[Lldb-commits] [PATCH] D40475: DWZ 12/12: DWZ test mode

[Pavel Labath via lldb-commits]

On 30 November 2017 at 19:08, Jim Ingham <jingham at apple.com> wrote:
> We had a similar problem with the tests on macOS.  lldb has a facility that will do automatic lookup of UUID -> dSYM (macOS's separate debug info format) and if you are internal to Apple this will find all the system library debug info.  That will cause a handful of tests to fail, mostly because the presence of debug information changes stepping behavior.  doTest.py has a method: "checkDsymForUUIDIsNotOn" to ensure that this facility is turned off and if it is not will warn you and abort the test run.
>
> You are going to have to do something of that sort even once you get reading these libraries in to work, so I agree a setting seems like a good idea.  There is a setting for debug file search paths: target.debug-file-search-paths but I'd rather not add a special cookie to that since you can imagine wanting to point to a directory with your debug info and ALSO not read in the system debug info.  So it would be better IMO to add a parallel debug-file-avoid-directory setting.
>

I think the relevant logic here is in Host/common/Symbols.cpp, and
there it's just hard-coded to /usr/lib/debug, and does not respect any
settings. What I'd like to see one day is to move this piece of code
into the Platform class and add some "sysroot"-like setting that
controls it. This has a couple of benefits:
- it can be used for remote debugging (if you can a copy/nfs mount of
the remote system, you can just set sysroot to that)
- we can set this to /nonexistent for all tests, as you never want to
depend on that logic finding some debug info
- *except*, when you actually want to test this logic, and in that
case you can set the sysroot so some path that you have control of
- (I think) Stephane would be able to test D40539