diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 049294e..7915c37 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -1650,6 +1650,8 @@
                                           SC_None,
                                           false, false);
 
+  // Initialize debug info if necessary.
+  CGF.maybeInitializeDebugInfo();
   CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation());
 
   if (byrefInfo.needsCopy()) {
@@ -1720,6 +1722,8 @@
                                           SC_Static,
                                           SC_None,
                                           false, false);
+  // Initialize debug info if necessary.
+  CGF.maybeInitializeDebugInfo();
   CGF.StartFunction(FD, R, Fn, FI, args, SourceLocation());
 
   if (byrefInfo.needsDispose()) {
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 5291fc8..730f866 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -2050,14 +2050,22 @@
   FnBeginRegionCount.push_back(LexicalBlockStack.size());
 
   const Decl *D = GD.getDecl();
+  // Function may lack declaration in source code if it is created by Clang
+  // CodeGen (examples: _GLOBAL__I_a, __cxx_global_array_dtor, thunk).
+  bool HasDecl = (D != 0);
   // Use the location of the declaration.
-  SourceLocation Loc = D->getLocation();
-  
+  SourceLocation Loc;
+  if (HasDecl)
+    Loc = D->getLocation();
+
   unsigned Flags = 0;
   llvm::DIFile Unit = getOrCreateFile(Loc);
   llvm::DIDescriptor FDContext(Unit);
   llvm::DIArray TParamsArray;
-  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+  if (!HasDecl) {
+    // Use llvm function name.
+    Name = Fn->getName();
+  } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
     // If there is a DISubprogram for this function available then use it.
     llvm::DenseMap<const FunctionDecl *, llvm::WeakVH>::iterator
       FI = SPCache.find(FD->getCanonicalDecl());
@@ -2104,12 +2112,13 @@
     Name = Name.substr(1);
 
   unsigned LineNo = getLineNumber(Loc);
-  if (D->isImplicit())
+  if (!HasDecl || D->isImplicit())
     Flags |= llvm::DIDescriptor::FlagArtificial;
 
   llvm::DIType DIFnType;
   llvm::DISubprogram SPDecl;
-  if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
+  if (HasDecl &&
+      CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
     DIFnType = getOrCreateFunctionType(D, FnType, Unit);
     SPDecl = getFunctionDeclaration(D);
   } else {
@@ -2132,7 +2141,8 @@
   // Push function on region stack.
   llvm::MDNode *SPN = SP;
   LexicalBlockStack.push_back(SPN);
-  RegionMap[D] = llvm::WeakVH(SP);
+  if (HasDecl)
+    RegionMap[D] = llvm::WeakVH(SP);
 }
 
 /// EmitLocation - Emit metadata to indicate a change in line/column
diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp
index 9f7ee1e..67f710d 100644
--- a/lib/CodeGen/CGDeclCXX.cpp
+++ b/lib/CodeGen/CGDeclCXX.cpp
@@ -163,6 +163,9 @@
 
   CodeGenFunction CGF(CGM);
 
+  // Initialize debug info if needed.
+  CGF.maybeInitializeDebugInfo();
+
   CGF.StartFunction(GlobalDecl(), CGM.getContext().VoidTy, fn,
                     CGM.getTypes().arrangeNullaryFunction(),
                     FunctionArgList(), SourceLocation());
@@ -345,6 +348,9 @@
 void CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
                                                 llvm::Constant **Decls,
                                                 unsigned NumDecls) {
+  // Initialize debug info if needed.
+  maybeInitializeDebugInfo();
+
   StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                 getTypes().arrangeNullaryFunction(),
                 FunctionArgList(), SourceLocation());
@@ -370,6 +376,9 @@
 void CodeGenFunction::GenerateCXXGlobalDtorsFunc(llvm::Function *Fn,
                   const std::vector<std::pair<llvm::WeakVH, llvm::Constant*> >
                                                 &DtorsAndObjects) {
+  // Initialize debug info if needed.
+  maybeInitializeDebugInfo();
+
   StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
                 getTypes().arrangeNullaryFunction(),
                 FunctionArgList(), SourceLocation());
@@ -406,6 +415,9 @@
   llvm::Function *fn = 
     CreateGlobalInitOrDestructFunction(CGM, FTy, "__cxx_global_array_dtor");
 
+  // Initialize debug info if needed.
+  maybeInitializeDebugInfo();
+
   StartFunction(GlobalDecl(), getContext().VoidTy, fn, FI, args,
                 SourceLocation());
 
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index a1a661b..5b37fe4 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -333,7 +333,10 @@
     
     FunctionArgs.push_back(Param);
   }
-  
+
+  // Initialize debug info if needed.
+  maybeInitializeDebugInfo();
+
   StartFunction(GlobalDecl(), ResultType, Fn, FnInfo, FunctionArgs,
                 SourceLocation());
 
diff --git a/test/CodeGenCXX/debug-info-blocks.cpp b/test/CodeGenCXX/debug-info-blocks.cpp
new file mode 100644
index 0000000..5b20db5
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-blocks.cpp
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 %s -gline-tables-only -fblocks -S -emit-llvm -o - | FileCheck %s
+
+struct A {
+  A();
+  A(const A &);
+  ~A();
+};
+
+void test() {
+  __block A a;
+}
+
+// CHECK: [ DW_TAG_subprogram ] [line 10] [local] [def] [__Block_byref_object_copy_]
+// CHECK: [ DW_TAG_subprogram ] [line 10] [local] [def] [__Block_byref_object_dispose_]
diff --git a/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp b/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
new file mode 100644
index 0000000..bdaf58c
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-global-ctor-dtor.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 %s -g -fno-use-cxa-atexit -S -emit-llvm -o - \
+// RUN:     | FileCheck %s --check-prefix=CHECK-NOKEXT
+// RUN: %clang_cc1 %s -g -fno-use-cxa-atexit -fapple-kext -S -emit-llvm -o - \
+// RUN:     | FileCheck %s --check-prefix=CHECK-KEXT
+
+class A {
+ public:
+  A() {}
+  virtual ~A() {}
+};
+
+A glob;
+A array[2];
+
+void foo() {
+  static A stat;
+}
+
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 12] [local] [def] [__cxx_global_var_init]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 12] [local] [def] [__dtor_glob]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 13] [local] [def] [__cxx_global_var_init1]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 13] [local] [def] [__cxx_global_array_dtor]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 13] [local] [def] [__dtor_]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line 16] [local] [def] [__dtor__ZZ3foovE4stat]
+// CHECK-NOKEXT: [ DW_TAG_subprogram ] [line {{.*}}] [local] [def] [_GLOBAL__I_a]
+
+// CHECK-KEXT: [ DW_TAG_subprogram ] [line {{.*}}] [local] [def] [_GLOBAL__D_a]
diff --git a/test/CodeGenCXX/debug-info-thunk.cpp b/test/CodeGenCXX/debug-info-thunk.cpp
new file mode 100644
index 0000000..58dd028
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-thunk.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 %s -g -S -emit-llvm -o - | FileCheck %s
+
+struct A {
+  virtual void f();
+};
+
+struct B {
+  virtual void f();
+};
+
+struct C : A, B {
+  virtual void f();
+};
+
+void C::f() { }
+
+// CHECK: [ DW_TAG_subprogram ] [line 15] [def] [_ZThn8_N1C1fEv]