Forum: Ruby-core [ruby-trunk - Bug #7554][Open] TracePoint#defined_class doesn't return Class or Module

Issue #7554 has been reported by ko1 (Koichi Sasada).

----------------------------------------
Bug #7554: TracePoint#defined_class doesn't return Class or Module
https://bugs.ruby-lang.org/issues/7554

Author: ko1 (Koichi Sasada)
Status: Open
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category: core
Target version: 2.0.0
ruby -v: ruby 2.0.0dev (2012-12-01 trunk 38127) [i386-mswin32_100]


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.

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]
###

Current behavior is from `set_trace_func' (6th parameter of block).

But TracePoint is newer, no compatible issue.

Issue #7554 has been updated by ko1 (Koichi Sasada).

Description updated


----------------------------------------
Bug #7554: TracePoint#defined_class doesn't return Class or Module
https://bugs.ruby-lang.org/issues/7554#change-34696

Author: ko1 (Koichi Sasada)
Status: Open
Priority: Normal
Assignee: ko1 (Koichi Sasada)
Category: core
Target version: 2.0.0
ruby -v: ruby 2.0.0dev (2012-12-01 trunk 38127) [i386-mswin32_100]


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 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.
TracePoint is introduced from 2.0, so  no compatibility issue.