return exp;
/* The receiver is a function call that returns an id. Check if
- it is a call to objc_getClass, if so, pick up the class name. */
+ it is a call to objc_getClass, if so, pick up the class name.
+
+ This is required by the GNU runtime, which compiles
+
+ [NSObject alloc]
+
+ into
+
+ [objc_get_class ("NSObject") alloc];
+
+ and then, to check that the receiver responds to the +alloc
+ method, needs to be able to determine that the objc_get_class()
+ call returns the NSObject class and not just a generic Class
+ pointer.
+
+ But, traditionally this is enabled for all runtimes, not just the
+ GNU one, which means that the compiler is smarter than you'd
+ expect when dealing with objc_getClass(). For example, with the
+ Apple runtime, in the code
+
+ [objc_getClass ("NSObject") alloc];
+
+ the compiler will recognize the objc_getClass() call as special
+ (due to the code below) and so will know that +alloc is called on
+ the 'NSObject' class, and can perform the corresponding checks.
+
+ Programmers can disable this behaviour by casting the results of
+ objc_getClass() to 'Class' (this may seem weird because
+ objc_getClass() is already declared to return 'Class', but the
+ compiler treats it as a special function). This may be useful if
+ the class is never declared, and the compiler would complain
+ about a missing @interface for it. Then, you can do
+
+ [(Class)objc_getClass ("MyClassNeverDeclared") alloc];
+
+ to silence the warnings. */
if (TREE_CODE (receiver) == CALL_EXPR
&& (exp = CALL_EXPR_FN (receiver))
&& TREE_CODE (exp) == ADDR_EXPR
{
/* If 'rtype' is NULL_TREE at this point it means that
we have seen no @interface corresponding to that
- class name, only a @class declaration. So, we have a
- class name (class_tree) but no actual details of the
- class methods. We won't be able to check that the
- class responds to the method, and we will have to
- guess the method prototype. Emit a warning, then
- keep going (this will use any method with a matching
- name, as if the receiver was of type 'Class'). */
+ class name, only a @class declaration (alternatively,
+ this was a call such as [objc_getClass("SomeClass")
+ alloc], where we've never seen the @interface of
+ SomeClass). So, we have a class name (class_tree)
+ but no actual details of the class methods. We won't
+ be able to check that the class responds to the
+ method, and we will have to guess the method
+ prototype. Emit a warning, then keep going (this
+ will use any method with a matching name, as if the
+ receiver was of type 'Class'). */
warning (0, "@interface of class %qE not found", class_tree);
}
}
objc_registerClassPair (new_class);
{
- MySubClass *o = [[objc_getClass ("MySubSubClass") alloc] init];
+ MySubClass *o = [[(Class)objc_getClass ("MySubSubClass") alloc] init];
Ivar variable2 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable2_ivar");
Ivar variable3 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable3_ivar");
Ivar variable4 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable4_ivar");
/* Now, MySubClass2 is basically the same as MySubClass! We'll
use the variable and setVariable: methods on it. */
{
- MySubClass *o = (MySubClass *)[[objc_getClass ("MySubClass2") alloc] init];
+ MySubClass *o = (MySubClass *)[[(Class)objc_getClass ("MySubClass2") alloc] init];
[o setVariable: o];
objc_registerClassPair (new_class);
{
- MySubClass *o = [[objc_getClass ("MySubSubClass") alloc] init];
+ MySubClass *o = [[(Class)objc_getClass ("MySubSubClass") alloc] init];
Ivar variable2 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable2_ivar");
Ivar variable3 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable3_ivar");
Ivar variable4 = class_getInstanceVariable (objc_getClass ("MySubSubClass"), "variable4_ivar");
/* Now, MySubClass2 is basically the same as MySubClass! We'll
use the variable and setVariable: methods on it. */
{
- MySubClass *o = (MySubClass *)[[objc_getClass ("MySubClass2") alloc] init];
+ MySubClass *o = (MySubClass *)[[(Class)objc_getClass ("MySubClass2") alloc] init];
[o setVariable: o];
projects / gcc.git / commitdiff