//! lint on manually implemented checked conversions that could be transformed into `try_from`
use if_chain::if_chain;
+use rustc::declare_lint_pass;
use rustc::hir::*;
use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
use rustc_errors::Applicability;
+use rustc_session::declare_tool_lint;
use syntax::ast::LitKind;
use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
/// Could be written:
///
/// ```rust
+ /// # use std::convert::TryFrom;
+ /// # let foo = 1;
/// # let _ =
/// i32::try_from(foo).is_ok()
/// # ;
fn check_expr(&mut self, cx: &LateContext<'_, '_>, item: &Expr) {
let result = if_chain! {
if !in_external_macro(cx.sess(), item.span);
- if let ExprKind::Binary(op, ref left, ref right) = &item.node;
+ if let ExprKind::Binary(op, ref left, ref right) = &item.kind;
then {
match op.node {
impl ConversionType {
/// Creates a conversion type if the type is allowed & conversion is valid
+ #[must_use]
fn try_new(from: &str, to: &str) -> Option<Self> {
if UINTS.contains(&from) {
Some(Self::FromUnsigned)
/// Check for `expr <= (to_type::max_value() as from_type)`
fn check_upper_bound(expr: &Expr) -> Option<Conversion<'_>> {
if_chain! {
- if let ExprKind::Binary(ref op, ref left, ref right) = &expr.node;
+ if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind;
if let Some((candidate, check)) = normalize_le_ge(op, left, right);
if let Some((from, to)) = get_types_from_cast(check, MAX_VALUE, INTS);
}
// First of we need a binary containing the expression & the cast
- if let ExprKind::Binary(ref op, ref left, ref right) = &expr.node {
+ if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind {
normalize_le_ge(op, right, left).and_then(|(l, r)| check_function(l, r))
} else {
None
/// Check for `expr >= 0`
fn check_lower_bound_zero<'a>(candidate: &'a Expr, check: &'a Expr) -> Option<Conversion<'a>> {
if_chain! {
- if let ExprKind::Lit(ref lit) = &check.node;
+ if let ExprKind::Lit(ref lit) = &check.kind;
if let LitKind::Int(0, _) = &lit.node;
then {
// `to_type::maxmin_value() as from_type`
let call_from_cast: Option<(&Expr, &str)> = if_chain! {
// to_type::maxmin_value(), from_type
- if let ExprKind::Cast(ref limit, ref from_type) = &expr.node;
- if let TyKind::Path(ref from_type_path) = &from_type.node;
+ if let ExprKind::Cast(ref limit, ref from_type) = &expr.kind;
+ if let TyKind::Path(ref from_type_path) = &from_type.kind;
if let Some(from_sym) = int_ty_to_sym(from_type_path);
then {
let limit_from: Option<(&Expr, &str)> = call_from_cast.or_else(|| {
if_chain! {
// `from_type::from, to_type::maxmin_value()`
- if let ExprKind::Call(ref from_func, ref args) = &expr.node;
+ if let ExprKind::Call(ref from_func, ref args) = &expr.kind;
// `to_type::maxmin_value()`
if args.len() == 1;
if let limit = &args[0];
// `from_type::from`
- if let ExprKind::Path(ref path) = &from_func.node;
+ if let ExprKind::Path(ref path) = &from_func.kind;
if let Some(from_sym) = get_implementing_type(path, INTS, FROM);
then {
if let Some((limit, from_type)) = limit_from {
if_chain! {
- if let ExprKind::Call(ref fun_name, _) = &limit.node;
+ if let ExprKind::Call(ref fun_name, _) = &limit.kind;
// `to_type, maxmin_value`
- if let ExprKind::Path(ref path) = &fun_name.node;
+ if let ExprKind::Path(ref path) = &fun_name.kind;
// `to_type`
if let Some(to_type) = get_implementing_type(path, types, func);
if_chain! {
if let QPath::TypeRelative(ref ty, ref path) = &path;
if path.ident.name.as_str() == function;
- if let TyKind::Path(QPath::Resolved(None, ref tp)) = &ty.node;
+ if let TyKind::Path(QPath::Resolved(None, ref tp)) = &ty.kind;
if let [int] = &*tp.segments;
let name = &int.ident.name.as_str();