[RFA] Eliminate warnings about snprintf declaration

[Eli Zaretskii]

> Date: Mon, 15 Nov 2004 19:36:45 -0500
> From: Andrew Cagney <cagney@gnu.org>
> Cc: gdb@sources.redhat.com
> 
> Eli Zaretskii wrote:
> > When I build GDB with DJGPP, GCC whines like so:
> > 
> >     remote.c: In function `remote_xfer_partial':
> >     remote.c:4920: warning: implicit declaration of function `snprintf'
> > 
> > (I see this warning for other source files as well.)
> > 
> > This happens because DJGPP doesn't have `snprintf' in its library, so
> > the libiberty version is used.  But there's no prototype for the
> > libiberty `snprintf' anywhere, thus the warning.  The code seems to be
> > relying on getting the prototype from stdio.h, but if the library
> > doesn't have the function, we cannot expect to have the prototype on a
> > standard header.
> > 
> > What would be the canonical way to fix that?
> 
> include/libiberty.h, for instance:
> 
> > #if !HAVE_DECL_ASPRINTF
> > /* Like sprintf but provides a pointer to malloc'd storage, which must
> >    be freed by the caller.  */
> > 
> > extern int asprintf PARAMS ((char **, const char *, ...)) ATTRIBUTE_PRINTF_2;
> > #endif

Okay, here're the patches to add snprintf and vsnprintf to the list of
functions whose declarations are checked at configure time.  Comments?


libiberty/ChangeLog:
2005-05-12  Eli Zaretskii  <eliz@gnu.org>

	* configure.ac: Add snprintf and vsnprintf to AC_CHEK_DECLS.


include/ChangeLog:
2005-05-12  Eli Zaretskii  <eliz@gnu.org>

	* libiberty.h (snprintf) [!HAVE_DECL_SNPRINTF]: Add a prototype.
	(vsnprintf) [!HAVE_DECL_VSNPRINTF]: Add a prototype.


Index: libiberty/configure.ac
===================================================================
RCS file: /cvs/src/src/libiberty/configure.ac,v
retrieving revision 1.22
diff -u -r1.22 configure.ac
--- libiberty/configure.ac	7 May 2005 02:00:41 -0000	1.22
+++ libiberty/configure.ac	12 May 2005 14:55:28 -0000
@@ -282,7 +282,7 @@
   sysconf times sbrk gettimeofday ffs snprintf vsnprintf \
   pstat_getstatic pstat_getdynamic sysmp getsysinfo table sysctl wait3 wait4 \
   realpath canonicalize_file_name __fsetlocking)
-  AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf])
+  AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf])
   AC_DEFINE(HAVE_SYS_ERRLIST, 1, [Define if you have the sys_errlist variable.])
   AC_DEFINE(HAVE_SYS_NERR,    1, [Define if you have the sys_nerr variable.])
   AC_DEFINE(HAVE_SYS_SIGLIST, 1, [Define if you have the sys_siglist variable.])
@@ -518,7 +518,7 @@
     [AC_MSG_RESULT([no])])
 
   AC_CHECK_FUNCS($checkfuncs)
-  AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf])
+  AC_CHECK_DECLS([basename, ffs, asprintf, vasprintf, snprintf, vsnprintf])
   libiberty_NEED_DECLARATION(canonicalize_file_name)
 fi
 
Index: include/libiberty.h
===================================================================
RCS file: /cvs/src/src/include/libiberty.h,v
retrieving revision 1.43
diff -u -r1.43 libiberty.h
--- include/libiberty.h	10 May 2005 10:21:08 -0000	1.43
+++ include/libiberty.h	12 May 2005 14:56:04 -0000
@@ -528,6 +528,24 @@
   ATTRIBUTE_PRINTF(2,0);
 #endif
 
+#if !HAVE_DECL_SNPRINTF
+# ifdef HAVE_DECL_SNPRINTF
+  extern int snprintf ();
+# else
+/* Like sprintf but prints at most N characters.  */
+  extern int snprintf (char *, size_t, const char *, ...) ATTRIBUTE_PRINTF_3;
+# endif
+#endif
+
+#if !HAVE_DECL_VSNPRINTF
+# ifdef HAVE_DECL_VSNPRINTF
+  extern int vsnprintf ();
+# else
+/* Like vsprintf but prints at most N characters.  */
+  extern int vsnprintf (char *, size_t, const char *, va_list);
+# endif
+#endif
+
 #define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
 
 /* Drastically simplified alloca configurator.  If we're using GCC,