1793562 - Investigate why synthesized symbols don't seem to be dumped correctly on macOS

Status: NEW

(Toolkit :: Crash Reporting, defect)

Description

[Gabriele Svelto [:gsvelto]]

See bug 1793538 comment 6. We've got a stack trace with the right addresses but wrong symbols. The correct symbols aren't actual function names but rather synthesized ones and they don't seem to be dumped correctly. It looks like Symbolic might be merging their address ranges within other public symbols.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:gsvelto, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 2

[Steven Michaud [:smichaud] (Retired)]

All the non-demangled symbols from bug 1795461 comment #0 have correct syntax. c++filt works on them. But, interestingly, you need to add an extra _ character to the beginning of each.

At least on macOS, all symbols in binaries have an extra underscore at the beginning. This is usually removed in "human readable" references to them -- for example stack traces. But c++filt only works on them if you add back the "extra" underscore.

I suspect synthesized symbols don't have the "extra" underscore, and that this is the root of our problem.

Comment 3

[Steven Michaud [:smichaud] (Retired)]

(Following up comment #2)

This may explain part of the problem, but it doesn't explain everything.