/// how aliases work.
if (Ref->isDeclaration())
return true;
-
- // 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))
- return true;
}
+ // Don't create an alias to a linker weak symbol. This avoids producing
+ // different COMDATs in different TUs. Another option would be to
+ // output the alias both for weak_odr and linkonce_odr, but that
+ // requires explicit comdat support in the IL.
+ if (llvm::GlobalValue::isWeakForLinker(TargetLinkage))
+ return true;
+
// Create the alias with no name.
llvm::GlobalAlias *Alias =
new llvm::GlobalAlias(AliasType, Linkage, "", Aliasee, &getModule());
// RUN: %clang_cc1 %s -triple x86_64-linux -emit-llvm -o - -mconstructor-aliases | FileCheck %s
namespace test1 {
-// test that we produce an alias when the destructor is weak_odr
+// test that we don't produce an alias when the destructor is weak_odr. The
+// reason to avoid it that another TU might have no explicit template
+// instantiation definition or declaration, causing it to to output only
+// one of the destructors as linkonce_odr, producing a different comdat.
+
+// CHECK-DAG: define weak_odr void @_ZN5test16foobarIvEC2Ev
+// CHECK-DAG: define weak_odr void @_ZN5test16foobarIvEC1Ev
-// CHECK-DAG: @_ZN5test16foobarIvEC1Ev = alias weak_odr void (%"struct.test1::foobar"*)* @_ZN5test16foobarIvEC2Ev
-// CHECK-DAG: define weak_odr void @_ZN5test16foobarIvEC2Ev(
template <typename T> struct foobar {
foobar() {}
};