rust/compiler/rustc_serialize/src/collection_impls.rs, branch 1.60.0https://github.com/rust-lang/rust
http://git.dreamy.place/mirrors/rust/atom?h=1.60.02022-01-21T23:38:31+00:00Make `Decodable` and `Decoder` infallible.2022-01-21T23:38:31+00:00Nicholas Nethercoten.nethercote@gmail.com2022-01-18T02:22:50+00:00urn:sha1:416399dc1028545ea0ac6d68fb0b5cc5fa97d393
`Decoder` has two impls:
- opaque: this impl is already partly infallible, i.e. in some places it
currently panics on failure (e.g. if the input is too short, or on a
bad `Result` discriminant), and in some places it returns an error
(e.g. on a bad `Option` discriminant). The number of places where
either happens is surprisingly small, just because the binary
representation has very little redundancy and a lot of input reading
can occur even on malformed data.
- json: this impl is fully fallible, but it's only used (a) for the
`.rlink` file production, and there's a `FIXME` comment suggesting it
should change to a binary format, and (b) in a few tests in
non-fundamental ways. Indeed #85993 is open to remove it entirely.
And the top-level places in the compiler that call into decoding just
abort on error anyway. So the fallibility is providing little value, and
getting rid of it leads to some non-trivial performance improvements.
Much of this commit is pretty boring and mechanical. Some notes about
a few interesting parts:
- The commit removes `Decoder::{Error,error}`.
- `InternIteratorElement::intern_with`: the impl for `T` now has the same
optimization for small counts that the impl for `Result<T, E>` has,
because it's now much hotter.
- Decodable impls for SmallVec, LinkedList, VecDeque now all use
`collect`, which is nice; the one for `Vec` uses unsafe code, because
that gave better perf on some benchmarks.
Remove unused functions and arguments from rustc_serialize2021-06-01T17:29:11+00:00bjorn3bjorn3@users.noreply.github.com2021-06-01T17:12:55+00:00urn:sha1:a2c4affe860ec53647b902f257e7e575f0350854rustc_serialize: specialize opaque decoding of some u8 sequences2021-01-02T06:49:16+00:00Tyson Nottinghamtgnottingham@gmail.com2020-12-17T05:03:45+00:00urn:sha1:be79f493fb310b3a6b01ceada32713813bb12a91rustc_serialize: specialize opaque encoding of some u8 sequences2021-01-02T06:49:14+00:00Tyson Nottinghamtgnottingham@gmail.com2020-12-17T03:03:31+00:00urn:sha1:a4daa63a90f46e3c6e36efe5e0743eab09f6f12bmv compiler to compiler/2020-08-30T15:45:07+00:00markmarkm@cs.wisc.edu2020-08-28T03:58:48+00:00urn:sha1:9e5f7d5631b8f4009ac1c693e585d4b7108d4275