Porting to 64Bit -descriptionForInstanceMethod:

[Andreas Höschler]

Hi all,

this is probably only partially GNUstep related but anyway. I have just started to port my code - which builds fine [using GNUstep make] on current GNUstep and all MacOSX versions I have here - to 64Bit. For that I opened the GNUMakefile and replaced

ADDITIONAL_OBJCFLAGS += -m32 -Wno-deprecated-declarations -Wno-deprecated -Wno-format-security

ADDITIONAL_CFLAGS += -m32

ADDITIONAL_LDFLAGS += -m32

with

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

ADDITIONAL_CFLAGS += -m64

ADDITIONAL_LDFLAGS += -m64

When compiling 

         Protocol *_protocol = …;

         char *types = NULL;

         types = [_protocol descriptionForInstanceMethod:aSelector]->types;  // -m32 delivers objc_method_description*, -m64 delivers objc_object*            

I get 

SRProxy.m:419:29: warning: instance method '-descriptionForInstanceMethod:' not found (return type defaults to 'id') [-Wobjc-method-access]

         types = [_protocol descriptionForInstanceMethod:aSelector]->types;  

                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

/usr/include/objc/Protocol.h:45:12: note: receiver is instance of class declared here

@interface Protocol : NSObject

           ^

SRProxy.m:419:70: error: no member named 'types' in 'struct objc_object'

It seems that once we switch to 64Bit  descriptionForInstanceMethod: to no longer delivers a 

struct   objc_method_description

as it used to do but now a 

struct   objc_object

which seems completely wrong!??

Am I supposed to encountered that kind of difficulties when going to 64Bit in 2019? I thought I was the last one running 32Bit code!?

On GNUstep I use

            struct objc_method_description desc;

            desc = GSProtocolGetMethodDescriptionRecursive(_protocol, aSelector, YES, YES);

            if (desc.name == NULL && desc.types == NULL)

              {

               desc = GSProtocolGetMethodDescriptionRecursive(_protocol, aSelector, YES, NO);

              }

            types = desc.types;

for getting the types. I haven’t tried that with -m64 yet.

Any idea what this is all about and how to fix it?

Thanks a lot,

 Andreas