//! lint on manually implemented checked conversions that could be transformed into `try_from`
use if_chain::if_chain;
-use rustc::hir::*;
-use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc::lint::in_external_macro;
use rustc_errors::Applicability;
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_lint_pass, 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()
/// # ;
declare_lint_pass!(CheckedConversions => [CHECKED_CONVERSIONS]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CheckedConversions {
- fn check_expr(&mut self, cx: &LateContext<'_, '_>, item: &Expr) {
+ 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 {
/// Searches for a single check from unsigned to _ is done
/// todo: check for case signed -> larger unsigned == only x >= 0
-fn single_check(expr: &Expr) -> Option<Conversion<'_>> {
+fn single_check<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
check_upper_bound(expr).filter(|cv| cv.cvt == ConversionType::FromUnsigned)
}
/// 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);
#[derive(Clone, Debug)]
struct Conversion<'a> {
cvt: ConversionType,
- expr_to_cast: &'a Expr,
+ expr_to_cast: &'a Expr<'a>,
to_type: Option<&'a str>,
}
}
/// Try to construct a new conversion if the conversion type is valid
- fn try_new(expr_to_cast: &'a Expr, from_type: &str, to_type: &'a str) -> Option<Conversion<'a>> {
+ fn try_new(expr_to_cast: &'a Expr<'_>, from_type: &str, to_type: &'a str) -> Option<Conversion<'a>> {
ConversionType::try_new(from_type, to_type).map(|cvt| Conversion {
cvt,
expr_to_cast,
}
/// Construct a new conversion without type constraint
- fn new_any(expr_to_cast: &'a Expr) -> Conversion<'a> {
+ fn new_any(expr_to_cast: &'a Expr<'_>) -> Conversion<'a> {
Conversion {
cvt: ConversionType::SignedToUnsigned,
expr_to_cast,
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(ConversionType::FromUnsigned)
+ Some(Self::FromUnsigned)
} else if SINTS.contains(&from) {
if UINTS.contains(&to) {
- Some(ConversionType::SignedToUnsigned)
+ Some(Self::SignedToUnsigned)
} else if SINTS.contains(&to) {
- Some(ConversionType::SignedToSigned)
+ Some(Self::SignedToSigned)
} else {
None
}
}
/// Check for `expr <= (to_type::max_value() as from_type)`
-fn check_upper_bound(expr: &Expr) -> Option<Conversion<'_>> {
+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.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);
}
/// Check for `expr >= 0|(to_type::min_value() as from_type)`
-fn check_lower_bound(expr: &Expr) -> Option<Conversion<'_>> {
- fn check_function<'a>(candidate: &'a Expr, check: &'a Expr) -> Option<Conversion<'a>> {
+fn check_lower_bound<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<Conversion<'tcx>> {
+ fn check_function<'a>(candidate: &'a Expr<'a>, check: &'a Expr<'a>) -> Option<Conversion<'a>> {
(check_lower_bound_zero(candidate, check)).or_else(|| (check_lower_bound_min(candidate, check)))
}
// 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>> {
+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 {
}
/// Check for `expr >= (to_type::min_value() as from_type)`
-fn check_lower_bound_min<'a>(candidate: &'a Expr, check: &'a Expr) -> Option<Conversion<'a>> {
+fn check_lower_bound_min<'a>(candidate: &'a Expr<'_>, check: &'a Expr<'_>) -> Option<Conversion<'a>> {
if let Some((from, to)) = get_types_from_cast(check, MIN_VALUE, SINTS) {
Conversion::try_new(candidate, from, to)
} else {
}
/// Tries to extract the from- and to-type from a cast expression
-fn get_types_from_cast<'a>(expr: &'a Expr, func: &'a str, types: &'a [&str]) -> Option<(&'a str, &'a str)> {
+fn get_types_from_cast<'a>(expr: &'a Expr<'_>, func: &'a str, types: &'a [&str]) -> Option<(&'a str, &'a str)> {
// `to_type::maxmin_value() as from_type`
- let call_from_cast: Option<(&Expr, &str)> = if_chain! {
+ 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 {
};
// `from_type::from(to_type::maxmin_value())`
- let limit_from: Option<(&Expr, &str)> = call_from_cast.or_else(|| {
+ 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);
}
/// Gets the type which implements the called function
-fn get_implementing_type<'a>(path: &QPath, candidates: &'a [&str], function: &str) -> Option<&'a str> {
+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 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();
}
/// Gets the type as a string, if it is a supported integer
-fn int_ty_to_sym(path: &QPath) -> Option<&str> {
+fn int_ty_to_sym<'tcx>(path: &QPath<'_>) -> Option<&'tcx str> {
if_chain! {
if let QPath::Resolved(_, ref path) = *path;
if let [ty] = &*path.segments;
}
/// Will return the expressions as if they were expr1 <= expr2
-fn normalize_le_ge<'a>(op: &BinOp, left: &'a Expr, right: &'a Expr) -> Option<(&'a Expr, &'a Expr)> {
+fn normalize_le_ge<'a>(op: &BinOp, left: &'a Expr<'a>, right: &'a Expr<'a>) -> Option<(&'a Expr<'a>, &'a Expr<'a>)> {
match op.node {
BinOpKind::Le => Some((left, right)),
BinOpKind::Ge => Some((right, left)),
projects / rust.git / blobdiff