Changeset 2345 for lm-sensors/trunk/lib/general.c

Timestamp:

03/08/04 05:39:50 (9 years ago)

Author:

mmh

Message:

Patch by Philipp Thomas <pth@…>:

Current gcc versions warn when type punning is used, as this breaks the
strict aliasing analysis gcc 3.3 does by default. When checking the causes
for these warnings I discovered that sensors_malloc_array,
sensors_free_array, sensors_add_array_el and sensors_add_array_els in
lib/general.c all take a 'void **' for the list. This is plain wrong as
the C standard only allow 'char *' and 'void *' to alias any other type, so
if these functions should take a generic pointer, it *must* be a 'void *'
that's internally cast to a 'void **'.

The attached patch does this and adapts all places where these functions are
called. Note that when done correctly, no cast what-so-ever in the calling
code is needed.

The patch is against current lm_sensors2 cvs version.

Files:

• lm-sensors/trunk/lib/general.c (modified) (2 diffs)

lm-sensors/trunk/lib/general.c

@@ -28 +28 @@
 #define A_BUNCH 16
 
-void sensors_malloc_array(void **list, int *num_el, int *max_el, int el_size)
+void sensors_malloc_array(void *list, int *num_el, int *max_el, int el_size)
 {
-  *list = malloc(el_size*A_BUNCH);
-  if (! *list)
+  void **my_list = (void **)list;
+
+  *my_list = malloc(el_size*A_BUNCH);
+  if (! *my_list)
     sensors_fatal_error("sensors_malloc_array","Allocating new elements");
   *max_el = A_BUNCH;
@@ -37 +39 @@
 }
 
-void sensors_free_array(void **list, int *num_el, int *max_el)
+void sensors_free_array(void *list, int *num_el, int *max_el)
 {
-  free(*list);
-  *list = NULL;
+  void **my_list = (void **)list;
+
+  free(*my_list);
+  *my_list = NULL;
   *num_el = 0;
   *max_el = 0;
 }
 
-void sensors_add_array_el(const void *el, void **list, int *num_el,
+void sensors_add_array_el(const void *el, void *list, int *num_el,
                           int *max_el, int el_size)
 {
   int new_max_el;
+  void **my_list = (void *)list;
   if (*num_el + 1 > *max_el) {
     new_max_el = *max_el + A_BUNCH;
-    *list = realloc(*list,new_max_el * el_size);
-    if (! *list)
+    *my_list = realloc(*my_list,new_max_el * el_size);
+    if (! *my_list)
       sensors_fatal_error("sensors_add_array_el","Allocating new elements");
     *max_el = new_max_el;
   }
-  memcpy(((char *) *list) + *num_el * el_size, el, el_size);
+  memcpy(((char *) *my_list) + *num_el * el_size, el, el_size);
   (*num_el) ++;
 }
 
-void sensors_add_array_els(const void *els, int nr_els, void **list, 
+void sensors_add_array_els(const void *els, int nr_els, void *list, 
                            int *num_el, int *max_el, int el_size)
 {
   int new_max_el;
+  void **my_list = (void *)list;
   if (*num_el + nr_els > *max_el) {
     new_max_el = (*max_el + nr_els + A_BUNCH);
     new_max_el -= new_max_el % A_BUNCH;
-    *list = realloc(*list,new_max_el * el_size);
-    if (! *list)
+    *my_list = realloc(*my_list,new_max_el * el_size);
+    if (! *my_list)
       sensors_fatal_error("sensors_add_array_els","Allocating new elements");
     *max_el = new_max_el;
   }
-  memcpy(((char *)*list) + *num_el * el_size, els, el_size * nr_els);
+  memcpy(((char *)*my_list) + *num_el * el_size, els, el_size * nr_els);
   *num_el += nr_els;
 }