added plist constructor with foreign obstack

made code more firm style

[r8176]

ir/adt/plist.c

@@ -21,25 +21,26 @@
  * @param list the list for which to allocate the element.
  * @return the newly allocated, uninitialized element.
  */
-static plist_element_t* allocate_element(plist_t* list) {
-	plist_element_t* newElement;
+static plist_element_t *allocate_element(plist_t* list) {
+	plist_element_t *new_element;
 
 	if (list->first_free_element != NULL) {
-		newElement               = list->first_free_element;
-		list->first_free_element = newElement->next;
-		newElement->next         = NULL;
+		new_element              = list->first_free_element;
+		list->first_free_element = new_element->next;
+		new_element->next        = NULL;
 	}
 	else {
-		newElement = obstack_alloc(&list->obst, sizeof(*newElement));
+		new_element = obstack_alloc(list->obst, sizeof(*new_element));
 	}
 
-	return newElement;
+	return new_element;
 }
 
 plist_t* plist_new(void) {
 	plist_t* list = xmalloc(sizeof(*list));
 
-	obstack_init(&list->obst);
+	obstack_init(list->obst);
+	list->foreign_obstack    = 0;
 	list->first_element      = NULL;
 	list->last_element       = NULL;
 	list->first_free_element = NULL;
@@ -48,14 +49,29 @@ plist_t* plist_new(void) {
 	return list;
 }
 
-void plist_free(plist_t* list) {
-	obstack_free(&list->obst, NULL);
+plist_t *plist_obstack_new(struct obstack *obst) {
+	plist_t *list = obstack_alloc(obst, sizeof(*list));
 
+	list->obst               = obst;
+	list->foreign_obstack    = 1;
 	list->first_element      = NULL;
 	list->last_element       = NULL;
 	list->first_free_element = NULL;
 	list->element_count      = 0;
-	xfree(list);
+
+	return list;
+}
+
+void plist_free(plist_t *list) {
+	list->first_element      = NULL;
+	list->last_element       = NULL;
+	list->first_free_element = NULL;
+	list->element_count      = 0;
+
+	if (! list->foreign_obstack) {
+		obstack_free(list->obst, NULL);
+		xfree(list);
+	}
 }
 
 void plist_insert_back(plist_t* list, void* value) {
@@ -128,22 +144,22 @@ void plist_insert_after(plist_t* list, plist_element_t* element, void* value) {
 	++list->element_count;
 }
 
-void plist_erase(plist_t* list, plist_element_t* element) {
-	plist_element_t* nextElement = element->next;
-	plist_element_t* prevElement = element->prev;
+void plist_erase(plist_t *list, plist_element_t *element) {
+	plist_element_t *next_element = element->next;
+	plist_element_t *prev_element = element->prev;
 
-	if (nextElement != NULL) {
-		nextElement->prev = prevElement;
+	if (next_element != NULL) {
+		next_element->prev = prev_element;
 	}
 	else {
-		list->last_element = prevElement;
+		list->last_element = prev_element;
 	}
 
-	if (prevElement != NULL) {
-		prevElement->next = nextElement;
+	if (prev_element != NULL) {
+		prev_element->next = next_element;
 	}
 	else {
-		list->first_element = nextElement;
+		list->first_element = next_element;
 	}
 
 	--list->element_count;
@@ -154,18 +170,18 @@ void plist_erase(plist_t* list, plist_element_t* element) {
 	list->first_free_element = element;
 }
 
-void plist_clear(plist_t* list) {
-	plist_element_t* currentElement = list->first_element;
+void plist_clear(plist_t *list) {
+	plist_element_t *curr_element = list->first_element;
 
-	while (currentElement != NULL) {
-		currentElement->prev = NULL;
-		currentElement       = currentElement->next;
+	while (curr_element != NULL) {
+		curr_element->prev = NULL;
+		curr_element       = curr_element->next;
 	}
 
-	currentElement = list->last_element;
+	curr_element = list->last_element;
 
-	if (currentElement != NULL) {
-		currentElement->next = list->first_free_element;
+	if (curr_element != NULL) {
+		curr_element->next = list->first_free_element;
 	}
 
 	list->first_free_element = list->first_element;

ir/adt/plist.h

@@ -26,19 +26,26 @@ struct _plist {
 	/**
 	 * The obstack used for all allocations.
 	 */
-	struct obstack obst;
+	struct obstack *obst;
+
+	/* Set to 1 if plist uses a foreign obstack  */
+	unsigned foreign_obstack : 1;
+
 	/**
 	 * First element in the list.
 	 */
 	plist_element_t *first_element;
+
 	/**
 	 * Last element in the list.
 	 */
 	plist_element_t *last_element;
+
 	/**
 	 * Current number of elements in the list.
 	 */
 	int element_count;
+
 	/**
 	 * First element in the free list.
 	 * Please note that the free list is a single linked list and all back
@@ -51,23 +58,31 @@ struct _plist {
  * An element in the pointer list.
  */
 struct _plist_element {
-	plist_element_t* next;
-	plist_element_t* prev;
-	void* data;
+	plist_element_t *next;
+	plist_element_t *prev;
+	void *data;
 };
 
 /**
  * Creates a new pointer list and initializes it.
  * @return The newly created pointer list.
  */
-plist_t* plist_new(void);
+plist_t *plist_new(void);
+
+/**
+ * Creates a new pointer list and initializes it.
+ * Uses the given obstack instead of creating one.
+ * @param obst  The obstack to use
+ * @return The newly created pointer list.
+ */
+plist_t *plist_obstack_new(struct obstack *obst);
 
 /**
  * Frees the passed pointer list.
  * After a call to this function all references to the list and any of
  * its elements are invalid.
  */
-void plist_free(plist_t* list);
+void plist_free(plist_t *list);
 
 /**
  * Returns the number of elements in a pointer list.
@@ -82,14 +97,14 @@ void plist_free(plist_t* list);
  * @param list the pointer list to append the new element to.
  * @param value the element value to append.
  */
-void plist_insert_back(plist_t* list, void* value);
+void plist_insert_back(plist_t *list, void *value);
 
 /**
  * Inserts an element at the front of a pointer list.
  * @param list the pointer list to prepend the new element to.
  * @param value the element value to prepend.
  */
-void plist_insert_front(plist_t* list, void* value);
+void plist_insert_front(plist_t *list, void *value);
 
 /**
  * Inserts an element into a pointer list before the specified element,
@@ -99,7 +114,7 @@ void plist_insert_front(plist_t* list, void* value);
  * 		be inserted. This element must be a part of @p list.
  * @param value the element value to insert.
  */
-void plist_insert_before(plist_t* list, plist_element_t* element, void* value);
+void plist_insert_before(plist_t *list, plist_element_t *element, void *value);
 
 /**
  * Inserts an element into a pointer list after the specified element,
@@ -109,21 +124,21 @@ void plist_insert_before(plist_t* list, plist_element_t* element, void* value);
  * 		be inserted. This element must be a part of @p list.
  * @param value the element value to insert.
  */
-void plist_insert_after(plist_t* list, plist_element_t* element, void* value);
+void plist_insert_after(plist_t *list, plist_element_t *element, void *value);
 
 /**
  * Erases the specified element from the pointer list.
- * @param list the pointer list from which the lement should be erased.
+ * @param list the pointer list from which the element should be erased.
  * @param element the list element to erase. This element must be a part
  * 		of @p list.
  */
-void plist_erase(plist_t* list, plist_element_t* element);
+void plist_erase(plist_t *list, plist_element_t *element);
 
 /**
  * Erases all elements from the specified pointer list.
- * @param list the pointer list that should be cleard.
+ * @param list the pointer list that should be cleared.
  */
-void plist_clear(plist_t* list);
+void plist_clear(plist_t *list);
 
 /**
  * Returns the first element of a pointer list.
@@ -143,7 +158,7 @@ void plist_clear(plist_t* list);
 
 /**
  * Checks whether a pointer list element has a successor or not.
- * @param element the list element that should be queried for existance
+ * @param element the list element that should be queried for existence
  * 		of a successor.
  * @return TRUE if @p element has a successor, otherwise FALSE.
  */
@@ -152,7 +167,7 @@ void plist_clear(plist_t* list);
 
 /**
  * Checks whether a pointer list element has a predecessor or not.
- * @param element the list element that should be queried for existance
+ * @param element the list element that should be queried for existence
  * 		of a predecessor.
  * @return TRUE if @p element has a successor, otherwise FALSE.
  */