llvm-capstone/clang/test/SemaCXX/attr-exclude_from_explicit_instantiation.extern_declaration.cpp
Louis Dionne d269579a97 [clang] Add the exclude_from_explicit_instantiation attribute
Summary:
This attribute allows excluding a member of a class template from being part
of an explicit template instantiation of that class template. This also makes
sure that code using such a member will not take for granted that an external
instantiation exists in another translation unit. The attribute was discussed
on cfe-dev at [1] and is primarily motivated by the removal of always_inline
in libc++ to control what's part of the ABI (see links in [1]).

[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html

rdar://problem/43428125

Reviewers: rsmith

Subscribers: dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D51789

llvm-svn: 343790
2018-10-04 15:49:42 +00:00

70 lines
2.6 KiB
C++

// RUN: %clang_cc1 -Wno-unused-local-typedef -fsyntax-only -verify %s
// Test that extern instantiation declarations cause members marked with
// the exclude_from_explicit_instantiation attribute to be instantiated in
// the current TU.
#define EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__((exclude_from_explicit_instantiation))
template <class T>
struct Foo {
EXCLUDE_FROM_EXPLICIT_INSTANTIATION inline void non_static_member_function1();
EXCLUDE_FROM_EXPLICIT_INSTANTIATION void non_static_member_function2();
EXCLUDE_FROM_EXPLICIT_INSTANTIATION static inline void static_member_function1();
EXCLUDE_FROM_EXPLICIT_INSTANTIATION static void static_member_function2();
EXCLUDE_FROM_EXPLICIT_INSTANTIATION static int static_data_member;
struct EXCLUDE_FROM_EXPLICIT_INSTANTIATION member_class1 {
static void static_member_function() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
};
struct member_class2 {
EXCLUDE_FROM_EXPLICIT_INSTANTIATION static void static_member_function() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
};
};
template <class T>
inline void Foo<T>::non_static_member_function1() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
template <class T>
void Foo<T>::non_static_member_function2() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
template <class T>
inline void Foo<T>::static_member_function1() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
template <class T>
void Foo<T>::static_member_function2() {
using Fail = typename T::invalid; // expected-error{{no type named 'invalid' in 'Empty'}}
}
template <class T>
int Foo<T>::static_data_member = T::invalid; // expected-error{{no member named 'invalid' in 'Empty'}}
struct Empty { };
extern template struct Foo<Empty>;
int main() {
Foo<Empty> foo;
foo.non_static_member_function1(); // expected-note{{in instantiation of}}
foo.non_static_member_function2(); // expected-note{{in instantiation of}}
Foo<Empty>::static_member_function1(); // expected-note{{in instantiation of}}
Foo<Empty>::static_member_function2(); // expected-note{{in instantiation of}}
(void)foo.static_data_member; // expected-note{{in instantiation of}}
Foo<Empty>::member_class1::static_member_function(); // expected-note{{in instantiation of}}
Foo<Empty>::member_class2::static_member_function(); // expected-note{{in instantiation of}}
}