Stream: git-wasmtime

Topic: wasmtime / Issue #53 Write .debug_frame information

view this post on Zulip Wasmtime GitHub notifications bot (Mar 07 2020 at 11:18):

tschneidereit commented on Issue #53:

@yurydelendik what's the status of this PR, are there parts that we should still land, or is this superseded by things that landed in the meantime?

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2020 at 14:16):

yurydelendik commented on Issue #53:

what's the status of this PR, are there parts that we should still land, or is this superseded by things that landed in the meantime?

There is no direct need in writing .debug_frame information -- debuggers now can successfully guess frame backtrace. Though I would like to convert this PR into "write .eh_frame information" issue -- there is a change we will need this information for cranelift's wasm exception handling.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2020 at 14:18):

tschneidereit commented on Issue #53:

Ok, makes sense. Should we perhaps close this PR and you open a new one with that new purpose, though?

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2020 at 14:26):

bjorn3 commented on Issue #53:

debuggers now can successfully guess frame backtrace

Last time I checked, gdb couldn't guess it when opt_level=none is used, because it didn't understand redundant rex prefixes for push rbp.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2020 at 14:52):

yurydelendik commented on Issue #53:

gdb couldn't guess it when opt_level=none is used, because it didn't understand redundant rex prefixes for push rbp.

Soon I'm about to dive into compatibility with GDB, and I would like to track that independently in separate bug(s). AFAIK rex issue was addressed, at least for LLDB. I will rebase this PR anyway, e.g. to check the theory that it will help with GDB.

view this post on Zulip Wasmtime GitHub notifications bot (Mar 09 2020 at 14:59):

bjorn3 commented on Issue #53:

For reference: https://github.com/bjorn3/rustc_codegen_cranelift/issues/146#issuecomment-449474527

view this post on Zulip Wasmtime GitHub notifications bot (Mar 10 2020 at 13:26):

yurydelendik commented on Issue #53:

@bjorn3 I rebased the PR. At this I know there is plenty of code duplication, e.g. with writing fde or map_reg, but it can be used to produce object file with the proper .debug_frame.

Maybe after its landing, we can refactor it for .eh_frame support and move to the cranelift ?

view this post on Zulip Wasmtime GitHub notifications bot (Mar 10 2020 at 14:49):

yurydelendik edited a comment on Issue #53:

@bjorn3 I rebased the PR. At this momennt I know there is plenty of code duplication, e.g. with writing fde or map_reg, but this PR can be used to produce object file with the proper .debug_frame.

Maybe after its landing, we can refactor it for .eh_frame support and move to the cranelift ?

Last updated: Dec 23 2024 at 12:05 UTC