Rollup merge of #111543 - Urgau:uplift_invalid_utf8_in_unchecked, r=WaffleLapkin

Uplift `clippy::invalid_utf8_in_unchecked` lint

This PR aims at uplifting the `clippy::invalid_utf8_in_unchecked` lint into two lints.

## `invalid_from_utf8_unchecked`

(deny-by-default)

The `invalid_from_utf8_unchecked` lint checks for calls to `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut` with an invalid UTF-8 literal.

### Example

```rust
unsafe {
    std::str::from_utf8_unchecked(b"cl\x82ippy");
}
```

### Explanation

Creating such a `str` would result in undefined behavior as per documentation for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.

## `invalid_from_utf8`

(warn-by-default)

The `invalid_from_utf8` lint checks for calls to `std::str::from_utf8` and `std::str::from_utf8_mut` with an invalid UTF-8 literal.

### Example

```rust
std::str::from_utf8(b"ru\x82st");
```

### Explanation

Trying to create such a `str` would always return an error as per documentation for `std::str::from_utf8` and `std::str::from_utf8_mut`.

-----

Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751

````@rustbot```` label: +I-lang-nominated
r? compiler

-----

For Clippy:

changelog: Moves: Uplifted `clippy::invalid_utf8_in_unchecked` into rustc

19 files changed, 423 insertions, 168 deletions

diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index d34a3afcba5..e707ac41a05 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -304,6 +304,14 @@ lint_improper_ctypes_union_layout_help = consider adding a `#[repr(C)]` or `#[re
 lint_improper_ctypes_union_layout_reason = this union has unspecified layout
 lint_improper_ctypes_union_non_exhaustive = this union is non-exhaustive
 
+# FIXME: we should ordinalize $valid_up_to when we add support for doing so
+lint_invalid_from_utf8_checked = calls to `{$method}` with a invalid literal always return an error
+    .label = the literal was valid UTF-8 up to the {$valid_up_to} bytes
+
+# FIXME: we should ordinalize $valid_up_to when we add support for doing so
+lint_invalid_from_utf8_unchecked = calls to `{$method}` with a invalid literal are undefined behavior
+    .label = the literal was valid UTF-8 up to the {$valid_up_to} bytes
+
 lint_lintpass_by_hand = implementing `LintPass` by hand
     .help = try using `declare_lint_pass!` or `impl_lint_pass!` instead
 
diff --git a/compiler/rustc_lint/src/invalid_from_utf8.rs b/compiler/rustc_lint/src/invalid_from_utf8.rs
new file mode 100644
index 00000000000..3291286ad67
--- /dev/null
+++ b/compiler/rustc_lint/src/invalid_from_utf8.rs
@@ -0,0 +1,118 @@
+use std::str::Utf8Error;
+
+use rustc_ast::{BorrowKind, LitKind};
+use rustc_hir::{Expr, ExprKind};
+use rustc_span::source_map::Spanned;
+use rustc_span::sym;
+
+use crate::lints::InvalidFromUtf8Diag;
+use crate::{LateContext, LateLintPass, LintContext};
+
+declare_lint! {
+    /// The `invalid_from_utf8_unchecked` lint checks for calls to
+    /// `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`
+    /// with an invalid UTF-8 literal.
+    ///
+    /// ### Example
+    ///
+    /// ```rust,compile_fail
+    /// # #[allow(unused)]
+    /// unsafe {
+    ///     std::str::from_utf8_unchecked(b"Ru\x82st");
+    /// }
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Creating such a `str` would result in undefined behavior as per documentation
+    /// for `std::str::from_utf8_unchecked` and `std::str::from_utf8_unchecked_mut`.
+    pub INVALID_FROM_UTF8_UNCHECKED,
+    Deny,
+    "using a non UTF-8 literal in `std::str::from_utf8_unchecked`"
+}
+
+declare_lint! {
+    /// The `invalid_from_utf8` lint checks for calls to
+    /// `std::str::from_utf8` and `std::str::from_utf8_mut`
+    /// with an invalid UTF-8 literal.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// # #[allow(unused)]
+    /// std::str::from_utf8(b"Ru\x82st");
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// Trying to create such a `str` would always return an error as per documentation
+    /// for `std::str::from_utf8` and `std::str::from_utf8_mut`.
+    pub INVALID_FROM_UTF8,
+    Warn,
+    "using a non UTF-8 literal in `std::str::from_utf8`"
+}
+
+declare_lint_pass!(InvalidFromUtf8 => [INVALID_FROM_UTF8_UNCHECKED, INVALID_FROM_UTF8]);
+
+impl<'tcx> LateLintPass<'tcx> for InvalidFromUtf8 {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+        if let ExprKind::Call(path, [arg]) = expr.kind
+            && let ExprKind::Path(ref qpath) = path.kind
+            && let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
+            && let Some(diag_item) = cx.tcx.get_diagnostic_name(def_id)
+            && [sym::str_from_utf8, sym::str_from_utf8_mut,
+                sym::str_from_utf8_unchecked, sym::str_from_utf8_unchecked_mut].contains(&diag_item)
+        {
+            let lint = |utf8_error: Utf8Error| {
+                let label = arg.span;
+                let method = diag_item.as_str().strip_prefix("str_").unwrap();
+                let method = format!("std::str::{method}");
+                let valid_up_to = utf8_error.valid_up_to();
+                let is_unchecked_variant = diag_item.as_str().contains("unchecked");
+
+                cx.emit_spanned_lint(
+                    if is_unchecked_variant { INVALID_FROM_UTF8_UNCHECKED } else { INVALID_FROM_UTF8 },
+                    expr.span,
+                    if is_unchecked_variant {
+                        InvalidFromUtf8Diag::Unchecked { method,  valid_up_to, label }
+                    } else {
+                        InvalidFromUtf8Diag::Checked { method,  valid_up_to, label }
+                    }
+                )
+            };
+
+            match &arg.kind {
+                ExprKind::Lit(Spanned { node: lit, .. }) => {
+                    if let LitKind::ByteStr(bytes, _) = &lit
+                        && let Err(utf8_error) = std::str::from_utf8(bytes)
+                    {
+                        lint(utf8_error);
+                    }
+                },
+                ExprKind::AddrOf(BorrowKind::Ref, _, Expr { kind: ExprKind::Array(args), .. }) => {
+                    let elements = args.iter().map(|e|{
+                        match &e.kind {
+                            ExprKind::Lit(Spanned { node: lit, .. }) => match lit {
+                                LitKind::Byte(b) => Some(*b),
+                                LitKind::Int(b, _) => Some(*b as u8),
+                                _ => None
+                            }
+                            _ => None
+                        }
+                    }).collect::<Option<Vec<_>>>();
+
+                    if let Some(elements) = elements
+                        && let Err(utf8_error) = std::str::from_utf8(&elements)
+                    {
+                        lint(utf8_error);
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+}
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index dfddfe09ab3..c62109b2986 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -60,6 +60,7 @@ mod expect;
 mod for_loops_over_fallibles;
 pub mod hidden_unicode_codepoints;
 mod internal;
+mod invalid_from_utf8;
 mod late;
 mod let_underscore;
 mod levels;
@@ -102,6 +103,7 @@ use enum_intrinsics_non_enums::EnumIntrinsicsNonEnums;
 use for_loops_over_fallibles::*;
 use hidden_unicode_codepoints::*;
 use internal::*;
+use invalid_from_utf8::*;
 use let_underscore::*;
 use map_unit_fn::*;
 use methods::*;
@@ -207,6 +209,7 @@ late_lint_methods!(
             HardwiredLints: HardwiredLints,
             ImproperCTypesDeclarations: ImproperCTypesDeclarations,
             ImproperCTypesDefinitions: ImproperCTypesDefinitions,
+            InvalidFromUtf8: InvalidFromUtf8,
             VariantSizeDifferences: VariantSizeDifferences,
             BoxPointers: BoxPointers,
             PathStatements: PathStatements,
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index 6b4d01551ae..746abebeb37 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -699,6 +699,25 @@ pub struct ForgetCopyDiag<'a> {
     pub label: Span,
 }
 
+// invalid_from_utf8.rs
+#[derive(LintDiagnostic)]
+pub enum InvalidFromUtf8Diag {
+    #[diag(lint_invalid_from_utf8_unchecked)]
+    Unchecked {
+        method: String,
+        valid_up_to: usize,
+        #[label]
+        label: Span,
+    },
+    #[diag(lint_invalid_from_utf8_checked)]
+    Checked {
+        method: String,
+        valid_up_to: usize,
+        #[label]
+        label: Span,
+    },
+}
+
 // hidden_unicode_codepoints.rs
 #[derive(LintDiagnostic)]
 #[diag(lint_hidden_unicode_codepoints)]
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 874d578fe1d..1185563ea80 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1454,6 +1454,10 @@ symbols! {
         stop_after_dataflow,
         store,
         str,
+        str_from_utf8,
+        str_from_utf8_mut,
+        str_from_utf8_unchecked,
+        str_from_utf8_unchecked_mut,
         str_split_whitespace,
         str_trim,
         str_trim_end,
diff --git a/library/alloc/tests/str.rs b/library/alloc/tests/str.rs
index c1dbbde08b6..0ba5d088f61 100644
--- a/library/alloc/tests/str.rs
+++ b/library/alloc/tests/str.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(not(bootstrap), allow(invalid_from_utf8))]
+
 use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 use std::cmp::Ordering::{Equal, Greater, Less};
diff --git a/library/core/src/str/converts.rs b/library/core/src/str/converts.rs
index 5f8748206d7..0f23cf7ae23 100644
--- a/library/core/src/str/converts.rs
+++ b/library/core/src/str/converts.rs
@@ -84,6 +84,7 @@ use super::Utf8Error;
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_stable(feature = "const_str_from_utf8_shared", since = "1.63.0")]
 #[rustc_allow_const_fn_unstable(str_internals)]
+#[rustc_diagnostic_item = "str_from_utf8"]
 pub const fn from_utf8(v: &[u8]) -> Result<&str, Utf8Error> {
     // FIXME: This should use `?` again, once it's `const`
     match run_utf8_validation(v) {
@@ -127,6 +128,7 @@ pub const fn from_utf8(v: &[u8]) -> Result<&str, Utf8Error> {
 /// errors that can be returned.
 #[stable(feature = "str_mut_extras", since = "1.20.0")]
 #[rustc_const_unstable(feature = "const_str_from_utf8", issue = "91006")]
+#[rustc_diagnostic_item = "str_from_utf8_mut"]
 pub const fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> {
     // This should use `?` again, once it's `const`
     match run_utf8_validation(v) {
@@ -167,6 +169,7 @@ pub const fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> {
 #[must_use]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_stable(feature = "const_str_from_utf8_unchecked", since = "1.55.0")]
+#[rustc_diagnostic_item = "str_from_utf8_unchecked"]
 pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
     // SAFETY: the caller must guarantee that the bytes `v` are valid UTF-8.
     // Also relies on `&str` and `&[u8]` having the same layout.
@@ -194,6 +197,7 @@ pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
 #[must_use]
 #[stable(feature = "str_mut_extras", since = "1.20.0")]
 #[rustc_const_unstable(feature = "const_str_from_utf8_unchecked_mut", issue = "91005")]
+#[rustc_diagnostic_item = "str_from_utf8_unchecked_mut"]
 pub const unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str {
     // SAFETY: the caller must guarantee that the bytes `v`
     // are valid UTF-8, thus the cast to `*mut str` is safe.
diff --git a/src/tools/clippy/clippy_lints/src/declared_lints.rs b/src/tools/clippy/clippy_lints/src/declared_lints.rs
index 423eee47742..0ae95b045e0 100644
--- a/src/tools/clippy/clippy_lints/src/declared_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/declared_lints.rs
@@ -212,7 +212,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
     crate::instant_subtraction::UNCHECKED_DURATION_SUBTRACTION_INFO,
     crate::int_plus_one::INT_PLUS_ONE_INFO,
     crate::invalid_upcast_comparisons::INVALID_UPCAST_COMPARISONS_INFO,
-    crate::invalid_utf8_in_unchecked::INVALID_UTF8_IN_UNCHECKED_INFO,
     crate::items_after_statements::ITEMS_AFTER_STATEMENTS_INFO,
     crate::items_after_test_module::ITEMS_AFTER_TEST_MODULE_INFO,
     crate::iter_not_returning_iterator::ITER_NOT_RETURNING_ITERATOR_INFO,
diff --git a/src/tools/clippy/clippy_lints/src/invalid_utf8_in_unchecked.rs b/src/tools/clippy/clippy_lints/src/invalid_utf8_in_unchecked.rs
deleted file mode 100644
index 6a4861747d2..00000000000
--- a/src/tools/clippy/clippy_lints/src/invalid_utf8_in_unchecked.rs
+++ /dev/null
@@ -1,74 +0,0 @@
-use clippy_utils::diagnostics::span_lint;
-use clippy_utils::{match_function_call, paths};
-use rustc_ast::{BorrowKind, LitKind};
-use rustc_hir::{Expr, ExprKind};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::source_map::Spanned;
-use rustc_span::Span;
-
-declare_clippy_lint! {
-    /// ### What it does
-    /// Checks for `std::str::from_utf8_unchecked` with an invalid UTF-8 literal
-    ///
-    /// ### Why is this bad?
-    /// Creating such a `str` would result in undefined behavior
-    ///
-    /// ### Example
-    /// ```rust
-    /// # #[allow(unused)]
-    /// unsafe {
-    ///     std::str::from_utf8_unchecked(b"cl\x82ippy");
-    /// }
-    /// ```
-    #[clippy::version = "1.64.0"]
-    pub INVALID_UTF8_IN_UNCHECKED,
-    correctness,
-    "using a non UTF-8 literal in `std::std::from_utf8_unchecked`"
-}
-declare_lint_pass!(InvalidUtf8InUnchecked => [INVALID_UTF8_IN_UNCHECKED]);
-
-impl<'tcx> LateLintPass<'tcx> for InvalidUtf8InUnchecked {
-    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
-        if let Some([arg]) = match_function_call(cx, expr, &paths::STR_FROM_UTF8_UNCHECKED) {
-            match &arg.kind {
-                ExprKind::Lit(Spanned { node: lit, .. }) => {
-                    if let LitKind::ByteStr(bytes, _) = &lit
-                        && std::str::from_utf8(bytes).is_err()
-                    {
-                        lint(cx, expr.span);
-                    }
-                },
-                ExprKind::AddrOf(BorrowKind::Ref, _, Expr { kind: ExprKind::Array(args), .. }) => {
-                    let elements = args.iter().map(|e|{
-                        match &e.kind {
-                            ExprKind::Lit(Spanned { node: lit, .. }) => match lit {
-                                LitKind::Byte(b) => Some(*b),
-                                #[allow(clippy::cast_possible_truncation)]
-                                LitKind::Int(b, _) => Some(*b as u8),
-                                _ => None
-                            }
-                            _ => None
-                        }
-                    }).collect::<Option<Vec<_>>>();
-
-                    if let Some(elements) = elements
-                        && std::str::from_utf8(&elements).is_err()
-                    {
-                        lint(cx, expr.span);
-                    }
-                }
-                _ => {}
-            }
-        }
-    }
-}
-
-fn lint(cx: &LateContext<'_>, span: Span) {
-    span_lint(
-        cx,
-        INVALID_UTF8_IN_UNCHECKED,
-        span,
-        "non UTF-8 literal in `std::str::from_utf8_unchecked`",
-    );
-}
diff --git a/src/tools/clippy/clippy_lints/src/lib.rs b/src/tools/clippy/clippy_lints/src/lib.rs
index b442a4ac5f6..fcca595c2bc 100644
--- a/src/tools/clippy/clippy_lints/src/lib.rs
+++ b/src/tools/clippy/clippy_lints/src/lib.rs
@@ -157,7 +157,6 @@ mod inline_fn_without_body;
 mod instant_subtraction;
 mod int_plus_one;
 mod invalid_upcast_comparisons;
-mod invalid_utf8_in_unchecked;
 mod items_after_statements;
 mod items_after_test_module;
 mod iter_not_returning_iterator;
@@ -937,7 +936,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(move |_| Box::new(manual_retain::ManualRetain::new(msrv())));
     let verbose_bit_mask_threshold = conf.verbose_bit_mask_threshold;
     store.register_late_pass(move |_| Box::new(operators::Operators::new(verbose_bit_mask_threshold)));
-    store.register_late_pass(|_| Box::new(invalid_utf8_in_unchecked::InvalidUtf8InUnchecked));
     store.register_late_pass(|_| Box::<std_instead_of_core::StdReexports>::default());
     store.register_late_pass(move |_| Box::new(instant_subtraction::InstantSubtraction::new(msrv())));
     store.register_late_pass(|_| Box::new(partialeq_to_none::PartialeqToNone));
diff --git a/src/tools/clippy/clippy_lints/src/renamed_lints.rs b/src/tools/clippy/clippy_lints/src/renamed_lints.rs
index b0db56bb417..7c2a100efda 100644
--- a/src/tools/clippy/clippy_lints/src/renamed_lints.rs
+++ b/src/tools/clippy/clippy_lints/src/renamed_lints.rs
@@ -43,6 +43,7 @@ pub static RENAMED_LINTS: &[(&str, &str)] = &[
     ("clippy::into_iter_on_array", "array_into_iter"),
     ("clippy::invalid_atomic_ordering", "invalid_atomic_ordering"),
     ("clippy::invalid_ref", "invalid_value"),
+    ("clippy::invalid_utf8_in_unchecked", "invalid_from_utf8_unchecked"),
     ("clippy::let_underscore_drop", "let_underscore_drop"),
     ("clippy::mem_discriminant_non_enum", "enum_intrinsics_non_enums"),
     ("clippy::panic_params", "non_fmt_panics"),
diff --git a/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.rs b/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.rs
deleted file mode 100644
index 3dc096d3197..00000000000
--- a/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-#![warn(clippy::invalid_utf8_in_unchecked)]
-
-fn main() {
-    // Valid
-    unsafe {
-        std::str::from_utf8_unchecked(&[99, 108, 105, 112, 112, 121]);
-        std::str::from_utf8_unchecked(&[b'c', b'l', b'i', b'p', b'p', b'y']);
-        std::str::from_utf8_unchecked(b"clippy");
-
-        let x = 0xA0;
-        std::str::from_utf8_unchecked(&[0xC0, x]);
-    }
-
-    // Invalid
-    unsafe {
-        std::str::from_utf8_unchecked(&[99, 108, 130, 105, 112, 112, 121]);
-        std::str::from_utf8_unchecked(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
-        std::str::from_utf8_unchecked(b"cl\x82ippy");
-    }
-}
diff --git a/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.stderr b/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.stderr
deleted file mode 100644
index c89cd2758ee..00000000000
--- a/src/tools/clippy/tests/ui/invalid_utf8_in_unchecked.stderr
+++ /dev/null
@@ -1,22 +0,0 @@
-error: non UTF-8 literal in `std::str::from_utf8_unchecked`
-  --> $DIR/invalid_utf8_in_unchecked.rs:16:9
-   |
-LL |         std::str::from_utf8_unchecked(&[99, 108, 130, 105, 112, 112, 121]);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: `-D clippy::invalid-utf8-in-unchecked` implied by `-D warnings`
-
-error: non UTF-8 literal in `std::str::from_utf8_unchecked`
-  --> $DIR/invalid_utf8_in_unchecked.rs:17:9
-   |
-LL |         std::str::from_utf8_unchecked(&[b'c', b'l', b'/x82', b'i', b'p', b'p', b'y']);
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: non UTF-8 literal in `std::str::from_utf8_unchecked`
-  --> $DIR/invalid_utf8_in_unchecked.rs:18:9
-   |
-LL |         std::str::from_utf8_unchecked(b"cl/x82ippy");
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
-
diff --git a/src/tools/clippy/tests/ui/rename.fixed b/src/tools/clippy/tests/ui/rename.fixed
index dfe45dec8a7..53ac65473b8 100644
--- a/src/tools/clippy/tests/ui/rename.fixed
+++ b/src/tools/clippy/tests/ui/rename.fixed
@@ -38,6 +38,7 @@
 #![allow(array_into_iter)]
 #![allow(invalid_atomic_ordering)]
 #![allow(invalid_value)]
+#![allow(invalid_from_utf8_unchecked)]
 #![allow(let_underscore_drop)]
 #![allow(enum_intrinsics_non_enums)]
 #![allow(non_fmt_panics)]
@@ -87,6 +88,7 @@
 #![warn(array_into_iter)]
 #![warn(invalid_atomic_ordering)]
 #![warn(invalid_value)]
+#![warn(invalid_from_utf8_unchecked)]
 #![warn(let_underscore_drop)]
 #![warn(enum_intrinsics_non_enums)]
 #![warn(non_fmt_panics)]
diff --git a/src/tools/clippy/tests/ui/rename.rs b/src/tools/clippy/tests/ui/rename.rs
index ce8eca5a308..722c0b3eb27 100644
--- a/src/tools/clippy/tests/ui/rename.rs
+++ b/src/tools/clippy/tests/ui/rename.rs
@@ -38,6 +38,7 @@
 #![allow(array_into_iter)]
 #![allow(invalid_atomic_ordering)]
 #![allow(invalid_value)]
+#![allow(invalid_from_utf8_unchecked)]
 #![allow(let_underscore_drop)]
 #![allow(enum_intrinsics_non_enums)]
 #![allow(non_fmt_panics)]
@@ -87,6 +88,7 @@
 #![warn(clippy::into_iter_on_array)]
 #![warn(clippy::invalid_atomic_ordering)]
 #![warn(clippy::invalid_ref)]
+#![warn(clippy::invalid_utf8_in_unchecked)]
 #![warn(clippy::let_underscore_drop)]
 #![warn(clippy::mem_discriminant_non_enum)]
 #![warn(clippy::panic_params)]
diff --git a/src/tools/clippy/tests/ui/rename.stderr b/src/tools/clippy/tests/ui/rename.stderr
index 3fca60aa2eb..1ff83917660 100644
--- a/src/tools/clippy/tests/ui/rename.stderr
+++ b/src/tools/clippy/tests/ui/rename.stderr
@@ -1,5 +1,5 @@
 error: lint `clippy::almost_complete_letter_range` has been renamed to `clippy::almost_complete_range`
-  --> $DIR/rename.rs:49:9
+  --> $DIR/rename.rs:50:9
    |
 LL | #![warn(clippy::almost_complete_letter_range)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::almost_complete_range`
@@ -7,286 +7,292 @@ LL | #![warn(clippy::almost_complete_letter_range)]
    = note: `-D renamed-and-removed-lints` implied by `-D warnings`
 
 error: lint `clippy::blacklisted_name` has been renamed to `clippy::disallowed_names`
-  --> $DIR/rename.rs:50:9
+  --> $DIR/rename.rs:51:9
    |
 LL | #![warn(clippy::blacklisted_name)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_names`
 
 error: lint `clippy::block_in_if_condition_expr` has been renamed to `clippy::blocks_in_if_conditions`
-  --> $DIR/rename.rs:51:9
+  --> $DIR/rename.rs:52:9
    |
 LL | #![warn(clippy::block_in_if_condition_expr)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::blocks_in_if_conditions`
 
 error: lint `clippy::block_in_if_condition_stmt` has been renamed to `clippy::blocks_in_if_conditions`
-  --> $DIR/rename.rs:52:9
+  --> $DIR/rename.rs:53:9
    |
 LL | #![warn(clippy::block_in_if_condition_stmt)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::blocks_in_if_conditions`
 
 error: lint `clippy::box_vec` has been renamed to `clippy::box_collection`
-  --> $DIR/rename.rs:53:9
+  --> $DIR/rename.rs:54:9
    |
 LL | #![warn(clippy::box_vec)]
    |         ^^^^^^^^^^^^^^^ help: use the new name: `clippy::box_collection`
 
 error: lint `clippy::const_static_lifetime` has been renamed to `clippy::redundant_static_lifetimes`
-  --> $DIR/rename.rs:54:9
+  --> $DIR/rename.rs:55:9
    |
 LL | #![warn(clippy::const_static_lifetime)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::redundant_static_lifetimes`
 
 error: lint `clippy::cyclomatic_complexity` has been renamed to `clippy::cognitive_complexity`
-  --> $DIR/rename.rs:55:9
+  --> $DIR/rename.rs:56:9
    |
 LL | #![warn(clippy::cyclomatic_complexity)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::cognitive_complexity`
 
 error: lint `clippy::derive_hash_xor_eq` has been renamed to `clippy::derived_hash_with_manual_eq`
-  --> $DIR/rename.rs:56:9
+  --> $DIR/rename.rs:57:9
    |
 LL | #![warn(clippy::derive_hash_xor_eq)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::derived_hash_with_manual_eq`
 
 error: lint `clippy::disallowed_method` has been renamed to `clippy::disallowed_methods`
-  --> $DIR/rename.rs:57:9
+  --> $DIR/rename.rs:58:9
    |
 LL | #![warn(clippy::disallowed_method)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_methods`
 
 error: lint `clippy::disallowed_type` has been renamed to `clippy::disallowed_types`
-  --> $DIR/rename.rs:58:9
+  --> $DIR/rename.rs:59:9
    |
 LL | #![warn(clippy::disallowed_type)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::disallowed_types`
 
 error: lint `clippy::eval_order_dependence` has been renamed to `clippy::mixed_read_write_in_expression`
-  --> $DIR/rename.rs:59:9
+  --> $DIR/rename.rs:60:9
    |
 LL | #![warn(clippy::eval_order_dependence)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::mixed_read_write_in_expression`
 
 error: lint `clippy::identity_conversion` has been renamed to `clippy::useless_conversion`
-  --> $DIR/rename.rs:60:9
+  --> $DIR/rename.rs:61:9
    |
 LL | #![warn(clippy::identity_conversion)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::useless_conversion`
 
 error: lint `clippy::if_let_some_result` has been renamed to `clippy::match_result_ok`
-  --> $DIR/rename.rs:61:9
+  --> $DIR/rename.rs:62:9
    |
 LL | #![warn(clippy::if_let_some_result)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::match_result_ok`
 
 error: lint `clippy::integer_arithmetic` has been renamed to `clippy::arithmetic_side_effects`
-  --> $DIR/rename.rs:62:9
+  --> $DIR/rename.rs:63:9
    |
 LL | #![warn(clippy::integer_arithmetic)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::arithmetic_side_effects`
 
 error: lint `clippy::logic_bug` has been renamed to `clippy::overly_complex_bool_expr`
-  --> $DIR/rename.rs:63:9
+  --> $DIR/rename.rs:64:9
    |
 LL | #![warn(clippy::logic_bug)]
    |         ^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::overly_complex_bool_expr`
 
 error: lint `clippy::new_without_default_derive` has been renamed to `clippy::new_without_default`
-  --> $DIR/rename.rs:64:9
+  --> $DIR/rename.rs:65:9
    |
 LL | #![warn(clippy::new_without_default_derive)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::new_without_default`
 
 error: lint `clippy::option_and_then_some` has been renamed to `clippy::bind_instead_of_map`
-  --> $DIR/rename.rs:65:9
+  --> $DIR/rename.rs:66:9
    |
 LL | #![warn(clippy::option_and_then_some)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::bind_instead_of_map`
 
 error: lint `clippy::option_expect_used` has been renamed to `clippy::expect_used`
-  --> $DIR/rename.rs:66:9
+  --> $DIR/rename.rs:67:9
    |
 LL | #![warn(clippy::option_expect_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used`
 
 error: lint `clippy::option_map_unwrap_or` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:67:9
+  --> $DIR/rename.rs:68:9
    |
 LL | #![warn(clippy::option_map_unwrap_or)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::option_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:68:9
+  --> $DIR/rename.rs:69:9
    |
 LL | #![warn(clippy::option_map_unwrap_or_else)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::option_unwrap_used` has been renamed to `clippy::unwrap_used`
-  --> $DIR/rename.rs:69:9
+  --> $DIR/rename.rs:70:9
    |
 LL | #![warn(clippy::option_unwrap_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used`
 
 error: lint `clippy::ref_in_deref` has been renamed to `clippy::needless_borrow`
-  --> $DIR/rename.rs:70:9
+  --> $DIR/rename.rs:71:9
    |
 LL | #![warn(clippy::ref_in_deref)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::needless_borrow`
 
 error: lint `clippy::result_expect_used` has been renamed to `clippy::expect_used`
-  --> $DIR/rename.rs:71:9
+  --> $DIR/rename.rs:72:9
    |
 LL | #![warn(clippy::result_expect_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::expect_used`
 
 error: lint `clippy::result_map_unwrap_or_else` has been renamed to `clippy::map_unwrap_or`
-  --> $DIR/rename.rs:72:9
+  --> $DIR/rename.rs:73:9
    |
 LL | #![warn(clippy::result_map_unwrap_or_else)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::map_unwrap_or`
 
 error: lint `clippy::result_unwrap_used` has been renamed to `clippy::unwrap_used`
-  --> $DIR/rename.rs:73:9
+  --> $DIR/rename.rs:74:9
    |
 LL | #![warn(clippy::result_unwrap_used)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::unwrap_used`
 
 error: lint `clippy::single_char_push_str` has been renamed to `clippy::single_char_add_str`
-  --> $DIR/rename.rs:74:9
+  --> $DIR/rename.rs:75:9
    |
 LL | #![warn(clippy::single_char_push_str)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::single_char_add_str`
 
 error: lint `clippy::stutter` has been renamed to `clippy::module_name_repetitions`
-  --> $DIR/rename.rs:75:9
+  --> $DIR/rename.rs:76:9
    |
 LL | #![warn(clippy::stutter)]
    |         ^^^^^^^^^^^^^^^ help: use the new name: `clippy::module_name_repetitions`
 
 error: lint `clippy::to_string_in_display` has been renamed to `clippy::recursive_format_impl`
-  --> $DIR/rename.rs:76:9
+  --> $DIR/rename.rs:77:9
    |
 LL | #![warn(clippy::to_string_in_display)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::recursive_format_impl`
 
 error: lint `clippy::zero_width_space` has been renamed to `clippy::invisible_characters`
-  --> $DIR/rename.rs:77:9
+  --> $DIR/rename.rs:78:9
    |
 LL | #![warn(clippy::zero_width_space)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `clippy::invisible_characters`
 
 error: lint `clippy::clone_double_ref` has been renamed to `suspicious_double_ref_op`
-  --> $DIR/rename.rs:78:9
+  --> $DIR/rename.rs:79:9
    |
 LL | #![warn(clippy::clone_double_ref)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `suspicious_double_ref_op`
 
 error: lint `clippy::drop_bounds` has been renamed to `drop_bounds`
-  --> $DIR/rename.rs:79:9
+  --> $DIR/rename.rs:80:9
    |
 LL | #![warn(clippy::drop_bounds)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `drop_bounds`
 
 error: lint `clippy::drop_copy` has been renamed to `dropping_copy_types`
-  --> $DIR/rename.rs:80:9
+  --> $DIR/rename.rs:81:9
    |
 LL | #![warn(clippy::drop_copy)]
    |         ^^^^^^^^^^^^^^^^^ help: use the new name: `dropping_copy_types`
 
 error: lint `clippy::drop_ref` has been renamed to `dropping_references`
-  --> $DIR/rename.rs:81:9
+  --> $DIR/rename.rs:82:9
    |
 LL | #![warn(clippy::drop_ref)]
    |         ^^^^^^^^^^^^^^^^ help: use the new name: `dropping_references`
 
 error: lint `clippy::for_loop_over_option` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:82:9
+  --> $DIR/rename.rs:83:9
    |
 LL | #![warn(clippy::for_loop_over_option)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::for_loop_over_result` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:83:9
+  --> $DIR/rename.rs:84:9
    |
 LL | #![warn(clippy::for_loop_over_result)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::for_loops_over_fallibles` has been renamed to `for_loops_over_fallibles`
-  --> $DIR/rename.rs:84:9
+  --> $DIR/rename.rs:85:9
    |
 LL | #![warn(clippy::for_loops_over_fallibles)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `for_loops_over_fallibles`
 
 error: lint `clippy::forget_copy` has been renamed to `forgetting_copy_types`
-  --> $DIR/rename.rs:85:9
+  --> $DIR/rename.rs:86:9
    |
 LL | #![warn(clippy::forget_copy)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `forgetting_copy_types`
 
 error: lint `clippy::forget_ref` has been renamed to `forgetting_references`
-  --> $DIR/rename.rs:86:9
+  --> $DIR/rename.rs:87:9
    |
 LL | #![warn(clippy::forget_ref)]
    |         ^^^^^^^^^^^^^^^^^^ help: use the new name: `forgetting_references`
 
 error: lint `clippy::into_iter_on_array` has been renamed to `array_into_iter`
-  --> $DIR/rename.rs:87:9
+  --> $DIR/rename.rs:88:9
    |
 LL | #![warn(clippy::into_iter_on_array)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `array_into_iter`
 
 error: lint `clippy::invalid_atomic_ordering` has been renamed to `invalid_atomic_ordering`
-  --> $DIR/rename.rs:88:9
+  --> $DIR/rename.rs:89:9
    |
 LL | #![warn(clippy::invalid_atomic_ordering)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_atomic_ordering`
 
 error: lint `clippy::invalid_ref` has been renamed to `invalid_value`
-  --> $DIR/rename.rs:89:9
+  --> $DIR/rename.rs:90:9
    |
 LL | #![warn(clippy::invalid_ref)]
    |         ^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_value`
 
+error: lint `clippy::invalid_utf8_in_unchecked` has been renamed to `invalid_from_utf8_unchecked`
+  --> $DIR/rename.rs:91:9
+   |
+LL | #![warn(clippy::invalid_utf8_in_unchecked)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `invalid_from_utf8_unchecked`
+
 error: lint `clippy::let_underscore_drop` has been renamed to `let_underscore_drop`
-  --> $DIR/rename.rs:90:9
+  --> $DIR/rename.rs:92:9
    |
 LL | #![warn(clippy::let_underscore_drop)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `let_underscore_drop`
 
 error: lint `clippy::mem_discriminant_non_enum` has been renamed to `enum_intrinsics_non_enums`
-  --> $DIR/rename.rs:91:9
+  --> $DIR/rename.rs:93:9
    |
 LL | #![warn(clippy::mem_discriminant_non_enum)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `enum_intrinsics_non_enums`
 
 error: lint `clippy::panic_params` has been renamed to `non_fmt_panics`
-  --> $DIR/rename.rs:92:9
+  --> $DIR/rename.rs:94:9
    |
 LL | #![warn(clippy::panic_params)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panics`
 
 error: lint `clippy::positional_named_format_parameters` has been renamed to `named_arguments_used_positionally`
-  --> $DIR/rename.rs:93:9
+  --> $DIR/rename.rs:95:9
    |
 LL | #![warn(clippy::positional_named_format_parameters)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `named_arguments_used_positionally`
 
 error: lint `clippy::temporary_cstring_as_ptr` has been renamed to `temporary_cstring_as_ptr`
-  --> $DIR/rename.rs:94:9
+  --> $DIR/rename.rs:96:9
    |
 LL | #![warn(clippy::temporary_cstring_as_ptr)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `temporary_cstring_as_ptr`
 
 error: lint `clippy::unknown_clippy_lints` has been renamed to `unknown_lints`
-  --> $DIR/rename.rs:95:9
+  --> $DIR/rename.rs:97:9
    |
 LL | #![warn(clippy::unknown_clippy_lints)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unknown_lints`
 
 error: lint `clippy::unused_label` has been renamed to `unused_labels`
-  --> $DIR/rename.rs:96:9
+  --> $DIR/rename.rs:98:9
    |
 LL | #![warn(clippy::unused_label)]
    |         ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `unused_labels`
 
-error: aborting due to 48 previous errors
+error: aborting due to 49 previous errors
 
diff --git a/tests/ui/lint/invalid_from_utf8.rs b/tests/ui/lint/invalid_from_utf8.rs
new file mode 100644
index 00000000000..9c8c636812e
--- /dev/null
+++ b/tests/ui/lint/invalid_from_utf8.rs
@@ -0,0 +1,93 @@
+// check-pass
+
+#![feature(concat_bytes)]
+#![warn(invalid_from_utf8_unchecked)]
+#![warn(invalid_from_utf8)]
+
+pub fn from_utf8_unchecked_mut() {
+    // Valid
+    unsafe {
+        std::str::from_utf8_unchecked_mut(&mut [99, 108, 105, 112, 112, 121]);
+        std::str::from_utf8_unchecked_mut(&mut [b'c', b'l', b'i', b'p', b'p', b'y']);
+
+        let x = 0xA0;
+        std::str::from_utf8_unchecked_mut(&mut [0xC0, x]);
+    }
+
+    // Invalid
+    unsafe {
+        std::str::from_utf8_unchecked_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `std::str::from_utf8_unchecked_mut`
+        std::str::from_utf8_unchecked_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `std::str::from_utf8_unchecked_mut`
+    }
+}
+
+pub fn from_utf8_unchecked() {
+    // Valid
+    unsafe {
+        std::str::from_utf8_unchecked(&[99, 108, 105, 112, 112, 121]);
+        std::str::from_utf8_unchecked(&[b'c', b'l', b'i', b'p', b'p', b'y']);
+        std::str::from_utf8_unchecked(b"clippy");
+
+        let x = 0xA0;
+        std::str::from_utf8_unchecked(&[0xC0, x]);
+    }
+
+    // Invalid
+    unsafe {
+        std::str::from_utf8_unchecked(&[99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `std::str::from_utf8_unchecked`
+        std::str::from_utf8_unchecked(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `std::str::from_utf8_unchecked`
+        std::str::from_utf8_unchecked(b"cl\x82ippy");
+        //~^ WARN calls to `std::str::from_utf8_unchecked`
+        std::str::from_utf8_unchecked(concat_bytes!(b"cl", b"\x82ippy"));
+        //~^ WARN calls to `std::str::from_utf8_unchecked`
+    }
+}
+
+pub fn from_utf8_mut() {
+    // Valid
+    {
+        std::str::from_utf8_mut(&mut [99, 108, 105, 112, 112, 121]);
+        std::str::from_utf8_mut(&mut [b'c', b'l', b'i', b'p', b'p', b'y']);
+
+        let x = 0xa0;
+        std::str::from_utf8_mut(&mut [0xc0, x]);
+    }
+
+    // Invalid
+    {
+        std::str::from_utf8_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `std::str::from_utf8_mut`
+        std::str::from_utf8_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `std::str::from_utf8_mut`
+    }
+}
+
+pub fn from_utf8() {
+    // Valid
+    {
+        std::str::from_utf8(&[99, 108, 105, 112, 112, 121]);
+        std::str::from_utf8(&[b'c', b'l', b'i', b'p', b'p', b'y']);
+        std::str::from_utf8(b"clippy");
+
+        let x = 0xA0;
+        std::str::from_utf8(&[0xC0, x]);
+    }
+
+    // Invalid
+    {
+        std::str::from_utf8(&[99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `std::str::from_utf8`
+        std::str::from_utf8(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `std::str::from_utf8`
+        std::str::from_utf8(b"cl\x82ippy");
+        //~^ WARN calls to `std::str::from_utf8`
+        std::str::from_utf8(concat_bytes!(b"cl", b"\x82ippy"));
+        //~^ WARN calls to `std::str::from_utf8`
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/lint/invalid_from_utf8.stderr b/tests/ui/lint/invalid_from_utf8.stderr
new file mode 100644
index 00000000000..8e00d3bf872
--- /dev/null
+++ b/tests/ui/lint/invalid_from_utf8.stderr
@@ -0,0 +1,110 @@
+warning: calls to `std::str::from_utf8_unchecked_mut` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:19:9
+   |
+LL |         std::str::from_utf8_unchecked_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^---------------------------------------^
+   |                                           |
+   |                                           the literal was valid UTF-8 up to the 2 bytes
+   |
+note: the lint level is defined here
+  --> $DIR/invalid_from_utf8.rs:4:9
+   |
+LL | #![warn(invalid_from_utf8_unchecked)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8_unchecked_mut` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:21:9
+   |
+LL |         std::str::from_utf8_unchecked_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^--------------------------------------------------^
+   |                                           |
+   |                                           the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8_unchecked` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:39:9
+   |
+LL |         std::str::from_utf8_unchecked(&[99, 108, 130, 105, 112, 112, 121]);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-----------------------------------^
+   |                                       |
+   |                                       the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8_unchecked` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:41:9
+   |
+LL |         std::str::from_utf8_unchecked(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----------------------------------------------^
+   |                                       |
+   |                                       the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8_unchecked` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:43:9
+   |
+LL |         std::str::from_utf8_unchecked(b"cl\x82ippy");
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-------------^
+   |                                       |
+   |                                       the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8_unchecked` with a invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:45:9
+   |
+LL |         std::str::from_utf8_unchecked(concat_bytes!(b"cl", b"\x82ippy"));
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^---------------------------------^
+   |                                       |
+   |                                       the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8_mut` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:62:9
+   |
+LL |         std::str::from_utf8_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^---------------------------------------^
+   |                                 |
+   |                                 the literal was valid UTF-8 up to the 2 bytes
+   |
+note: the lint level is defined here
+  --> $DIR/invalid_from_utf8.rs:5:9
+   |
+LL | #![warn(invalid_from_utf8)]
+   |         ^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8_mut` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:64:9
+   |
+LL |         std::str::from_utf8_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^--------------------------------------------------^
+   |                                 |
+   |                                 the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:82:9
+   |
+LL |         std::str::from_utf8(&[99, 108, 130, 105, 112, 112, 121]);
+   |         ^^^^^^^^^^^^^^^^^^^^-----------------------------------^
+   |                             |
+   |                             the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:84:9
+   |
+LL |         std::str::from_utf8(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+   |         ^^^^^^^^^^^^^^^^^^^^----------------------------------------------^
+   |                             |
+   |                             the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:86:9
+   |
+LL |         std::str::from_utf8(b"cl\x82ippy");
+   |         ^^^^^^^^^^^^^^^^^^^^-------------^
+   |                             |
+   |                             the literal was valid UTF-8 up to the 2 bytes
+
+warning: calls to `std::str::from_utf8` with a invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:88:9
+   |
+LL |         std::str::from_utf8(concat_bytes!(b"cl", b"\x82ippy"));
+   |         ^^^^^^^^^^^^^^^^^^^^---------------------------------^
+   |                             |
+   |                             the literal was valid UTF-8 up to the 2 bytes
+
+warning: 12 warnings emitted
+
diff --git a/tests/ui/process/process-panic-after-fork.rs b/tests/ui/process/process-panic-after-fork.rs
index da268312173..7c2fc296bb0 100644
--- a/tests/ui/process/process-panic-after-fork.rs
+++ b/tests/ui/process/process-panic-after-fork.rs
@@ -11,6 +11,8 @@
 #![feature(never_type)]
 #![feature(panic_always_abort)]
 
+#![allow(invalid_from_utf8)]
+
 extern crate libc;
 
 use std::alloc::{GlobalAlloc, Layout};