This post might be a bit off topic but I'm hoping there's someone here that can help me.
I'm working on implementing support for the Objective-C ABI in the D programing language. I've based my work on the work made by another developer a couple of years ago. Most of the code is already in place and I'm now trying to make sure everything works after the merging the latest changes from the D compiler.
The problem I have is when linking some code that calls an Objective-C method. As far as I understand the object file is supposed to contain a section __message_refs, in the __OBJC segment. This section contains pointers to C strings, which contain the names of the Objective-C selectors (methods). The C strings are stored in the __cstring __TEXT section and segment. As far as I can see the these sections looks to have the correct flags and contents.
The problem is I'm getting an assertion in the linker:
Line 5024, in Objc1ClassReferences<A>::targetCString. I'm pretty sure that the value of "fit->binding" should be "ld::Fixup::bindingByContentBound" but instead it is "ld::Fixup::bindingDirectlyBound". The definition of these enums are located here:
Line 358, in Fixup::TargetBinding.
This is the result of "dumpobj", a tool shipped with the D compiler, on the D object file that fails to link:
This is the dump of a corresponding Objective-C object file:
The following is a dump using a pre compiled alpha release of the D compiler that the developer I'm basing my work on released in 2011. This does not have this problem:
I'm running Mac OS X 10.8.3. All code is compiled as 32bit.