-use crate::utils::{in_macro, snippet_with_applicability, span_lint_and_sugg};
-use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::utils::{snippet_with_applicability, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc_ast::ast::{BinOpKind, Expr, ExprKind, LitKind, UnOp};
use rustc_errors::Applicability;
-use syntax::ast::*;
-use syntax::source_map::Spanned;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::source_map::Spanned;
+
+const ALLOWED_ODD_FUNCTIONS: [&str; 14] = [
+ "asin",
+ "asinh",
+ "atan",
+ "atanh",
+ "cbrt",
+ "fract",
+ "round",
+ "signum",
+ "sin",
+ "sinh",
+ "tan",
+ "tanh",
+ "to_degrees",
+ "to_radians",
+];
-/// **What it does:** Checks for operations where precedence may be unclear
-/// and suggests to add parentheses. Currently it catches the following:
-/// * mixed usage of arithmetic and bit shifting/combining operators without
-/// parentheses
-/// * a "negative" numeric literal (which is really a unary `-` followed by a
-/// numeric literal)
-/// followed by a method call
-///
-/// **Why is this bad?** Not everyone knows the precedence of those operators by
-/// heart, so expressions like these may trip others trying to reason about the
-/// code.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// * `1 << 2 + 3` equals 32, while `(1 << 2) + 3` equals 7
-/// * `-1i32.abs()` equals -1, while `(-1i32).abs()` equals 1
declare_clippy_lint! {
+ /// **What it does:** Checks for operations where precedence may be unclear
+ /// and suggests to add parentheses. Currently it catches the following:
+ /// * mixed usage of arithmetic and bit shifting/combining operators without
+ /// parentheses
+ /// * a "negative" numeric literal (which is really a unary `-` followed by a
+ /// numeric literal)
+ /// followed by a method call
+ ///
+ /// **Why is this bad?** Not everyone knows the precedence of those operators by
+ /// heart, so expressions like these may trip others trying to reason about the
+ /// code.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// * `1 << 2 + 3` equals 32, while `(1 << 2) + 3` equals 7
+ /// * `-1i32.abs()` equals -1, while `(-1i32).abs()` equals 1
pub PRECEDENCE,
complexity,
"operations where precedence may be unclear"
}
-#[derive(Copy, Clone)]
-pub struct Precedence;
-
-impl LintPass for Precedence {
- fn get_lints(&self) -> LintArray {
- lint_array!(PRECEDENCE)
- }
-
- fn name(&self) -> &'static str {
- "Precedence"
- }
-}
+declare_lint_pass!(Precedence => [PRECEDENCE]);
impl EarlyLintPass for Precedence {
fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
- if in_macro(expr.span) {
+ if expr.span.from_expansion() {
return;
}
- if let ExprKind::Binary(Spanned { node: op, .. }, ref left, ref right) = expr.node {
+ if let ExprKind::Binary(Spanned { node: op, .. }, ref left, ref right) = expr.kind {
let span_sugg = |expr: &Expr, sugg, appl| {
span_lint_and_sugg(
cx,
}
}
- if let ExprKind::Unary(UnOp::Neg, ref rhs) = expr.node {
- if let ExprKind::MethodCall(_, ref args) = rhs.node {
- if let Some(slf) = args.first() {
- if let ExprKind::Lit(ref lit) = slf.node {
- match lit.node {
- LitKind::Int(..) | LitKind::Float(..) | LitKind::FloatUnsuffixed(..) => {
- let mut applicability = Applicability::MachineApplicable;
- span_lint_and_sugg(
- cx,
- PRECEDENCE,
- expr.span,
- "unary minus has lower precedence than method call",
- "consider adding parentheses to clarify your intent",
- format!(
- "-({})",
- snippet_with_applicability(cx, rhs.span, "..", &mut applicability)
- ),
- applicability,
- );
- },
- _ => (),
- }
- }
+ if let ExprKind::Unary(UnOp::Neg, operand) = &expr.kind {
+ let mut arg = operand;
+
+ let mut all_odd = true;
+ while let ExprKind::MethodCall(path_segment, args, _) = &arg.kind {
+ let path_segment_str = path_segment.ident.name.as_str();
+ all_odd &= ALLOWED_ODD_FUNCTIONS
+ .iter()
+ .any(|odd_function| **odd_function == *path_segment_str);
+ arg = args.first().expect("A method always has a receiver.");
+ }
+
+ if_chain! {
+ if !all_odd;
+ if let ExprKind::Lit(lit) = &arg.kind;
+ if let LitKind::Int(..) | LitKind::Float(..) = &lit.kind;
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
+ cx,
+ PRECEDENCE,
+ expr.span,
+ "unary minus has lower precedence than method call",
+ "consider adding parentheses to clarify your intent",
+ format!(
+ "-({})",
+ snippet_with_applicability(cx, operand.span, "..", &mut applicability)
+ ),
+ applicability,
+ );
}
}
}
}
fn is_arith_expr(expr: &Expr) -> bool {
- match expr.node {
+ match expr.kind {
ExprKind::Binary(Spanned { node: op, .. }, _, _) => is_arith_op(op),
_ => false,
}
}
+#[must_use]
fn is_bit_op(op: BinOpKind) -> bool {
- use syntax::ast::BinOpKind::*;
- match op {
- BitXor | BitAnd | BitOr | Shl | Shr => true,
- _ => false,
- }
+ use rustc_ast::ast::BinOpKind::{BitAnd, BitOr, BitXor, Shl, Shr};
+ matches!(op, BitXor | BitAnd | BitOr | Shl | Shr)
}
+#[must_use]
fn is_arith_op(op: BinOpKind) -> bool {
- use syntax::ast::BinOpKind::*;
- match op {
- Add | Sub | Mul | Div | Rem => true,
- _ => false,
- }
+ use rustc_ast::ast::BinOpKind::{Add, Div, Mul, Rem, Sub};
+ matches!(op, Add | Sub | Mul | Div | Rem)
}