How to contribute to Rust and what I have recently been working on

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1. How to contribute to Rust and what
   I have recently been working on
   Takayuki Maeda (@TaKO8Ki)
   

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2. About myself
   

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3. About myself
   Takayuki Maeda at CTO Office
   GitHub: @TaKO8Ki
   Twitter: @TaKOBKi
   Pull requests I created in rust-lang/rust
   

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4. How to contribute to Rust
   All we want is "Guide to Rustc Development".
   

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5. Guide to Rustc Development
   Building and debugging rustc
   Contributing to rustc
   High-Level Compiler Architecture
   Source Code Representation
   Analysis
   From MIR to Binaries
   Appendices
   has seven parts:
   1.
   2.
   3.
   4.
   5.
   6.
   7.
   

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6. Guide to Rustc Development
   Building and debugging rustc
   Contributing to rustc
   High-Level Compiler Architecture
   Source Code Representation
   Analysis
   From MIR to Binaries
   Appendices
   has seven parts:
   1.
   2.
   3.
   4.
   5.
   6.
   7.
   

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7. $ git clone https://github.com/rust-lang/rust.git
   $ cd rust
   Building rustc – the Rust compiler –
   rustc is a bootstrapping compiler
   $ ./x.py setup
   

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8. Building rustc – the Rust compiler –
   Choose the one you want to contribute to
   

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9. Building rustc – the Rust compiler –
   ./x.py setup creates config.toml
   [rust]
   debug-logging = true # Leave debug! and trace! calls
   in rustc?
   incremental = true # Build rustc with
   incremental compilation?
   

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10. Building rustc – the Rust compiler –
    Build a compiler
    $ ./x.py build
    If you want to use incremental compilation
    $ ./x.py build -i library/std
    

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11. Building rustc – the Rust compiler –
    Build std using the stage0 compiler (using incremental)
    Build rustc using the stage0 compiler (using incremental)
    This produces the stage1 compiler
    Build std using the stage1 compiler (cannot use
    incremental)
    This command does the following things:
    $ ./x.py build -i library/std
    

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12. Building rustc – the Rust compiler –
    You cannot use incremental compilation for stage1
    libraries.This is because incremental only works when you
    run the same compiler twice in a row.
    

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13. Building rustc – the Rust compiler –
    $ rustup toolchain link stage1 build/triple>/stage1
    Create rustup toolchains
    Then you can run
    $ rustc +stage1 -vV
    $ cargo +stage1 build
    

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14. Testing rustc
    $ ./x.py test src/test/ui
    If you want to run rustc ui tests
    If you want to run specific tests
    $ ./x.py test src/test/ui --test-args 'derives'
    

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15. Debugging rustc
    rustc uses tokio/tracing for logging.
    

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16. Debugging rustc
    debug!("lower_opaque_impl_trait: lifetime_defs=
    {:#?}", lifetime_defs);
    debug!(?lifetime_defs);
    or
    

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17. Debugging rustc
    $ RUSTC_LOG=rustc_middle::traits=debug cargo +stage1
    build
    You can use module level filters
    You can use the other filters such as function level filters and
    query level filters.
    

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18. Debugging rustc
    #[instrument(level = "debug", skip(self))]
    fn foo(&self, bar: Type) {}
    Function level filters
    

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19. Find issues
    If you are interested in developing a parser
    → A-parser (Area: The parsing of Rust source code to
    an AST.)
    If you are interested in developing a rustdoc
    → T-rustdoc (Relevant to the rustdoc Team, which will
    review and decide on the PR/issue.)
    https://github.com/rust-lang/rust/issues
    There are some labels like the following:
    

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20. If you have any questions
    The best way to get started is by asking for help in the #new
    members Zulip stream.
    

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21. Issue #98087
    

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22. macro_rules! foo {
    () => {};
    }
    pub use foo;
    Given the following code:
    Issue #98087
    

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23. Issue #98087
    The current output is:
    rustc suggests adding a macro `pub`
    

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24. Issue #98087
    The current output is:
    However, you need to use `#
    [macro_export]` to make the macro public.
    

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25. Issue #98087
    Suggest using `#[macro_export]` when binding.kind is
    `NameBindingKind::Res(Res::Def(DefKind::Macro(_),
    _def_id), _)`
    

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26. Issue #98087
    However, this suggestion is triggered also by
    decl_macro.
    

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27. Issue #98087
    To solve this problem, I implemented struct `MacroData` including
    a flag for checking if a macro is `decl_macro` or not.
    

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28. Issue #98087
    And change the type of HashMap `macro_map` value to
    `MacroData`.
    

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29. Issue #98087
    Exclude decl_macros
    

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30. Issue #98087
    Add a ui test
    

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31. Issue #98087
    Add a ui test
    

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32. Issue #98087
    Create a pull request
    

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33. Issue #98087
    Approved 🚀🚀🚀
    

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