From dedd27fc62528220ec4cd539498567238d832e78 Mon Sep 17 00:00:00 2001
From: David Blaikie <dblaikie@gmail.com>
Date: Fri, 13 Sep 2013 18:45:00 +0000
Subject: [PATCH] DebugInfo: omit debug info for friends

GCC ToT doesn't do this & it's worth about 3.2% on Clang's DWO file size
with Clang. Some or all of this may be due to things like r190715 which
could have source fixes/improvements, but it's not clear that's the case
and that doesn't help other source bases.

llvm-svn: 190716
---
 clang/lib/CodeGen/CGDebugInfo.cpp           | 18 ------------------
 clang/lib/CodeGen/CGDebugInfo.h             |  5 -----
 clang/test/CodeGenCXX/debug-info-friend.cpp |  5 ++++-
 3 files changed, 4 insertions(+), 24 deletions(-)

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index f81d2cf683e5..0069d577f24a 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -1139,23 +1139,6 @@ CollectCXXMemberFunctions(const CXXRecordDecl *RD, llvm::DIFile Unit,
   }
 }
 
-/// CollectCXXFriends - A helper function to collect debug info for
-/// C++ base classes. This is used while creating debug info entry for
-/// a Record.
-void CGDebugInfo::
-CollectCXXFriends(const CXXRecordDecl *RD, llvm::DIFile Unit,
-                SmallVectorImpl<llvm::Value *> &EltTys,
-                llvm::DIType RecordTy) {
-  for (CXXRecordDecl::friend_iterator BI = RD->friend_begin(),
-         BE = RD->friend_end(); BI != BE; ++BI) {
-    if ((*BI)->isUnsupportedFriend())
-      continue;
-    if (TypeSourceInfo *TInfo = (*BI)->getFriendType())
-      EltTys.push_back(DBuilder.createFriend(
-          RecordTy, getOrCreateType(TInfo->getType(), Unit)));
-  }
-}
-
 /// CollectCXXBases - A helper function to collect debug info for
 /// C++ base classes. This is used while creating debug info entry for
 /// a Record.
@@ -1528,7 +1511,6 @@ llvm::DIType CGDebugInfo::CreateTypeDefinition(const RecordType *Ty) {
   CollectRecordFields(RD, DefUnit, EltTys, FwdDecl);
   if (CXXDecl) {
     CollectCXXMemberFunctions(CXXDecl, DefUnit, EltTys, FwdDecl);
-    CollectCXXFriends(CXXDecl, DefUnit, EltTys, FwdDecl);
   }
 
   LexicalBlockStack.pop_back();
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index d480d9bbc872..0ca274f56881 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -155,11 +155,6 @@ class CGDebugInfo {
                                  SmallVectorImpl<llvm::Value *> &E,
                                  llvm::DIType T);
 
-  void CollectCXXFriends(const CXXRecordDecl *Decl,
-                       llvm::DIFile F,
-                       SmallVectorImpl<llvm::Value *> &EltTys,
-                       llvm::DIType RecordTy);
-
   void CollectCXXBases(const CXXRecordDecl *Decl,
                        llvm::DIFile F,
                        SmallVectorImpl<llvm::Value *> &EltTys,
diff --git a/clang/test/CodeGenCXX/debug-info-friend.cpp b/clang/test/CodeGenCXX/debug-info-friend.cpp
index cf6651cde18e..b103b142a2ae 100644
--- a/clang/test/CodeGenCXX/debug-info-friend.cpp
+++ b/clang/test/CodeGenCXX/debug-info-friend.cpp
@@ -14,4 +14,7 @@ struct MyFriend {
   }
 };
 
-// CHECK: DW_TAG_friend
+// Emitting debug info for friends unnecessarily bloats debug info without any
+// known benefit or debugger feature that requires it. Re-enable this is a
+// use-case appears.
+// CHECK-NOT: DW_TAG_friend