I wrote this patch to address two problems:
1. if I do `mach run` from a directory other than $topsrcdir, $objdir, or
$objdir/dist/bin, then .gdbinit will not be loaded.
2. Debugging the firefox binary will never load the JS prettyprinters in any
case.
I believe this patch fixes other problems as well, such as .gdbinit_python not being found, and the gdbpp pretty-printers not getting loaded in various situations.
The main changes of this patch are:
1. Move .gdbinit into build/ (and $objdir/build/) to delay it from getting
loaded until the search path is configured.
2. Move libxul.so-gdb.py into the correct directory.
3. Use either libxul.so-gdb.py or js-gdb.py to configure the correct
search path then load .gdbinit, and have .gdbinit load all of the
pretty-printers (Gecko and JS).
4. Use a single preprocessed file to configure the source directory. Use
relative paths within the objdir for everything else.
Differential Revision: https://phabricator.services.mozilla.com/D77589
Steve Fink