[lldb-dev] Trying to understand AppleObjCRuntimeV1::CreateObjectChecker

[Nat! via lldb-dev]

Hi

is this funny function  AppleObjCRuntimeV1::CreateObjectChecker actually 
used ?

First of all the snprintf is wrapped in an assert (!?). If the code gets 
compiled with -DNDEBUG, the function would pretty much do nothing.

Second, I guess, that this is some C-code that gets compiled on the fly, 
It seems to do nothing. I guess the code has a chance of crashing, if 
the parameter is not really an object. The debugger could notice that 
and figure out, that it's not an object. But guessing is not knowing... :)

Ciao
   Nat!


```
struct BufStruct {
     char contents[2048];
};

UtilityFunction *
AppleObjCRuntimeV1::CreateObjectChecker(const char *name)
{
     std::unique_ptr<BufStruct> buf(new BufStruct);

     assert(snprintf(&buf->contents[0], sizeof(buf->contents),
                     "struct __objc_class 
                      \n"
                     "{ 
                      \n"
                     "   struct __objc_class *isa; 
                      \n"
                     "   struct __objc_class *super_class; 
                      \n"
                     "   const char *name; 
                      \n"
                     "   // rest of struct elided because unused 
                      \n"
                     "}; 
                      \n"
                     " 
                      \n"
                     "struct __objc_object 
                      \n"
                     "{ 
                      \n"
                     "   struct __objc_class *isa; 
                      \n"
                     "}; 
                      \n"
                     " 
                      \n"
                     "extern \"C\" void 
                      \n"
                     "%s(void *$__lldb_arg_obj, void 
*$__lldb_arg_selector)                  \n"
                     "{ 
                      \n"
                     "   struct __objc_object *obj = (struct 
__objc_object*)$__lldb_arg_obj; \n"
                     "   (int)strlen(obj->isa->name); 
                      \n"
                     "} 
                      \n",
                     name) < (int)sizeof(buf->contents));

     Error error;
     return GetTargetRef().GetUtilityFunctionForLanguage(buf->contents, 
eLanguageTypeObjC, name, error);
}
```