From 503fd56a423c8da7958aa3fc611b623270d02fde Mon Sep 17 00:00:00 2001 From: timvisee Date: Mon, 17 Apr 2023 20:25:42 +0200 Subject: [PATCH] Suggest applicable expression for manual slice size calculation lint --- .../src/manual_slice_size_calculation.rs | 22 ++++++++++++------ tests/ui/manual_slice_size_calculation.stderr | 23 +++++-------------- 2 files changed, 21 insertions(+), 24 deletions(-) diff --git a/clippy_lints/src/manual_slice_size_calculation.rs b/clippy_lints/src/manual_slice_size_calculation.rs index ba01fd08530..cef5b8361a4 100644 --- a/clippy_lints/src/manual_slice_size_calculation.rs +++ b/clippy_lints/src/manual_slice_size_calculation.rs @@ -1,5 +1,7 @@ -use clippy_utils::diagnostics::span_lint_and_help; +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::source::snippet_with_context; use clippy_utils::{expr_or_init, in_constant}; +use rustc_errors::Applicability; use rustc_hir::{BinOpKind, Expr, ExprKind}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty; @@ -42,15 +44,21 @@ impl<'tcx> LateLintPass<'tcx> for ManualSliceSizeCalculation { if !in_constant(cx, expr.hir_id) && let ExprKind::Binary(ref op, left, right) = expr.kind && BinOpKind::Mul == op.node - && let Some(_receiver) = simplify(cx, left, right) + && let Some(receiver) = simplify(cx, left, right) { - span_lint_and_help( + let ctxt = expr.span.ctxt(); + let mut app = Applicability::MachineApplicable; + let val_name = snippet_with_context(cx, receiver.span, ctxt, "slice", &mut app).0; + + span_lint_and_sugg( cx, MANUAL_SLICE_SIZE_CALCULATION, - expr.span, - "manual slice size calculation", - None, - "consider using std::mem::size_of_val instead"); + expr.span, + "manual slice size calculation", + "try", + format!("std::mem::size_of_val({val_name})"), + Applicability::MachineApplicable, + ); } } } diff --git a/tests/ui/manual_slice_size_calculation.stderr b/tests/ui/manual_slice_size_calculation.stderr index 7698d9782f0..b88f523ddcf 100644 --- a/tests/ui/manual_slice_size_calculation.stderr +++ b/tests/ui/manual_slice_size_calculation.stderr @@ -2,50 +2,39 @@ error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:11:13 | LL | let _ = s_i32.len() * size_of::(); // WARNING - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` | - = help: consider using std::mem::size_of_val instead = note: `-D clippy::manual-slice-size-calculation` implied by `-D warnings` error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:12:13 | LL | let _ = size_of::() * s_i32.len(); // WARNING - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | - = help: consider using std::mem::size_of_val instead + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:13:13 | LL | let _ = size_of::() * s_i32.len() * 5; // WARNING - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | - = help: consider using std::mem::size_of_val instead + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:17:13 | LL | let _ = len * size_of::(); // WARNING - | ^^^^^^^^^^^^^^^^^^^^^^ - | - = help: consider using std::mem::size_of_val instead + | ^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:18:13 | LL | let _ = s_i32.len() * size; // WARNING - | ^^^^^^^^^^^^^^^^^^ - | - = help: consider using std::mem::size_of_val instead + | ^^^^^^^^^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` error: manual slice size calculation --> $DIR/manual_slice_size_calculation.rs:19:13 | LL | let _ = len * size; // WARNING - | ^^^^^^^^^^ - | - = help: consider using std::mem::size_of_val instead + | ^^^^^^^^^^ help: try: `std::mem::size_of_val(s_i32)` error: aborting due to 6 previous errors