Remove FIXME and make it retain old raw string hashes

Author: Centri3

clippy_lints/src/bare_dos_device_names.rs

@@ -2,14 +2,15 @@ use clippy_utils::{
     diagnostics::span_lint_and_then, get_parent_expr, is_from_proc_macro, match_def_path, path_res, paths::PATH_NEW,
     ty::is_type_diagnostic_item,
 };
-use rustc_ast::LitKind;
+use rustc_ast::{LitKind, StrStyle};
 use rustc_errors::Applicability;
 use rustc_hir::def_id::DefId;
 use rustc_hir::{Expr, ExprKind, QPath};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::{lint::in_external_macro, ty};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::{sym, Symbol};
+use std::borrow::Cow;
 
 declare_clippy_lint! {
     /// ### What it does
@@ -41,7 +42,7 @@ impl<'tcx> LateLintPass<'tcx> for BareDosDeviceNames {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
         if !in_external_macro(cx.sess(), expr.span)
             && let ExprKind::Lit(arg) = expr.kind
-            && let LitKind::Str(str_sym, _) = arg.node
+            && let LitKind::Str(str_sym, str_style) = arg.node
             && matches!(
                 &*str_sym.as_str().to_ascii_lowercase(),
                 "aux"
@@ -86,20 +87,26 @@ impl<'tcx> LateLintPass<'tcx> for BareDosDeviceNames {
                 expr.span,
                 "this path refers to a DOS device",
                 |diag| {
+                    // Keep `r###` and `###`
+                    let (prefix, hashes) = if let StrStyle::Raw(num) = str_style {
+                        (Cow::Borrowed("r"), "#".repeat(num as usize).into())
+                    } else {
+                        (Cow::Borrowed(""), Cow::Borrowed(""))
+                    };
+
                     // Suggest making current behavior explicit
                     diag.span_suggestion_verbose(
                         expr.span,
-                        "if this is intended, try",
-                        // FIXME: I have zero clue why it normalizes this. `\` -> `/`
-                        format!(r#"r"\\.\{str_sym}"\"#),
+                        "if this is intended, use",
+                        format!(r#"r{hashes}"\\.\{str_sym}"{hashes}"#),
                         Applicability::MaybeIncorrect,
                     );
 
                     // Suggest making the code refer to a file or folder in the current directory
                     diag.span_suggestion_verbose(
                         expr.span,
-                        "if this was intended to point to a file or folder, try",
-                        format!("\"./{str_sym}\""),
+                        "if this was intended to point to a file or folder, use",
+                        format!(r#"{prefix}{hashes}"./{str_sym}"{hashes}"#),
                         Applicability::MaybeIncorrect,
                     );
                 }

tests/ui/bare_dos_device_names.rs

@@ -1,5 +1,5 @@
 //@aux-build:proc_macros.rs:proc-macro
-#![allow(clippy::no_effect, unused)]
+#![allow(clippy::needless_raw_string_hashes, clippy::no_effect, unused)]
 #![warn(clippy::bare_dos_device_names)]
 
 #[macro_use]
@@ -20,6 +20,9 @@ fn main() {
     b("conin$");
     File::open("conin$");
     std::path::PathBuf::from("a");
+    // Keep raw string
+    Path::new(r##"aux"##);
+    // Don't lint
     PathBuf::from("a");
     Path::new("a");
     external! {

tests/ui/bare_dos_device_names.stderr

@@ -5,11 +5,11 @@ LL |     a("con");
    |       ^^^^^
    |
    = note: `-D clippy::bare-dos-device-names` implied by `-D warnings`
-help: if this is intended, try
+help: if this is intended, use
    |
-LL |     a(r"//./con"/);
-   |       ~~~~~~~~~~~
-help: if this was intended to point to a file or folder, try
+LL |     a(r"//./con");
+   |       ~~~~~~~~~~
+help: if this was intended to point to a file or folder, use
    |
 LL |     a("./con");
    |       ~~~~~~~
@@ -20,11 +20,11 @@ error: this path refers to a DOS device
 LL |     b("conin$");
    |       ^^^^^^^^
    |
-help: if this is intended, try
+help: if this is intended, use
    |
-LL |     b(r"//./conin$"/);
-   |       ~~~~~~~~~~~~~~
-help: if this was intended to point to a file or folder, try
+LL |     b(r"//./conin$");
+   |       ~~~~~~~~~~~~~
+help: if this was intended to point to a file or folder, use
    |
 LL |     b("./conin$");
    |       ~~~~~~~~~~
@@ -35,14 +35,29 @@ error: this path refers to a DOS device
 LL |     File::open("conin$");
    |                ^^^^^^^^
    |
-help: if this is intended, try
+help: if this is intended, use
    |
-LL |     File::open(r"//./conin$"/);
-   |                ~~~~~~~~~~~~~~
-help: if this was intended to point to a file or folder, try
+LL |     File::open(r"//./conin$");
+   |                ~~~~~~~~~~~~~
+help: if this was intended to point to a file or folder, use
    |
 LL |     File::open("./conin$");
    |                ~~~~~~~~~~
 
-error: aborting due to 3 previous errors
+error: this path refers to a DOS device
+  --> $DIR/bare_dos_device_names.rs:24:15
+   |
+LL |     Path::new(r##"aux"##);
+   |               ^^^^^^^^^^
+   |
+help: if this is intended, use
+   |
+LL |     Path::new(r##"//./aux"##);
+   |               ~~~~~~~~~~~~~~
+help: if this was intended to point to a file or folder, use
+   |
+LL |     Path::new(r##"./aux"##);
+   |               ~~~~~~~~~~~~
+
+error: aborting due to 4 previous errors