fastisel doesn't need DwarfWriter, remove some tendricles.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100381 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 24 insertions, 11 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 539eba0133..3d86bf6fc9 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1793,24 +1793,39 @@ void DwarfDebug::constructSubprogramDIE(MDNode *N) {
 void DwarfDebug::beginModule(Module *M) {
   if (!Asm->MAI->doesSupportDebugInformation())
     return;
+  
+  MMI = Asm->MMI;
 
   TimeRegion Timer(DebugTimer);
-  
+
   DebugInfoFinder DbgFinder;
   DbgFinder.processModule(*M);
 
+  bool HasDebugInfo = false;
+  
+  // Scan all the compile-units to see if there are any marked as the main unit.
+  // if not, we do not generate debug info.
+  for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
+       E = DbgFinder.compile_unit_end(); I != E; ++I) {
+    if (DICompileUnit(*I).isMain()) {
+      HasDebugInfo = true;
+      break;
+    }
+  }
+  
+  if (!HasDebugInfo) return;
+
+  // Tell MMI that we have debug info.
+  MMI->setDebugInfoAvailability(true);
+  
   // Emit initial sections.
-  if (DbgFinder.compile_unit_begin() != DbgFinder.compile_unit_end())
-    EmitSectionLabels();
+  EmitSectionLabels();
   
   // Create all the compile unit DIEs.
   for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
          E = DbgFinder.compile_unit_end(); I != E; ++I)
     constructCompileUnit(*I);
 
-  if (!ModuleCU)
-    return;
-  
   // Create DIEs for each subprogram.
   for (DebugInfoFinder::iterator I = DbgFinder.subprogram_begin(),
          E = DbgFinder.subprogram_end(); I != E; ++I)
@@ -1821,10 +1836,6 @@ void DwarfDebug::beginModule(Module *M) {
          E = DbgFinder.global_variable_end(); I != E; ++I)
     constructGlobalVariableDIE(*I);
 
-  MMI = Asm->MMI;
-  shouldEmit = true;
-  MMI->setDebugInfoAvailability(true);
-
   // Prime section data.
   SectionMap.insert(Asm->getObjFileLowering().getTextSection());
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 320691b059..b38e485117 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -60,8 +60,10 @@ public:
 class DwarfDebug {
   /// Asm - Target of Dwarf emission.
   AsmPrinter *Asm;
+public:
   /// MMI - Collected machine module information.
   MachineModuleInfo *MMI;
+private:
 
   //===--------------------------------------------------------------------===//
   // Attributes used to construct specific Dwarf sections.
diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 1b019cd294..acc0066937 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -72,7 +72,7 @@ void DwarfWriter::EndFunction(const MachineFunction *MF) {
 /// ShouldEmitDwarfDebug - Returns true if Dwarf debugging declarations should
 /// be emitted.
 bool DwarfWriter::ShouldEmitDwarfDebug() const {
-  return DD && DD->ShouldEmitDwarfDebug();
+  return DD && DD->MMI->hasDebugInfo();
 }
 
 void DwarfWriter::BeginScope(const MachineInstr *MI) {