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gstreamer/gst/parse/grammar.y
Fabian Kirsch ffe072f694 parse: Some minor fixes 
Fix destructor segfaulting
Expect 0 grammar-ambiguities
Fix order of bin-properties assignment

https://bugzilla.gnome.org/show_bug.cgi?id=710034
2014-01-16 15:38:51 +01:00

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%{
#include "../gst_private.h"
#include <glib-object.h>
#include <glib.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "../gst-i18n-lib.h"
#include "../gstconfig.h"
#include "../gstparse.h"
#include "../gstinfo.h"
#include "../gsterror.h"
#include "../gststructure.h"
#include "../gsturi.h"
#include "../gstutils.h"
#include "../gstvalue.h"
#include "../gstchildproxy.h"
#include "types.h"
/* All error messages in this file are user-visible and need to be translated.
* Don't start the message with a capital, and don't end them with a period,
* as they will be presented inside a sentence/error.
*/
#define YYERROR_VERBOSE 1
#define YYENABLE_NLS 0
#ifndef YYLTYPE_IS_TRIVIAL
#define YYLTYPE_IS_TRIVIAL 0
#endif
/*******************************************************************************************
*** Tracing memory leaks
*******************************************************************************************/
#ifdef __GST_PARSE_TRACE
static guint __strings;
static guint __links;
static guint __chains;
gchar *
__gst_parse_strdup (gchar *org)
{
gchar *ret;
__strings++;
ret = g_strdup (org);
/* g_print ("ALLOCATED STR (%3u): %p %s\n", __strings, ret, ret); */
return ret;
}
void
__gst_parse_strfree (gchar *str)
{
if (str) {
/* g_print ("FREEING STR (%3u): %p %s\n", __strings - 1, str, str); */
g_free (str);
g_return_if_fail (__strings > 0);
__strings--;
}
}
link_t *__gst_parse_link_new (void)
{
link_t *ret;
__links++;
ret = g_slice_new0 (link_t);
/* g_print ("ALLOCATED LINK (%3u): %p\n", __links, ret); */
return ret;
}
void
__gst_parse_link_free (link_t *data)
{
if (data) {
/* g_print ("FREEING LINK (%3u): %p\n", __links - 1, data); */
g_slice_free (link_t, data);
g_return_if_fail (__links > 0);
__links--;
}
}
chain_t *
__gst_parse_chain_new (void)
{
chain_t *ret;
__chains++;
ret = g_slice_new0 (chain_t);
/* g_print ("@%p: ALLOCATED CHAIN (%3u):\n", ret, __chains); */
return ret;
}
void
__gst_parse_chain_free (chain_t *data)
{
/* g_print ("@%p: FREEING CHAIN (%3u):\n", data, __chains - 1); */
g_slice_free (chain_t, data);
g_return_if_fail (__chains > 0);
__chains--;
}
#endif /* __GST_PARSE_TRACE */
/*******************************************************************************************
*** define SET_ERROR macro/function
*******************************************************************************************/
#ifdef G_HAVE_ISO_VARARGS
# define SET_ERROR(error, type, ...) \
G_STMT_START { \
GST_CAT_ERROR (GST_CAT_PIPELINE, __VA_ARGS__); \
if ((error) && !*(error)) { \
g_set_error ((error), GST_PARSE_ERROR, (type), __VA_ARGS__); \
} \
} G_STMT_END
#elif defined(G_HAVE_GNUC_VARARGS)
# define SET_ERROR(error, type, args...) \
G_STMT_START { \
GST_CAT_ERROR (GST_CAT_PIPELINE, args ); \
if ((error) && !*(error)) { \
g_set_error ((error), GST_PARSE_ERROR, (type), args ); \
} \
} G_STMT_END
#else
static inline void
SET_ERROR (GError **error, gint type, const char *format, ...)
{
if (error) {
if (*error) {
g_warning ("error while parsing");
} else {
va_list varargs;
char *string;
va_start (varargs, format);
string = g_strdup_vprintf (format, varargs);
va_end (varargs);
g_set_error (error, GST_PARSE_ERROR, type, string);
g_free (string);
}
}
}
#endif /* G_HAVE_ISO_VARARGS */
/*** define YYPRINTF macro/function if we're debugging */
/* bison 1.35 calls this macro with side effects, we need to make sure the
side effects work - crappy bison */
#ifndef GST_DISABLE_GST_DEBUG
# define YYDEBUG 1
# ifdef G_HAVE_ISO_VARARGS
/* # define YYFPRINTF(a, ...) GST_CAT_DEBUG (GST_CAT_PIPELINE, __VA_ARGS__) */
# define YYFPRINTF(a, ...) \
G_STMT_START { \
GST_CAT_LOG (GST_CAT_PIPELINE, __VA_ARGS__); \
} G_STMT_END
# elif defined(G_HAVE_GNUC_VARARGS)
# define YYFPRINTF(a, args...) \
G_STMT_START { \
GST_CAT_LOG (GST_CAT_PIPELINE, args); \
} G_STMT_END
# else
static inline void
YYPRINTF(const char *format, ...)
{
va_list varargs;
gchar *temp;
va_start (varargs, format);
temp = g_strdup_vprintf (format, varargs);
GST_CAT_LOG (GST_CAT_PIPELINE, "%s", temp);
g_free (temp);
va_end (varargs);
}
# endif /* G_HAVE_ISO_VARARGS */
#endif /* GST_DISABLE_GST_DEBUG */
/*
* include headers generated by bison & flex, after defining (or not defining) YYDEBUG
*/
#include "grammar.tab.h"
#include "parse_lex.h"
/*******************************************************************************************
*** report missing elements/bins/..
*******************************************************************************************/
static void add_missing_element(graph_t *graph,gchar *name){
if ((graph)->ctx){
(graph)->ctx->missing_elements = g_list_append ((graph)->ctx->missing_elements, g_strdup (name));
}
}
/*******************************************************************************************
*** helpers for pipeline-setup
*******************************************************************************************/
#define TRY_SETUP_LINK(l) G_STMT_START { \
if( (!(l)->src.element) && (!(l)->src.name) ){ \
SET_ERROR (graph->error, GST_PARSE_ERROR_LINK, _("link has no source [sink=%s@%p]"), \
(l)->sink.name ? (l)->sink.name : _(""), \
(l)->sink.element); \
gst_parse_free_link (l); \
}else if( (!(l)->sink.element) && (!(l)->sink.name) ){ \
SET_ERROR (graph->error, GST_PARSE_ERROR_LINK, _("link has no sink [source=%s@%p]"), \
(l)->src.name ? (l)->src.name :_(""), \
(l)->src.element); \
gst_parse_free_link (l); \
}else{ \
graph->links = g_slist_append (graph->links, l ); \
} \
} G_STMT_END
typedef struct {
gchar *src_pad;
gchar *sink_pad;
GstElement *sink;
GstCaps *caps;
gulong signal_id;
} DelayedLink;
typedef struct {
gchar *name;
gchar *value_str;
gulong signal_id;
} DelayedSet;
static int gst_resolve_reference(reference_t *rr, GstElement *pipeline){
GstBin *bin;
if(rr->element) return 0; /* already resolved! */
if(!rr->name) return -2; /* no chance! */
if (GST_IS_BIN (pipeline)){
bin = GST_BIN (pipeline);
rr->element = gst_bin_get_by_name_recurse_up (bin, rr->name);
} else {
rr->element = strcmp (GST_ELEMENT_NAME (pipeline), rr->name) == 0 ?
gst_object_ref(pipeline) : NULL;
}
if(rr->element) return 0; /* resolved */
else return -1; /* not found */
}
static void gst_parse_free_delayed_set (DelayedSet *set)
{
g_free(set->name);
g_free(set->value_str);
g_slice_free(DelayedSet, set);
}
static void gst_parse_new_child(GstChildProxy *child_proxy, GObject *object,
const gchar * name, gpointer data);
static void gst_parse_add_delayed_set (GstElement *element, gchar *name, gchar *value_str)
{
DelayedSet *data = g_slice_new0 (DelayedSet);
GST_CAT_LOG_OBJECT (GST_CAT_PIPELINE, element, "delaying property set %s to %s",
name, value_str);
data->name = g_strdup(name);
data->value_str = g_strdup(value_str);
data->signal_id = g_signal_connect_data(element, "child-added",
G_CALLBACK (gst_parse_new_child), data, (GClosureNotify)
gst_parse_free_delayed_set, (GConnectFlags) 0);
/* FIXME: we would need to listen on all intermediate bins too */
if (GST_IS_BIN (element)) {
gchar **names, **current;
GstElement *parent, *child;
current = names = g_strsplit (name, "::", -1);
parent = gst_bin_get_by_name (GST_BIN_CAST (element), current[0]);
current++;
while (parent && current[0]) {
child = gst_bin_get_by_name (GST_BIN (parent), current[0]);
if (!child && current[1]) {
char *sub_name = g_strjoinv ("::", &current[0]);
gst_parse_add_delayed_set(parent, sub_name, value_str);
g_free (sub_name);
}
parent = child;
current++;
}
g_strfreev (names);
}
}
static void gst_parse_new_child(GstChildProxy *child_proxy, GObject *object,
const gchar * name, gpointer data)
{
DelayedSet *set = (DelayedSet *) data;
GParamSpec *pspec;
GValue v = { 0, };
GObject *target = NULL;
GType value_type;
GST_CAT_LOG_OBJECT (GST_CAT_PIPELINE, child_proxy, "new child %s, checking property %s",
name, set->name);
if (gst_child_proxy_lookup (child_proxy, set->name, &target, &pspec)) {
gboolean got_value = FALSE;
value_type = pspec->value_type;
GST_CAT_LOG_OBJECT (GST_CAT_PIPELINE, child_proxy, "parsing delayed property %s as a %s from %s",
pspec->name, g_type_name (value_type), set->value_str);
g_value_init (&v, value_type);
if (gst_value_deserialize (&v, set->value_str))
got_value = TRUE;
else if (g_type_is_a (value_type, GST_TYPE_ELEMENT)) {
GstElement *bin;
bin = gst_parse_bin_from_description_full (set->value_str, TRUE, NULL,
GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS, NULL);
if (bin) {
g_value_set_object (&v, bin);
got_value = TRUE;
}
}
g_signal_handler_disconnect (child_proxy, set->signal_id);
if (!got_value)
goto error;
g_object_set_property (target, pspec->name, &v);
} else {
const gchar *obj_name = GST_OBJECT_NAME(object);
gint len = strlen (obj_name);
/* do a delayed set */
if ((strlen (set->name) > (len + 2)) && !strncmp (set->name, obj_name, len) && !strncmp (&set->name[len], "::", 2)) {
gst_parse_add_delayed_set (GST_ELEMENT(child_proxy), set->name, set->value_str);
}
}
out:
if (G_IS_VALUE (&v))
g_value_unset (&v);
if (target)
g_object_unref (target);
return;
error:
GST_CAT_ERROR (GST_CAT_PIPELINE, "could not set property \"%s\" in %"
GST_PTR_FORMAT, pspec->name, target);
goto out;
}
static void gst_parse_element_set (gchar *value, GstElement *element, graph_t *graph)
{
GParamSpec *pspec = NULL;
gchar *pos = value;
GValue v = { 0, };
GObject *target = NULL;
GType value_type;
/* do nothing if assignment is for missing element */
if (element == NULL)
goto out;
/* parse the string, so the property name is null-terminated and pos points
to the beginning of the value */
while (!g_ascii_isspace (*pos) && (*pos != '=')) pos++;
if (*pos == '=') {
*pos = '\0';
} else {
*pos = '\0';
pos++;
while (g_ascii_isspace (*pos)) pos++;
}
pos++;
while (g_ascii_isspace (*pos)) pos++;
if (*pos == '"') {
pos++;
pos[strlen (pos) - 1] = '\0';
}
gst_parse_unescape (pos);
if (GST_IS_CHILD_PROXY (element)) {
if (!gst_child_proxy_lookup (GST_CHILD_PROXY (element), value, &target, &pspec)) {
/* do a delayed set */
gst_parse_add_delayed_set (element, value, pos);
}
} else {
pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (element), value);
if (pspec != NULL) {
target = g_object_ref (element);
GST_CAT_LOG_OBJECT (GST_CAT_PIPELINE, target, "found %s property", value);
} else {
SET_ERROR (graph->error, GST_PARSE_ERROR_NO_SUCH_PROPERTY, \
_("no property \"%s\" in element \"%s\""), value, \
GST_ELEMENT_NAME (element));
}
}
if (pspec != NULL && target != NULL) {
gboolean got_value = FALSE;
value_type = pspec->value_type;
GST_CAT_LOG_OBJECT (GST_CAT_PIPELINE, element, "parsing property %s as a %s",
pspec->name, g_type_name (value_type));
g_value_init (&v, value_type);
if (gst_value_deserialize (&v, pos))
got_value = TRUE;
else if (g_type_is_a (value_type, GST_TYPE_ELEMENT)) {
GstElement *bin;
bin = gst_parse_bin_from_description_full (pos, TRUE, NULL,
GST_PARSE_FLAG_NO_SINGLE_ELEMENT_BINS, NULL);
if (bin) {
g_value_set_object (&v, bin);
got_value = TRUE;
}
}
if (!got_value)
goto error;
g_object_set_property (target, pspec->name, &v);
}
out:
gst_parse_strfree (value);
if (G_IS_VALUE (&v))
g_value_unset (&v);
if (target)
g_object_unref (target);
return;
error:
SET_ERROR (graph->error, GST_PARSE_ERROR_COULD_NOT_SET_PROPERTY,
_("could not set property \"%s\" in element \"%s\" to \"%s\""),
value, GST_ELEMENT_NAME (element), pos);
goto out;
}
static void gst_parse_free_reference (reference_t *rr)
{
if(rr->element) gst_object_unref(rr->element);
gst_parse_strfree (rr->name);
g_slist_foreach (rr->pads, (GFunc) gst_parse_strfree, NULL);
g_slist_free (rr->pads);
}
static void gst_parse_free_link (link_t *link)
{
gst_parse_free_reference (&(link->src));
gst_parse_free_reference (&(link->sink));
if (link->caps) gst_caps_unref (link->caps);
gst_parse_link_free (link);
}
static void gst_parse_free_chain (chain_t *ch)
{
GSList *walk;
gst_parse_free_reference (&(ch->first));
gst_parse_free_reference (&(ch->last));
for(walk=ch->elements;walk;walk=walk->next)
gst_object_unref (walk->data);
g_slist_free (ch->elements);
gst_parse_chain_free (ch);
}
static void gst_parse_free_delayed_link (DelayedLink *link)
{
g_free (link->src_pad);
g_free (link->sink_pad);
if (link->caps) gst_caps_unref (link->caps);
g_slice_free (DelayedLink, link);
}
static void gst_parse_found_pad (GstElement *src, GstPad *pad, gpointer data)
{
DelayedLink *link = data;
GST_CAT_INFO (GST_CAT_PIPELINE, "trying delayed linking %s:%s to %s:%s",
GST_STR_NULL (GST_ELEMENT_NAME (src)), GST_STR_NULL (link->src_pad),
GST_STR_NULL (GST_ELEMENT_NAME (link->sink)), GST_STR_NULL (link->sink_pad));
if (gst_element_link_pads_filtered (src, link->src_pad, link->sink,
link->sink_pad, link->caps)) {
/* do this here, we don't want to get any problems later on when
* unlocking states */
GST_CAT_DEBUG (GST_CAT_PIPELINE, "delayed linking %s:%s to %s:%s worked",
GST_STR_NULL (GST_ELEMENT_NAME (src)), GST_STR_NULL (link->src_pad),
GST_STR_NULL (GST_ELEMENT_NAME (link->sink)), GST_STR_NULL (link->sink_pad));
g_signal_handler_disconnect (src, link->signal_id);
}
}
/* both padnames and the caps may be NULL */
static gboolean
gst_parse_perform_delayed_link (GstElement *src, const gchar *src_pad,
GstElement *sink, const gchar *sink_pad,
GstCaps *caps)
{
GList *templs = gst_element_class_get_pad_template_list (
GST_ELEMENT_GET_CLASS (src));
for (; templs; templs = templs->next) {
GstPadTemplate *templ = (GstPadTemplate *) templs->data;
if ((GST_PAD_TEMPLATE_DIRECTION (templ) == GST_PAD_SRC) &&
(GST_PAD_TEMPLATE_PRESENCE(templ) == GST_PAD_SOMETIMES))
{
DelayedLink *data = g_slice_new (DelayedLink);
/* TODO: maybe we should check if src_pad matches this template's names */
GST_CAT_DEBUG (GST_CAT_PIPELINE, "trying delayed link %s:%s to %s:%s",
GST_STR_NULL (GST_ELEMENT_NAME (src)), GST_STR_NULL (src_pad),
GST_STR_NULL (GST_ELEMENT_NAME (sink)), GST_STR_NULL (sink_pad));
data->src_pad = g_strdup (src_pad);
data->sink = sink;
data->sink_pad = g_strdup (sink_pad);
if (caps) {
data->caps = gst_caps_copy (caps);
} else {
data->caps = NULL;
}
data->signal_id = g_signal_connect_data (src, "pad-added",
G_CALLBACK (gst_parse_found_pad), data,
(GClosureNotify) gst_parse_free_delayed_link, (GConnectFlags) 0);
return TRUE;
}
}
return FALSE;
}
/*
* performs a link and frees the struct. src and sink elements must be given
* return values 0 - link performed
* 1 - link delayed
* <0 - error
*/
static gint
gst_parse_perform_link (link_t *link, graph_t *graph)
{
GstElement *src = link->src.element;
GstElement *sink = link->sink.element;
GSList *srcs = link->src.pads;
GSList *sinks = link->sink.pads;
g_assert (GST_IS_ELEMENT (src));
g_assert (GST_IS_ELEMENT (sink));
GST_CAT_INFO (GST_CAT_PIPELINE,
"linking %s:%s to %s:%s (%u/%u) with caps \"%" GST_PTR_FORMAT "\"",
GST_ELEMENT_NAME (src), link->src.name ? link->src.name : "(any)",
GST_ELEMENT_NAME (sink), link->sink.name ? link->sink.name : "(any)",
g_slist_length (srcs), g_slist_length (sinks), link->caps);
if (!srcs || !sinks) {
if (gst_element_link_pads_filtered (src,
srcs ? (const gchar *) srcs->data : NULL, sink,
sinks ? (const gchar *) sinks->data : NULL, link->caps)) {
goto success;
} else {
if (gst_parse_perform_delayed_link (src,
srcs ? (const gchar *) srcs->data : NULL,
sink, sinks ? (const gchar *) sinks->data : NULL, link->caps)) {
goto success;
} else {
goto error;
}
}
}
if (g_slist_length (link->src.pads) != g_slist_length (link->sink.pads)) {
goto error;
}
while (srcs && sinks) {
const gchar *src_pad = (const gchar *) srcs->data;
const gchar *sink_pad = (const gchar *) sinks->data;
srcs = g_slist_next (srcs);
sinks = g_slist_next (sinks);
if (gst_element_link_pads_filtered (src, src_pad, sink, sink_pad,
link->caps)) {
continue;
} else {
if (gst_parse_perform_delayed_link (src, src_pad,
sink, sink_pad,
link->caps)) {
continue;
} else {
goto error;
}
}
}
success:
gst_parse_free_link (link);
return 0;
error:
SET_ERROR (graph->error, GST_PARSE_ERROR_LINK,
_("could not link %s to %s"), GST_ELEMENT_NAME (src),
GST_ELEMENT_NAME (sink));
gst_parse_free_link (link);
return -1;
}
static int yyerror (void *scanner, graph_t *graph, const char *s);
%}
%union {
gchar *ss;
chain_t *cc;
link_t *ll;
reference_t rr;
GstElement *ee;
GSList *pp;
graph_t *gg;
}
/* No grammar ambiguities expected, FAIL otherwise */
%expect 0
%token <ss> PARSE_URL
%token <ss> IDENTIFIER
%left <ss> REF PADREF BINREF
%token <ss> ASSIGNMENT
%token <ss> LINK
%type <ss> binopener
%type <gg> graph
%type <cc> chain bin chainlist openchain elementary
%type <rr> reference
%type <ll> link
%type <ee> element
%type <pp> morepads pads assignments
%destructor { gst_parse_strfree ($$); } <ss>
%destructor { if($$)
gst_parse_free_chain($$); } <cc>
%destructor { gst_parse_free_link ($$); } <ll>
%destructor { gst_parse_free_reference(&($$));} <rr>
%destructor { gst_object_unref ($$); } <ee>
%destructor { GSList *walk;
for(walk=$$;walk;walk=walk->next)
gst_parse_strfree (walk->data);
g_slist_free ($$); } <pp>
%left '(' ')'
%left ','
%right '.'
%left '!' '='
%lex-param { void *scanner }
%parse-param { void *scanner }
%parse-param { graph_t *graph }
%pure-parser
%start graph
%%
/*************************************************************
* Grammar explanation:
* _element_s are specified by an identifier of their type.
* a name can be give in the optional property-assignments
* coffeeelement
* fakesrc name=john
* identity silence=false name=frodo
* (cont'd)
**************************************************************/
element: IDENTIFIER { $$ = gst_element_factory_make ($1, NULL);
if ($$ == NULL) {
add_missing_element(graph, $1);
SET_ERROR (graph->error, GST_PARSE_ERROR_NO_SUCH_ELEMENT, _("no element \"%s\""), $1);
}
gst_parse_strfree ($1);
}
| element ASSIGNMENT { gst_parse_element_set ($2, $1, graph);
$$ = $1;
}
;
/*************************************************************
* Grammar explanation: (cont'd)
* a graph has (pure) _element_s, _bin_s and _link_s.
* since bins are special elements, bins and elements can
* be generalized as _elementary_.
* The construction of _bin_s will be discussed later.
* (cont'd)
*
**************************************************************/
elementary:
element { $$ = gst_parse_chain_new ();
/* g_print ("@%p: CHAINing elementary\n", $$); */
$$->first.element = $1? gst_object_ref($1) : NULL;
$$->last.element = $1? gst_object_ref($1) : NULL;
$$->first.name = $$->last.name = NULL;
$$->first.pads = $$->last.pads = NULL;
$$->elements = $1 ? g_slist_prepend (NULL, $1) : NULL;
}
| bin { $$=$1; }
;
/*************************************************************
* Grammar explanation: (cont'd)
* a _chain_ is a list of _elementary_s that have _link_s inbetween
* which are represented through infix-notation.
*
* fakesrc ! sometransformation ! fakesink
*
* every _link_ can be augmented with _pads_.
*
* coffeesrc .sound ! speakersink
* multisrc .movie,ads ! .projector,smallscreen multisink
*
* and every _link_ can be setup to filter media-types
* mediasrc ! audio/x-raw, signed=TRUE ! stereosink
*
* User HINT:
* if the lexer does not recognize your media-type it
* will make it an element name. that results in errors
* like
* NO SUCH ELEMENT: no element audio7x-raw
* '7' vs. '/' in https://en.wikipedia.org/wiki/QWERTZ
*
* Parsing HINT:
* in the parser we need to differ between chains that can
* be extended by more elementaries (_openchain_) and others
* that are syntactically closed (handled later in this file).
* (e.g. fakesrc ! sinkreferencename.padname)
**************************************************************/
chain: openchain { $$=$1;
if($$->last.name){
SET_ERROR (graph->error, GST_PARSE_ERROR_SYNTAX,
_("unexpected reference \"%s\" - ignoring"), $$->last.name);
gst_parse_strfree($$->last.name);
$$->last.name=NULL;
}
if($$->last.pads){
SET_ERROR (graph->error, GST_PARSE_ERROR_SYNTAX,
_("unexpected pad-reference \"%s\" - ignoring"), (gchar*)$$->last.pads->data);
g_slist_foreach ($$->last.pads, (GFunc) gst_parse_strfree, NULL);
g_slist_free ($$->last.pads);
$$->last.pads=NULL;
}
}
;
openchain:
elementary pads { $$=$1;
$$->last.pads = g_slist_concat ($$->last.pads, $2);
/* g_print ("@%p@%p: FKI elementary pads\n", $1, $$->last.pads); */
}
| openchain link pads elementary pads
{
$2->src = $1->last;
$2->sink = $4->first;
$2->sink.pads = g_slist_concat ($3, $2->sink.pads);
TRY_SETUP_LINK($2);
$4->first = $1->first;
$4->elements = g_slist_concat ($1->elements, $4->elements);
gst_parse_chain_free($1);
$$ = $4;
$$->last.pads = g_slist_concat ($$->last.pads, $5);
}
;
link: LINK { $$ = gst_parse_link_new ();
$$->src.element = NULL;
$$->sink.element = NULL;
$$->src.name = NULL;
$$->sink.name = NULL;
$$->src.pads = NULL;
$$->sink.pads = NULL;
$$->caps = NULL;
if ($1) {
$$->caps = gst_caps_from_string ($1);
if ($$->caps == NULL)
SET_ERROR (graph->error, GST_PARSE_ERROR_LINK, _("could not parse caps \"%s\""), $1);
gst_parse_strfree ($1);
}
}
;
pads: /* NOP */ { $$ = NULL; }
| PADREF morepads { $$ = $2;
$$ = g_slist_prepend ($$, $1);
}
;
morepads: /* NOP */ { $$ = NULL; }
| ',' IDENTIFIER morepads { $$ = g_slist_prepend ($3, $2); }
;
/*************************************************************
* Grammar explanation: (cont'd)
* the first and last elements of a _chain_ can be give
* as URL. This creates special elements that fit the URL.
*
* fakesrc ! http://fake-sink.org
* http://somesource.org ! fakesink
**************************************************************/
chain: openchain link PARSE_URL { GstElement *element =
gst_element_make_from_uri (GST_URI_SINK, $3, NULL, NULL);
/* FIXME: get and parse error properly */
if (!element) {
SET_ERROR (graph->error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
_("no sink element for URI \"%s\""), $3);
}
$$ = $1;
$2->sink.element = element?gst_object_ref(element):NULL;
$2->src = $1->last;
TRY_SETUP_LINK($2);
$$->last.element = NULL;
$$->last.name = NULL;
$$->last.pads = NULL;
if(element) $$->elements = g_slist_append ($$->elements, element);
g_free ($3);
}
;
openchain:
PARSE_URL { GstElement *element =
gst_element_make_from_uri (GST_URI_SRC, $1, NULL, NULL);
/* FIXME: get and parse error properly */
if (!element) {
SET_ERROR (graph->error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
_("no source element for URI \"%s\""), $1);
}
$$ = gst_parse_chain_new ();
/* g_print ("@%p: CHAINing srcURL\n", $$); */
$$->first.element = NULL;
$$->first.name = NULL;
$$->first.pads = NULL;
$$->last.element = element ? gst_object_ref(element):NULL;
$$->last.name = NULL;
$$->last.pads = NULL;
$$->elements = element ? g_slist_prepend (NULL, element) : NULL;
g_free($1);
}
;
/*************************************************************
* Grammar explanation: (cont'd)
* the first and last elements of a _chain_ can be linked
* to a named _reference_ (with optional pads).
*
* fakesrc ! nameOfSinkElement.
* fakesrc ! nameOfSinkElement.Padname
* fakesrc ! nameOfSinkElement.Padname, anotherPad
* nameOfSource.Padname ! fakesink
**************************************************************/
chain: openchain link reference { $$ = $1;
$2->sink= $3;
$2->src = $1->last;
TRY_SETUP_LINK($2);
$$->last.element = NULL;
$$->last.name = NULL;
$$->last.pads = NULL;
}
;
openchain:
reference { $$ = gst_parse_chain_new ();
$$->last=$1;
$$->first.element = NULL;
$$->first.name = NULL;
$$->first.pads = NULL;
$$->elements = NULL;
}
;
reference: REF morepads {
gchar *padname = $1;
GSList *pads = $2;
if (padname) {
while (*padname != '.') padname++;
*padname = '\0';
padname++;
if (*padname != '\0')
pads = g_slist_prepend (pads, gst_parse_strdup (padname));
}
$$.element=NULL;
$$.name=$1;
$$.pads=pads;
}
;
/*************************************************************
* Grammar explanation: (cont'd)
* a _chainlist_ is just a list of _chain_s.
*
* You can specify _link_s with named
* _reference_ on each side. That
* works already after the explanations above.
* someSourceName.Pad ! someSinkName.
* someSourceName.Pad,anotherPad ! someSinkName.Apad,Bpad
*
* If a syntax error occurs, the already finished _chain_s
* and _links_ are kept intact.
*************************************************************/
chainlist: /* NOP */ { $$ = NULL; }
| chainlist chain { if ($1){
gst_parse_free_reference(&($1->last));
gst_parse_free_reference(&($2->first));
$2->first = $1->first;
$2->elements = g_slist_concat ($1->elements, $2->elements);
gst_parse_chain_free ($1);
}
$$ = $2;
}
| chainlist error { $$=$1;
GST_CAT_DEBUG (GST_CAT_PIPELINE,"trying to recover from syntax error");
SET_ERROR (graph->error, GST_PARSE_ERROR_SYNTAX, _("syntax error"));
}
;
/*************************************************************
* Grammar explanation: (cont'd)
* _bins_
*************************************************************/
assignments: /* NOP */ { $$ = NULL; }
| ASSIGNMENT assignments { $$ = g_slist_prepend ($2, $1); }
;
binopener: '(' { $$ = gst_parse_strdup(_("bin")); }
| BINREF { $$ = $1; }
;
bin: binopener assignments chainlist ')' {
chain_t *chain = $3;
GSList *walk;
GstBin *bin = (GstBin *) gst_element_factory_make ($1, NULL);
if (!chain) {
SET_ERROR (graph->error, GST_PARSE_ERROR_EMPTY_BIN,
_("specified empty bin \"%s\", not allowed"), $1);
chain = gst_parse_chain_new ();
chain->first.element = chain->last.element = NULL;
chain->first.name = chain->last.name = NULL;
chain->first.pads = chain->last.pads = NULL;
chain->elements = NULL;
}
if (!bin) {
add_missing_element(graph, $1);
SET_ERROR (graph->error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
_("no bin \"%s\", unpacking elements"), $1);
/* clear property-list */
g_slist_foreach ($2, (GFunc) gst_parse_strfree, NULL);
g_slist_free ($2);
$2 = NULL;
} else {
for (walk = chain->elements; walk; walk = walk->next )
gst_bin_add (bin, GST_ELEMENT (walk->data));
g_slist_free (chain->elements);
chain->elements = g_slist_prepend (NULL, bin);
}
$$ = chain;
/* set the properties now
* HINT: property-list cleared above, if bin==NULL
*/
for (walk = $2; walk; walk = walk->next)
gst_parse_element_set ((gchar *) walk->data,
GST_ELEMENT (bin), graph);
g_slist_free ($2);
gst_parse_strfree ($1);
}
;
/*************************************************************
* Grammar explanation: (cont'd)
* _graph_
*************************************************************/
graph: chainlist { $$ = graph;
$$->chain = $1;
if(!$1) {
SET_ERROR (graph->error, GST_PARSE_ERROR_EMPTY, _("empty pipeline not allowed"));
}
}
;
%%
static int
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;
}
GstElement *
priv_gst_parse_launch (const gchar *str, GError **error, GstParseContext *ctx,
GstParseFlags flags)
{
graph_t g;
gchar *dstr;
GSList *walk;
GstBin *bin = NULL;
GstElement *ret;
yyscan_t scanner;
g_return_val_if_fail (str != NULL, NULL);
g_return_val_if_fail (error == NULL || *error == NULL, NULL);
g.chain = NULL;
g.links = NULL;
g.error = error;
g.ctx = ctx;
g.flags = flags;
#ifdef __GST_PARSE_TRACE
GST_CAT_DEBUG (GST_CAT_PIPELINE, "TRACE: tracing enabled");
__strings = __chains = __links = 0;
#endif /* __GST_PARSE_TRACE */
/* g_print("Now scanning: %s\n", str); */
dstr = g_strdup (str);
priv_gst_parse_yylex_init (&scanner);
priv_gst_parse_yy_scan_string (dstr, scanner);
#if YYDEBUG
yydebug = 1;
#endif
if (yyparse (scanner, &g) != 0) {
SET_ERROR (error, GST_PARSE_ERROR_SYNTAX,
"Unrecoverable syntax error while parsing pipeline %s", str);
priv_gst_parse_yylex_destroy (scanner);
g_free (dstr);
goto error1;
}
priv_gst_parse_yylex_destroy (scanner);
g_free (dstr);
GST_CAT_DEBUG (GST_CAT_PIPELINE, "got %u elements and %u links",
g.chain ? g_slist_length (g.chain->elements) : 0,
g_slist_length (g.links));
/* ensure chain is not NULL */
if (!g.chain){
g.chain=gst_parse_chain_new ();
g.chain->elements=NULL;
g.chain->first.element=NULL;
g.chain->first.name=NULL;
g.chain->first.pads=NULL;
g.chain->last.element=NULL;
g.chain->last.name=NULL;
g.chain->last.pads=NULL;
};
/* ensure elements is not empty */
if(!g.chain->elements){
g.chain->elements= g_slist_prepend (NULL, NULL);
};
/* put all elements in our bin if necessary */
if(g.chain->elements->next){
bin = GST_BIN (gst_element_factory_make ("pipeline", NULL));
g_assert (bin);
for (walk = g.chain->elements; walk; walk = walk->next) {
if (walk->data != NULL)
gst_bin_add (bin, GST_ELEMENT (walk->data));
}
g_slist_free (g.chain->elements);
g.chain->elements = g_slist_prepend (NULL, bin);
}
ret = (GstElement *) g.chain->elements->data;
g_slist_free (g.chain->elements);
g.chain->elements=NULL;
if (GST_IS_BIN (ret))
bin = GST_BIN (ret);
gst_parse_free_chain (g.chain);
g.chain = NULL;
/* resolve and perform links */
for (walk = g.links; walk; walk = walk->next) {
link_t *l = (link_t *) walk->data;
int err;
err=gst_resolve_reference( &(l->src), ret);
if (err) {
if(-1==err){
SET_ERROR (error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
"No src-element named \"%s\" - omitting link", l->src.name);
}else{
/* probably a missing element which we've handled already */
SET_ERROR (error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
"No src-element found - omitting link");
}
gst_parse_free_link (l);
continue;
}
err=gst_resolve_reference( &(l->sink), ret);
if (err) {
if(-1==err){
SET_ERROR (error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
"No sink-element named \"%s\" - omitting link", l->src.name);
}else{
/* probably a missing element which we've handled already */
SET_ERROR (error, GST_PARSE_ERROR_NO_SUCH_ELEMENT,
"No sink-element found - omitting link");
}
gst_parse_free_link (l);
continue;
}
gst_parse_perform_link (l, &g);
}
g_slist_free (g.links);
out:
#ifdef __GST_PARSE_TRACE
GST_CAT_DEBUG (GST_CAT_PIPELINE,
"TRACE: %u strings, %u chains and %u links left", __strings, __chains,
__links);
if (__strings || __chains || __links) {
g_warning ("TRACE: %u strings, %u chains and %u links left", __strings,
__chains, __links);
}
#endif /* __GST_PARSE_TRACE */
return ret;
error1:
if (g.chain) {
gst_parse_free_chain (g.chain);
g.chain=NULL;
}
g_slist_foreach (g.links, (GFunc)gst_parse_free_link, NULL);
g_slist_free (g.links);
if (error)
g_assert (*error);
ret = NULL;
goto out;
}
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