Subject: Re: bug#59137: [PATCH] To minor changes related to overlays

From: Matt Armstrong <[email-masked]>
Date: Sat, 26 Nov 2022 11:37:18 -0800

Stefan Kangas <[email-masked]> writes:

> Stefan Monnier <[email-masked]> writes:
>
>>> Should these patches be installed?  Stefan?
>>
>> I don't have an opinion on the `itree_empty_p` patch, but the one about
>> `itree_iterator_finish` doesn't apply any more because
>> `itree_iterator_finish` has been removed in the mean time.
>
> Matt, if you think these patches are still relevant, could you please
> rebase them on top of current master?  Thanks in advance.

Hi Stefan and Stefan,

Attached is the rebased patch for the new helper function (it didn't
change much if at all).  As Stefan suggested, the patch for the iterator
is no longer relevant.

>From 3e2c4cd143d51c66198dd606e18015eeae42f3ec Mon Sep 17 00:00:00 2001
From: Matt Armstrong <[email-masked]>
Date: Tue, 8 Nov 2022 15:00:18 -0800
Subject: [PATCH] Add itree_empty_p for clarity and reduced coupling

* src/itree.h (itree_empty_p): New predicate.
* src/buffer.h (buffer_has_overlays): Call it.
* src/pdumper.c (dump_buffer): ditto.
* src/alloc.c (mark_buffer): ditto.
---
 src/alloc.c   | 2 +-
 src/buffer.h  | 3 +--
 src/itree.h   | 9 +++++++++
 src/pdumper.c | 2 +-
 4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/alloc.c b/src/alloc.c
index 0653f2e0cc..526a25393f 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -6553,7 +6553,7 @@ mark_buffer (struct buffer *buffer)
   if (!BUFFER_LIVE_P (buffer))
       mark_object (BVAR (buffer, undo_list));
 
-  if (buffer->overlays)
+  if (!itree_empty_p (buffer->overlays))
     mark_overlays (buffer->overlays->root);
 
   /* If this is an indirect buffer, mark its base buffer.  */
diff --git a/src/buffer.h b/src/buffer.h
index dded0cd98c..9ead875bcf 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -1277,8 +1277,7 @@ set_buffer_intervals (struct buffer *b, INTERVAL i)
 INLINE bool
 buffer_has_overlays (void)
 {
-  return current_buffer->overlays
-         && (current_buffer->overlays->root != NULL);
+  return !itree_empty_p (current_buffer->overlays);
 }
 
 /* Functions for accessing a character or byte,
diff --git a/src/itree.h b/src/itree.h
index 291fa53fd3..248ea9b84d 100644
--- a/src/itree.h
+++ b/src/itree.h
@@ -25,6 +25,8 @@ #define ITREE_H
 
 #include "lisp.h"
 
+INLINE_HEADER_BEGIN
+
 /* The tree and node structs are mainly here, so they can be
    allocated.
 
@@ -114,6 +116,11 @@ #define ITREE_H
 				   ptrdiff_t, ptrdiff_t);
 extern struct itree_tree *itree_create (void);
 extern void itree_destroy (struct itree_tree *);
+INLINE bool
+itree_empty_p (struct itree_tree *tree)
+{
+  return !tree || !tree->root;
+}
 extern intmax_t itree_size (struct itree_tree *);
 extern void itree_clear (struct itree_tree *);
 extern void itree_insert (struct itree_tree *, struct itree_node *,
@@ -178,4 +185,6 @@ #define ITREE_FOREACH(n, t, beg, end, order)                        \
 #define ITREE_FOREACH_NARROW(beg, end) \
   itree_iterator_narrow (itree_iter_, beg, end)
 
+INLINE_HEADER_END
+
 #endif
diff --git a/src/pdumper.c b/src/pdumper.c
index fedcd3e404..35e86d2b50 100644
--- a/src/pdumper.c
+++ b/src/pdumper.c
@@ -2863,7 +2863,7 @@ dump_buffer (struct dump_context *ctx, const struct buffer *in_buffer)
   DUMP_FIELD_COPY (out, buffer, inhibit_buffer_hooks);
   DUMP_FIELD_COPY (out, buffer, long_line_optimizations_p);
 
-  if (buffer->overlays && buffer->overlays->root != NULL)
+  if (!itree_empty_p (buffer->overlays))
     /* We haven't implemented the code to dump overlays.  */
     emacs_abort ();
   else
-- 
2.35.1