diff options
| -rw-r--r-- | clippy_lints/src/operators/arithmetic_side_effects.rs | 59 | ||||
| -rw-r--r-- | tests/ui/arithmetic_side_effects.rs | 40 | ||||
| -rw-r--r-- | tests/ui/arithmetic_side_effects.stderr | 114 |
3 files changed, 172 insertions, 41 deletions
diff --git a/clippy_lints/src/operators/arithmetic_side_effects.rs b/clippy_lints/src/operators/arithmetic_side_effects.rs index d24c57c0a4b..c8a374d90b5 100644 --- a/clippy_lints/src/operators/arithmetic_side_effects.rs +++ b/clippy_lints/src/operators/arithmetic_side_effects.rs @@ -9,7 +9,6 @@ use rustc_ast as ast; use rustc_data_structures::fx::FxHashSet; use rustc_hir as hir; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty::Ty; use rustc_session::impl_lint_pass; use rustc_span::source_map::{Span, Spanned}; @@ -78,28 +77,47 @@ impl ArithmeticSideEffects { ) } - /// Explicit integers like `1` or `i32::MAX`. Does not take into consideration references. - fn is_literal_integer(expr: &hir::Expr<'_>, expr_refs: Ty<'_>) -> bool { - let is_integral = expr_refs.is_integral(); - let is_literal = matches!(expr.kind, hir::ExprKind::Lit(_)); - is_integral && is_literal - } - + // Common entry-point to avoid code duplication. fn issue_lint(&mut self, cx: &LateContext<'_>, expr: &hir::Expr<'_>) { let msg = "arithmetic operation that can potentially result in unexpected side-effects"; span_lint(cx, ARITHMETIC_SIDE_EFFECTS, expr.span, msg); self.expr_span = Some(expr.span); } + /// * If `expr` is a literal integer like `1` or `i32::MAX`, returns itself. + /// * Is `expr` is a literal integer reference like `&199`, returns the literal integer without + /// references. + /// * If `expr` is anything else, returns `None`. + fn literal_integer<'expr, 'tcx>( + cx: &LateContext<'tcx>, + expr: &'expr hir::Expr<'tcx>, + ) -> Option<&'expr hir::Expr<'tcx>> { + let expr_refs = cx.typeck_results().expr_ty(expr).peel_refs(); + + if !expr_refs.is_integral() { + return None; + } + + if matches!(expr.kind, hir::ExprKind::Lit(_)) { + return Some(expr); + } + + if let hir::ExprKind::AddrOf(.., inn) = expr.kind && let hir::ExprKind::Lit(_) = inn.kind { + return Some(inn) + } + + None + } + /// Manages when the lint should be triggered. Operations in constant environments, hard coded /// types, custom allowed types and non-constant operations that won't overflow are ignored. - fn manage_bin_ops( + fn manage_bin_ops<'tcx>( &mut self, - cx: &LateContext<'_>, - expr: &hir::Expr<'_>, + cx: &LateContext<'tcx>, + expr: &hir::Expr<'tcx>, op: &Spanned<hir::BinOpKind>, - lhs: &hir::Expr<'_>, - rhs: &hir::Expr<'_>, + lhs: &hir::Expr<'tcx>, + rhs: &hir::Expr<'tcx>, ) { if constant_simple(cx, cx.typeck_results(), expr).is_some() { return; @@ -119,14 +137,11 @@ impl ArithmeticSideEffects { if self.is_allowed_ty(cx, lhs) || self.is_allowed_ty(cx, rhs) { return; } - let has_valid_op = match ( - Self::is_literal_integer(lhs, cx.typeck_results().expr_ty(lhs).peel_refs()), - Self::is_literal_integer(rhs, cx.typeck_results().expr_ty(rhs).peel_refs()), - ) { - (true, true) => true, - (true, false) => Self::has_valid_op(op, lhs), - (false, true) => Self::has_valid_op(op, rhs), - (false, false) => false, + let has_valid_op = match (Self::literal_integer(cx, lhs), Self::literal_integer(cx, rhs)) { + (None, None) => false, + (None, Some(local_expr)) => Self::has_valid_op(op, local_expr), + (Some(local_expr), None) => Self::has_valid_op(op, local_expr), + (Some(_), Some(_)) => true, }; if !has_valid_op { self.issue_lint(cx, expr); @@ -135,7 +150,7 @@ impl ArithmeticSideEffects { } impl<'tcx> LateLintPass<'tcx> for ArithmeticSideEffects { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &hir::Expr<'tcx>) { if self.expr_span.is_some() || self.const_span.map_or(false, |sp| sp.contains(expr.span)) { return; } diff --git a/tests/ui/arithmetic_side_effects.rs b/tests/ui/arithmetic_side_effects.rs index dd24f5aa592..6741e148547 100644 --- a/tests/ui/arithmetic_side_effects.rs +++ b/tests/ui/arithmetic_side_effects.rs @@ -2,11 +2,12 @@ clippy::assign_op_pattern, clippy::erasing_op, clippy::identity_op, + clippy::op_ref, clippy::unnecessary_owned_empty_strings, arithmetic_overflow, unconditional_panic )] -#![feature(inline_const, saturating_int_impl)] +#![feature(const_mut_refs, inline_const, saturating_int_impl)] #![warn(clippy::arithmetic_side_effects)] use core::num::{Saturating, Wrapping}; @@ -79,33 +80,50 @@ pub fn const_ops_should_not_trigger_the_lint() { const _: i32 = 1 + 1; let _ = const { 1 + 1 }; - const _: i32 = { let mut n = -1; n = -(-1); n = -n; n }; - let _ = const { let mut n = -1; n = -(-1); n = -n; n }; + const _: i32 = { let mut n = 1; n = -1; n = -(-1); n = -n; n }; + let _ = const { let mut n = 1; n = -1; n = -(-1); n = -n; n }; } -pub fn non_overflowing_runtime_ops_or_ops_already_handled_by_the_compiler() { +pub fn non_overflowing_ops_or_ops_already_handled_by_the_compiler_should_not_trigger_the_lint() { let mut _n = i32::MAX; // Assign _n += 0; + _n += &0; _n -= 0; + _n -= &0; _n /= 99; + _n /= &99; _n %= 99; + _n %= &99; _n *= 0; + _n *= &0; _n *= 1; + _n *= &1; // Binary _n = _n + 0; + _n = _n + &0; _n = 0 + _n; + _n = &0 + _n; _n = _n - 0; + _n = _n - &0; _n = 0 - _n; + _n = &0 - _n; _n = _n / 99; + _n = _n / &99; _n = _n % 99; + _n = _n % &99; _n = _n * 0; + _n = _n * &0; _n = 0 * _n; + _n = &0 * _n; _n = _n * 1; + _n = _n * &1; _n = 1 * _n; + _n = &1 * _n; _n = 23 + 85; + _n = &23 + &85; // Unary _n = -1; @@ -117,23 +135,37 @@ pub fn overflowing_runtime_ops() { // Assign _n += 1; + _n += &1; _n -= 1; + _n -= &1; _n /= 0; + _n /= &0; _n %= 0; + _n %= &0; _n *= 2; + _n *= &2; // Binary _n = _n + 1; + _n = _n + &1; _n = 1 + _n; + _n = &1 + _n; _n = _n - 1; + _n = _n - &1; _n = 1 - _n; + _n = &1 - _n; _n = _n / 0; + _n = _n / &0; _n = _n % 0; + _n = _n % &0; _n = _n * 2; + _n = _n * &2; _n = 2 * _n; + _n = &2 * _n; // Unary _n = -_n; + _n = -&_n; } fn main() {} diff --git a/tests/ui/arithmetic_side_effects.stderr b/tests/ui/arithmetic_side_effects.stderr index a2a856efbff..4dce13b624b 100644 --- a/tests/ui/arithmetic_side_effects.stderr +++ b/tests/ui/arithmetic_side_effects.stderr @@ -1,5 +1,5 @@ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:119:5 + --> $DIR/arithmetic_side_effects.rs:137:5 | LL | _n += 1; | ^^^^^^^ @@ -7,82 +7,166 @@ LL | _n += 1; = note: `-D clippy::arithmetic-side-effects` implied by `-D warnings` error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:120:5 + --> $DIR/arithmetic_side_effects.rs:138:5 + | +LL | _n += &1; + | ^^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:139:5 | LL | _n -= 1; | ^^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:121:5 + --> $DIR/arithmetic_side_effects.rs:140:5 + | +LL | _n -= &1; + | ^^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:141:5 | LL | _n /= 0; | ^^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:122:5 + --> $DIR/arithmetic_side_effects.rs:142:5 + | +LL | _n /= &0; + | ^^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:143:5 | LL | _n %= 0; | ^^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:123:5 + --> $DIR/arithmetic_side_effects.rs:144:5 + | +LL | _n %= &0; + | ^^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:145:5 | LL | _n *= 2; | ^^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:126:10 + --> $DIR/arithmetic_side_effects.rs:146:5 + | +LL | _n *= &2; + | ^^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:149:10 | LL | _n = _n + 1; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:127:10 + --> $DIR/arithmetic_side_effects.rs:150:10 + | +LL | _n = _n + &1; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:151:10 | LL | _n = 1 + _n; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:128:10 + --> $DIR/arithmetic_side_effects.rs:152:10 + | +LL | _n = &1 + _n; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:153:10 | LL | _n = _n - 1; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:129:10 + --> $DIR/arithmetic_side_effects.rs:154:10 + | +LL | _n = _n - &1; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:155:10 | LL | _n = 1 - _n; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:130:10 + --> $DIR/arithmetic_side_effects.rs:156:10 + | +LL | _n = &1 - _n; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:157:10 | LL | _n = _n / 0; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:131:10 + --> $DIR/arithmetic_side_effects.rs:158:10 + | +LL | _n = _n / &0; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:159:10 | LL | _n = _n % 0; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:132:10 + --> $DIR/arithmetic_side_effects.rs:160:10 + | +LL | _n = _n % &0; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:161:10 | LL | _n = _n * 2; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:133:10 + --> $DIR/arithmetic_side_effects.rs:162:10 + | +LL | _n = _n * &2; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:163:10 | LL | _n = 2 * _n; | ^^^^^^ error: arithmetic operation that can potentially result in unexpected side-effects - --> $DIR/arithmetic_side_effects.rs:136:10 + --> $DIR/arithmetic_side_effects.rs:164:10 + | +LL | _n = &2 * _n; + | ^^^^^^^ + +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:167:10 | LL | _n = -_n; | ^^^ -error: aborting due to 14 previous errors +error: arithmetic operation that can potentially result in unexpected side-effects + --> $DIR/arithmetic_side_effects.rs:168:10 + | +LL | _n = -&_n; + | ^^^^ + +error: aborting due to 28 previous errors |