I found running the buildsymbols step locally that running dsymutil on libxul takes significantly longer than dumping symbols for the rest of the binaries, so by the time we run dump_syms on libxul everything else is done and we're only utilizing one core. Locally using llvm-dsymutil in place of /usr/bin/dsymutil cuts the whole thing down from 10 minutes to about 6 (this usually take 15-25 minutes in automation).

Similarly compelling time savings in https://treeherder.mozilla.org/#/jobs?repo=try&revision=ced4a01b3f1e (debug down from 15 to 7 minutes, opt from 25 to 11), but a flood of warnings like: 20:47:35 INFO - 2015-10-16 20:47:35: dwarf_cu_to_module.cc:584: INFO: dist/bin/XUL.dSYM/Contents/Resources/DWARF/XUL: the DIE at offset 0xd326de1 has a DW_AT_abstract_origin attribute referring to the die at offset 0xd326e19, which either was not marked as an inline, or comes later in the file 20:47:35 INFO - 2015-10-16 20:47:35: dwarf_cu_to_module.cc:633: INFO: dist/bin/XUL.dSYM/Contents/Resources/DWARF/XUL: warning: function at offset 0xd326de1 has no name

Actually those same warnings are on trunk. llvm-dsymutil is the default in xcode 7, so maybe it's ready.

Guess we should just do this. I'll try a quick sanity check on a local build to see if the dump_syms output is the same. FYI, you shouldn't need to add anything to the tooltool manifest, llvm-dsymutil is already in the clang package we use (now that we're on a new enough clang version), so you can just use $topsrcdir/clang/bin/llvm-dsymutil.

Oh, that was updated Friday, nice! I found some differences in the sym files when I looked at this briefly yesterday. I guess it's possible not all the relevant patches are upstream.

I just tried this with the version of clang that I had updated our official builds to (ehsan has since updated to a slightly-newer build): $ ~/clang/bin/llvm-dsymutil -version LLVM (http://llvm.org/): LLVM version 3.8.0svn The .dSYM bundles aren't bit-identical, but the output of dump_syms is identical, which is good enough for me!

bug 1215748 - use llvm-dsymutil for mac builds. r?mshal

Comment on attachment 8676927 [details] MozReview Request: bug 1215748 - use llvm-dsymutil for mac builds. r?mshal https://reviewboard.mozilla.org/r/22835/#review20471

https://hg.mozilla.org/integration/mozilla-inbound/rev/11d88c9683e58c28f417a9122c2101ea66edeba9 bug 1215748 - use llvm-dsymutil for mac builds. r=mshal