Applying to trunk as obvious (explaining existing behavior).
-- 8< --
gcc/ChangeLog:
* doc/gty.texi: Add discussion of cache vs. deletable.
---
gcc/doc/gty.texi | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/gcc/doc/gty.texi b/gcc/doc/gty.texi
index 15f9fa07405..1dfe4652644 100644
--- a/gcc/doc/gty.texi
+++ b/gcc/doc/gty.texi
@@ -306,6 +306,13 @@ called on that variable between the mark and sweep phases
of garbage
collection. The gt_clear_cache function is free to mark blocks as used, or to
clear pointers in the variable.
+In a hash table, the @samp{gt_cleare_cache} function discards entries
+if the key is not marked, or marks the value if the key is marked.
+
+Note that caches should generally use @code{deletable} instead;
+@code{cache} is only preferable if the value is impractical to
+recompute from the key when needed.
+
@findex deletable
@item deletable
base-commit: 68845f7c4d58186cc0a5b09f7511f3c0a8f07e88
--
2.39.3
