[PATCH 1/2] destroy values as well as keys when removing them from hash maps

[tbsaunde+gcc@tbsaunde.org]

From: Trevor Saunders <tbsaunde+gcc@tbsaunde.org>

Hi,

This fixes several leaks where a hash_map user expected deleting the map to
destruct the value part of entries as well as the key.  A couple of these bugs
have already been fixed, but there are more of them for example some of the
sanitizer code, and tree-if-conv.c).  The expectation that hash_map should
destruct values seems to be pretty obviously correct, so we should fix that to
fix the existing bugs and prevent future ones (I also seem to remember that
working at some point, but could be incorrect).

I checked all the existing hash_map users and couldn't find any value types
other than auto_vec with destructors, so its the only one with a non trivial
destructor.  So the only effected case auto_vec is fixed by this patch and no
expectations are broken.

bootstrapped + regtested on x86_64-linux-gnu, ok?

Trev

gcc/ChangeLog:

2015-11-20  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* hash-map-traits.h (simple_hashmap_traits ::remove): call
	destructors on values that are being removed.
	* mem-stats.h (hash_map): Pass type of values to
	simple_hashmap_traits.
	* tree-sra.c (sra_deinitialize): Remove work around for hash
	maps not destructing values.
	* genmatch.c (sinfo_hashmap_traits): Adjust.
	* tree-ssa-uncprop.c (val_ssa_equiv_hash_traits): Likewise.
---
 gcc/genmatch.c         |  3 ++-
 gcc/hash-map-traits.h  | 32 +++++++++++++++++---------------
 gcc/mem-stats.h        |  3 ++-
 gcc/tree-sra.c         |  6 ------
 gcc/tree-ssa-uncprop.c |  3 ++-
 5 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/gcc/genmatch.c b/gcc/genmatch.c
index 3a20a48..76c8f1f 100644
--- a/gcc/genmatch.c
+++ b/gcc/genmatch.c
@@ -1397,7 +1397,8 @@ struct sinfo
   unsigned cnt;
 };
 
-struct sinfo_hashmap_traits : simple_hashmap_traits <pointer_hash <dt_simplify> >
+struct sinfo_hashmap_traits : simple_hashmap_traits<pointer_hash<dt_simplify>,
+						    sinfo *>
 {
   static inline hashval_t hash (const key_type &);
   static inline bool equal_keys (const key_type &, const key_type &);
diff --git a/gcc/hash-map-traits.h b/gcc/hash-map-traits.h
index 2225426..773ac1b 100644
--- a/gcc/hash-map-traits.h
+++ b/gcc/hash-map-traits.h
@@ -28,7 +28,7 @@ along with GCC; see the file COPYING3.  If not see
 /* Implement hash_map traits for a key with hash traits H.  Empty and
    deleted map entries are represented as empty and deleted keys.  */
 
-template <typename H>
+template <typename H, typename Value>
 struct simple_hashmap_traits
 {
   typedef typename H::value_type key_type;
@@ -41,56 +41,58 @@ struct simple_hashmap_traits
   template <typename T> static inline void mark_deleted (T &);
 };
 
-template <typename H>
+template <typename H, typename Value>
 inline hashval_t
-simple_hashmap_traits <H>::hash (const key_type &h)
+simple_hashmap_traits <H, Value>::hash (const key_type &h)
 {
   return H::hash (h);
 }
 
-template <typename H>
+template <typename H, typename Value>
 inline bool
-simple_hashmap_traits <H>::equal_keys (const key_type &k1, const key_type &k2)
+simple_hashmap_traits <H, Value>::equal_keys (const key_type &k1,
+					      const key_type &k2)
 {
   return H::equal (k1, k2);
 }
 
-template <typename H>
+template <typename H, typename Value>
 template <typename T>
 inline void
-simple_hashmap_traits <H>::remove (T &entry)
+simple_hashmap_traits <H, Value>::remove (T &entry)
 {
   H::remove (entry.m_key);
+  entry.m_value.~Value ();
 }
 
-template <typename H>
+template <typename H, typename Value>
 template <typename T>
 inline bool
-simple_hashmap_traits <H>::is_empty (const T &entry)
+simple_hashmap_traits <H, Value>::is_empty (const T &entry)
 {
   return H::is_empty (entry.m_key);
 }
 
-template <typename H>
+template <typename H, typename Value>
 template <typename T>
 inline bool
-simple_hashmap_traits <H>::is_deleted (const T &entry)
+simple_hashmap_traits <H, Value>::is_deleted (const T &entry)
 {
   return H::is_deleted (entry.m_key);
 }
 
-template <typename H>
+template <typename H, typename Value>
 template <typename T>
 inline void
-simple_hashmap_traits <H>::mark_empty (T &entry)
+simple_hashmap_traits <H, Value>::mark_empty (T &entry)
 {
   H::mark_empty (entry.m_key);
 }
 
-template <typename H>
+template <typename H, typename Value>
 template <typename T>
 inline void
-simple_hashmap_traits <H>::mark_deleted (T &entry)
+simple_hashmap_traits <H, Value>::mark_deleted (T &entry)
 {
   H::mark_deleted (entry.m_key);
 }
diff --git a/gcc/mem-stats.h b/gcc/mem-stats.h
index a6489b5..2c68ca7 100644
--- a/gcc/mem-stats.h
+++ b/gcc/mem-stats.h
@@ -3,7 +3,8 @@
 
 /* Forward declaration.  */
 template<typename Key, typename Value,
-	 typename Traits = simple_hashmap_traits<default_hash_traits<Key> > >
+	 typename Traits = simple_hashmap_traits<default_hash_traits<Key>,
+						 Value> >
 class hash_map;
 
 #define LOCATION_LINE_EXTRA_SPACE 30
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 2835c99..c4fea5b 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -674,12 +674,6 @@ sra_deinitialize (void)
   assign_link_pool.release ();
   obstack_free (&name_obstack, NULL);
 
-  /* TODO: hash_map does not support traits that can release
-     value type of the hash_map.  */
-  for (hash_map<tree, auto_vec<access_p> >::iterator it =
-       base_access_vec->begin (); it != base_access_vec->end (); ++it)
-    (*it).second.release ();
-
   delete base_access_vec;
 }
 
diff --git a/gcc/tree-ssa-uncprop.c b/gcc/tree-ssa-uncprop.c
index be6c209d..23b4ca2 100644
--- a/gcc/tree-ssa-uncprop.c
+++ b/gcc/tree-ssa-uncprop.c
@@ -277,7 +277,8 @@ struct equiv_hash_elt
 
 /* Value to ssa name equivalence hashtable helpers.  */
 
-struct val_ssa_equiv_hash_traits : simple_hashmap_traits <tree_operand_hash>
+struct val_ssa_equiv_hash_traits : simple_hashmap_traits <tree_operand_hash,
+							  vec<tree> >
 {
   template<typename T> static inline void remove (T &);
 };
-- 
2.4.0