diff options
| -rw-r--r-- | clang/lib/CodeGen/CGCXX.cpp | 14 | ||||
| -rw-r--r-- | clang/test/CodeGenCXX/alias-available-externally.cpp | 19 |
2 files changed, 8 insertions, 25 deletions
diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp index d33555f7bc2..40f1bc426ff 100644 --- a/clang/lib/CodeGen/CGCXX.cpp +++ b/clang/lib/CodeGen/CGCXX.cpp @@ -134,11 +134,6 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl, llvm::GlobalValue::LinkageTypes TargetLinkage = getFunctionLinkage(TargetDecl); - // available_externally definitions aren't real definitions, so we cannot - // create an alias to one. - if (TargetLinkage == llvm::GlobalValue::AvailableExternallyLinkage) - return true; - // Check if we have it already. StringRef MangledName = getMangledName(AliasDecl); llvm::GlobalValue *Entry = GetGlobalValue(MangledName); @@ -161,7 +156,14 @@ bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl, // Instead of creating as alias to a linkonce_odr, replace all of the uses // of the aliasee. - if (llvm::GlobalValue::isDiscardableIfUnused(Linkage)) { + if (llvm::GlobalValue::isDiscardableIfUnused(Linkage) && + (TargetLinkage != llvm::GlobalValue::AvailableExternallyLinkage || + !TargetDecl.getDecl()->hasAttr<AlwaysInlineAttr>())) { + // FIXME: An extern template instantiation will create functions with + // linkage "AvailableExternally". In libc++, some classes also define + // members with attribute "AlwaysInline" and expect no reference to + // be generated. It is desirable to reenable this optimisation after + // corresponding LLVM changes. addReplacement(MangledName, Aliasee); return false; } diff --git a/clang/test/CodeGenCXX/alias-available-externally.cpp b/clang/test/CodeGenCXX/alias-available-externally.cpp deleted file mode 100644 index 264af558377..00000000000 --- a/clang/test/CodeGenCXX/alias-available-externally.cpp +++ /dev/null @@ -1,19 +0,0 @@ -// RUN: %clang_cc1 -O1 -std=c++11 -emit-llvm -disable-llvm-passes -o - %s | FileCheck %s -// Clang should not generate alias to available_externally definitions. -// Check that the destructor of Foo is defined. -// CHECK: define linkonce_odr void @_ZN3FooD2Ev -template <class CharT> -struct String { - String() {} - ~String(); -}; - -template <class CharT> -inline __attribute__((visibility("hidden"), always_inline)) -String<CharT>::~String() {} - -extern template struct String<char>; - -struct Foo : public String<char> { Foo() { String<char> s; } }; - -Foo f; |
