www/firefox and valgrind

Hi

Just a quick heads up for an upcoming FreeBSD Firefox related item.

I maintain Valgrind and I’m getting close to fixing an issue that 
prevented FF from running under Valgrind

(https://bugs.kde.org/show_bug.cgi?id=464476)

FF has a bit of a special status in the Valgrind world as the two main 
contributors work at Mozilla.

I guess I’ll push a fix for this upstream this weekend. I don’t know 
exactly when I’m going to bump up the ports versions. “devel/valgrind” 
will likely change in April when Valgrind 3.21 gets released. I’m also 
thinking of making an intermediate release of “devel/valgrind-devel” in 
the next few weeks.

In the meantime I am seeing quite a lot of errors:

- _umtx_op syscall argument errors (probably a false positive and needs 
fixing in Valgrind)
- mismatched malloc/new/free/deletes (possibly class-specific operator 
noew?)
- some unrecognized instructions in wasm (surprisingly didn't cause 
SIGILL crashes)
- uninitiated bytes in sendmsg (generally throws up a lot of errors due 
to holes/padding in structures).

I suspect that points 2 and 3 are covered by
https://firefox-source-docs.mozilla.org/contributing/debugging/debugging_firefox_with_valgrind.html
which I hadn't seen and read before doing my first tests.

I may be opening some buzgilla items against firefox in the coming weeks.

I'll also give FF/Linux a go to see how noisy that is.

A+
Paul