Revert "Produce direct calls instead of alias to linkonce_odr functions."

This reverts commit r194046.
Debugging a bootstrap issue.

llvm-svn: 194047

1 files changed, 18 insertions, 23 deletions

diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp
index ab45e321cbb..25f3e6f4daa 100644
--- a/clang/lib/CodeGen/CGCXX.cpp
+++ b/clang/lib/CodeGen/CGCXX.cpp
@@ -112,13 +112,28 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
   // support aliases with that linkage, fail.
   llvm::GlobalValue::LinkageTypes Linkage = getFunctionLinkage(AliasDecl);
 
+  llvm::GlobalValue::LinkageTypes TargetLinkage
+    = getFunctionLinkage(TargetDecl);
+
+  // Don't create an alias to a linker weak symbol unless we know we can do
+  // that in every TU. This avoids producing different COMDATs in different
+  // TUs.
+  if (llvm::GlobalValue::isWeakForLinker(TargetLinkage)) {
+    if (!InEveryTU)
+      return true;
+
+    // In addition to making sure we produce it in every TU, we have to make
+    // sure llvm keeps it.
+    // FIXME: Instead of outputting an alias we could just replace every use of
+    // AliasDecl with TargetDecl.
+    assert(Linkage == TargetLinkage);
+    Linkage = llvm::GlobalValue::WeakODRLinkage;
+  }
+
   // We can't use an alias if the linkage is not valid for one.
   if (!llvm::GlobalAlias::isValidLinkage(Linkage))
     return true;
 
-  llvm::GlobalValue::LinkageTypes TargetLinkage =
-      getFunctionLinkage(TargetDecl);
-
   // Check if we have it already.
   StringRef MangledName = getMangledName(AliasDecl);
   llvm::GlobalValue *Entry = GetGlobalValue(MangledName);
@@ -137,26 +152,6 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
   if (Ref->getType() != AliasType)
     Aliasee = llvm::ConstantExpr::getBitCast(Ref, AliasType);
 
-  // Don't create an alias to a linker weak symbol unless we know we can do
-  // that in every TU. This avoids producing different COMDATs in different
-  // TUs.
-  if (llvm::GlobalValue::isWeakForLinker(TargetLinkage)) {
-    if (!InEveryTU)
-      return true;
-
-    assert(Linkage == TargetLinkage);
-    // Instead of creating as alias to a linkonce_odr, replace all of the uses
-    // of the aliassee.
-    if (TargetLinkage == llvm::GlobalValue::LinkOnceODRLinkage) {
-      if (!Entry)
-        return false;
-
-      Entry->replaceAllUsesWith(Aliasee);
-      Entry->eraseFromParent();
-      return false;
-    }
-  }
-
   // Create the alias with no name.
   llvm::GlobalAlias *Alias = 
     new llvm::GlobalAlias(AliasType, Linkage, "", Aliasee, &getModule());