-
Notifications
You must be signed in to change notification settings - Fork 12.9k
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Recommend to never display zero disambiguators when demangling v0 symbols #124514
Recommend to never display zero disambiguators when demangling v0 symbols #124514
Conversation
rustbot has assigned @GuillaumeGomez. Use |
cc @ehuss, as the original author of these (incredible) docs. |
r? eddyb |
@eddyb, would you like me to make any changes to this PR before it can be approved? |
@_eddyb seems to be unavailable at the moment. r? @davidtwco maybe? |
@bors r+ rollup |
…kingjubilee Rollup of 16 pull requests Successful merges: - rust-lang#123374 (DOC: Add FFI example for slice::from_raw_parts()) - rust-lang#124514 (Recommend to never display zero disambiguators when demangling v0 symbols) - rust-lang#125978 (Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking) - rust-lang#125980 (Nvptx remove direct passmode) - rust-lang#126187 (For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.) - rust-lang#126210 (docs(core): make more const_ptr doctests assert instead of printing) - rust-lang#126249 (Simplify `[T; N]::try_map` signature) - rust-lang#126256 (Add {{target}} substitution to compiletest) - rust-lang#126263 (Make issue-122805.rs big endian compatible) - rust-lang#126281 (set_env: State the conclusion upfront) - rust-lang#126286 (Make `storage-live.rs` robust against rustc internal changes.) - rust-lang#126287 (Update a cranelift patch file for formatting changes.) - rust-lang#126301 (Use `tidy` to sort crate attributes for all compiler crates.) - rust-lang#126305 (Make PathBuf less Ok with adding UTF-16 then `into_string`) - rust-lang#126310 (Migrate run make prefer rlib) - rust-lang#126314 (fix RELEASES: we do not support upcasting to auto traits) r? `@ghost` `@rustbot` modify labels: rollup
Rollup merge of rust-lang#124514 - michaelwoerister:zero-disambiguator-demangling-recommendation, r=davidtwco Recommend to never display zero disambiguators when demangling v0 symbols This PR extends the [v0 symbol mangling documentation](https://doc.rust-lang.org/rustc/symbol-mangling/v0.html) with the strong recommendation that demanglers should never display zero-disambiguators, especially when dealing with `crate-root`. Being able to rely on `C3foo` to be rendered as `foo` (i.e. without explicit disambiguator value) rather than as `foo[0]` allows the compiler to encode things like new basic types in a backward compatible way. This idea has been originally proposed by `@eddyb` in [the discussion around supporting `f16` and `f128` in the v0 mangling scheme](rust-lang#122106). It is a generally useful mechanism for supporting a certain class of new elements in the v0 mangling scheme in a backward compatible way (whether as a temporary workaround until downstream tooling has picked up grammar changes or as a permanent encoding). cc `@tgross35`
…kingjubilee Rollup of 16 pull requests Successful merges: - rust-lang#123374 (DOC: Add FFI example for slice::from_raw_parts()) - rust-lang#124514 (Recommend to never display zero disambiguators when demangling v0 symbols) - rust-lang#125978 (Cleanup: HIR ty lowering: Consolidate the places that do assoc item probing & access checking) - rust-lang#125980 (Nvptx remove direct passmode) - rust-lang#126187 (For E0277 suggest adding `Result` return type for function when using QuestionMark `?` in the body.) - rust-lang#126210 (docs(core): make more const_ptr doctests assert instead of printing) - rust-lang#126249 (Simplify `[T; N]::try_map` signature) - rust-lang#126256 (Add {{target}} substitution to compiletest) - rust-lang#126263 (Make issue-122805.rs big endian compatible) - rust-lang#126281 (set_env: State the conclusion upfront) - rust-lang#126286 (Make `storage-live.rs` robust against rustc internal changes.) - rust-lang#126287 (Update a cranelift patch file for formatting changes.) - rust-lang#126301 (Use `tidy` to sort crate attributes for all compiler crates.) - rust-lang#126305 (Make PathBuf less Ok with adding UTF-16 then `into_string`) - rust-lang#126310 (Migrate run make prefer rlib) - rust-lang#126314 (fix RELEASES: we do not support upcasting to auto traits) r? `@ghost` `@rustbot` modify labels: rollup
This PR extends the v0 symbol mangling documentation with the strong recommendation that demanglers should never display zero-disambiguators, especially when dealing with
crate-root
.Being able to rely on
C3foo
to be rendered asfoo
(i.e. without explicit disambiguator value) rather than asfoo[0]
allows the compiler to encode things like new basic types in a backward compatible way. This idea has been originally proposed by @eddyb in the discussion around supportingf16
andf128
in the v0 mangling scheme. It is a generally useful mechanism for supporting a certain class of new elements in the v0 mangling scheme in a backward compatible way (whether as a temporary workaround until downstream tooling has picked up grammar changes or as a permanent encoding).cc @tgross35