gst/parse/: Make the parser reentrant and recursively callable. This requires flex >= 2.5.31, for older versions preg...

Original commit message from CVS:
Patch by: Marc-Andre Lureau <marcandre dot lureau at gmail dot com>
* gst/parse/Makefile.am:
* gst/parse/grammar.y:
* gst/parse/parse.l:
Make the parser reentrant and recursively callable. This requires flex
>= 2.5.31, for older versions pregenerated sources are used as we
can't bump the build dependency. Finally fixes #349180.
* gst/gstparse.c: (gst_parse_launch):
Drop the HAVE_MT_SAVE_FLEX #ifdefs as we always use a new enough flex
now anyway.
* docs/gst/Makefile.am:
* docs/gst/Makefile.am:
* gst/parse/grammar.tab.pre.c: (__gst_parse_strdup),
(__gst_parse_strfree), (__gst_parse_link_new),
(__gst_parse_link_free), (__gst_parse_chain_new),
(__gst_parse_chain_free), (SET_ERROR), (YYPRINTF),
(gst_parse_element_set), (gst_parse_free_link),
(gst_parse_found_pad), (gst_parse_perform_delayed_link),
(gst_parse_perform_link), (yytnamerr), (yysyntax_error), (yyerror),
(_gst_parse_launch):
* gst/parse/grammar.tab.pre.h:
* gst/parse/lex._gst_parse_yy.pre.c: (PRINT), (yy_get_next_buffer),
(yy_get_previous_state), (yy_try_NUL_trans), (input),
(_gst_parse_yyrestart), (_gst_parse_yy_switch_to_buffer),
(_gst_parse_yy_load_buffer_state), (_gst_parse_yy_create_buffer),
(_gst_parse_yy_delete_buffer), (_gst_parse_yy_init_buffer),
(_gst_parse_yy_flush_buffer), (_gst_parse_yypush_buffer_state),
(_gst_parse_yypop_buffer_state),
(_gst_parse_yyensure_buffer_stack), (_gst_parse_yy_scan_buffer),
(_gst_parse_yy_scan_string), (_gst_parse_yy_scan_bytes),
(yy_fatal_error), (_gst_parse_yyget_extra),
(_gst_parse_yyget_lineno), (_gst_parse_yyget_column),
(_gst_parse_yyget_in), (_gst_parse_yyget_out),
(_gst_parse_yyget_leng), (_gst_parse_yyget_text),
(_gst_parse_yyset_extra), (_gst_parse_yyset_lineno),
(_gst_parse_yyset_column), (_gst_parse_yyset_in),
(_gst_parse_yyset_out), (_gst_parse_yyget_debug),
(_gst_parse_yyset_debug), (_gst_parse_yyget_lval),
(_gst_parse_yyset_lval), (_gst_parse_yylex_init),
(yy_init_globals), (_gst_parse_yylex_destroy), (yy_flex_strncpy),
(yy_flex_strlen), (_gst_parse_yyalloc), (_gst_parse_yyrealloc),
(_gst_parse_yyfree):
If the installed flex version is too old use pre-generated parser
sources. These pre-generated parser sources are always updated when
the actual flex/bison sources change but require everybody who wants
to change something in the parser to have flex >= 2.5.31 installed.

ChangeLog

@@ -1,3 +1,54 @@
+2007-04-18  Sebastian Dröge  <slomo@circular-chaos.org>
+
+	Patch by: Marc-Andre Lureau <marcandre dot lureau at gmail dot com>
+	* gst/parse/Makefile.am:
+	* gst/parse/grammar.y:
+	* gst/parse/parse.l:
+	Make the parser reentrant and recursively callable. This requires flex
+	>= 2.5.31, for older versions pregenerated sources are used as we
+	can't bump the build dependency. Finally fixes #349180.
+
+	* gst/gstparse.c: (gst_parse_launch):
+	Drop the HAVE_MT_SAVE_FLEX #ifdefs as we always use a new enough flex
+	now anyway.
+
+	* docs/gst/Makefile.am:
+	* docs/gst/Makefile.am:
+	* gst/parse/grammar.tab.pre.c: (__gst_parse_strdup),
+	(__gst_parse_strfree), (__gst_parse_link_new),
+	(__gst_parse_link_free), (__gst_parse_chain_new),
+	(__gst_parse_chain_free), (SET_ERROR), (YYPRINTF),
+	(gst_parse_element_set), (gst_parse_free_link),
+	(gst_parse_found_pad), (gst_parse_perform_delayed_link),
+	(gst_parse_perform_link), (yytnamerr), (yysyntax_error), (yyerror),
+	(_gst_parse_launch):
+	* gst/parse/grammar.tab.pre.h:
+	* gst/parse/lex._gst_parse_yy.pre.c: (PRINT), (yy_get_next_buffer),
+	(yy_get_previous_state), (yy_try_NUL_trans), (input),
+	(_gst_parse_yyrestart), (_gst_parse_yy_switch_to_buffer),
+	(_gst_parse_yy_load_buffer_state), (_gst_parse_yy_create_buffer),
+	(_gst_parse_yy_delete_buffer), (_gst_parse_yy_init_buffer),
+	(_gst_parse_yy_flush_buffer), (_gst_parse_yypush_buffer_state),
+	(_gst_parse_yypop_buffer_state),
+	(_gst_parse_yyensure_buffer_stack), (_gst_parse_yy_scan_buffer),
+	(_gst_parse_yy_scan_string), (_gst_parse_yy_scan_bytes),
+	(yy_fatal_error), (_gst_parse_yyget_extra),
+	(_gst_parse_yyget_lineno), (_gst_parse_yyget_column),
+	(_gst_parse_yyget_in), (_gst_parse_yyget_out),
+	(_gst_parse_yyget_leng), (_gst_parse_yyget_text),
+	(_gst_parse_yyset_extra), (_gst_parse_yyset_lineno),
+	(_gst_parse_yyset_column), (_gst_parse_yyset_in),
+	(_gst_parse_yyset_out), (_gst_parse_yyget_debug),
+	(_gst_parse_yyset_debug), (_gst_parse_yyget_lval),
+	(_gst_parse_yyset_lval), (_gst_parse_yylex_init),
+	(yy_init_globals), (_gst_parse_yylex_destroy), (yy_flex_strncpy),
+	(yy_flex_strlen), (_gst_parse_yyalloc), (_gst_parse_yyrealloc),
+	(_gst_parse_yyfree):
+	If the installed flex version is too old use pre-generated parser
+	sources. These pre-generated parser sources are always updated when
+	the actual flex/bison sources change but require everybody who wants
+	to change something in the parser to have flex >= 2.5.31 installed.
+
 2007-04-18  Stefan Kost  <ensonic@users.sf.net>
 
 	* common/m4/gst-gettext.m4:

common

@@ -1 +1 @@
-Subproject commit 380281f0da9caa065cfe99a458b3538cc3f5d71a
+Subproject commit dae6fa1f592c9231820c2135b8b1b3c2b0875ef6

docs/gst/Makefile.am

@@ -73,6 +73,7 @@ IGNORE_HFILES= \
 	types.h \
 	glib-compat.h \
 	grammar.tab.h \
+	grammar.tab.pre.h \
 	gstmarshal.h \
 	gstaggregator.h \
 	gstbufferstore.h \

gst/gstparse.c

@@ -36,12 +36,6 @@
 #include "gstparse.h"
 #include "gstinfo.h"
 
-#ifndef HAVE_MT_SAVE_FLEX
-/* the need for the mutex will go away with flex 2.5.6 */
-static gboolean flex_busy = FALSE;
-static GStaticRecMutex flex_lock = G_STATIC_REC_MUTEX_INIT;
-#endif
-
 extern GstElement *_gst_parse_launch (const gchar *, GError **);
 
 /**
@@ -149,30 +143,9 @@ gst_parse_launch (const gchar * pipeline_description, GError ** error)
   GST_CAT_INFO (GST_CAT_PIPELINE, "parsing pipeline description %s",
       pipeline_description);
 
-#ifndef HAVE_MT_SAVE_FLEX
-  g_static_rec_mutex_lock (&flex_lock);
-  if (flex_busy)
-    goto recursive_call;
-  flex_busy = TRUE;
-#endif
-
   element = _gst_parse_launch (pipeline_description, error);
 
-#ifndef HAVE_MT_SAVE_FLEX
-  flex_busy = FALSE;
-  g_static_rec_mutex_unlock (&flex_lock);
-#endif
-
   return element;
 
   /* ERRORS */
-#ifndef HAVE_MT_SAVE_FLEX
-recursive_call:
-  {
-    GST_WARNING ("calls to gst_parse_launch() cannot be nested");
-    g_static_rec_mutex_unlock (&flex_lock);
-    g_warning ("calls to gst_parse_launch() cannot be nested");
-    return NULL;
-  }
-#endif
 }

gst/parse/Makefile.am

@@ -2,7 +2,13 @@
 noinst_LTLIBRARIES = libgstparse.la
 
 CLEANFILES = grammar.tab.h grammar.output
-EXTRA_DIST = grammar.y parse.l types.h
+EXTRA_DIST = \
+	grammar.y \
+	parse.l \
+	types.h \
+	grammar.tab.pre.c \
+	grammar.tab.pre.h \
+	lex._gst_parse_yy.pre.c
 
 # uncomment these lines to dist the generated sources
 #BUILT_SOURCES = grammar.tab.h grammar.tab.c lex._gst_parse_yy.c 
@@ -17,8 +23,10 @@ libgstparse_la_LIBADD = $(GST_ALL_LIBS)
 
 noinst_HEADERS = grammar.tab.h
 
-grammar.tab.c grammar.tab.h: grammar.y 
+all: grammar.tab.pre.c grammar.tab.pre.h lex._gst_parse_yy.pre.c
-	$(BISON_PATH) -d -v -p_gst_parse__yy $(srcdir)/grammar.y -o grammar.tab.c && \
+
+grammar.tab.pre.c grammar.tab.pre.h: grammar.y
+	$(BISON_PATH) -d -v -p_gst_parse_yy $(srcdir)/grammar.y -o grammar.tab.c && \
 	mv grammar.tab.c grammar.tab_tmp.c && \
 	echo '#ifdef HAVE_CONFIG_H' > grammar.tab_tmp2.c && \
 	echo '#include <config.h>' >> grammar.tab_tmp2.c && \
@@ -26,7 +34,37 @@ grammar.tab.c grammar.tab.h: grammar.y
 	cat grammar.tab_tmp.c >> grammar.tab_tmp2.c && \
 	rm grammar.tab_tmp.c && \
 	mv grammar.tab_tmp2.c grammar.tab.c
+	cp grammar.tab.c grammar.tab.pre.c
+	cp grammar.tab.h grammar.tab.pre.h
+
+lex._gst_parse_yy.pre.c: parse.l grammar.tab.pre.h
+	$(FLEX_PATH) -P_gst_parse_yy $^ && \
+	mv lex._gst_parse_yy.c lex._gst_parse_yy_tmp.c && \
+	echo '#ifdef HAVE_CONFIG_H' > lex._gst_parse_yy_tmp2.c && \
+	echo '#include <config.h>' >> lex._gst_parse_yy_tmp2.c && \
+	echo '#endif' >> lex._gst_parse_yy_tmp2.c && \
+	cat lex._gst_parse_yy_tmp.c >> lex._gst_parse_yy_tmp2.c && \
+	rm lex._gst_parse_yy_tmp.c && \
+	mv lex._gst_parse_yy_tmp2.c lex._gst_parse_yy.c
+	cp lex._gst_parse_yy.c lex._gst_parse_yy.pre.c
+
+if GENERATE_PARSER
+grammar.tab.c grammar.tab.h: grammar.y 
+	$(BISON_PATH) -d -v -p_gst_parse_yy $(srcdir)/grammar.y -o grammar.tab.c && \
+	mv grammar.tab.c grammar.tab_tmp.c && \
+	echo '#ifdef HAVE_CONFIG_H' > grammar.tab_tmp2.c && \
+	echo '#include <config.h>' >> grammar.tab_tmp2.c && \
+	echo '#endif' >> grammar.tab_tmp2.c && \
+	cat grammar.tab_tmp.c >> grammar.tab_tmp2.c && \
+	rm grammar.tab_tmp.c && \
+	mv grammar.tab_tmp2.c grammar.tab.c
+else
+grammar.tab.c grammar.tab.h: grammar.tab.pre.c grammar.tab.pre.h
+	cp $(srcdir)/grammar.tab.pre.h grammar.tab.h
+	cp $(srcdir)/grammar.tab.pre.c grammar.tab.c
+endif
  
+if GENERATE_PARSER
 lex._gst_parse_yy.c: parse.l grammar.tab.h
 	$(FLEX_PATH) -P_gst_parse_yy $^ && \
 	mv lex._gst_parse_yy.c lex._gst_parse_yy_tmp.c && \
@@ -36,6 +74,10 @@ lex._gst_parse_yy.c: parse.l grammar.tab.h
 	cat lex._gst_parse_yy_tmp.c >> lex._gst_parse_yy_tmp2.c && \
 	rm lex._gst_parse_yy_tmp.c && \
 	mv lex._gst_parse_yy_tmp2.c lex._gst_parse_yy.c
+else
+lex._gst_parse_yy.c: lex._gst_parse_yy.pre.c
+	cp $(srcdir)/lex._gst_parse_yy.pre.c lex._gst_parse_yy.c
+endif
 
 
 .NOTPARALLEL:

gst/parse/grammar.tab.pre.h

@@ -0,0 +1,83 @@
+/* A Bison parser, made by GNU Bison 2.3.  */
+
+/* Skeleton interface for Bison's Yacc-like parsers in C
+
+   Copyright (C) 1984, 1989, 1990, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+   Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+/* As a special exception, you may create a larger work that contains
+   part or all of the Bison parser skeleton and distribute that work
+   under terms of your choice, so long as that work isn't itself a
+   parser generator using the skeleton or a modified version thereof
+   as a parser skeleton.  Alternatively, if you modify or redistribute
+   the parser skeleton itself, you may (at your option) remove this
+   special exception, which will cause the skeleton and the resulting
+   Bison output files to be licensed under the GNU General Public
+   License without this special exception.
+
+   This special exception was added by the Free Software Foundation in
+   version 2.2 of Bison.  */
+
+/* Tokens.  */
+#ifndef YYTOKENTYPE
+# define YYTOKENTYPE
+   /* Put the tokens into the symbol table, so that GDB and other debuggers
+      know about them.  */
+   enum yytokentype {
+     PARSE_URL = 258,
+     IDENTIFIER = 259,
+     BINREF = 260,
+     PADREF = 261,
+     REF = 262,
+     ASSIGNMENT = 263,
+     LINK = 264
+   };
+#endif
+/* Tokens.  */
+#define PARSE_URL 258
+#define IDENTIFIER 259
+#define BINREF 260
+#define PADREF 261
+#define REF 262
+#define ASSIGNMENT 263
+#define LINK 264
+
+
+
+
+#if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
+typedef union YYSTYPE
+#line 468 "./grammar.y"
+{
+    gchar *s;
+    chain_t *c;
+    link_t *l;
+    GstElement *e;
+    GSList *p;
+    graph_t *g;
+}
+/* Line 1489 of yacc.c.  */
+#line 76 "grammar.tab.h"
+	YYSTYPE;
+# define yystype YYSTYPE /* obsolescent; will be withdrawn */
+# define YYSTYPE_IS_DECLARED 1
+# define YYSTYPE_IS_TRIVIAL 1
+#endif
+
+
+

gst/parse/grammar.y

@@ -24,7 +24,17 @@
  */
   
 #define YYERROR_VERBOSE 1
-#define YYPARSE_PARAM graph
+#define YYLEX_PARAM scanner
+
+typedef void* yyscan_t;
+
+int _gst_parse_yylex (void * yylval_param , yyscan_t yyscanner);
+int _gst_parse_yylex_init (yyscan_t scanner);
+int _gst_parse_yylex_destroy (yyscan_t scanner);
+struct yy_buffer_state * _gst_parse_yy_scan_string (char* , yyscan_t);
+void _gst_parse_yypush_buffer_state (void * new_buffer ,yyscan_t yyscanner );
+void _gst_parse_yypop_buffer_state (yyscan_t yyscanner );
+
 
 #ifdef __GST_PARSE_TRACE
 static guint __strings;
@@ -455,8 +465,7 @@ error:
 }
 
 
-static int yylex (void *lvalp);
+static int yyerror (void *scanner, graph_t *graph, const char *s);
-static int yyerror (const char *s);
 %}
 
 %union {
@@ -487,7 +496,9 @@ static int yyerror (const char *s);
 %right '.'
 %left '!' '='
 
-%pure_parser
+%parse-param { void *scanner }
+%parse-param { graph_t *graph }
+%pure-parser
 
 %start graph
 %%
@@ -712,23 +723,16 @@ graph:		/* NOP */		      { SET_ERROR (((graph_t *) graph)->error, GST_PARSE_ERRO
 
 %%
 
-extern FILE *_gst_parse_yyin;
-int _gst_parse_yylex (YYSTYPE *lvalp);
-
-static int yylex (void *lvalp) {
-    return _gst_parse_yylex ((YYSTYPE*) lvalp);
-}
 
 static int
-yyerror (const char *s)
+yyerror (void *scanner, graph_t *graph, const char *s)
 {
   /* FIXME: This should go into the GError somehow, but how? */
   GST_WARNING ("Error during parsing: %s", s);
   return -1;
 }
 
-struct yy_buffer_state * _gst_parse_yy_scan_string (char*);
+
-void _gst_parse_yy_delete_buffer (struct yy_buffer_state *);
 GstElement *
 _gst_parse_launch (const gchar *str, GError **error)
 {
@@ -737,8 +741,8 @@ _gst_parse_launch (const gchar *str, GError **error)
   GSList *walk;
   GstBin *bin = NULL;
   GstElement *ret;
-  struct yy_buffer_state *buf;
+  yyscan_t scanner;
-  
+
   g_return_val_if_fail (str != NULL, NULL);
 
   g.chain = NULL;
@@ -751,23 +755,24 @@ _gst_parse_launch (const gchar *str, GError **error)
 #endif /* __GST_PARSE_TRACE */
 
   dstr = g_strdup (str);
-  buf = _gst_parse_yy_scan_string (dstr);
+  _gst_parse_yylex_init (&scanner);
+  _gst_parse_yy_scan_string (dstr, scanner);
 
 #ifndef YYDEBUG
   yydebug = 1;
 #endif
 
-  if (yyparse (&g) != 0) {
+  if (yyparse (scanner, &g) != 0) {
     SET_ERROR (error, GST_PARSE_ERROR_SYNTAX,
         "Unrecoverable syntax error while parsing pipeline %s", str);
     
-    _gst_parse_yy_delete_buffer (buf);
+    _gst_parse_yylex_destroy (scanner);
     g_free (dstr);
   
     goto error1;
   }
+  _gst_parse_yylex_destroy (scanner);
   g_free (dstr);
-  _gst_parse_yy_delete_buffer (buf);
   
   GST_CAT_DEBUG (GST_CAT_PIPELINE, "got %u elements and %u links",
       g.chain ? g_slist_length (g.chain->elements) : 0,

gst/parse/parse.l

@@ -32,7 +32,6 @@ PRINT (const char *format, ...)
 }
 #endif
 
-#define YY_DECL int _gst_parse_yylex (YYSTYPE *lvalp)
 %}
 
 _operator [(){}.!,;=]
@@ -65,12 +64,14 @@ _link ("!"[[:space:]]*{_caps}([[:space:]]*(";"[[:space:]]*{_caps})*[[:space:]]*)
 %x value
 %option noyywrap
 %option nounput
+%option reentrant
+%option bison-bridge
 %%
 
 {_assignment} {
     /* "=" */
     PRINT ("ASSIGNMENT: %s", yytext);
-    lvalp->s = gst_parse_strdup (yytext);
+    yylval->s = gst_parse_strdup (yytext);
     BEGIN (INITIAL);
     return ASSIGNMENT;
 }
@@ -78,14 +79,14 @@ _link ("!"[[:space:]]*{_caps}([[:space:]]*(";"[[:space:]]*{_caps})*[[:space:]]*)
 {_padref} {
     yytext++;
     PRINT ("PADREF: %s", yytext);
-    lvalp->s = gst_parse_strdup (yytext);
+    yylval->s = gst_parse_strdup (yytext);
     BEGIN (INITIAL);
     return PADREF;
 }
 
 {_ref} {
     PRINT ("REF: %s", yytext);
-    lvalp->s = gst_parse_strdup (yytext);
+    yylval->s = gst_parse_strdup (yytext);
     BEGIN (INITIAL);
     return REF;
 }
@@ -95,14 +96,14 @@ _link ("!"[[:space:]]*{_caps}([[:space:]]*(";"[[:space:]]*{_caps})*[[:space:]]*)
     while (!g_ascii_isspace (*pos) && (*pos != '.')) pos++;
     *pos = '\0';
     PRINT ("BINREF: %s", yytext);
-    lvalp->s = gst_parse_strdup (yytext);
+    yylval->s = gst_parse_strdup (yytext);
     BEGIN (INITIAL);
     return BINREF;
 }
 
 {_identifier} {
     PRINT ("IDENTIFIER: %s", yytext);
-    lvalp->s = gst_parse_strdup (yytext);
+    yylval->s = gst_parse_strdup (yytext);
     BEGIN (INITIAL);
     return IDENTIFIER;
 }
@@ -113,22 +114,22 @@ _link ("!"[[:space:]]*{_caps}([[:space:]]*(";"[[:space:]]*{_caps})*[[:space:]]*)
     c++;
     if (*c) {
       while (g_ascii_isspace (*c)) c++;
-      c = lvalp->s = gst_parse_strdup (c);
+      c = yylval->s = gst_parse_strdup (c);
       while (*c) c++;
       if (*--c != '!')
 	g_assert_not_reached ();
       while (g_ascii_isspace (*--c));
       *++c = '\0';
     } else {
-      lvalp->s = NULL;
+      yylval->s = NULL;
     }
     BEGIN (INITIAL);
     return LINK;
 }
 {_url} {
   PRINT ("URL: %s", yytext);
-  lvalp->s = g_strdup (yytext);
+  yylval->s = g_strdup (yytext);
-  gst_parse_unescape (lvalp->s);
+  gst_parse_unescape (yylval->s);
   BEGIN (INITIAL);
   return PARSE_URL;
 }