[PATCH] Fix leak in splay-tree

[PATCH] Fix leak in splay-tree

[Tom Tromey]

Philippe Waroquiers noticed a memory leak in gdb, which he tracked
down to a bug in splay-tree.  splay_tree_remove does not call the
`delete_key' function when it removes the old node; but it should.

I looked at every splay tree in GCC and there is only one that passes
a non-NULL delete function -- the one in lto.c.  That file does not
call splay_tree_remove.  So, I think this is safe to check in.

I re-ran the LTO tests to double check.

libiberty/
	* splay-tree.c (splay_tree_remove): Delete the key if necessary.
---
 libiberty/ChangeLog    | 4 ++++
 libiberty/splay-tree.c | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
index bcc0227bdd8..1eb25f928f2 100644
--- a/libiberty/ChangeLog
+++ b/libiberty/ChangeLog
@@ -1,3 +1,7 @@
+2019-01-18  Tom Tromey  <tom@tromey.com>
+
+	* splay-tree.c (splay_tree_remove): Delete the key if necessary.
+
 2019-01-14  Tom Honermann  <tom@honermann.net>
 
 	* cp-demangle.c (cplus_demangle_builtin_types)
diff --git a/libiberty/splay-tree.c b/libiberty/splay-tree.c
index 920e68db2cb..21d23c38dfc 100644
--- a/libiberty/splay-tree.c
+++ b/libiberty/splay-tree.c
@@ -425,6 +425,8 @@ splay_tree_remove (splay_tree sp, splay_tree_key key)
       right = sp->root->right;
 
       /* Delete the root node itself.  */
+      if (sp->delete_key)
+	(*sp->delete_key) (sp->root->key);
       if (sp->delete_value)
 	(*sp->delete_value) (sp->root->value);
       (*sp->deallocate) (sp->root, sp->allocate_data);
-- 
2.17.2

Re: [PATCH] Fix leak in splay-tree

[Richard Biener]

On Fri, Jan 18, 2019 at 10:27 PM Tom Tromey <tom@tromey.com> wrote:
>
> Philippe Waroquiers noticed a memory leak in gdb, which he tracked
> down to a bug in splay-tree.  splay_tree_remove does not call the
> `delete_key' function when it removes the old node; but it should.
>
> I looked at every splay tree in GCC and there is only one that passes
> a non-NULL delete function -- the one in lto.c.  That file does not
> call splay_tree_remove.  So, I think this is safe to check in.
>
> I re-ran the LTO tests to double check.

OK

> libiberty/
>         * splay-tree.c (splay_tree_remove): Delete the key if necessary.
> ---
>  libiberty/ChangeLog    | 4 ++++
>  libiberty/splay-tree.c | 2 ++
>  2 files changed, 6 insertions(+)
>
> diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog
> index bcc0227bdd8..1eb25f928f2 100644
> --- a/libiberty/ChangeLog
> +++ b/libiberty/ChangeLog
> @@ -1,3 +1,7 @@
> +2019-01-18  Tom Tromey  <tom@tromey.com>
> +
> +       * splay-tree.c (splay_tree_remove): Delete the key if necessary.
> +
>  2019-01-14  Tom Honermann  <tom@honermann.net>
>
>         * cp-demangle.c (cplus_demangle_builtin_types)
> diff --git a/libiberty/splay-tree.c b/libiberty/splay-tree.c
> index 920e68db2cb..21d23c38dfc 100644
> --- a/libiberty/splay-tree.c
> +++ b/libiberty/splay-tree.c
> @@ -425,6 +425,8 @@ splay_tree_remove (splay_tree sp, splay_tree_key key)
>        right = sp->root->right;
>
>        /* Delete the root node itself.  */
> +      if (sp->delete_key)
> +       (*sp->delete_key) (sp->root->key);
>        if (sp->delete_value)
>         (*sp->delete_value) (sp->root->value);
>        (*sp->deallocate) (sp->root, sp->allocate_data);
> --
> 2.17.2
>