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Diffstat (limited to '')
-rw-r--r-- | src/tools/clippy/clippy_lints/src/methods/needless_option_take.rs | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/tools/clippy/clippy_lints/src/methods/needless_option_take.rs b/src/tools/clippy/clippy_lints/src/methods/needless_option_take.rs new file mode 100644 index 000000000..829c118d2 --- /dev/null +++ b/src/tools/clippy/clippy_lints/src/methods/needless_option_take.rs @@ -0,0 +1,41 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::match_def_path; +use clippy_utils::source::snippet_with_applicability; +use clippy_utils::ty::is_type_diagnostic_item; +use rustc_errors::Applicability; +use rustc_hir::Expr; +use rustc_lint::LateContext; +use rustc_span::sym; + +use super::NEEDLESS_OPTION_TAKE; + +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, recv: &'tcx Expr<'_>) { + // Checks if expression type is equal to sym::Option and if the expr is not a syntactic place + if !recv.is_syntactic_place_expr() && is_expr_option(cx, recv) && has_expr_as_ref_path(cx, recv) { + let mut applicability = Applicability::MachineApplicable; + span_lint_and_sugg( + cx, + NEEDLESS_OPTION_TAKE, + expr.span, + "called `Option::take()` on a temporary value", + "try", + format!( + "{}", + snippet_with_applicability(cx, recv.span, "..", &mut applicability) + ), + applicability, + ); + } +} + +fn is_expr_option(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { + let expr_type = cx.typeck_results().expr_ty(expr); + is_type_diagnostic_item(cx, expr_type, sym::Option) +} + +fn has_expr_as_ref_path(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool { + if let Some(ref_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id) { + return match_def_path(cx, ref_id, &["core", "option", "Option", "as_ref"]); + } + false +} |