Add info message for -Wall command #48765
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Users coming from other languages (namely C and C++) often expect to use a -Wall flag. Rustc doesn't support that, and previously it simply printed that it didn't recognize the "all" lint. This change makes rustc print out a help message, explaining: - Why there is no -Wall flag - How to view all the available warnings - Point out that the most commonly used warning is -Wunused - Instead of using a command-line flag, the user should consider a !#[warn(unused)] directive in the root of their crate.
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Failed tidy. |
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Not sure who to assign this to... maybe r? @estebank |
src/librustc_driver/lib.rs
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| Use `rustc -W help` to see all available lints. The most used lints that are not | ||
| enabled by default covered by -Wunused; however, the best practice is to put | ||
| warning settings in the crate root using `#![warn(unused)]` instead of using | ||
| the command line flag directly. |
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I'm fine with the feature. I would like to have a native speaker take a look over this. cc @rust-lang/docs
Maybe something closer to:
The flag `-Wall` does not exist in `rustc`. Most useful lints are enabled by default.
Use `rustc -W help` to see all available lints. The most used lints that are not
enabled by default are covered by `-Wunused`; however, the best practice is to
put warning settings in the crate root using `#![warn(LINT_NAME)]` instead of using
the command line flag directly.
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The most used lints that are not enabled by default are covered by
-Wunused
Is there any particular reason why -Wunused is being called out here? Why unused vs. other lint checks?
the best practice is to put warning settings...
I might say "it's more common to put warning settings...", but I don't feel strongly
Other than that, seems good to me 👍
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unused turns on half of the allowed-by-default lints that I've ever seen used:
unused-qualificationsunused-resultsunused-import-bracesunused-extern-crates
The others that I've personally seen used are:
missing-docstrivial-caststrivial-numeric-castsunreachable-pub
And given that a LOT of crates in the ecosystem have #![warn(unused)], I thought it was the most relevant one to mention.
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Actually, looking at the -W help output, -Wunused only turns on unused-extern-crates... I thought it did all the unused-* lints?
I might have to go step-up my #![warn(unused-*)] lines in my projects.
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Actually, looking at the
-W helpoutput,-Wunusedonly turns onunused-extern-crates
taken from rustc -W help
Lint groups provided by rustc:
name sub-lints
---- ---------
warnings all lints that are set to issue warnings
bad-style non-camel-case-types, non-snake-case, non-upper-case-globals
future-incompatible private-in-public, pub-use-of-private-extern-crate, patterns-in-fns-without-body, safe-extern-statics, invalid-type-param-default, legacy-directory-ownership, legacy-imports, legacy-constructor-visibility, resolve-trait-on-defaulted-unit, missing-fragment-specifier, illegal-floating-point-literal-pattern, anonymous-parameters, parenthesized-params-in-types-and-modules, late-bound-lifetime-arguments, safe-packed-borrows, incoherent-fundamental-impls, coerce-never, tyvar-behind-raw-pointer
unused unused-imports, unused-variables, unused-assignments, dead-code, unused-mut, unreachable-code, unreachable-patterns, unused-must-use, unused-unsafe, path-statements, unused-attributes, unused-macros, unused-allocation, unused-doc-comment, unused-extern-crates, unused-features, unused-parens
Compiler plugins can provide additional lints and lint groups. To see a listing of these, re-run `rustc -W help` with a crate filename.
The reference to -Wunused was removed, and some phrasing was changed.
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@bors r+ rollup |
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📌 Commit c1337cd has been approved by |
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…, r=estebank Add info message for -Wall command Users coming from other languages (namely C and C++) often expect to use a -Wall flag. Rustc doesn't support that, and previously it simply printed that it didn't recognize the "all" lint. This change makes rustc print out a help message, explaining: - Why there is no -Wall flag - How to view all the available warnings - Point out that the most commonly used warning is -Wunused - Instead of using a command-line flag, the user should consider a !#[warn(unused)] directive in the root of their crate. I tried to keep the language consistent with the other usage help. Comment if I should change anything. closes rust-lang#10234, if accepted.
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Might be worth it to mention |
Users coming from other languages (namely C and C++) often expect
to use a -Wall flag. Rustc doesn't support that, and previously it
simply printed that it didn't recognize the "all" lint.
This change makes rustc print out a help message, explaining:
a !#[warn(unused)] directive in the root of their crate.
I tried to keep the language consistent with the other usage help. Comment if I should change anything.
closes #10234, if accepted.