Re: Porting to 64Bit -descriptionForInstanceMethod:

[Andreas Höschler]

Hi David,

On 18 Jun 2019, at 16:22, David Chisnall <gnustep@theravensnest.org> wrote:

- descriptionForInstanceMethod: is gone.  Don't use it, use the runtime functions instead.

Thanks for the hint. 

Where would I find a list (the declaration) of these runtime functions on MacOSX and GNUstep? Are they even identically named? I guess no!?

Here is the top hit for a DDG search for ‘Objective-C Runtime’:

https://developer.apple.com/documentation/objectivec/objective-c_runtime?language=objc

It provides you with the Objective-C Runtime API Reference.  The GNUstep runtime also implements this interface and is source compatible

That’s great! 

(it also implements some non-portable functions, which I would suggest that you avoid).  You can find these all in objc/runtime.h.  

The method that you are probably looking for is protocol_getMethodDescription.

I wonder why I haven’t found that. Thanks!

         struct objc_method_description methodDesc = protocol_getMethodDescription(_protocol, aSelector, YES, YES);

         types = methodDesc.types;            

 This works great as long as I build with -m32. But as soon as I switch to 

...

ADDITIONAL_OBJCFLAGS += -m64 -Wno-deprecated-declarations -Wno-deprecated -Wno-format-security

ADDITIONAL_CFLAGS += -m64

ADDITIONAL_LDFLAGS += -m64

…

in GNUmakefile I get

 Compiling file SRProxy.m ...                                                    ~~                                         ^~~~~~~~~~~~~

                                                    %lu                                        (unsigned long)

SRProxy.m:425:54: warning: implicit declaration of function 'protocol_getMethodDescription' is invalid in C99 [-Wimplicit-function-declaration]

         struct objc_method_description methodDesc = protocol_getMethodDescription(_protocol, aSelector, YES, YES);

                                                     ^

SRProxy.m:425:41: error: variable has incomplete type 'struct objc_method_description'

         struct objc_method_description methodDesc = protocol_getMethodDescription(_protocol, aSelector, YES, YES);

                                        ^

SRProxy.m:425:17: note: forward declaration of 'struct objc_method_description'

         struct objc_method_description methodDesc = protocol_getMethodDescription(_protocol, aSelector, YES, YES);

                ^

Any idea why this works for 32bit code only. I am currently trying to build this on MacOSX 10.10. MacOSX 10.12 gave the same error!? :-(

Thanks so much,

 Andreas