Enable folly::Symbolizer for HHVM #123
Conversation
| # libgcc_s dependency is already part of HHVM, this enforces the | ||
| # order in which the libraries are linked. | ||
| if (ENABLE_FOLLY_SYMBOLIZER) | ||
| SET(UNWIND_LIB -lgcc_s -lunwind) |
There was a problem hiding this comment.
Do you know what happens on mac (clang) with and without this?
There was a problem hiding this comment.
I have not tested on either mac or clang, which is why I protected this option under GCC in the related PR in HHVM: facebook/hhvm#8123
Do you think it is better to include the GCC requirement in folly as well?
There was a problem hiding this comment.
We don't actually use Folly's build system - but given that https://github.com/facebook/folly/blob/9656bacc814ce9efd24e178ed5e127c5c365a248/CMake/FollyConfigChecks.cmake checks for elf.h , mac's most likely not going to be an issue - but Clang should work.
cc @simpkins
There was a problem hiding this comment.
@fredemmott can you please clarify if I should change anything for Clang?
This change depends on hhvm/hhvm-third-party#123, which enables 2 additional source files to be compiled and adds libunwind as a dependency for folly. The "-lgcc_s" added before "-lunwind" is used to solve a linking order issue that causes "_Ux86_64_setcontext" to be called from libunwind instead of libgcc_s and messes up the signal mask (more details here http://savannah.nongnu.org/bugs/?48486). The libgcc_s dependency is already part of HHVM, this change enforces the order in which the libraries are linked. By enabling folly::Symbolizer, HHVM will show debug symbols (in stacktraces, perf, GDB) when huge pages are enabled (default behavior for open source builds). Also, one nice side-effect is that this change causes HHVM to show symbols in backtraces (after a crash) for non-huge-pages builds, which were missing for some reason.
|
I've re-triggered the build; not sure if that's sufficient or a rebase will be needed. |
mofarrell
force-pushed
the
master
branch
6 times, most recently
from
e4cba51 to
1845927
Compare
This PR enables support for folly::Symbolizer in HHVM if the ENABLE_FOLLY_SYMBOLIZER variable is set to ON.