Bug #7554

Updated by Koichi Sasada over 2 years ago

In some case (using singleton method),
TracePoint#defined_class doesn't return Class or Module.

# example
def self.foo
end

obj = Object.new

def obj.foo
end

module M
def baz
end
end

class C
include M
def self.bar
end
end

TracePoint.trace(:call){|tp|
p [tp.defined_class, tp.defined_class.kind_of?(Module)]
}

foo
obj.foo
C.bar
C.new.baz

#=>
# ruby 2.0.0dev (2012-12-01 trunk 38127) [i386-mswin32_100]
[main, false]
[#<Object:0x2d8267c>, false]
[C, true]
[M, true]

###

The name `defined_class' expected to return object of Class or Module.
So it should be return Class or Module.

Current code returns modified object by singleton class.
I propose to return singleton class directly.

The following patch fixes this issue.

###
Index: vm_trace.c
===================================================================
--- vm_trace.c (revision 38362)
+++ vm_trace.c (working copy)
@@ -712,9 +712,6 @@
if (RB_TYPE_P(trace_arg->klass, T_ICLASS)) {
trace_arg->klass = RBASIC(trace_arg->klass)->klass;
}
- else if (FL_TEST(trace_arg->klass, FL_SINGLETON)) {
- trace_arg->klass = rb_iv_get(trace_arg->klass, "__attached__");
- }
}
else {
trace_arg->klass = Qnil;
###

After that, that script shows:

###
[#<Class:#<Object:0x874b244>>, true]
[#<Class:#<Object:0x873f9a8>>, true]
[#<Class:C>, true]
[M, true]
###

The current Current behavior is from `set_trace_func' (6th parameter of block).
I'm not sure why it returns modified object instead of singleton class.


I believe TracePoint#defined_class should return singleton class directly.
But TracePoint is introduced from 2.0, so newer, no compatibility compatible issue.

Back