Avoid unused braces lint for macro generated arguments#158791
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Avoid unused braces lint for macro generated arguments#158791chenyukang wants to merge 1 commit into
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r? @folkertdev rustbot has assigned @folkertdev. Use Why was this reviewer chosen?The reviewer was selected based on:
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| for arg in args_to_check { | ||
| if callee_from_expansion && Self::block_wraps_expanded_expr(arg) { | ||
| continue; | ||
| } |
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this deserves a comment
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Maybe
Whether an expression is wrapped in a block can change what arm of a
macro_rules!is taken. Don't report the braces as unused that might be the case.
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| fn block_wraps_expanded_expr(value: &ast::Expr) -> bool { |
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probably could use a comment too
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| //@ check-pass | |||
| //@ run-rustfix | |||
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these days we often like to put a one-sentence description of what this is testing and why at the top of these files
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Lovely, thanks! @bors r+ rollup |
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…d-braces-macro, r=folkertdev Avoid unused braces lint for macro generated arguments Fixes rust-lang#158747 This changes the `unused_braces` lint to avoid suggesting brace removal for macro arguments when those braces may affect `macro_rules!`. But the fragment kind matters: - `$e:expr` matches an expression. Both `1` and `{ 1 }` are expressions, so removing braces can still leave the macro matching the same kind of input. - `$b:block` only matches a block expression written with braces. `{ 1 }` matches, but `1` does not. So `call_expr!({ 1 })` can usually be simplified to `call_expr!(1)`, while `call_block!({ 1 })` cannot. It seems a more concrect report need a full `macro_rules!` matcher analysis, that seems too heavy for `unused` lint.
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…d-braces-macro, r=folkertdev Avoid unused braces lint for macro generated arguments Fixes rust-lang#158747 This changes the `unused_braces` lint to avoid suggesting brace removal for macro arguments when those braces may affect `macro_rules!`. But the fragment kind matters: - `$e:expr` matches an expression. Both `1` and `{ 1 }` are expressions, so removing braces can still leave the macro matching the same kind of input. - `$b:block` only matches a block expression written with braces. `{ 1 }` matches, but `1` does not. So `call_expr!({ 1 })` can usually be simplified to `call_expr!(1)`, while `call_block!({ 1 })` cannot. It seems a more concrect report need a full `macro_rules!` matcher analysis, that seems too heavy for `unused` lint.
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Fixes #158747
This changes the
unused_braceslint to avoid suggesting brace removal for macro arguments when those braces may affectmacro_rules!.But the fragment kind matters:
$e:exprmatches an expression. Both1and{ 1 }are expressions, so removing braces can still leave the macro matching the same kind of input.$b:blockonly matches a block expression written with braces.{ 1 }matches, but1does not.So
call_expr!({ 1 })can usually be simplified tocall_expr!(1), whilecall_block!({ 1 })cannot.It seems a more concrect report need a full
macro_rules!matcher analysis, that seems too heavy forunusedlint.