diff options
Diffstat (limited to 'clang')
| -rw-r--r-- | clang/lib/CodeGen/CGCXX.cpp | 14 | ||||
| -rw-r--r-- | clang/test/CodeGenCXX/alias-available-externally.cpp | 20 |
2 files changed, 26 insertions, 8 deletions
diff --git a/clang/lib/CodeGen/CGCXX.cpp b/clang/lib/CodeGen/CGCXX.cpp index 40f1bc426ff..d33555f7bc2 100644 --- a/clang/lib/CodeGen/CGCXX.cpp +++ b/clang/lib/CodeGen/CGCXX.cpp @@ -134,6 +134,11 @@ 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); @@ -156,14 +161,7 @@ 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) && - (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. + if (llvm::GlobalValue::isDiscardableIfUnused(Linkage)) { addReplacement(MangledName, Aliasee); return false; } diff --git a/clang/test/CodeGenCXX/alias-available-externally.cpp b/clang/test/CodeGenCXX/alias-available-externally.cpp new file mode 100644 index 00000000000..acc59620a3b --- /dev/null +++ b/clang/test/CodeGenCXX/alias-available-externally.cpp @@ -0,0 +1,20 @@ +// 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. +// The destructors have different return type for different targets. +// CHECK: define linkonce_odr {{.*}} @_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; |
