Return `ExitCode` from `rustc_driver::main` instead of calling `process::exit`
This makes rustc simply return an exit code from main rather than calling `std::process::exit` with an exit code. This means that drops run normally and the process exits cleanly. This is similar to what happens when an ICE occurs (due to being a panic that's caught by std's `lang_start`).
Also instead of hard coding success and failure codes this uses `ExitCode::SUCCESS` and `ExitCode::FAILURE`, which in turn effectively uses `libc::EXIT_SUCCESS` and `libc::EXIT_FAILURE` (via std). These are `0` and `1` respectively for all currently supported host platforms so it doesn't actually change the exit code.
This makes rustc simply return an exit code from main rather than calling `std::process::exit` with an exit code. This means that drops run normally and the process exits cleanly.
Also instead of hard coding success and failure codes this uses `ExitCode::SUCCESS` and `ExitCode::FAILURE`, which in turn effectively uses `libc::EXIT_SUCCESS` and `libc::EXIT_FAILURE` (via std). These are `0` and `1` respectively for all currently supported host platforms so it doesn't actually change the exit code.
rustc_errors: Add (heuristic) Syntax Highlighting for `rustc --explain`
This PR adds a feature that enables `rustc --explain <error>` to have syntax highlighted code blocks. Due to performance, size and complexity constraints, the highlighter is very heuristc, relying on conventions for capitalizations and such to infer what an identifier represents. The details for the implementation are specified below.
# Changes
1. Change `term::entrypoint` to `term::entrypoint_with_formatter`, which takes an optional third argument, which is a function pointer to a formatter. ([compiler/rustc_errors/src/markdown/mod.rs](https://github.com/rust-lang/rust/compare/main...JayanAXHF:rust:rustc_colored_explain?expand=1#diff-a6e139cadbc2e6922d816eb08f9e2c7b48304d09e6588227e2b70215c4f0725c))
2. Change `MdStream::write_anstream_buf` to be a wrapper around a new function, `MdStream::write_anstream_buf_with_formatter`, which takes a function pointer to a formatter. ([compiler/rustc_errors/src/markdown/mod.rs](https://github.com/rust-lang/rust/compare/main...JayanAXHF:rust:rustc_colored_explain?expand=1#diff-a6e139cadbc2e6922d816eb08f9e2c7b48304d09e6588227e2b70215c4f0725c))
3. Change [`compiler/rustc_driver_impl/src/lib.rs`](https://github.com/rust-lang/rust/compare/main...JayanAXHF:rust:rustc_colored_explain?expand=1#diff-39877a2556ea309c89384956740d5892a59cef024aa9473cce16bbdd99287937) to call `MdStream::write_anstream_buf_with_formatter` instead of `MdStream::write_anstream_buf`.
4. Add a `compiler/rustc_driver_impl/src/highlighter.rs` file, which contains the actual syntax highlighter.
# Implementation Details
1. The highlighter starts from the `highlight` function defined in `compiler/rustc_driver_impl/src/highlighter.rs`. It creates a new instance of the `Highlighter` struct, and calls its `highlight_rustc_lexer` function to start highlighting.
2. The `highlight_rustc_lexer` function uses `rustc_lexer` to lex the code into `Token`s. `rustc_lexer` was chosen since it preserves the newlines after scanning.
3. Based on the kind of token (`TokenKind`), we color the corresponding lexeme.
## Highlighter Implementation
### Identifiers
1. All identifiers that match a (non-exhaustive and minimal) list of keywords are coloured magenta.
2. An identifier that begins with a capital letter is assumed as a type. There is no distinction between a `Trait` and a type, since that would involve name resolution, and the parts of `rustc` that perform name resolution on code do not preserve the original formatting. (An attempt to use `rustc_parse`'s lexer and `TokenStream` was made, which was then printed with the pretty printer, but failed to preserve the formatting and was generally more complex to work with)
3. An identifier that is immediately followed by a parenthesis is recognized as a function identifier, and coloured blue.
## Literals
5. A `String` literal (or its corresponding `Raw`, `C` and `Byte` versions) is colored green.
6. All other literals are colored bright red (orange-esque)
## Everything Else
Everything else is colored bright white and dimmed, to create a grayish colour.
---
# Demo
<img width="1864" height="2136" alt="image" src="https://github.com/user-attachments/assets/b17d3a71-e641-4457-be85-5e5b1cea2954" />
<caption> Command: <code>rustc --explain E0520</code> </caption>
---
This description was not generated by an LLM (:p)
cc: @bjorn3
This commit adds a heuristics-based syntax highlighter for the `rustc
--explain` command. It uses `rsutc_lexer`'s lexer to parse input in
tokens, and matches on them to determine their color.
Remove `Deref`/`DerefMut` impl for `Providers`.
It's described as a "backwards compatibility hack to keep the diff small". Removing it requires only a modest amount of churn, and the resulting code is clearer without the invisible derefs.
r? @oli-obk
It's described as a "backwards compatibility hack to keep the diff
small". Removing it requires only a modest amount of churn, and the
resulting code is clearer without the invisible derefs.
Add a compile time check in rustc_lexer and rustc_parse ensuring that unicode-related dependencies within the crate use the same unicode version.
These checks are inspired by the examples privided by @clarfonthey.
```
error[E0308]: mismatched types
--> $DIR/macro-span-caller-replacement.rs:5:17
|
LL | s = format!("{arg}");
| ^^^^^^^^^^^^^^^^ expected `&str`, found `String`
...
LL | macro_with_format!();
| -------------------- in this macro invocation
|
= note: this error originates in the macro `format` which comes from the expansion of the macro `macro_with_format` (in Nightly builds, run with -Z macro-backtrace for more info)
```
The `name()` function specifies that it returns absolute path of items,
however it wasn't including the crate name for local items.
This change fixes that.
This was reported here: https://github.com/rust-lang/project-stable-mir/issues/109
```
error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied
--> $DIR/issue-67185-2.rs:21:6
|
LL | impl Foo for FooImpl {}
| ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]`
|
help: the following other types implement trait `Bar`
--> $DIR/issue-67185-2.rs:9:1
|
LL | impl Bar for [u16; 4] {}
| ^^^^^^^^^^^^^^^^^^^^^ `[u16; 4]`
LL | impl Bar for [[u16; 3]; 3] {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^ `[[u16; 3]; 3]`
note: required by a bound in `Foo`
--> $DIR/issue-67185-2.rs:14:30
|
LL | trait Foo
| --- required by a bound in this trait
LL | where
LL | [<u8 as Baz>::Quaks; 2]: Bar,
| ^^^ required by this bound in `Foo`
```
Previously in the `//`-compiletest-directive times, this was implemented
as a special `no-*` directive parsing. In the migration from `//` ->
`//@`, the `// no-remap-src-base` directive was lost, most likely
because it had no effect -- the default is not remapping `src-base`.
So remove occurrences of `no-remap-src-base`, as these are not valid
directives.
When encountering an unmet trait bound, point at local type that doesn't implement the trait:
```
error[E0277]: the trait bound `Bar<T>: Foo` is not satisfied
--> $DIR/issue-64855.rs:9:19
|
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
| ^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
|
help: the trait `Foo` is not implemented for `Bar<T>`
--> $DIR/issue-64855.rs:9:1
|
LL | pub struct Bar<T>(<Self as Foo>::Type) where Self: ;
| ^^^^^^^^^^^^^^^^^
```
