From 22466a92e164f43aba45e9722cf62ee1bd47b246 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Fri, 9 Sep 2016 17:03:53 +0000
Subject: [PATCH] [DebugInfo] Ensure complete type is emitted with
 -fstandalone-debug

The logic for upgrading a class from a forward decl to a complete type
was not checking the debug info emission level before applying the
vtable optimization. This meant we ended up without debug info for a
class which was required to be complete. I noticed it because it
triggered an assertion during CodeView emission, but that's a separate
issue.

llvm-svn: 281057
---
 clang/lib/CodeGen/CGDebugInfo.cpp             | 10 ++++---
 .../CodeGenCXX/debug-info-class-nolimit.cpp   | 27 ++++++++++++++++---
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 713772244618..c2878c38f6ed 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1648,9 +1648,13 @@ void CGDebugInfo::completeRequiredType(const RecordDecl *RD) {
   if (DebugKind <= codegenoptions::DebugLineTablesOnly)
     return;
 
-  if (const auto *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
-    if (CXXDecl->isDynamicClass())
-      return;
+  // If this is a dynamic class and we're emitting limited debug info, wait
+  // until the vtable is emitted to complete the class debug info.
+  if (DebugKind <= codegenoptions::LimitedDebugInfo) {
+    if (const auto *CXXDecl = dyn_cast<CXXRecordDecl>(RD))
+      if (CXXDecl->isDynamicClass())
+        return;
+  }
 
   if (DebugTypeExtRefs && RD->isFromASTFile())
     return;
diff --git a/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp b/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
index ce47f9fa495a..4b05fd6e87d8 100644
--- a/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
+++ b/clang/test/CodeGenCXX/debug-info-class-nolimit.cpp
@@ -1,8 +1,29 @@
-// RUN: %clang_cc1 -triple x86_64-unk-unk -debug-info-kind=standalone -o - -emit-llvm %s | FileCheck %s
-// On Darwin, "full" debug info is the default, so really these tests are
-// identical, as cc1 no longer chooses the effective value of DebugInfoKind.
 // RUN: %clang_cc1 -triple x86_64-apple-darwin -debug-info-kind=standalone -o - -emit-llvm %s | FileCheck %s
 
+// We had a bug in -fstandalone-debug where UnicodeString would not be completed
+// when it was required to be complete. This orginally manifested as an
+// assertion in CodeView emission on Windows with some dllexport stuff, but it's
+// more general than that.
+
+struct UnicodeString;
+struct GetFwdDecl {
+  static UnicodeString format;
+};
+GetFwdDecl force_fwd_decl;
+struct UnicodeString {
+private:
+  virtual ~UnicodeString();
+};
+struct UseCompleteType {
+  UseCompleteType();
+  ~UseCompleteType();
+  UnicodeString currencySpcAfterSym[1];
+};
+UseCompleteType require_complete;
+// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "UnicodeString"
+// CHECK-NOT:              DIFlagFwdDecl
+// CHECK-SAME:             ){{$}}
+
 namespace rdar14101097_1 { // see also PR16214
 // Check that we emit debug info for the definition of a struct if the
 // definition is available, even if it's used via a pointer wrapped in a