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Diffstat (limited to 'm4/stdbool.m4')
| -rw-r--r-- | m4/stdbool.m4 | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/m4/stdbool.m4 b/m4/stdbool.m4 new file mode 100644 index 0000000..3169779 --- /dev/null +++ b/m4/stdbool.m4 @@ -0,0 +1,122 @@ +# Check for stdbool.h that conforms to C99. + +dnl Copyright (C) 2002-2006, 2009-2021 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. + +#serial 8 + +# Prepare for substituting <stdbool.h> if it is not supported. + +AC_DEFUN([AM_STDBOOL_H], +[ + AC_REQUIRE([AC_CHECK_HEADER_STDBOOL]) + AC_REQUIRE([AC_CANONICAL_HOST]) + + dnl On some platforms, <stdbool.h> does not exist or does not conform to C99. + dnl On Solaris 10 with CC=cc CXX=CC, <stdbool.h> exists but is not usable + dnl in C++ mode (and no <cstdbool> exists). In this case, we use our + dnl replacement, also in C mode (for binary compatibility between C and C++). + if test "$ac_cv_header_stdbool_h" = yes; then + case "$host_os" in + solaris*) + if test -z "$GCC"; then + STDBOOL_H='stdbool.h' + else + STDBOOL_H='' + fi + ;; + *) + STDBOOL_H='' + ;; + esac + else + STDBOOL_H='stdbool.h' + fi + AC_SUBST([STDBOOL_H]) + AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$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 version of the macro is needed in autoconf <= 2.68. + +AC_DEFUN([AC_CHECK_HEADER_STDBOOL], + [AC_CACHE_CHECK([for stdbool.h that conforms to C99], + [ac_cv_header_stdbool_h], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[ + #include <stdbool.h> + + #ifdef __cplusplus + typedef bool Bool; + #else + typedef _Bool Bool; + #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 + #endif + + #ifndef __bool_true_false_are_defined + "error: __bool_true_false_are_defined is not defined" + #endif + + struct s { Bool s: 1; Bool t; bool u: 1; bool v; } 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]; + /* See body of main program for 'e'. */ + 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 }; + /* The following fails for + HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */ + 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]; + /* Catch a bug in an HP-UX C compiler. See + https://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html + https://lists.gnu.org/r/bug-coreutils/2005-11/msg00161.html + */ + Bool q = true; + Bool *pq = &q; + bool *qq = &q; + ]], + [[ + bool e = &s; + *pq |= q; *pq |= ! q; + *qq |= q; *qq |= ! 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 + !qq); + ]])], + [ac_cv_header_stdbool_h=yes], + [ac_cv_header_stdbool_h=no])]) + AC_CHECK_TYPES([_Bool]) +]) |