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 rustc_lint::{EarlyContext, EarlyLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::source_map::Spanned;
-const ODD_FUNCTIONS_WHITELIST: [&str; 14] = [
+const ALLOWED_ODD_FUNCTIONS: [&str; 14] = [
"asin",
"asinh",
"atan",
}
}
- if let ExprKind::Unary(UnOp::Neg, ref rhs) = expr.kind {
- if let ExprKind::MethodCall(ref path_segment, ref args, _) = rhs.kind {
+ 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();
- if let Some(slf) = args.first() {
- if let ExprKind::Lit(ref lit) = slf.kind {
- match lit.kind {
- LitKind::Int(..) | LitKind::Float(..) => {
- if ODD_FUNCTIONS_WHITELIST
- .iter()
- .any(|odd_function| **odd_function == *path_segment_str)
- {
- return;
- }
- 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,
- );
- },
- _ => (),
- }
- }
+ 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,
+ );
}
}
}
#[must_use]
fn is_bit_op(op: BinOpKind) -> bool {
use rustc_ast::ast::BinOpKind::{BitAnd, BitOr, BitXor, Shl, Shr};
- match op {
- BitXor | BitAnd | BitOr | Shl | Shr => true,
- _ => false,
- }
+ matches!(op, BitXor | BitAnd | BitOr | Shl | Shr)
}
#[must_use]
fn is_arith_op(op: BinOpKind) -> bool {
use rustc_ast::ast::BinOpKind::{Add, Div, Mul, Rem, Sub};
- match op {
- Add | Sub | Mul | Div | Rem => true,
- _ => false,
- }
+ matches!(op, Add | Sub | Mul | Div | Rem)
}