679031 - Expose jsdbg2 Debugger object as an XPCOM component

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jason Orendorff [:jorendorff]]

Dave Camp wrote code to do this. It works like so:

  var xpcDebugger = Cc["@mozilla.org/jsdebugger;1"].getService(Ci.nsIJSDebugger);
  xpcDebugger.addClass();

The addClass() method modifies the current global, adding a Debugger constructor. Then you can do stuff like:

  var dbg = new Debugger(anyContentWindow);
  dbg.onDebuggerStatement = function (frame) {
      alert("this is your debugger speaking");
  };
  anyContentWindow.setTimeout("debugger;", 0);

We have the code, with some tests even. We can expose this stuff to extension developers for FF8.

Comment 1

[Jason Orendorff [:jorendorff]]

Attachment: WIP 1

This is what Dave Camp hacked together. I got several useful comments on IRC about the approach, so I'm going to rearrange it completely and post a new patch. :)

Comment 2

[Panos Astithas (he/him) [:past] (please ni?)]

Note that I've updated these tests to work with the new Debugger API (onDebuggerStatement, etc.) in bug 676605. The fixes are still a WIP, but you can find them in my patch queue:

https://hg.mozilla.org/users/pastithas_mozilla.com/remote-debug-patches

Comment 4

[Jason Orendorff [:jorendorff]]

Attachment: WIP 2

This one passes tests. The new .jsm was one of the IRC recommendations I got.

The other is to move the whole thing under the js/ directory. I think maybe js/components/{ctypes,debugger,reflect}, though I'll do the other two separately.

Comment 5

[Jason Orendorff [:jorendorff]]

Attachment: v3

I don't know who likes to give reviews and super-reviews on new components like this. Feel free to dodge, as long as there's someone standing behind you.

Comment 6

[Benjamin Smedberg]

Comment on attachment 553992 [details] [diff] [review]
v3

Please use straight js/debugger. components/ is an unfortunate artifact of directory history we should avoid.

Comment 7

[Jason Orendorff [:jorendorff]]

I don't want to use js/debugger because that directory name looks like there might be something interesting in there, which would be totally untrue--it's just unloved glue code.

So following tense negotiations on IRC, bsmedberg and I have settled on
js/ductwork/debugger. Seriously.

Later I'll move toolkit/ctypes and toolkit/reflect under js/ductwork, and we can then happily forget about them until the revolution comes.

Comment 8

[Jason Orendorff [:jorendorff]]

Attachment: v4 - same as v3 but rename js/components to js/ductwork

Carrying forward bsmedberg's sr+.

Comment 9

[Jason Orendorff [:jorendorff]]

Actually it's not quite the same. v4 removes enter/exitNestedEventLoop and eventLoopNestLevel, at dcamp's encouragement.

Comment 10

[(not currently active) Ted Mielczarek]

Comment on attachment 554366 [details] [diff] [review]
v4 - same as v3 but rename js/components to js/ductwork

Review of attachment 554366 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/ductwork/Makefile.in
@@ +19,5 @@
> +# the Initial Developer. All Rights Reserved.
> +#
> +# Contributor(s):
> +#  Brian Ryner <[e-mail]>
> +#  Benjamin Smedberg <[e-mail]>

I'm sure you copy-pasted these from somewhere, but you can probably remove the contributors from these new files you're adding, since they're pretty much all yours. Also, change copyright dates to 2011 while you're copy-pasting?

::: js/ductwork/debugger/Makefile.in
@@ +55,5 @@
> +IS_COMPONENT = 1
> +
> +CPPSRCS = \
> +    nsJSDebugger.cpp \
> +    $(NULL)

Two-space indent after line continuations, please.

@@ +64,5 @@
> +    $(NULL)
> +
> +EXTRA_JS_MODULES = \
> +	jsdebugger.jsm \
> +	$(NULL)

Two-space, as above, and please don't use actual tabs in Makefiles except before rule commands where they're required.

@@ +72,5 @@
> +	$(NULL)
> +
> +ifdef ENABLE_TESTS
> +    DIRS += tests
> +endif

It's not really typical to indent inside conditionals in Makefiles, but I don't have strong feelings against it if you like it.

::: toolkit/components/ctypes/ctypes.jsm
@@ +52,5 @@
>  
> +// Initialize the Debugger object. You do not need to do this yourself.
> +const init = Components.classes["@mozilla.org/jsdebugger;1"].createInstance(Components.interfaces.nsIJSDebugger);
> +init.addClass();
> +Debugger.util = init;

Is there a reason this has a two-step init? I assume addClass adds Debugger, but why can't it setup its own .util?

Not super-worried about this, this is all awful ductwork that we really ought to rip out and replace with something better.

::: js/ductwork/debugger/nsJSDebugger.cpp
@@ +1,1 @@
> +/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */

Dare to dream and leave off the ns prefix?

::: js/ductwork/debugger/tests/Makefile.in
@@ +44,5 @@
> +include $(DEPTH)/config/autoconf.mk
> +
> +MODULE          = test_debugger
> +
> +XPCSHELL_TESTS = unit

You could feasibly move this up a level and just have XPCSHELL_TESTS = tests in js/ductwork/debugger/Makefile.in, which would save us a make invocation.

Comment 11

[Jason Orendorff [:jorendorff]]

OK, I made all those changes, except that

(In reply to Ted Mielczarek [:ted, :luser] from comment #10)
> Is there a reason this has a two-step init? I assume addClass adds Debugger,
> but why can't it setup its own .util?

I ripped this out in v4.

I'll land this tonight.

Comment 12

[Jason Orendorff [:jorendorff]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/28dd46b9ee31

Comment 13

[Jason Orendorff [:jorendorff]]

I backed it out. The test fails! Which is pretty annoying--it doesn't fail here. I'll look at it tomorrow morning.

Comment 14

[Jason Orendorff [:jorendorff]]

Ted figured it out for me. It was failing only after 'make package', due to a missing manifest entry for an xpt file.

So I added that, confirmed with Try server, and pushed.
http://hg.mozilla.org/integration/mozilla-inbound/rev/a0fb16f50677

Comment 15

[Ed Morley [:emorley]]

http://hg.mozilla.org/mozilla-central/rev/a0fb16f50677

Comment 16

[Eric Shepherd [:sheppy]]

Added a doc for the IJSDebugger interface, which strongly recommends not using it.

https://developer.mozilla.org/en/XPCOM_Interface_Reference/IJSDebugger