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samueltardieusamueltardieu
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unnecessary_ip_addr_parse: new lint
This lint detects parsing of string literals into IP addresses when they are known correct.
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‎CHANGELOG.md

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@@ -6155,6 +6155,7 @@ Released 2018-09-13
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[`panic_params`]: https://rust-lang.github.io/rust-clippy/master/index.html#panic_params
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[`panicking_overflow_checks`]: https://rust-lang.github.io/rust-clippy/master/index.html#panicking_overflow_checks
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[`panicking_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#panicking_unwrap
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[`parsed_string_literals`]: https://rust-lang.github.io/rust-clippy/master/index.html#parsed_string_literals
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[`partial_pub_fields`]: https://rust-lang.github.io/rust-clippy/master/index.html#partial_pub_fields
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[`partialeq_ne_impl`]: https://rust-lang.github.io/rust-clippy/master/index.html#partialeq_ne_impl
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[`partialeq_to_none`]: https://rust-lang.github.io/rust-clippy/master/index.html#partialeq_to_none

‎clippy_lints/src/declared_lints.rs

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@@ -437,6 +437,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
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crate::methods::OPTION_MAP_OR_NONE_INFO,
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crate::methods::OR_FUN_CALL_INFO,
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crate::methods::OR_THEN_UNWRAP_INFO,
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crate::methods::PARSED_STRING_LITERALS_INFO,
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crate::methods::PATH_BUF_PUSH_OVERWRITE_INFO,
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crate::methods::PATH_ENDS_WITH_EXT_INFO,
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crate::methods::RANGE_ZIP_WITH_LEN_INFO,

‎clippy_lints/src/lib.rs

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@@ -1,9 +1,11 @@
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#![feature(array_windows)]
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#![feature(box_patterns)]
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#![feature(cow_is_borrowed)]
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#![feature(macro_metavar_expr_concat)]
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#![feature(f128)]
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#![feature(f16)]
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#![feature(if_let_guard)]
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#![feature(ip_as_octets)]
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#![feature(iter_intersperse)]
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#![feature(iter_partition_in_place)]
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#![feature(never_type)]

‎clippy_lints/src/methods/mod.rs

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@@ -88,6 +88,7 @@ mod option_map_or_none;
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mod option_map_unwrap_or;
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mod or_fun_call;
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mod or_then_unwrap;
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mod parsed_string_literals;
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mod path_buf_push_overwrite;
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mod path_ends_with_ext;
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mod range_zip_with_len;
@@ -4528,6 +4529,34 @@ declare_clippy_lint! {
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"detect swap with a temporary value"
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}
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declare_clippy_lint! {
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/// ### What it does
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/// Checks for parsing IPv4/IPv6 string literals
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///
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/// ### Why is this bad?
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/// Parsing known-correct IP address at runtime consumes resources and forces to
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/// handle the (non-existing) errors.
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///
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/// ### Example
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/// ```no_run
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/// use std::net::Ipv4Addr;
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///
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/// let addr1: Ipv4Addr = "10.2.3.4".parse().unwrap();
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/// let addr2: Ipv4Addr = "127.0.0.1".parse().unwrap();
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/// ```
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/// Use instead:
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/// ```no_run
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/// use std::net::Ipv4Addr;
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///
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/// let addr1: Ipv4Addr = Ipv4Addr::new(10, 2, 3, 4);
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/// let addr2: Ipv4Addr = Ipv4Addr::LOCALHOST;
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/// ```
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#[clippy::version = "1.89.0"]
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pub PARSED_STRING_LITERALS,
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complexity,
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"known-correct literal IP address parsing"
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}
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#[expect(clippy::struct_excessive_bools)]
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pub struct Methods {
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avoid_breaking_exported_api: bool,
@@ -4706,6 +4735,7 @@ impl_lint_pass!(Methods => [
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MANUAL_CONTAINS,
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IO_OTHER_ERROR,
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SWAP_WITH_TEMPORARY,
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PARSED_STRING_LITERALS,
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]);
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/// Extracts a method call name, args, and `Span` of the method name.
@@ -5420,6 +5450,9 @@ impl Methods {
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Some((sym::or, recv, [or_arg], or_span, _)) => {
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or_then_unwrap::check(cx, expr, recv, or_arg, or_span);
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},
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Some((sym::parse, recv, [], _, _)) => {
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parsed_string_literals::check(cx, expr, recv, self.msrv);
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},
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_ => {},
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}
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unnecessary_literal_unwrap::check(cx, expr, recv, name, args);

‎clippy_lints/src/methods/parsed_string_literals.rs

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@@ -0,0 +1,91 @@
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use std::borrow::Cow;
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use std::net::{Ipv4Addr, Ipv6Addr};
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use clippy_utils::diagnostics::span_lint_and_sugg;
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use clippy_utils::msrvs::{self, Msrv};
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use clippy_utils::source::SpanRangeExt;
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use clippy_utils::sym;
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use clippy_utils::ty::is_type_diagnostic_item;
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use rustc_ast::LitKind;
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use rustc_errors::Applicability;
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use rustc_hir::{Expr, ExprKind};
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use rustc_lint::LateContext;
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use rustc_span::Symbol;
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use super::PARSED_STRING_LITERALS;
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pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, msrv: Msrv) {
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if let ExprKind::Lit(lit) = recv.kind
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&& let LitKind::Str(str, _) = lit.node
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{
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let consts_available = || msrv.meets(cx, msrvs::IPADDR_CONSTANTS);
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let ty = cx.typeck_results().expr_ty(expr);
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if is_type_diagnostic_item(cx, ty, sym::Ipv4Addr)
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&& let Some(sugg) = ipv4_subst(str, consts_available())
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{
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maybe_emit_lint(cx, expr, sugg.is_borrowed(), sugg);
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} else if is_type_diagnostic_item(cx, ty, sym::Ipv6Addr)
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&& let Some(sugg) = ipv6_subst(str, consts_available())
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{
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maybe_emit_lint(cx, expr, sugg.is_borrowed(), sugg);
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} else if is_type_diagnostic_item(cx, ty, sym::IpAddr) {
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let with_consts = consts_available();
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if let Some(sugg) = ipv4_subst(str, with_consts) {
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maybe_emit_lint(cx, expr, sugg.is_borrowed(), format!("IpAddr::V4({sugg})").into());
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} else if let Some(sugg) = ipv6_subst(str, with_consts) {
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maybe_emit_lint(cx, expr, sugg.is_borrowed(), format!("IpAddr::V6({sugg})").into());
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}
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}
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}
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}
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/// Suggests a replacement if `addr` is a correct IPv4 address
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fn ipv4_subst(addr: Symbol, with_consts: bool) -> Option<Cow<'static, str>> {
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addr.as_str().parse().ok().map(|ipv4: Ipv4Addr| {
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if with_consts && ipv4.as_octets() == &[127, 0, 0, 1] {
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"Ipv4Addr::LOCALHOST".into()
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} else if with_consts && ipv4.is_broadcast() {
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"Ipv4Addr::BROADCAST".into()
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} else if with_consts && ipv4.is_unspecified() {
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"Ipv4Addr::UNSPECIFIED".into()
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} else {
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let ipv4 = ipv4.as_octets();
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format!("Ipv4Addr::new({}, {}, {}, {})", ipv4[0], ipv4[1], ipv4[2], ipv4[3]).into()
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}
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})
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}
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/// Suggests a replacement if `addr` is a correct IPv6 address
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fn ipv6_subst(addr: Symbol, with_consts: bool) -> Option<Cow<'static, str>> {
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addr.as_str().parse().ok().map(|ipv6: Ipv6Addr| {
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if with_consts && ipv6.is_loopback() {
62+
"Ipv6Addr::LOCALHOST".into()
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} else if with_consts && ipv6.is_unspecified() {
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"Ipv6Addr::UNSPECIFIED".into()
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} else {
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format!(
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"Ipv6Addr::new([{}])",
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ipv6.segments()
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.map(|n| if n < 2 { n.to_string() } else { format!("{n:#x}") })
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.join(", ")
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)
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.into()
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}
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})
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}
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/// Emit the lint if the length of `sugg` is no longer than the original `expr` span, or if `force`
78+
/// is set.
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fn maybe_emit_lint(cx: &LateContext<'_>, expr: &Expr<'_>, force: bool, sugg: Cow<'_, str>) {
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if force || expr.span.check_source_text(cx, |snip| snip.len() >= sugg.len()) {
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span_lint_and_sugg(
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cx,
83+
PARSED_STRING_LITERALS,
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expr.span,
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"unnecessary runtime parsing of IP address",
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"use",
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sugg.into(),
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Applicability::MaybeIncorrect,
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);
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}
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}

‎clippy_utils/src/msrvs.rs

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@@ -68,7 +68,7 @@ msrv_aliases! {
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1,33,0 { UNDERSCORE_IMPORTS }
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1,32,0 { CONST_IS_POWER_OF_TWO }
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1,31,0 { OPTION_REPLACE }
71-
1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES }
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1,30,0 { ITERATOR_FIND_MAP, TOOL_ATTRIBUTES, IPADDR_CONSTANTS }
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1,29,0 { ITER_FLATTEN }
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1,28,0 { FROM_BOOL, REPEAT_WITH, SLICE_FROM_REF }
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1,27,0 { ITERATOR_TRY_FOLD }

‎tests/ui/parsed_string_literals.fixed

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#![warn(clippy::parsed_string_literals)]
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use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
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5+
fn main() {
6+
_ = Ipv4Addr::new(137, 194, 161, 2);
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//~^ parsed_string_literals
8+
9+
_ = Ipv4Addr::LOCALHOST;
10+
//~^ parsed_string_literals
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12+
_ = Ipv4Addr::BROADCAST;
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//~^ parsed_string_literals
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15+
_ = Ipv4Addr::UNSPECIFIED;
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//~^ parsed_string_literals
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18+
// Wrong address family
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_ = "::1".parse::<Ipv4Addr>().unwrap();
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_ = "127.0.0.1".parse::<Ipv6Addr>().unwrap();
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_ = Ipv6Addr::LOCALHOST;
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//~^ parsed_string_literals
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25+
_ = Ipv6Addr::UNSPECIFIED;
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//~^ parsed_string_literals
27+
28+
_ = IpAddr::V6(Ipv6Addr::LOCALHOST);
29+
//~^ parsed_string_literals
30+
31+
_ = IpAddr::V6(Ipv6Addr::UNSPECIFIED);
32+
//~^ parsed_string_literals
33+
34+
// The substition text would be larger than the original and wouldn't use constants
35+
_ = "2a04:8ec0:0:47::131".parse::<Ipv6Addr>().unwrap();
36+
_ = "2a04:8ec0:0:47::131".parse::<IpAddr>().unwrap();
37+
}
38+
39+
#[clippy::msrv = "1.29"]
40+
fn msrv_under() {
41+
_ = "::".parse::<IpAddr>().unwrap();
42+
}

‎tests/ui/parsed_string_literals.rs

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1+
#![warn(clippy::parsed_string_literals)]
2+
3+
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
4+
5+
fn main() {
6+
_ = "137.194.161.2".parse::<Ipv4Addr>().unwrap();
7+
//~^ parsed_string_literals
8+
9+
_ = "127.0.0.1".parse::<Ipv4Addr>().unwrap();
10+
//~^ parsed_string_literals
11+
12+
_ = "255.255.255.255".parse::<Ipv4Addr>().unwrap();
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//~^ parsed_string_literals
14+
15+
_ = "0.0.0.0".parse::<Ipv4Addr>().unwrap();
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//~^ parsed_string_literals
17+
18+
// Wrong address family
19+
_ = "::1".parse::<Ipv4Addr>().unwrap();
20+
_ = "127.0.0.1".parse::<Ipv6Addr>().unwrap();
21+
22+
_ = "::1".parse::<Ipv6Addr>().unwrap();
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//~^ parsed_string_literals
24+
25+
_ = "::".parse::<Ipv6Addr>().unwrap();
26+
//~^ parsed_string_literals
27+
28+
_ = "::1".parse::<IpAddr>().unwrap();
29+
//~^ parsed_string_literals
30+
31+
_ = "::".parse::<IpAddr>().unwrap();
32+
//~^ parsed_string_literals
33+
34+
// The substition text would be larger than the original and wouldn't use constants
35+
_ = "2a04:8ec0:0:47::131".parse::<Ipv6Addr>().unwrap();
36+
_ = "2a04:8ec0:0:47::131".parse::<IpAddr>().unwrap();
37+
}
38+
39+
#[clippy::msrv = "1.29"]
40+
fn msrv_under() {
41+
_ = "::".parse::<IpAddr>().unwrap();
42+
}

‎tests/ui/parsed_string_literals.stderr

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error: unnecessary runtime parsing of IP address
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--> tests/ui/parsed_string_literals.rs:6:9
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|
4+
LL | _ = "137.194.161.2".parse::<Ipv4Addr>().unwrap();
5+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv4Addr::new(137, 194, 161, 2)`
6+
|
7+
= note: `-D clippy::parsed-string-literals` implied by `-D warnings`
8+
= help: to override `-D warnings` add `#[allow(clippy::parsed_string_literals)]`
9+
10+
error: unnecessary runtime parsing of IP address
11+
--> tests/ui/parsed_string_literals.rs:9:9
12+
|
13+
LL | _ = "127.0.0.1".parse::<Ipv4Addr>().unwrap();
14+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv4Addr::LOCALHOST`
15+
16+
error: unnecessary runtime parsing of IP address
17+
--> tests/ui/parsed_string_literals.rs:12:9
18+
|
19+
LL | _ = "255.255.255.255".parse::<Ipv4Addr>().unwrap();
20+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv4Addr::BROADCAST`
21+
22+
error: unnecessary runtime parsing of IP address
23+
--> tests/ui/parsed_string_literals.rs:15:9
24+
|
25+
LL | _ = "0.0.0.0".parse::<Ipv4Addr>().unwrap();
26+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv4Addr::UNSPECIFIED`
27+
28+
error: unnecessary runtime parsing of IP address
29+
--> tests/ui/parsed_string_literals.rs:22:9
30+
|
31+
LL | _ = "::1".parse::<Ipv6Addr>().unwrap();
32+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv6Addr::LOCALHOST`
33+
34+
error: unnecessary runtime parsing of IP address
35+
--> tests/ui/parsed_string_literals.rs:25:9
36+
|
37+
LL | _ = "::".parse::<Ipv6Addr>().unwrap();
38+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `Ipv6Addr::UNSPECIFIED`
39+
40+
error: unnecessary runtime parsing of IP address
41+
--> tests/ui/parsed_string_literals.rs:28:9
42+
|
43+
LL | _ = "::1".parse::<IpAddr>().unwrap();
44+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `IpAddr::V6(Ipv6Addr::LOCALHOST)`
45+
46+
error: unnecessary runtime parsing of IP address
47+
--> tests/ui/parsed_string_literals.rs:31:9
48+
|
49+
LL | _ = "::".parse::<IpAddr>().unwrap();
50+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use: `IpAddr::V6(Ipv6Addr::UNSPECIFIED)`
51+
52+
error: aborting due to 8 previous errors
53+

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