45 lines
1.2 KiB
Rust
45 lines
1.2 KiB
Rust
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use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
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use rustc_front::hir::{Expr, ExprAssign, ExprField, ExprStruct, ExprTup, ExprTupField};
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use utils::is_adjusted;
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use utils::span_lint;
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declare_lint! {
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pub TEMPORARY_ASSIGNMENT,
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Warn,
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"assignments to temporaries"
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}
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fn is_temporary(expr: &Expr) -> bool {
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match expr.node {
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ExprStruct(..) |
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ExprTup(..) => true,
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_ => false,
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}
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}
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#[derive(Copy, Clone)]
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pub struct TemporaryAssignmentPass;
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impl LintPass for TemporaryAssignmentPass {
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fn get_lints(&self) -> LintArray {
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lint_array!(TEMPORARY_ASSIGNMENT)
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}
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}
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impl LateLintPass for TemporaryAssignmentPass {
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fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
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if let ExprAssign(ref target, _) = expr.node {
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match target.node {
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ExprField(ref base, _) | ExprTupField(ref base, _) => {
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if is_temporary(base) && !is_adjusted(cx, base) {
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span_lint(cx, TEMPORARY_ASSIGNMENT, expr.span,
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"assignment to temporary");
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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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}
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