4 files changed, 54 insertions, 37 deletions

diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 1d4f7f7ae6..7601199488 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -62,7 +62,7 @@ AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
     TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()),
     OutContext(Streamer.getContext()),
     OutStreamer(Streamer),
-    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0), PrevDLT(NULL) {
+    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
   DW = 0; MMI = 0;
   VerboseAsm = Streamer.isVerboseAsm();
 }
@@ -1337,25 +1337,12 @@ void AsmPrinter::processDebugLoc(const MachineInstr *MI,
   if (!MAI || !DW || !MAI->doesSupportDebugInformation()
       || !DW->ShouldEmitDwarfDebug())
     return;
-  if (MI->getOpcode() == TargetOpcode::DBG_VALUE)
-    return;
-  DebugLoc DL = MI->getDebugLoc();
-  if (DL.isUnknown())
-    return;
-  DILocation CurDLT = MF->getDILocation(DL);
-  if (!CurDLT.getScope().Verify())
-    return;
 
-  if (!BeforePrintingInsn) {
+  if (!BeforePrintingInsn)
     // After printing instruction
     DW->EndScope(MI);
-  } else if (CurDLT.getNode() != PrevDLT) {
-    MCSymbol *L = DW->RecordSourceLine(CurDLT.getLineNumber(), 
-                                       CurDLT.getColumnNumber(),
-                                       CurDLT.getScope().getNode());
-    DW->BeginScope(MI, L);
-    PrevDLT = CurDLT.getNode();
-  }
+  else
+    DW->BeginScope(MI);
 }
 
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index e2421eb070..1d00e0abcc 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -296,7 +296,7 @@ DwarfDebug::DwarfDebug(raw_ostream &OS, AsmPrinter *A, const MCAsmInfo *T)
   : DwarfPrinter(OS, A, T), ModuleCU(0),
     AbbreviationsSet(InitAbbreviationsSetSize), Abbreviations(),
     DIEValues(), SectionSourceLines(), didInitial(false), shouldEmit(false),
-    CurrentFnDbgScope(0), DebugTimer(0) {
+    CurrentFnDbgScope(0), PrevDILoc(0), DebugTimer(0) {
   NextStringPoolNumber = 0;
   if (TimePassesIsEnabled)
     DebugTimer = new Timer("Dwarf Debug Writer");
@@ -2036,19 +2036,58 @@ void DwarfDebug::collectVariableInfo() {
   }
 }
 
-/// beginScope - Process beginning of a scope starting at Label.
-void DwarfDebug::beginScope(const MachineInstr *MI, MCSymbol *Label) {
+/// beginScope - Process beginning of a scope.
+void DwarfDebug::beginScope(const MachineInstr *MI) {
+  // Ignore DBG_VALUE instructions.
+  if (MI->getOpcode() == TargetOpcode::DBG_VALUE)
+    return;
+
+  // Check location.
+  DebugLoc DL = MI->getDebugLoc();
+  if (DL.isUnknown())
+    return;
+  DILocation DILoc = MF->getDILocation(DL);
+  if (!DILoc.getScope().Verify())
+    return;
+
+  // Check and update last known location info.
+  if(DILoc.getNode() == PrevDILoc)
+    return;
+  PrevDILoc = DILoc.getNode();
+
+  // Emit a label to indicate location change. This is used for line 
+  // table even if this instruction does start a new scope.
+  MCSymbol *Label = recordSourceLine(DILoc.getLineNumber(),
+                                     DILoc.getColumnNumber(),
+                                     DILoc.getScope().getNode());
+
+  // update DbgScope if this instruction starts a new scope.
   InsnToDbgScopeMapTy::iterator I = DbgScopeBeginMap.find(MI);
   if (I == DbgScopeBeginMap.end())
     return;
+
   ScopeVector &SD = I->second;
   for (ScopeVector::iterator SDI = SD.begin(), SDE = SD.end();
        SDI != SDE; ++SDI)
     (*SDI)->setStartLabel(Label);
+
 }
 
 /// endScope - Process end of a scope.
 void DwarfDebug::endScope(const MachineInstr *MI) {
+  // Ignore DBG_VALUE instruction.
+  if (MI->getOpcode() == TargetOpcode::DBG_VALUE)
+    return;
+
+  // Check location.
+  DebugLoc DL = MI->getDebugLoc();
+  if (DL.isUnknown())
+    return;
+  DILocation DILoc = MF->getDILocation(DL);
+  if (!DILoc.getScope().Verify())
+    return;
+  
+  // Emit a label and update DbgScope if this instruction ends a scope.
   InsnToDbgScopeMapTy::iterator I = DbgScopeEndMap.find(MI);
   if (I == DbgScopeEndMap.end())
     return;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index d173f322b6..4a29091128 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -184,6 +184,10 @@ class DwarfDebug : public DwarfPrinter {
   /// function.
   DenseMap<CompileUnit *, unsigned> CompileUnitOffsets;
 
+  /// Previous instruction's location information. This is used to determine
+  /// label location to indicate scope boundries in dwarf debug info.
+  mutable const MDNode *PrevDILoc;
+
   /// DebugTimer - Timer for the Dwarf debug writer.
   Timer *DebugTimer;
   
@@ -542,8 +546,8 @@ public:
   /// collectVariableInfo - Populate DbgScope entries with variables' info.
   void collectVariableInfo();
 
-  /// beginScope - Process beginning of a scope starting at Label.
-  void beginScope(const MachineInstr *MI, MCSymbol *Label);
+  /// beginScope - Process beginning of a scope.
+  void beginScope(const MachineInstr *MI);
 
   /// endScope - Prcess end of a scope.
   void endScope(const MachineInstr *MI);
diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 9fd4c44785..a2d7ab1224 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -73,27 +73,14 @@ void DwarfWriter::EndFunction(const MachineFunction *MF) {
     MMI->EndFunction();
 }
 
-/// RecordSourceLine - Register a source line with debug info. Returns the
-/// unique label that was emitted and which provides correspondence to
-/// the source line list.
-MCSymbol *DwarfWriter::RecordSourceLine(unsigned Line, unsigned Col, 
-                                        MDNode *Scope) {
-  return DD->recordSourceLine(Line, Col, Scope);
-}
-
-/// getRecordSourceLineCount - Count source lines.
-unsigned DwarfWriter::getRecordSourceLineCount() {
-  return DD->getSourceLineCount();
-}
-
 /// ShouldEmitDwarfDebug - Returns true if Dwarf debugging declarations should
 /// be emitted.
 bool DwarfWriter::ShouldEmitDwarfDebug() const {
   return DD && DD->ShouldEmitDwarfDebug();
 }
 
-void DwarfWriter::BeginScope(const MachineInstr *MI, MCSymbol *L) {
-  DD->beginScope(MI, L);
+void DwarfWriter::BeginScope(const MachineInstr *MI) {
+  DD->beginScope(MI);
 }
 void DwarfWriter::EndScope(const MachineInstr *MI) {
   DD->endScope(MI);