autoconf: new macro AC_HEADER_CHECK_STDBOOL

* NEWS: Document this.
* doc/autoconf.texi (Particular Headers): Likewise.
In example, don't assume a 'system.h' exists.
* lib/autoconf/headers.m4 (AC_CHECK_HEADER_STDBOOL): New macro.
Use it with AN_IDENTIFIER, since it's less heavyweight.
Reindent to match gnulib, since that's a bit nicer.
(AC_HEADER_STDBOOL): Reimplement in terms of it.

1 files changed, 72 insertions, 63 deletions

diff --git a/lib/autoconf/headers.m4 b/lib/autoconf/headers.m4
index 75bdfeff..4b028321 100644
--- a/lib/autoconf/headers.m4
+++ b/lib/autoconf/headers.m4
@@ -591,72 +591,81 @@ fi
 ])# AC_HEADER_STAT
 
 
-# AC_HEADER_STDBOOL
+# AC_CHECK_HEADER_STDBOOL
 # -----------------
 # Check for stdbool.h that conforms to C99.
-AN_IDENTIFIER([bool], [AC_HEADER_STDBOOL])
-AN_IDENTIFIER([true], [AC_HEADER_STDBOOL])
-AN_IDENTIFIER([false],[AC_HEADER_STDBOOL])
-AC_DEFUN([AC_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>
-#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
+AN_IDENTIFIER([bool], [AC_CHECK_HEADER_STDBOOL])
+AN_IDENTIFIER([true], [AC_CHECK_HEADER_STDBOOL])
+AN_IDENTIFIER([false],[AC_CHECK_HEADER_STDBOOL])
+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>
+             #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];
+             /* 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
+                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;
+           ]],
+           [[
+             bool e = &s;
+             *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])
+])# AC_CHECK_HEADER_STDBOOL
+
 
-	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];
-	/* 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
-	   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;
-      ]],
-      [[
-	bool e = &s;
-	*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])
+# AC_HEADER_STDBOOL
+# -----------------
+# Define HAVE_STDBOOL_H if tdbool.h that conforms to C99.
+AC_DEFUN([AC_HEADER_STDBOOL],
+[AC_CHECK_HEADER_STDBOOL
 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