From e20773049fde7b9a123fda4485259fc06249b22f Mon Sep 17 00:00:00 2001 From: tromey Date: Tue, 12 Feb 2019 13:02:48 +0000 Subject: [PATCH] Fix splay tree KEY leak detected in GDB test gdb.base/macscp.exp When a node is removed from a splay tree, the splay tree was not using the function splay_tree_delete_key_fn to release the key. This was causing a leak, fixed by Tom Tromey. This patch fixes another key leak, that happens when a key equal to a key already present is inserted. In such a case, we have to release the old KEY. Note that this is based on the assumption that the caller always allocates a new KEY when doing an insert. Also, clarify the documentation about when the release functions are called. 2019-02-11 Philippe Waroquiers * splay-tree.h (splay_tree_delete_key_fn): Update comment. (splay_tree_delete_value_fn): Likewise. libiberty/ChangeLog 2019-02-11 Philippe Waroquiers * splay-tree.c (splay_tree_insert): Also release old KEY in case of insertion of a key equal to an already present key. (splay_tree_new_typed_alloc): Update comment. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@268793 138bc75d-0d04-0410-961f-82ee72b054a4 --- include/ChangeLog | 5 +++++ include/splay-tree.h | 11 +++++++++-- libiberty/ChangeLog | 6 ++++++ libiberty/splay-tree.c | 13 ++++++++++--- 4 files changed, 30 insertions(+), 5 deletions(-) diff --git a/include/ChangeLog b/include/ChangeLog index a88efc2231c..2a71eee451a 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,8 @@ +2019-02-11 Philippe Waroquiers + + * splay-tree.h (splay_tree_delete_key_fn): Update comment. + (splay_tree_delete_value_fn): Likewise. + 2019-01-31 Andreas Krebbel * opcode/s390.h (enum s390_opcode_cpu_val): Add diff --git a/include/splay-tree.h b/include/splay-tree.h index 0d262729435..da533dec183 100644 --- a/include/splay-tree.h +++ b/include/splay-tree.h @@ -58,11 +58,18 @@ typedef struct splay_tree_node_s *splay_tree_node; typedef int (*splay_tree_compare_fn) (splay_tree_key, splay_tree_key); /* The type of a function used to deallocate any resources associated - with the key. */ + with the key. If you provide this function, the splay tree + will take the ownership of the memory of the splay_tree_key arg + of splay_tree_insert. This function is called to release the keys + present in the tree when calling splay_tree_delete or splay_tree_remove. + If splay_tree_insert is called with a key equal to a key already + present in the tree, the old key and old value will be released. */ typedef void (*splay_tree_delete_key_fn) (splay_tree_key); /* The type of a function used to deallocate any resources associated - with the value. */ + with the value. If you provide this function, the memory of the + splay_tree_value arg of splay_tree_insert is managed similarly to + the splay_tree_key memory: see splay_tree_delete_key_fn. */ typedef void (*splay_tree_delete_value_fn) (splay_tree_value); /* The type of a function used to iterate over the tree. */ diff --git a/libiberty/ChangeLog b/libiberty/ChangeLog index 496d76d3ff4..c9ff317b6fd 100644 --- a/libiberty/ChangeLog +++ b/libiberty/ChangeLog @@ -1,3 +1,9 @@ +2019-02-11 Philippe Waroquiers + + * splay-tree.c (splay_tree_insert): Also release old KEY in case + of insertion of a key equal to an already present key. + (splay_tree_new_typed_alloc): Update comment. + 2019-01-21 Tom Tromey * splay-tree.c (splay_tree_remove): Delete the key if necessary. diff --git a/libiberty/splay-tree.c b/libiberty/splay-tree.c index 21d23c38dfc..4bbb39a62ca 100644 --- a/libiberty/splay-tree.c +++ b/libiberty/splay-tree.c @@ -318,7 +318,11 @@ different types need to be allocated with different allocators. The splay tree will use @var{compare_fn} to compare nodes, @var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to -deallocate values. +deallocate values. Keys and values will be deallocated when the +tree is deleted using splay_tree_delete or when a node is removed +using splay_tree_remove. splay_tree_insert will release the previously +inserted key and value using @var{delete_key_fn} and @var{delete_value_fn} +if the inserted key is already found in the tree. @end deftypefn @@ -372,10 +376,13 @@ splay_tree_insert (splay_tree sp, splay_tree_key key, splay_tree_value value) if (sp->root && comparison == 0) { - /* If the root of the tree already has the indicated KEY, just - replace the value with VALUE. */ + /* If the root of the tree already has the indicated KEY, delete + the old key and old value, and replace them with KEY and VALUE. */ + if (sp->delete_key) + (*sp->delete_key) (sp->root->key); if (sp->delete_value) (*sp->delete_value)(sp->root->value); + sp->root->key = key; sp->root->value = value; } else -- 2.30.2