Add symbol lookup cache.

gdb/ChangeLog:

	Add symbol lookup cache.
	* NEWS: Document new options and commands.
	* symtab.c (symbol_cache_key): New static global.
	(DEFAULT_SYMBOL_CACHE_SIZE, MAX_SYMBOL_CACHE_SIZE): New macros.
	(SYMBOL_LOOKUP_FAILED): New macro.
	(symbol_cache_slot_state): New enum.
	(block_symbol_cache): New struct.
	(symbol_cache): New struct.
	(new_symbol_cache_size, symbol_cache_size): New static globals.
	(hash_symbol_entry, eq_symbol_entry): New functions.
	(symbol_cache_byte_size, resize_symbol_cache): New functions.
	(make_symbol_cache, free_symbol_cache): New functions.
	(get_symbol_cache, symbol_cache_cleanup): New function.
	(set_symbol_cache_size, set_symbol_cache_size_handler): New functions.
	(symbol_cache_lookup, symbol_cache_clear_slot): New function.
	(symbol_cache_mark_found, symbol_cache_mark_not_found): New functions.
	(symbol_cache_flush, symbol_cache_dump): New functions.
	(maintenance_print_symbol_cache): New function.
	(maintenance_flush_symbol_cache): New function.
	(symbol_cache_stats): New function.
	(maintenance_print_symbol_cache_statistics): New function.
	(symtab_new_objfile_observer): New function.
	(symtab_free_objfile_observer): New function.
	(lookup_static_symbol, lookup_global_symbol): Use symbol cache.
	(_initialize_symtab): Init symbol_cache_key.  New parameter
	maint symbol-cache-size.  New maint commands print symbol-cache,
	print symbol-cache-statistics, flush-symbol-cache.
	Install new_objfile, free_objfile observers.

doc/ChangeLog:

	* gdb.texinfo (Symbols): Document new commands
	"maint print symbol-cache", "maint print symbol-cache-statistics",
	"maint flush-symbol-cache".  Document new option
	"maint set symbol-cache-size".

1 files changed, 13 insertions, 0 deletions

diff --git a/gdb/NEWS b/gdb/NEWS
index 9a668c4..f866a5a 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -57,6 +57,15 @@ add-auto-load-scripts-directory directory
 maint print user-registers
   List all currently available "user" registers.
 
+maint print symbol-cache
+  Print the contents of the symbol cache.
+
+maint print symbol-cache-statistics
+  Print statistics of symbol cache usage.
+
+maint flush-symbol-cache
+  Flush the contents of the symbol cache.
+
 compile code [-r|-raw] [--] [source code]
   Compile, inject, and execute in the inferior the executable object
   code produced by compiling the provided source code.
@@ -90,6 +99,10 @@ set debug symbol-lookup
 show debug symbol-lookup
   Control display of debugging info regarding symbol lookup.
 
+maint set symbol-cache-size
+maint show symbol-cache-size
+  Control the size of the symbol cache.
+
 * MI changes
 
   ** The -list-thread-groups command outputs an exit-code field for