gstreamer/gst/parse/grammar.y

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%{
#include <glib.h>
#include <stdio.h>
#include <string.h>
#include "../gstparse.h"
#include "types.h"
#define YYDEBUG 1
#define YYERROR_VERBOSE 1
#define YYPARSE_PARAM pgraph
static int yylex (void *lvalp);
static int yyerror (const char *s);
%}
%union {
gchar *s;
GValue *v;
graph_t *g;
link_t *c;
property_t *p;
element_t *e;
}
%token <s> IDENTIFIER
%token <c> LINK BLINK FLINK
%token <v> VALUE
%type <s> id
%type <g> graph bin
%type <e> element
%type <p> property_value value
%type <c> link rlink
%left '{' '}' '(' ')'
%left '!' '='
%left ','
%left '.'
%pure_parser
%start graph
%%
id: IDENTIFIER
;
value: VALUE { $$ = g_new0 (property_t, 1); $$->value = $1; }
;
property_value: id '=' value { $$ = $3; $$->name = $1; }
;
element: id { static int i = 0; $$ = g_new0 (element_t, 1);
$$->type = $1; $$->index = ++i; }
;
graph: /* empty */ { $$ = g_new0 (graph_t, 1); *((graph_t**) pgraph) = $$; }
| graph element { GList *l;
$$ = $1; l = $$->links_pending;
$$->elements = g_list_append ($$->elements, $2);
$$->current = $2;
if (!$$->first)
$$->first = $$->current;
while (l) {
((link_t*) l->data)->sink_index = $$->current->index;
l = g_list_next (l);
}
if ($$->links_pending) {
g_list_free ($$->links_pending);
$$->links_pending = NULL;
}
}
| graph bin { GList *l; $$ = $1; l = $$->links_pending;
*((graph_t**) pgraph) = $$;
$$->bins = g_list_append ($$->bins, $2);
$2->parent = $$;
$$->current = $2->first;
if (!$$->first)
$$->first = $$->current;
while (l) {
((link_t*) l->data)->sink_index = $$->current->index;
l = g_list_next (l);
}
if ($$->links_pending) {
g_list_free ($$->links_pending);
$$->links_pending = NULL;
}
$$->current = $2->current;
}
| graph link { $$ = $1;
$$->links = g_list_append ($$->links, $2);
if ($$->current)
$2->src_index = $$->current->index;
if (!$2->sink_name)
$$->links_pending = g_list_append ($$->links_pending, $2);
}
| graph property_value { $$ = $1;
if (!$$->current) {
fprintf (stderr, "error: property value assignments must be preceded by an element definition\n");
YYABORT;
}
$$->current->property_values = g_list_append ($$->current->property_values,
$2);
}
;
bin: '{' graph '}' { $$ = $2; $$->current_bin_type = "thread"; }
| id '.' '(' graph ')' { $$ = $4; $$->current_bin_type = $1; }
;
link: LINK
| rlink
;
rlink: '!' { $$ = g_new0 (link_t, 1); }
| BLINK { $$ = $1; }
| FLINK { $$ = $1; }
| id ',' rlink ',' id
{ $$ = $3;
$$->src_pads = g_list_prepend ($$->src_pads, $1);
$$->sink_pads = g_list_append ($$->sink_pads, $5);
}
;
%%
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)
{
fprintf (stderr, "error: %s\n", s);
return -1;
}
int _gst_parse_yy_scan_string (char*);
graph_t * _gst_parse_launch (const gchar *str, GError **error)
{
graph_t *g = NULL;
gchar *dstr;
g_return_val_if_fail (str != NULL, NULL);
dstr = g_strdup (str);
_gst_parse_yy_scan_string (dstr);
#ifdef DEBUG
_gst_parse_yydebug = 1;
#endif
if (yyparse (&g) != 0) {
g_set_error (error,
GST_PARSE_ERROR,
GST_PARSE_ERROR_SYNTAX,
"Invalid syntax");
g_free (dstr);
return NULL;
}
g_assert (g != NULL);
g_free (dstr);
/* if the toplevel only contains one bin, make that bin top-level */
if (g->elements == NULL && g->bins && g->bins->next == NULL) {
g = (graph_t*)g->bins->data;
g_free (g->parent);
g->parent = NULL;
}
return g;
}