Revise debug info machinery to digest nested functions and classes.

A certain GDB testsuite case (local.cc) has a function nested inside a
class nested inside another function.  GCC presents the innermost
function to llvm-convert first.  Heretofore, the debug info mistakenly
placed the inner function at module scope.  This patch walks the GCC
context links and instantiates the outer class and function so the
debug info is properly nested.  Radar 7426545.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100530 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 8 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index b472d1e533..0af6b3315a 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -800,12 +800,26 @@ 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) {
@@ -987,6 +1001,10 @@ 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:
@@ -1802,19 +1820,15 @@ 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());