From e24f740ec883203d7bac7edd21631ef1dc6d2b8e Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 23 Jan 2017 16:57:14 +0000
Subject: [PATCH] Revert "DebugInfo: Omit class definitions even in the
 presence of available_externally vtables"

Patch crashing on a bootstrapping sanitizer bot:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/679

Reverting while I investigate.

This reverts commit r292768.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@292801 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGDebugInfo.cpp                 | 29 +++++++--------------
 lib/CodeGen/CGDebugInfo.h                   |  1 -
 lib/CodeGen/CGVTables.cpp                   |  7 +++--
 test/CodeGenCXX/debug-info-class-optzns.cpp | 16 ------------
 4 files changed, 13 insertions(+), 40 deletions(-)
 delete mode 100644 test/CodeGenCXX/debug-info-class-optzns.cpp

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 702ae01acf..c3dd53f12e 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -1714,26 +1714,7 @@ void CGDebugInfo::completeType(const RecordDecl *RD) {
     completeRequiredType(RD);
 }
 
-/// Return true if the class or any of its methods are marked dllimport.
-static bool isClassOrMethodDLLImport(const CXXRecordDecl *RD) {
-  if (RD->hasAttr<DLLImportAttr>())
-    return true;
-  for (const CXXMethodDecl *MD : RD->methods())
-    if (MD->hasAttr<DLLImportAttr>())
-      return true;
-  return false;
-}
-
 void CGDebugInfo::completeClassData(const RecordDecl *RD) {
-  if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
-    if (CGM.getVTableLinkage(CXXRD) ==
-            llvm::GlobalValue::AvailableExternallyLinkage &&
-        !isClassOrMethodDLLImport(CXXRD))
-      return;
-  completeClass(RD);
-}
-
-void CGDebugInfo::completeClass(const RecordDecl *RD) {
   if (DebugKind <= codegenoptions::DebugLineTablesOnly)
     return;
   QualType Ty = CGM.getContext().getRecordType(RD);
@@ -1779,6 +1760,16 @@ static bool isDefinedInClangModule(const RecordDecl *RD) {
   return true;
 }
 
+/// Return true if the class or any of its methods are marked dllimport.
+static bool isClassOrMethodDLLImport(const CXXRecordDecl *RD) {
+  if (RD->hasAttr<DLLImportAttr>())
+    return true;
+  for (const CXXMethodDecl *MD : RD->methods())
+    if (MD->hasAttr<DLLImportAttr>())
+      return true;
+  return false;
+}
+
 static bool shouldOmitDefinition(codegenoptions::DebugInfoKind DebugKind,
                                  bool DebugTypeExtRefs, const RecordDecl *RD,
                                  const LangOptions &LangOpts) {
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index ea451d0548..ac2e8dd2e0 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -409,7 +409,6 @@ public:
   void completeType(const RecordDecl *RD);
   void completeRequiredType(const RecordDecl *RD);
   void completeClassData(const RecordDecl *RD);
-  void completeClass(const RecordDecl *RD);
 
   void completeTemplateDefinition(const ClassTemplateSpecializationDecl &SD);
 
diff --git a/lib/CodeGen/CGVTables.cpp b/lib/CodeGen/CGVTables.cpp
index 24c7f15a08..04c5cfe536 100644
--- a/lib/CodeGen/CGVTables.cpp
+++ b/lib/CodeGen/CGVTables.cpp
@@ -744,10 +744,9 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
     switch (keyFunction->getTemplateSpecializationKind()) {
       case TSK_Undeclared:
       case TSK_ExplicitSpecialization:
-        assert((def || CodeGenOpts.OptimizationLevel > 0 ||
-                CodeGenOpts.getDebugInfo() != codegenoptions::NoDebugInfo) &&
-               "Shouldn't query vtable linkage without key function, "
-               "optimizations, or debug info");
+        assert((def || CodeGenOpts.OptimizationLevel > 0) &&
+               "Shouldn't query vtable linkage without key function or "
+               "optimizations");
         if (!def && CodeGenOpts.OptimizationLevel > 0)
           return llvm::GlobalVariable::AvailableExternallyLinkage;
 
diff --git a/test/CodeGenCXX/debug-info-class-optzns.cpp b/test/CodeGenCXX/debug-info-class-optzns.cpp
deleted file mode 100644
index 08f045659b..0000000000
--- a/test/CodeGenCXX/debug-info-class-optzns.cpp
+++ /dev/null
@@ -1,16 +0,0 @@
-// RUN: %clang_cc1 -triple x86_64-unknown_unknown -emit-llvm -debug-info-kind=limited %s -O1 -o - | FileCheck %s
-
-// Ensure class definitions are not emitted to debug info just because the
-// vtable is emitted for optimization purposes (as available_externally). The
-// class definition debug info should only go where the vtable is actually
-// emitted into the object file.
-
-// CHECK: @_ZTV3foo = available_externally
-// CHECK: !DICompositeType(tag: DW_TAG_structure_type, name: "foo"
-// CHECK-SAME: DIFlagFwdDecl
-
-struct foo {
-  virtual void f();
-};
-
-foo f;
-- 
2.40.0