mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-04-19 06:20:27 +08:00
Code Issues Packages Projects Releases Wiki Activity

libstdc++: Fix std::move_only_function for incomplete parameter types

Browse Source 
The std::move_only_function::__param_t alias template attempts to
optimize argument passing for the invoker, by passing by rvalue
reference for types that are non-trivial or large. However, the
precondition for is_trivally_copyable makes it unsuitable for using
here, and can cause ODR violations. Just use is_scalar instead, and pass
all class types (even small, trivial ones) by value.

libstdc++-v3/ChangeLog:

	* include/bits/mofunc_impl.h (move_only_function::__param_t):
	Use __is_scalar instead of is_trivially_copyable.
	* testsuite/20_util/move_only_function/call.cc: Check parameters
	involving incomplete types.
This commit is contained in:
Jonathan Wakely 2022-10-18 20:49:42 +01:00
parent a9de836c2b
commit 33de0ffcf0
2 changed files with 12 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
libstdc++-v3/include/bits/mofunc_impl.h
View File

@ -205,10 +205,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
private:
template<typename _Tp>
using __param_t
= __conditional_t<is_trivially_copyable_v<_Tp>
&& sizeof(_Tp) <= sizeof(long),
_Tp, _Tp&&>;
using __param_t = __conditional_t<is_scalar_v<_Tp>, _Tp, _Tp&&>;
using _Invoker = _Res (*)(_Mofunc_base _GLIBCXX_MOF_CV*,
__param_t<_ArgTypes>...) noexcept(_Noex);

11
libstdc++-v3/testsuite/20_util/move_only_function/call.cc
View File

@ -191,10 +191,21 @@ test04()
VERIFY( std::move(std::as_const(f5))() == 3 );
}
struct Incomplete;
void
test_params()
{
std::move_only_function<void(Incomplete)> f1;
std::move_only_function<void(Incomplete&)> f2;
std::move_only_function<void(Incomplete&&)> f3;
}
int main()
{
test01();
test02();
test03();
test04();
test_params();
}