tree 70ffd95db19c46bfcf465081cb7f842c29d1593a
parent 973b932e2da39f80ecbd25b8f0973c5fd82fafa3
author Liu Hao <lh_mouse@126.com> 1623642869 +0800
committer Liu Hao <lh_mouse@126.com> 1623670033 +0800

headers/locale: Make result of `localeconv()` accord to GCC's `-funsigned-char` option

This enables the old behavior when `-funsigned-char` is specified.

The `selectany` attribute is assumed to be supported since GCC 4.2, and
probably by Clang as well.

This test program should print 127 when `char` is signed and 255 when it
is unsigned:

  #include <stdio.h>
  #include <locale.h>

  int main(void)
    {
      struct lconv* lc = localeconv();
      printf("frac_digits = %d\n", lc->frac_digits);
    }

Reference: https://sourceforge.net/p/mingw-w64/mailman/message/37300502/
Reference: https://gcc.gnu.org/onlinedocs/gcc-4.2.4/gcc/Variable-Attributes.html
Signed-off-by: Liu Hao <lh_mouse@126.com>