How to set breakpoints at class-methods without editing source of
library files? And without line numbers?
$ cat test.rb
require ‘ruby-debug’
class Aaa
def self.cl_aaa
puts ‘A A A’
end
def initialize @aaa = ‘a a a’
end
def aaa
puts @aaa
end
end
debugger
a = Aaa.new
Aaa.cl_aaa
a.aaa
$ ruby test.rb
< or >
$ rdebug test.rb
test.rb:
a = Aaa.new
(rdb:1) b Aaa:cl_aaa
Breakpoint 1 at Aaa::cl_aaa
(rdb:1) b Aaa:aaa
Breakpoint 2 at Aaa::aaa
(rdb:1) i b
Num Enb What
1 y at Aaa:cl_aaa
2 y at Aaa:aaa
(rdb:1) cont
A A A
Breakpoint 2 at Aaa:aaa
test.rb:<lineno of ‘def aaa’>
def aaa
(rdb:1) i b
Num Enb What
1 y at Aaa:cl_aaa
2 y at Aaa:aaa
breakpoint already hit 1 time
(rdb:1) cont
a a a
$
The same result if it was used ‘#’ or ‘.’ instead of ‘:’, i.e.
‘Class#method’ or ‘Class.method’.
It is normal. Because class A is not defined at this point yet. In case
when rdebug is lauched, it stops at the first line. But it is possible
to set break at any line of source by line number.
In your opinion, what does the rest of the debug session do?
But why ruby-debug does not stop at class-methods when class is already
loaded, though it stops at instance-methods?
The debugger won’t stop at instance methods for me:
It is normal. Because class A is not defined at this point yet. In case
when rdebug is lauched, it stops at the first line. But it is possible
to set break at any line of source by line number.
But why ruby-debug does not stop at class-methods when class is already
loaded, though it stops at instance-methods?
How to set breakpoints at class-methods without editing source of
library files? And without line numbers?
My recollection is that ruby-debug does not allow setting breakpoints
by method name. For that, you need to use the older debug.rb (in
ruby’s stdlib). Add -rdebug to the command line when you start the
interpreter. And you have to put up with the much slower performance
of debug.rb. (Often than doesn’t matter, tho.)
To 7stud. These are all normal, except class-method, as i wrote.
In you example ‘a.sayhi’ and especially ‘sayhi’ - is not correct
refernces to instance metod. But ‘A.sayhi’ is it. Or ‘A:sayhi’, or
‘A#sayhi’.
You should better understand the difference between class and instanse
methods.
It is all ok. Except subject of these posts.
I don’t know about rdebug in this case (I can’t remember trying to set
breakpoints on method names, I usually just use the line number or set
the breakpoint in textmate using the rubyamp bundle), but normal
nomenclature, given a class A
A#meth - refers to an instance method of A
A::meth - refers to a class method of A (note the double colon)
This is what RI uses. RI also appears to accept
A.meth
which will give documentation on an instance method named meth is A
has one, or if not a class method named meth if there is one.
For example ri IO.read gives info on IO#read (IO has both IO::read
and IO#read), while IO.select gives info on IO::select
Fixed in ruby-debug 1.9 (although it hasn’t uploaded yet; GitHub is
pretty slow today). I’ve also submitted a patch to RubyForge for 1.8.
I’m curious: if the feature is valuable, why not make it more general
and have break stop at a match to a specified string or a regex, for
example:
break “a.sayhi”
or
break /a.sayhi/
Well, that’s certainly possible, but at first glance, that to me looks
like feature-itis. IOW, I don’t know that it’s terribly useful, and it
might tend to confuse users. I could be wrong.
I don’t know about rdebug in this case (I can’t remember trying to set
breakpoints on method names, I usually just use the line number or set
the breakpoint in textmate using the rubyamp bundle), but normal
nomenclature, given a class
A#meth - refers to an instance method of A
A::meth - refers to a class method of A (note the double colon)
This is what RI uses. RI also appears to accept
A.meth
which will give documentation on an instance method named meth is A
has one, or if not a class method named meth if there is one.
For example ri IO.read gives info on IO#read (IO has both IO::read
and IO#read), while IO.select gives info on IO::select
And RI doesn’t appear to understand A:meth
I know about conventions. And know about theoretical difference between
class and instance methods. And also know that rdebug does not fully
correspond these lexical conventions.
But this case in point is technical aspects of rdebug. Though I do not
say anything against possibility of better syntax.
As it is seen, when during setting breakpoint it is pointed to some
class and some method (no matter in which syntax), rdebug at runtime
checks the class existing and just remembers the method name for later
binding without checking.
The problem is what later rdebug searches the method only in the
dictionary of instance methods of the class, but neither of
class-methods nor in dictionary singleton methods. I do not know how
these dictionaries are realized, I just see the fact.
I suppose what class methods and singleton methods of class-object are
the same things.
Well, that’s certainly possible, but at first glance, that to me looks
like feature-itis. IOW, I don’t know that it’s terribly useful, and it
might tend to confuse users. I could be wrong.
Is it possible to make so that one can set breakpoints at any Method or
Proc instance, or at any object with “breakable” interface at all?
It may be to make two modes of debugger for ordinary and experienced
users.
Or else it will not be known, is it needed or not, until someone will be
able to play with it. Only practice may show it, if someone will get
this freedom.
Unfortunately, on my distro they have not yet made friendship between
1.8 and 1.9, rubygems conflicts And I am depending on 1.8 now. So I
shall not have been able to test it on 1.9 at nearly time.
A backport to 1.8 might be possible; hard to say at this point.
Thank you for your attention. I shall have done it as soon as I can. I
shall have tryed to better formulate the request.
Unfortunately, on my distro they have not yet made friendship between
1.8 and 1.9, rubygems conflicts And I am depending on 1.8 now. So I
shall not have been able to test it on 1.9 at nearly time.
Ok. I shall have practised in it anyway, because it is needed to me.
Just a little shall learn tracing interface of objects. I think it must
be an elegant solution without any hack. Or else why does tracing
interface need, if it is not used completely by debugger.
I can’t write on Python anymore after I have known Ruby better
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And I am depending on 1.8 now. So I
And I am depending on 1.8 now. So I