Reland 196270 "Generalize debug info / EH emission in AsmPrinter"

[oota-llvm.git] / lib / CodeGen / AsmPrinter / DwarfDebug.cpp

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index ec5df1ec4c7b0736fa6b795ac00e225baa23942b..010dcdf05556a9a687d99055dafefd2f8cfc86a9 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -197,6 +197,7 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   DwarfAddrSectionSym = 0;
   DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
   FunctionBeginSym = FunctionEndSym = 0;
+  CurFn = 0; CurMI = 0;
 
   // Turn on accelerator tables for Darwin by default, pubnames by
   // default for non-Darwin, and handle split dwarf.
@@ -1144,6 +1145,8 @@ void DwarfDebug::endSections() {
 
 // Emit all Dwarf sections that should come after the content.
 void DwarfDebug::endModule() {
+  assert(CurFn == 0);
+  assert(CurMI == 0);
 
   if (!FirstCU)
     return;
@@ -1225,8 +1228,7 @@ DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
 }
 
 // If Var is a current function argument then add it to CurrentFnArguments list.
-bool DwarfDebug::addCurrentFnArgument(const MachineFunction *MF,
-                                      DbgVariable *Var, LexicalScope *Scope) {
+bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
   if (!LScopes.isCurrentFunctionScope(Scope))
     return false;
   DIVariable DV = Var->getVariable();
@@ -1238,7 +1240,7 @@ bool DwarfDebug::addCurrentFnArgument(const MachineFunction *MF,
 
   size_t Size = CurrentFnArguments.size();
   if (Size == 0)
-    CurrentFnArguments.resize(MF->getFunction()->arg_size());
+    CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
   // llvm::Function argument size is not good indicator of how many
   // arguments does the function have at source level.
   if (ArgNo > Size)
@@ -1249,7 +1251,7 @@ bool DwarfDebug::addCurrentFnArgument(const MachineFunction *MF,
 
 // Collect variable information from side table maintained by MMI.
 void DwarfDebug::collectVariableInfoFromMMITable(
-    const MachineFunction *MF, SmallPtrSet<const MDNode *, 16> &Processed) {
+    SmallPtrSet<const MDNode *, 16> &Processed) {
   MachineModuleInfo::VariableDbgInfoMapTy &VMap = MMI->getVariableDbgInfo();
   for (MachineModuleInfo::VariableDbgInfoMapTy::iterator VI = VMap.begin(),
                                                          VE = VMap.end();
@@ -1270,7 +1272,7 @@ void DwarfDebug::collectVariableInfoFromMMITable(
     DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VP.second);
     DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
     RegVar->setFrameIndex(VP.first);
-    if (!addCurrentFnArgument(MF, RegVar, Scope))
+    if (!addCurrentFnArgument(RegVar, Scope))
       addScopeVariable(Scope, RegVar);
     if (AbsDbgVariable)
       AbsDbgVariable->setFrameIndex(VP.first);
@@ -1317,11 +1319,10 @@ static DotDebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
 
 // Find variables for each lexical scope.
 void
-DwarfDebug::collectVariableInfo(const MachineFunction *MF,
-                                SmallPtrSet<const MDNode *, 16> &Processed) {
+DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
 
   // Grab the variable info that was squirreled away in the MMI side-table.
-  collectVariableInfoFromMMITable(MF, Processed);
+  collectVariableInfoFromMMITable(Processed);
 
   for (SmallVectorImpl<const MDNode *>::const_iterator
            UVI = UserVariables.begin(),
@@ -1341,7 +1342,7 @@ DwarfDebug::collectVariableInfo(const MachineFunction *MF,
     DIVariable DV(Var);
     LexicalScope *Scope = NULL;
     if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
-        DISubprogram(DV.getContext()).describes(MF->getFunction()))
+        DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
       Scope = LScopes.getCurrentFunctionScope();
     else if (MDNode *IA = DV.getInlinedAt())
       Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
@@ -1355,7 +1356,7 @@ DwarfDebug::collectVariableInfo(const MachineFunction *MF,
     assert(MInsn->isDebugValue() && "History must begin with debug value");
     DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
     DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
-    if (!addCurrentFnArgument(MF, RegVar, Scope))
+    if (!addCurrentFnArgument(RegVar, Scope))
       addScopeVariable(Scope, RegVar);
     if (AbsVar)
       AbsVar->setMInsn(MInsn);
@@ -1437,6 +1438,8 @@ MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
 
 // Process beginning of an instruction.
 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
+  assert(CurMI == 0);
+  CurMI = MI;
   // Check if source location changes, but ignore DBG_VALUE locations.
   if (!MI->isDebugValue()) {
     DebugLoc DL = MI->getDebugLoc();
@@ -1478,14 +1481,16 @@ void DwarfDebug::beginInstruction(const MachineInstr *MI) {
 }
 
 // Process end of an instruction.
-void DwarfDebug::endInstruction(const MachineInstr *MI) {
+void DwarfDebug::endInstruction() {
+  assert(CurMI != 0);
   // Don't create a new label after DBG_VALUE instructions.
   // They don't generate code.
-  if (!MI->isDebugValue())
+  if (!CurMI->isDebugValue())
     PrevLabel = 0;
 
   DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
-      LabelsAfterInsn.find(MI);
+      LabelsAfterInsn.find(CurMI);
+  CurMI = 0;
 
   // No label needed.
   if (I == LabelsAfterInsn.end())
@@ -1565,6 +1570,7 @@ static DebugLoc getFnDebugLoc(DebugLoc DL, const LLVMContext &Ctx) {
 // Gather pre-function debug information.  Assumes being called immediately
 // after the function entry point has been emitted.
 void DwarfDebug::beginFunction(const MachineFunction *MF) {
+  CurFn = MF;
 
   // If there's no debug info for the function we're not going to do anything.
   if (!MMI->hasDebugInfo())
@@ -1792,8 +1798,19 @@ void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
 
 // Gather and emit post-function debug information.
 void DwarfDebug::endFunction(const MachineFunction *MF) {
-  if (!MMI->hasDebugInfo() || LScopes.empty())
+  // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
+  // though the beginFunction may not be called at all.
+  // We should handle both cases.
+  if (CurFn == 0)
+    CurFn = MF;
+  else
+    assert(CurFn == MF);
+  assert(CurFn != 0);
+
+  if (!MMI->hasDebugInfo() || LScopes.empty()) {
+    CurFn = 0;
     return;
+  }
 
   // Define end label for subprogram.
   FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
@@ -1803,7 +1820,7 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
   Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
 
   SmallPtrSet<const MDNode *, 16> ProcessedVars;
-  collectVariableInfo(MF, ProcessedVars);
+  collectVariableInfo(ProcessedVars);
 
   LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
   CompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
@@ -1837,7 +1854,7 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
 
   DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
 
-  if (!MF->getTarget().Options.DisableFramePointerElim(*MF))
+  if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
     TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
 
   // Clear debug info
@@ -1853,6 +1870,7 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
   LabelsBeforeInsn.clear();
   LabelsAfterInsn.clear();
   PrevLabel = NULL;
+  CurFn = 0;
 }
 
 // Register a source line with debug info. Returns the  unique label that was