On Wed, Jul 12, 2023 at 3:20 AM Jonathan Wakely <jwak...@redhat.com> wrote:
>
> On Sun, 9 Jul 2023 at 09:50, Ken Matsui via Libstdc++
> <libstd...@gcc.gnu.org> wrote:
> >
> > This patch implements built-in trait for std::is_signed.
> >
> > gcc/cp/ChangeLog:
> >
> > * cp-trait.def: Define __is_signed.
> > * constraint.cc (diagnose_trait_expr): Handle CPTK_IS_SIGNED.
> > * semantics.cc (trait_expr_value): Likewise.
> > (finish_trait_expr): Likewise.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/ext/has-builtin-1.C: Test existence of __is_signed.
> > * g++.dg/ext/is_signed.C: New test.
> > * g++.dg/tm/pr46567.C (__is_signed): Rename to ...
> > (____is_signed): ... this.
> >
> > libstdc++-v3/ChangeLog:
> >
> > * include/ext/numeric_traits.h (__is_signed): Rename to ...
> > (____is_signed): ... this.
>
> Again, please do not use four underscores.
>
> This data member of __numeric_traits_integer could be __signed or
> __is_signed_integer. I think I prefer __signed here, since the
> "integer" part is redundant with __numeric_traits_integer.
>
Thank you for your review. It appears that __signed is a keyword. I
will choose __is_signed_type since we also have __is_signed for
__numeric_traits_floating.
>
>
> > * include/bits/charconv.h: Use ____is_signed instead.
> > * include/bits/locale_facets.tcc: Likewise.
> > * include/bits/uniform_int_dist.h: Likewise.
> >
> > Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
> > ---
> > 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_signed.C | 47 ++++++++++++++++++++
> > gcc/testsuite/g++.dg/tm/pr46567.C | 12 ++---
> > libstdc++-v3/include/bits/charconv.h | 2 +-
> > libstdc++-v3/include/bits/locale_facets.tcc | 6 +--
> > libstdc++-v3/include/bits/uniform_int_dist.h | 4 +-
> > libstdc++-v3/include/ext/numeric_traits.h | 18 ++++----
> > 10 files changed, 79 insertions(+), 21 deletions(-)
> > create mode 100644 gcc/testsuite/g++.dg/ext/is_signed.C
> >
> > diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
> > index 8cf0f2d0974..73fcbfe39e8 100644
> > --- a/gcc/cp/constraint.cc
> > +++ b/gcc/cp/constraint.cc
> > @@ -3751,6 +3751,9 @@ diagnose_trait_expr (tree expr, tree args)
> > case CPTK_IS_UNION:
> > inform (loc, " %qT is not a union", t1);
> > break;
> > + case CPTK_IS_SIGNED:
> > + inform (loc, " %qT is not a signed 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 8b7fece0cc8..576d5528d05 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_SIGNED, "__is_signed", 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 8fb47fd179e..17aad992f96 100644
> > --- a/gcc/cp/semantics.cc
> > +++ b/gcc/cp/semantics.cc
> > @@ -12118,6 +12118,9 @@ trait_expr_value (cp_trait_kind kind, tree type1,
> > tree type2)
> > case CPTK_IS_UNION:
> > return type_code1 == UNION_TYPE;
> >
> > + case CPTK_IS_SIGNED:
> > + return ARITHMETIC_TYPE_P (type1) && TYPE_SIGN (type1) == SIGNED;
> > +
> > case CPTK_IS_ASSIGNABLE:
> > return is_xible (MODIFY_EXPR, type1, type2);
> >
> > @@ -12296,6 +12299,7 @@ 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_SIGNED:
> > 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..a43202d0d59 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_signed)
> > +# error "__has_builtin (__is_signed) failed"
> > +#endif
> > diff --git a/gcc/testsuite/g++.dg/ext/is_signed.C
> > b/gcc/testsuite/g++.dg/ext/is_signed.C
> > new file mode 100644
> > index 00000000000..a04b548105d
> > --- /dev/null
> > +++ b/gcc/testsuite/g++.dg/ext/is_signed.C
> > @@ -0,0 +1,47 @@
> > +// { 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_signed, void, false);
> > +
> > +SA_TEST_CATEGORY(__is_signed, bool, bool(-1) < bool(0));
> > +SA_TEST_CATEGORY(__is_signed, char, char(-1) < char(0));
> > +SA_TEST_CATEGORY(__is_signed, signed char, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned char, false);
> > +SA_TEST_CATEGORY(__is_signed, wchar_t, wchar_t(-1) < wchar_t(0));
> > +SA_TEST_CATEGORY(__is_signed, short, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned short, false);
> > +SA_TEST_CATEGORY(__is_signed, int, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned int, false);
> > +SA_TEST_CATEGORY(__is_signed, long, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned long, false);
> > +SA_TEST_CATEGORY(__is_signed, long long, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned long long, false);
> > +
> > +SA_TEST_CATEGORY(__is_signed, float, true);
> > +SA_TEST_CATEGORY(__is_signed, double, true);
> > +SA_TEST_CATEGORY(__is_signed, long double, true);
> > +
> > +#ifndef __STRICT_ANSI__
> > +// GNU Extensions.
> > +#ifdef __SIZEOF_INT128__
> > +SA_TEST_CATEGORY(__is_signed, __int128, true);
> > +SA_TEST_CATEGORY(__is_signed, unsigned __int128, false);
> > +#endif
> > +
> > +#ifdef _GLIBCXX_USE_FLOAT128
> > +SA_TEST_CATEGORY(__is_signed, __float128, true);
> > +#endif
> > +#endif
> > +
> > +// Sanity check.
> > +SA_TEST_CATEGORY(__is_signed, ClassType, false);
> > diff --git a/gcc/testsuite/g++.dg/tm/pr46567.C
> > b/gcc/testsuite/g++.dg/tm/pr46567.C
> > index 6d791484448..06400fa1178 100644
> > --- a/gcc/testsuite/g++.dg/tm/pr46567.C
> > +++ b/gcc/testsuite/g++.dg/tm/pr46567.C
> > @@ -403,7 +403,7 @@ namespace __gnu_cxx __attribute__ ((__visibility__
> > ("default"))) {
> > {
> > static const _Value __min = (((_Value)(-1) < 0) ? (_Value)1 <<
> > (sizeof(_Value) * 8 - ((_Value)(-1) < 0)) : (_Value)0);
> > static const _Value __max = (((_Value)(-1) < 0) ? (((((_Value)1 <<
> > ((sizeof(_Value) * 8 - ((_Value)(-1) < 0)) - 1)) - 1) << 1) + 1) :
> > ~(_Value)0);
> > - static const bool __is_signed = ((_Value)(-1) < 0);
> > + static const bool ____is_signed = ((_Value)(-1) < 0);
> > static const int __digits = (sizeof(_Value) * 8 - ((_Value)(-1) <
> > 0));
> > };
> > template<typename _Value>
> > @@ -411,21 +411,21 @@ namespace __gnu_cxx __attribute__ ((__visibility__
> > ("default"))) {
> > template<typename _Value>
> > const _Value __numeric_traits_integer<_Value>::__max;
> > template<typename _Value>
> > - const bool __numeric_traits_integer<_Value>::__is_signed;
> > + const bool __numeric_traits_integer<_Value>::____is_signed;
> > template<typename _Value>
> > const int __numeric_traits_integer<_Value>::__digits;
> > template<typename _Value>
> > struct __numeric_traits_floating
> > {
> > static const int __max_digits10 = (2 + (std::__are_same<_Value,
> > float>::__value ? 24 : std::__are_same<_Value, double>::__value ? 53 : 64)
> > * 3010 / 10000);
> > - static const bool __is_signed = true;
> > + static const bool ____is_signed = true;
> > static const int __digits10 = (std::__are_same<_Value,
> > float>::__value ? 6 : std::__are_same<_Value, double>::__value ? 15 : 18);
> > static const int __max_exponent10 = (std::__are_same<_Value,
> > float>::__value ? 38 : std::__are_same<_Value, double>::__value ? 308 :
> > 4932);
> > };
> > template<typename _Value>
> > const int __numeric_traits_floating<_Value>::__max_digits10;
> > template<typename _Value>
> > - const bool __numeric_traits_floating<_Value>::__is_signed;
> > + const bool __numeric_traits_floating<_Value>::____is_signed;
> > template<typename _Value>
> > const int __numeric_traits_floating<_Value>::__digits10;
> > template<typename _Value>
> > @@ -1513,8 +1513,8 @@ namespace std __attribute__ ((__visibility__
> > ("default"))) {
> > typedef typename iterator_traits<_II2>::value_type _ValueType2;
> > const bool __simple =
> > (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
> > - && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
> > - && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
> > + && !__gnu_cxx::__numeric_traits<_ValueType1>::____is_signed
> > + && !__gnu_cxx::__numeric_traits<_ValueType2>::____is_signed
> > && __is_pointer<_II1>::__value
> > && __is_pointer<_II2>::__value);
> > return std::__lexicographical_compare<__simple>::__lc(__first1,
> > __last1,
> > diff --git a/libstdc++-v3/include/bits/charconv.h
> > b/libstdc++-v3/include/bits/charconv.h
> > index 20da8303f7a..c6a4c993c17 100644
> > --- a/libstdc++-v3/include/bits/charconv.h
> > +++ b/libstdc++-v3/include/bits/charconv.h
> > @@ -46,7 +46,7 @@ namespace __detail
> > // This accepts 128-bit integers even in strict mode.
> > template<typename _Tp>
> > constexpr bool __integer_to_chars_is_unsigned
> > - = ! __gnu_cxx::__int_traits<_Tp>::__is_signed;
> > + = ! __gnu_cxx::__int_traits<_Tp>::____is_signed;
> > #endif
> >
> > // Generic implementation for arbitrary bases.
> > diff --git a/libstdc++-v3/include/bits/locale_facets.tcc
> > b/libstdc++-v3/include/bits/locale_facets.tcc
> > index 6bfff7d6289..0e62bc89397 100644
> > --- a/libstdc++-v3/include/bits/locale_facets.tcc
> > +++ b/libstdc++-v3/include/bits/locale_facets.tcc
> > @@ -470,7 +470,7 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
> > bool __testfail = false;
> > bool __testoverflow = false;
> > const __unsigned_type __max =
> > - (__negative && __num_traits::__is_signed)
> > + (__negative && __num_traits::____is_signed)
> > ? -static_cast<__unsigned_type>(__num_traits::__min)
> > : __num_traits::__max;
> > const __unsigned_type __smax = __max / __base;
> > @@ -573,7 +573,7 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
> > }
> > else if (__testoverflow)
> > {
> > - if (__negative && __num_traits::__is_signed)
> > + if (__negative && __num_traits::____is_signed)
> > __v = __num_traits::__min;
> > else
> > __v = __num_traits::__max;
> > @@ -914,7 +914,7 @@ _GLIBCXX_BEGIN_NAMESPACE_LDBL
> > if (__v >= 0)
> > {
> > if (bool(__flags & ios_base::showpos)
> > - && __gnu_cxx::__numeric_traits<_ValueT>::__is_signed)
> > + && __gnu_cxx::__numeric_traits<_ValueT>::____is_signed)
> > *--__cs = __lit[__num_base::_S_oplus], ++__len;
> > }
> > else
> > diff --git a/libstdc++-v3/include/bits/uniform_int_dist.h
> > b/libstdc++-v3/include/bits/uniform_int_dist.h
> > index 7ccf930a6d4..b8cfa3c1c71 100644
> > --- a/libstdc++-v3/include/bits/uniform_int_dist.h
> > +++ b/libstdc++-v3/include/bits/uniform_int_dist.h
> > @@ -258,8 +258,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > {
> > using _Up_traits = __gnu_cxx::__int_traits<_Up>;
> > using _Wp_traits = __gnu_cxx::__int_traits<_Wp>;
> > - static_assert(!_Up_traits::__is_signed, "U must be unsigned");
> > - static_assert(!_Wp_traits::__is_signed, "W must be unsigned");
> > + static_assert(!_Up_traits::____is_signed, "U must be unsigned");
> > + static_assert(!_Wp_traits::____is_signed, "W must be unsigned");
> > static_assert(_Wp_traits::__digits == (2 * _Up_traits::__digits),
> > "W must be twice as wide as U");
> >
> > diff --git a/libstdc++-v3/include/ext/numeric_traits.h
> > b/libstdc++-v3/include/ext/numeric_traits.h
> > index dcbc2d12927..ce7341be785 100644
> > --- a/libstdc++-v3/include/ext/numeric_traits.h
> > +++ b/libstdc++-v3/include/ext/numeric_traits.h
> > @@ -67,15 +67,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >
> > // NB: these two are also available in std::numeric_limits as compile
> > // time constants, but <limits> is big and we can avoid including it.
> > - static const bool __is_signed = (_Value)(-1) < 0;
> > + static const bool ____is_signed = (_Value)(-1) < 0;
> > static const int __digits
> > - = __is_integer_nonstrict<_Value>::__width - __is_signed;
> > + = __is_integer_nonstrict<_Value>::__width - ____is_signed;
> >
> > // The initializers must be constants so that __max and __min are
> > too.
> > - static const _Value __max = __is_signed
> > + static const _Value __max = ____is_signed
> > ? (((((_Value)1 << (__digits - 1)) - 1) << 1) + 1)
> > : ~(_Value)0;
> > - static const _Value __min = __is_signed ? -__max - 1 : (_Value)0;
> > + static const _Value __min = ____is_signed ? -__max - 1 : (_Value)0;
> > };
> >
> > template<typename _Value>
> > @@ -85,7 +85,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > const _Value __numeric_traits_integer<_Value>::__max;
> >
> > template<typename _Value>
> > - const bool __numeric_traits_integer<_Value>::__is_signed;
> > + const bool __numeric_traits_integer<_Value>::____is_signed;
> >
> > template<typename _Value>
> > const int __numeric_traits_integer<_Value>::__digits;
> > @@ -161,7 +161,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > static const int __max_digits10 = __glibcxx_max_digits10(_Value);
> >
> > // See above comment...
> > - static const bool __is_signed = true;
> > + static const bool ____is_signed = true;
> > static const int __digits10 = __glibcxx_digits10(_Value);
> > static const int __max_exponent10 = __glibcxx_max_exponent10(_Value);
> > };
> > @@ -170,7 +170,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > const int __numeric_traits_floating<_Value>::__max_digits10;
> >
> > template<typename _Value>
> > - const bool __numeric_traits_floating<_Value>::__is_signed;
> > + const bool __numeric_traits_floating<_Value>::____is_signed;
> >
> > template<typename _Value>
> > const int __numeric_traits_floating<_Value>::__digits10;
> > @@ -210,7 +210,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > struct __numeric_traits_floating<__ibm128>
> > {
> > static const int __max_digits10 = 33;
> > - static const bool __is_signed = true;
> > + static const bool ____is_signed = true;
> > static const int __digits10 = 31;
> > static const int __max_exponent10 = 308;
> > };
> > @@ -224,7 +224,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > struct __numeric_traits_floating<__ieee128>
> > {
> > static const int __max_digits10 = 36;
> > - static const bool __is_signed = true;
> > + static const bool ____is_signed = true;
> > static const int __digits10 = 33;
> > static const int __max_exponent10 = 4932;
> > };
> > --
> > 2.41.0
> >
>
