Re: Can anyone help with #112770?

[Lukas Geyer <geyer@ml.kva.se>]

On Sat, 19 Jan 2002, Chris Tillman wrote:

> The upshot is that powerpc compilers enforce the correct usage of
> varargs, where most i386 compilers do not. It's not really a powerpc
> specific problem.

Yep, and here is a patch, against the current sid source, untested, maybe
someone should test this or rather redesign the interface relating to
xvsprintf() and stuff. The manpage to vsnprintf() explicitly says that the
va_list contains something undefined afterwards, so one cannot call it
twice in a row without va_end(), va_start() in between.

Lukas

The patch:

diff -purN ratpoison-1.0.0.cvs.20020117/src/bar.c ratpoison-1.0.0.cvs.20020117.mod/src/bar.c
--- ratpoison-1.0.0.cvs.20020117/src/bar.c	Fri Dec 21 12:58:56 2001
+++ ratpoison-1.0.0.cvs.20020117.mod/src/bar.c	Sun Jan 20 17:21:28 2002
@@ -124,7 +124,7 @@ marked_message_printf (int mark_start, i
   va_list ap;

   va_start (ap, fmt);
-  buffer = xvsprintf (fmt, ap);
+  xvsprintf (buffer, fmt, ap);
   va_end (ap);

   marked_message (buffer, mark_start, mark_end);
diff -purN ratpoison-1.0.0.cvs.20020117/src/main.c ratpoison-1.0.0.cvs.20020117.mod/src/main.c
--- ratpoison-1.0.0.cvs.20020117/src/main.c	Wed Jan 16 21:55:17 2002
+++ ratpoison-1.0.0.cvs.20020117.mod/src/main.c	Sun Jan 20 17:02:22 2002
@@ -126,47 +126,13 @@ xstrdup (char *s)

 /* Return a new string based on fmt. */
 char *
-xvsprintf (char *fmt, va_list ap)
-{
-  int size, nchars;
-  char *buffer;
-
-  /* A resonable starting value. */
-  size = strlen (fmt) + 1;
-  buffer = (char *)xmalloc (size);
-
-  nchars = vsnprintf (buffer, size, fmt, ap);
-
-  /* From the GNU Libc manual: In versions of the GNU C library prior
-     to 2.1 the return value is the number of characters stored, not
-     including the terminating null; unless there was not enough space
-     in S to store the result in which case `-1' is returned. */
-  if (nchars == -1)
-    {
-      do
-	{
-	  size *= 2;
-	  buffer = (char *)xrealloc (buffer, size);
-	} while (vsnprintf (buffer, size, fmt, ap) == -1);
-    }
-  else if (nchars >= size)
-    {
-      buffer = (char *)xrealloc (buffer, nchars + 1);
-      vsnprintf (buffer, nchars + 1, fmt, ap);
-    }
-
-  return buffer;
-}
-
-/* Return a new string based on fmt. */
-char *
 xsprintf (char *fmt, ...)
 {
   char *buffer;
   va_list ap;

   va_start (ap, fmt);
-  buffer = xvsprintf (fmt, ap);
+  xvsprintf (buffer, fmt, ap);
   va_end (ap);

   return buffer;
diff -purN ratpoison-1.0.0.cvs.20020117/src/ratpoison.h ratpoison-1.0.0.cvs.20020117.mod/src/ratpoison.h
--- ratpoison-1.0.0.cvs.20020117/src/ratpoison.h	Fri Dec 21 12:58:56 2001
+++ ratpoison-1.0.0.cvs.20020117.mod/src/ratpoison.h	Sun Jan 20 17:05:22 2002
@@ -70,6 +70,43 @@ void *xmalloc (size_t size);
 void *xrealloc (void *ptr, size_t size);
 char *xstrdup (char *s);
 char *xsprintf (char *fmt, ...);
-char *xvsprintf (char *fmt, va_list ap);
+
+/* Return a new string based on fmt. */
+
+/*
+ * This should be replaced by something cleaner. Maybe the authors
+ * should (re)read the manpages of vsnprintf and stdarg and redesign
+ * this interface.
+ */
+#define xvsprintf(buf,fmt,ap) \
+{ \
+  int size = strlen(fmt) + 1; \
+  int nchars; \
+  \
+  buf = xmalloc(size); \
+  nchars = vsnprintf (buf, size, fmt, ap); \
+  \
+  /* From the GNU Libc manual: In versions of the GNU C library prior  \
+     to 2.1 the return value is the number of characters stored, not   \
+     including the terminating null; unless there was not enough space \
+     in S to store the result in which case `-1' is returned. */       \
+  if (nchars == -1) \
+    { \
+      do \
+	{ \
+	  size *= 2; \
+	  buf = xrealloc (buf, size); \
+	  va_end(ap); \
+	  va_start(ap, fmt); \
+	} while (vsnprintf (buf, size, fmt, ap) == -1); \
+    } \
+  else if (nchars >= size) \
+    { \
+      buf = xrealloc (buf, nchars + 1); \
+      va_end(ap); \
+      va_start(ap, fmt); \
+      vsnprintf (buf, nchars + 1, fmt, ap); \
+    } \
+}

 #endif /* ! _RATPOISON_H */
diff -purN ratpoison-1.0.0.cvs.20020117/src/sbuf.c ratpoison-1.0.0.cvs.20020117.mod/src/sbuf.c
--- ratpoison-1.0.0.cvs.20020117/src/sbuf.c	Fri Dec 21 12:58:56 2001
+++ ratpoison-1.0.0.cvs.20020117.mod/src/sbuf.c	Sun Jan 20 17:00:58 2002
@@ -98,7 +98,7 @@ sbuf_printf (struct sbuf *b, char *fmt,
   free (b->data);

   va_start (ap, fmt);
-  b->data = xvsprintf (fmt, ap);
+  xvsprintf (b->data, fmt, ap);
   va_end (ap);

   return b->data;
@@ -111,7 +111,7 @@ sbuf_printf_concat (struct sbuf *b, char
   va_list ap;

   va_start (ap, fmt);
-  buffer = xvsprintf (fmt, ap);
+  xvsprintf (buffer, fmt, ap);
   va_end (ap);

   sbuf_concat (b, buffer);