Warn when fseek or ftell are used.

diff --git a/ChangeLog b/ChangeLog
index 5963fff398d3008f1199e6bc29931618a6f22860..3987866167c5959549f2a1f808ccccb13eded46b 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2007-04-28  Bruno Haible  <bruno@clisp.org>
+
+       * lib/stdio_.h (fseek, ftell): Provide link warnings suggesting to use
+       fseeko and ftello.
+       Suggested by Eric Blake.
+
 2007-04-28  Jim Meyering  <jim@meyering.net>
 
        Avoid false-negative in gl_STDINT_H's C99 conformance test.

diff --git a/lib/stdio_.h b/lib/stdio_.h
index 0e35ffd0371edb36f6d4e3fdb522c14e108808d9..66311be852ad6c2cde8321b87d873958158e465b 100644 (file)
--- a/lib/stdio_.h
+++ b/lib/stdio_.h
@@ -231,6 +231,16 @@ typedef int verify_fseeko_types[2 * (sizeof (off_t) == sizeof (long)) - 1];
     fseeko (f, o, w))
 #endif
 
+#if defined GNULIB_POSIXCHECK
+# ifndef fseek
+#  define fseek(f,o,w) \
+     (GL_LINK_WARNING ("fseek cannot handle files larger than 4 GB " \
+                       "on 32-bit platforms - " \
+                       "use fseeko function for handling of large files"), \
+      fseek (f, o, w))
+# endif
+#endif
+
 #if @GNULIB_FTELLO@
 # if !@HAVE_FTELLO@
 /* Assume 'off_t' is the same type as 'long'.  */
@@ -245,6 +255,16 @@ typedef int verify_ftello_types[2 * (sizeof (off_t) == sizeof (long)) - 1];
     ftello (f))
 #endif
 
+#if defined GNULIB_POSIXCHECK
+# ifndef ftell
+#  define ftell(f) \
+     (GL_LINK_WARNING ("ftell cannot handle files larger than 4 GB " \
+                       "on 32-bit platforms - " \
+                       "use ftello function for handling of large files"), \
+      ftell (f))
+# endif
+#endif
+
 #if @GNULIB_FFLUSH@
 # if @REPLACE_FFLUSH@
 #  define fflush rpl_fflush