Remove #[main] attribute. #84217
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Remove #[main] attribute. #84217
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| Some changes occurred in src/tools/clippy. cc @rust-lang/clippy |
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rust-highfive added a commit to rust-lang-nursery/rust-toolstate that referenced this pull request Apr 16, 2021
Tested on commit rust-lang/rust@d4bc912. Direct link to PR: <rust-lang/rust#84217> 💔 miri on windows: test-pass → test-fail (cc @oli-obk @RalfJung @eddyb). 💔 miri on linux: test-pass → test-fail (cc @oli-obk @RalfJung @eddyb).
This was referenced Feb 8, 2022
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Feb 9, 2022
…henkov Complete removal of #[main] attribute from compiler resolves rust-lang#93786 --- The `#[main]` attribute was mostly removed from the language in rust-lang#84217, but not completely. It is still recognized as a builtin attribute by the compiler, but it has no effect. However, this no-op attribute is no longer gated by `#[feature(main)]` (which no longer exists), so it's possible to include it in code *on stable* without any errors, which seems unintentional. For example, the following code is accepted ([playground link](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&code=%23%5Bmain%5D%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22hello%20world%22)%3B%0A%7D%0A)). ```rust #[main] fn main() { println!("hello world"); } ``` Aside from that oddity, the existence of this attribute causes code like the following to fail ([playground link](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&code=use%20tokio%3A%3Amain%3B%0A%0A%23%5Bmain%5D%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22hello%20world%22)%3B%0A%7D%0A)). According rust-lang#84062 (comment), the removal of `#[main]` was expected to eliminate this conflict (previously reported as rust-lang#62127). ```rust use tokio::main; #[main] fn main() { println!("hello world"); } ``` ``` error[E0659]: `main` is ambiguous --> src/main.rs:3:3 | 3 | #[main] | ^^^^ ambiguous name | = note: ambiguous because of a name conflict with a builtin attribute = note: `main` could refer to a built-in attribute ``` [This error message can be confusing](https://stackoverflow.com/q/71024443/1114), as the mostly-removed `#[main]` attribute is not mentioned in any documentation. Since the current availability of `#[main]` on stable seems unintentional, and to needlessly block use of the `main` identifier in the attribute namespace, this PR finishes removing the `#[main]` attribute as described in rust-lang#29634 (comment) by deleting it from `builtin_attrs.rs`, and adds two test cases to ensure that the attribute is no longer accepted and no longer conflicts with other attributes imported as `main`.
matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Feb 9, 2022
…henkov Complete removal of #[main] attribute from compiler resolves rust-lang#93786 --- The `#[main]` attribute was mostly removed from the language in rust-lang#84217, but not completely. It is still recognized as a builtin attribute by the compiler, but it has no effect. However, this no-op attribute is no longer gated by `#[feature(main)]` (which no longer exists), so it's possible to include it in code *on stable* without any errors, which seems unintentional. For example, the following code is accepted ([playground link](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&code=%23%5Bmain%5D%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22hello%20world%22)%3B%0A%7D%0A)). ```rust #[main] fn main() { println!("hello world"); } ``` Aside from that oddity, the existence of this attribute causes code like the following to fail ([playground link](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&code=use%20tokio%3A%3Amain%3B%0A%0A%23%5Bmain%5D%0Afn%20main()%20%7B%0A%20%20%20%20println!(%22hello%20world%22)%3B%0A%7D%0A)). According rust-lang#84062 (comment), the removal of `#[main]` was expected to eliminate this conflict (previously reported as rust-lang#62127). ```rust use tokio::main; #[main] fn main() { println!("hello world"); } ``` ``` error[E0659]: `main` is ambiguous --> src/main.rs:3:3 | 3 | #[main] | ^^^^ ambiguous name | = note: ambiguous because of a name conflict with a builtin attribute = note: `main` could refer to a built-in attribute ``` [This error message can be confusing](https://stackoverflow.com/q/71024443/1114), as the mostly-removed `#[main]` attribute is not mentioned in any documentation. Since the current availability of `#[main]` on stable seems unintentional, and to needlessly block use of the `main` identifier in the attribute namespace, this PR finishes removing the `#[main]` attribute as described in rust-lang#29634 (comment) by deleting it from `builtin_attrs.rs`, and adds two test cases to ensure that the attribute is no longer accepted and no longer conflicts with other attributes imported as `main`.
JohnTitor added a commit to JohnTitor/rust that referenced this pull request Jun 24, 2022
…=petrochenkov Fixup missing renames from `#[main]` to `#[rustc_main]` In rust-lang#84217 `#[main]` was removed and replaced with `#[rustc_main]`. In some places the rename was forgotten, which makes the current code confusing, because at first glance it seems that `#[main]` is still around. Perform the renames also in these places. I noticed this (after first being confused by it) when working on rust-lang#97802. r? `@petrochenkov` (since you reviewed the other PR)
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This removes the #[main] attribute support from the compiler according to the decisions within #29634. For existing use cases within test harness generation, replaced it with a newly-introduced internal attribute
#[rustc_main].This is first part extracted from #84062 .
Closes #29634.
r? @petrochenkov