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, 23 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index e4e95ba5aa0..dc8f983c870 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,28 @@
 2011-06-14  Paul Eggert  <eggert@cs.ucla.edu>
 
+        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 be too narrow, or EMACS_INT, which
+        may be too 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.
+
         * callint.c (Fcall_interactively): Don't use index var as event count.
 
         * vm-limit.c (check_memory_limits): Fix incorrect extern function decls.