Parser cleanup: embed scanner in parser.

* parser.c (parser_destroy): New GC finalizer static function.
(parser_ops): Register parser_destroy.
(parser_common_init): New function, shared by parse and parse_once.
Initializes embedded scanner.
(parser_cleanup): New function, shared by parse_once and
parser_destroy.
(parser): Use parser_common_init.

* parser.h (parser_t): New member, yyscan.
(reset_scanner, parser_common_init): Declared.

* parser.l (reset_scanner): New function.

* parser.y (parse_once): Use parser_common_init, and
thus perform only a few initializations. Do not
define scanner as a local variable.
(parse): Call reset_scanner instead of
yylex_init since the scanner is being reused,
and for the same reason do not call yylex_destroy.
GC will do that now.

1 files changed, 4 insertions, 17 deletions

diff --git a/parser.y b/parser.y
index 12324f51..de3f600d 100644
--- a/parser.y
+++ b/parser.y
@@ -1443,22 +1443,15 @@ void yybadtoken(parser_t *parser, int tok, val context)
 int parse_once(val stream, val name, parser_t *parser)
 {
   int res;
-  yyscan_t scanner;
 
-  parser->lineno = 1;
-  parser->errors = 0;
+  parser_common_init(parser);
+
   parser->stream = stream;
   parser->name = name;
-  parser->prepared_msg = nil;
-  parser->syntax_tree = nil;
-  yylex_init(&scanner);
-  parser->scanner = convert(scanner_t *, scanner);
-
-  yyset_extra(parser, parser->scanner);
 
   res = yyparse(parser->scanner, parser);
 
-  yylex_destroy(parser->scanner);
+  parser_cleanup(parser);
 
   return res;
 }
@@ -1466,20 +1459,14 @@ int parse_once(val stream, val name, parser_t *parser)
 int parse(parser_t *parser)
 {
   int res;
-  yyscan_t scanner;
 
   parser->errors = 0;
   parser->prepared_msg = nil;
   parser->syntax_tree = nil;
   prime_parser(parser->parser);
-  yylex_init(&scanner);
-  parser->scanner = convert(scanner_t *, scanner);
-
-  yyset_extra(parser, parser->scanner);
+  reset_scanner(parser->scanner);
 
   res = yyparse(parser->scanner, parser);
 
-  yylex_destroy(parser->scanner);
-
   return res;
 }