Upstream the "DWARF for WebAssembly" spec?

[eqrion]

Yury has a "DWARF for WebAssembly" spec on his personal repo. It's linked in the Debugging.md file on this repo. We'd like to find a better home for this. I'm not quite sure this is the best spot, but not sure what would be better.

Do people think it makes sense to upstream this to here?

cc @yurydelendik @dschuff

[eqrion]

We're also not sure if the current support in LLVM still matches the document. So it might also need updates, which would be independently worthwhile.

[tschneidereit]

cc @cfallin, who might be able to a bit more about where LLVM is at relative to the document

[cfallin]

Honestly I haven't looked much into LLVM's DWARF usage in Wasm modules. (I know the gdbstub protocol extensions in detail, but LLDB pulls modules over that protocol and reads its own DWARF so that much is an opaque box from my work's point of view -- sorry!)

[dschuff]

IIRC LLVM is still pretty close to the document. @aheejin has done a bit of tuning in the backend of how the internal information is handled, but I don't recall there being changes to the way the DWARF is encoded in a long time. We might want to check on Wasm64 at some point, I'm not sure we've tested that much with the Chrome Devtools plugin.

[dschuff]

oh and to answer the OP, I do think it makes sense for the doc to be here.

[aheejin]

Yeah, I've worked on increasing debug info coverage a few years ago, but that didn't involve changing the DWARF Wasm spec.

[eqrion]

Okay, it sounds like there's enough consensus to merge something here. I'll work with Yury to have a PR open sometime.