On 08/02/2017 05:43 PM, Jeff Law wrote:
I hate to throw in a wrench at this point, but has anyone looked at
dwgrep from Petr Machata? He's not doing much with it anymore, but it
might provide enough of a dwarf scanning framework to be useful for
testing purposes.
Sure, no problem: I first started talking publicly about this one week
ago, so it’s definitely not too late to mention alternatives. ;-) I
learned about dwgrep two years ago and forgot about it, so thank you for
the idea. I started to have a look at it, and for now I don’t think it’s
a good match in this context:
1. it’s an ELF only tool;
2. it must be built, requiring external dependencies: cmake and
elfutils;
3. in order to use it, one must learn a dedicated post-fix language
(Zwerg)
For 1. I think this is a true problem, as it means for instance that we
could not test DWARF on Windows and Darwin setups. Unless we add PE and
Mach-O handling in dwgrep of course, but that does not sound easy and
will bring other external dependencies.
For 3. I feel that, for someone who is comfortable with Python, it will
be easier to deal with a Python library (the dwarfutils in my patch)
than having to learn yet another DSL. I think that’s precisely why some
people would like to have a Python test framework rather than a TCL one.
Working with a “usual” imperative language looks easier than with
postfix expressions. Smaller cognitive load.
Actually I see another problem: pattern will have to vary depending on
the target platform (for instance 32/64bit or depending on the DWARF
version). Of course we could duplicate whole patterns in testcases to
take this into account, but that’s like code duplication: I think we
should be able to include small “X if 32bit else Y” in patterns, and I
don’t think we can do that with Zwerg (no way to pass something like
environment variables).
Of course, I have written a “competitor” tool: I guess my judgment is
biased. :-) So other opinions are welcome!
--
Pierre-Marie de Rodat
