Change hash_table to support a comparator type different from the value type stored in the hash table.

Change hash_table to support a comparator type different from the
value type stored in the hash table.  The 'find' functions now may
take a different type from the value type.  This requires introducing
a second typedef into the Descriptor conceptual type.  Change the
Descriptor concept to use typedefs value_type and compare_type instead
of T.  Change all users to match.

Add usage documentation to hash-table.h.

Tested on x86-64.


Index: gcc/ChangeLog

2012-10-25  Lawrence Crowl  <crowl@google.com>

	* hash-table.h: Add usage documentation.
	(template struct typed_free_remove): Clarify documentation. 
	Rename template parameter.
	(struct typed_noop_remove): Likewise.
	(descriptor concept): Change typedef T to value_type.
	Add typedef compare_type.  Use more precise template parameter name,
	Descriptor instead of Descr.  Update users to match.
	(struct hash_table): Change 'find' parameters to use compare_type
	instead of the value type.

From-SVN: r192823

1 files changed, 9 insertions, 8 deletions

diff --git a/gcc/coverage.c b/gcc/coverage.c
index f9b12e8..b634c82 100644
--- a/gcc/coverage.c
+++ b/gcc/coverage.c
@@ -79,10 +79,11 @@ typedef struct counts_entry
   struct gcov_ctr_summary summary;
 
   /* hash_table support.  */
-  typedef counts_entry T;
-  static inline hashval_t hash (const counts_entry *);
-  static int equal (const counts_entry *, const counts_entry *);
-  static void remove (counts_entry *);
+  typedef counts_entry value_type;
+  typedef counts_entry compare_type;
+  static inline hashval_t hash (const value_type *);
+  static int equal (const value_type *, const compare_type *);
+  static void remove (value_type *);
 } counts_entry_t;
 
 static GTY(()) struct coverage_data *functions_head = 0;
@@ -150,20 +151,20 @@ get_gcov_unsigned_t (void)
 }
 
 inline hashval_t
-counts_entry::hash (const counts_entry_t *entry)
+counts_entry::hash (const value_type *entry)
 {
   return entry->ident * GCOV_COUNTERS + entry->ctr;
 }
 
 inline int
-counts_entry::equal (const counts_entry_t *entry1,
-		     const counts_entry_t *entry2)
+counts_entry::equal (const value_type *entry1,
+		     const compare_type *entry2)
 {
   return entry1->ident == entry2->ident && entry1->ctr == entry2->ctr;
 }
 
 inline void
-counts_entry::remove (counts_entry_t *entry)
+counts_entry::remove (value_type *entry)
 {
   free (entry->counts);
   free (entry);