Commit Graph

403 Commits

Author SHA1 Message Date
Puyan Lotfi 9721fbf85b [NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec.
This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.

2nd Landing Attempt...

Differential Revision: https://reviews.llvm.org/D77233
2020-04-23 17:21:25 -04:00
Puyan Lotfi bbf386f02b Revert "[NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec."
This reverts commit 2aa044ed08.

Reverting due to bot failure in lldb.
2020-04-23 00:05:08 -04:00
Puyan Lotfi 2aa044ed08 [NFC] Refactoring PropertyAttributeKind for ObjCPropertyDecl and ObjCDeclSpec.
This is a code clean up of the PropertyAttributeKind and
ObjCPropertyAttributeKind enums in ObjCPropertyDecl and ObjCDeclSpec that are
exactly identical. This non-functional change consolidates these enums
into one. The changes are to many files across clang (and comments in LLVM) so
that everything refers to the new consolidated enum in DeclObjCCommon.h.

Differential Revision: https://reviews.llvm.org/D77233
2020-04-22 23:27:06 -04:00
Simon Pilgrim 69993350ae ObjCMethodDecl::findPropertyDecl - fix static analyzer null dereference warnings. NFCI.
All paths dereference the ClassDecl pointer, so use a cast<> instead of dyn_cast<>, assert that its not null and remove the remaining null tests.
2020-03-12 15:36:49 +00:00
Pierre Habouzit 42f9d0c0be [objc_direct] Tigthen checks for direct methods
Because the name of a direct method must be agreed upon by the caller
and the implementation, certain bad practices that one can get away with
when using dynamism are fatal with direct methods.

To avoid really weird and unscruttable linker error, tighten the
front-end error reporting.

Rule 1:
  Direct methods can only have at most one declaration in an @interface
  container. Any redeclaration is strictly forbidden.

  Today some amount of redeclaration is tolerated between the main
  interface and categories for dynamic methods, but we can't have that.

Rule 2:
  Direct method implementations can only be declared in a matching
  @interface container: when implemented in the primary @implementation
  then the declaration must be in the primary @interface or an
  extension, and when implemented in a category, the declaration must be
  in the @interface for the same category.

Also fix another issue with ObjCMethod::getCanonicalDecl(): when an
implementation lives in the primary @interface, then its canonical
declaration can be in any extension, even when it's not an accessor.

Add Sema tests to cover the new errors, and CG tests to beef up testing
around function names for categories and extensions.

Radar-Id: <rdar://problem/58054563>

Differential Revision: https://reviews.llvm.org/D71694
2019-12-20 10:57:36 -08:00
Pierre Habouzit a4e1819c16 [objc_direct] fix uniquing when re-declaring a readwrite-direct property
ObjCMethodDecl::getCanonicalDecl() for re-declared readwrite properties,
only looks in the ObjCInterface for the declaration of the setter
method, which it won't find.

When the method is a property accessor, we must look in extensions for a
possible redeclaration.

Radar-Id: rdar://problem/57991337

Differential Revision: https://reviews.llvm.org/D71588
2019-12-17 11:07:48 -08:00
Pierre Habouzit d4e1ba3fa9 Implement __attribute__((objc_direct)), __attribute__((objc_direct_members))
__attribute__((objc_direct)) is an attribute on methods declaration, and
__attribute__((objc_direct_members)) on implementation, categories or
extensions.

A `direct` property specifier is added (@property(direct) type name)

These attributes / specifiers cause the method to have no associated
Objective-C metadata (for the property or the method itself), and the
calling convention to be a direct C function call.

The symbol for the method has enforced hidden visibility and such direct
calls are hence unreachable cross image. An explicit C function must be
made if so desired to wrap them.

The implicit `self` and `_cmd` arguments are preserved, however to
maintain compatibility with the usual `objc_msgSend` semantics,
3 fundamental precautions are taken:

1) for instance methods, `self` is nil-checked. On arm64 backends this
   typically adds a single instruction (cbz x0, <closest-ret>) to the
   codegen, for the vast majority of the cases when the return type is a
   scalar.

2) for class methods, because the class may not be realized/initialized
   yet, a call to `[self self]` is emitted. When the proper deployment
   target is used, this is optimized to `objc_opt_self(self)`.

   However, long term we might want to emit something better that the
   optimizer can reason about. When inlining kicks in, these calls
   aren't optimized away as the optimizer has no idea that a single call
   is really necessary.

3) the calling convention for the `_cmd` argument is changed: the caller
   leaves the second argument to the call undefined, and the selector is
   loaded inside the body when it's referenced only.

As far as error reporting goes, the compiler refuses:
- making any overloads direct,
- making an overload of a direct method,
- implementations marked as direct when the declaration in the
  interface isn't (the other way around is allowed, as the direct
  attribute is inherited from the declaration),
- marking methods required for protocol conformance as direct,
- messaging an unqualified `id` with a direct method,
- forming any @selector() expression with only direct selectors.

As warnings:
- any inconsistency of direct-related calling convention when
  @selector() or messaging is used,
- forming any @selector() expression with a possibly direct selector.

Lastly an `objc_direct_members` attribute is added that can decorate
`@implementation` blocks and causes methods only declared there (and in
no `@interface`) to be automatically direct. When decorating an
`@interface` then all methods and properties declared in this block are
marked direct.

Radar-ID: rdar://problem/2684889
Differential Revision: https://reviews.llvm.org/D69991
Reviewed-By: John McCall
2019-11-18 11:48:40 -08:00
Adrian Prantl 2073dd2da7 Redeclare Objective-C property accessors inside the ObjCImplDecl in which they are synthesized.
This patch is motivated by (and factored out from)
https://reviews.llvm.org/D66121 which is a debug info bugfix. Starting
with DWARF 5 all Objective-C methods are nested inside their
containing type, and that patch implements this for synthesized
Objective-C properties.

1. SemaObjCProperty populates a list of synthesized accessors that may
   need to inserted into an ObjCImplDecl.

2. SemaDeclObjC::ActOnEnd inserts forward-declarations for all
   accessors for which no override was provided into their
   ObjCImplDecl. This patch does *not* synthesize AST function
   *bodies*. Moving that code from the static analyzer into Sema may
   be a good idea though.

3. Places that expect all methods to have bodies have been updated.

I did not update the static analyzer's inliner for synthesized
properties to point back to the property declaration (see
test/Analysis/Inputs/expected-plists/nullability-notes.m.plist), which
I believed to be more bug than a feature.

Differential Revision: https://reviews.llvm.org/D68108

rdar://problem/53782400
2019-11-08 08:23:22 -08:00
Fangrui Song 899d13926d Use llvm::stable_sort
llvm-svn: 359098
2019-04-24 14:43:05 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Erik Pilkington 4257857bf8 [Sema][ObjC] Infer availability of +new from availability of -init.
When defined in NSObject, +new will call -init. If -init has been marked
unavailable, diagnose uses of +new.

rdar://18335828

Differential revision: https://reviews.llvm.org/D51189

llvm-svn: 341874
2018-09-10 22:20:09 +00:00
Stephen Kelly 1c301dcbc4 Port getLocEnd -> getEndLoc
Reviewers: teemperor!

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D50351

llvm-svn: 339386
2018-08-09 21:09:38 +00:00
Stephen Kelly f2ceec4811 Port getLocStart -> getBeginLoc
Reviewers: teemperor!

Subscribers: jholewinski, whisperity, jfb, cfe-commits

Differential Revision: https://reviews.llvm.org/D50350

llvm-svn: 339385
2018-08-09 21:08:08 +00:00
Stephen Kelly 02a67baf1e Add getEndLoc API to replace getLocEnd
Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D50348

llvm-svn: 339374
2018-08-09 20:05:47 +00:00
Vlad Tsyrklevich 54d251b901 [AST] Remove the static_assert check in ObjCMethodDecl::ObjCMethodDecl
Summary:
This check was introduced by r338641
but this broke some builds. For now remove it.

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D50163

llvm-svn: 338648
2018-08-01 22:41:03 +00:00
Erich Keane 9b18eca352 [AST][4/4] Move the bit-fields from ObjCMethodDecl and ObjCContainerDecl into DeclContext
This patch follows https://reviews.llvm.org/D49729,
https://reviews.llvm.org/D49732 and
https://reviews.llvm.org/D49733.

Move the bits from ObjCMethodDecl and ObjCContainerDecl
into DeclContext.

Differential Revision: https://reviews.llvm.org/D49734

Patch By: bricci

llvm-svn: 338641
2018-08-01 21:31:08 +00:00
Fangrui Song 6907ce2f8f Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338291
2018-07-30 19:24:48 +00:00
Adrian Prantl 9fc8faf9e6 Remove \brief commands from doxygen comments.
This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
2018-05-09 01:00:01 +00:00
Eugene Zelenko 2a1ba94f24 [AST] Fix some Clang-tidy modernize-use-auto warnings; other minor fixes (NFC).
llvm-svn: 329630
2018-04-09 22:14:10 +00:00
Alexander Kornienko 2a8c18d991 Fix typos in clang
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:

  archtype
  cas
  classs
  checkk
  compres
  definit
  frome
  iff
  inteval
  ith
  lod
  methode
  nd
  optin
  ot
  pres
  statics
  te
  thru

Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)

Differential revision: https://reviews.llvm.org/D44188

llvm-svn: 329399
2018-04-06 15:14:32 +00:00
Eugene Zelenko 2f8e66bbd8 [AST] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 318882
2017-11-22 21:32:07 +00:00
Alex Lorenz 50b2dd336e [ObjC] Pick a 'readwrite' property when synthesizing ambiguous
property and check for incompatible attributes

This commit changes the way ambiguous property synthesis (i.e. when synthesizing
a property that's declared in multiple protocols) is performed. Previously,
Clang synthesized the first property that was found. This lead to problems when
the property was synthesized in a class that conformed to two protocols that
declared that property and a second protocols had a 'readwrite' declaration -
the setter was not synthesized so the class didn't really conform to the second
protocol and user's code would crash at runtime when they would try to set the
property.

This commit ensures that a first readwrite property is selected. This is a
semantic change that changes users code in this manner:

```
@protocol P @property(readonly) int p; @end
@protocol P2 @property(readwrite) id p; @end
@interface I <P2> @end
@implementation I
@syntesize p; // Users previously got a warning here, and Clang synthesized
              // readonly 'int p' here. Now Clang synthesizes readwrite 'id' p..
@end
```

To ensure that this change is safe, the warning about incompatible types is
promoted to an error when this kind of readonly/readwrite ambiguity is detected
in the @implementation. This will ensure that previous code that had this subtle
bug and ignored the warning now will fail to compile with an error, and users
should not get suprises at runtime once they resolve the error.

The commit also extends the ambiguity checker, and now it can detect conflicts
among the different property attributes. An error diagnostic is used for
conflicting attributes, to ensure that the user won't get "suprises" at runtime.

ProtocolPropertyMap is removed in favour of a a set + vector because the map's
order of iteration is non-deterministic, so it couldn't be used to select the
readwrite property.

rdar://31579994

Differential Revision: https://reviews.llvm.org/D35268

llvm-svn: 307903
2017-07-13 11:06:22 +00:00
Alexey Bataev 56223237b0 [DebugInfo] Add kind of ImplicitParamDecl for emission of FlagObjectPointer.
Summary:
If the first parameter of the function is the ImplicitParamDecl, codegen
automatically marks it as an implicit argument with `this` or `self`
pointer. Added internal kind of the ImplicitParamDecl to separate
'this', 'self', 'vtt' and other implicit parameters from other kind of
parameters.

Reviewers: rjmccall, aaron.ballman

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33735

llvm-svn: 305075
2017-06-09 13:40:18 +00:00
Bruno Cardoso Lopes faaeae5d6e [Modules][ObjC] Check definition from canonical decl on designated initializers
Use definition from canonical decl when checking for designated
initializers. This is necessary since deserialization of a interface
might reuse the definition from the canonical one (see r281119).

rdar://problem/29360655

llvm-svn: 301382
2017-04-26 05:06:20 +00:00
Alex Lorenz 5ffe4e14f1 [ObjC][ARC] Avoid -Warc-performSelector-leaks for performSelector variations
that became supported after r297019

The commit r297019 expanded the performSelector ObjC method family heuristic
to ensure that -Wobjc-unsafe-perform-selector covers all performSelector
variations. However, this made the -Warc-performSelector-leaks too noisy, as
that warning produces mostly false positives since the selector is unknown.
This commit reverts the ObjC method family heuristics introduced in r297019.
This ensures that -Warc-performSelector-leaks isn't too noisy. The commit still
preserves the coverage of -Wobjc-unsafe-perform-selector.

rdar://31124629

llvm-svn: 298587
2017-03-23 10:46:05 +00:00
Alex Lorenz 0e23c61c87 [Sema][ObjC] Warn about 'performSelector' calls with selectors
that return record or vector types

The performSelector family of methods from Foundation use objc_msgSend to
dispatch the selector invocations to objects. However, method calls to methods
that return record types might have to use the objc_msgSend_stret as the return
value won't find into the register. This is also supported by this sentence from
performSelector documentation: "The method should not have a significant return
value and should take a single argument of type id, or no arguments". This
commit adds a new warning that warns when a selector which corresponds to a
method that returns a record type is passed into performSelector.

rdar://12056271

Differential Revision: https://reviews.llvm.org/D30174

llvm-svn: 297019
2017-03-06 15:58:34 +00:00
Alex Lorenz f9a28a287c [ObjC][Modules] Don't perform property lookup in hidden class extensions
rdar://30603803

llvm-svn: 295903
2017-02-22 23:18:49 +00:00
Alex Lorenz ff6c34b30d [ObjC] Prevent infinite loops when iterating over redeclaration
of a method that was declared in an invalid interface

This commit fixes an infinite loop that occurs when clang tries to iterate over
redeclaration of a method that was declared in an invalid @interface. The
existing validity checks don't catch this as that @interface is a duplicate of
a previously declared valid @interface declaration, so we have to verify that
the found redeclaration is in a valid declaration context.

rdar://29220965

Differential Revision: https://reviews.llvm.org/D26664

llvm-svn: 287530
2016-11-21 11:16:30 +00:00
Benjamin Kramer c3f89253ae Retire llvm::alignOf in favor of C++11 alignof.
No functionality change intended.

llvm-svn: 284730
2016-10-20 14:27:22 +00:00
Manman Ren a0042c4922 ObjectiveC: fix a seg fault when deserialing redeclaration of ObjCMethodDecl.
The deserialization of redeclartion can cause seg fault since getCanonicalDecl
of the redeclaration returns the lookup result on the ObjCContainerDecl,
which can be null if FindExternalVisibleDeclsByName is not done updating
the lookup results.

The fix is to return the redeclaration itself as the canonical decl. Note that
the handling for redeclaration of ObjCMethodDecl is not in line with other
redeclarables.

rdar://28488466

llvm-svn: 283145
2016-10-03 21:26:46 +00:00
Manman Ren c5705bae05 ObjectiveC Generics: Start using ObjCTypeParamType.
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
2016-09-13 17:41:05 +00:00
Jordan Rose 31cf7d49db Fix ObjCMethodDecl::findPropertyDecl for class properties.
This affects code completion and a few other things; hopefully the code completion
test is sufficient to catch regressions.

llvm-svn: 263295
2016-03-11 21:14:40 +00:00
Manman Ren 494ee5b049 Class Property: change PropertyMap to include isClassProperty.
PropertyMap used to map IdentifierInfo (name of the property) to
ObjcPropertyDecl *. Now that a class property can have the same name as
an instance property, we change PropertyMap to map a pair <IdentifierInfo *,
unsigned> to ObjcPropertyDecl *.

Also update a few places from iterating over instance_properties to
iterating over all properties.

rdar://23891898

llvm-svn: 259119
2016-01-28 23:36:05 +00:00
Manman Ren 5b786407d0 Class Property: class property and instance property can have the same name.
Add "enum ObjCPropertyQueryKind" to a few APIs that used to only take the name
of the property: ObjCPropertyDecl::findPropertyDecl,
ObjCContainerDecl::FindPropertyDeclaration,
ObjCInterfaceDecl::FindPropertyVisibleInPrimaryClass,
ObjCImplDecl::FindPropertyImplDecl, and Sema::ActOnPropertyImplDecl.

ObjCPropertyQueryKind currently has 3 values:
OBJC_PR_query_unknown, OBJC_PR_query_instance, OBJC_PR_query_class

This extra parameter specifies that we are looking for an instance property with
the given name, or a class property with the given name, or any property with
the given name (if both exist, the instance property will be returned).

rdar://23891898

llvm-svn: 259070
2016-01-28 18:49:28 +00:00
Manman Ren efe1bacd92 Class Property: handle class properties.
At places where we handle instance properties, if necessary.

rdar://23891898

llvm-svn: 258979
2016-01-27 20:00:32 +00:00
Manman Ren a7a8b1f2c0 Use instance_properties instead of properties. NFC.
All current properties are instance properties.

This is the second patch in a series of patches to support class properties
in addition to instance properties in objective-c.

rdar://23891898

llvm-svn: 258824
2016-01-26 18:05:23 +00:00
James Y Knight 967eb20ebe [TrailingObjects] Convert Decl* classes.
Also remove now-redundant explicit alignment specification on some of
the classes converted prior to TrailingObjects automatically ensuring
proper alignment.

llvm-svn: 256585
2015-12-29 22:13:13 +00:00
Douglas Gregor acf4fd3039 Stop back-patching 'readonly' Objective-C properties with 'readwrite' ones.
A 'readonly' Objective-C property declared in the primary class can
effectively be shadowed by a 'readwrite' property declared within an
extension of that class, so long as the types and attributes of the
two property declarations are compatible.

Previously, this functionality was implemented by back-patching the
original 'readonly' property to make it 'readwrite', destroying source
information and causing some hideously redundant, incorrect
code. Simplify the implementation to express how this should actually
be modeled: as a separate property declaration in the extension that
shadows (via the name lookup rules) the declaration in the primary
class. While here, correct some broken Fix-Its, eliminate a pile of
redundant code, clean up the ARC migrator's handling of properties
declared in extensions, and fix debug info's naming of methods that
come from categories.

A wonderous side effect of doing this write is that it eliminates the
"AddedObjCPropertyInClassExtension" method from the AST mutation
listener, which in turn eliminates the last place where we rewrite
entire declarations in a chained PCH file or a module file. This
change (which fixes rdar://problem/18475765) will allow us to
eliminate the rewritten-decls logic from the serialization library,
and fixes a crash (rdar://problem/23247794) illustrated by the
test/PCH/chain-categories.m example.

llvm-svn: 251874
2015-11-03 01:15:46 +00:00
Adrian Prantl 2ecf89ebb3 DeclObjC: Move computing the type of self into a separate function (NFC).
This function will be used for emitting debug info.

llvm-svn: 241748
2015-07-08 22:15:59 +00:00
Aaron Ballman 76413ecb60 Use AlignOf instead of alignOf so that this can go back to being a static_assert. Amends r241577.
llvm-svn: 241604
2015-07-07 17:12:14 +00:00
Aaron Ballman 5bcb832307 Changing a use of alignof() into llvm::alignOf() for MSVC compatibility. This requires changing a static_assert into an assert, too.
llvm-svn: 241577
2015-07-07 12:50:30 +00:00
Douglas Gregor 0a8890ff45 Don't rely on the use of non-POD types within unions.
They aren't universally supported and we're not getting any benefit
from using them.

llvm-svn: 241564
2015-07-07 06:20:46 +00:00
Douglas Gregor 9b7b3e9038 [libclang] Replace ObjC generic parameters when code-completing method implementations.
rdar://20643768

llvm-svn: 241559
2015-07-07 06:20:27 +00:00
Douglas Gregor ab7f0b342f The AST importer had a bug where it would enter into an infinite recursion
when importing type parameter lists.  The reason is that type parameters
have their DeclContexts set to the interface that is parameterized with those
types, and the importer would follow that loop and blow the stack out.

I've changed the way this works so that the type parameters are only imported
after the interface that contains them has been registered via the Imported()
function.

This is tested by LLDB.

<rdar://problem/20315663>

llvm-svn: 241556
2015-07-07 06:20:12 +00:00
Douglas Gregor 1ac1b63c9c Implement variance for Objective-C type parameters.
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
2015-07-07 03:58:54 +00:00
Douglas Gregor c5e07f5c11 Improve the Objective-C common-type computation used by the ternary operator.
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
2015-07-07 03:58:01 +00:00
Douglas Gregor e83b95641f Substitute type arguments into uses of Objective-C interface members.
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
2015-07-07 03:57:53 +00:00
Douglas Gregor e9d95f1ecc Handle Objective-C type arguments.
Objective-C type arguments can be provided in angle brackets following
an Objective-C interface type. Syntactically, this is the same
position as one would provide protocol qualifiers (e.g.,
id<NSCopying>), so parse both together and let Sema sort out the
ambiguous cases. This applies both when parsing types and when parsing
the superclass of an Objective-C class, which can now be a specialized
type (e.g., NSMutableArray<T> inherits from NSArray<T>).

Check Objective-C type arguments against the type parameters of the
corresponding class. Verify the length of the type argument list and
that each type argument satisfies the corresponding bound.

Specializations of parameterized Objective-C classes are represented
in the type system as distinct types. Both specialized types (e.g.,
NSArray<NSString *> *) and unspecialized types (NSArray *) are
represented, separately.

llvm-svn: 241542
2015-07-07 03:57:35 +00:00
Douglas Gregor 85f3f9513d Parsing, semantic analysis, and AST for Objective-C type parameters.
Produce type parameter declarations for Objective-C type parameters,
and attach lists of type parameters to Objective-C classes,
categories, forward declarations, and extensions as
appropriate. Perform semantic analysis of type bounds for type
parameters, both in isolation and across classes/categories/extensions
to ensure consistency.

Also handle (de-)serialization of Objective-C type parameter lists,
along with sundry other things one must do to add a new declaration to
Clang.

Note that Objective-C type parameters are typedef name declarations,
like typedefs and C++11 type aliases, in support of type erasure.

Part of rdar://problem/6294649.

llvm-svn: 241541
2015-07-07 03:57:15 +00:00
Alexander Kornienko ab9db51042 Revert r240270 ("Fixed/added namespace ending comments using clang-tidy").
llvm-svn: 240353
2015-06-22 23:07:51 +00:00