ptrlist: change return value of linearize_ptr_list()/ptr_list_to_array()

The function linearize_ptr_list() is annoying to use because it
returns the number of elements put in the array. So, if you need
to know if the list contained the expected number of entries,
you need to allocate an array with one extra entry and check
that the return value is one less than this size.

So, change the function to return the total number of entries
in the list. In other words, the return value corresponds now to
the number of entries that could be copied if the size would be
unlimited, much like it's done for snprintf().
The number of entries effectively copied stays, of course,
limited by the size specified for the array.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

ptrlist.c

@@ -154,10 +154,10 @@ void *ptr_list_nth_entry(struct ptr_list *list, unsigned int idx)
 // @head: the list to be linearized
 // @arr: a ``void*`` array to fill with @head's entries
 // @max: the maximum number of entries to store into @arr
-// @return: the number of entries linearized.
+// @return: the number of entries in the list.
 //
 // Linearize the entries of a list up to a total of @max,
-// and return the nr of entries linearized.
+// and return the number of entries in the list.
 //
 // The array to linearize into (@arr) should really
 // be ``void *x[]``, but we want to let people fill in any kind
@@ -170,14 +170,14 @@ int linearize_ptr_list(struct ptr_list *head, void **arr, int max)
 
 		do {
 			int i = list->nr;
+			nr += i;
+			if (max == 0)
+				continue;
 			if (i > max) 
 				i = max;
 			memcpy(arr, list->list, i*sizeof(void *));
 			arr += i;
-			nr += i;
 			max -= i;
-			if (!max)
-				break;
 		} while ((list = list->next) != head);
 	}
 	return nr;

simplify.c

@@ -108,15 +108,15 @@ static int get_phisources(struct instruction *sources[], int nbr, struct instruc
 static int if_convert_phi(struct instruction *insn)
 {
 	struct instruction *array[2];
-	struct basic_block *parents[3];
+	struct basic_block *parents[2];
 	struct basic_block *bb, *bb1, *bb2, *source;
 	struct instruction *br;
 	pseudo_t p1, p2;
 
 	bb = insn->bb;
 	if (get_phisources(array, 2, insn))
 		return 0;
-	if (ptr_list_to_array(bb->parents, parents, 3) != 2)
+	if (ptr_list_to_array(bb->parents, parents, 2) != 2)
 		return 0;
 	p1 = array[0]->phi_src;
 	bb1 = array[0]->bb;