add io_other_error lint (rust-lang#14022)

fixes rust-lang#12717.

r? @xFrednet

----

changelog: add [`io_other_error`] lint

Author: xFrednet

CHANGELOG.md

@@ -5726,6 +5726,7 @@ Released 2018-09-13
 [`invalid_utf8_in_unchecked`]: https://rust-lang.github.io/rust-clippy/master/index.html#invalid_utf8_in_unchecked
 [`inverted_saturating_sub`]: https://rust-lang.github.io/rust-clippy/master/index.html#inverted_saturating_sub
 [`invisible_characters`]: https://rust-lang.github.io/rust-clippy/master/index.html#invisible_characters
+[`io_other_error`]: https://rust-lang.github.io/rust-clippy/master/index.html#io_other_error
 [`is_digit_ascii_radix`]: https://rust-lang.github.io/rust-clippy/master/index.html#is_digit_ascii_radix
 [`items_after_statements`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements
 [`items_after_test_module`]: https://rust-lang.github.io/rust-clippy/master/index.html#items_after_test_module

book/src/lint_configuration.md

@@ -759,6 +759,7 @@ The minimum rust version that the project supports. Defaults to the `rust-versio
 * [`from_over_into`](https://rust-lang.github.io/rust-clippy/master/index.html#from_over_into)
 * [`if_then_some_else_none`](https://rust-lang.github.io/rust-clippy/master/index.html#if_then_some_else_none)
 * [`index_refutable_slice`](https://rust-lang.github.io/rust-clippy/master/index.html#index_refutable_slice)
+* [`io_other_error`](https://rust-lang.github.io/rust-clippy/master/index.html#io_other_error)
 * [`iter_kv_map`](https://rust-lang.github.io/rust-clippy/master/index.html#iter_kv_map)
 * [`legacy_numeric_constants`](https://rust-lang.github.io/rust-clippy/master/index.html#legacy_numeric_constants)
 * [`lines_filter_map_ok`](https://rust-lang.github.io/rust-clippy/master/index.html#lines_filter_map_ok)

clippy_config/src/conf.rs

@@ -614,6 +614,7 @@ define_Conf! {
         from_over_into,
         if_then_some_else_none,
         index_refutable_slice,
+        io_other_error,
         iter_kv_map,
         legacy_numeric_constants,
         lines_filter_map_ok,

clippy_dev/src/new_lint.rs

@@ -1,11 +1,10 @@
 use crate::utils::{clippy_project_root, clippy_version};
 use indoc::{formatdoc, writedoc};
-use std::fmt;
 use std::fmt::Write as _;
 use std::fs::{self, OpenOptions};
 use std::io::prelude::*;
-use std::io::{self, ErrorKind};
 use std::path::{Path, PathBuf};
+use std::{fmt, io};
 
 struct LintData<'a> {
     pass: &'a str,
@@ -25,7 +24,7 @@ impl<T> Context for io::Result<T> {
             Ok(t) => Ok(t),
             Err(e) => {
                 let message = format!("{}: {e}", text.as_ref());
-                Err(io::Error::new(ErrorKind::Other, message))
+                Err(io::Error::other(message))
             },
         }
     }

clippy_lints/src/declared_lints.rs

@@ -400,6 +400,7 @@ pub static LINTS: &[&crate::LintInfo] = &[
     crate::methods::INEFFICIENT_TO_STRING_INFO,
     crate::methods::INSPECT_FOR_EACH_INFO,
     crate::methods::INTO_ITER_ON_REF_INFO,
+    crate::methods::IO_OTHER_ERROR_INFO,
     crate::methods::IS_DIGIT_ASCII_RADIX_INFO,
     crate::methods::ITERATOR_STEP_BY_ZERO_INFO,
     crate::methods::ITER_CLONED_COLLECT_INFO,

clippy_lints/src/manual_div_ceil.rs

@@ -59,7 +59,7 @@ impl_lint_pass!(ManualDivCeil => [MANUAL_DIV_CEIL]);
 
 impl<'tcx> LateLintPass<'tcx> for ManualDivCeil {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'_>) {
-        if !self.msrv.meets(msrvs::DIV_CEIL) {
+        if !self.msrv.meets(msrvs::MANUAL_DIV_CEIL) {
             return;
         }
 

clippy_lints/src/methods/io_other_error.rs

@@ -0,0 +1,37 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+use clippy_utils::msrvs::{IO_ERROR_OTHER, Msrv};
+use rustc_errors::Applicability;
+use rustc_hir::{Expr, ExprKind, QPath};
+use rustc_lint::LateContext;
+
+pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>, path: &Expr<'_>, args: &[Expr<'_>], msrv: &Msrv) {
+    if let [error_kind, error] = args
+        && !expr.span.from_expansion()
+        && !error_kind.span.from_expansion()
+        && clippy_utils::is_expr_path_def_path(cx, path, &clippy_utils::paths::IO_ERROR_NEW)
+        && clippy_utils::is_expr_path_def_path(
+            cx,
+            clippy_utils::expr_or_init(cx, error_kind),
+            &clippy_utils::paths::IO_ERRORKIND_OTHER,
+        )
+        && let ExprKind::Path(QPath::TypeRelative(_, new_segment)) = path.kind
+        && msrv.meets(IO_ERROR_OTHER)
+    {
+        span_lint_and_then(
+            cx,
+            super::IO_OTHER_ERROR,
+            expr.span,
+            "this can be `std::io::Error::other(_)`",
+            |diag| {
+                diag.multipart_suggestion_verbose(
+                    "use `std::io::Error::other`",
+                    vec![
+                        (new_segment.ident.span, "other".to_owned()),
+                        (error_kind.span.until(error.span), String::new()),
+                    ],
+                    Applicability::MachineApplicable,
+                );
+            },
+        );
+    }
+}

clippy_lints/src/methods/mod.rs

@@ -36,6 +36,7 @@ mod implicit_clone;
 mod inefficient_to_string;
 mod inspect_for_each;
 mod into_iter_on_ref;
+mod io_other_error;
 mod is_digit_ascii_radix;
 mod is_empty;
 mod iter_cloned_collect;
@@ -4461,6 +4462,28 @@ declare_clippy_lint! {
     "unnecessary `iter().any()` on slices that can be replaced with `contains()`"
 }
 
+declare_clippy_lint! {
+    /// This lint warns on calling `io::Error::new(..)` with a kind of
+    /// `io::ErrorKind::Other`.
+    ///
+    /// ### Why is this bad?
+    /// Since Rust 1.74, there's the `io::Error::other(_)` shortcut.
+    ///
+    /// ### Example
+    /// ```no_run
+    /// use std::io;
+    /// let _ = io::Error::new(io::ErrorKind::Other, "bad".to_string());
+    /// ```
+    /// Use instead:
+    /// ```no_run
+    /// let _ = std::io::Error::other("bad".to_string());
+    /// ```
+    #[clippy::version = "1.86.0"]
+    pub IO_OTHER_ERROR,
+    style,
+    "calling `std::io::Error::new(std::io::ErrorKind::Other, _)`"
+}
+
 #[expect(clippy::struct_excessive_bools)]
 pub struct Methods {
     avoid_breaking_exported_api: bool,
@@ -4637,6 +4660,7 @@ impl_lint_pass!(Methods => [
     RETURN_AND_THEN,
     UNBUFFERED_BYTES,
     MANUAL_CONTAINS,
+    IO_OTHER_ERROR,
 ]);
 
 /// Extracts a method call name, args, and `Span` of the method name.
@@ -4666,6 +4690,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
                 unnecessary_fallible_conversions::check_function(cx, expr, func);
                 manual_c_str_literals::check(cx, expr, func, args, &self.msrv);
                 useless_nonzero_new_unchecked::check(cx, expr, func, args, &self.msrv);
+                io_other_error::check(cx, expr, func, args, &self.msrv);
             },
             ExprKind::MethodCall(method_call, receiver, args, _) => {
                 let method_span = method_call.ident.span;

clippy_utils/src/msrvs.rs

@@ -27,8 +27,8 @@ msrv_aliases! {
     1,77,0 { C_STR_LITERALS }
     1,76,0 { PTR_FROM_REF, OPTION_RESULT_INSPECT }
     1,75,0 { OPTION_AS_SLICE }
-    1,74,0 { REPR_RUST }
-    1,73,0 { DIV_CEIL }
+    1,74,0 { REPR_RUST, IO_ERROR_OTHER }
+    1,73,0 { MANUAL_DIV_CEIL }
     1,71,0 { TUPLE_ARRAY_CONVERSIONS, BUILD_HASHER_HASH_ONE }
     1,70,0 { OPTION_RESULT_IS_VARIANT_AND, BINARY_HEAP_RETAIN }
     1,68,0 { PATH_MAIN_SEPARATOR_STR }

clippy_utils/src/paths.rs

@@ -29,6 +29,8 @@ pub const SYNTAX_CONTEXT: [&str; 3] = ["rustc_span", "hygiene", "SyntaxContext"]
 
 // Paths in `core`/`alloc`/`std`. This should be avoided and cleaned up by adding diagnostic items.
 pub const CHAR_IS_ASCII: [&str; 5] = ["core", "char", "methods", "<impl char>", "is_ascii"];
+pub const IO_ERROR_NEW: [&str; 5] = ["std", "io", "error", "Error", "new"];
+pub const IO_ERRORKIND_OTHER: [&str; 5] = ["std", "io", "error", "ErrorKind", "Other"];
 
 // Paths in clippy itself
 pub const MSRV: [&str; 3] = ["clippy_utils", "msrvs", "Msrv"];

tests/ui/format_args_unfixable.rs

@@ -2,7 +2,7 @@
 #![allow(unused)]
 #![allow(clippy::assertions_on_constants, clippy::eq_op, clippy::uninlined_format_args)]
 
-use std::io::{Error, ErrorKind, Write, stdout};
+use std::io::{Error, Write, stdout};
 use std::ops::Deref;
 use std::panic::Location;
 
@@ -20,7 +20,7 @@ macro_rules! my_other_macro {
 }
 
 fn main() {
-    let error = Error::new(ErrorKind::Other, "bad thing");
+    let error = Error::other("bad thing");
     let x = 'x';
 
     println!("error: {}", format!("something failed at {}", Location::caller()));
@@ -115,7 +115,7 @@ macro_rules! my_println2_args {
 }
 
 fn test2() {
-    let error = Error::new(ErrorKind::Other, "bad thing");
+    let error = Error::other("bad thing");
 
     // None of these should be linted without the config change
     my_println2!(true, "error: {}", format!("something failed at {}", Location::caller()));
@@ -145,7 +145,7 @@ macro_rules! usr_println {
 }
 
 fn user_format() {
-    let error = Error::new(ErrorKind::Other, "bad thing");
+    let error = Error::other("bad thing");
     let x = 'x';
 
     usr_println!(true, "error: {}", format!("boom at {}", Location::caller()));

tests/ui/io_other_error.fixed

@@ -0,0 +1,55 @@
+#![warn(clippy::io_other_error)]
+use std::fmt;
+
+#[derive(Debug)]
+struct E;
+
+impl std::error::Error for E {}
+impl fmt::Display for E {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str("E")
+    }
+}
+
+macro_rules! o {
+    {} => { std::io::ErrorKind::Other };
+}
+
+macro_rules! e {
+    { $kind:expr } => { std::io::Error::new($kind, E) };
+}
+
+fn main() {
+    let _err = std::io::Error::other(E);
+    //~^ ERROR: this can be `std::io::Error::other(_)`
+    let other = std::io::ErrorKind::Other;
+    let _err = std::io::Error::other(E);
+    //~^ ERROR: this can be `std::io::Error::other(_)`
+
+    // not other
+    let _err = std::io::Error::new(std::io::ErrorKind::TimedOut, E);
+
+    // from expansion
+    let _err = e!(other);
+    let _err = std::io::Error::new(o!(), E);
+    let _err = e!(o!());
+
+    paths::short();
+    under_msrv();
+}
+
+mod paths {
+    use std::io::{self, Error, ErrorKind};
+
+    pub fn short() {
+        let _err = Error::other(super::E);
+        //~^ ERROR: this can be `std::io::Error::other(_)`
+        let _err = io::Error::other(super::E);
+        //~^ ERROR: this can be `std::io::Error::other(_)`
+    }
+}
+
+#[clippy::msrv = "1.73"]
+fn under_msrv() {
+    let _err = std::io::Error::new(std::io::ErrorKind::Other, E);
+}

tests/ui/io_other_error.rs

@@ -0,0 +1,55 @@
+#![warn(clippy::io_other_error)]
+use std::fmt;
+
+#[derive(Debug)]
+struct E;
+
+impl std::error::Error for E {}
+impl fmt::Display for E {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.write_str("E")
+    }
+}
+
+macro_rules! o {
+    {} => { std::io::ErrorKind::Other };
+}
+
+macro_rules! e {
+    { $kind:expr } => { std::io::Error::new($kind, E) };
+}
+
+fn main() {
+    let _err = std::io::Error::new(std::io::ErrorKind::Other, E);
+    //~^ ERROR: this can be `std::io::Error::other(_)`
+    let other = std::io::ErrorKind::Other;
+    let _err = std::io::Error::new(other, E);
+    //~^ ERROR: this can be `std::io::Error::other(_)`
+
+    // not other
+    let _err = std::io::Error::new(std::io::ErrorKind::TimedOut, E);
+
+    // from expansion
+    let _err = e!(other);
+    let _err = std::io::Error::new(o!(), E);
+    let _err = e!(o!());
+
+    paths::short();
+    under_msrv();
+}
+
+mod paths {
+    use std::io::{self, Error, ErrorKind};
+
+    pub fn short() {
+        let _err = Error::new(ErrorKind::Other, super::E);
+        //~^ ERROR: this can be `std::io::Error::other(_)`
+        let _err = io::Error::new(io::ErrorKind::Other, super::E);
+        //~^ ERROR: this can be `std::io::Error::other(_)`
+    }
+}
+
+#[clippy::msrv = "1.73"]
+fn under_msrv() {
+    let _err = std::io::Error::new(std::io::ErrorKind::Other, E);
+}

tests/ui/io_other_error.stderr

@@ -0,0 +1,52 @@
+error: this can be `std::io::Error::other(_)`
+  --> tests/ui/io_other_error.rs:23:16
+   |
+LL |     let _err = std::io::Error::new(std::io::ErrorKind::Other, E);
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `-D clippy::io-other-error` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::io_other_error)]`
+help: use `std::io::Error::other`
+   |
+LL -     let _err = std::io::Error::new(std::io::ErrorKind::Other, E);
+LL +     let _err = std::io::Error::other(E);
+   |
+
+error: this can be `std::io::Error::other(_)`
+  --> tests/ui/io_other_error.rs:26:16
+   |
+LL |     let _err = std::io::Error::new(other, E);
+   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: use `std::io::Error::other`
+   |
+LL -     let _err = std::io::Error::new(other, E);
+LL +     let _err = std::io::Error::other(E);
+   |
+
+error: this can be `std::io::Error::other(_)`
+  --> tests/ui/io_other_error.rs:45:20
+   |
+LL |         let _err = Error::new(ErrorKind::Other, super::E);
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: use `std::io::Error::other`
+   |
+LL -         let _err = Error::new(ErrorKind::Other, super::E);
+LL +         let _err = Error::other(super::E);
+   |
+
+error: this can be `std::io::Error::other(_)`
+  --> tests/ui/io_other_error.rs:47:20
+   |
+LL |         let _err = io::Error::new(io::ErrorKind::Other, super::E);
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: use `std::io::Error::other`
+   |
+LL -         let _err = io::Error::new(io::ErrorKind::Other, super::E);
+LL +         let _err = io::Error::other(super::E);
+   |
+
+error: aborting due to 4 previous errors
+