[PATCH] D91203: [WebAssembly] Fixed wasm64 DWARF using 64-bit code pointer sizes

Thu Nov 12 09:23:52 PST 2020

yurydelendik added a comment.

In D91203#2391662 <https://reviews.llvm.org/D91203#2391662>, @aardappel wrote:

> @yurydelendik note that `wasm64` is an LLVM-level construct, in general Wasm we may one day have multiple memories, which means that "being 64-bit" is a property of each load/store instruction individually. So assuming we have a DWARF section associated with a possibly mixed mode Wasm module, there's no way to determine the size of `DW_AT_low_pc` or `DW_FORM_addr` from the module.
>
> Granted, this is a little hypothetical, since we don't know if `wasm-ld` will ever support such mixed linking (or another linker will), or wether DWARF will be output by non-LLVM producers, but the fact remains that Wasm really doesn't have an "architecture" in the same way as other ISAs.
>
> Thus, it seems easier to me to hard-code `DW_FORM_addr` to always be 32 or 64-bit for Wasm. Either choice is going to give the problem this patch is trying to address, though.

Agreed. My previous comment was more of a wish, and I have no opinion for this particular patch.

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https://reviews.llvm.org/D91203