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ObjC/ObjC++: Another fix for detection of duplicate methods
- From: Nicola Pero <nicola dot pero at meta-innovation dot com>
- To: gcc-patches at gnu dot org
- Date: Thu, 30 Dec 2010 20:52:37 +0100
- Subject: ObjC/ObjC++: Another fix for detection of duplicate methods
This patch fixes comparison of protocol qualifier lists in types when
the compiler is trying
to detect duplicate methods in an interface, category or protocol.
The main case that didn't work is --
@protocol A
@end
@protocol B <A>
@end
@interface MyClass
- (void) method: (id <A>)x;
- (void) method: (id <B>)x;
@end
without this patch, GCC incorrectly thinks that the two methods are
identical including the types (!!) because
of a bug in the protocol comparison code, and does not emit any
warning or error. (also note that if you
swap the order of the two methods, GCC suddenly realizes that they are
different and produces an error). ;-)
The other case that didn't work is a bit more subtle, and I found it
in the clang testsuite (this is
a shrinked down testcase of my own, but the concept is the same):
@protocol A;
@interface MyClass
- (void) method: (id <A, A>)x;
- (void) method: (id <A>)x;
@end
in this testcase, they seem to assume that "id <A, A>" is a valid type
(and, in fairness, GCC accepts it
as valid too) and (obviously) identical to "id <A>" and hence the two
methods have the same types
and so no warning or error should be generated.
But GCC would get confused by the duplicated protocol qualifier; it
would compare the length of the
protocol list between "id <A, A>" and "id <A>", and conclude they are
different types, and produce an error.
That is a bug - if we accept duplicated protocols in protocol
qualifier lists (which we have always done
and I guess we'll keep doing - clang does it too) then we need to be
able to compare them properly.
Anyway, this patch fixes the comparison of protocol lists in all these
cases (testcases included). With this
patch, it all seems to work quite well.
Ok to commit ?
Thanks
Index: objc/objc-act.c
===================================================================
--- objc/objc-act.c (revision 168350)
+++ objc/objc-act.c (working copy)
@@ -11925,9 +11925,8 @@ start_method_def (tree method)
really_start_method (objc_method_context, parm_info);
}
-/* Return 1 if TYPE1 is equivalent to TYPE2
- for purposes of method overloading. */
-
+/* Return 1 if TYPE1 is equivalent to TYPE2 for purposes of method
+ overloading. */
static int
objc_types_are_equivalent (tree type1, tree type2)
{
@@ -11941,6 +11940,7 @@ objc_types_are_equivalent (tree type1, t
if (TYPE_MAIN_VARIANT (type1) != TYPE_MAIN_VARIANT (type2))
return 0;
+ /* Compare the protocol lists. */
type1 = (TYPE_HAS_OBJC_INFO (type1)
? TYPE_OBJC_PROTOCOL_LIST (type1)
: NULL_TREE);
@@ -11948,14 +11948,34 @@ objc_types_are_equivalent (tree type1, t
? TYPE_OBJC_PROTOCOL_LIST (type2)
: NULL_TREE);
- if (list_length (type1) == list_length (type2))
+ /* If there are no protocols (most common case), the types are
+ identical. */
+ if (type1 == NULL_TREE && type2 == NULL_TREE)
+ return 1;
+
+ /* If one has protocols, and the other one hasn't, they are not
+ identical. */
+ if ((type1 == NULL_TREE && type2 != NULL_TREE)
+ || (type1 != NULL_TREE && type2 == NULL_TREE))
+ return 0;
+ else
{
- for (; type2; type2 = TREE_CHAIN (type2))
- if (!lookup_protocol_in_reflist (type1, TREE_VALUE (type2)))
+ /* Else, both have protocols, and we need to do the full
+ comparison. It is possible that either type1 or type2
+ contain some duplicate protocols in the list, so we can't
+ even just compare list_length as a first check. */
+ tree t;
+
+ for (t = type2; t; t = TREE_CHAIN (t))
+ if (!lookup_protocol_in_reflist (type1, TREE_VALUE (t)))
+ return 0;
+
+ for (t = type1; t; t = TREE_CHAIN (t))
+ if (!lookup_protocol_in_reflist (type2, TREE_VALUE (t)))
return 0;
+
return 1;
}
- return 0;
}
/* Return 1 if TYPE1 has the same size and alignment as TYPE2. */
Index: objc/ChangeLog
===================================================================
--- objc/ChangeLog (revision 168350)
+++ objc/ChangeLog (working copy)
@@ -1,5 +1,12 @@
2010-12-30 Nicola Pero <nicola.pero@meta-innovation.com>
+ * objc-act.c (objc_types_are_equivalent): Fixed comparing
protocol
+ lists. Check them two-ways to fix comparisons when one protocol
+ implements the other one, or when one list contains duplicated
+ protocols.
+
+2010-12-30 Nicola Pero <nicola.pero@meta-innovation.com>
+
* objc-act.c (objc_add_method): When emitting an error
because a
method with the same name but conflicting types is found in the
same class or category interface, print a note with the
location
Index: testsuite/ChangeLog
===================================================================
--- testsuite/ChangeLog (revision 168350)
+++ testsuite/ChangeLog (working copy)
@@ -1,4 +1,11 @@
2010-12-30 Nicola Pero <nicola.pero@meta-innovation.com>
+
+ * objc.dg/method-conflict-3.m: New.
+ * objc.dg/method-conflict-4.m: New.
+ * obj-c++.dg/method-conflict-3.m: New.
+ * obj-c++.dg/method-conflict-4.mm: New.
+
+2010-12-30 Nicola Pero <nicola.pero@meta-innovation.com>
* objc.dg/class-extension-3.m: Updated.
* objc.dg/method-1.m: Updated.
Index: testsuite/objc.dg/method-conflict-3.m
===================================================================
--- testsuite/objc.dg/method-conflict-3.m (revision 0)
+++ testsuite/objc.dg/method-conflict-3.m (revision 0)
@@ -0,0 +1,63 @@
+/* Contributed by Nicola Pero <nicola.pero@meta-innovation.com>,
December 2010. */
+/* { dg-do compile } */
+
+#include <objc/objc.h>
+
+/* Test that the compiler can correctly compare protocols in types of
+ method signatures. */
+
+@protocol A, B, C;
+
+@interface MyClass
+- (void) method1: (id)x;
+- (void) method1: (id)x; /* Ok */
+
+- (void) method2: (id <A>)x;
+- (void) method2: (id <A>)x; /* Ok */
+
+- (void) method3: (id <A, B>)x;
+- (void) method3: (id <A, B>)x; /* Ok */
+
+- (void) method4: (id <A, B>)x;
+- (void) method4: (id <A, B, B>)x; /* Ok */
+
+- (void) method5: (id <A, A, B>)x;
+- (void) method5: (id <A, B, B>)x; /* Ok */
+
+- (void) method6: (id <A, A, B, B, C, C>)x;
+- (void) method6: (id <C, A, B>)x; /* Ok */
+
+- (void) method7: (id)x; /* { dg-message "previous declaration" } */
+- (void) method7: (id <A>)x; /* { dg-error "duplicate declaration" } */
+
+- (void) method8: (id <A>)x; /* { dg-message "previous declaration" }
*/
+- (void) method8: (id)x; /* { dg-error "duplicate declaration" } */
+
+- (void) method9: (id <A>)x; /* { dg-message "previous declaration" }
*/
+- (void) method9: (id <B>)x; /* { dg-error "duplicate declaration" } */
+
+- (void) methodA: (id <A>)x; /* { dg-message "previous declaration" }
*/
+- (void) methodA: (id <A, B>)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) methodB: (id <A, B>)x; /* { dg-message "previous
declaration" } */
+- (void) methodB: (id <A>)x; /* { dg-error "duplicate declaration" } */
+
+- (void) methodC: (id <A, B, C>)x; /* { dg-message "previous
declaration" } */
+- (void) methodC: (id <A, B>)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) methodD: (id <A, B, C>)x; /* { dg-message "previous
declaration" } */
+- (void) methodD: (id <A, B, A>)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) methodE: (MyClass <A, B, C> *)x; /* { dg-message "previous
declaration" } */
+- (void) methodE: (MyClass <A, B, A> *)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) methodF: (MyClass <A, B, A> *)x;
+- (void) methodF: (MyClass <A, B, A> *)x; /* Ok */
+
+- (void) methodG: (MyClass *)x; /* { dg-message "previous
declaration" } */
+- (void) methodG: (MyClass <A, B, C> *)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) methodH: (MyClass <A, C>*)x; /* { dg-message "previous
declaration" } */
+- (void) methodH: (MyClass *)x; /* { dg-error "duplicate
declaration" } */
+
+@end
Index: testsuite/objc.dg/method-conflict-4.m
===================================================================
--- testsuite/objc.dg/method-conflict-4.m (revision 0)
+++ testsuite/objc.dg/method-conflict-4.m (revision 0)
@@ -0,0 +1,47 @@
+/* Contributed by Nicola Pero <nicola.pero@meta-innovation.com>,
December 2010. */
+/* { dg-do compile } */
+
+#include <objc/objc.h>
+
+/* Test that the compiler can correctly compare protocols in types of
+ method signatures. In this test we look at protocols implementing
+ other protocols. The fact that one protocol implements another one
+ doesn't mean that they are identical. */
+
+@protocol A
+- (void) doSomething;
+@end
+
+@protocol B <A>
+- (void) doSomethingElse;
+@end
+
+@protocol C <A>
+- (void) doYetSomethingElse;
+@end
+
+@interface MyClass2
+- (void) aMethod: (id <A>)x; /* { dg-message "previous
declaration" } */
+- (void) aMethod: (id <B>)x; /* { dg-error "duplicate declaration" }
*/
+
+- (void) bMethod: (id <B>)x; /* { dg-message "previous
declaration" } */
+- (void) bMethod: (id <A>)x; /* { dg-error "duplicate declaration" }
*/
+
+- (void) cMethod: (id <A, B>)x;
+- (void) cMethod: (id <B>)x; /* Ok - because if you implement B,
then you also implement A, so <B> == <A, B> */
+
+- (void) dMethod: (id <A, B>)x;
+- (void) dMethod: (id <B, A>)x; /* Ok */
+
+- (void) eMethod: (id <A>)x; /* { dg-message "previous
declaration" } */
+- (void) eMethod: (id <B, C>)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) fMethod: (id <B, C>)x; /* { dg-message "previous
declaration" } */
+- (void) fMethod: (id <A>)x; /* { dg-error "duplicate declaration" }
*/
+
+- (void) gMethod: (id <A>)x; /* { dg-message "previous
declaration" } */
+- (void) gMethod: (id <A, B, C>)x; /* { dg-error "duplicate
declaration" } */
+
+- (void) hMethod: (id <A, B, C>)x; /* { dg-message "previous
declaration" } */
+- (void) hMethod: (id <A>)x; /* { dg-error "duplicate declaration" }
*/
+@end
Index: testsuite/obj-c++.dg/method-conflict-3.mm
===================================================================
--- testsuite/obj-c++.dg/method-conflict-3.mm (revision 0)
+++ testsuite/obj-c++.dg/method-conflict-3.mm (revision 0)
@@ -0,0 +1,65 @@
+/* Contributed by Nicola Pero <nicola.pero@meta-innovation.com>,
December 2010. */
+/* { dg-do compile } */
+
+#include <objc/objc.h>
+
+/* Test that the compiler can correctly compare protocols in types of
+ method signatures. */
+
+@protocol A, B, C;
+
+@interface MyClass
+- (void) method1: (id)x;
+- (void) method1: (id)x; /* Ok */
+
+- (void) method2: (id <A>)x;
+- (void) method2: (id <A>)x; /* Ok */
+
+- (void) method3: (id <A, B>)x;
+- (void) method3: (id <A, B>)x; /* Ok */
+
+- (void) method4: (id <A, B>)x;
+- (void) method4: (id <A, B, B>)x; /* Ok */
+
+- (void) method5: (id <A, A, B>)x;
+- (void) method5: (id <A, B, B>)x; /* Ok */
+
+- (void) method6: (id <A, A, B, B, C, C>)x;
+- (void) method6: (id <C, A, B>)x; /* Ok */
+
+- (void) method7: (id)x; /* { dg-warning "previous declaration" } */
+- (void) method7: (id <A>)x; /* { dg-error "duplicate declaration" } */
+
+- (void) method8: (id <A>)x; /* { dg-warning "previous declaration" }
*/
+- (void) method8: (id)x; /* { dg-error "duplicate declaration" } */
+
+- (void) method9: (id <A>)x; /* { dg-warning "previous declaration" }
*/
+- (void) method9: (id <B>)x; /* { dg-error "duplicate declaration" } */
+
+- (void) methodA: (id <A>)x; /* { dg-warning "previous declaration" }
*/
+- (void) methodA: (id <A, B>)x; /* { dg-error "duplicate
declaration" } */
+
+/* FIXME: Bug in the testsuite - the following are done Ok by the
compiler, but
+ the testsuite barfs so we have to comment out the tests. */
+/* - (void) methodB: (id <A, B>)x; dg-warning "previous declaration" */
+/* - (void) methodB: (id <A>)x; dg-error "duplicate declaration" */
+
+/* - (void) methodC: (id <A, B, C>)x; dg-warning "previous
declaration" */
+/* - (void) methodC: (id <A, B>)x; dg-error "duplicate declaration"
*/
+
+/* - (void) methodD: (id <A, B, C>)x; dg-warning "previous
declaration" */
+/* - (void) methodD: (id <A, B, A>)x; dg-error "duplicate
declaration" */
+
+/* - (void) methodE: (MyClass <A, B, C> *)x; dg-warning "previous
declaration" */
+/* - (void) methodE: (MyClass <A, B, A> *)x; dg-error "duplicate
declaration" */
+
+- (void) methodF: (MyClass <A, B, A> *)x;
+- (void) methodF: (MyClass <A, B, A> *)x; /* Ok */
+
+/* - (void) methodG: (MyClass *)x; dg-warning "previous
declaration" */
+/* - (void) methodG: (MyClass <A, B, C> *)x; dg-error "duplicate
declaration" */
+
+/* - (void) methodH: (MyClass <A, C>*)x; dg-warning "previous
declaration" */
+/* - (void) methodH: (MyClass *)x; dg-error "duplicate declaration"
*/
+
+@end
Index: testsuite/obj-c++.dg/method-conflict-4.mm
===================================================================
--- testsuite/obj-c++.dg/method-conflict-4.mm (revision 0)
+++ testsuite/obj-c++.dg/method-conflict-4.mm (revision 0)
@@ -0,0 +1,47 @@
+/* Contributed by Nicola Pero <nicola.pero@meta-innovation.com>,
December 2010. */
+/* { dg-do compile } */
+
+#include <objc/objc.h>
+
+/* Test that the compiler can correctly compare protocols in types of
+ method signatures. In this test we look at protocols implementing
+ other protocols. The fact that one protocol implements another one
+ doesn't mean that they are identical. */
+
+@protocol A
+- (void) doSomething;
+@end
+
+@protocol B <A>
+- (void) doSomethingElse;
+@end
+
+@protocol C <A>
+- (void) doYetSomethingElse;
+@end
+
+@interface MyClass2
+- (void) aMethod: (id <A>)x; /* { dg-error "previous declaration" } */
+- (void) aMethod: (id <B>)x; /* { dg-error "duplicate declaration" }
*/
+
+- (void) bMethod: (id <B>)x; /* { dg-error "previous declaration" } */
+- (void) bMethod: (id <A>)x; /* { dg-error "duplicate declaration" }
*/
+
+- (void) cMethod: (id <A, B>)x;
+- (void) cMethod: (id <B>)x; /* Ok - because if you implement B,
then you also implement A, so <B> == <A, B> */
+
+- (void) dMethod: (id <A, B>)x;
+- (void) dMethod: (id <B, A>)x; /* Ok */
+
+/* FIXME: The compiler works, but the testsuite produces errors
anyway. */
+/* - (void) eMethod: (id <A>)x; dg-error "previous declaration" */
+/* - (void) eMethod: (id <B, C>)x; dg-error "duplicate
declaration" */
+
+/*- (void) fMethod: (id <B, C>)x; dg-error "previous declaration" */
+/*- (void) fMethod: (id <A>)x; dg-error "duplicate declaration" */
+
+/* - (void) gMethod: (id <A>)x; dg-error "previous declaration" */
+/* - (void) gMethod: (id <A, B, C>)x; dg-error "duplicate
declaration" */
+
+/* - (void) hMethod: (id <A, B, C>)x; dg-error "previous
declaration" */
+/* - (void) hMethod: (id <A>)x; dg-error "duplicate declaration" */
+@end