diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0140ced82d4f1cdbab0b3dd3bb1021f140300357..2e68afa4f213a1475f7bd6e2ab4e457a0996dae9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2010-12-24 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ * objc.dg/gnu-api-2-class.m: Updated test to pass log_2 of the
+ alignment to class_addIvar, instead of the alignment itself.
+ * obj-c++.dg/gnu-api-2-class.mm: Same change.
+
2010-12-24 Nicola Pero <nicola.pero@meta-innovation.com>
* objc.dg/gnu-api-2-sel.m: Updated for renaming of sel_getType to
diff --git a/gcc/testsuite/obj-c++.dg/gnu-api-2-class.mm b/gcc/testsuite/obj-c++.dg/gnu-api-2-class.mm
index b86396f2144aa35bb4d50651f5ee86210a54c9ec..18c3393fa1e905de4dae416135639712db301d7a 100644
--- a/gcc/testsuite/obj-c++.dg/gnu-api-2-class.mm
+++ b/gcc/testsuite/obj-c++.dg/gnu-api-2-class.mm
@@ -62,6 +62,24 @@
- (id) mySelf;
@end
+/* Hack to calculate the log2 of a byte alignment. */
+unsigned char
+log_2_of (unsigned int x)
+{
+ unsigned char result = 0;
+
+ /* We count how many times we need to divide by 2 before we reach 1.
+ This algorithm is good enough for the small numbers (such as 8,
+ 16 or 64) that we have to deal with. */
+ while (x > 1)
+ {
+ x = x / 2;
+ result++;
+ }
+
+ return result;
+}
+
int main ()
{
/* Functions are tested in alphabetical order. */
@@ -74,15 +92,15 @@ int main ()
abort ();
if (! class_addIvar (new_class, "variable2_ivar", sizeof (id),
- __alignof__ (id), @encode (id)))
+ log_2_of (__alignof__ (id)), @encode (id)))
abort ();
if (! class_addIvar (new_class, "variable3_ivar", sizeof (unsigned char),
- __alignof__ (unsigned char), @encode (unsigned char)))
+ log_2_of (__alignof__ (unsigned char)), @encode (unsigned char)))
abort ();
if (! class_addIvar (new_class, "variable4_ivar", sizeof (unsigned long),
- __alignof__ (unsigned long), @encode (unsigned long)))
+ log_2_of (__alignof__ (unsigned long)), @encode (unsigned long)))
abort ();
objc_registerClassPair (new_class);
@@ -135,7 +153,7 @@ int main ()
abort ();
if (! class_addIvar (new_class, "variable_ivar", sizeof (id),
- __alignof__ (id), @encode (id)))
+ log_2_of (__alignof__ (id)), @encode (id)))
abort ();
if (! class_addMethod (new_class, @selector (setVariable:), method_getImplementation (method1),
diff --git a/gcc/testsuite/objc.dg/gnu-api-2-class.m b/gcc/testsuite/objc.dg/gnu-api-2-class.m
index ff0425966cdc5252e62ef58f49333855dbfc25c3..3302fccbb17aeb628ddf247b676296a9a1969087 100644
--- a/gcc/testsuite/objc.dg/gnu-api-2-class.m
+++ b/gcc/testsuite/objc.dg/gnu-api-2-class.m
@@ -62,6 +62,24 @@
- (id) mySelf;
@end
+/* Hack to calculate the log2 of a byte alignment. */
+unsigned char
+log_2_of (unsigned int x)
+{
+ unsigned char result = 0;
+
+ /* We count how many times we need to divide by 2 before we reach 1.
+ This algorithm is good enough for the small numbers (such as 8,
+ 16 or 64) that we have to deal with. */
+ while (x > 1)
+ {
+ x = x / 2;
+ result++;
+ }
+
+ return result;
+}
+
int main(int argc, void **args)
{
/* Functions are tested in alphabetical order. */
@@ -74,15 +92,15 @@ int main(int argc, void **args)
abort ();
if (! class_addIvar (new_class, "variable2_ivar", sizeof (id),
- __alignof__ (id), @encode (id)))
+ log_2_of (__alignof__ (id)), @encode (id)))
abort ();
if (! class_addIvar (new_class, "variable3_ivar", sizeof (unsigned char),
- __alignof__ (unsigned char), @encode (unsigned char)))
+ log_2_of (__alignof__ (unsigned char)), @encode (unsigned char)))
abort ();
if (! class_addIvar (new_class, "variable4_ivar", sizeof (unsigned long),
- __alignof__ (unsigned long), @encode (unsigned long)))
+ log_2_of (__alignof__ (unsigned long)), @encode (unsigned long)))
abort ();
objc_registerClassPair (new_class);
@@ -135,7 +153,7 @@ int main(int argc, void **args)
abort ();
if (! class_addIvar (new_class, "variable_ivar", sizeof (id),
- __alignof__ (id), @encode (id)))
+ log_2_of (__alignof__ (id)), @encode (id)))
abort ();
if (! class_addMethod (new_class, @selector (setVariable:), method_getImplementation (method1),
diff --git a/libobjc/ChangeLog b/libobjc/ChangeLog
index e028b58fc234f11fb5f5b8f10ec03c85b6fd9594..d8f23f74c9a1c4c2d981b83696c5226ae87d4d87 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,3 +1,10 @@
+2010-12-24 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ * objc/runtime.h (class_addIvar): Updated documentation. The
+ alignment is actually the log_2 of the alignment in bytes.
+ * ivars.c (class_addIvar): Corresponding change to the
+ implementation.
+
2010-12-24 Nicola Pero <nicola.pero@meta-innovation.com>
* objc/runtime.h (sel_getType): Renamed to sel_getTypeEncoding to
diff --git a/libobjc/ivars.c b/libobjc/ivars.c
index 7527df804d2505c3da8422e825b7da61eca9e10d..6111a03ea165d11542d55b87c7214b80bc16e41d 100644
--- a/libobjc/ivars.c
+++ b/libobjc/ivars.c
@@ -212,7 +212,7 @@ struct objc_ivar ** class_copyIvarList (Class class_, unsigned int *numberOfRetu
BOOL
class_addIvar (Class class_, const char * ivar_name, size_t size,
- unsigned char alignment, const char *type)
+ unsigned char log_2_of_alignment, const char *type)
{
struct objc_ivar_list *ivars;
@@ -270,6 +270,7 @@ class_addIvar (Class class_, const char * ivar_name, size_t size,
size. */
{
struct objc_ivar *ivar = &(ivars->ivar_list[ivars->ivar_count - 1]);
+ unsigned int alignment = 1 << log_2_of_alignment;
int misalignment;
ivar->ivar_name = objc_malloc (strlen (ivar_name) + 1);
diff --git a/libobjc/objc/runtime.h b/libobjc/objc/runtime.h
index 18fc8726dc4242e6a5f44dfdb6711eea7b78647b..9332f7be0692cf080af88e5eb9083f3b646a50e4 100644
--- a/libobjc/objc/runtime.h
+++ b/libobjc/objc/runtime.h
@@ -352,14 +352,16 @@ objc_EXPORT Ivar * class_copyIvarList (Class class_, unsigned int *numberOfRetur
using objc_allocateClassPair() and has not been registered with the
runtime using objc_registerClassPair() yet. You can not add
instance variables to classes already registered with the runtime.
- 'size' is the size of the instance variable, 'alignment' the
- alignment, and 'type' the type encoding of the variable type. You
- can use sizeof(), __alignof__() and @encode() to determine the
- right 'size', 'alignment' and 'type' for your instance variable.
- For example, to add an instance variable name "my_variable" and of
- type 'id', you can use:
-
- class_addIvar (class, "my_variable", sizeof (id), __alignof__ (id),
+ 'size' is the size of the instance variable, 'log_2_of_alignment'
+ the alignment as a power of 2 (so 0 means alignment to a 1 byte
+ boundary, 1 means alignment to a 2 byte boundary, 2 means alignment
+ to a 4 byte boundary, etc), and 'type' the type encoding of the
+ variable type. You can use sizeof(), log2(__alignof__()) and
+ @encode() to determine the right 'size', 'alignment' and 'type' for
+ your instance variable. For example, to add an instance variable
+ name "my_variable" and of type 'id', you can use:
+
+ class_addIvar (class, "my_variable", sizeof (id), log2 ( __alignof__ (id)),
@encode (id));
Return YES if the variable was added, and NO if not. In
@@ -368,7 +370,7 @@ objc_EXPORT Ivar * class_copyIvarList (Class class_, unsigned int *numberOfRetur
'type' is NULL, or 'size' is 0.
*/
objc_EXPORT BOOL class_addIvar (Class class_, const char * ivar_name, size_t size,
- unsigned char alignment, const char *type);
+ unsigned char log_2_of_alignment, const char *type);
/* Return the name of the property. Return NULL if 'property' is
NULL. */