[PATCH v14 09/26] c++: Implement __add_pointer built-in trait

[Jason Merrill]

On 2/28/24 11:26, Ken Matsui wrote:
> This patch implements built-in trait for std::add_pointer.

OK.

> gcc/cp/ChangeLog:
> 
> 	* cp-trait.def: Define __add_pointer.
> 	* semantics.cc (finish_trait_type): Handle CPTK_ADD_POINTER.
> 
> gcc/testsuite/ChangeLog:
> 
> 	* g++.dg/ext/has-builtin-1.C: Test existence of __add_pointer.
> 	* g++.dg/ext/add_pointer.C: New test.
> 
> Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
> ---
>   gcc/cp/cp-trait.def                      |  1 +
>   gcc/cp/semantics.cc                      |  9 ++++++
>   gcc/testsuite/g++.dg/ext/add_pointer.C   | 39 ++++++++++++++++++++++++
>   gcc/testsuite/g++.dg/ext/has-builtin-1.C |  3 ++
>   4 files changed, 52 insertions(+)
>   create mode 100644 gcc/testsuite/g++.dg/ext/add_pointer.C
> 
> diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
> index 05514a51c21..63f879287ce 100644
> --- a/gcc/cp/cp-trait.def
> +++ b/gcc/cp/cp-trait.def
> @@ -48,6 +48,7 @@
>   #define DEFTRAIT_TYPE_DEFAULTED
>   #endif
>   
> +DEFTRAIT_TYPE (ADD_POINTER, "__add_pointer", 1)
>   DEFTRAIT_EXPR (HAS_NOTHROW_ASSIGN, "__has_nothrow_assign", 1)
>   DEFTRAIT_EXPR (HAS_NOTHROW_CONSTRUCTOR, "__has_nothrow_constructor", 1)
>   DEFTRAIT_EXPR (HAS_NOTHROW_COPY, "__has_nothrow_copy", 1)
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 1794e83baa2..635441a7a90 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -12776,6 +12776,15 @@ finish_trait_type (cp_trait_kind kind, tree type1, tree type2,
>   
>     switch (kind)
>       {
> +    case CPTK_ADD_POINTER:
> +      if (FUNC_OR_METHOD_TYPE_P (type1)
> +	  && (type_memfn_quals (type1) != TYPE_UNQUALIFIED
> +	      || type_memfn_rqual (type1) != REF_QUAL_NONE))
> +	return type1;
> +      if (TYPE_REF_P (type1))
> +	type1 = TREE_TYPE (type1);
> +      return build_pointer_type (type1);
> +
>       case CPTK_REMOVE_CV:
>         return cv_unqualified (type1);
>   
> diff --git a/gcc/testsuite/g++.dg/ext/add_pointer.C b/gcc/testsuite/g++.dg/ext/add_pointer.C
> new file mode 100644
> index 00000000000..c405cdd0feb
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ext/add_pointer.C
> @@ -0,0 +1,39 @@
> +// { dg-do compile { target c++11 } }
> +
> +#define SA(X) static_assert((X),#X)
> +
> +class ClassType { };
> +
> +SA(__is_same(__add_pointer(int), int*));
> +SA(__is_same(__add_pointer(int*), int**));
> +SA(__is_same(__add_pointer(const int), const int*));
> +SA(__is_same(__add_pointer(int&), int*));
> +SA(__is_same(__add_pointer(ClassType*), ClassType**));
> +SA(__is_same(__add_pointer(ClassType), ClassType*));
> +SA(__is_same(__add_pointer(void), void*));
> +SA(__is_same(__add_pointer(const void), const void*));
> +SA(__is_same(__add_pointer(volatile void), volatile void*));
> +SA(__is_same(__add_pointer(const volatile void), const volatile void*));
> +
> +void f1();
> +using f1_type = decltype(f1);
> +using pf1_type = decltype(&f1);
> +SA(__is_same(__add_pointer(f1_type), pf1_type));
> +
> +void f2() noexcept; // PR libstdc++/78361
> +using f2_type = decltype(f2);
> +using pf2_type = decltype(&f2);
> +SA(__is_same(__add_pointer(f2_type), pf2_type));
> +
> +using fn_type = void();
> +using pfn_type = void(*)();
> +SA(__is_same(__add_pointer(fn_type), pfn_type));
> +
> +SA(__is_same(__add_pointer(void() &), void() &));
> +SA(__is_same(__add_pointer(void() & noexcept), void() & noexcept));
> +SA(__is_same(__add_pointer(void() const), void() const));
> +SA(__is_same(__add_pointer(void(...) &), void(...) &));
> +SA(__is_same(__add_pointer(void(...) & noexcept), void(...) & noexcept));
> +SA(__is_same(__add_pointer(void(...) const), void(...) const));
> +
> +SA(__is_same(__add_pointer(void() __restrict), void() __restrict));
> diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> index b1430e9bd8b..9d861398bae 100644
> --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> @@ -2,6 +2,9 @@
>   // { dg-do compile }
>   // Verify that __has_builtin gives the correct answer for C++ built-ins.
>   
> +#if !__has_builtin (__add_pointer)
> +# error "__has_builtin (__add_pointer) failed"
> +#endif
>   #if !__has_builtin (__builtin_addressof)
>   # error "__has_builtin (__builtin_addressof) failed"
>   #endif