[PATCH] define [U]LLONG_{MIN,MAX} for C++11

[Richard Smith]

On Sat, Oct 26, 2013 at 4:16 PM, JF Bastien <jfb at google.com> wrote:

> I couldn't find a pre-existing test for this file, how about I add the
> following as tools/clang/test/Headers/limits.cpp :
>

SGTM, go ahead, thanks!


> // RUN: %clang_cc1 -ffreestanding -fsyntax-only -verify %s
> // RUN: %clang_cc1 -fno-signed-char -ffreestanding -fsyntax-only -verify %s
> // RUN: %clang_cc1 -std=c++11 -ffreestanding -fsyntax-only -verify %s
> // expected-no-diagnostics
>
> #include <limits.h>
>
> _Static_assert(SCHAR_MAX == -(SCHAR_MIN+1), "");
> _Static_assert(SHRT_MAX == -(SHRT_MIN+1), "");
> _Static_assert(INT_MAX == -(INT_MIN+1), "");
> _Static_assert(LONG_MAX == -(LONG_MIN+1L), "");
>
> _Static_assert(SCHAR_MIN == -SCHAR_MAX-1, "");
> _Static_assert(SHRT_MIN == -SHRT_MAX-1, "");
> _Static_assert(INT_MIN == -INT_MAX-1, "");
> _Static_assert(LONG_MIN == -LONG_MAX-1L, "");
>

It'd be nice to test that the values are actually correct, as well as that
they are in matching pairs. Something like:

(unsigned char)SCHAR_MIN == (unsigned char)SCHAR_MAX + 1

... should do the trick.


> _Static_assert(UCHAR_MAX == (unsigned char)~0ULL, "");
> _Static_assert(USHRT_MAX == (unsigned short)~0ULL, "");
> _Static_assert(UINT_MAX == (unsigned int)~0ULL, "");
> _Static_assert(ULONG_MAX == (unsigned long)~0ULL, "");
>
> _Static_assert(MB_LEN_MAX >= 1, "");
>
> _Static_assert(CHAR_BIT >= 8, "");
>
> const bool char_is_signed = (char)-1 < (char)0;
> _Static_assert(CHAR_MIN == (char_is_signed ? -CHAR_MAX-1 : 0), "");
> _Static_assert(CHAR_MAX == (char_is_signed ? -(CHAR_MIN+1) : (char)~0ULL),
> "");
>
> #if __STDC_VERSION__ >= 199901 || __cplusplus >= 201103L
> _Static_assert(LLONG_MAX == -(LLONG_MIN+1LL), "");
> _Static_assert(LLONG_MIN == -LLONG_MAX-1LL, "");
> _Static_assert(ULLONG_MAX == (unsigned long long)~0ULL, "");
>

Maybe:

#else

int LLONG_MIN, LLONG_MAX, ULLONG_MAX; // not defined


> #endif
>
>
> On Fri, Oct 25, 2013 at 3:43 PM, Richard Smith <richard at metafoo.co.uk>
> wrote:
> > Please add a test for this. Otherwise LGTM.
> >
> > On 22 Oct 2013 16:02, "JF Bastien" <jfb at google.com> wrote:
> >>
> >> C99 has LLONG_MIN, LLONG_MAX, ULLONG_MAX and so does C++11. Teach
> clang's
> >> limits.h about it.
> >>
> >> diff --git a/lib/Headers/limits.h b/lib/Headers/limits.h
> >> index ecd09a4..91bd404 100644
> >> --- a/lib/Headers/limits.h
> >> +++ b/lib/Headers/limits.h
> >> @@ -87,8 +87,10 @@
> >>  #define CHAR_MAX __SCHAR_MAX__
> >>  #endif
> >>
> >> -/* C99 5.2.4.2.1: Added long long. */
> >> -#if __STDC_VERSION__ >= 199901
> >> +/* C99 5.2.4.2.1: Added long long.
> >> +   C++11 18.3.3.2: same contents as the Standard C Library header
> >> <limits.h>.
> >> + */
> >> +#if __STDC_VERSION__ >= 199901 || __cplusplus >= 201103L
> >>
> >>  #undef  LLONG_MIN
> >>  #undef  LLONG_MAX
> >>
> >>
> >> _______________________________________________
> >> cfe-commits mailing list
> >> cfe-commits at cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
> >>
> >
>
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