In libobjc/: 2010-12-24 Nicola Pero <nicola.pero@meta-innovation.com>

In libobjc/:
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.

In gcc/testsuite/:
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.

From-SVN: r168230

6 files changed, 70 insertions, 18 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0140ced..2e68afa 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,11 @@
 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
 	sel_getTypeEncoding.  Test that sel_getTypeEncoding returns NULL
 	when called with a NULL argument.  Added test for
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 b86396f..18c3393 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 ff04259..3302fcc 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 e028b58..d8f23f7 100644
--- a/libobjc/ChangeLog
+++ b/libobjc/ChangeLog
@@ -1,5 +1,12 @@
 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
 	be consistent with method_getTypeEncoding and
 	ivar_getTypeEncoding.
diff --git a/libobjc/ivars.c b/libobjc/ivars.c
index 7527df8..6111a03 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 18fc872..9332f7b 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.  */