Annotation of embedaddon/libiconv/srcm4/stdbool.m4, revision 1.1
1.1 ! misho 1: # Check for stdbool.h that conforms to C99.
! 2:
! 3: dnl Copyright (C) 2002-2006, 2009 Free Software Foundation, Inc.
! 4: dnl This file is free software; the Free Software Foundation
! 5: dnl gives unlimited permission to copy and/or distribute it,
! 6: dnl with or without modifications, as long as this notice is preserved.
! 7:
! 8: # Prepare for substituting <stdbool.h> if it is not supported.
! 9:
! 10: AC_DEFUN([AM_STDBOOL_H],
! 11: [
! 12: AC_REQUIRE([AC_HEADER_STDBOOL])
! 13:
! 14: # Define two additional variables used in the Makefile substitution.
! 15:
! 16: if test "$ac_cv_header_stdbool_h" = yes; then
! 17: STDBOOL_H=''
! 18: else
! 19: STDBOOL_H='stdbool.h'
! 20: fi
! 21: AC_SUBST([STDBOOL_H])
! 22:
! 23: if test "$ac_cv_type__Bool" = yes; then
! 24: HAVE__BOOL=1
! 25: else
! 26: HAVE__BOOL=0
! 27: fi
! 28: AC_SUBST([HAVE__BOOL])
! 29: ])
! 30:
! 31: # AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
! 32: AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
! 33:
! 34: # This macro is only needed in autoconf <= 2.59. Newer versions of autoconf
! 35: # have this macro built-in.
! 36:
! 37: AC_DEFUN([AC_HEADER_STDBOOL],
! 38: [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
! 39: [ac_cv_header_stdbool_h],
! 40: [AC_TRY_COMPILE(
! 41: [
! 42: #include <stdbool.h>
! 43: #ifndef bool
! 44: "error: bool is not defined"
! 45: #endif
! 46: #ifndef false
! 47: "error: false is not defined"
! 48: #endif
! 49: #if false
! 50: "error: false is not 0"
! 51: #endif
! 52: #ifndef true
! 53: "error: true is not defined"
! 54: #endif
! 55: #if true != 1
! 56: "error: true is not 1"
! 57: #endif
! 58: #ifndef __bool_true_false_are_defined
! 59: "error: __bool_true_false_are_defined is not defined"
! 60: #endif
! 61:
! 62: struct s { _Bool s: 1; _Bool t; } s;
! 63:
! 64: char a[true == 1 ? 1 : -1];
! 65: char b[false == 0 ? 1 : -1];
! 66: char c[__bool_true_false_are_defined == 1 ? 1 : -1];
! 67: char d[(bool) 0.5 == true ? 1 : -1];
! 68: bool e = &s;
! 69: char f[(_Bool) 0.0 == false ? 1 : -1];
! 70: char g[true];
! 71: char h[sizeof (_Bool)];
! 72: char i[sizeof s.t];
! 73: enum { j = false, k = true, l = false * true, m = true * 256 };
! 74: _Bool n[m];
! 75: char o[sizeof n == m * sizeof n[0] ? 1 : -1];
! 76: char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
! 77: #if defined __xlc__ || defined __GNUC__
! 78: /* Catch a bug in IBM AIX xlc compiler version 6.0.0.0
! 79: reported by James Lemley on 2005-10-05; see
! 80: http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
! 81: This test is not quite right, since xlc is allowed to
! 82: reject this program, as the initializer for xlcbug is
! 83: not one of the forms that C requires support for.
! 84: However, doing the test right would require a run-time
! 85: test, and that would make cross-compilation harder.
! 86: Let us hope that IBM fixes the xlc bug, and also adds
! 87: support for this kind of constant expression. In the
! 88: meantime, this test will reject xlc, which is OK, since
! 89: our stdbool.h substitute should suffice. We also test
! 90: this with GCC, where it should work, to detect more
! 91: quickly whether someone messes up the test in the
! 92: future. */
! 93: char digs[] = "0123456789";
! 94: int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : -1);
! 95: #endif
! 96: /* Catch a bug in an HP-UX C compiler. See
! 97: http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
! 98: http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
! 99: */
! 100: _Bool q = true;
! 101: _Bool *pq = &q;
! 102: ],
! 103: [
! 104: *pq |= q;
! 105: *pq |= ! q;
! 106: /* Refer to every declared value, to avoid compiler optimizations. */
! 107: return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
! 108: + !m + !n + !o + !p + !q + !pq);
! 109: ],
! 110: [ac_cv_header_stdbool_h=yes],
! 111: [ac_cv_header_stdbool_h=no])])
! 112: AC_CHECK_TYPES([_Bool])
! 113: if test $ac_cv_header_stdbool_h = yes; then
! 114: AC_DEFINE([HAVE_STDBOOL_H], [1], [Define to 1 if stdbool.h conforms to C99.])
! 115: fi])
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