1642121 - gdb prettyprinters not loaded if running from wrong directory

Status: RESOLVED FIXED

(Developer Infrastructure :: Developer Environment Integration, defect, P3)

Description

[Steve Fink [:sfink] [:s:]]

I started on this because I wanted JS pretty-printers in Pernosco. It scope-crept.

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.

Note that this still hardcodes the name "libxul.so" rather than using the platform-specific name. I figured this was fine because gdb is really only functional on Linux anyway. This limitation is pre-existing.

Comment 1

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1642121 - Remove directory dependence of GDB init files.

(removed redundant comment)

Note that there is a Rust debugging script gdb_load_rust_pretty_printers.py that is stored in the .debug_gdb_scripts section that will still not be found after this patch. I didn't try to tackle that. (That script looks like it ships with rustc, but nothing adds that directory to the search path. Maybe it does with a Rust main binary?)

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/df0d6b993ad6
Remove directory dependence of GDB init files. r=nalexander

Comment 3

[Noemi Erli[:noemi_erli]]

Backed out changeset df0d6b993ad6 (Bug 1642121) for causing build bustages

Push with failures: https://treeherder.mozilla.org/#/jobs?repo=autoland&group_state=expanded&selectedTaskRun=dItogkxKQBG3uLjjEMLEGw.0&resultStatus=testfailed%2Cbusted%2Cexception&revision=df0d6b993ad6feb4ebe87c69d630015466dbfeb5

Failure log: https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=306334366&repo=autoland&lineNumber=455

Backout: https://hg.mozilla.org/integration/autoland/rev/995cb36e46d49d74ec262dc7d85b4fb3497cd8f0

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4d8ee4696e13
Remove directory dependence of GDB init files. r=nalexander

Comment 5

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/4d8ee4696e13

Comment 6

[Steve Fink [:sfink] [:s:]]

(re-landed)