From a88cb38d0220d5b0e4394f3280e1cec5f30ef4fc Mon Sep 17 00:00:00 2001
From: Stuart Hastings <stuart@apple.com>
Date: Wed, 31 Mar 2010 21:10:54 +0000
Subject: [PATCH] Debug info can now properly represent functions inside
 classes inside other functions.  Partial fix for Radar 7424645.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100048 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 33 +++++++++++++++++++++++----------
 lib/CodeGen/AsmPrinter/DwarfDebug.h   |  3 +++
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index d81c304356d..e3cf13a5d9a 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -780,12 +780,26 @@ void DwarfDebug::addToContextOwner(DIE *Die, DIDescriptor Context) {
   } else if (Context.isNameSpace()) {
     DIE *ContextDIE = getOrCreateNameSpace(DINameSpace(Context.getNode()));
     ContextDIE->addChild(Die);
+  } else if (Context.isSubprogram()) {
+    DIE *ContextDIE = createSubprogramDIE(DISubprogram(Context.getNode()),
+                                          /*MakeDecl=*/false);
+    ContextDIE->addChild(Die);
   } else if (DIE *ContextDIE = ModuleCU->getDIE(Context.getNode()))
     ContextDIE->addChild(Die);
   else 
     ModuleCU->addDie(Die);
 }
 
+/// isFunctionContext - True if given Context is nested within a function. 
+bool DwarfDebug::isFunctionContext(DIE *context) {
+  if (context == (DIE *)0)
+    return false;
+  if (context->getTag() == dwarf::DW_TAG_subprogram)
+    return true;
+  else
+    return isFunctionContext(context->getParent());
+}
+
 /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
 /// given DIType.
 DIE *DwarfDebug::getOrCreateTypeDIE(DIType Ty) {
@@ -967,6 +981,10 @@ void DwarfDebug::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
     if (DIDescriptor(ContainingType.getNode()).isCompositeType())
       addDIEEntry(&Buffer, dwarf::DW_AT_containing_type, dwarf::DW_FORM_ref4, 
                   getOrCreateTypeDIE(DIType(ContainingType.getNode())));
+    else {
+      DIDescriptor Context = CTy.getContext();
+      addToContextOwner(&Buffer, Context);
+    }
     break;
   }
   default:
@@ -1325,8 +1343,7 @@ DIE *DwarfDebug::updateSubprogramScopeDIE(MDNode *SPNode) {
  // function then gdb prefers the definition at top level and but does not
  // expect specification DIE in parent function. So avoid creating 
  // specification DIE for a function defined inside a function.
- if (SP.isDefinition() && !SP.getContext().isCompileUnit() &&
-     !SP.getContext().isFile() && !SP.getContext().isSubprogram()) {
+ if (SP.isDefinition() && !isFunctionContext(SPDie->getParent())) {
    addUInt(SPDie, dwarf::DW_AT_declaration, dwarf::DW_FORM_flag, 1);
    
    // Add arguments. 
@@ -1754,19 +1771,15 @@ void DwarfDebug::constructGlobalVariableDIE(MDNode *N) {
 void DwarfDebug::constructSubprogramDIE(MDNode *N) {
   DISubprogram SP(N);
 
-  // Check for pre-existence.
-  if (ModuleCU->getDIE(N))
-    return;
-
   if (!SP.isDefinition())
     // This is a method declaration which will be handled while constructing
     // class type.
     return;
 
-  DIE *SubprogramDie = createSubprogramDIE(SP);
-
-  // Add to map.
-  ModuleCU->insertDIE(N, SubprogramDie);
+  // Check for pre-existence.
+  DIE *SubprogramDie = ModuleCU->getDIE(N);
+  if (!SubprogramDie)
+    SubprogramDie = createSubprogramDIE(SP);
 
   // Add to context owner.
   addToContextOwner(SubprogramDie, SP.getContext());
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index ad6b0c2cb7c..fba39a14bbb 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -315,6 +315,9 @@ class DwarfDebug : public DwarfPrinter {
   /// addToContextOwner - Add Die into the list of its context owner's children.
   void addToContextOwner(DIE *Die, DIDescriptor Context);
 
+  /// isFunctionContext - True if given Context is nested within a function. 
+  bool isFunctionContext(DIE *context);
+
   /// addType - Add a new type attribute to the specified entity.
   void addType(DIE *Entity, DIType Ty);
 
-- 
2.11.0