* README: Document signed integer overflow situation more

[gnulib.git] / lib / gl_carray_list.c

diff --git a/lib/gl_carray_list.c b/lib/gl_carray_list.c
index 5be0d07..7630c2a 100644 (file)
--- a/lib/gl_carray_list.c
+++ b/lib/gl_carray_list.c
@@ -61,8 +61,7 @@ gl_carray_create_empty (gl_list_implementation_t implementation,
                       gl_listelement_hashcode_fn hashcode_fn,
                       bool allow_duplicates)
 {
-  struct gl_list_impl *list =
-    (struct gl_list_impl *) xmalloc (sizeof (struct gl_list_impl));
+  struct gl_list_impl *list = XMALLOC (struct gl_list_impl);
 
   list->base.vtable = implementation;
   list->base.equals_fn = equals_fn;
@@ -83,8 +82,7 @@ gl_carray_create (gl_list_implementation_t implementation,
                 bool allow_duplicates,
                 size_t count, const void **contents)
 {
-  struct gl_list_impl *list =
-    (struct gl_list_impl *) xmalloc (sizeof (struct gl_list_impl));
+  struct gl_list_impl *list = XMALLOC (struct gl_list_impl);
 
   list->base.vtable = implementation;
   list->base.equals_fn = equals_fn;
@@ -92,8 +90,7 @@ gl_carray_create (gl_list_implementation_t implementation,
   list->base.allow_duplicates = allow_duplicates;
   if (count > 0)
     {
-      list->elements =
-       (const void **) xmalloc (count * sizeof (const void *));
+      list->elements = XNMALLOC (count, const void *);
       memcpy (list->elements, contents, count * sizeof (const void *));
     }
   else
@@ -185,16 +182,22 @@ gl_carray_set_at (gl_list_t list, size_t position, const void *elt)
 }
 
 static size_t
-gl_carray_indexof (gl_list_t list, const void *elt)
+gl_carray_indexof_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                          const void *elt)
 {
   size_t count = list->count;
-  if (count > 0)
+
+  if (!(start_index <= end_index && end_index <= count))
+    /* Invalid arguments.  */
+    abort ();
+
+  if (start_index < end_index)
     {
       gl_listelement_equals_fn equals = list->base.equals_fn;
       size_t allocated = list->allocated;
       size_t i_end;
 
-      i_end = list->offset + list->count;
+      i_end = list->offset + end_index;
       if (i_end >= allocated)
        i_end -= allocated;
 
@@ -202,7 +205,11 @@ gl_carray_indexof (gl_list_t list, const void *elt)
        {
          size_t i;
 
-         for (i = list->offset;;)
+         i = list->offset + start_index;
+         if (i >= allocated) /* can only happen if start_index > 0 */
+           i -= allocated;
+
+         for (;;)
            {
              if (equals (elt, list->elements[i]))
                return (i >= list->offset ? i : i + allocated) - list->offset;
@@ -217,7 +224,11 @@ gl_carray_indexof (gl_list_t list, const void *elt)
        {
          size_t i;
 
-         for (i = list->offset;;)
+         i = list->offset + start_index;
+         if (i >= allocated) /* can only happen if start_index > 0 */
+           i -= allocated;
+
+         for (;;)
            {
              if (elt == list->elements[i])
                return (i >= list->offset ? i : i + allocated) - list->offset;
@@ -233,9 +244,10 @@ gl_carray_indexof (gl_list_t list, const void *elt)
 }
 
 static gl_list_node_t
-gl_carray_search (gl_list_t list, const void *elt)
+gl_carray_search_from_to (gl_list_t list, size_t start_index, size_t end_index,
+                         const void *elt)
 {
-  size_t index = gl_carray_indexof (list, elt);
+  size_t index = gl_carray_indexof_from_to (list, start_index, end_index, elt);
   return INDEX_TO_NODE (index);
 }
 
@@ -501,7 +513,7 @@ gl_carray_remove_node (gl_list_t list, gl_list_node_t node)
 static bool
 gl_carray_remove (gl_list_t list, const void *elt)
 {
-  size_t position = gl_carray_indexof (list, elt);
+  size_t position = gl_carray_indexof_from_to (list, 0, list->count, elt);
   if (position == (size_t)(-1))
     return false;
   else
@@ -528,6 +540,10 @@ gl_carray_iterator (gl_list_t list)
   result.count = list->count;
   result.i = 0;
   result.j = list->count;
+#ifdef lint
+  result.p = 0;
+  result.q = 0;
+#endif
 
   return result;
 }
@@ -545,6 +561,10 @@ gl_carray_iterator_from_to (gl_list_t list, size_t start_index, size_t end_index
   result.count = list->count;
   result.i = start_index;
   result.j = end_index;
+#ifdef lint
+  result.p = 0;
+  result.q = 0;
+#endif
 
   return result;
 }
@@ -587,19 +607,19 @@ gl_carray_iterator_free (gl_list_iterator_t *iterator)
 /* ---------------------- Sorted gl_list_t Data Type ---------------------- */
 
 static size_t
-gl_carray_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
-                             const void *elt)
+gl_carray_sortedlist_indexof_from_to (gl_list_t list,
+                                     gl_listelement_compar_fn compar,
+                                     size_t low, size_t high,
+                                     const void *elt)
 {
-  size_t count = list->count;
-
-  if (count > 0)
+  if (!(low <= high && high <= list->count))
+    /* Invalid arguments.  */
+    abort ();
+  if (low < high)
     {
-      size_t low = 0;
-      size_t high = count;
-
       /* At each loop iteration, low < high; for indices < low the values
         are smaller than ELT; for indices >= high the values are greater
-        than ELT.  So, if the element occurs in the list, is at
+        than ELT.  So, if the element occurs in the list, it is at
         low <= position < high.  */
       do
        {
@@ -628,7 +648,7 @@ gl_carray_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
                 low <= position <= high.  */
              while (low < high)
                {
-                 size_t mid2 = low + (high - low) / 2; /* low <= mid < high */
+                 size_t mid2 = low + (high - low) / 2; /* low <= mid2 < high */
                  size_t i_mid2;
                  int cmp2;
 
@@ -659,11 +679,31 @@ gl_carray_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
   return (size_t)(-1);
 }
 
+static size_t
+gl_carray_sortedlist_indexof (gl_list_t list, gl_listelement_compar_fn compar,
+                             const void *elt)
+{
+  return gl_carray_sortedlist_indexof_from_to (list, compar, 0, list->count,
+                                              elt);
+}
+
+static gl_list_node_t
+gl_carray_sortedlist_search_from_to (gl_list_t list,
+                                    gl_listelement_compar_fn compar,
+                                    size_t low, size_t high,
+                                    const void *elt)
+{
+  size_t index =
+    gl_carray_sortedlist_indexof_from_to (list, compar, low, high, elt);
+  return INDEX_TO_NODE (index);
+}
+
 static gl_list_node_t
 gl_carray_sortedlist_search (gl_list_t list, gl_listelement_compar_fn compar,
                             const void *elt)
 {
-  size_t index = gl_carray_sortedlist_indexof (list, compar, elt);
+  size_t index =
+    gl_carray_sortedlist_indexof_from_to (list, compar, 0, list->count, elt);
   return INDEX_TO_NODE (index);
 }
 
@@ -724,8 +764,8 @@ const struct gl_list_implementation gl_carray_list_implementation =
     gl_carray_previous_node,
     gl_carray_get_at,
     gl_carray_set_at,
-    gl_carray_search,
-    gl_carray_indexof,
+    gl_carray_search_from_to,
+    gl_carray_indexof_from_to,
     gl_carray_add_first,
     gl_carray_add_last,
     gl_carray_add_before,
@@ -740,7 +780,9 @@ const struct gl_list_implementation gl_carray_list_implementation =
     gl_carray_iterator_next,
     gl_carray_iterator_free,
     gl_carray_sortedlist_search,
+    gl_carray_sortedlist_search_from_to,
     gl_carray_sortedlist_indexof,
+    gl_carray_sortedlist_indexof_from_to,
     gl_carray_sortedlist_add,
     gl_carray_sortedlist_remove
   };