* lib/autoconf/c.m4 (_AC_PROG_CC_C89): Check for C89 incompatibility

when using default mode of IBM C 6 for AIX.  Problem and two-line
fix reported by Larry Jones.

diff --git a/ChangeLog b/ChangeLog
index d94fd92ac469dba86d27dc4af71846ca19e5eec2..444d8fa308e6ecad362091ca35e268001e7def69 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2006-06-22  Paul Eggert  <eggert@cs.ucla.edu>
+
+       * lib/autoconf/c.m4 (_AC_PROG_CC_C89): Check for C89 incompatibility
+       when using default mode of IBM C 6 for AIX.  Problem and two-line
+       fix reported by Larry Jones.
+
 2006-06-22  Alexandre Julliard <julliard@winehq.org>
 
        * lib/autoconf/status.m4 (_AC_OUTPUT_FILE): Avoid warning

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index b9e6e78ed6a14830620affa4585aff2fff838e97..dead340b40a85bb8f9ccc448d4919d6e7601117f 100644 (file)
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -1043,6 +1043,11 @@ static char *f (char * (*g) (char **, int), char **p, ...)
    that's true only with -std.  */
 int osf4_cc_array ['\x00' == 0 ? 1 : -1];
 
+/* IBM C 6 for AIX is almost-ANSI by default, but it replaces macro parameters
+   inside strings and character constants.  */
+#define FOO(x) 'x'
+int xlc6_cc_array[FOO(a) == 'x' ? 1 : -1];
+
 int test (int i, double x);
 struct s1 {int (*f) (int a);};
 struct s2 {int (*f) (double a);};