From 4c489c7030e9310d7d9dfe073c399b7076c37e71 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Fri, 5 Mar 2010 01:21:10 +0000
Subject: Don't produce an alias for a destructor if the target is weak.

This fixes bootstrap on ELF systems :-)

llvm-svn: 97773
---
 clang/lib/CodeGen/CGCXX.cpp | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

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

diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp
index 4889fc08f48..cd5d64697d1 100644
--- a/clang/lib/CodeGen/CGCXX.cpp
+++ b/clang/lib/CodeGen/CGCXX.cpp
@@ -109,6 +109,16 @@ bool CodeGenModule::TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D) {
                                   GlobalDecl(BaseD, Dtor_Base));
 }
 
+static bool isWeakForLinker(llvm::GlobalValue::LinkageTypes Linkage) {
+  return (Linkage == llvm::GlobalValue::AvailableExternallyLinkage ||
+          Linkage == llvm::GlobalValue::WeakAnyLinkage ||
+          Linkage == llvm::GlobalValue::WeakODRLinkage ||
+          Linkage == llvm::GlobalValue::LinkOnceAnyLinkage ||
+          Linkage == llvm::GlobalValue::LinkOnceODRLinkage ||
+          Linkage == llvm::GlobalValue::CommonLinkage ||
+          Linkage == llvm::GlobalValue::ExternalWeakLinkage);
+}
+
 /// Try to emit a definition as a global alias for another definition.
 bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
                                              GlobalDecl TargetDecl) {
@@ -142,6 +152,12 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
     return true;
   }
 
+  llvm::GlobalValue::LinkageTypes TargetLinkage
+    = getFunctionLinkage(cast<FunctionDecl>(TargetDecl.getDecl()));
+
+  if (isWeakForLinker(TargetLinkage))
+    return true;
+
   // Derive the type for the alias.
   const llvm::PointerType *AliasType
     = getTypes().GetFunctionType(AliasDecl)->getPointerTo();
-- 
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