From 0a050f7d56039bab7556e08b359e06d329977b6b Mon Sep 17 00:00:00 2001
From: Adrian Prantl <aprantl@apple.com>
Date: Thu, 9 May 2013 23:16:27 +0000
Subject: [PATCH] Debug Info: Fix a problem that resulted in missing
 DW_AT_specifications for C++ constructors.

If the DIType for a class was generated by
CGDebugInfo::createContextChain(), the cache contains only a
limited DIType wihtout any declarations. Since EmitFunctionStart()
needs to find the canonical declaration for each method, we
construct the complete type before emitting any method.

rdar://problem/13116508

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181561 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CodeGenModule.cpp              | 18 +++++++
 lib/CodeGen/CodeGenModule.h                |  1 +
 test/CodeGenCXX/debug-info-decl-nested.cpp | 61 ++++++++++++++++++++++
 3 files changed, 80 insertions(+)
 create mode 100644 test/CodeGenCXX/debug-info-decl-nested.cpp

diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 1da4e87c0a..717ed17dd4 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -1232,6 +1232,23 @@ CodeGenModule::shouldEmitFunction(const FunctionDecl *F) {
   return !isTriviallyRecursive(F);
 }
 
+/// If the type for the method's class was generated by
+/// CGDebugInfo::createContextChain(), the cache contains only a
+/// limited DIType without any declarations. Since EmitFunctionStart()
+/// needs to find the canonical declaration for each method, we need
+/// to construct the complete type prior to emitting the method.
+void CodeGenModule::CompleteDIClassType(const CXXMethodDecl* D) {
+  if (!D->isInstance())
+    return;
+
+  if (CGDebugInfo *DI = getModuleDebugInfo())
+    if (getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) {
+      const PointerType *ThisPtr =
+        cast<PointerType>(D->getThisType(getContext()));
+      DI->getOrCreateRecordType(ThisPtr->getPointeeType(), D->getLocation());
+    }
+}
+
 void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
   const ValueDecl *D = cast<ValueDecl>(GD.getDecl());
 
@@ -1246,6 +1263,7 @@ void CodeGenModule::EmitGlobalDefinition(GlobalDecl GD) {
       return;
 
     if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
+      CompleteDIClassType(Method);
       // Make sure to emit the definition(s) before we emit the thunks.
       // This is necessary for the generation of certain thunks.
       if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(Method))
diff --git a/lib/CodeGen/CodeGenModule.h b/lib/CodeGen/CodeGenModule.h
index 1d6c7e98e5..e4e29a8d6b 100644
--- a/lib/CodeGen/CodeGenModule.h
+++ b/lib/CodeGen/CodeGenModule.h
@@ -1025,6 +1025,7 @@ private:
 
   void EmitNamespace(const NamespaceDecl *D);
   void EmitLinkageSpec(const LinkageSpecDecl *D);
+  void CompleteDIClassType(const CXXMethodDecl* D);
 
   /// EmitCXXConstructors - Emit constructors (base, complete) from a
   /// C++ constructor Decl.
diff --git a/test/CodeGenCXX/debug-info-decl-nested.cpp b/test/CodeGenCXX/debug-info-decl-nested.cpp
new file mode 100644
index 0000000000..7c8bd1facf
--- /dev/null
+++ b/test/CodeGenCXX/debug-info-decl-nested.cpp
@@ -0,0 +1,61 @@
+// RUN: %clang_cc1 -std=c++11 -g -O0 -emit-llvm -g -triple x86_64-apple-darwin %s -o %t
+// RUN: cat %t | FileCheck %s -check-prefix=CHECK0
+// RUN: cat %t | FileCheck %s -check-prefix=CHECK1
+// RUN: cat %t | FileCheck %s -check-prefix=CHECK2
+//
+// This test ensures that we associate a declaration with the
+// definition of the constructor for OuterClass. The declaration is
+// necessary so the backend can emit the DW_AT_specification attribute
+// for the definition.
+//
+// rdar://problem/13116508
+
+class Foo;
+class OuterClass
+{
+  static class InnerClass {
+  public:
+    InnerClass(); // Here createContextChain() generates a limited type for OuterClass.
+  } theInnerClass;
+// CHECK0: [[DECL:[0-9]+]] = {{.*}} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [private] [OuterClass]
+  OuterClass(const Foo *); // line 10
+};
+OuterClass::InnerClass OuterClass::theInnerClass; // This toplevel decl causes InnerClass to be generated.
+// CHECK0: metadata {{.*}}, metadata ![[DECL]], metadata {{.*}}, i32 [[@LINE+1]]} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [OuterClass]
+OuterClass::OuterClass(const Foo *meta) { } // line 13
+
+
+
+
+
+class Foo1;
+class OuterClass1
+{
+  static class InnerClass1 {
+  public:
+    InnerClass1();
+  } theInnerClass1;
+// CHECK1: metadata {{.*}}, metadata ![[DECL:[0-9]+]], metadata {{.*}}, i32 [[@LINE+5]]} ; [ DW_TAG_subprogram ] [line [[@LINE+5]]] [def] [Bar]
+  void Bar(const Foo1 *);
+};
+OuterClass1::InnerClass1 OuterClass1::theInnerClass1;
+// CHECK1: [[DECL]] = {{.*}} ; [ DW_TAG_subprogram ] [line [[@LINE-3]]] [private] [Bar]
+void OuterClass1::Bar(const Foo1 *meta) { }
+
+
+
+
+
+class Foo2;
+class OuterClass2
+{
+  static class InnerClass2 {
+  public:
+    InnerClass2();
+  } theInnerClass2;
+// CHECK2: [[DECL:[0-9]+]] = {{.*}} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [private] [~OuterClass2]
+  ~OuterClass2(); // line 10
+};
+OuterClass2::InnerClass2 OuterClass2::theInnerClass2;
+// CHECK2: metadata {{.*}}, metadata ![[DECL]], metadata {{.*}}, i32 [[@LINE+1]]} ; [ DW_TAG_subprogram ] [line [[@LINE+1]]] [def] [~OuterClass2]
+OuterClass2::~OuterClass2() { }
-- 
2.40.0