static tree
objc_add_method (tree klass, tree method, int is_class, bool is_optional)
{
- tree mth;
+ tree existing_method = NULL_TREE;
- /* @optional methods are added to protocol's OPTIONAL list. Note
- that this disables checking that the methods are implemented by
- classes implementing the protocol, since these checks only use
- the CLASS_CLS_METHODS and CLASS_NST_METHODS. */
- if (is_optional)
+ /* The first thing we do is look up the method in the list of
+ methods already defined in the interface (or implementation). */
+ if (is_class)
+ existing_method = lookup_method (CLASS_CLS_METHODS (klass), method);
+ else
+ existing_method = lookup_method (CLASS_NST_METHODS (klass), method);
+
+ /* In the case of protocols, we have a second list of methods to
+ consider, the list of optional ones. */
+ if (TREE_CODE (klass) == PROTOCOL_INTERFACE_TYPE)
{
- gcc_assert (TREE_CODE (klass) == PROTOCOL_INTERFACE_TYPE);
- if (!(mth = lookup_method (is_class
- ? PROTOCOL_OPTIONAL_CLS_METHODS (klass)
- : PROTOCOL_OPTIONAL_NST_METHODS (klass),
- method)))
+ /* @required methods are added to the protocol's normal list.
+ @optional methods are added to the protocol's OPTIONAL lists.
+ Note that adding the methods to the optional lists disables
+ checking that the methods are implemented by classes
+ implementing the protocol, since these checks only use the
+ CLASS_CLS_METHODS and CLASS_NST_METHODS. */
+
+ /* First of all, if the method to add is @optional, and we found
+ it already existing as @required, emit an error. */
+ if (is_optional && existing_method)
+ {
+ error ("method %<%c%E%> declared %<@optional%> and %<@required%> at the same time",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ inform (DECL_SOURCE_LOCATION (existing_method),
+ "previous declaration of %<%c%E%> as %<@required%>",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ }
+
+ /* Now check the list of @optional methods if we didn't find the
+ method in the @required list. */
+ if (!existing_method)
{
if (is_class)
+ existing_method = lookup_method (PROTOCOL_OPTIONAL_CLS_METHODS (klass), method);
+ else
+ existing_method = lookup_method (PROTOCOL_OPTIONAL_NST_METHODS (klass), method);
+
+ if (!is_optional && existing_method)
{
+ error ("method %<%c%E%> declared %<@optional%> and %<@required%> at the same time",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ inform (DECL_SOURCE_LOCATION (existing_method),
+ "previous declaration of %<%c%E%> as %<@optional%>",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ }
+ }
+ }
+
+ /* If the method didn't exist already, add it. */
+ if (!existing_method)
+ {
+ if (is_optional)
+ {
+ if (is_class)
+ {
+ /* Put the method on the list in reverse order. */
TREE_CHAIN (method) = PROTOCOL_OPTIONAL_CLS_METHODS (klass);
PROTOCOL_OPTIONAL_CLS_METHODS (klass) = method;
}
PROTOCOL_OPTIONAL_NST_METHODS (klass) = method;
}
}
- }
- else if (!(mth = lookup_method (is_class
- ? CLASS_CLS_METHODS (klass)
- : CLASS_NST_METHODS (klass), method)))
- {
- /* put method on list in reverse order */
- if (is_class)
- {
- DECL_CHAIN (method) = CLASS_CLS_METHODS (klass);
- CLASS_CLS_METHODS (klass) = method;
- }
else
{
- DECL_CHAIN (method) = CLASS_NST_METHODS (klass);
- CLASS_NST_METHODS (klass) = method;
+ if (is_class)
+ {
+ DECL_CHAIN (method) = CLASS_CLS_METHODS (klass);
+ CLASS_CLS_METHODS (klass) = method;
+ }
+ else
+ {
+ DECL_CHAIN (method) = CLASS_NST_METHODS (klass);
+ CLASS_NST_METHODS (klass) = method;
+ }
}
}
else
{
- /* When processing an @interface for a class or category, give hard
- errors on methods with identical selectors but differing argument
- and/or return types. We do not do this for @implementations, because
- C/C++ will do it for us (i.e., there will be duplicate function
- definition errors). */
+ /* The method was already defined. Check that the types match
+ for an @interface for a class or category, or for a
+ @protocol. Give hard errors on methods with identical
+ selectors but differing argument and/or return types. We do
+ not do this for @implementations, because C/C++ will do it
+ for us (i.e., there will be duplicate function definition
+ errors). */
if ((TREE_CODE (klass) == CLASS_INTERFACE_TYPE
- || TREE_CODE (klass) == CATEGORY_INTERFACE_TYPE)
- && !comp_proto_with_proto (method, mth, 1))
- error ("duplicate declaration of method %<%c%E%>",
- is_class ? '+' : '-',
- METHOD_SEL_NAME (mth));
+ || TREE_CODE (klass) == CATEGORY_INTERFACE_TYPE
+ /* Starting with GCC 4.6, we emit the same error for
+ protocols too. The situation is identical to
+ @interfaces as there is no possible meaningful reason
+ for defining the same method with different signatures
+ in the very same @protocol. If that was allowed,
+ whenever the protocol is used (both at compile and run
+ time) there wouldn't be any meaningful way to decide
+ which of the two method signatures should be used. */
+ || TREE_CODE (klass) == PROTOCOL_INTERFACE_TYPE)
+ && !comp_proto_with_proto (method, existing_method, 1))
+ {
+ error ("duplicate declaration of method %<%c%E%> with conflicting types",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ inform (DECL_SOURCE_LOCATION (existing_method),
+ "previous declaration of %<%c%E%>",
+ (is_class ? '+' : '-'),
+ METHOD_SEL_NAME (existing_method));
+ }
}
if (is_class)
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