[ObjC] Improve the parsing of message type encoding strings #7309
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
bdash
force-pushed
the
objc-method-type-encodings
branch
from
de408e1 to
de0397e
Compare
The compiler represents block parameters as `@?` in the method type encoding string. We had been parsing this as two separate parameters (one `id` and one unknown type that was mapped to `void*`), resulting in some Objective-C method implementations incorrectly having an extra parameter. We cannot represent a Clang block (e.g., `void (^)()`) in the type system at present. Since these are Objective-C compatible types the simplest solution for now is to represent them as `id`.
Incorrect parsing of method type encoding strings was causing incorrect function types to be applied to Objective-C method implementations. In some cases this would result in confusion about which stack locations specific parameters resided at. `q`, `Q` and `d` were being mapped to `NSInteger`, `NSUInteger` and `CGFloat` respectively. While this works for 64-bit platforms, the type aliases refer to 32-bit types on 32-bit platforms. These type encodings are explicitly for 64-bit types. To address this `q`, `Q` and `d` are now mapped to `int64_t`, `uint64_t` and `double` respectively. `l` and `L` were incorrectly being interpreted as `int64_t` and `uint64_t`. While `long` is a 64-bit type on 64-bit Apple platforms, the `l` / `L` type encodings always refer to a 32-bit type. `S` was mistakenly being mapped to `uint8_t`. It is now `uint16_t` as intended.
bdash
force-pushed
the
objc-method-type-encodings
branch
from
de0397e to
8697436
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This does two main things:
Fixes the parsing of
@?which is used to represent a block argument. Since we do not have type system support for blocks and blocks can be treated as Objective-C objects, they are mapped toid.Fixes some incorrect handling of integer and floating point types, particularly on 32-bit platforms.
q,Qanddwere being mapped toNSInteger,NSUIntegerandCGFloatrespectively. While this works for 64-bit platforms, the type aliases refer to 32-bit types on 32-bit platforms. These type encodings are explicitly for 64-bit types. To address thisq,Qanddare now mapped toint64_t,uint64_tanddoublerespectively.landLwere incorrectly being interpreted asint64_tanduint64_t. Whilelongis a 64-bit type on 64-bit Apple platforms, thel/Ltype encodings always refer to a 32-bit type.Swas mistakenly being mapped touint8_t. It is nowuint16_tas intended.