invalid_from_utf8[_unchecked]: also lint inherent methods

6 files changed, 269 insertions, 43 deletions

diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl
index 480d97e377a..dbe24c9cdf2 100644
--- a/compiler/rustc_lint/messages.ftl
+++ b/compiler/rustc_lint/messages.ftl
@@ -439,11 +439,11 @@ lint_invalid_crate_type_value = invalid `crate_type` value
     .suggestion = did you mean
 
 # 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
+lint_invalid_from_utf8_checked = calls to `{$method}` with an invalid literal always return an error
     .label = the literal was valid UTF-8 up to the {$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
+lint_invalid_from_utf8_unchecked = calls to `{$method}` with an invalid literal are undefined behavior
     .label = the literal was valid UTF-8 up to the {$valid_up_to} bytes
 
 lint_invalid_nan_comparisons_eq_ne = incorrect NaN comparison, NaN cannot be directly compared to itself
diff --git a/compiler/rustc_lint/src/invalid_from_utf8.rs b/compiler/rustc_lint/src/invalid_from_utf8.rs
index 0081374922e..11eb079ddc0 100644
--- a/compiler/rustc_lint/src/invalid_from_utf8.rs
+++ b/compiler/rustc_lint/src/invalid_from_utf8.rs
@@ -70,12 +70,20 @@ impl<'tcx> LateLintPass<'tcx> for InvalidFromUtf8 {
                 sym::str_from_utf8_mut,
                 sym::str_from_utf8_unchecked,
                 sym::str_from_utf8_unchecked_mut,
+                sym::str_inherent_from_utf8,
+                sym::str_inherent_from_utf8_mut,
+                sym::str_inherent_from_utf8_unchecked,
+                sym::str_inherent_from_utf8_unchecked_mut,
             ]
             .contains(&diag_item)
         {
             let lint = |label, utf8_error: Utf8Error| {
                 let method = diag_item.as_str().strip_prefix("str_").unwrap();
-                let method = format!("std::str::{method}");
+                let method = if let Some(method) = method.strip_prefix("inherent_") {
+                    format!("str::{method}")
+                } else {
+                    format!("std::str::{method}")
+                };
                 let valid_up_to = utf8_error.valid_up_to();
                 let is_unchecked_variant = diag_item.as_str().contains("unchecked");
 
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index 62723e385cf..4c2f7ad6d3c 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -1973,6 +1973,10 @@ symbols! {
         str_from_utf8_mut,
         str_from_utf8_unchecked,
         str_from_utf8_unchecked_mut,
+        str_inherent_from_utf8,
+        str_inherent_from_utf8_mut,
+        str_inherent_from_utf8_unchecked,
+        str_inherent_from_utf8_unchecked_mut,
         str_len,
         str_split_whitespace,
         str_starts_with,
diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index 05c16791ce7..fd2cd59f88e 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -238,6 +238,7 @@ impl str {
     /// assert_eq!("💖", sparkle_heart);
     /// ```
     #[unstable(feature = "inherent_str_constructors", issue = "131114")]
+    #[rustc_diagnostic_item = "str_inherent_from_utf8"]
     pub const fn from_utf8(v: &[u8]) -> Result<&str, Utf8Error> {
         converts::from_utf8(v)
     }
@@ -274,6 +275,7 @@ impl str {
     /// errors that can be returned.
     #[unstable(feature = "inherent_str_constructors", issue = "131114")]
     #[rustc_const_unstable(feature = "const_str_from_utf8", issue = "91006")]
+    #[rustc_diagnostic_item = "str_inherent_from_utf8_mut"]
     pub const fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> {
         converts::from_utf8_mut(v)
     }
@@ -306,6 +308,7 @@ impl str {
     #[inline]
     #[must_use]
     #[unstable(feature = "inherent_str_constructors", issue = "131114")]
+    #[rustc_diagnostic_item = "str_inherent_from_utf8_unchecked"]
     pub const unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
         // SAFETY: converts::from_utf8_unchecked has the same safety requirements as this function.
         unsafe { converts::from_utf8_unchecked(v) }
@@ -331,6 +334,7 @@ impl str {
     #[inline]
     #[must_use]
     #[unstable(feature = "inherent_str_constructors", issue = "131114")]
+    #[rustc_diagnostic_item = "str_inherent_from_utf8_unchecked_mut"]
     pub const unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str {
         // SAFETY: converts::from_utf8_unchecked_mut has the same safety requirements as this function.
         unsafe { converts::from_utf8_unchecked_mut(v) }
diff --git a/tests/ui/lint/invalid_from_utf8.rs b/tests/ui/lint/invalid_from_utf8.rs
index 2d1822a54ac..8f8000fe34d 100644
--- a/tests/ui/lint/invalid_from_utf8.rs
+++ b/tests/ui/lint/invalid_from_utf8.rs
@@ -1,7 +1,7 @@
 //@ check-pass
 
 #![feature(concat_bytes)]
-
+#![feature(inherent_str_constructors)]
 #![warn(invalid_from_utf8_unchecked)]
 #![warn(invalid_from_utf8)]
 
@@ -9,7 +9,9 @@ pub fn from_utf8_unchecked_mut() {
     // Valid
     unsafe {
         std::str::from_utf8_unchecked_mut(&mut [99, 108, 105, 112, 112, 121]);
+        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']);
+        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]);
@@ -19,8 +21,12 @@ pub fn from_utf8_unchecked_mut() {
     unsafe {
         std::str::from_utf8_unchecked_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
         //~^ WARN calls to `std::str::from_utf8_unchecked_mut`
+        str::from_utf8_unchecked_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `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`
+        str::from_utf8_unchecked_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `str::from_utf8_unchecked_mut`
     }
 }
 
@@ -28,23 +34,35 @@ pub fn from_utf8_unchecked() {
     // Valid
     unsafe {
         std::str::from_utf8_unchecked(&[99, 108, 105, 112, 112, 121]);
+        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']);
+        str::from_utf8_unchecked(&[b'c', b'l', b'i', b'p', b'p', b'y']);
         std::str::from_utf8_unchecked(b"clippy");
+        str::from_utf8_unchecked(b"clippy");
 
         let x = 0xA0;
         std::str::from_utf8_unchecked(&[0xC0, x]);
+        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`
+        str::from_utf8_unchecked(&[99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `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`
+        str::from_utf8_unchecked(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `str::from_utf8_unchecked`
         std::str::from_utf8_unchecked(b"cl\x82ippy");
         //~^ WARN calls to `std::str::from_utf8_unchecked`
+        str::from_utf8_unchecked(b"cl\x82ippy");
+        //~^ WARN calls to `str::from_utf8_unchecked`
         std::str::from_utf8_unchecked(concat_bytes!(b"cl", b"\x82ippy"));
         //~^ WARN calls to `std::str::from_utf8_unchecked`
+        str::from_utf8_unchecked(concat_bytes!(b"cl", b"\x82ippy"));
+        //~^ WARN calls to `str::from_utf8_unchecked`
     }
 }
 
@@ -52,18 +70,25 @@ pub fn from_utf8_mut() {
     // Valid
     {
         std::str::from_utf8_mut(&mut [99, 108, 105, 112, 112, 121]);
+        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']);
+        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]);
+        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`
+        str::from_utf8_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `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`
+        str::from_utf8_mut(&mut [b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `str::from_utf8_mut`
     }
 }
 
@@ -71,23 +96,35 @@ pub fn from_utf8() {
     // Valid
     {
         std::str::from_utf8(&[99, 108, 105, 112, 112, 121]);
+        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']);
+        str::from_utf8(&[b'c', b'l', b'i', b'p', b'p', b'y']);
         std::str::from_utf8(b"clippy");
+        str::from_utf8(b"clippy");
 
         let x = 0xA0;
         std::str::from_utf8(&[0xC0, x]);
+        str::from_utf8(&[0xC0, x]);
     }
 
     // Invalid
     {
         std::str::from_utf8(&[99, 108, 130, 105, 112, 112, 121]);
         //~^ WARN calls to `std::str::from_utf8`
+        str::from_utf8(&[99, 108, 130, 105, 112, 112, 121]);
+        //~^ WARN calls to `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`
+        str::from_utf8(&[b'c', b'l', b'\x82', b'i', b'p', b'p', b'y']);
+        //~^ WARN calls to `str::from_utf8`
         std::str::from_utf8(b"cl\x82ippy");
         //~^ WARN calls to `std::str::from_utf8`
+        str::from_utf8(b"cl\x82ippy");
+        //~^ WARN calls to `str::from_utf8`
         std::str::from_utf8(concat_bytes!(b"cl", b"\x82ippy"));
         //~^ WARN calls to `std::str::from_utf8`
+        str::from_utf8(concat_bytes!(b"cl", b"\x82ippy"));
+        //~^ WARN calls to `str::from_utf8`
     }
 }
 
@@ -95,25 +132,39 @@ pub fn from_utf8_with_indirections() {
     let mut a = [99, 108, 130, 105, 112, 112, 121];
     std::str::from_utf8_mut(&mut a);
     //~^ WARN calls to `std::str::from_utf8_mut`
+    str::from_utf8_mut(&mut a);
+    //~^ WARN calls to `str::from_utf8_mut`
     let mut b = &mut a;
     let mut c = b;
     std::str::from_utf8_mut(c);
     //~^ WARN calls to `std::str::from_utf8_mut`
+    str::from_utf8_mut(c);
+    //~^ WARN calls to `str::from_utf8_mut`
     let mut c = &[99, 108, 130, 105, 112, 112, 121];
     std::str::from_utf8(c);
     //~^ WARN calls to `std::str::from_utf8`
+    str::from_utf8(c);
+    //~^ WARN calls to `str::from_utf8`
     const INVALID_1: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
     std::str::from_utf8(&INVALID_1);
     //~^ WARN calls to `std::str::from_utf8`
+    str::from_utf8(&INVALID_1);
+    //~^ WARN calls to `str::from_utf8`
     static INVALID_2: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
     std::str::from_utf8(&INVALID_2);
     //~^ WARN calls to `std::str::from_utf8`
+    str::from_utf8(&INVALID_2);
+    //~^ WARN calls to `str::from_utf8`
     const INVALID_3: &'static [u8; 7] = &[99, 108, 130, 105, 112, 112, 121];
     std::str::from_utf8(INVALID_3);
     //~^ WARN calls to `std::str::from_utf8`
+    str::from_utf8(INVALID_3);
+    //~^ WARN calls to `str::from_utf8`
     const INVALID_4: &'static [u8; 7] = { &[99, 108, 130, 105, 112, 112, 121] };
     std::str::from_utf8(INVALID_4);
     //~^ WARN calls to `std::str::from_utf8`
+    str::from_utf8(INVALID_4);
+    //~^ WARN calls to `str::from_utf8`
 }
 
 fn main() {}
diff --git a/tests/ui/lint/invalid_from_utf8.stderr b/tests/ui/lint/invalid_from_utf8.stderr
index 07616e11801..715ecf56f21 100644
--- a/tests/ui/lint/invalid_from_utf8.stderr
+++ b/tests/ui/lint/invalid_from_utf8.stderr
@@ -1,5 +1,5 @@
-warning: calls to `std::str::from_utf8_unchecked_mut` with a invalid literal are undefined behavior
-  --> $DIR/invalid_from_utf8.rs:20:9
+warning: calls to `std::str::from_utf8_unchecked_mut` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:22:9
    |
 LL |         std::str::from_utf8_unchecked_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----------------------------------^
@@ -12,48 +12,96 @@ note: the lint level is defined here
 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:22:9
+warning: calls to `str::from_utf8_unchecked_mut` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:24:9
+   |
+LL |         str::from_utf8_unchecked_mut(&mut [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_mut` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:26:9
    |
 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:40:9
+warning: calls to `str::from_utf8_unchecked_mut` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:28:9
+   |
+LL |         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 an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:50:9
    |
 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:42:9
+warning: calls to `str::from_utf8_unchecked` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:52:9
+   |
+LL |         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 an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:54:9
    |
 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:44:9
+warning: calls to `str::from_utf8_unchecked` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:56:9
+   |
+LL |         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 an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:58:9
    |
 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:46:9
+warning: calls to `str::from_utf8_unchecked` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:60:9
+   |
+LL |         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 an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:62:9
    |
 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:63:9
+warning: calls to `str::from_utf8_unchecked` with an invalid literal are undefined behavior
+  --> $DIR/invalid_from_utf8.rs:64:9
+   |
+LL |         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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:84:9
    |
 LL |         std::str::from_utf8_mut(&mut [99, 108, 130, 105, 112, 112, 121]);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^----------------------------------^
@@ -66,56 +114,113 @@ note: the lint level is defined here
 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:65:9
+warning: calls to `str::from_utf8_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:86:9
+   |
+LL |         str::from_utf8_mut(&mut [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_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:88:9
    |
 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:83:9
+warning: calls to `str::from_utf8_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:90:9
+   |
+LL |         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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:112:9
    |
 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:85:9
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:114:9
+   |
+LL |         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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:116:9
    |
 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:87:9
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:118:9
+   |
+LL |         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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:120:9
    |
 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:89:9
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:122:9
+   |
+LL |         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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:124:9
    |
 LL |         std::str::from_utf8(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:96:5
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:126:9
+   |
+LL |         str::from_utf8(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 an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:133:5
    |
 LL |     let mut a = [99, 108, 130, 105, 112, 112, 121];
    |                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8_mut(&mut a);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8_mut` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:100:5
+warning: calls to `str::from_utf8_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:135:5
+   |
+LL |     let mut a = [99, 108, 130, 105, 112, 112, 121];
+   |                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8_mut(&mut a);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:139:5
    |
 LL |     let mut a = [99, 108, 130, 105, 112, 112, 121];
    |                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
@@ -123,45 +228,99 @@ LL |     let mut a = [99, 108, 130, 105, 112, 112, 121];
 LL |     std::str::from_utf8_mut(c);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:103:5
+warning: calls to `str::from_utf8_mut` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:141:5
+   |
+LL |     let mut a = [99, 108, 130, 105, 112, 112, 121];
+   |                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8_mut(c);
+   |     ^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:144:5
    |
 LL |     let mut c = &[99, 108, 130, 105, 112, 112, 121];
    |                  ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8(c);
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:106:5
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:146:5
+   |
+LL |     let mut c = &[99, 108, 130, 105, 112, 112, 121];
+   |                  ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8(c);
+   |     ^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:149:5
    |
 LL |     const INVALID_1: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
    |                                ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8(&INVALID_1);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:109:5
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:151:5
+   |
+LL |     const INVALID_1: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
+   |                                ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8(&INVALID_1);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:154:5
    |
 LL |     static INVALID_2: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
    |                                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8(&INVALID_2);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:112:5
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:156:5
+   |
+LL |     static INVALID_2: [u8; 7] = [99, 108, 130, 105, 112, 112, 121];
+   |                                 ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8(&INVALID_2);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:159:5
    |
 LL |     const INVALID_3: &'static [u8; 7] = &[99, 108, 130, 105, 112, 112, 121];
    |                                          ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8(INVALID_3);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: calls to `std::str::from_utf8` with a invalid literal always return an error
-  --> $DIR/invalid_from_utf8.rs:115:5
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:161:5
+   |
+LL |     const INVALID_3: &'static [u8; 7] = &[99, 108, 130, 105, 112, 112, 121];
+   |                                          ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8(INVALID_3);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: calls to `std::str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:164:5
    |
 LL |     const INVALID_4: &'static [u8; 7] = { &[99, 108, 130, 105, 112, 112, 121] };
    |                                            ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
 LL |     std::str::from_utf8(INVALID_4);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: 19 warnings emitted
+warning: calls to `str::from_utf8` with an invalid literal always return an error
+  --> $DIR/invalid_from_utf8.rs:166:5
+   |
+LL |     const INVALID_4: &'static [u8; 7] = { &[99, 108, 130, 105, 112, 112, 121] };
+   |                                            ---------------------------------- the literal was valid UTF-8 up to the 2 bytes
+...
+LL |     str::from_utf8(INVALID_4);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 38 warnings emitted