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, 8 insertions, 8 deletions

diff --git a/src/lisp.h b/src/lisp.h
index 3f6a84f8fa3..83534e55433 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -1039,7 +1039,7 @@ struct Lisp_Subr
       Lisp_Object (*a7) (Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object);
       Lisp_Object (*a8) (Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object);
       Lisp_Object (*aUNEVALLED) (Lisp_Object args);
-      Lisp_Object (*aMANY) (size_t, Lisp_Object *);
+      Lisp_Object (*aMANY) (ptrdiff_t, Lisp_Object *);
     } function;
     short min_args, max_args;
     const char *symbol_name;
@@ -1896,7 +1896,7 @@ typedef struct {
 
 /* Note that the weird token-substitution semantics of ANSI C makes
    this work for MANY and UNEVALLED.  */
-#define DEFUN_ARGS_MANY         (size_t, Lisp_Object *)
+#define DEFUN_ARGS_MANY         (ptrdiff_t, Lisp_Object *)
 #define DEFUN_ARGS_UNEVALLED    (Lisp_Object)
 #define DEFUN_ARGS_0    (void)
 #define DEFUN_ARGS_1    (Lisp_Object)
@@ -2161,7 +2161,7 @@ struct gcpro
   volatile Lisp_Object *var;
 
   /* Number of consecutive protected variables.  */
-  size_t nvars;
+  ptrdiff_t nvars;
 
 #ifdef DEBUG_GCPRO
   int level;
@@ -2922,9 +2922,9 @@ EXFUN (Frun_hooks, MANY);
 EXFUN (Frun_hook_with_args, MANY);
 EXFUN (Frun_hook_with_args_until_failure, MANY);
 extern void run_hook_with_args_2 (Lisp_Object, Lisp_Object, Lisp_Object);
-extern Lisp_Object run_hook_with_args (size_t nargs, Lisp_Object *args,
+extern Lisp_Object run_hook_with_args (ptrdiff_t nargs, Lisp_Object *args,
                                        Lisp_Object (*funcall)
-                                       (size_t nargs, Lisp_Object *args));
+                                       (ptrdiff_t nargs, Lisp_Object *args));
 EXFUN (Fprogn, UNEVALLED);
 EXFUN (Finteractive_p, 0);
 EXFUN (Fthrow, 2) NO_RETURN;
@@ -2956,7 +2956,7 @@ extern Lisp_Object internal_lisp_condition_case (Lisp_Object, Lisp_Object, Lisp_
 extern Lisp_Object internal_condition_case (Lisp_Object (*) (void), Lisp_Object, Lisp_Object (*) (Lisp_Object));
 extern Lisp_Object internal_condition_case_1 (Lisp_Object (*) (Lisp_Object), Lisp_Object, Lisp_Object, Lisp_Object (*) (Lisp_Object));
 extern Lisp_Object internal_condition_case_2 (Lisp_Object (*) (Lisp_Object, Lisp_Object), Lisp_Object, Lisp_Object, Lisp_Object, Lisp_Object (*) (Lisp_Object));
-extern Lisp_Object internal_condition_case_n (Lisp_Object (*) (size_t, Lisp_Object *), size_t, Lisp_Object *, Lisp_Object, Lisp_Object (*) (Lisp_Object));
+extern Lisp_Object internal_condition_case_n (Lisp_Object (*) (ptrdiff_t, Lisp_Object *), ptrdiff_t, Lisp_Object *, Lisp_Object, Lisp_Object (*) (Lisp_Object));
 extern void specbind (Lisp_Object, Lisp_Object);
 extern void record_unwind_protect (Lisp_Object (*) (Lisp_Object), Lisp_Object);
 extern Lisp_Object unbind_to (int, Lisp_Object);
@@ -2966,7 +2966,7 @@ extern void verror (const char *, va_list)
 extern void do_autoload (Lisp_Object, Lisp_Object);
 extern Lisp_Object un_autoload (Lisp_Object);
 extern void init_eval_once (void);
-extern Lisp_Object safe_call (size_t, Lisp_Object *);
+extern Lisp_Object safe_call (ptrdiff_t, Lisp_Object *);
 extern Lisp_Object safe_call1 (Lisp_Object, Lisp_Object);
 extern Lisp_Object safe_call2 (Lisp_Object, Lisp_Object, Lisp_Object);
 extern void init_eval (void);
@@ -3348,7 +3348,7 @@ extern void mark_byte_stack (void);
 #endif
 extern void unmark_byte_stack (void);
 extern Lisp_Object exec_byte_code (Lisp_Object, Lisp_Object, Lisp_Object,
-                                   Lisp_Object, int, Lisp_Object *);
+                                   Lisp_Object, ptrdiff_t, Lisp_Object *);
 
 /* Defined in macros.c */
 extern Lisp_Object Qexecute_kbd_macro;