On Phobos GC hunt

[Dmitry Olshansky via Digitalmars-d]

On Tuesday, 7 October 2014 at 21:59:08 UTC, Peter Alexander wrote:
> On Tuesday, 7 October 2014 at 20:13:32 UTC, Jacob Carlborg 
> wrote:
>> I didn't look at any source code to see what "new" is actually 
>> allocating, for example.
>
> I did some random sampling, and it's 90% exceptions, with the 
> occasional array allocation.
>

That's interesting. I suspected around 50%. Well that's even 
better since if we do ref-counted exceptions we solve 90% of 
problem ;)

> I noticed that a lot of the ~ and ~= complaints are in code 
> that only ever runs at compile time (generating strings for 
> mixin). I wonder if there's any way we can silence these false 
> positives.

I'm going to use blacklist for these as compiler can't in general 
know if it is going to be used exclusively at CTFE or not.

Okay,  I think I should go a bit futher with the second version 
of the tool.

Things on todo list:
  - make tool general enough to work for any GitHub based project 
(and hackable for other hostings)
  - use Brian's D parser to accurately find artifacts
  - detect "throw new SomeStuff" pattern and automatically 
populate potential fix line
  - list all source links in one coulmn for the same function 
(this needs proper parser)
  - use blacklist of <module-name>:<artifact name> to filter out 
CTFE
  - use current data from wiki for "potential fix" column if 
present

Holy grail is:
  - plot DOT call-graph of GC-users, with leafs being the ones 
reported by -vgc. So I start with this list then add functions 
them, then functions that use these functions and so on.