From b06bcde1ab0dd598c9d27c45e1d7553745c8077e Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Mon, 23 Jan 2017 02:24:03 +0000
Subject: DebugInfo: Omit class definitions even in the presence of
 available_externally vtables

To ensure optimization level doesn't pessimize the -fstandalone-debug
vtable debug info optimization (where class definitions are only emitted
where the vtable is emitted - reducing redundant debug info) ensure the
debug info class definition is still omitted when an
available_externally vtable definition is emitted for optimization
purposes.

llvm-svn: 292768
---
 clang/lib/CodeGen/CGDebugInfo.cpp | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

(limited to 'clang/lib/CodeGen/CGDebugInfo.cpp')

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index c3dd53f12e2..702ae01acf3 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1714,7 +1714,26 @@ 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);
@@ -1760,16 +1779,6 @@ 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) {
-- 
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