[arithmetic-side-effects] Detect overflowing associated constants of integers

This commit is contained in:
Caio 2022-11-19 08:22:27 -03:00
parent d15e5e6ad6
commit 98b343c5e6
4 changed files with 130 additions and 114 deletions

View file

@ -1,12 +1,19 @@
use super::ARITHMETIC_SIDE_EFFECTS;
use clippy_utils::{consts::constant_simple, diagnostics::span_lint};
use clippy_utils::{
consts::{constant, constant_simple},
diagnostics::span_lint,
peel_hir_expr_refs,
};
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};
use rustc_span::{
source_map::{Span, Spanned},
sym,
};
const HARD_CODED_ALLOWED: &[&str] = &[
"&str",
@ -38,24 +45,6 @@ impl ArithmeticSideEffects {
}
}
/// Assuming that `expr` is a literal integer, checks operators (+=, -=, *, /) in a
/// non-constant environment that won't overflow.
fn has_valid_op(op: &Spanned<hir::BinOpKind>, expr: &hir::Expr<'_>) -> bool {
if let hir::ExprKind::Lit(ref lit) = expr.kind &&
let ast::LitKind::Int(value, _) = lit.node
{
match (&op.node, value) {
(hir::BinOpKind::Div | hir::BinOpKind::Rem, 0) => false,
(hir::BinOpKind::Add | hir::BinOpKind::Sub, 0)
| (hir::BinOpKind::Div | hir::BinOpKind::Rem, _)
| (hir::BinOpKind::Mul, 0 | 1) => true,
_ => false,
}
} else {
false
}
}
/// Checks if the given `expr` has any of the inner `allowed` elements.
fn is_allowed_ty(&self, ty: Ty<'_>) -> bool {
self.allowed
@ -74,15 +63,14 @@ impl ArithmeticSideEffects {
self.expr_span = Some(expr.span);
}
/// If `expr` does not match any variant of `LiteralIntegerTy`, returns `None`.
fn literal_integer<'expr, 'tcx>(expr: &'expr hir::Expr<'tcx>) -> Option<LiteralIntegerTy<'expr, 'tcx>> {
if matches!(expr.kind, hir::ExprKind::Lit(_)) {
return Some(LiteralIntegerTy::Value(expr));
/// If `expr` is not a literal integer like `1`, returns `None`.
fn literal_integer(expr: &hir::Expr<'_>) -> Option<u128> {
if let hir::ExprKind::Lit(ref lit) = expr.kind && let ast::LitKind::Int(n, _) = lit.node {
Some(n)
}
if let hir::ExprKind::AddrOf(.., inn) = expr.kind && let hir::ExprKind::Lit(_) = inn.kind {
return Some(LiteralIntegerTy::Ref(inn));
else {
None
}
None
}
/// Manages when the lint should be triggered. Operations in constant environments, hard coded
@ -117,10 +105,20 @@ impl ArithmeticSideEffects {
return;
}
let has_valid_op = if Self::is_integral(lhs_ty) && Self::is_integral(rhs_ty) {
match (Self::literal_integer(lhs), Self::literal_integer(rhs)) {
(None, Some(lit_int_ty)) | (Some(lit_int_ty), None) => Self::has_valid_op(op, lit_int_ty.into()),
(Some(LiteralIntegerTy::Value(_)), Some(LiteralIntegerTy::Value(_))) => true,
(None, None) | (Some(_), Some(_)) => false,
let (actual_lhs, lhs_ref_counter) = peel_hir_expr_refs(lhs);
let (actual_rhs, rhs_ref_counter) = peel_hir_expr_refs(rhs);
match (Self::literal_integer(actual_lhs), Self::literal_integer(actual_rhs)) {
(None, None) => false,
(None, Some(n)) | (Some(n), None) => match (&op.node, n) {
(hir::BinOpKind::Div | hir::BinOpKind::Rem, 0) => false,
(hir::BinOpKind::Add | hir::BinOpKind::Sub, 0)
| (hir::BinOpKind::Div | hir::BinOpKind::Rem, _)
| (hir::BinOpKind::Mul, 0 | 1) => true,
_ => false,
},
(Some(_), Some(_)) => {
matches!((lhs_ref_counter, rhs_ref_counter), (0, 0))
},
}
} else {
false
@ -129,21 +127,45 @@ impl ArithmeticSideEffects {
self.issue_lint(cx, expr);
}
}
fn manage_unary_ops<'tcx>(
&mut self,
cx: &LateContext<'tcx>,
expr: &hir::Expr<'tcx>,
un_expr: &hir::Expr<'tcx>,
un_op: hir::UnOp,
) {
let hir::UnOp::Neg = un_op else { return; };
if constant(cx, cx.typeck_results(), un_expr).is_some() {
return;
}
let ty = cx.typeck_results().expr_ty(expr).peel_refs();
if self.is_allowed_ty(ty) {
return;
}
let actual_un_expr = peel_hir_expr_refs(un_expr).0;
if Self::literal_integer(actual_un_expr).is_some() {
return;
}
self.issue_lint(cx, expr);
}
fn should_skip_expr(&mut self, expr: &hir::Expr<'_>) -> bool {
self.expr_span.is_some() || self.const_span.map_or(false, |sp| sp.contains(expr.span))
}
}
impl<'tcx> LateLintPass<'tcx> for ArithmeticSideEffects {
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)) {
if self.should_skip_expr(expr) {
return;
}
match &expr.kind {
hir::ExprKind::Binary(op, lhs, rhs) | hir::ExprKind::AssignOp(op, lhs, rhs) => {
hir::ExprKind::AssignOp(op, lhs, rhs) | hir::ExprKind::Binary(op, lhs, rhs) => {
self.manage_bin_ops(cx, expr, op, lhs, rhs);
},
hir::ExprKind::Unary(hir::UnOp::Neg, _) => {
if constant_simple(cx, cx.typeck_results(), expr).is_none() {
self.issue_lint(cx, expr);
}
hir::ExprKind::Unary(un_op, un_expr) => {
self.manage_unary_ops(cx, expr, un_expr, *un_op);
},
_ => {},
}
@ -177,22 +199,3 @@ impl<'tcx> LateLintPass<'tcx> for ArithmeticSideEffects {
}
}
}
/// Tells if an expression is a integer declared by value or by reference.
///
/// If `LiteralIntegerTy::Ref`, then the contained value will be `hir::ExprKind::Lit` rather
/// than `hirExprKind::Addr`.
enum LiteralIntegerTy<'expr, 'tcx> {
/// For example, `&199`
Ref(&'expr hir::Expr<'tcx>),
/// For example, `1` or `i32::MAX`
Value(&'expr hir::Expr<'tcx>),
}
impl<'expr, 'tcx> From<LiteralIntegerTy<'expr, 'tcx>> for &'expr hir::Expr<'tcx> {
fn from(from: LiteralIntegerTy<'expr, 'tcx>) -> Self {
match from {
LiteralIntegerTy::Ref(elem) | LiteralIntegerTy::Value(elem) => elem,
}
}
}

View file

@ -1,6 +1,6 @@
#![warn(clippy::arithmetic_side_effects)]
use core::ops::Add;
use core::ops::{Add, Neg};
#[derive(Clone, Copy)]
struct Point {
@ -16,9 +16,18 @@ impl Add for Point {
}
}
impl Neg for Point {
type Output = Self;
fn neg(self) -> Self::Output {
todo!()
}
}
fn main() {
let _ = Point { x: 1, y: 0 } + Point { x: 2, y: 3 };
let point: Point = Point { x: 1, y: 0 };
let _ = point + point;
let _ = -point;
}

View file

@ -150,8 +150,12 @@ pub fn non_overflowing_ops_or_ops_already_handled_by_the_compiler_should_not_tri
_n = 23 + 85;
// Unary
_n = -1;
_n = -(-1);
_n = -2147483647;
_n = -i32::MAX;
_n = -i32::MIN;
_n = -&2147483647;
_n = -&i32::MAX;
_n = -&i32::MIN;
}
pub fn runtime_ops() {

View file

@ -19,331 +19,331 @@ LL | let _ = inferred_string + "";
| ^^^^^^^^^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:161:5
--> $DIR/arithmetic_side_effects.rs:165:5
|
LL | _n += 1;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:162:5
--> $DIR/arithmetic_side_effects.rs:166:5
|
LL | _n += &1;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:163:5
--> $DIR/arithmetic_side_effects.rs:167:5
|
LL | _n -= 1;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:164:5
--> $DIR/arithmetic_side_effects.rs:168:5
|
LL | _n -= &1;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:165:5
--> $DIR/arithmetic_side_effects.rs:169:5
|
LL | _n /= 0;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:166:5
--> $DIR/arithmetic_side_effects.rs:170:5
|
LL | _n /= &0;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:167:5
--> $DIR/arithmetic_side_effects.rs:171:5
|
LL | _n %= 0;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:168:5
--> $DIR/arithmetic_side_effects.rs:172:5
|
LL | _n %= &0;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:169:5
--> $DIR/arithmetic_side_effects.rs:173:5
|
LL | _n *= 2;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:170:5
--> $DIR/arithmetic_side_effects.rs:174:5
|
LL | _n *= &2;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:173:10
--> $DIR/arithmetic_side_effects.rs:177:10
|
LL | _n = _n + 1;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:174:10
--> $DIR/arithmetic_side_effects.rs:178:10
|
LL | _n = _n + &1;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:175:10
--> $DIR/arithmetic_side_effects.rs:179:10
|
LL | _n = 1 + _n;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:176:10
--> $DIR/arithmetic_side_effects.rs:180:10
|
LL | _n = &1 + _n;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:177:10
--> $DIR/arithmetic_side_effects.rs:181:10
|
LL | _n = _n - 1;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:178:10
--> $DIR/arithmetic_side_effects.rs:182:10
|
LL | _n = _n - &1;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:179:10
--> $DIR/arithmetic_side_effects.rs:183:10
|
LL | _n = 1 - _n;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:180:10
--> $DIR/arithmetic_side_effects.rs:184:10
|
LL | _n = &1 - _n;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:181:10
--> $DIR/arithmetic_side_effects.rs:185:10
|
LL | _n = _n / 0;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:182:10
--> $DIR/arithmetic_side_effects.rs:186:10
|
LL | _n = _n / &0;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:183:10
--> $DIR/arithmetic_side_effects.rs:187:10
|
LL | _n = _n % 0;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:184:10
--> $DIR/arithmetic_side_effects.rs:188:10
|
LL | _n = _n % &0;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:185:10
--> $DIR/arithmetic_side_effects.rs:189:10
|
LL | _n = _n * 2;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:186:10
--> $DIR/arithmetic_side_effects.rs:190:10
|
LL | _n = _n * &2;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:187:10
--> $DIR/arithmetic_side_effects.rs:191:10
|
LL | _n = 2 * _n;
| ^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:188:10
--> $DIR/arithmetic_side_effects.rs:192:10
|
LL | _n = &2 * _n;
| ^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:189:10
--> $DIR/arithmetic_side_effects.rs:193:10
|
LL | _n = 23 + &85;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:190:10
--> $DIR/arithmetic_side_effects.rs:194:10
|
LL | _n = &23 + 85;
| ^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:191:10
--> $DIR/arithmetic_side_effects.rs:195:10
|
LL | _n = &23 + &85;
| ^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:194:13
--> $DIR/arithmetic_side_effects.rs:198:13
|
LL | let _ = Custom + 0;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:195:13
--> $DIR/arithmetic_side_effects.rs:199:13
|
LL | let _ = Custom + 1;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:196:13
--> $DIR/arithmetic_side_effects.rs:200:13
|
LL | let _ = Custom + 2;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:197:13
--> $DIR/arithmetic_side_effects.rs:201:13
|
LL | let _ = Custom + 0.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:198:13
--> $DIR/arithmetic_side_effects.rs:202:13
|
LL | let _ = Custom + 1.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:199:13
--> $DIR/arithmetic_side_effects.rs:203:13
|
LL | let _ = Custom + 2.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:200:13
--> $DIR/arithmetic_side_effects.rs:204:13
|
LL | let _ = Custom - 0;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:201:13
--> $DIR/arithmetic_side_effects.rs:205:13
|
LL | let _ = Custom - 1;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:202:13
--> $DIR/arithmetic_side_effects.rs:206:13
|
LL | let _ = Custom - 2;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:203:13
--> $DIR/arithmetic_side_effects.rs:207:13
|
LL | let _ = Custom - 0.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:204:13
--> $DIR/arithmetic_side_effects.rs:208:13
|
LL | let _ = Custom - 1.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:205:13
--> $DIR/arithmetic_side_effects.rs:209:13
|
LL | let _ = Custom - 2.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:206:13
--> $DIR/arithmetic_side_effects.rs:210:13
|
LL | let _ = Custom / 0;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:207:13
--> $DIR/arithmetic_side_effects.rs:211:13
|
LL | let _ = Custom / 1;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:208:13
--> $DIR/arithmetic_side_effects.rs:212:13
|
LL | let _ = Custom / 2;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:209:13
--> $DIR/arithmetic_side_effects.rs:213:13
|
LL | let _ = Custom / 0.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:210:13
--> $DIR/arithmetic_side_effects.rs:214:13
|
LL | let _ = Custom / 1.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:211:13
--> $DIR/arithmetic_side_effects.rs:215:13
|
LL | let _ = Custom / 2.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:212:13
--> $DIR/arithmetic_side_effects.rs:216:13
|
LL | let _ = Custom * 0;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:213:13
--> $DIR/arithmetic_side_effects.rs:217:13
|
LL | let _ = Custom * 1;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:214:13
--> $DIR/arithmetic_side_effects.rs:218:13
|
LL | let _ = Custom * 2;
| ^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:215:13
--> $DIR/arithmetic_side_effects.rs:219:13
|
LL | let _ = Custom * 0.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:216:13
--> $DIR/arithmetic_side_effects.rs:220:13
|
LL | let _ = Custom * 1.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:217:13
--> $DIR/arithmetic_side_effects.rs:221:13
|
LL | let _ = Custom * 2.0;
| ^^^^^^^^^^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:220:10
--> $DIR/arithmetic_side_effects.rs:224:10
|
LL | _n = -_n;
| ^^^
error: arithmetic operation that can potentially result in unexpected side-effects
--> $DIR/arithmetic_side_effects.rs:221:10
--> $DIR/arithmetic_side_effects.rs:225:10
|
LL | _n = -&_n;
| ^^^^