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Diffstat (limited to 'gnulib/m4/stdbool.m4')
| -rw-r--r-- | gnulib/m4/stdbool.m4 | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/gnulib/m4/stdbool.m4 b/gnulib/m4/stdbool.m4 new file mode 100644 index 0000000..2204ecd --- /dev/null +++ b/gnulib/m4/stdbool.m4 @@ -0,0 +1,115 @@ +# Check for stdbool.h that conforms to C99. + +dnl Copyright (C) 2002-2006 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +# Prepare for substituting <stdbool.h> if it is not supported. + +AC_DEFUN([AM_STDBOOL_H], +[ + AC_REQUIRE([AC_HEADER_STDBOOL]) + + # Define two additional variables used in the Makefile substitution. + + if test "$ac_cv_header_stdbool_h" = yes; then + STDBOOL_H='' + else + STDBOOL_H='stdbool.h' + fi + AC_SUBST([STDBOOL_H]) + + if test "$ac_cv_type__Bool" = yes; then + HAVE__BOOL=1 + else + HAVE__BOOL=0 + fi + AC_SUBST([HAVE__BOOL]) +]) + +# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future. +AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H]) + +# This macro is only needed in autoconf <= 2.59. Newer versions of autoconf +# have this macro built-in. + +AC_DEFUN([AC_HEADER_STDBOOL], + [AC_CACHE_CHECK([for stdbool.h that conforms to C99], + [ac_cv_header_stdbool_h], + [AC_TRY_COMPILE( + [ + #include <stdbool.h> + #ifndef bool + "error: bool is not defined" + #endif + #ifndef false + "error: false is not defined" + #endif + #if false + "error: false is not 0" + #endif + #ifndef true + "error: true is not defined" + #endif + #if true != 1 + "error: true is not 1" + #endif + #ifndef __bool_true_false_are_defined + "error: __bool_true_false_are_defined is not defined" + #endif + + struct s { _Bool s: 1; _Bool t; } s; + + char a[true == 1 ? 1 : -1]; + char b[false == 0 ? 1 : -1]; + char c[__bool_true_false_are_defined == 1 ? 1 : -1]; + char d[(bool) 0.5 == true ? 1 : -1]; + bool e = &s; + char f[(_Bool) 0.0 == false ? 1 : -1]; + char g[true]; + char h[sizeof (_Bool)]; + char i[sizeof s.t]; + enum { j = false, k = true, l = false * true, m = true * 256 }; + _Bool n[m]; + char o[sizeof n == m * sizeof n[0] ? 1 : -1]; + char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1]; + #if defined __xlc__ || defined __GNUC__ + /* Catch a bug in IBM AIX xlc compiler version 6.0.0.0 + reported by James Lemley on 2005-10-05; see + http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html + This test is not quite right, since xlc is allowed to + reject this program, as the initializer for xlcbug is + not one of the forms that C requires support for. + However, doing the test right would require a run-time + test, and that would make cross-compilation harder. + Let us hope that IBM fixes the xlc bug, and also adds + support for this kind of constant expression. In the + meantime, this test will reject xlc, which is OK, since + our stdbool.h substitute should suffice. We also test + this with GCC, where it should work, to detect more + quickly whether someone messes up the test in the + future. */ + char digs[] = "0123456789"; + int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : -1); + #endif + /* Catch a bug in an HP-UX C compiler. See + http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html + http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html + */ + _Bool q = true; + _Bool *pq = &q; + ], + [ + *pq |= q; + *pq |= ! q; + /* Refer to every declared value, to avoid compiler optimizations. */ + return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l + + !m + !n + !o + !p + !q + !pq); + ], + [ac_cv_header_stdbool_h=yes], + [ac_cv_header_stdbool_h=no])]) + AC_CHECK_TYPES([_Bool]) + if test $ac_cv_header_stdbool_h = yes; then + AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.]) + fi]) |