en Copyright 2015 Java http://172.16.0.5:8080/history/wasmtime-44.0.1/cranelift/reader/#2f7dbd61 PCC: remove proof-carrying code (for now?). (#12800)In late 2023, we built out an experimental feature calledProof-Carrying Code (PCC), where we attached "facts" to values in theCLIF IR and built verification of these facts after lowering tomachine instructions. We also added "memory types" describing layoutof memory and a "checked" flag on memory operations such that we couldverify that any checked memory operation accessed valid memory (asdefined by memory types attached to pointer values viafacts). Wasmtime's Cranelift backend then put appropriate memory typesand facts in its IR such that all accesses to memory (aspirationally)could be checked, taking the whole mid-end and lowering backend ofCranelift out of the trusted core that enforces SFI.This basically worked, at the time, for static memories; but never fordynamic memories, and then work on the feature lostprioritization (aka I had to work on other things) and I wasn't ableto complete it and put it in fuzzing/enable it as a production option.Unfortunately since then it has bit-rotted significantly -- as we addnew backend optimizations and instruction lowerings we haven't keptthe PCC framework up to date.Inspired by the discussion in #12497 I think it's time to deleteit (hopefully just "for now"?) unless/until we can build it again. Andwhen we do that, we should probably get it to the point of validatingrobust operation on all combinations of memory configurations beforemerging. (That implies a big experiment branch rather than a bunch ofeager PRs in-tree, but so it goes.) I still believe it is possible tobuild this (and I have ideas on how to do it!) but not right now. List of files: /wasmtime-44.0.1/cranelift/reader/src/parser.rs Tue, 31 Mar 2026 04:00:00 +0000 Chris Fallin <chris@cfallin.org> http://172.16.0.5:8080/history/wasmtime-44.0.1/cranelift/reader/#f302ebd6 Release Wasmtime 44.0.1 (#13241)[automatically-tag-and-release-this-commit]Co-authored-by: Wasmtime Publish <wasmtime-publish@users.noreply.github.com> List of files: /wasmtime-44.0.1/cranelift/reader/Cargo.toml Thu, 30 Apr 2026 15:00:00 +0000 wasmtime-publish <59749941+wasmtime-publish@users.noreply.github.com>