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, 17 insertions, 17 deletions

diff --git a/src/data.c b/src/data.c
index a239a89c2d4..cf01d38036d 100644
--- a/src/data.c
+++ b/src/data.c
@@ -2503,18 +2503,18 @@ enum arithop
     Amin
   };
 
-static Lisp_Object float_arith_driver (double, size_t, enum arithop,
-                                       size_t, Lisp_Object *);
+static Lisp_Object float_arith_driver (double, ptrdiff_t, enum arithop,
+                                       ptrdiff_t, Lisp_Object *);
 static Lisp_Object
-arith_driver (enum arithop code, size_t nargs, register Lisp_Object *args)
+arith_driver (enum arithop code, ptrdiff_t nargs, Lisp_Object *args)
 {
   register Lisp_Object val;
-  register size_t argnum;
+  ptrdiff_t argnum;
   register EMACS_INT accum = 0;
   register EMACS_INT next;
 
   int overflow = 0;
-  size_t ok_args;
+  ptrdiff_t ok_args;
   EMACS_INT ok_accum;
 
   switch (SWITCH_ENUM_CAST (code))
@@ -2618,8 +2618,8 @@ arith_driver (enum arithop code, size_t nargs, register Lisp_Object *args)
 #define isnan(x) ((x) != (x))
 
 static Lisp_Object
-float_arith_driver (double accum, register size_t argnum, enum arithop code,
-                    size_t nargs, register Lisp_Object *args)
+float_arith_driver (double accum, ptrdiff_t argnum, enum arithop code,
+                    ptrdiff_t nargs, Lisp_Object *args)
 {
   register Lisp_Object val;
   double next;
@@ -2681,7 +2681,7 @@ float_arith_driver (double accum, register size_t argnum, enum arithop code,
 DEFUN ("+", Fplus, Splus, 0, MANY, 0,
        doc: /* Return sum of any number of arguments, which are numbers or markers.
 usage: (+ &rest NUMBERS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Aadd, nargs, args);
 }
@@ -2691,7 +2691,7 @@ DEFUN ("-", Fminus, Sminus, 0, MANY, 0,
 With one arg, negates it.  With more than one arg,
 subtracts all but the first from the first.
 usage: (- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Asub, nargs, args);
 }
@@ -2699,7 +2699,7 @@ usage: (- &optional NUMBER-OR-MARKER &rest MORE-NUMBERS-OR-MARKERS)  */)
 DEFUN ("*", Ftimes, Stimes, 0, MANY, 0,
        doc: /* Return product of any number of arguments, which are numbers or markers.
 usage: (* &rest NUMBERS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Amult, nargs, args);
 }
@@ -2708,9 +2708,9 @@ DEFUN ("/", Fquo, Squo, 2, MANY, 0,
        doc: /* Return first argument divided by all the remaining arguments.
 The arguments must be numbers or markers.
 usage: (/ DIVIDEND DIVISOR &rest DIVISORS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
-  size_t argnum;
+  ptrdiff_t argnum;
   for (argnum = 2; argnum < nargs; argnum++)
     if (FLOATP (args[argnum]))
       return float_arith_driver (0, 0, Adiv, nargs, args);
@@ -2792,7 +2792,7 @@ DEFUN ("max", Fmax, Smax, 1, MANY, 0,
        doc: /* Return largest of all the arguments (which must be numbers or markers).
 The value is always a number; markers are converted to numbers.
 usage: (max NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Amax, nargs, args);
 }
@@ -2801,7 +2801,7 @@ DEFUN ("min", Fmin, Smin, 1, MANY, 0,
        doc: /* Return smallest of all the arguments (which must be numbers or markers).
 The value is always a number; markers are converted to numbers.
 usage: (min NUMBER-OR-MARKER &rest NUMBERS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Amin, nargs, args);
 }
@@ -2810,7 +2810,7 @@ DEFUN ("logand", Flogand, Slogand, 0, MANY, 0,
        doc: /* Return bitwise-and of all the arguments.
 Arguments may be integers, or markers converted to integers.
 usage: (logand &rest INTS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Alogand, nargs, args);
 }
@@ -2819,7 +2819,7 @@ DEFUN ("logior", Flogior, Slogior, 0, MANY, 0,
        doc: /* Return bitwise-or of all the arguments.
 Arguments may be integers, or markers converted to integers.
 usage: (logior &rest INTS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Alogior, nargs, args);
 }
@@ -2828,7 +2828,7 @@ DEFUN ("logxor", Flogxor, Slogxor, 0, MANY, 0,
        doc: /* Return bitwise-exclusive-or of all the arguments.
 Arguments may be integers, or markers converted to integers.
 usage: (logxor &rest INTS-OR-MARKERS)  */)
-  (size_t nargs, Lisp_Object *args)
+  (ptrdiff_t nargs, Lisp_Object *args)
 {
   return arith_driver (Alogxor, nargs, args);
 }