//! lint on manually implemented checked conversions that could be transformed into `try_from`
+use clippy_utils::diagnostics::span_lint_and_sugg;
+use clippy_utils::source::snippet_with_applicability;
+use clippy_utils::{meets_msrv, SpanlessEq};
use if_chain::if_chain;
use rustc_ast::ast::LitKind;
use rustc_errors::Applicability;
use rustc_hir::{BinOp, BinOpKind, Expr, ExprKind, QPath, TyKind};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
-use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
-use crate::utils::{snippet_with_applicability, span_lint_and_sugg, SpanlessEq};
+const CHECKED_CONVERSIONS_MSRV: RustcVersion = RustcVersion::new(1, 34, 0);
declare_clippy_lint! {
/// **What it does:** Checks for explicit bounds checking when casting.
"`try_from` could replace manual bounds checking when casting"
}
-declare_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
+pub struct CheckedConversions {
+ msrv: Option<RustcVersion>,
+}
+
+impl CheckedConversions {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
+
+impl<'tcx> LateLintPass<'tcx> for CheckedConversions {
+ fn check_expr(&mut self, cx: &LateContext<'_>, item: &Expr<'_>) {
+ if !meets_msrv(self.msrv.as_ref(), &CHECKED_CONVERSIONS_MSRV) {
+ return;
+ }
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CheckedConversions {
- 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.kind;
+ if let ExprKind::Binary(op, left, right) = &item.kind;
then {
match op.node {
cx,
CHECKED_CONVERSIONS,
item.span,
- "Checked cast can be simplified.",
+ "checked cast can be simplified",
"try",
format!("{}::try_from({}).is_ok()", to_type, snippet),
applicability,
}
}
}
+
+ extract_msrv_attr!(LateContext);
}
/// Searches for a single check from unsigned to _ is done
}
/// Searches for a combination of upper & lower bound checks
-fn double_check<'a>(cx: &LateContext<'_, '_>, left: &'a Expr<'_>, right: &'a Expr<'_>) -> Option<Conversion<'a>> {
+fn double_check<'a>(cx: &LateContext<'_>, left: &'a Expr<'_>, right: &'a Expr<'_>) -> Option<Conversion<'a>> {
let upper_lower = |l, r| {
let upper = check_upper_bound(l);
let lower = check_lower_bound(r);
impl<'a> Conversion<'a> {
/// Combine multiple conversions if the are compatible
- pub fn combine(self, other: Self, cx: &LateContext<'_, '_>) -> Option<Conversion<'a>> {
+ pub fn combine(self, other: Self, cx: &LateContext<'_>) -> Option<Conversion<'a>> {
if self.is_compatible(&other, cx) {
// Prefer a Conversion that contains a type-constraint
Some(if self.to_type.is_some() { self } else { other })
/// Checks if two conversions are compatible
/// same type of conversion, same 'castee' and same 'to type'
- pub fn is_compatible(&self, other: &Self, cx: &LateContext<'_, '_>) -> bool {
+ pub fn is_compatible(&self, other: &Self, cx: &LateContext<'_>) -> bool {
(self.cvt == other.cvt)
&& (SpanlessEq::new(cx).eq_expr(self.expr_to_cast, other.expr_to_cast))
&& (self.has_compatible_to_type(other))
/// Check for `expr <= (to_type::MAX as from_type)`
fn check_upper_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
if_chain! {
- if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind;
+ if let ExprKind::Binary(ref op, left, right) = &expr.kind;
if let Some((candidate, check)) = normalize_le_ge(op, left, right);
if let Some((from, to)) = get_types_from_cast(check, INTS, "max_value", "MAX");
}
// First of we need a binary containing the expression & the cast
- if let ExprKind::Binary(ref op, ref left, ref right) = &expr.kind {
+ if let ExprKind::Binary(ref op, left, right) = &expr.kind {
normalize_le_ge(op, right, left).and_then(|(l, r)| check_function(l, r))
} else {
None
// or `to_type::MAX as from_type`
let call_from_cast: Option<(&Expr<'_>, &str)> = if_chain! {
// to_type::max_value(), from_type
- if let ExprKind::Cast(ref limit, ref from_type) = &expr.kind;
+ if let ExprKind::Cast(limit, 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);
let limit_from: Option<(&Expr<'_>, &str)> = call_from_cast.or_else(|| {
if_chain! {
// `from_type::from, to_type::max_value()`
- if let ExprKind::Call(ref from_func, ref args) = &expr.kind;
+ if let ExprKind::Call(from_func, args) = &expr.kind;
// `to_type::max_value()`
if args.len() == 1;
if let limit = &args[0];
/// Gets the type which implements the called function
fn get_implementing_type<'a>(path: &QPath<'_>, candidates: &'a [&str], function: &str) -> Option<&'a str> {
if_chain! {
- if let QPath::TypeRelative(ref ty, ref path) = &path;
+ if let QPath::TypeRelative(ty, path) = &path;
if path.ident.name.as_str() == function;
- if let TyKind::Path(QPath::Resolved(None, ref tp)) = &ty.kind;
+ if let TyKind::Path(QPath::Resolved(None, tp)) = &ty.kind;
if let [int] = &*tp.segments;
- let name = &int.ident.name.as_str();
-
then {
- candidates.iter().find(|c| name == *c).cloned()
+ let name = &int.ident.name.as_str();
+ candidates.iter().find(|c| name == *c).copied()
} else {
None
}
/// Gets the type as a string, if it is a supported integer
fn int_ty_to_sym<'tcx>(path: &QPath<'_>) -> Option<&'tcx str> {
if_chain! {
- if let QPath::Resolved(_, ref path) = *path;
+ if let QPath::Resolved(_, path) = *path;
if let [ty] = &*path.segments;
- let name = &ty.ident.name.as_str();
-
then {
- INTS.iter().find(|c| name == *c).cloned()
+ let name = &ty.ident.name.as_str();
+ INTS.iter().find(|c| name == *c).copied()
} else {
None
}
projects / rust.git / blobdiff