Implement P0722R3, destroying operator delete.

A destroying operator delete takes responsibility for calling the destructor
for the object it is deleting; this is intended to be useful for sized
delete of a class allocated with a trailing buffer, where the compiler can't
know the size of the allocation, and so would pass the wrong size to the
non-destroying sized operator delete.

gcc/c-family/
	* c-cppbuiltin.c (c_cpp_builtins): Define
	__cpp_impl_destroying_delete.
gcc/cp/
	* call.c (std_destroying_delete_t_p, destroying_delete_p): New.
	(aligned_deallocation_fn_p, usual_deallocation_fn_p): Use
	destroying_delete_p.
	(build_op_delete_call): Handle destroying delete.
	* decl2.c (coerce_delete_type): Handle destroying delete.
	* init.c (build_delete): Don't call dtor with destroying delete.
	* optimize.c (build_delete_destructor_body): Likewise.
libstdc++-v3/
	* libsupc++/new (std::destroying_delete_t): New.

From-SVN: r266053

1 files changed, 1 insertions, 0 deletions

diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
index 8dd6215..7daa3e3 100644
--- a/gcc/c-family/c-cppbuiltin.c
+++ b/gcc/c-family/c-cppbuiltin.c
@@ -980,6 +980,7 @@ c_cpp_builtins (cpp_reader *pfile)
 	  /* Set feature test macros for C++2a.  */
 	  cpp_define (pfile, "__cpp_conditional_explicit=201806");
 	  cpp_define (pfile, "__cpp_nontype_template_parameter_class=201806");
+	  cpp_define (pfile, "__cpp_impl_destroying_delete=201806");
 	}
       if (flag_concepts)
 	cpp_define (pfile, "__cpp_concepts=201507");