Use INT_ADD_WRAPV etc. to check integer overflow

[gnu-emacs] / src / dispnew.c

diff --git a/src/dispnew.c b/src/dispnew.c
index 1a822f0636504e959b4c3fd0b5bdbfae76691ba6..64c84aec6f9319217a71bd790d24f90e28295aa4 100644 (file)
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -1331,10 +1331,8 @@ realloc_glyph_pool (struct glyph_pool *pool, struct dim matrix_dim)
               || matrix_dim.width != pool->ncolumns);
 
   /* Enlarge the glyph pool.  */
-  needed = matrix_dim.width;
-  if (INT_MULTIPLY_OVERFLOW (needed, matrix_dim.height))
+  if (INT_MULTIPLY_WRAPV (matrix_dim.height, matrix_dim.width, &needed))
     memory_full (SIZE_MAX);
-  needed *= matrix_dim.height;
   if (needed > pool->nglyphs)
     {
       ptrdiff_t old_nglyphs = pool->nglyphs;
@@ -6094,15 +6092,15 @@ init_display (void)
     struct frame *sf = SELECTED_FRAME ();
     int width = FRAME_TOTAL_COLS (sf);
     int height = FRAME_TOTAL_LINES (sf);
+    int area;
 
     /* If these sizes are so big they cause overflow, just ignore the
        change.  It's not clear what better we could do.  The rest of
        the code assumes that (width + 2) * height * sizeof (struct glyph)
        does not overflow and does not exceed PTRDIFF_MAX or SIZE_MAX.  */
-    if (INT_ADD_OVERFLOW (width, 2)
-       || INT_MULTIPLY_OVERFLOW (width + 2, height)
-       || (min (PTRDIFF_MAX, SIZE_MAX) / sizeof (struct glyph)
-           < (width + 2) * height))
+    if (INT_ADD_WRAPV (width, 2, &area)
+       || INT_MULTIPLY_WRAPV (height, area, &area)
+       || min (PTRDIFF_MAX, SIZE_MAX) / sizeof (struct glyph) < area)
       fatal ("screen size %dx%d too big", width, height);
   }