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use syntax::ast::{Expr, ExprKind, UnOp};
use rustc::lint::*;
use utils::{span_lint_and_then, snippet};
declare_lint! {
pub DEREF_ADDROF,
Warn,
"use of `*&` or `*&mut` in an expression"
}
pub struct Pass;
impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
lint_array!(DEREF_ADDROF)
}
}
fn without_parens(mut e: &Expr) -> &Expr {
while let ExprKind::Paren(ref child_e) = e.node {
e = child_e;
}
e
}
impl EarlyLintPass for Pass {
fn check_expr(&mut self, cx: &EarlyContext, e: &Expr) {
if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.node {
if let ExprKind::AddrOf(_, ref addrof_target) = without_parens(deref_target).node {
span_lint_and_then(cx, DEREF_ADDROF, e.span, "immediately dereferencing a reference", |db| {
db.span_suggestion(e.span, "try this", format!("{}", snippet(cx, addrof_target.span, "_")));
});
}
}
}
}