-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_lint, lint_array};
-use if_chain::if_chain;
-use rustc::hir::*;
use crate::utils::{span_lint, SpanlessEq};
+use if_chain::if_chain;
+use rustc_hir::{BinOpKind, Expr, ExprKind, QPath};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
-/// **What it does:** Detects classic underflow/overflow checks.
-///
-/// **Why is this bad?** Most classic C underflow/overflow checks will fail in
-/// Rust. Users can use functions like `overflowing_*` and `wrapping_*` instead.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// a + b < a
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Detects classic underflow/overflow checks.
+ ///
+ /// **Why is this bad?** Most classic C underflow/overflow checks will fail in
+ /// Rust. Users can use functions like `overflowing_*` and `wrapping_*` instead.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// # let a = 1;
+ /// # let b = 2;
+ /// a + b < a;
+ /// ```
pub OVERFLOW_CHECK_CONDITIONAL,
complexity,
"overflow checks inspired by C which are likely to panic"
}
-#[derive(Copy, Clone)]
-pub struct OverflowCheckConditional;
-
-impl LintPass for OverflowCheckConditional {
- fn get_lints(&self) -> LintArray {
- lint_array!(OVERFLOW_CHECK_CONDITIONAL)
- }
-}
+declare_lint_pass!(OverflowCheckConditional => [OVERFLOW_CHECK_CONDITIONAL]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for OverflowCheckConditional {
+impl<'tcx> LateLintPass<'tcx> for OverflowCheckConditional {
// a + b < a, a > a + b, a < a - b, a - b > a
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
let eq = |l, r| SpanlessEq::new(cx).eq_path_segment(l, r);
if_chain! {
- if let ExprKind::Binary(ref op, ref first, ref second) = expr.node;
- if let ExprKind::Binary(ref op2, ref ident1, ref ident2) = first.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path1)) = ident1.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path2)) = ident2.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path3)) = second.node;
+ if let ExprKind::Binary(ref op, ref first, ref second) = expr.kind;
+ if let ExprKind::Binary(ref op2, ref ident1, ref ident2) = first.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path1)) = ident1.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path2)) = ident2.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path3)) = second.kind;
if eq(&path1.segments[0], &path3.segments[0]) || eq(&path2.segments[0], &path3.segments[0]);
- if cx.tables.expr_ty(ident1).is_integral();
- if cx.tables.expr_ty(ident2).is_integral();
+ if cx.typeck_results().expr_ty(ident1).is_integral();
+ if cx.typeck_results().expr_ty(ident2).is_integral();
then {
if let BinOpKind::Lt = op.node {
if let BinOpKind::Add = op2.node {
span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
- "You are trying to use classic C overflow conditions that will fail in Rust.");
+ "you are trying to use classic C overflow conditions that will fail in Rust");
}
}
if let BinOpKind::Gt = op.node {
if let BinOpKind::Sub = op2.node {
span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
- "You are trying to use classic C underflow conditions that will fail in Rust.");
+ "you are trying to use classic C underflow conditions that will fail in Rust");
}
}
}
}
if_chain! {
- if let ExprKind::Binary(ref op, ref first, ref second) = expr.node;
- if let ExprKind::Binary(ref op2, ref ident1, ref ident2) = second.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path1)) = ident1.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path2)) = ident2.node;
- if let ExprKind::Path(QPath::Resolved(_, ref path3)) = first.node;
+ if let ExprKind::Binary(ref op, ref first, ref second) = expr.kind;
+ if let ExprKind::Binary(ref op2, ref ident1, ref ident2) = second.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path1)) = ident1.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path2)) = ident2.kind;
+ if let ExprKind::Path(QPath::Resolved(_, ref path3)) = first.kind;
if eq(&path1.segments[0], &path3.segments[0]) || eq(&path2.segments[0], &path3.segments[0]);
- if cx.tables.expr_ty(ident1).is_integral();
- if cx.tables.expr_ty(ident2).is_integral();
+ if cx.typeck_results().expr_ty(ident1).is_integral();
+ if cx.typeck_results().expr_ty(ident2).is_integral();
then {
if let BinOpKind::Gt = op.node {
if let BinOpKind::Add = op2.node {
span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
- "You are trying to use classic C overflow conditions that will fail in Rust.");
+ "you are trying to use classic C overflow conditions that will fail in Rust");
}
}
if let BinOpKind::Lt = op.node {
if let BinOpKind::Sub = op2.node {
span_lint(cx, OVERFLOW_CHECK_CONDITIONAL, expr.span,
- "You are trying to use classic C underflow conditions that will fail in Rust.");
+ "you are trying to use classic C underflow conditions that will fail in Rust");
}
}
}