Variadic C functions now count arguments with ptrdiff_t.

This partly undoes my 2011-03-30 change, which replaced int with size_t.
Back then I didn't know that the Emacs coding style prefers signed int.
Also, in the meantime I found a few more instances where arguments
were being counted with int, which may truncate counts on 64-bit
machines, or EMACS_INT, which may be unnecessarily wide.
* lisp.h (struct Lisp_Subr.function.aMANY)
(DEFUN_ARGS_MANY, internal_condition_case_n, safe_call):
Arg counts are now ptrdiff_t, not size_t.
All variadic functions and their callers changed accordingly.
(struct gcpro.nvars): Now size_t, not size_t.  All uses changed.
* bytecode.c (exec_byte_code): Check maxdepth for overflow,
to avoid potential buffer overrun.  Don't assume arg counts fit in 'int'.
* callint.c (Fcall_interactively): Check arg count for overflow,
to avoid potential buffer overrun.  Use signed char, not 'int',
for 'varies' array, so that we needn't bother to check its size
calculation for overflow.
* editfns.c (Fformat): Use ptrdiff_t, not EMACS_INT, to count args.
* eval.c (apply_lambda):
* fns.c (Fmapconcat): Use XFASTINT, not XINT, to get args length.
(struct textprop_rec.argnum): Now ptrdiff_t, not int.  All uses changed.
(mapconcat): Use ptrdiff_t, not int and EMACS_INT, to count args.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/process.c b/src/process.c
index 9ff7dd198dd..5a26bf43146 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1272,11 +1272,11 @@ the command through a shell and redirect one of them using the shell
 syntax.
 
 usage: (start-process NAME BUFFER PROGRAM &rest PROGRAM-ARGS)  */)
-  (size_t nargs, register Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   Lisp_Object buffer, name, program, proc, current_dir, tem;
   register unsigned char **new_argv;
-  register size_t i;
+  ptrdiff_t i;
   int count = SPECPDL_INDEX ();
 
   buffer = args[1];
@@ -2436,7 +2436,7 @@ Examples:
 \(serial-process-configure :port "\\\\.\\COM13" :bytesize 7)
 
 usage: (serial-process-configure &rest ARGS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   struct Lisp_Process *p;
   Lisp_Object contact = Qnil;
@@ -2554,7 +2554,7 @@ Examples:
 \(make-serial-process :port "/dev/tty.BlueConsole-SPP-1" :speed nil)
 
 usage:  (make-serial-process &rest ARGS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   int fd = -1;
   Lisp_Object proc, contact, port;
@@ -2832,7 +2832,7 @@ The original argument list, modified with the actual connection
 information, is available via the `process-contact' function.
 
 usage: (make-network-process &rest ARGS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   Lisp_Object proc;
   Lisp_Object contact;
@@ -3148,7 +3148,7 @@ usage: (make-network-process &rest ARGS)  */)
 
   for (lres = res; lres; lres = lres->ai_next)
     {
-      size_t optn;
+      ptrdiff_t optn;
       int optbits;
 
 #ifdef WINDOWSNT