Subclass overriding methods that return/take NSRange not correctly generated

[brianquinlan]

When generating code for NSMutableIndexSet, this code is produced:

final class _NSRange extends ffi.Struct {
  @NSUInteger()
  external int location;

  @NSUInteger()
  external int length;
}

typedef NSRange = _NSRange;

class NSMutableIndexSet extends objc.NSIndexSet {
  ...
  @override
  objc.NSIndexSet initWithIndexesInRange_(NSRange range) {
    final _ret =
        _objc_msgSend_16(this.pointer, _sel_initWithIndexesInRange_, range);
    return NSMutableIndexSet.castFromPointer(_ret, retain: true, release: true);
  }
  ...
}

But package:objective_c defines NSIndexSet` like:

class NSIndexSet extends NSObject {
   ...
  NSIndexSet initWithIndexesInRange_(_NSRange range) {
    final _ret =
        _objc_msgSend_118(this.pointer, _sel_initWithIndexesInRange_, range);
    return NSIndexSet.castFromPointer(_ret, retain: true, release: true);
  }
  ...

Since the NSRange used in the base and subclass don't match, the @override is not valid. Probably NSRange has to be part of package:objective_c and generated code must reference that.

[brianquinlan]

Maybe NSMutableIndexSet should be part of package:objective_c.

[brianquinlan]

Name issue for NSSimpleCString for these methods:

• initWithCharactersNoCopy_length_deallocator_ (because of deallocator)
• initWithFormat_arguments_ (because of va_list)
• initWithFormat_locale_arguments_ (because of va_list)
• initWithValidatedFormat_validFormatSpecifiers_arguments_error_ (because of va_list)
• initWithValidatedFormat_validFormatSpecifiers_locale_arguments_error_ (becase of va_list)
• initWithBytesNoCopy_length_encoding_deallocator_ (because of deallocator)

[brianquinlan]

I think that you fixed this.

[liamappelbe]

Not sure if it's fixed, but package:objective_c should probably export the NSRange struct, and any other structs it defines.

[brianquinlan]

Doesn't package:objective_c have to export every type that appears anywhere in any API that it exports?

[liamappelbe]

Yep. I've exported all the interfaces, but not the structs.

[brianquinlan]

If you wanted to add a test that verifies that you have exported everything that you need to, you could use dart:mirrors.

[brianquinlan]

Ah, that would explain why the generated buildings are still incorrect:

  @override
  NSMutableIndexSet initWithIndexesInRange_(NSRange range) {

'NSMutableIndexSet.initWithIndexesInRange_' ('NSMutableIndexSet Function(_NSRange)') isn't a valid override of 'NSIndexSet.initWithIndexesInRange_' ('NSIndexSet Function(_NSRange)').

[liamappelbe]

Fixed this a while ago (#1175) but forgot to close it.

[BestOwl]

I can still reproduce this issue when generating code for SFTranscriptionSegment using the ffigen package version 14.0.1 and objective_c version 2.0.0.

[liamappelbe]

@BestOwl can you give me some more information? What buggy behavior are you seeing?

[BestOwl]

Use the following config to generate a bindings for SFTranscriptionSegment

ffigen:
  name: Speech
  description: Bindings for Apple Speech framework
  language: objc
  output: "lib/src/apple_speech_bindings_generated.dart"
  headers:
    entry-points:
      - "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks/Speech.framework/Headers/Speech.h"
  exclude-all-by-default: true
  objc-interfaces:
    include:
      - SFTranscriptionSegment

ffigen produces the warning:

[WARNING]: Generated declaration '_NSRange' starts with '_' and therefore will be private.

and the generated code:

final class _NSRange extends ffi.Struct {
  @ffi.UnsignedLong()
  external int location;

  @ffi.UnsignedLong()
  external int length;
}

...

/// SFTranscriptionSegment
class SFTranscriptionSegment extends objc.NSObject {

...

  /// substringRange
  void getSubstringRange(ffi.Pointer<_NSRange> stret) {
    objc.useMsgSendVariants
        ? _objc_msgSend_437Stret(stret, this.ref.pointer, _sel_substringRange)
        : stret.ref = _objc_msgSend_437(this.ref.pointer, _sel_substringRange);
  }

...

}

The generated code should use NSRange from package:objective_c instead

[liamappelbe]

Oh ok. The bug is probably that _NSRange doesn't match package:objective_c's NSRange. I just need to have it take into account the renaming.