retire GNULIB_PORTCHECK

[Bruno Haible]

The macro GNULIB_PORTCHECK, used in time.in.h, effectively means the same
as GNULIB_POSIXCHECK. It dates back to a time when Eric had not implemented
GNULIB_POSIXCHECK and not invented warn-on-use.

This patch modernizes this code and uses the common idiom.


2010-03-27  Bruno Haible  <address@hidden>

        Use GNULIB_POSIXCHECK instead of GNULIB_PORTCHECK.
        * lib/time.in.h (asctime, asctime_r, ctime, ctime_r): Test
        GNULIB_POSIXCHECK, not GNULIB_PORTCHECK. Provide compile-time warnings
        rather than link errors.

--- lib/time.in.h.orig  Sat Mar 27 20:06:04 2010
+++ lib/time.in.h       Sat Mar 27 20:04:24 2010
@@ -185,15 +185,25 @@
 /* Encourage applications to avoid unsafe functions that can overrun
    buffers when given outlandish struct tm values.  Portable
    applications should use strftime (or even sprintf) instead.  */
-# if GNULIB_PORTCHECK
+# if defined GNULIB_POSIXCHECK
 #  undef asctime
-#  define asctime eschew_asctime
+_GL_WARN_ON_USE (asctime, "asctime can overrun buffers in some cases - "
+                 "better use strftime (or even sprintf) instead");
+# endif
+# if defined GNULIB_POSIXCHECK
 #  undef asctime_r
-#  define asctime_r eschew_asctime_r
+_GL_WARN_ON_USE (asctime, "asctime_r can overrun buffers in some cases - "
+                 "better use strftime (or even sprintf) instead");
+# endif
+# if defined GNULIB_POSIXCHECK
 #  undef ctime
-#  define ctime eschew_ctime
+_GL_WARN_ON_USE (asctime, "ctime can overrun buffers in some cases - "
+                 "better use strftime (or even sprintf) instead");
+# endif
+# if defined GNULIB_POSIXCHECK
 #  undef ctime_r
-#  define ctime_r eschew_ctime_r
+_GL_WARN_ON_USE (asctime, "ctime_r can overrun buffers in some cases - "
+                 "better use strftime (or even sprintf) instead");
 # endif
 
 #endif