error: Print 32- and 64-bit integers portably (Bug#8435).

Without this change, on typical 64-bit hosts error ("...%d...", N)
was used to print both 32- and 64-bit integers N, which relied on
undefined behavior.
* lisp.h, src/m/amdx86-64.h, src/m/ia64.h, src/m/ibms390x.h (pEd):
New macro.
* lisp.h (error, verror): Mark as printf-like functions.
* eval.c (verror): Use vsnprintf, not doprnt, to do the real work.
Report overflow in size calculations when allocating printf buffer.
Do not truncate output string at its first null byte.
* xdisp.c (vmessage): Use vsnprintf, not doprnt, to do the real work.
Truncate the output at a character boundary, since vsnprintf does not
do that.
* charset.c (check_iso_charset_parameter): Convert internal
character to string before calling 'error', since %c now has the
printf meaning.
* coding.c (Fdecode_sjis_char, Fdecode_big5_char): Avoid int
overflow when computing char to be passed to 'error'.  Do not
pass Lisp_Object to 'error'; pass the integer instead.
* nsfns.m (Fns_do_applescript): Use int, not long, since it's
formatted with plain %d.

1 files changed, 13 insertions, 8 deletions

diff --git a/src/eval.c b/src/eval.c
index 8b029967e7a..77411a911ee 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1977,21 +1977,26 @@ void
 verror (const char *m, va_list ap)
 {
   char buf[200];
-  EMACS_INT size = 200;
-  int mlen;
+  size_t size = sizeof buf;
+  size_t size_max = (size_t) -1;
   char *buffer = buf;
   int allocated = 0;
+  int used;
   Lisp_Object string;
 
-  mlen = strlen (m);
-
   while (1)
     {
-      EMACS_INT used;
-      used = doprnt (buffer, size, m, m + mlen, ap);
+      used = vsnprintf (buffer, size, m, ap);
+      if (used < 0)
+        used = 0;
       if (used < size)
         break;
-      size *= 2;
+      if (size <= size_max / 2)
+        size *= 2;
+      else if (size < size_max)
+        size = size_max;
+      else
+        memory_full ();
       if (allocated)
         buffer = (char *) xrealloc (buffer, size);
       else
@@ -2001,7 +2006,7 @@ verror (const char *m, va_list ap)
         }
     }
 
-  string = build_string (buffer);
+  string = make_string (buffer, used);
   if (allocated)
     xfree (buffer);