On Tue, 21 Mar 2023 at 16:40, Ken Matsui via Libstdc++ <
libstdc++@gcc.gnu.org> wrote:

> This patch implements built-in trait for std::is_unsigned.
>
> gcc/cp/ChangeLog:
>
>         * cp-trait.def: Define __is_unsigned.
>         * constraint.cc (diagnose_trait_expr): Handle CPTK_IS_UNSIGNED.
>         * semantics.cc (trait_expr_value): Likewise.
>         (finish_trait_expr): Likewise.
>
> gcc/testsuite/ChangeLog:
>
>         * g++.dg/ext/has-builtin-1.C: Test existence of __is_unsigned.
>         * g++.dg/ext/is_unsigned.C: New test.
> ---
>  gcc/cp/constraint.cc                     |  3 ++
>  gcc/cp/cp-trait.def                      |  1 +
>  gcc/cp/semantics.cc                      |  4 +++
>  gcc/testsuite/g++.dg/ext/has-builtin-1.C |  3 ++
>  gcc/testsuite/g++.dg/ext/is_unsigned.C   | 46 ++++++++++++++++++++++++
>  5 files changed, 57 insertions(+)
>  create mode 100644 gcc/testsuite/g++.dg/ext/is_unsigned.C
>
> diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
> index 273d15ab097..bc4c3d3ec57 100644
> --- a/gcc/cp/constraint.cc
> +++ b/gcc/cp/constraint.cc
> @@ -3747,6 +3747,9 @@ diagnose_trait_expr (tree expr, tree args)
>      case CPTK_IS_UNION:
>        inform (loc, "  %qT is not a union", t1);
>        break;
> +    case CPTK_IS_UNSIGNED:
> +      inform (loc, "  %qT is not an unsigned type", t1);
> +      break;
>      case CPTK_IS_AGGREGATE:
>        inform (loc, "  %qT is not an aggregate", t1);
>        break;
> diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
> index bac593c0094..9f1fff9043e 100644
> --- a/gcc/cp/cp-trait.def
> +++ b/gcc/cp/cp-trait.def
> @@ -82,6 +82,7 @@ DEFTRAIT_EXPR (IS_TRIVIALLY_ASSIGNABLE,
> "__is_trivially_assignable", 2)
>  DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE,
> "__is_trivially_constructible", -1)
>  DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
>  DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
> +DEFTRAIT_EXPR (IS_UNSIGNED, "__is_unsigned", 1)
>  DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY,
> "__reference_constructs_from_temporary", 2)
>  DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY,
> "__reference_converts_from_temporary", 2)
>  /* FIXME Added space to avoid direct usage in GCC 13.  */
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 87c2e8a7111..d43e2543490 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -12031,6 +12031,9 @@ trait_expr_value (cp_trait_kind kind, tree type1,
> tree type2)
>      case CPTK_IS_UNION:
>        return type_code1 == UNION_TYPE;
>
> +    case CPTK_IS_UNSIGNED:
> +      return TYPE_UNSIGNED (type1);
> +
>      case CPTK_IS_ASSIGNABLE:
>        return is_xible (MODIFY_EXPR, type1, type2);
>
> @@ -12200,6 +12203,7 @@ finish_trait_expr (location_t loc, cp_trait_kind
> kind, tree type1, tree type2)
>      case CPTK_IS_ENUM:
>      case CPTK_IS_UNION:
>      case CPTK_IS_SAME:
> +    case CPTK_IS_UNSIGNED:
>        break;
>
>      case CPTK_IS_LAYOUT_COMPATIBLE:
> diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> index f343e153e56..20bf8e6cad5 100644
> --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> @@ -146,3 +146,6 @@
>  #if !__has_builtin (__remove_cvref)
>  # error "__has_builtin (__remove_cvref) failed"
>  #endif
> +#if !__has_builtin (__is_unsigned)
> +# error "__has_builtin (__is_unsigned) failed"
> +#endif
> diff --git a/gcc/testsuite/g++.dg/ext/is_unsigned.C
> b/gcc/testsuite/g++.dg/ext/is_unsigned.C
> new file mode 100644
> index 00000000000..02ab9f4d5f2
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ext/is_unsigned.C
> @@ -0,0 +1,46 @@
> +// { dg-do compile { target c++11 } }
> +
> +#include <testsuite_tr1.h>
> +
> +using namespace __gnu_test;
> +
> +#define SA(X) static_assert((X),#X)
> +#define SA_TEST_CATEGORY(TRAIT, X, expect) \
> +  SA(TRAIT(X) == expect);                  \
> +  SA(TRAIT(const X) == expect);            \
> +  SA(TRAIT(volatile X) == expect);         \
> +  SA(TRAIT(const volatile X) == expect)
> +
> +SA_TEST_CATEGORY(__is_unsigned, void, false);
> +
> +SA_TEST_CATEGORY(__is_unsigned, char, (char(-1) > char(0)));
> +SA_TEST_CATEGORY(__is_unsigned, signed char, false);
> +SA_TEST_CATEGORY(__is_unsigned, unsigned char, true);
> +SA_TEST_CATEGORY(__is_unsigned, wchar_t, (wchar_t(-1) > wchar_t(0)));
> +SA_TEST_CATEGORY(__is_unsigned, short, false);
> +SA_TEST_CATEGORY(__is_unsigned, unsigned short, true);
> +SA_TEST_CATEGORY(__is_unsigned, int, false);
> +SA_TEST_CATEGORY(__is_unsigned, unsigned int, true);
> +SA_TEST_CATEGORY(__is_unsigned, long, false);
> +SA_TEST_CATEGORY(__is_unsigned, unsigned long, true);
> +SA_TEST_CATEGORY(__is_unsigned, long long, false);
> +SA_TEST_CATEGORY(__is_unsigned, unsigned long long, true);
>

Please add a check with bool.


> +
> +SA_TEST_CATEGORY(__is_unsigned, float, false);
> +SA_TEST_CATEGORY(__is_unsigned, double, false);
> +SA_TEST_CATEGORY(__is_unsigned, long double, false);
> +
> +#ifndef __STRICT_ANSI__
> +// GNU Extensions.
> +#ifdef __SIZEOF_INT128__
> +SA_TEST_CATEGORY(__is_unsigned, unsigned __int128, true);
> +SA_TEST_CATEGORY(__is_unsigned, __int128, false);
> +#endif
> +
> +#ifdef _GLIBCXX_USE_FLOAT128
> +SA_TEST_CATEGORY(__is_unsigned, __float128, false);
> +#endif
> +#endif
> +
> +// Sanity check.
> +SA_TEST_CATEGORY(__is_unsigned, ClassType, false);
> --
> 2.40.0
>
>