Take last_per_buffer_idx private

This will simplify future changes.  Turn the runtime check
into an eassert, since it’s not needed in production.
* src/buffer.c (last_per_buffer_idx): Now static.
(valid_per_buffer_idx): New function.
* src/buffer.h (PER_BUFFER_VALUE_P, SET_PER_BUFFER_VALUE_P): Use it.

2 files changed, 13 insertions, 13 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 62a3d66c8b7..77e8b6bb779 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -105,7 +105,7 @@ static char buffer_permanent_local_flags[MAX_PER_BUFFER_VARS];
 
 /* Number of per-buffer variables used.  */
 
-int last_per_buffer_idx;
+static int last_per_buffer_idx;
 
 static void call_overlay_mod_hooks (Lisp_Object list, Lisp_Object overlay,
                                     bool after, Lisp_Object arg1,
@@ -655,6 +655,12 @@ set_buffer_overlays_after (struct buffer *b, struct Lisp_Overlay *o)
   b->overlays_after = o;
 }
 
+bool
+valid_per_buffer_idx (int idx)
+{
+  return 0 <= idx && idx < last_per_buffer_idx;
+}
+
 /* Clone per-buffer values of buffer FROM.
 
    Buffer TO gets the same per-buffer values as FROM, with the
diff --git a/src/buffer.h b/src/buffer.h
index 2080a6f40b7..14de70c6482 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1268,10 +1268,6 @@ buffer_window_count (struct buffer *b)
                         Buffer-local Variables
  ***********************************************************************/
 
-/* Number of per-buffer variables used.  */
-
-extern int last_per_buffer_idx;
-
 /* Return the offset in bytes of member VAR of struct buffer
    from the start of a buffer structure.  */
 
@@ -1296,23 +1292,21 @@ extern int last_per_buffer_idx;
 #define PER_BUFFER_VAR_IDX(VAR) \
     PER_BUFFER_IDX (PER_BUFFER_VAR_OFFSET (VAR))
 
+extern bool valid_per_buffer_idx (int);
+
 /* Value is true if the variable with index IDX has a local value
    in buffer B.  */
 
 #define PER_BUFFER_VALUE_P(B, IDX)              \
-    (((IDX) < 0 || IDX >= last_per_buffer_idx)  \
-     ? (emacs_abort (), false)                  \
-     : ((B)->local_flags[IDX] != 0))
+  (eassert (valid_per_buffer_idx (IDX)),        \
+   (B)->local_flags[IDX])
 
 /* Set whether per-buffer variable with index IDX has a buffer-local
    value in buffer B.  VAL zero means it hasn't.  */
 
 #define SET_PER_BUFFER_VALUE_P(B, IDX, VAL)     \
-     do {                                               \
-       if ((IDX) < 0 || (IDX) >= last_per_buffer_idx)   \
-         emacs_abort ();                                \
-       (B)->local_flags[IDX] = (VAL);                   \
-     } while (false)
+  (eassert (valid_per_buffer_idx (IDX)),        \
+   (B)->local_flags[IDX] = (VAL))
 
 /* Return the index value of the per-buffer variable at offset OFFSET
    in the buffer structure.