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Diffstat (limited to 'gnulib_m4/stdbool.m4')
| -rw-r--r-- | gnulib_m4/stdbool.m4 | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/gnulib_m4/stdbool.m4 b/gnulib_m4/stdbool.m4 new file mode 100644 index 0000000..d4d54d0 --- /dev/null +++ b/gnulib_m4/stdbool.m4 @@ -0,0 +1,118 @@ +# Check for stdbool.h that conforms to C99. + +dnl Copyright (C) 2002-2006, 2009-2023 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 10 + +# Prepare for substituting <stdbool.h> if it is not supported. + +AC_DEFUN([gl_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 "$GCC"; then + GL_GENERATE_STDBOOL_H=true + else + GL_GENERATE_STDBOOL_H=false + fi + ;; + *) + GL_GENERATE_STDBOOL_H=false + ;; + esac + else + GL_GENERATE_STDBOOL_H=true + fi + + if test "$ac_cv_type__Bool" = yes; then + HAVE__BOOL=1 + else + HAVE__BOOL=0 + fi + AC_SUBST([HAVE__BOOL]) +]) + +m4_version_prereq([2.72], [], [ + +AC_DEFUN([AC_CHECK_HEADER_STDBOOL], + [AC_CHECK_TYPES([_Bool]) + AC_CACHE_CHECK([for stdbool.h that conforms to C99 or later], + [ac_cv_header_stdbool_h], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stdbool.h> + + /* "true" and "false" should be usable in #if expressions and + integer constant expressions, and "bool" should be a valid + type name. + + Although C99 requires bool, true, and false to be macros, + C23 and C++11 overrule that, so do not test for that. + Although C99 requires __bool_true_false_are_defined and + _Bool, C23 says they are obsolescent, so do not require + them. */ + + #if !true + #error "'true' is not true" + #endif + #if true != 1 + #error "'true' is not equal to 1" + #endif + char b[true == 1 ? 1 : -1]; + char c[true]; + + #if false + #error "'false' is not false" + #endif + #if false != 0 + #error "'false' is not equal to 0" + #endif + char d[false == 0 ? 1 : -1]; + + enum { e = false, f = true, g = false * true, h = true * 256 }; + + char i[(bool) 0.5 == true ? 1 : -1]; + char j[(bool) 0.0 == false ? 1 : -1]; + char k[sizeof (bool) > 0 ? 1 : -1]; + + struct sb { bool s: 1; bool t; } s; + char l[sizeof s.t > 0 ? 1 : -1]; + + /* The following fails for + HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */ + bool m[h]; + char n[sizeof m == h * sizeof m[0] ? 1 : -1]; + char o[-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 p = true; + bool *pp = &p; + ]], + [[ + bool ps = &s; + *pp |= p; + *pp |= ! p; + + /* Refer to every declared value, so they cannot be + discarded as unused. */ + return (!b + !c + !d + !e + !f + !g + !h + !i + !j + !k + + !l + !m + !n + !o + !p + !pp + !ps); + ]])], + [ac_cv_header_stdbool_h=yes], + [ac_cv_header_stdbool_h=no])]) +])# AC_CHECK_HEADER_STDBOOL + +]) # m4_version_prereq 2.72 |