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/callproc.c b/src/callproc.c
index 7bb2ac05933..d6bad2a44e7 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -184,7 +184,7 @@ and returns a numeric exit status or a signal description string.
 If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.
 
 usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
-  (size_t nargs, register Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   Lisp_Object infile, buffer, current_dir, path;
   volatile int display_p_volatile;
@@ -231,7 +231,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
   /* Decide the coding-system for giving arguments.  */
   {
     Lisp_Object val, *args2;
-    size_t i;
+    ptrdiff_t i;
 
     /* If arguments are supplied, we may have to encode them.  */
     if (nargs >= 5)
@@ -422,7 +422,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
                (nargs > 4 ? nargs - 2 : 2) * sizeof *new_argv);
   if (nargs > 4)
     {
-      register size_t i;
+      ptrdiff_t i;
       struct gcpro gcpro1, gcpro2, gcpro3, gcpro4, gcpro5;
 
       GCPRO5 (infile, buffer, current_dir, path, error_file);
@@ -716,7 +716,7 @@ usage: (call-process PROGRAM &optional INFILE BUFFER DISPLAY &rest ARGS)  */)
         {
           if (EQ (coding_systems, Qt))
             {
-              size_t i;
+              ptrdiff_t i;
 
               SAFE_ALLOCA (args2, Lisp_Object *, (nargs + 1) * sizeof *args2);
               args2[0] = Qcall_process;
@@ -944,7 +944,7 @@ and returns a numeric exit status or a signal description string.
 If you quit, the process is killed with SIGINT, or SIGKILL if you quit again.
 
 usage: (call-process-region START END PROGRAM &optional DELETE BUFFER DISPLAY &rest ARGS)  */)
-  (size_t nargs, register Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   struct gcpro gcpro1;
   Lisp_Object filename_string;
@@ -953,7 +953,7 @@ usage: (call-process-region START END PROGRAM &optional DELETE BUFFER DISPLAY &r
   /* Qt denotes we have not yet called Ffind_operation_coding_system.  */
   Lisp_Object coding_systems;
   Lisp_Object val, *args2;
-  size_t i;
+  ptrdiff_t i;
   char *tempfile;
   Lisp_Object tmpdir, pattern;