On Sunday, 2 November 2025, Jason Merrill <[email protected]> wrote:
> Tested x86_64-pc-linux-gnu, OK for trunk?
>
OK, thanks. I don't see any other reason that we were testing those cases,
so agree we can (and should) drop them from the tests.
>
> -- 8< --
>
> In r15-3499 I added attributes to _Ios_Openmode to avoid -Wswitch false
> positives; let's do the same for the other enums in ios_base.
>
> It also seems to me that with these attributes, the tests don't need to
> include the end/max/min cases.
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/ios_base.h: Add attribs to _Ios_Fmtflags,
> _Ios_Iostate, _ios_seekdir.
> * testsuite/27_io/ios_base/types/fmtflags/case_label.cc: Remove
> unneeded cases.
> * testsuite/27_io/ios_base/types/iostate/case_label.cc: Likewise.
> * testsuite/27_io/ios_base/types/openmode/case_label.cc: Likewise.
> * testsuite/27_io/ios_base/types/seekdir/case_label.cc: Likewise.
> ---
> libstdc++-v3/include/bits/ios_base.h | 18 +++++++++---------
> .../ios_base/types/fmtflags/case_label.cc | 6 ------
> .../27_io/ios_base/types/iostate/case_label.cc | 6 ------
> .../ios_base/types/openmode/case_label.cc | 6 ------
> .../27_io/ios_base/types/seekdir/case_label.cc | 2 --
> 5 files changed, 9 insertions(+), 29 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/ios_base.h
> b/libstdc++-v3/include/bits/ios_base.h
> index b94b2cddcd9..adc2982059a 100644
> --- a/libstdc++-v3/include/bits/ios_base.h
> +++ b/libstdc++-v3/include/bits/ios_base.h
> @@ -56,7 +56,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> // as permitted (but not required) in the standard, in order to provide
> // better type safety in iostream calls. A side effect is that in C++98
> // expressions involving them are not compile-time constants.
> - enum _Ios_Fmtflags
> + enum __attribute__((__flag_enum__)) _Ios_Fmtflags
> {
> _S_boolalpha = 1L << 0,
> _S_dec = 1L << 1,
> @@ -76,9 +76,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _S_adjustfield = _S_left | _S_right | _S_internal,
> _S_basefield = _S_dec | _S_oct | _S_hex,
> _S_floatfield = _S_scientific | _S_fixed,
> - _S_ios_fmtflags_end = 1L << 16,
> - _S_ios_fmtflags_max = __INT_MAX__,
> - _S_ios_fmtflags_min = ~__INT_MAX__
> + _S_ios_fmtflags_end __attribute__((__unused__)) = 1L << 16,
> + _S_ios_fmtflags_max __attribute__((__unused__)) = __INT_MAX__,
> + _S_ios_fmtflags_min __attribute__((__unused__)) = ~__INT_MAX__
> };
>
> _GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
> @@ -176,15 +176,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> { return __a = __a ^ __b; }
>
>
> - enum _Ios_Iostate
> + enum __attribute__((__flag_enum__)) _Ios_Iostate
> {
> _S_goodbit = 0,
> _S_badbit = 1L << 0,
> _S_eofbit = 1L << 1,
> _S_failbit = 1L << 2,
> - _S_ios_iostate_end = 1L << 16,
> - _S_ios_iostate_max = __INT_MAX__,
> - _S_ios_iostate_min = ~__INT_MAX__
> + _S_ios_iostate_end __attribute__((__unused__)) = 1L << 16,
> + _S_ios_iostate_max __attribute__((__unused__)) = __INT_MAX__,
> + _S_ios_iostate_min __attribute__((__unused__)) = ~__INT_MAX__
> };
>
> _GLIBCXX_NODISCARD _GLIBCXX_CONSTEXPR
> @@ -228,7 +228,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> _S_beg = 0,
> _S_cur = _GLIBCXX_STDIO_SEEK_CUR,
> _S_end = _GLIBCXX_STDIO_SEEK_END,
> - _S_ios_seekdir_end = 1L << 16
> + _S_ios_seekdir_end __attribute__((__unused__)) = 1L << 16
> };
>
> #if __cplusplus >= 201103L
> diff --git
> a/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/case_label.cc
> b/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/case_label.cc
> index c72e00f87b5..6f0390b6cff 100644
> --- a/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/case_label.cc
> +++ b/libstdc++-v3/testsuite/27_io/ios_base/types/fmtflags/case_label.cc
> @@ -68,12 +68,6 @@ case_labels(bitmask_type b)
> break;
> case std::ios_base::floatfield:
> break;
> - case std::_S_ios_fmtflags_end:
> - break;
> - case __INT_MAX__:
> - break;
> - case ~__INT_MAX__:
> - break;
> }
> using underlying_type = std::underlying_type<bitmask_type>::type;
> static_assert( sizeof(underlying_type) == sizeof(int),
> diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/case_label.cc
> b/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/case_label.cc
> index 6a1dd90f67b..410f7464283 100644
> --- a/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/case_label.cc
> +++ b/libstdc++-v3/testsuite/27_io/ios_base/types/iostate/case_label.cc
> @@ -40,12 +40,6 @@ case_labels(bitmask_type b)
> break;
> case std::ios_base::failbit:
> break;
> - case std::_S_ios_iostate_end:
> - break;
> - case __INT_MAX__:
> - break;
> - case ~__INT_MAX__:
> - break;
> }
> using underlying_type = std::underlying_type<bitmask_type>::type;
> static_assert( sizeof(underlying_type) == sizeof(int),
> diff --git
> a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
> b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
> index e132070bf48..44b84a9821f 100644
> --- a/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
> +++ b/libstdc++-v3/testsuite/27_io/ios_base/types/openmode/case_label.cc
> @@ -48,12 +48,6 @@ case_labels(bitmask_type b)
> case std::ios_base::noreplace:
> break;
> #endif
> - case std::_S_ios_openmode_end:
> - break;
> - case __INT_MAX__:
> - break;
> - case ~__INT_MAX__:
> - break;
> }
> using underlying_type = std::underlying_type<bitmask_type>::type;
> static_assert( sizeof(underlying_type) == sizeof(int),
> diff --git a/libstdc++-v3/testsuite/27_io/ios_base/types/seekdir/case_label.cc
> b/libstdc++-v3/testsuite/27_io/ios_base/types/seekdir/case_label.cc
> index c7b9817932d..2dd1560339d 100644
> --- a/libstdc++-v3/testsuite/27_io/ios_base/types/seekdir/case_label.cc
> +++ b/libstdc++-v3/testsuite/27_io/ios_base/types/seekdir/case_label.cc
> @@ -38,7 +38,5 @@ case_labels(test_type b)
> break;
> case std::ios_base::end:
> break;
> - case std::_S_ios_fmtflags_end:
> - break;
> }
> }
>
> base-commit: 2be505ace7e5e29a29ab53025762cf1a100a6d76
> --
> 2.51.0
>
>
