r281057 - [DebugInfo] Ensure complete type is emitted with -fstandalone-debug

Reid Kleckner via cfe-commits cfe-commits at lists.llvm.org
Fri Sep 9 10:03:53 PDT 2016

Author: rnk
Date: Fri Sep  9 12:03:53 2016
New Revision: 281057

URL: http://llvm.org/viewvc/llvm-project?rev=281057&view=rev
[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


Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=281057&r1=281056&r2=281057&view=diff
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Fri Sep  9 12:03:53 2016
@@ -1648,9 +1648,13 @@ void CGDebugInfo::completeRequiredType(c
   if (DebugKind <= codegenoptions::DebugLineTablesOnly)
-  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())

Modified: cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp?rev=281057&r1=281056&r2=281057&view=diff
--- cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-class-nolimit.cpp Fri Sep  9 12:03:53 2016
@@ -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 {
+  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

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