[libmicrohttpd] 12/12: mhd_bool.m4: new autoconf macro that supports C23

[gnunet]

This is an automated email from the git hooks/post-receive script.

karlson2k pushed a commit to branch master
in repository libmicrohttpd.

commit 3a93f07d22eb8af286c46c9a07e4ad4ba052196e
Author: Evgeny Grin (Karlson2k) <k2k@narod.ru>
AuthorDate: Sun Apr 28 16:32:15 2024 +0200

    mhd_bool.m4: new autoconf macro that supports C23
    
    The macro should works faster in the most common scenarios
---
 configure.ac   |  97 +----------------------------------------
 m4/mhd_bool.m4 | 135 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+), 96 deletions(-)

diff --git a/configure.ac b/configure.ac
index 16fcbfab..424ec8a8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -760,102 +760,7 @@ AS_VAR_IF([enable_linker_hardening],["yes"],
   ]
 )
 
-
-AH_TEMPLATE([[HAVE_STDBOOL_H]], [Define to 1 i][f you have the <stdbool.h> 
header file and <stdbool.h> defines 'bool' type.])
-AH_TEMPLATE([[HAVE_BUILTIN_TYPE_BOOL]], [Define to 1 i][f you have the real 
boolean type.])
-AH_TEMPLATE([[bool]], [Define to type name which will be used as boolean 
type.])
-AC_CHECK_HEADER([stdbool.h],
-  [
-   AC_CHECK_TYPE([bool],
-     [
-      AC_DEFINE([[HAVE_STDBOOL_H]], [[1]])
-      AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]], [[1]])
-     ],
-     [
-      AC_MSG_WARN([[Header <stdbool.h> is present, but "bool" type cannot be 
detected. Check compiler flags.]])
-      AC_DEFINE([[bool]], [[int]])
-     ], [
-#include <stdbool.h>
-        ]
-   )
-  ],
-  [
-   AC_CHECK_TYPE([bool],
-     [AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]], [[1]])],
-     [
-      AC_CHECK_TYPE([_Bool],
-        [
-         AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]], [[1]])
-         AC_DEFINE([[bool]], [[_Bool]])
-        ],
-        [
-         AC_DEFINE([[bool]], [[int]])
-        ], []
-      )
-     ], []
-   )
-  ],
-  [AC_INCLUDES_DEFAULT]
-)
-
-AC_CACHE_CHECK([[whether "true" is defined or builtin]], 
[[mhd_cv_macro_true_defined]],
-  [AC_COMPILE_IFELSE(
-     [AC_LANG_PROGRAM(
-        [[
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#endif
-        ]], [[
-#if defined(true)
-    /* dummy */
-#else
-    (void)true;
-#endif
-        ]])
-     ], [[mhd_cv_macro_true_defined='yes']], 
[[mhd_cv_macro_true_defined='no']])
-  ])
-AS_VAR_IF([[mhd_cv_macro_true_defined]], [["yes"]], [[:]],
-  [AC_DEFINE([[true]],[[(!0)]], [Define to value interpreted by compiler as 
boolean "true", if "true" is not defined by system headers.])])
-
-AC_CACHE_CHECK([[whether "false" is defined or builtin]], 
[[mhd_cv_macro_false_defined]],
-  [AC_COMPILE_IFELSE(
-     [AC_LANG_PROGRAM(
-        [[
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#endif
-        ]], [[
-#if !defined(false)
-    (void)false;
-#else
-    /* dummy */
-#endif
-        ]])
-     ], [[mhd_cv_macro_false_defined='yes']], 
[[mhd_cv_macro_false_defined='no']])
-  ])
-AS_VAR_IF([[mhd_cv_macro_false_defined]], [["yes"]], [[:]],
-  [AC_DEFINE([[false]],[[0]], [Define to value interpreted by compiler as 
boolean "false", if "false" is not defined by system headers.])])
-
-AC_CACHE_CHECK([[whether "true" and "false" could be used]], 
[[mhd_cv_macro_true_false_valid]],
-  [AC_COMPILE_IFELSE(
-     [AC_LANG_PROGRAM(
-        [[
-#ifdef HAVE_STDBOOL_H
-#include <stdbool.h>
-#endif
-        ]], [[
-          int var1[true ? 1 : -1] = { 1 };
-          int var2[false ? -1 : 1] = { 2 };
-          int var3[!true ? -1 : 1] = { 3 };
-          int var4[!false ? 1 : -1] = { 4 };
-          if (var1[0] == var2[0] || var3[0] == var4[0])
-            return 1;
-        ]])
-     ], [[mhd_cv_macro_true_false_valid='yes']], 
[[mhd_cv_macro_true_false_valid='no']])
-  ])
-AS_VAR_IF([[mhd_cv_macro_true_false_valid]], [["yes"]], [[:]],
-  [AC_MSG_ERROR([[Value of "true" or value of "false" is not valid. Check 
config.log for details.]])])
-
+MHD_BOOL
 
 AX_CHECK_COMPILE_FLAG([[-Werror=attributes]],
   [
diff --git a/m4/mhd_bool.m4 b/m4/mhd_bool.m4
new file mode 100644
index 00000000..b25d9abf
--- /dev/null
+++ b/m4/mhd_bool.m4
@@ -0,0 +1,135 @@
+# SYNOPSIS
+#
+#   MHD_BOOL
+#
+# DESCRIPTION
+#
+#   This macro checks whether the boolean keywords "bool", "true", "false"
+#   are supported by compiler. If they are not supported, a suitable
+#   replacement macros are defined
+#
+#   Example usage:
+#
+#     MHD_BOOL
+#
+#   The cache variables are used in check so if any test will not work
+#   correctly on some platform, user may simply fix it by giving cache
+#   variable in configure parameters, for example:
+#
+#     ./configure mhd_cv_bool_native=no
+#
+#   This simplify building from source on exotic platforms as patching
+#   of configure.ac is not required to change results of tests.
+#
+# LICENSE
+#
+#   Copyright (c) 2024 Karlson2k (Evgeny Grin) <k2k@narod.ru>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 1
+
+AC_DEFUN([MHD_BOOL],[dnl
+AC_PREREQ([2.64])dnl for AS_VAR_IF
+m4_newline([[# Expansion of macro $0 starts here]])
+AC_LANG_ASSERT([C])dnl
+AC_REQUIRE([AC_PROG_CC])dnl
+AH_TEMPLATE([[HAVE_STDBOOL_H]], [Define to 1 i][f you have the <stdbool.h> 
header file and <stdbool.h> is required to use 'bool' type.])dnl
+AH_TEMPLATE([[HAVE_BUILTIN_TYPE_BOOL]], [Define to 1 i][f you have the boolean 
type that takes only 'true' and 'false'.])dnl
+AH_TEMPLATE([[bool]], [Define to the name of the type which is used as a 
replacemnt f][or boolean type.])dnl
+[mhd_bool_test_code='
+static bool get_false(void)
+{
+  static bool test_arr[sizeof(bool)*2 - 1] = {false};
+  return test_arr[0];
+}
+
+int main(void)
+{
+  static bool var1 = true;
+  static bool var2 = false;
+  static int int_arr[2 - 3 * ((int) (false))] = {(int) true, (int) false};
+  static bool bool_arr[2 - 3 * ((int) (!true))] = {false, true};
+  i][f(!var1 || var2 || !int_arr[0] || int_arr[1] || bool_arr[0] ||
+     !bool_arr[1] || get_false() || 0 == sizeof(bool) || false || !true)
+    return 5;
+  return 0;
+}
+']
+AC_CACHE_CHECK([[whether "bool", "true" and "false" work 
natively]],[[mhd_cv_bool_native]],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[${mhd_bool_test_code}]])],[mhd_cv_bool_native="yes"],
+[mhd_cv_bool_native="no"])dnl AC_COMPILE_IFELSE
+])
+AS_VAR_IF([mhd_cv_bool_native],["yes"],[
+AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]],[1])],[dnl mhd_cv_bool_native "yes"
+AC_CACHE_CHECK([[whether <stdbool.h> is present and defines proper "bool", 
"true" and "false"]],[[mhd_cv_bool_stdbool]],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#include <stdbool.h>
+
+${mhd_bool_test_code}
+]])],[mhd_cv_bool_stdbool="yes"],[mhd_cv_bool_stdbool="no"])dnl 
AC_COMPILE_IFELSE
+])
+dnl end of AC_CACHE_CHECK
+AS_VAR_IF([mhd_cv_bool_stdbool],["yes"],[
+AC_DEFINE([[HAVE_STDBOOL_H]],[1])
+AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]],[1])],[dnl mhd_cv_bool_stdbool "yes"
+# Need 'bool', 'false' and 'true'.
+AC_CHECK_TYPE([bool],[AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]], [[1]])],[dnl 
AC_CHECK_TYPE bool
+AC_CHECK_TYPE([_Bool],[AC_DEFINE([[HAVE_BUILTIN_TYPE_BOOL]], [[1]])
+AC_DEFINE([[bool]], [[_Bool]])],[AC_DEFINE([[bool]], [[int]])
+],[[]])dnl AC_CHECK_TYPE _Bool
+],[[]])dnl AC_CHECK_TYPE bool
+# Have 'bool'. Need 'false' and 'true'.
+AC_CACHE_CHECK([[whether "false" keyword available and 
works]],[[mhd_cv_keyword_false_works]],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+int main(void)
+{
+  static bool var1 = false || false;
+  static bool var2 = false;
+  static bool bool_arr[2 - 3 * ((int) (false))] = {false, (bool) 0};
+  i][f(var1 || var2 || bool_arr[0] || bool_arr[1] || false)
+    return 5;
+  return 0;
+}
+]])], [[mhd_cv_keyword_false_works='yes']], 
[[mhd_cv_keyword_false_works='no']])])
+dnl end of AC_CACHE_CHECK
+AS_VAR_IF([[mhd_cv_keyword_false_works]], [["no"]],[dnl
+AC_DEFINE([[false]],[[(0)]], [Define to value interpreted by compiler as 
boolean "false", i][f "false" is not a keyword and not defined by headers.])])
+dnl AS_VAR_IF mhd_cv_keyword_false_works
+# Have 'bool' and 'false'. Need 'true'.
+AC_CACHE_CHECK([[whether "true" keyword available and 
works]],[[mhd_cv_keyword_true_works]],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+int main(void)
+{
+  static bool var1 = true && true;
+  static bool var2 = true;
+  static bool bool_arr[2 - 3 * ((int) (!true))] = {true, !false};
+  i][f(!var1 || !var2 || !bool_arr[0] || !bool_arr[1] || false)
+    return 5;
+  return 0;
+}
+]])], [[mhd_cv_keyword_true_works='yes']], 
[[mhd_cv_keyword_true_works='no']])])
+dnl end of AC_CACHE_CHECK
+AS_VAR_IF([[mhd_cv_keyword_true_works]], [["no"]],[dnl
+AC_DEFINE([[true]],[[(!false)]], [Define to value interpreted by compiler as 
boolean "true", i][f "true" is not a keyword and not defined by headers.])])
+dnl AS_VAR_IF mhd_cv_keyword_false_works
+# Have 'bool', 'false' and 'true'.
+AC_CACHE_CHECK([[whether the defined "bool", "true" and "false" can work 
together]],[[mhd_cv_bool_true_false_work]],
+[AC_COMPILE_IFELSE([AC_LANG_SOURCE([[${mhd_bool_test_code}]])],[mhd_cv_bool_true_false_work="yes"],
+[mhd_cv_bool_true_false_work="no"])dnl AC_COMPILE_IFELSE
+])
+dnl end of AC_CACHE_CHECK
+AS_VAR_IF([[mhd_cv_bool_true_false_work]], [["yes"]],[[:]],[dnl
+AC_MSG_FAILURE([cannot find suitable replacemnt for "bool", "true" and 
"false"])
+])
+dnl end of AS_VAR_IF mhd_cv_bool_true_false_work "yes"
+])
+dnl end of AS_VAR_IF mhd_cv_bool_stdbool "yes"
+])
+dnl end of AS_VAR_IF mhd_cv_bool_native "yes"
+AS_UNSET([mhd_bool_test_code])
+m4_newline([[# Expansion of macro $0 ends here]])
+])dnl AC_DEFUN MHD_BOOL

-- 
To stop receiving notification emails like this one, please contact
gnunet@gnunet.org.