We have a new policy in place making links to private resources
something we try to avoid in source and test files. Normally, we'd
organically switch to the new policy rather than make a sweeping change
across a project. However, Clang is in a somewhat special circumstance
currently: recently, I've had several new contributors run into rdar
links around test code which their patch was changing the behavior of.
This turns out to be a surprisingly bad experience, especially for
newer folks, for a handful of reasons: not understanding what the link
is and feeling intimidated by it, wondering whether their changes are
actually breaking something important to a downstream in some way,
having to hunt down strangers not involved with the patch to impose on
them for help, accidental pressure from asking for potentially private
IP to be made public, etc. Because folks run into these links entirely
by chance (through fixing bugs or working on new features), there's not
really a set of problematic links to focus on -- all of the links have
basically the same potential for causing these problems. As a result,
this is an omnibus patch to remove all such links.
This was not a mechanical change; it was done by manually searching for
rdar, radar, radr, and other variants to find all the various
problematic links. From there, I tried to retain or reword the
surrounding comments so that we would lose as little context as
possible. However, because most links were just a plain link with no
supporting context, the majority of the changes are simple removals.
Differential Review: https://reviews.llvm.org/D158071
When a category/extension doesn't repeat a type bound, corresponding
type parameter is substituted with `id` when used as a type argument. As
a result, in the added test case it was causing errors like
> type argument 'T' (aka 'id') does not satisfy the bound ('id<NSCopying>') of type parameter 'T'
We are already checking that type parameters should be consistent
everywhere (see `checkTypeParamListConsistency`) and update
`ObjCTypeParamDecl` to have correct underlying type. And when we use the
type parameter as a method return type or a method parameter type, it is
substituted to the bounded type. But when we use the type parameter as a
type argument, we check `ObjCTypeParamType` that wasn't updated and
remains `id`.
Fix by updating not only `ObjCTypeParamDecl` UnderlyingType but also
TypeForDecl as we use the underlying type to create a canonical type for
`ObjCTypeParamType` (see `ASTContext::getObjCTypeParamType`).
This is a different approach to fixing the issue. The previous one was
02c2ab3d8872416589bd1a6ca3dfb96ba373a3b9 which was reverted in
4c539e8da1b3de38a53ef3f7497f5c45a3243b61. The problem with the previous
approach was that `ObjCTypeParamType::desugar` was returning underlying
type for `ObjCTypeParamDecl` without applying any protocols stored in
`ObjCTypeParamType`. It caused inconsistencies in comparing types before
and after desugaring.
Re-applying after fixing intermittent test failures.
rdar://problem/54329242
Reviewed By: erik.pilkington
Differential Revision: https://reviews.llvm.org/D72872
This reverts commit a8c8b627f23f204fb621bd2a8c495cfc8bc16ae7. It causes
intermittent
Clang :: SemaObjC/parameterized_classes_subst.m
test failures on various bots.
When a category/extension doesn't repeat a type bound, corresponding
type parameter is substituted with `id` when used as a type argument. As
a result, in the added test case it was causing errors like
> type argument 'T' (aka 'id') does not satisfy the bound ('id<NSCopying>') of type parameter 'T'
We are already checking that type parameters should be consistent
everywhere (see `checkTypeParamListConsistency`) and update
`ObjCTypeParamDecl` to have correct underlying type. And when we use the
type parameter as a method return type or a method parameter type, it is
substituted to the bounded type. But when we use the type parameter as a
type argument, we check `ObjCTypeParamType` that wasn't updated and
remains `id`.
Fix by updating not only `ObjCTypeParamDecl` UnderlyingType but also
TypeForDecl as we use the underlying type to create a canonical type for
`ObjCTypeParamType` (see `ASTContext::getObjCTypeParamType`).
This is a different approach to fixing the issue. The previous one was
02c2ab3d8872416589bd1a6ca3dfb96ba373a3b9 which was reverted in
4c539e8da1b3de38a53ef3f7497f5c45a3243b61. The problem with the previous
approach was that `ObjCTypeParamType::desugar` was returning underlying
type for `ObjCTypeParamDecl` without applying any protocols stored in
`ObjCTypeParamType`. It caused inconsistencies in comparing types before
and after desugaring.
rdar://problem/54329242
Reviewed By: erik.pilkington
Differential Revision: https://reviews.llvm.org/D72872
This introduced new errors, see below. Reverting until that can be investigated
properly.
#import <AVFoundation/AVFoundation.h>
void f(int width, int height) {
FourCharCode best_fourcc = kCMPixelFormat_422YpCbCr8_yuvs;
NSDictionary* videoSettingsDictionary = @{
(id)kCVPixelBufferPixelFormatTypeKey : @(best_fourcc),
};
}
$ clang++ -c /tmp/a.mm
/tmp/a.mm:6:5: error: cannot initialize a parameter of type
'KeyType<NSCopying> _Nonnull const' (aka 'const id') with an rvalue
of type 'id'
(id)kCVPixelBufferPixelFormatTypeKey : @(best_fourcc),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
> When a category/extension doesn't repeat a type bound, corresponding
> type parameter is substituted with `id` when used as a type argument. As
> a result, in the added test case it was causing errors like
>
> > type argument 'T' (aka 'id') does not satisfy the bound ('id<NSCopying>') of type parameter 'T'
>
> We are already checking that type parameters should be consistent
> everywhere (see `checkTypeParamListConsistency`) and update
> `ObjCTypeParamDecl` to have correct underlying type. And when we use the
> type parameter as a method return type or a method parameter type, it is
> substituted to the bounded type. But when we use the type parameter as a
> type argument, we check `ObjCTypeParamType` that ignores the updated
> underlying type and remains `id`.
>
> Fix by desugaring `ObjCTypeParamType` to the underlying type, the same
> way we are doing with `TypedefType`.
>
> rdar://problem/54329242
>
> Reviewers: erik.pilkington, ahatanak
>
> Reviewed By: erik.pilkington
>
> Subscribers: jkorous, dexonsmith, ributzka, cfe-commits
>
> Differential Revision: https://reviews.llvm.org/D66696
When a category/extension doesn't repeat a type bound, corresponding
type parameter is substituted with `id` when used as a type argument. As
a result, in the added test case it was causing errors like
> type argument 'T' (aka 'id') does not satisfy the bound ('id<NSCopying>') of type parameter 'T'
We are already checking that type parameters should be consistent
everywhere (see `checkTypeParamListConsistency`) and update
`ObjCTypeParamDecl` to have correct underlying type. And when we use the
type parameter as a method return type or a method parameter type, it is
substituted to the bounded type. But when we use the type parameter as a
type argument, we check `ObjCTypeParamType` that ignores the updated
underlying type and remains `id`.
Fix by desugaring `ObjCTypeParamType` to the underlying type, the same
way we are doing with `TypedefType`.
rdar://problem/54329242
Reviewers: erik.pilkington, ahatanak
Reviewed By: erik.pilkington
Subscribers: jkorous, dexonsmith, ributzka, cfe-commits
Differential Revision: https://reviews.llvm.org/D66696
llvm-svn: 374202
`QualType::substObjCTypeArgs` doesn't go past non-canonical types and as
the result misses some of the substitutions like `ObjCTypeParamType`.
Update `SimpleTransformVisitor` to traverse past the type sugar.
Reviewers: ahatanak, erik.pilkington
Reviewed By: erik.pilkington
Subscribers: jkorous, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D57270
llvm-svn: 354164
For ObjC type parameter, we used to have TypedefType that is canonicalized to
id or the bound type. We can't represent "T <protocol>" and thus will lose
the type information in the following example:
@interface MyMutableDictionary<KeyType, ObjectType> : NSObject
- (void)setObject:(ObjectType)obj forKeyedSubscript:(KeyType <NSCopying>)key;
@end
MyMutableDictionary<NSString *, NSString *> *stringsByString;
NSNumber *n1, *n2;
stringsByString[n1] = n2;
--> no warning on type mismatch of the key.
To fix the problem, we introduce a new type ObjCTypeParamType that supports
a list of protocol qualifiers.
We create ObjCTypeParamType for ObjCTypeParamDecl when we create
ObjCTypeParamDecl. We also substitute ObjCTypeParamType instead of TypedefType
on an ObjCTypeParamDecl.
rdar://24619481
rdar://25060179
Differential Revision: http://reviews.llvm.org/D23080
llvm-svn: 281358
Introduce co- and contra-variance for Objective-C type parameters,
which allows us to express that (for example) an NSArray is covariant
in its type parameter. This means that NSArray<NSMutableString *> * is
a subtype of NSArray<NSString *> *, which is expected of the immutable
Foundation collections.
Type parameters can be annotated with __covariant or __contravariant
to make them co- or contra-variant, respectively. This feature can be
detected by __has_feature(objc_generics_variance). Implements
rdar://problem/20217490.
llvm-svn: 241549
The __kindof type qualifier can be applied to Objective-C object
(pointer) types to indicate id-like behavior, which includes implicit
"downcasting" of __kindof types to subclasses and id-like message-send
behavior. __kindof types provide better type bounds for substitutions
into unspecified generic types, which preserves more type information.
llvm-svn: 241548
Warn in cases where one has provided redundant protocol qualification
that might be a typo for a specialization, e.g., NSArray<NSObject>,
which is pointless (NSArray declares that it conforms to NSObject) and
is likely to be a typo for NSArray<NSObject *>, i.e., an array of
NSObject pointers. This warning is very narrow, only applying when the
base type being qualified is parameterized, has the same number of
parameters as their are protocols listed, all of the names can also
refer to types (including Objective-C class types, of course), and at
least one of those types is an Objective-C class (making this a typo
for a missing '*'). The limitations are partly for performance reasons
(we don't want to do redundant name lookup unless we really need to),
and because we want the warning to apply in very limited cases to
limit false positives.
Part of rdar://problem/6294649.
llvm-svn: 241547
The Objective-C common-type computation had a few problems that
required a significant rework, including:
- Quadradic behavior when finding the common base type; now it's
linear.
- Keeping around type arguments when computing the common type
between a specialized and an unspecialized type
- Introducing redundant protocol qualifiers.
Part of rdar://problem/6294649. Also fixes rdar://problem/19572837 by
addressing a longstanding bug in
ASTContext::CollectInheritedProtocols().
llvm-svn: 241544
When messaging a method that was defined in an Objective-C class (or
category or extension thereof) that has type parameters, substitute
the type arguments for those type parameters. Similarly, substitute
into property accesses, instance variables, and other references.
This includes general infrastructure for substituting the type
arguments associated with an ObjCObject(Pointer)Type into a type
referenced within a particular context, handling all of the
substitutions required to deal with (e.g.) inheritance involving
parameterized classes. In cases where no type arguments are available
(e.g., because we're messaging via some unspecialized type, id, etc.),
we substitute in the type bounds for the type parameters instead.
Example:
@interface NSSet<T : id<NSCopying>> : NSObject <NSCopying>
- (T)firstObject;
@end
void f(NSSet<NSString *> *stringSet, NSSet *anySet) {
[stringSet firstObject]; // produces NSString*
[anySet firstObject]; // produces id<NSCopying> (the bound)
}
When substituting for the type parameters given an unspecialized
context (i.e., no specific type arguments were given), substituting
the type bounds unconditionally produces type signatures that are too
strong compared to the pre-generics signatures. Instead, use the
following rule:
- In covariant positions, such as method return types, replace type
parameters with “id” or “Class” (the latter only when the type
parameter bound is “Class” or qualified class, e.g,
“Class<NSCopying>”)
- In other positions (e.g., parameter types), replace type
parameters with their type bounds.
- When a specialized Objective-C object or object pointer type
contains a type parameter in its type arguments (e.g.,
NSArray<T>*, but not NSArray<NSString *> *), replace the entire
object/object pointer type with its unspecialized version (e.g.,
NSArray *).
llvm-svn: 241543
