gdb: turn gdb::bcache's function pointers into virtual methods

The two function pointers optionally passed to gdb::bcache are very good
candidates to be turned into virtual methods, this patch does that in
the most straightforward / unsurprising way.

gdb/ChangeLog:

	* bcache.h (struct bcache) <bcache>: Remove constructor.
	<m_hash_function, m_compare_function>: Remove.
	<~bcache>: Make virtual.
	<compare>: Remove static method, introduce virtual method.
	<default_hash>: Remove.
	<hash>: New virtual method.
	* bcache.c (bcache::expand_hash_table): Update.
	(bcache::insert): Update.
	(bcache::hash): New.
	(bcache::compare): Update comment and parameter names.
	* gdbtypes.c (types_deeply_equal): Update.
	* psymtab.h (struct psymbol_bcache): New struct.
	(class psymtab_storage) <psymtab_storage>: Make default.
	<psymbol_cache>: Change type to psymbol_bcache.
	* psymtab.c (psymtab_storage::psymtab_storage): Remove.
	(psymbol_hash): Change to...
	(psymbol_bcache::hash): ... this.
	(psymbol_compare): Change to...
	(psymbol_bcache::compare): ... this.

Change-Id: I41d578e61de8ac1163461a28fbd220d1f855e372

1 files changed, 11 insertions, 30 deletions

diff --git a/gdb/bcache.h b/gdb/bcache.h
index d8b18dc..b92989f 100644
--- a/gdb/bcache.h
+++ b/gdb/bcache.h
@@ -142,21 +142,7 @@ struct bstring;
 
 struct bcache
 {
-  /* Allocate a bcache.  HASH_FN and COMPARE_FN can be used to pass in
-     custom hash, and compare functions to be used by this bcache.  If
-     HASH_FUNCTION is NULL fast_hash() is used and if COMPARE_FUNCTION is
-     NULL memcmp() is used.  */
-
-  explicit bcache (unsigned long (*hash_fn)(const void *,
-					    int length) = nullptr,
-		   int (*compare_fn)(const void *, const void *,
-				     int length) = nullptr)
-    : m_hash_function (hash_fn == nullptr ? default_hash : hash_fn),
-      m_compare_function (compare_fn == nullptr ? compare : compare_fn)
-  {
-  }
-
-  ~bcache ();
+  virtual ~bcache ();
 
   /* Find a copy of the LENGTH bytes at ADDR in BCACHE.  If BCACHE has
      never seen those bytes before, add a copy of them to BCACHE.  In
@@ -175,6 +161,16 @@ struct bcache
   void print_statistics (const char *type);
   int memory_used ();
 
+protected:
+
+  /* Hash function to be used for this bcache object.  Defaults to
+     fast_hash.  */
+  virtual unsigned long hash (const void *addr, int length);
+
+  /* Compare function to be used for this bcache object.  Defaults to
+     memcmp.  */
+  virtual int compare (const void *left, const void *right, int length);
+
 private:
 
   /* All the bstrings are allocated here.  */
@@ -205,21 +201,6 @@ private:
      length/data compare missed.  */
   unsigned long m_half_hash_miss_count = 0;
 
-  /* Hash function to be used for this bcache object.  */
-  unsigned long (*m_hash_function)(const void *addr, int length);
-
-  /* Compare function to be used for this bcache object.  */
-  int (*m_compare_function)(const void *, const void *, int length);
-
-  /* Default compare function.  */
-  static int compare (const void *addr1, const void *addr2, int length);
-
-  /* Default hash function.  */
-  static unsigned long default_hash (const void *ptr, int length)
-  {
-    return fast_hash (ptr, length, 0);
-  }
-
   /* Expand the hash table.  */
   void expand_hash_table ();
 };