Stream: git-wasmtime

Topic: wasmtime / Issue #2357 cranelift: refactor unwind logic t...

view this post on Zulip Wasmtime GitHub notifications bot (Nov 06 2020 at 16:29):

uweigand commented on Issue #2357:

Hi @yurydelendik, just a quick question on the new RestoreFramePointer: shouldn't this reset the CFA to SP + initial_sp_offset, instead of whatever the current sp_offset is?

view this post on Zulip Wasmtime GitHub notifications bot (Nov 06 2020 at 16:36):

yurydelendik commented on Issue #2357:

new RestoreFramePointer: shouldn't this reset the CFA to SP + initial_sp_offset, instead of whatever the current sp_offset is?

IMHO it shall be SP + current sp_offset. In reality, it is initial_sp_offset = sp_offset, and we can add assert there.

At this moment, the input::UnwindCode values a chosen as subset to be able to produce Windows UNWIND_INFO and SystemV FDE. I suggest we will keep it this way until old existing backends implement unwind info (w/tests). We can refactor later.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 06 2020 at 16:36):

yurydelendik edited a comment on Issue #2357:

new RestoreFramePointer: shouldn't this reset the CFA to SP + initial_sp_offset, instead of whatever the current sp_offset is?

IMHO it shall be SP + current sp_offset. In reality, it is initial_sp_offset = sp_offset, and we can add assert there.

At this moment, the input::UnwindCode values a chosen as superset to be able to produce Windows UNWIND_INFO and SystemV FDE. I suggest we will keep it this way until old existing backends implement unwind info (w/tests). We can refactor later.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 06 2020 at 16:38):

yurydelendik edited a comment on Issue #2357:

new RestoreFramePointer: shouldn't this reset the CFA to SP + initial_sp_offset, instead of whatever the current sp_offset is?

IMHO it shall be SP + current sp_offset. In reality, it is initial_sp_offset = sp_offset, and we can add assert there.

At this moment, the input::UnwindCode values a chosen as subset/superset to be able to produce Windows UNWIND_INFO and SystemV FDE. I suggest we will keep it this way until old existing backends implement unwind info (w/tests). We can refactor later.

Last updated: Dec 23 2024 at 12:05 UTC