Use INT_ADD_WRAPV etc. to check integer overflow

* src/alloc.c (xnmalloc, xnrealloc, xpalloc, Fmake_string):
* src/buffer.c (record_overlay_string, overlay_strings):
* src/casefiddle.c (casify_object):
* src/ccl.c (Fccl_execute_on_string):
* src/character.c (char_width, c_string_width, lisp_string_width)
(count_size_as_multibyte, string_escape_byte8):
* src/coding.c (coding_alloc_by_realloc, produce_chars):
* src/data.c (arith_driver):
* src/dispnew.c (realloc_glyph_pool, init_display):
* src/editfns.c (styled_format):
* src/fns.c (Ffillarray):
* src/ftfont.c (ftfont_shape_by_flt):
* src/gnutls.c (gnutls_hex_string):
* src/gtkutil.c (get_utf8_string):
* src/image.c (x_to_xcolors, x_detect_edges, png_load_body):
* src/keymap.c (Fkey_description):
* src/lisp.h (SAFE_ALLOCA_LISP):
* src/term.c (encode_terminal_code):
* src/tparam.c (tparam1):
* src/xselect.c (x_property_data_to_lisp):
* src/xsmfns.c (smc_save_yourself_CB):
* src/xterm.c (x_term_init):
When checking for integer overflow, prefer INT_MULTIPLY_WRAPV to
more-complicated code involving division and/or
INT_MULTIPLY_OVERFLOW, and similarly for INT_ADD_WRAPV and
subtraction and/or INT_ADD_OVERFLOW.
* src/casefiddle.c (casify_object): Simplify multibyte size check.
* src/character.c: Remove some obsolete ‘#ifdef emacs’s.
* src/data.c (arith_driver): Also check for division overflow,
as that’s now possible given that the accumulator can now contain
any Emacs integer.
* src/lisp.h (lisp_word_count): Remove; no longer used.

1 files changed, 5 insertions, 6 deletions

diff --git a/src/buffer.c b/src/buffer.c
index c0179c7584e..ab91aaa4e81 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3245,9 +3245,9 @@ record_overlay_string (struct sortstrlist *ssl, Lisp_Object str,
   else
     nbytes = SBYTES (str);
 
-  if (INT_ADD_OVERFLOW (ssl->bytes, nbytes))
+  if (INT_ADD_WRAPV (ssl->bytes, nbytes, &nbytes))
     memory_full (SIZE_MAX);
-  ssl->bytes += nbytes;
+  ssl->bytes = nbytes;
 
   if (STRINGP (str2))
     {
@@ -3259,9 +3259,9 @@ record_overlay_string (struct sortstrlist *ssl, Lisp_Object str,
       else
         nbytes = SBYTES (str2);
 
-      if (INT_ADD_OVERFLOW (ssl->bytes, nbytes))
+      if (INT_ADD_WRAPV (ssl->bytes, nbytes, &nbytes))
         memory_full (SIZE_MAX);
-      ssl->bytes += nbytes;
+      ssl->bytes = nbytes;
     }
 }
 
@@ -3357,9 +3357,8 @@ overlay_strings (ptrdiff_t pos, struct window *w, unsigned char **pstr)
       unsigned char *p;
       ptrdiff_t total;
 
-      if (INT_ADD_OVERFLOW (overlay_heads.bytes, overlay_tails.bytes))
+      if (INT_ADD_WRAPV (overlay_heads.bytes, overlay_tails.bytes, &total))
         memory_full (SIZE_MAX);
-      total = overlay_heads.bytes + overlay_tails.bytes;
       if (total > overlay_str_len)
         overlay_str_buf = xpalloc (overlay_str_buf, &overlay_str_len,
                                    total - overlay_str_len, -1, 1);