64 lines
1.8 KiB
Rust
64 lines
1.8 KiB
Rust
use rustc::lint::*;
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use rustc::hir::*;
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use utils::{in_macro, is_range_expression, match_var, span_lint_and_sugg};
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/// **What it does:** Checks for fields in struct literals where shorthands
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/// could be used.
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///
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/// **Why is this bad?** If the field and variable names are the same,
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/// the field name is redundant.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let bar: u8 = 123;
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///
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/// struct Foo {
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/// bar: u8,
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/// }
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///
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/// let foo = Foo{ bar: bar }
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/// ```
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declare_lint! {
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pub REDUNDANT_FIELD_NAMES,
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Warn,
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"checks for fields in struct literals where shorthands could be used"
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}
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pub struct RedundantFieldNames;
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impl LintPass for RedundantFieldNames {
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fn get_lints(&self) -> LintArray {
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lint_array!(REDUNDANT_FIELD_NAMES)
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}
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}
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for RedundantFieldNames {
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fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
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// Ignore all macros including range expressions.
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// They can have redundant field names when expanded.
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// e.g. range expression `start..end` is desugared to `Range { start: start, end: end }`
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if in_macro(expr.span) || is_range_expression(expr.span) {
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return;
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}
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if let ExprStruct(_, ref fields, _) = expr.node {
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for field in fields {
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let name = field.name.node;
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if match_var(&field.expr, name) && !field.is_shorthand {
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span_lint_and_sugg (
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cx,
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REDUNDANT_FIELD_NAMES,
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field.span,
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"redundant field names in struct initialization",
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"replace it with",
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name.to_string()
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);
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}
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}
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}
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}
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}
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