CSS: new struct css_selector_set

src/document/css/apply.c

@@ -117,7 +117,7 @@ static css_applier_T css_appliers[CSS_PT_LAST] = {
 static void
 examine_element(struct html_context *html_context, struct css_selector *base,
 		enum css_selector_type seltype, enum css_selector_relation rel,
-                struct list_head *selectors, struct html_element *element)
+		struct css_selector_set *selectors, struct html_element *element)
 {
 	struct css_selector *selector;
 
@@ -129,7 +129,7 @@ examine_element(struct html_context *html_context, struct css_selector *base,
 
  	DBG("examine_element(%p, %s, %d, %d, %p, %.*s);", html_context, base->name, seltype, rel, selectors, element->namelen, element->name);
 #define dbginfo(sel, type_, base) \
-	dbg_has_leaves = !list_empty(sel->leaves), \
+	dbg_has_leaves = !css_selector_set_empty(&sel->leaves), \
 	dbg_has_properties = !list_empty(sel->properties), \
 	DBG("Matched selector %s (rel %d type %d [m%d])! Children %p !!%d, props !!%d", sel->name, sel->relation, sel->type, sel->type == type_, &sel->leaves, dbg_has_leaves, dbg_has_properties)
 #else

src/document/css/css.c

@@ -112,7 +112,7 @@ import_default_css(void)
 {
 	unsigned char *url = get_opt_str("document.css.stylesheet");
 
-	if (!list_empty(default_stylesheet.selectors))
+	if (!css_selector_set_empty(&default_stylesheet.selectors))
 		done_css_stylesheet(&default_stylesheet);
 
 	if (!*url) return;

src/document/css/parser.c

@@ -170,21 +170,21 @@ struct selector_pkg {
 	struct css_selector *selector;
 };
 
-/** Move a CSS selector and its leaves into a new list.  If a similar
- * selector already exists in the list, merge them.
+/** Move a CSS selector and its leaves into a new set.  If a similar
+ * selector already exists in the set, merge them.
  *
  * \param sels
- *   The list to which \a selector should be moved.  Must not be NULL.
+ *   The set to which \a selector should be moved.  Must not be NULL.
  * \param selector
  *   The selector that should be moved.  Must not be NULL.  If it is
- *   already in some list, this function removes it from there.
+ *   already in some set, this function removes it from there.
  * \param watch
  *   This function updates \a *watch if it merges that selector into
  *   another one.  \a watch must not be NULL but \a *watch may be.
  *
  * \return \a selector or the one into which it was merged.  */
 static struct css_selector *
-reparent_selector(struct list_head *sels, struct css_selector *selector,
+reparent_selector(struct css_selector_set *sels, struct css_selector *selector,
                   struct css_selector **watch)
 {
 	struct css_selector *twin = find_css_selector(sels, selector->type,
@@ -194,8 +194,8 @@ reparent_selector(struct list_head *sels, struct css_selector *selector,
 	if (twin) {
 		merge_css_selectors(twin, selector);
 		/* Reparent leaves. */
-		while (selector->leaves.next != &selector->leaves) {
-			struct css_selector *leaf = selector->leaves.next;
+		while (!css_selector_set_empty(&selector->leaves)) {
+			struct css_selector *leaf = css_selector_set_front(&selector->leaves);
 
 			reparent_selector(&twin->leaves, leaf, watch);
 		}
@@ -203,8 +203,9 @@ reparent_selector(struct list_head *sels, struct css_selector *selector,
 			*watch = twin;
 		done_css_selector(selector);
 	} else {
-		if (selector->next) del_from_list(selector);
-		add_to_list(*sels, selector);
+		if (css_selector_is_in_set(selector))
+			del_css_selector_from_set(selector);
+		add_css_selector_to_set(selector, sels);
 	}
 
 	return twin ? twin : selector;
@@ -368,9 +369,9 @@ css_parse_selector(struct css_stylesheet *css, struct scanner *scanner,
 				/* The situation is like: 'div p#x', now it was
 				 * 'p -> div', but we need to redo that as
 				 * '(p ->) #x -> div'. */
-				del_from_list(last_chained_selector);
-				add_to_list(selector->leaves,
-				            last_chained_selector);
+				del_css_selector_from_set(last_chained_selector);
+				add_css_selector_to_set(last_chained_selector,
+							&selector->leaves);
 			}
 
 			if (pkg->selector == base_sel) {
@@ -403,7 +404,8 @@ css_parse_selector(struct css_stylesheet *css, struct scanner *scanner,
 			if (!selector) continue;
 
 			assert(prev_element_selector);
-			add_to_list(selector->leaves, prev_element_selector);
+			add_css_selector_to_set(prev_element_selector,
+						&selector->leaves);
 			last_chained_selector = prev_element_selector;
 
 			prev_element_selector->relation = reltype;
@@ -496,7 +498,7 @@ css_parse_ruleset(struct css_stylesheet *css, struct scanner *scanner)
 		 * because GCC 4.1 "warning: operation on `errfile'
 		 * may be undefined" breaks the build with -Werror.  */
 		int dbg_has_properties = !list_empty(properties);
-		int dbg_has_leaves = !list_empty(pkg->selector->leaves);
+		int dbg_has_leaves = !css_selector_set_empty(&pkg->selector->leaves);
 
 		DBG("Binding properties (!!%d) to selector %s (type %d, relation %d, children %d)",
 			dbg_has_properties,

src/document/css/stylesheet.c

@@ -25,7 +25,7 @@
 
 
 struct css_selector *
-find_css_selector(struct list_head *sels, enum css_selector_type type,
+find_css_selector(struct css_selector_set *sels, enum css_selector_type type,
                   enum css_selector_relation rel,
                   const unsigned char *name, int namelen)
 {
@@ -33,7 +33,7 @@ find_css_selector(struct list_head *sels, enum css_selector_type type,
 
 	assert(sels && name);
 
-	foreach (selector, *sels) {
+	foreach_css_selector (selector, sels) {
 		if (type != selector->type || rel != selector->relation)
 			continue;
 		if (strlcasecmp(name, namelen, selector->name, -1))
@@ -45,7 +45,7 @@ find_css_selector(struct list_head *sels, enum css_selector_type type,
 }
 
 struct css_selector *
-init_css_selector(struct list_head *sels, enum css_selector_type type,
+init_css_selector(struct css_selector_set *sels, enum css_selector_type type,
                   unsigned char *name, int namelen)
 {
 	struct css_selector *selector;
@@ -54,7 +54,7 @@ init_css_selector(struct list_head *sels, enum css_selector_type type,
 	if (!selector) return NULL;
 
 	selector->relation = CSR_ROOT; /* Default */
-	init_list(selector->leaves);
+	init_css_selector_set(&selector->leaves);
 
 	selector->type = type;
 	init_list(selector->properties);
@@ -64,6 +64,7 @@ init_css_selector(struct list_head *sels, enum css_selector_type type,
 			namelen = strlen(name);
 		selector->name = memacpy(name, namelen);
 		if (!selector->name) {
+			done_css_selector_set(&selector->leaves);
 			mem_free(selector);
 			return NULL;
 		}
@@ -71,14 +72,14 @@ init_css_selector(struct list_head *sels, enum css_selector_type type,
 	}
 
 	if (sels) {
-		add_to_list(*sels, selector);
+		add_css_selector_to_set(selector, sels);
 	}
 
 	return selector;
 }
 
 struct css_selector *
-get_css_selector(struct list_head *sels, enum css_selector_type type,
+get_css_selector(struct css_selector_set *sels, enum css_selector_type type,
                  enum css_selector_relation rel,
                  unsigned char *name, int namelen)
 {
@@ -173,23 +174,30 @@ merge_css_selectors(struct css_selector *sel1, struct css_selector *sel2)
 void
 done_css_selector(struct css_selector *selector)
 {
-	while (selector->leaves.next != &selector->leaves) {
-		done_css_selector(selector->leaves.next);
-	}
+	done_css_selector_set(&selector->leaves);
 
-	if (selector->next) del_from_list(selector);
+	if (css_selector_is_in_set(selector))
+		del_css_selector_from_set(selector);
 	free_list(selector->properties);
 	mem_free_if(selector->name);
 	mem_free(selector);
 }
 
+void
+done_css_selector_set(struct css_selector_set *set)
+{
+	while (!css_selector_set_empty(set)) {
+		done_css_selector(css_selector_set_front(set));
+	}
+}
+
 #ifdef DEBUG_CSS
 void
-dump_css_selector_tree_iter(struct list_head *sels, int level)
+dump_css_selector_tree_iter(struct css_selector_set *sels, int level)
 {
 	struct css_selector *sel;
 
-	foreach (sel, *sels) {
+	foreach_css_selector (sel, sels) {
 		struct css_property *prop;
 
 		fprintf(stderr, "%*s +- [%s] type %d rel %d props",
@@ -204,7 +212,7 @@ dump_css_selector_tree_iter(struct list_head *sels, int level)
 }
 
 void
-dump_css_selector_tree(struct list_head *sels)
+dump_css_selector_tree(struct css_selector_set *sels)
 {
 	dump_css_selector_tree_iter(sels, 0);
 }
@@ -221,7 +229,7 @@ init_css_stylesheet(css_stylesheet_importer_T importer, void *import_data)
 		return NULL;
 	css->import = importer;
 	css->import_data = import_data;
-	init_list(css->selectors);
+	init_css_selector_set(&css->selectors);
 	return css;
 }
 
@@ -230,7 +238,7 @@ mirror_css_stylesheet(struct css_stylesheet *css1, struct css_stylesheet *css2)
 {
 	struct css_selector *selector;
 
-	foreach (selector, css1->selectors) {
+	foreach_css_selector (selector, &css1->selectors) {
 		clone_css_selector(css2, selector);
 	}
 }
@@ -261,7 +269,7 @@ merge_css_stylesheets(struct css_stylesheet *css1,
 	 * O(N^2) where we could be much smarter (ie. sort it once and then
 	 * always be O(N)). */
 
-	foreach (selector, css2->selectors) {
+	foreach_css_selector (selector, &css2->selectors) {
 		struct css_selector *origsel;
 
 		origsel = find_css_selector(&css1->selectors, selector->name,
@@ -278,7 +286,5 @@ merge_css_stylesheets(struct css_stylesheet *css1,
 void
 done_css_stylesheet(struct css_stylesheet *css)
 {
-	while (!list_empty(css->selectors)) {
-		done_css_selector(css->selectors.next);
-	}
+	done_css_selector_set(&css->selectors);
 }

src/document/css/stylesheet.h

@@ -31,6 +31,29 @@
  * in particular. Is it obsolete now when we grok 'td.foo p#x>a:hover' without
  * hesitation? --pasky */
 
+/* A set of struct css_selector.  This is currently represented as a
+ * list but that may be changed later.  Therefore please try not to
+ * access the contents directly; instead define new wrapper macros.
+ *
+ * According to CSS2 section 7.1 "Cascading order", if two rules have
+ * the same weight, then the latter specified wins.  Regardless, the
+ * order of rules need not be represented in struct css_selector_set,
+ * because all rules for the same selector have already been merged
+ * into one struct css_selector.  */
+struct css_selector_set {
+#ifdef CONFIG_DEBUG
+	/* Cause a crash if struct css_selector_set * is cast to
+	 * struct list_head *.  */
+	char dummy;
+#endif
+	
+	struct list_head list;	/* -> struct css_selector */
+};
+#ifdef CONFIG_DEBUG
+# define INIT_CSS_SELECTOR_SET(set) { 0, { D_LIST_HEAD(set.list) } }
+#else
+# define INIT_CSS_SELECTOR_SET(set) { { D_LIST_HEAD(set.list) } }
+#endif
 
 /* The {struct css_selector} is used for mapping elements (or nodes) in the
  * document structure to properties. See README for some hints about how the
@@ -49,7 +72,7 @@ struct css_selector {
 		CSR_ANCESTOR, /* Ancestor, i.e. the "p" in "p a". */
 		CSR_PARENT, /* Direct parent, i.e. the "div" in "div>img". */
 	} relation;
-	struct list_head leaves; /* -> struct css_selector */
+	struct css_selector_set leaves;
 
 	enum css_selector_type {
 		CST_ELEMENT,
@@ -79,16 +102,16 @@ struct css_stylesheet {
 	/* The import callback's data. */
 	void *import_data;
 
-	/* The list of basic element selectors (which can then somehow
+	/* The set of basic element selectors (which can then somehow
 	 * tree up on inside). */
-	struct list_head selectors; /* -> struct css_selector */
+	struct css_selector_set selectors;
 
 	/* How deeply nested are we. Limited by MAX_REDIRECTS. */
 	int import_level;
 };
 
 #define INIT_CSS_STYLESHEET(css, import) \
-	{ import, NULL, { D_LIST_HEAD(css.selectors) } }
+	{ import, NULL, INIT_CSS_SELECTOR_SET(css.selectors) }
 
 /* Dynamically allocates a stylesheet. */
 struct css_stylesheet *init_css_stylesheet(css_stylesheet_importer_T importer,
@@ -105,8 +128,8 @@ void done_css_stylesheet(struct css_stylesheet *css);
 
 
 /* Returns a new freshly made selector adding it to the given selector
- * list, or NULL. */
-struct css_selector *get_css_selector(struct list_head *selector_list,
+ * set, or NULL. */
+struct css_selector *get_css_selector(struct css_selector_set *set,
                                       enum css_selector_type type,
                                       enum css_selector_relation rel,
                                       unsigned char *name, int namelen);
@@ -116,8 +139,8 @@ struct css_selector *get_css_selector(struct list_head *selector_list,
 	                 type, rel, name, namelen)
 
 /* Looks up the selector of the name @name and length @namelen in the
- * given list of selectors. */
-struct css_selector *find_css_selector(struct list_head *selector_list,
+ * given set of selectors. */
+struct css_selector *find_css_selector(struct css_selector_set *set,
                                        enum css_selector_type type,
                                        enum css_selector_relation rel,
                                        const unsigned char *name, int namelen);
@@ -127,7 +150,7 @@ struct css_selector *find_css_selector(struct list_head *selector_list,
 
 /* Initialize the selector structure. This is a rather low-level function from
  * your POV. */
-struct css_selector *init_css_selector(struct list_head *selector_list,
+struct css_selector *init_css_selector(struct css_selector_set *set,
                                        enum css_selector_type type,
                                        unsigned char *name, int namelen);
 
@@ -141,9 +164,18 @@ void merge_css_selectors(struct css_selector *sel1, struct css_selector *sel2);
 /* Destroy a selector. done_css_stylesheet() normally does that for you. */
 void done_css_selector(struct css_selector *selector);
 
+#define init_css_selector_set(set) init_list((set)->list)
+void done_css_selector_set(struct css_selector_set *set);
+#define css_selector_set_empty(set) list_empty((set)->list)
+#define css_selector_set_front(set) ((struct css_selector *) ((set)->list.next))
+#define del_css_selector_from_set(selector) del_from_list(selector)
+#define add_css_selector_to_set(selector, set) add_to_list((set)->list, (selector))
+#define css_selector_is_in_set(selector) ((selector)->next != NULL)
+#define foreach_css_selector(selector, set) foreach (selector, (set)->list)
+
 #ifdef DEBUG_CSS
 /* Dumps the selector tree to stderr. */
-void dump_css_selector_tree(struct list_head *selector_list);
+void dump_css_selector_tree(struct css_selector_set *set);
 #endif
 
 #endif

src/document/html/parser.c

@@ -771,7 +771,7 @@ init_html_parser(struct uri *uri, struct document_options *options,
 
 #ifdef CONFIG_CSS
 	html_context->css_styles.import = import_css_stylesheet;
-	init_list(html_context->css_styles.selectors);
+	init_css_selector_set(&html_context->css_styles.selectors);
 #endif
 
 	init_list(html_context->stack);