurSec->isUnique()) {
+      MCSymbol *Sym = curSection.first->getEndSymbol(Context);
+      if (!Sym->isInSection())
+        EmitLabel(Sym);
+    }
+    SectionStack.back().first = MCSectionSubPair(Section, Subsection);
+    assert(!Section->hasEnded() && "Section already ended");
+    ChangeSection(Section, Subsection);
+    MCSymbol *Sym = Section->getBeginSymbol();
+    if (Sym && !Sym->isInSection())
+      EmitLabel(Sym);
+  }
+}
+
+MCSymbol *MCStreamer::endSection(const 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;
+}