split parser initialisation from parser execution

p4raw-id: //depot/perl@29652

6 files changed, 34 insertions, 21 deletions

diff --git a/embed.fnc b/embed.fnc
index 0294389002..36d57e647a 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -956,6 +956,7 @@ p	|void	|write_to_stderr|NN const char* message|int msglen
 p	|int	|yyerror	|NN const char* s
 p	|int	|yylex
 p	|int	|yyparse
+p	|void	|parser_free	|NN const yy_parser *
 p	|int	|yywarn		|NN const char* s
 #if defined(MYMALLOC)
 Ap	|void	|dump_mstats	|NN char* s
diff --git a/embed.h b/embed.h
index f2fa696e01..d948188329 100644
--- a/embed.h
+++ b/embed.h
@@ -976,6 +976,7 @@
 #define yyerror			Perl_yyerror
 #define yylex			Perl_yylex
 #define yyparse			Perl_yyparse
+#define parser_free		Perl_parser_free
 #define yywarn			Perl_yywarn
 #endif
 #if defined(MYMALLOC)
@@ -3183,6 +3184,7 @@
 #define yyerror(a)		Perl_yyerror(aTHX_ a)
 #define yylex()			Perl_yylex(aTHX)
 #define yyparse()		Perl_yyparse(aTHX)
+#define parser_free(a)		Perl_parser_free(aTHX_ a)
 #define yywarn(a)		Perl_yywarn(aTHX_ a)
 #endif
 #if defined(MYMALLOC)
diff --git a/parser.h b/parser.h
index 9a61a52164..89d1c6cdaf 100644
--- a/parser.h
+++ b/parser.h
@@ -9,6 +9,8 @@
  * and lexer (perly.c, toke,c).
  */
 
+#define YYEMPTY		(-2)
+
 typedef struct {
     YYSTYPE val;    /* semantic value */
     short   state;
diff --git a/perly.c b/perly.c
index bf239fa0d4..36f78a346b 100644
--- a/perly.c
+++ b/perly.c
@@ -45,7 +45,6 @@ typedef signed char yysigned_char;
 
 # define YYSIZE_T size_t
 
-#define YYEMPTY		(-2)
 #define YYEOF		0
 #define YYTERROR	1
 
@@ -187,9 +186,6 @@ do {					\
 #  define YY_REDUCE_PRINT(Rule)
 #endif /* !DEBUGGING */
 
-/* YYINITDEPTH -- initial size of the parser's stacks.  */
-#define YYINITDEPTH 200
-
 /* called during cleanup (via SAVEDESTRUCTOR_X) to free any items on the
  * parse stack, thus avoiding leaks if we die  */
 
@@ -300,8 +296,8 @@ S_clear_yystack(pTHX_  const yy_parser *parser)
 
 /* delete a parser object */
 
-static void
-S_parser_free(pTHX_  const yy_parser *parser)
+void
+Perl_parser_free(pTHX_  const yy_parser *parser)
 {
     S_clear_yystack(aTHX_ parser);
     Safefree(parser->stack);
@@ -334,7 +330,7 @@ Perl_yyparse (pTHX)
 #define YYPOPSTACK   parser->ps = --ps
 #define YYPUSHSTACK  parser->ps = ++ps
 
-    /* The variables used to return semantic value and location from the
+    /* The variable used to return semantic value and location from the
 	  action routines: ie $$.  */
     YYSTYPE yyval;
 
@@ -347,22 +343,11 @@ Perl_yyparse (pTHX)
 
     YYDPRINTF ((Perl_debug_log, "Starting parse\n"));
 
-    Newx(parser, 1, yy_parser);
-    parser->old_parser = PL_parser;
-    PL_parser = parser;
-
-    Newx(ps, YYINITDEPTH, yy_stack_frame);
-    parser->stack = ps;
-    parser->ps = ps;
-    parser->stack_size = YYINITDEPTH;
+    parser = PL_parser;
+    ps = parser->ps;
 
     ENTER;  /* force parser free before we return */
-    SAVEDESTRUCTOR_X(S_parser_free, (void*) parser);
-
-
-    ps->state = 0;
-    parser->yyerrstatus = 0;
-    parser->yychar = YYEMPTY;		/* Cause a token to be read.  */
+    SAVEDESTRUCTOR_X(Perl_parser_free, (void*) parser);
 
 /*------------------------------------------------------------.
 | yynewstate -- Push a new state, which is found in yystate.  |
diff --git a/proto.h b/proto.h
index 23e5857597..27f830bf25 100644
--- a/proto.h
+++ b/proto.h
@@ -2597,6 +2597,9 @@ PERL_CALLCONV int	Perl_yyerror(pTHX_ const char* s)
 
 PERL_CALLCONV int	Perl_yylex(pTHX);
 PERL_CALLCONV int	Perl_yyparse(pTHX);
+PERL_CALLCONV void	Perl_parser_free(pTHX_ const yy_parser *)
+			__attribute__nonnull__(pTHX_1);
+
 PERL_CALLCONV int	Perl_yywarn(pTHX_ const char* s)
 			__attribute__nonnull__(pTHX_1);
 
diff --git a/toke.c b/toke.c
index 7277d89933..db265b3720 100644
--- a/toke.c
+++ b/toke.c
@@ -25,6 +25,9 @@
 
 #define yylval	(PL_parser->yylval)
 
+/* YYINITDEPTH -- initial size of the parser's stacks.  */
+#define YYINITDEPTH 200
+
 static const char ident_too_long[] = "Identifier too long";
 static const char commaless_variable_list[] = "comma-less variable list";
 
@@ -580,6 +583,23 @@ Perl_lex_start(pTHX_ SV *line)
     dVAR;
     const char *s;
     STRLEN len;
+    yy_parser *parser;
+
+    /* create and initialise a parser */
+
+    Newx(parser, 1, yy_parser);
+    parser->old_parser = PL_parser;
+    PL_parser = parser;
+
+    Newx(parser->stack, YYINITDEPTH, yy_stack_frame);
+    parser->ps = parser->stack;
+    parser->stack_size = YYINITDEPTH;
+
+    parser->stack->state = 0;
+    parser->yyerrstatus = 0;
+    parser->yychar = YYEMPTY;		/* Cause a token to be read.  */
+
+    /* initialise lexer state */
 
     SAVEI32(PL_lex_dojoin);
     SAVEI32(PL_lex_brackets);