Method lookup meta-error on classes

[Util]

Reported by: zefram@fysh.org

When a named method is called on an object, but the invocant class doesn't define a method of that name, an error message is generated. Normally the error message refers to the class of the invocant, but if the invocant is a class object then the error message gets it wrong: it shows the name of the class represented by the invocant object instead of the class of the invocant. If the invocant is an anonymous class then a completely different error message is generated.

In these examples (correct behaviour and then the two incorrect cases), I use typeof on the invocant to show what class name should appear in the error message that comes from the method call.

$ cat t48.pir 
.sub main :main
       $P0 = newclass "Foo"
       $P1 = new $P0
       $S0 = typeof $P1
       say $S0
       $P2 = $P1."wibble"()
.end

$ ./parrot t48.pir 
Foo
Method 'wibble' not found for invocant of class 'Foo'
current instr.: 'main' pc 17 (t48.pir:6)

$ cat t47.pir 
.sub main :main
       $P0 = newclass "Foo"
       $P1 = subclass $P0, "Bar"
       $S0 = typeof $P1
       say $S0
       $P2 = $P1."wibble"()
.end

$ ./parrot t47.pir 
Class
Method 'wibble' not found for invocant of class 'Bar'
current instr.: 'main' pc 18 (t47.pir:6)

$ cat t45.pir 
.sub main :main
       $P0 = newclass "Foo"
       $P1 = subclass $P0
       $S0 = typeof $P1
       say $S0
       $P2 = $P1."wibble"()
.end

$ ./parrot t45.pir 
Class
Attempt to create PMC Proxy for invalid type number = 0!
current instr.: 'main' pc 17 (t45.pir:6)

-zefram

Summary of my parrot 5.7.0 configuration:
 configdate='Sat Oct  5 12:42:43 2013 GMT'
 Platform:
   osname=linux, archname=x86_64-linux-gnu-thread-multi
   perl=/usr/bin/perl