gst/parse/grammar.y

   1 %{
   2 #include <glib.h>
   3 #include <stdio.h>
   4 #include "../gstparse.h"
   5 #include "types.h"
   6
   7 #define YYDEBUG 1
   8 #define YYERROR_VERBOSE 1
   9 #define YYPARSE_PARAM pgraph
  10
  11 static int yylex (void *lvalp);
  12 static int yyerror (const char *s);
  13 %}
  14
  15 %union {
  16     gchar *s;
  17     GValue *v;
  18     graph_t *g;
  19     connection_t *c;
  20     property_t *p;
  21     element_t *e;
  22 }
  23
  24 %token <s> IDENTIFIER
  25 %token <c> CONNECTION BCONNECTION
  26 %token <v> VALUE
  27
  28 %type <s> id
  29 %type <g> graph bin
  30 %type <e> element
  31 %type <p> property_value value
  32 %type <c> connection rconnection
  33
  34 %left '{' '}' '(' ')'
  35 %left '!' '='
  36 %left ','
  37 %left '.'
  38
  39 %pure_parser
  40
  41 %start graph
  42 %%
  43
  44 id:     IDENTIFIER
  45         ;
  46
  47 value:          VALUE                { $$ = g_new0 (property_t, 1); $$->value = $1; }
  48         ;
  49
  50 property_value: id '=' value         { $$ = $3; $$->name = $1; }
  51         ;
  52
  53 element:        id                   { static int i = 0; $$ = g_new0 (element_t, 1);
  54                                        $$->type = $1; $$->index = ++i; }
  55         ;
  56
  57 graph:          /* empty */          { $$ = g_new0 (graph_t, 1); *((graph_t**) pgraph) = $$; }
  58         |       graph element        { GList *l;
  59                                        $$ = $1; l = $$->connections_pending;
  60                                        $$->elements = g_list_append ($$->elements, $2);
  61                                        $$->current = $2;
  62                                        if (!$$->first)
  63                                            $$->first = $$->current;
  64                                        while (l) {
  65                                            ((connection_t*) l->data)->sink_index = $$->current->index;
  66                                            l = g_list_next (l);
  67                                        }
  68                                        if ($$->connections_pending) {
  69                                            g_list_free ($$->connections_pending);
  70                                            $$->connections_pending = NULL;
  71                                        }
  72                                      }
  73         |       graph bin            { GList *l; $$ = $1; l = $$->connections_pending;
  74                                        *((graph_t**) pgraph) = $$;
  75                                        $$->bins = g_list_append ($$->bins, $2);
  76                                        $2->parent = $$;
  77                                        $$->current = $2->first;
  78                                        if (!$$->first)
  79                                            $$->first = $$->current;
  80                                        while (l) {
  81                                            ((connection_t*) l->data)->sink_index = $$->current->index;
  82                                            l = g_list_next (l);
  83                                        }
  84                                        if ($$->connections_pending) {
  85                                            g_list_free ($$->connections_pending);
  86                                            $$->connections_pending = NULL;
  87                                        }
  88                                        $$->current = $2->current;
  89                                      }
  90         |       graph connection     { $$ = $1;
  91                                        $$->connections = g_list_append ($$->connections, $2);
  92                                        $2->src_index = $$->current->index;
  93                                        if (!$2->sink_name)
  94                                            $$->connections_pending = g_list_append ($$->connections_pending, $2);
  95                                      }
  96         |       graph property_value { $$ = $1;
  97                                        $$->current->property_values = g_list_append ($$->current->property_values,
  98                                                                                      $2);
  99                                      }
 100         ;
 101
 102 bin:            '{' graph '}'        { $$ = $2; $$->current_bin_type = "thread"; }
 103         |       id '.' '(' graph ')' { $$ = $4; $$->current_bin_type = $1; }
 104         ;
 105
 106 connection:     CONNECTION
 107         |       rconnection
 108         ;
 109
 110 rconnection:   '!'                   { $$ = g_new0 (connection_t, 1); }
 111         |       BCONNECTION          { $$ = $1; }
 112         |       id ',' rconnection ',' id
 113                                      { $$ = $3;
 114                                        $$->src_pads = g_list_prepend ($$->src_pads, $1);
 115                                        $$->sink_pads = g_list_append ($$->sink_pads, $5);
 116                                      }
 117         ;
 118
 119 %%
 120
 121 extern FILE *yyin;
 122 int _gst_parse_yylex (YYSTYPE *lvalp);
 123
 124 static int yylex (void *lvalp) {
 125     return _gst_parse_yylex ((YYSTYPE*) lvalp);
 126 }
 127
 128 static int
 129 yyerror (const char *s)
 130 {
 131   printf ("error: %s\n", s);
 132   return -1;
 133 }
 134
 135 int yy_scan_string (char*);
 136
 137 graph_t * _gst_parse_launch (const gchar *str, GError **error)
 138 {
 139     graph_t *g = NULL;
 140     gchar *dstr;
 141
 142     g_return_val_if_fail (str != NULL, NULL);
 143
 144     dstr = g_strdup (str);
 145     yy_scan_string (dstr);
 146
 147 #ifdef DEBUG
 148     yydebug = 1;
 149 #endif
 150
 151     if (yyparse (&g) != 0) {
 152         g_set_error (error,
 153                      GST_PARSE_ERROR,
 154                      GST_PARSE_ERROR_SYNTAX,
 155                      "Invalid syntax");
 156         g_free (dstr);
 157         return NULL;
 158     }
 159
 160     g_assert (g != NULL);
 161
 162     g_free (dstr);
 163
 164     return g;
 165 }