[RFA] Eliminate warnings about snprintf declaration

Eli Zaretskii
2005-05-12T14:59:33Z

> 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,