Auto merge of #146271 - niacdoial:improperctypes-refactor1, r=tgross35

lint ImproperCTypes: refactor linting architecture (part 1)

This is the first PR in an effort to split  rust-lang/rust#134697 into individually-mergeable parts.

This one focuses on properly packaging the lint and its tests, as well as properly separate the "linting" and "type-checking" code.

There is exactly one user-visible change: the safety of `Option<Box<FFISafePointee>>` is now the same in `extern` blocks and function definitions: it is safe.

r? `@tgross35` because you are already looking at the original

38 files changed, 106 insertions, 116 deletions

diff --git a/tests/ui/lint/improper_ctypes/allow-phantomdata-in-ffi.rs b/tests/ui/lint/improper-ctypes/allow-phantomdata-in-ffi.rs
index a90159d2b58..a90159d2b58 100644
--- a/tests/ui/lint/improper_ctypes/allow-phantomdata-in-ffi.rs
+++ b/tests/ui/lint/improper-ctypes/allow-phantomdata-in-ffi.rs
diff --git a/tests/ui/lint/lint-ctypes-113436-1.rs b/tests/ui/lint/improper-ctypes/lint-113436-1.rs
index 1ca59c6868d..1ca59c6868d 100644
--- a/tests/ui/lint/lint-ctypes-113436-1.rs
+++ b/tests/ui/lint/improper-ctypes/lint-113436-1.rs
diff --git a/tests/ui/lint/lint-ctypes-113436-1.stderr b/tests/ui/lint/improper-ctypes/lint-113436-1.stderr
index 7b63043f057..f01dc3b6e0d 100644
--- a/tests/ui/lint/lint-ctypes-113436-1.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-113436-1.stderr
@@ -1,5 +1,5 @@
 error: `extern` fn uses type `NotSafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-113436-1.rs:22:22
+  --> $DIR/lint-113436-1.rs:22:22
    |
 LL | extern "C" fn bar(x: Bar) -> Bar {
    |                      ^^^ not FFI-safe
@@ -7,18 +7,18 @@ LL | extern "C" fn bar(x: Bar) -> Bar {
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-113436-1.rs:13:1
+  --> $DIR/lint-113436-1.rs:13:1
    |
 LL | struct NotSafe(u32);
    | ^^^^^^^^^^^^^^
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-113436-1.rs:1:9
+  --> $DIR/lint-113436-1.rs:1:9
    |
 LL | #![deny(improper_ctypes_definitions)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `NotSafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-113436-1.rs:22:30
+  --> $DIR/lint-113436-1.rs:22:30
    |
 LL | extern "C" fn bar(x: Bar) -> Bar {
    |                              ^^^ not FFI-safe
@@ -26,7 +26,7 @@ LL | extern "C" fn bar(x: Bar) -> Bar {
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-113436-1.rs:13:1
+  --> $DIR/lint-113436-1.rs:13:1
    |
 LL | struct NotSafe(u32);
    | ^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-73249-2.rs b/tests/ui/lint/improper-ctypes/lint-73249-2.rs
index 31af0e3d381..31af0e3d381 100644
--- a/tests/ui/lint/lint-ctypes-73249-2.rs
+++ b/tests/ui/lint/improper-ctypes/lint-73249-2.rs
diff --git a/tests/ui/lint/lint-ctypes-73249-2.stderr b/tests/ui/lint/improper-ctypes/lint-73249-2.stderr
index 2d0dfe94f09..d6c1cec2bd6 100644
--- a/tests/ui/lint/lint-ctypes-73249-2.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-73249-2.stderr
@@ -1,12 +1,12 @@
 error: `extern` block uses type `Qux`, which is not FFI-safe
-  --> $DIR/lint-ctypes-73249-2.rs:27:21
+  --> $DIR/lint-73249-2.rs:27:21
    |
 LL |     fn lint_me() -> A<()>;
    |                     ^^^^^ not FFI-safe
    |
    = note: opaque types have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-73249-2.rs:2:9
+  --> $DIR/lint-73249-2.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-73249-3.rs b/tests/ui/lint/improper-ctypes/lint-73249-3.rs
index 8bdf536bf77..8bdf536bf77 100644
--- a/tests/ui/lint/lint-ctypes-73249-3.rs
+++ b/tests/ui/lint/improper-ctypes/lint-73249-3.rs
diff --git a/tests/ui/lint/lint-ctypes-73249-5.stderr b/tests/ui/lint/improper-ctypes/lint-73249-3.stderr
index c4fa955de05..ebc9eb5eb82 100644
--- a/tests/ui/lint/lint-ctypes-73249-5.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-73249-3.stderr
@@ -1,12 +1,12 @@
 error: `extern` block uses type `Qux`, which is not FFI-safe
-  --> $DIR/lint-ctypes-73249-5.rs:21:25
+  --> $DIR/lint-73249-3.rs:21:25
    |
 LL |     pub fn lint_me() -> A;
    |                         ^ not FFI-safe
    |
    = note: opaque types have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-73249-5.rs:2:9
+  --> $DIR/lint-73249-3.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-73249-5.rs b/tests/ui/lint/improper-ctypes/lint-73249-5.rs
index cc6da59950d..cc6da59950d 100644
--- a/tests/ui/lint/lint-ctypes-73249-5.rs
+++ b/tests/ui/lint/improper-ctypes/lint-73249-5.rs
diff --git a/tests/ui/lint/lint-ctypes-73249-3.stderr b/tests/ui/lint/improper-ctypes/lint-73249-5.stderr
index e1a313a2906..484927f57fe 100644
--- a/tests/ui/lint/lint-ctypes-73249-3.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-73249-5.stderr
@@ -1,12 +1,12 @@
 error: `extern` block uses type `Qux`, which is not FFI-safe
-  --> $DIR/lint-ctypes-73249-3.rs:21:25
+  --> $DIR/lint-73249-5.rs:21:25
    |
 LL |     pub fn lint_me() -> A;
    |                         ^ not FFI-safe
    |
    = note: opaque types have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-73249-3.rs:2:9
+  --> $DIR/lint-73249-5.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-73251-1.rs b/tests/ui/lint/improper-ctypes/lint-73251-1.rs
index 07ae05be69f..07ae05be69f 100644
--- a/tests/ui/lint/lint-ctypes-73251-1.rs
+++ b/tests/ui/lint/improper-ctypes/lint-73251-1.rs
diff --git a/tests/ui/lint/lint-ctypes-73251-1.stderr b/tests/ui/lint/improper-ctypes/lint-73251-1.stderr
index 675a9de51cd..749722f0e22 100644
--- a/tests/ui/lint/lint-ctypes-73251-1.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-73251-1.stderr
@@ -1,12 +1,12 @@
 error: `extern` block uses type `Qux`, which is not FFI-safe
-  --> $DIR/lint-ctypes-73251-1.rs:24:21
+  --> $DIR/lint-73251-1.rs:24:21
    |
 LL |     fn lint_me() -> <u32 as Foo>::Assoc;
    |                     ^^^^^^^^^^^^^^^^^^^ not FFI-safe
    |
    = note: opaque types have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-73251-1.rs:2:9
+  --> $DIR/lint-73251-1.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-73251-2.rs b/tests/ui/lint/improper-ctypes/lint-73251-2.rs
index c47118672e0..c47118672e0 100644
--- a/tests/ui/lint/lint-ctypes-73251-2.rs
+++ b/tests/ui/lint/improper-ctypes/lint-73251-2.rs
diff --git a/tests/ui/lint/lint-ctypes-73251-2.stderr b/tests/ui/lint/improper-ctypes/lint-73251-2.stderr
index 634950b29ed..3770b7d789f 100644
--- a/tests/ui/lint/lint-ctypes-73251-2.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-73251-2.stderr
@@ -1,12 +1,12 @@
 error: `extern` block uses type `AliasA`, which is not FFI-safe
-  --> $DIR/lint-ctypes-73251-2.rs:38:21
+  --> $DIR/lint-73251-2.rs:38:21
    |
 LL |     fn lint_me() -> <AliasB as TraitB>::Assoc;
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
    |
    = note: opaque types have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-73251-2.rs:2:9
+  --> $DIR/lint-73251-2.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-94223.rs b/tests/ui/lint/improper-ctypes/lint-94223.rs
index ac24f61b0ac..ac24f61b0ac 100644
--- a/tests/ui/lint/lint-ctypes-94223.rs
+++ b/tests/ui/lint/improper-ctypes/lint-94223.rs
diff --git a/tests/ui/lint/lint-ctypes-94223.stderr b/tests/ui/lint/improper-ctypes/lint-94223.stderr
index bd127cf6004..008debf8f01 100644
--- a/tests/ui/lint/lint-ctypes-94223.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-94223.stderr
@@ -1,5 +1,5 @@
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:4:15
+  --> $DIR/lint-94223.rs:4:15
    |
 LL | pub fn bad(f: extern "C" fn([u8])) {}
    |               ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -7,13 +7,13 @@ LL | pub fn bad(f: extern "C" fn([u8])) {}
    = help: consider using a raw pointer instead
    = note: slices have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-94223.rs:2:9
+  --> $DIR/lint-94223.rs:2:9
    |
 LL | #![deny(improper_ctypes_definitions)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:7:28
+  --> $DIR/lint-94223.rs:7:28
    |
 LL | pub fn bad_twice(f: Result<extern "C" fn([u8]), extern "C" fn([u8])>) {}
    |                            ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -22,7 +22,7 @@ LL | pub fn bad_twice(f: Result<extern "C" fn([u8]), extern "C" fn([u8])>) {}
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:7:49
+  --> $DIR/lint-94223.rs:7:49
    |
 LL | pub fn bad_twice(f: Result<extern "C" fn([u8]), extern "C" fn([u8])>) {}
    |                                                 ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -31,7 +31,7 @@ LL | pub fn bad_twice(f: Result<extern "C" fn([u8]), extern "C" fn([u8])>) {}
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:11:18
+  --> $DIR/lint-94223.rs:11:18
    |
 LL | struct BadStruct(extern "C" fn([u8]));
    |                  ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -40,7 +40,7 @@ LL | struct BadStruct(extern "C" fn([u8]));
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:15:7
+  --> $DIR/lint-94223.rs:15:7
    |
 LL |     A(extern "C" fn([u8])),
    |       ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -49,7 +49,7 @@ LL |     A(extern "C" fn([u8])),
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:20:7
+  --> $DIR/lint-94223.rs:20:7
    |
 LL |     A(extern "C" fn([u8])),
    |       ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -58,7 +58,7 @@ LL |     A(extern "C" fn([u8])),
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `[u8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:24:12
+  --> $DIR/lint-94223.rs:24:12
    |
 LL | type Foo = extern "C" fn([u8]);
    |            ^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -67,7 +67,7 @@ LL | type Foo = extern "C" fn([u8]);
    = note: slices have no C equivalent
 
 error: `extern` fn uses type `Option<&<T as FooTrait>::FooType>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:31:20
+  --> $DIR/lint-94223.rs:31:20
    |
 LL | pub type Foo2<T> = extern "C" fn(Option<&<T as FooTrait>::FooType>);
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -76,7 +76,7 @@ LL | pub type Foo2<T> = extern "C" fn(Option<&<T as FooTrait>::FooType>);
    = note: enum has no representation hint
 
 error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:41:17
+  --> $DIR/lint-94223.rs:41:17
    |
 LL | pub static BAD: extern "C" fn(FfiUnsafe) = f;
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -84,13 +84,13 @@ LL | pub static BAD: extern "C" fn(FfiUnsafe) = f;
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-94223.rs:34:1
+  --> $DIR/lint-94223.rs:34:1
    |
 LL | pub struct FfiUnsafe;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:44:30
+  --> $DIR/lint-94223.rs:44:30
    |
 LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUnsafe)> = Ok(f);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -98,13 +98,13 @@ LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUns
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-94223.rs:34:1
+  --> $DIR/lint-94223.rs:34:1
    |
 LL | pub struct FfiUnsafe;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:44:56
+  --> $DIR/lint-94223.rs:44:56
    |
 LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUnsafe)> = Ok(f);
    |                                                        ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -112,13 +112,13 @@ LL | pub static BAD_TWICE: Result<extern "C" fn(FfiUnsafe), extern "C" fn(FfiUns
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-94223.rs:34:1
+  --> $DIR/lint-94223.rs:34:1
    |
 LL | pub struct FfiUnsafe;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `FfiUnsafe`, which is not FFI-safe
-  --> $DIR/lint-ctypes-94223.rs:48:22
+  --> $DIR/lint-94223.rs:48:22
    |
 LL | pub const BAD_CONST: extern "C" fn(FfiUnsafe) = f;
    |                      ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -126,7 +126,7 @@ LL | pub const BAD_CONST: extern "C" fn(FfiUnsafe) = f;
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/lint-ctypes-94223.rs:34:1
+  --> $DIR/lint-94223.rs:34:1
    |
 LL | pub struct FfiUnsafe;
    | ^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-cstr.rs b/tests/ui/lint/improper-ctypes/lint-cstr.rs
index b04decd0bca..b04decd0bca 100644
--- a/tests/ui/lint/lint-ctypes-cstr.rs
+++ b/tests/ui/lint/improper-ctypes/lint-cstr.rs
diff --git a/tests/ui/lint/lint-ctypes-cstr.stderr b/tests/ui/lint/improper-ctypes/lint-cstr.stderr
index 8957758d577..da263065843 100644
--- a/tests/ui/lint/lint-ctypes-cstr.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-cstr.stderr
@@ -1,5 +1,5 @@
 error: `extern` block uses type `CStr`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:7:21
+  --> $DIR/lint-cstr.rs:7:21
    |
 LL |     fn take_cstr(s: CStr);
    |                     ^^^^ not FFI-safe
@@ -7,13 +7,13 @@ LL |     fn take_cstr(s: CStr);
    = help: consider passing a `*const std::ffi::c_char` instead, and use `CStr::as_ptr()`
    = note: `CStr`/`CString` do not have a guaranteed layout
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-cstr.rs:2:9
+  --> $DIR/lint-cstr.rs:2:9
    |
 LL | #![deny(improper_ctypes, improper_ctypes_definitions)]
    |         ^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `CStr`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:10:25
+  --> $DIR/lint-cstr.rs:10:25
    |
 LL |     fn take_cstr_ref(s: &CStr);
    |                         ^^^^^ not FFI-safe
@@ -22,7 +22,7 @@ LL |     fn take_cstr_ref(s: &CStr);
    = note: `CStr`/`CString` do not have a guaranteed layout
 
 error: `extern` block uses type `CString`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:13:24
+  --> $DIR/lint-cstr.rs:13:24
    |
 LL |     fn take_cstring(s: CString);
    |                        ^^^^^^^ not FFI-safe
@@ -31,7 +31,7 @@ LL |     fn take_cstring(s: CString);
    = note: `CStr`/`CString` do not have a guaranteed layout
 
 error: `extern` block uses type `CString`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:16:28
+  --> $DIR/lint-cstr.rs:16:28
    |
 LL |     fn take_cstring_ref(s: &CString);
    |                            ^^^^^^^^ not FFI-safe
@@ -40,7 +40,7 @@ LL |     fn take_cstring_ref(s: &CString);
    = note: `CStr`/`CString` do not have a guaranteed layout
 
 error: `extern` block uses type `CString`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:20:43
+  --> $DIR/lint-cstr.rs:20:43
    |
 LL |     fn no_special_help_for_mut_cstring(s: *mut CString);
    |                                           ^^^^^^^^^^^^ not FFI-safe
@@ -49,7 +49,7 @@ LL |     fn no_special_help_for_mut_cstring(s: *mut CString);
    = note: this struct has unspecified layout
 
 error: `extern` block uses type `CString`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:24:47
+  --> $DIR/lint-cstr.rs:24:47
    |
 LL |     fn no_special_help_for_mut_cstring_ref(s: &mut CString);
    |                                               ^^^^^^^^^^^^ not FFI-safe
@@ -58,7 +58,7 @@ LL |     fn no_special_help_for_mut_cstring_ref(s: &mut CString);
    = note: this struct has unspecified layout
 
 error: `extern` fn uses type `CStr`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:29:37
+  --> $DIR/lint-cstr.rs:29:37
    |
 LL | extern "C" fn rust_take_cstr_ref(s: &CStr) {}
    |                                     ^^^^^ not FFI-safe
@@ -66,13 +66,13 @@ LL | extern "C" fn rust_take_cstr_ref(s: &CStr) {}
    = help: consider passing a `*const std::ffi::c_char` instead, and use `CStr::as_ptr()`
    = note: `CStr`/`CString` do not have a guaranteed layout
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-cstr.rs:2:26
+  --> $DIR/lint-cstr.rs:2:26
    |
 LL | #![deny(improper_ctypes, improper_ctypes_definitions)]
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `CString`, which is not FFI-safe
-  --> $DIR/lint-ctypes-cstr.rs:32:36
+  --> $DIR/lint-cstr.rs:32:36
    |
 LL | extern "C" fn rust_take_cstring(s: CString) {}
    |                                    ^^^^^^^ not FFI-safe
diff --git a/tests/ui/lint/lint-ctypes.rs b/tests/ui/lint/improper-ctypes/lint-ctypes.rs
index 47586c826ab..7dc06079fa3 100644
--- a/tests/ui/lint/lint-ctypes.rs
+++ b/tests/ui/lint/improper-ctypes/lint-ctypes.rs
@@ -52,7 +52,6 @@ extern "C" {
     pub fn str_type(p: &str); //~ ERROR: uses type `str`
     pub fn box_type(p: Box<u32>); //~ ERROR uses type `Box<u32>`
     pub fn opt_box_type(p: Option<Box<u32>>);
-    //~^ ERROR uses type `Option<Box<u32>>`
     pub fn char_type(p: char); //~ ERROR uses type `char`
     pub fn trait_type(p: &dyn Bar); //~ ERROR uses type `dyn Bar`
     pub fn tuple_type(p: (i32, i32)); //~ ERROR uses type `(i32, i32)`
diff --git a/tests/ui/lint/lint-ctypes.stderr b/tests/ui/lint/improper-ctypes/lint-ctypes.stderr
index 3fb36647d4f..6f8b951c53d 100644
--- a/tests/ui/lint/lint-ctypes.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-ctypes.stderr
@@ -67,17 +67,8 @@ LL |     pub fn box_type(p: Box<u32>);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 
-error: `extern` block uses type `Option<Box<u32>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:54:28
-   |
-LL |     pub fn opt_box_type(p: Option<Box<u32>>);
-   |                            ^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
-
 error: `extern` block uses type `char`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:56:25
+  --> $DIR/lint-ctypes.rs:55:25
    |
 LL |     pub fn char_type(p: char);
    |                         ^^^^ not FFI-safe
@@ -86,7 +77,7 @@ LL |     pub fn char_type(p: char);
    = note: the `char` type has no C equivalent
 
 error: `extern` block uses type `dyn Bar`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:57:26
+  --> $DIR/lint-ctypes.rs:56:26
    |
 LL |     pub fn trait_type(p: &dyn Bar);
    |                          ^^^^^^^^ not FFI-safe
@@ -94,7 +85,7 @@ LL |     pub fn trait_type(p: &dyn Bar);
    = note: trait objects have no C equivalent
 
 error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:58:26
+  --> $DIR/lint-ctypes.rs:57:26
    |
 LL |     pub fn tuple_type(p: (i32, i32));
    |                          ^^^^^^^^^^ not FFI-safe
@@ -103,7 +94,7 @@ LL |     pub fn tuple_type(p: (i32, i32));
    = note: tuples have unspecified layout
 
 error: `extern` block uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:59:27
+  --> $DIR/lint-ctypes.rs:58:27
    |
 LL |     pub fn tuple_type2(p: I32Pair);
    |                           ^^^^^^^ not FFI-safe
@@ -112,7 +103,7 @@ LL |     pub fn tuple_type2(p: I32Pair);
    = note: tuples have unspecified layout
 
 error: `extern` block uses type `ZeroSize`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:60:25
+  --> $DIR/lint-ctypes.rs:59:25
    |
 LL |     pub fn zero_size(p: ZeroSize);
    |                         ^^^^^^^^ not FFI-safe
@@ -126,7 +117,7 @@ LL | pub struct ZeroSize;
    | ^^^^^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:61:33
+  --> $DIR/lint-ctypes.rs:60:33
    |
 LL |     pub fn zero_size_phantom(p: ZeroSizeWithPhantomData);
    |                                 ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -139,7 +130,7 @@ LL | pub struct ZeroSizeWithPhantomData(::std::marker::PhantomData<i32>);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:64:12
+  --> $DIR/lint-ctypes.rs:63:12
    |
 LL |         -> ::std::marker::PhantomData<bool>;
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -147,7 +138,7 @@ LL |         -> ::std::marker::PhantomData<bool>;
    = note: composed only of `PhantomData`
 
 error: `extern` block uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:65:23
+  --> $DIR/lint-ctypes.rs:64:23
    |
 LL |     pub fn fn_type(p: RustFn);
    |                       ^^^^^^ not FFI-safe
@@ -156,7 +147,7 @@ LL |     pub fn fn_type(p: RustFn);
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` block uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:66:24
+  --> $DIR/lint-ctypes.rs:65:24
    |
 LL |     pub fn fn_type2(p: fn());
    |                        ^^^^ not FFI-safe
@@ -165,7 +156,7 @@ LL |     pub fn fn_type2(p: fn());
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` block uses type `Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:67:28
+  --> $DIR/lint-ctypes.rs:66:28
    |
 LL |     pub fn fn_contained(p: RustBadRet);
    |                            ^^^^^^^^^^ not FFI-safe
@@ -174,7 +165,7 @@ LL |     pub fn fn_contained(p: RustBadRet);
    = note: this struct has unspecified layout
 
 error: `extern` block uses type `str`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:68:31
+  --> $DIR/lint-ctypes.rs:67:31
    |
 LL |     pub fn transparent_str(p: TransparentStr);
    |                               ^^^^^^^^^^^^^^ not FFI-safe
@@ -183,7 +174,7 @@ LL |     pub fn transparent_str(p: TransparentStr);
    = note: string slices have no C equivalent
 
 error: `extern` block uses type `Box<u32>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:69:30
+  --> $DIR/lint-ctypes.rs:68:30
    |
 LL |     pub fn transparent_fn(p: TransparentBadFn);
    |                              ^^^^^^^^^^^^^^^^ not FFI-safe
@@ -192,7 +183,7 @@ LL |     pub fn transparent_fn(p: TransparentBadFn);
    = note: this struct has unspecified layout
 
 error: `extern` block uses type `[u8; 8]`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:70:27
+  --> $DIR/lint-ctypes.rs:69:27
    |
 LL |     pub fn raw_array(arr: [u8; 8]);
    |                           ^^^^^^^ not FFI-safe
@@ -201,7 +192,7 @@ LL |     pub fn raw_array(arr: [u8; 8]);
    = note: passing raw arrays by value is not FFI-safe
 
 error: `extern` block uses type `Option<UnsafeCell<extern "C" fn()>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:72:26
+  --> $DIR/lint-ctypes.rs:71:26
    |
 LL |     pub fn no_niche_a(a: Option<UnsafeCell<extern "C" fn()>>);
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -210,7 +201,7 @@ LL |     pub fn no_niche_a(a: Option<UnsafeCell<extern "C" fn()>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Option<UnsafeCell<&i32>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes.rs:74:26
+  --> $DIR/lint-ctypes.rs:73:26
    |
 LL |     pub fn no_niche_b(b: Option<UnsafeCell<&i32>>);
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -218,5 +209,5 @@ LL |     pub fn no_niche_b(b: Option<UnsafeCell<&i32>>);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 
-error: aborting due to 22 previous errors
+error: aborting due to 21 previous errors
 
diff --git a/tests/ui/lint/lint-ctypes-enum.rs b/tests/ui/lint/improper-ctypes/lint-enum.rs
index f900f998d06..f900f998d06 100644
--- a/tests/ui/lint/lint-ctypes-enum.rs
+++ b/tests/ui/lint/improper-ctypes/lint-enum.rs
diff --git a/tests/ui/lint/lint-ctypes-enum.stderr b/tests/ui/lint/improper-ctypes/lint-enum.stderr
index 40d22723309..35d1dcb87fd 100644
--- a/tests/ui/lint/lint-ctypes-enum.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-enum.stderr
@@ -1,5 +1,5 @@
 error: `extern` block uses type `U`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:82:14
+  --> $DIR/lint-enum.rs:82:14
    |
 LL |     fn uf(x: U);
    |              ^ not FFI-safe
@@ -7,18 +7,18 @@ LL |     fn uf(x: U);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:9:1
+  --> $DIR/lint-enum.rs:9:1
    |
 LL | enum U {
    | ^^^^^^
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-enum.rs:2:9
+  --> $DIR/lint-enum.rs:2:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `B`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:83:14
+  --> $DIR/lint-enum.rs:83:14
    |
 LL |     fn bf(x: B);
    |              ^ not FFI-safe
@@ -26,13 +26,13 @@ LL |     fn bf(x: B);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:12:1
+  --> $DIR/lint-enum.rs:12:1
    |
 LL | enum B {
    | ^^^^^^
 
 error: `extern` block uses type `T`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:84:14
+  --> $DIR/lint-enum.rs:84:14
    |
 LL |     fn tf(x: T);
    |              ^ not FFI-safe
@@ -40,13 +40,13 @@ LL |     fn tf(x: T);
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the type is defined here
-  --> $DIR/lint-ctypes-enum.rs:16:1
+  --> $DIR/lint-enum.rs:16:1
    |
 LL | enum T {
    | ^^^^^^
 
 error: `extern` block uses type `Option<TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:108:36
+  --> $DIR/lint-enum.rs:108:36
    |
 LL |     fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>>>);
    |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -55,7 +55,7 @@ LL |     fn option_transparent_union(x: Option<TransparentUnion<num::NonZero<u8>
    = note: enum has no representation hint
 
 error: `extern` block uses type `Option<Rust<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:110:28
+  --> $DIR/lint-enum.rs:110:28
    |
 LL |     fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
    |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -64,7 +64,7 @@ LL |     fn option_repr_rust(x: Option<Rust<num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Option<u8>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:111:21
+  --> $DIR/lint-enum.rs:111:21
    |
 LL |     fn option_u8(x: Option<u8>);
    |                     ^^^^^^^^^^ not FFI-safe
@@ -73,7 +73,7 @@ LL |     fn option_u8(x: Option<u8>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<TransparentUnion<NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:131:38
+  --> $DIR/lint-enum.rs:131:38
    |
 LL |     fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u8>>, ()>);
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -82,7 +82,7 @@ LL |     fn result_transparent_union_t(x: Result<TransparentUnion<num::NonZero<u
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Rust<NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:133:30
+  --> $DIR/lint-enum.rs:133:30
    |
 LL |     fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -91,7 +91,7 @@ LL |     fn result_repr_rust_t(x: Result<Rust<num::NonZero<u8>>, ()>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, U>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:137:51
+  --> $DIR/lint-enum.rs:137:51
    |
 LL |     fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>, U>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -100,7 +100,7 @@ LL |     fn result_1zst_exhaustive_single_variant_t(x: Result<num::NonZero<u8>,
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, B>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:139:53
+  --> $DIR/lint-enum.rs:139:53
    |
 LL |     fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>, B>);
    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -109,7 +109,7 @@ LL |     fn result_1zst_exhaustive_multiple_variant_t(x: Result<num::NonZero<u8>
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, NonExhaustive>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:141:51
+  --> $DIR/lint-enum.rs:141:51
    |
 LL |     fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>, NonExhaustive>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -118,7 +118,7 @@ LL |     fn result_1zst_non_exhaustive_no_variant_t(x: Result<num::NonZero<u8>,
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonZero<u8>, Field>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:144:49
+  --> $DIR/lint-enum.rs:144:49
    |
 LL |     fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Field>);
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -127,7 +127,7 @@ LL |     fn result_1zst_exhaustive_single_field_t(x: Result<num::NonZero<u8>, Fi
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Result<(), NonZero<u8>>, ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:146:30
+  --> $DIR/lint-enum.rs:146:30
    |
 LL |     fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -136,7 +136,7 @@ LL |     fn result_cascading_t(x: Result<Result<(), num::NonZero<u8>>, ()>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:167:38
+  --> $DIR/lint-enum.rs:167:38
    |
 LL |     fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZero<u8>>>);
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -145,7 +145,7 @@ LL |     fn result_transparent_union_e(x: Result<(), TransparentUnion<num::NonZe
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Rust<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:169:30
+  --> $DIR/lint-enum.rs:169:30
    |
 LL |     fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -154,7 +154,7 @@ LL |     fn result_repr_rust_e(x: Result<(), Rust<num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<U, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:173:51
+  --> $DIR/lint-enum.rs:173:51
    |
 LL |     fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8>>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -163,7 +163,7 @@ LL |     fn result_1zst_exhaustive_single_variant_e(x: Result<U, num::NonZero<u8
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<B, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:175:53
+  --> $DIR/lint-enum.rs:175:53
    |
 LL |     fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<u8>>);
    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -172,7 +172,7 @@ LL |     fn result_1zst_exhaustive_multiple_variant_e(x: Result<B, num::NonZero<
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<NonExhaustive, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:177:51
+  --> $DIR/lint-enum.rs:177:51
    |
 LL |     fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num::NonZero<u8>>);
    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -181,7 +181,7 @@ LL |     fn result_1zst_non_exhaustive_no_variant_e(x: Result<NonExhaustive, num
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<Field, NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:180:49
+  --> $DIR/lint-enum.rs:180:49
    |
 LL |     fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<u8>>);
    |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -190,7 +190,7 @@ LL |     fn result_1zst_exhaustive_single_field_e(x: Result<Field, num::NonZero<
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), Result<(), NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:182:30
+  --> $DIR/lint-enum.rs:182:30
    |
 LL |     fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
    |                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -199,7 +199,7 @@ LL |     fn result_cascading_e(x: Result<(), Result<(), num::NonZero<u8>>>);
    = note: enum has no representation hint
 
 error: `extern` block uses type `Result<(), ()>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:184:27
+  --> $DIR/lint-enum.rs:184:27
    |
 LL |     fn result_unit_t_e(x: Result<(), ()>);
    |                           ^^^^^^^^^^^^^^ not FFI-safe
diff --git a/tests/ui/lint/lint-ctypes-fn.rs b/tests/ui/lint/improper-ctypes/lint-fn.rs
index 0b84098e390..0b84098e390 100644
--- a/tests/ui/lint/lint-ctypes-fn.rs
+++ b/tests/ui/lint/improper-ctypes/lint-fn.rs
diff --git a/tests/ui/lint/lint-ctypes-fn.stderr b/tests/ui/lint/improper-ctypes/lint-fn.stderr
index a19c04a63b5..34e3bd021b9 100644
--- a/tests/ui/lint/lint-ctypes-fn.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-fn.stderr
@@ -1,5 +1,5 @@
 error: `extern` fn uses type `[u32]`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:70:33
+  --> $DIR/lint-fn.rs:70:33
    |
 LL | pub extern "C" fn slice_type(p: &[u32]) { }
    |                                 ^^^^^^ not FFI-safe
@@ -7,13 +7,13 @@ LL | pub extern "C" fn slice_type(p: &[u32]) { }
    = help: consider using a raw pointer instead
    = note: slices have no C equivalent
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-fn.rs:2:9
+  --> $DIR/lint-fn.rs:2:9
    |
 LL | #![deny(improper_ctypes_definitions)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `str`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:73:31
+  --> $DIR/lint-fn.rs:73:31
    |
 LL | pub extern "C" fn str_type(p: &str) { }
    |                               ^^^^ not FFI-safe
@@ -22,7 +22,7 @@ LL | pub extern "C" fn str_type(p: &str) { }
    = note: string slices have no C equivalent
 
 error: `extern` fn uses type `Box<[u8]>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:80:34
+  --> $DIR/lint-fn.rs:80:34
    |
 LL | pub extern "C" fn boxed_slice(p: Box<[u8]>) { }
    |                                  ^^^^^^^^^ not FFI-safe
@@ -30,7 +30,7 @@ LL | pub extern "C" fn boxed_slice(p: Box<[u8]>) { }
    = note: box cannot be represented as a single pointer
 
 error: `extern` fn uses type `Box<str>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:83:35
+  --> $DIR/lint-fn.rs:83:35
    |
 LL | pub extern "C" fn boxed_string(p: Box<str>) { }
    |                                   ^^^^^^^^ not FFI-safe
@@ -38,7 +38,7 @@ LL | pub extern "C" fn boxed_string(p: Box<str>) { }
    = note: box cannot be represented as a single pointer
 
 error: `extern` fn uses type `Box<dyn Trait>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:86:34
+  --> $DIR/lint-fn.rs:86:34
    |
 LL | pub extern "C" fn boxed_trait(p: Box<dyn Trait>) { }
    |                                  ^^^^^^^^^^^^^^ not FFI-safe
@@ -46,7 +46,7 @@ LL | pub extern "C" fn boxed_trait(p: Box<dyn Trait>) { }
    = note: box cannot be represented as a single pointer
 
 error: `extern` fn uses type `char`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:89:32
+  --> $DIR/lint-fn.rs:89:32
    |
 LL | pub extern "C" fn char_type(p: char) { }
    |                                ^^^^ not FFI-safe
@@ -55,7 +55,7 @@ LL | pub extern "C" fn char_type(p: char) { }
    = note: the `char` type has no C equivalent
 
 error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:92:33
+  --> $DIR/lint-fn.rs:92:33
    |
 LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
    |                                 ^^^^^^^^^^ not FFI-safe
@@ -64,7 +64,7 @@ LL | pub extern "C" fn tuple_type(p: (i32, i32)) { }
    = note: tuples have unspecified layout
 
 error: `extern` fn uses type `(i32, i32)`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:95:34
+  --> $DIR/lint-fn.rs:95:34
    |
 LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
    |                                  ^^^^^^^ not FFI-safe
@@ -73,7 +73,7 @@ LL | pub extern "C" fn tuple_type2(p: I32Pair) { }
    = note: tuples have unspecified layout
 
 error: `extern` fn uses type `ZeroSize`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:98:32
+  --> $DIR/lint-fn.rs:98:32
    |
 LL | pub extern "C" fn zero_size(p: ZeroSize) { }
    |                                ^^^^^^^^ not FFI-safe
@@ -81,26 +81,26 @@ LL | pub extern "C" fn zero_size(p: ZeroSize) { }
    = help: consider adding a member to this struct
    = note: this struct has no fields
 note: the type is defined here
-  --> $DIR/lint-ctypes-fn.rs:25:1
+  --> $DIR/lint-fn.rs:25:1
    |
 LL | pub struct ZeroSize;
    | ^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `ZeroSizeWithPhantomData`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:101:40
+  --> $DIR/lint-fn.rs:101:40
    |
 LL | pub extern "C" fn zero_size_phantom(p: ZeroSizeWithPhantomData) { }
    |                                        ^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
    |
    = note: composed only of `PhantomData`
 note: the type is defined here
-  --> $DIR/lint-ctypes-fn.rs:60:1
+  --> $DIR/lint-fn.rs:60:1
    |
 LL | pub struct ZeroSizeWithPhantomData(PhantomData<i32>);
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: `extern` fn uses type `PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:104:51
+  --> $DIR/lint-fn.rs:104:51
    |
 LL | pub extern "C" fn zero_size_phantom_toplevel() -> PhantomData<bool> {
    |                                                   ^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -108,7 +108,7 @@ LL | pub extern "C" fn zero_size_phantom_toplevel() -> PhantomData<bool> {
    = note: composed only of `PhantomData`
 
 error: `extern` fn uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:109:30
+  --> $DIR/lint-fn.rs:109:30
    |
 LL | pub extern "C" fn fn_type(p: RustFn) { }
    |                              ^^^^^^ not FFI-safe
@@ -117,7 +117,7 @@ LL | pub extern "C" fn fn_type(p: RustFn) { }
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` fn uses type `fn()`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:112:31
+  --> $DIR/lint-fn.rs:112:31
    |
 LL | pub extern "C" fn fn_type2(p: fn()) { }
    |                               ^^^^ not FFI-safe
@@ -126,7 +126,7 @@ LL | pub extern "C" fn fn_type2(p: fn()) { }
    = note: this function pointer has Rust-specific calling convention
 
 error: `extern` fn uses type `str`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:117:38
+  --> $DIR/lint-fn.rs:117:38
    |
 LL | pub extern "C" fn transparent_str(p: TransparentStr) { }
    |                                      ^^^^^^^^^^^^^^ not FFI-safe
@@ -135,7 +135,7 @@ LL | pub extern "C" fn transparent_str(p: TransparentStr) { }
    = note: string slices have no C equivalent
 
 error: `extern` fn uses type `PhantomData<bool>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:169:43
+  --> $DIR/lint-fn.rs:169:43
    |
 LL | pub extern "C" fn unused_generic2<T>() -> PhantomData<bool> {
    |                                           ^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -143,7 +143,7 @@ LL | pub extern "C" fn unused_generic2<T>() -> PhantomData<bool> {
    = note: composed only of `PhantomData`
 
 error: `extern` fn uses type `Vec<T>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:182:39
+  --> $DIR/lint-fn.rs:182:39
    |
 LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
    |                                       ^^^^^^ not FFI-safe
@@ -152,7 +152,7 @@ LL | pub extern "C" fn used_generic4<T>(x: Vec<T>) { }
    = note: this struct has unspecified layout
 
 error: `extern` fn uses type `Vec<T>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-fn.rs:185:41
+  --> $DIR/lint-fn.rs:185:41
    |
 LL | pub extern "C" fn used_generic5<T>() -> Vec<T> {
    |                                         ^^^^^^ not FFI-safe
diff --git a/tests/ui/lint/lint-ctypes-non-recursion-limit.rs b/tests/ui/lint/improper-ctypes/lint-non-recursion-limit.rs
index 61e95dc5a46..61e95dc5a46 100644
--- a/tests/ui/lint/lint-ctypes-non-recursion-limit.rs
+++ b/tests/ui/lint/improper-ctypes/lint-non-recursion-limit.rs
diff --git a/tests/ui/lint/lint-ctypes-option-nonnull-unsized.rs b/tests/ui/lint/improper-ctypes/lint-option-nonnull-unsized.rs
index ca08eb23a57..ca08eb23a57 100644
--- a/tests/ui/lint/lint-ctypes-option-nonnull-unsized.rs
+++ b/tests/ui/lint/improper-ctypes/lint-option-nonnull-unsized.rs
diff --git a/tests/ui/lint/lint-ctypes-option-nonnull-unsized.stderr b/tests/ui/lint/improper-ctypes/lint-option-nonnull-unsized.stderr
index 74630469416..b17fb6bd614 100644
--- a/tests/ui/lint/lint-ctypes-option-nonnull-unsized.stderr
+++ b/tests/ui/lint/improper-ctypes/lint-option-nonnull-unsized.stderr
@@ -1,5 +1,5 @@
 error: `extern` fn uses type `Option<&T>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-option-nonnull-unsized.rs:3:45
+  --> $DIR/lint-option-nonnull-unsized.rs:3:45
    |
 LL | extern "C" fn foo<T: ?Sized + 'static>() -> Option<&'static T> {
    |                                             ^^^^^^^^^^^^^^^^^^ not FFI-safe
@@ -7,7 +7,7 @@ LL | extern "C" fn foo<T: ?Sized + 'static>() -> Option<&'static T> {
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
 note: the lint level is defined here
-  --> $DIR/lint-ctypes-option-nonnull-unsized.rs:1:9
+  --> $DIR/lint-option-nonnull-unsized.rs:1:9
    |
 LL | #![deny(improper_ctypes_definitions)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/tests/ui/lint/lint-ctypes-113436.rs b/tests/ui/lint/improper-ctypes/mustpass-113436.rs
index d5acdc45f92..d5acdc45f92 100644
--- a/tests/ui/lint/lint-ctypes-113436.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-113436.rs
diff --git a/tests/ui/lint/lint-ctypes-113900.rs b/tests/ui/lint/improper-ctypes/mustpass-113900.rs
index 3dd196a4094..3dd196a4094 100644
--- a/tests/ui/lint/lint-ctypes-113900.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-113900.rs
diff --git a/tests/ui/lint/improper_ctypes_definitions_ice_134060.rs b/tests/ui/lint/improper-ctypes/mustpass-134060.rs
index b30be996736..b30be996736 100644
--- a/tests/ui/lint/improper_ctypes_definitions_ice_134060.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-134060.rs
diff --git a/tests/ui/lint/improper_ctypes_definitions_ice_134060.stderr b/tests/ui/lint/improper-ctypes/mustpass-134060.stderr
index f6ac9a92cd5..791b2f73709 100644
--- a/tests/ui/lint/improper_ctypes_definitions_ice_134060.stderr
+++ b/tests/ui/lint/improper-ctypes/mustpass-134060.stderr
@@ -1,5 +1,5 @@
 warning: `extern` fn uses type `()`, which is not FFI-safe
-  --> $DIR/improper_ctypes_definitions_ice_134060.rs:11:34
+  --> $DIR/mustpass-134060.rs:11:34
    |
 LL |     extern "C" fn foo_(&self, _: ()) -> i64 {
    |                                  ^^ not FFI-safe
diff --git a/tests/ui/lint/lint-ctypes-66202.rs b/tests/ui/lint/improper-ctypes/mustpass-66202.rs
index e4cfa54c8d8..e4cfa54c8d8 100644
--- a/tests/ui/lint/lint-ctypes-66202.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-66202.rs
diff --git a/tests/ui/lint/lint-ctypes-73249-1.rs b/tests/ui/lint/improper-ctypes/mustpass-73249-1.rs
index 0ca91ef294f..0ca91ef294f 100644
--- a/tests/ui/lint/lint-ctypes-73249-1.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-73249-1.rs
diff --git a/tests/ui/lint/lint-ctypes-73249-4.rs b/tests/ui/lint/improper-ctypes/mustpass-73249-4.rs
index 37099c1313a..37099c1313a 100644
--- a/tests/ui/lint/lint-ctypes-73249-4.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-73249-4.rs
diff --git a/tests/ui/lint/lint-ctypes-73249.rs b/tests/ui/lint/improper-ctypes/mustpass-73249.rs
index c5f2318ef0a..c5f2318ef0a 100644
--- a/tests/ui/lint/lint-ctypes-73249.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-73249.rs
diff --git a/tests/ui/lint/lint-ctypes-73251.rs b/tests/ui/lint/improper-ctypes/mustpass-73251.rs
index 15c1dfcaabf..15c1dfcaabf 100644
--- a/tests/ui/lint/lint-ctypes-73251.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-73251.rs
diff --git a/tests/ui/lint/lint-ctypes-73747.rs b/tests/ui/lint/improper-ctypes/mustpass-73747.rs
index a2562e3b421..a2562e3b421 100644
--- a/tests/ui/lint/lint-ctypes-73747.rs
+++ b/tests/ui/lint/improper-ctypes/mustpass-73747.rs
diff --git a/tests/ui/lint/improper_ctypes/repr-rust-is-undefined.rs b/tests/ui/lint/improper-ctypes/repr-rust-is-undefined.rs
index 379c4132404..379c4132404 100644
--- a/tests/ui/lint/improper_ctypes/repr-rust-is-undefined.rs
+++ b/tests/ui/lint/improper-ctypes/repr-rust-is-undefined.rs
diff --git a/tests/ui/lint/improper_ctypes/repr-rust-is-undefined.stderr b/tests/ui/lint/improper-ctypes/repr-rust-is-undefined.stderr
index 5f0465bcf00..5f0465bcf00 100644
--- a/tests/ui/lint/improper_ctypes/repr-rust-is-undefined.stderr
+++ b/tests/ui/lint/improper-ctypes/repr-rust-is-undefined.stderr