Fix lint in a very hacky, fragile way.

rust-lang · Mar 2, 2024 · 178a505 · 178a505
1 parent f683b96
commit 178a505
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Showing 3 changed files with 24 additions and 188 deletions.
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
@@ -1041,8 +1041,23 @@ fn get_nullable_type<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>>
             // must use an Option<fn(..) -> _> to represent it.
             ty
         }
+        ty::Alias(ty::Projection, alias_ty) => {
+            let ty::AliasTy { def_id, args, .. } = alias_ty;
+            debug!("get_nullable_type: alias def_id: {:?}", def_id);
 
-        // We should only ever reach this case if ty_is_known_nonnull is extended
+            let assoc_item = tcx.associated_item(def_id);
+            debug!("get_nullable_type: alias associated_item: {:?}", assoc_item);
+
+            // FIXME: Call `get_nullable_type` with the resolved `alias_ty`.
+            if assoc_item.name.as_str() == "NonZeroInner" {
+                // `<T as ZeroablePrimitive>::NonZeroInner`'s inner value is the same as `T`.
+                return Some(args.type_at(0));
+            }
+
+            debug!("get_nullable_type: unhandled alias: {:?} while checking {:?}", alias_ty, ty);
+            return None;
+        }
+        // We should only ever reach this case if `ty_is_known_nonnull` is extended
         // to other types.
         ref unhandled => {
             debug!(
@@ -1102,13 +1117,7 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
                     return Some(get_nullable_type(tcx, field_ty).unwrap());
                 }
                 WrappingRange { start: 1, .. } => {
-                    let nullable_type = get_nullable_type(tcx, field_ty);
-
-                    if nullable_type.is_none() {
-                        bug!("cannot get nullable type for field_ty {field_ty:?}");
-                    }
-
-                    return Some(nullable_type.unwrap());
+                    return Some(get_nullable_type(tcx, field_ty).unwrap());
                 }
                 WrappingRange { start, end } => {
                     unreachable!("Unhandled start and end range: ({}, {})", start, end)

diff --git a/tests/ui/lint/clashing-extern-fn.stderr b/tests/ui/lint/clashing-extern-fn.stderr
@@ -1,31 +1,3 @@
-warning: `extern` block uses type `Option<NonZero<usize>>`, which is not FFI-safe
-  --> $DIR/clashing-extern-fn.rs:369:43
-   |
-LL |             fn option_non_zero_usize() -> Option<core::num::NonZero<usize>>;
-   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
-   = note: `#[warn(improper_ctypes)]` on by default
-
-warning: `extern` block uses type `Option<NonZero<isize>>`, which is not FFI-safe
-  --> $DIR/clashing-extern-fn.rs:370:43
-   |
-LL |             fn option_non_zero_isize() -> Option<core::num::NonZero<isize>>;
-   |                                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
-
-warning: `extern` block uses type `Option<Transparent>`, which is not FFI-safe
-  --> $DIR/clashing-extern-fn.rs:428:46
-   |
-LL |             fn hidden_niche_transparent() -> Option<Transparent>;
-   |                                              ^^^^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
-
 warning: `extern` block uses type `Option<TransparentNoNiche>`, which is not FFI-safe
   --> $DIR/clashing-extern-fn.rs:430:55
    |
@@ -34,6 +6,7 @@ LL |             fn hidden_niche_transparent_no_niche() -> Option<TransparentNoN
    |
    = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
    = note: enum has no representation hint
+   = note: `#[warn(improper_ctypes)]` on by default
 
 warning: `extern` block uses type `Option<UnsafeCell<NonZero<usize>>>`, which is not FFI-safe
   --> $DIR/clashing-extern-fn.rs:434:46
@@ -205,30 +178,6 @@ LL |             fn non_null_ptr() -> *const usize;
    = note: expected `unsafe extern "C" fn() -> NonNull<usize>`
               found `unsafe extern "C" fn() -> *const usize`
 
-warning: `option_non_zero_usize` redeclared with a different signature
-  --> $DIR/clashing-extern-fn.rs:369:13
-   |
-LL |             fn option_non_zero_usize() -> usize;
-   |             ----------------------------------- `option_non_zero_usize` previously declared here
-...
-LL |             fn option_non_zero_usize() -> Option<core::num::NonZero<usize>>;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this signature doesn't match the previous declaration
-   |
-   = note: expected `unsafe extern "C" fn() -> usize`
-              found `unsafe extern "C" fn() -> Option<NonZero<usize>>`
-
-warning: `option_non_zero_isize` redeclared with a different signature
-  --> $DIR/clashing-extern-fn.rs:370:13
-   |
-LL |             fn option_non_zero_isize() -> isize;
-   |             ----------------------------------- `option_non_zero_isize` previously declared here
-...
-LL |             fn option_non_zero_isize() -> Option<core::num::NonZero<isize>>;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this signature doesn't match the previous declaration
-   |
-   = note: expected `unsafe extern "C" fn() -> isize`
-              found `unsafe extern "C" fn() -> Option<NonZero<isize>>`
-
 warning: `option_non_zero_usize_incorrect` redeclared with a different signature
   --> $DIR/clashing-extern-fn.rs:374:13
    |
@@ -253,18 +202,6 @@ LL |             fn option_non_null_ptr_incorrect() -> *const isize;
    = note: expected `unsafe extern "C" fn() -> *const usize`
               found `unsafe extern "C" fn() -> *const isize`
 
-warning: `hidden_niche_transparent` redeclared with a different signature
-  --> $DIR/clashing-extern-fn.rs:428:13
-   |
-LL |             fn hidden_niche_transparent() -> usize;
-   |             -------------------------------------- `hidden_niche_transparent` previously declared here
-...
-LL |             fn hidden_niche_transparent() -> Option<Transparent>;
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ this signature doesn't match the previous declaration
-   |
-   = note: expected `unsafe extern "C" fn() -> usize`
-              found `unsafe extern "C" fn() -> Option<Transparent>`
-
 warning: `hidden_niche_transparent_no_niche` redeclared with a different signature
   --> $DIR/clashing-extern-fn.rs:430:13
    |
@@ -289,5 +226,5 @@ LL |             fn hidden_niche_unsafe_cell() -> Option<UnsafeCell<NonZero<usiz
    = note: expected `unsafe extern "C" fn() -> usize`
               found `unsafe extern "C" fn() -> Option<UnsafeCell<NonZero<usize>>>`
 
-warning: 25 warnings emitted
+warning: 19 warnings emitted
 
diff --git a/tests/ui/lint/lint-ctypes-enum.stderr b/tests/ui/lint/lint-ctypes-enum.stderr
@@ -45,131 +45,21 @@ note: the type is defined here
 LL | enum T {
    | ^^^^^^
 
-error: `extern` block uses type `Option<NonZero<u8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:71:21
-   |
-LL |    fn nonzero_u8(x: Option<num::NonZero<u8>>);
-   |                     ^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<u16>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:72:22
-   |
-LL |    fn nonzero_u16(x: Option<num::NonZero<u16>>);
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<u32>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:73:22
-   |
-LL |    fn nonzero_u32(x: Option<num::NonZero<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 `Option<NonZero<u64>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:74:22
-   |
-LL |    fn nonzero_u64(x: Option<num::NonZero<u64>>);
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<u128>>`, which is not FFI-safe
+error: `extern` block uses type `u128`, which is not FFI-safe
   --> $DIR/lint-ctypes-enum.rs:75:23
    |
 LL |    fn nonzero_u128(x: Option<num::NonZero<u128>>);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<usize>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:77:24
-   |
-LL |    fn nonzero_usize(x: Option<num::NonZero<usize>>);
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<i8>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:78:21
-   |
-LL |    fn nonzero_i8(x: Option<num::NonZero<i8>>);
-   |                     ^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<i16>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:79:22
-   |
-LL |    fn nonzero_i16(x: Option<num::NonZero<i16>>);
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<i32>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:80:22
-   |
-LL |    fn nonzero_i32(x: Option<num::NonZero<i32>>);
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<i64>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:81:22
-   |
-LL |    fn nonzero_i64(x: Option<num::NonZero<i64>>);
-   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
+   = note: 128-bit integers don't currently have a known stable ABI
 
-error: `extern` block uses type `Option<NonZero<i128>>`, which is not FFI-safe
+error: `extern` block uses type `i128`, which is not FFI-safe
   --> $DIR/lint-ctypes-enum.rs:82:23
    |
 LL |    fn nonzero_i128(x: Option<num::NonZero<i128>>);
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<NonZero<isize>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:84:24
-   |
-LL |    fn nonzero_isize(x: Option<num::NonZero<isize>>);
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<TransparentStruct<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:85:29
-   |
-LL |    fn transparent_struct(x: Option<TransparentStruct<num::NonZero<u8>>>);
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 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 `Option<TransparentEnum<NonZero<u8>>>`, which is not FFI-safe
-  --> $DIR/lint-ctypes-enum.rs:86:27
-   |
-LL |    fn transparent_enum(x: Option<TransparentEnum<num::NonZero<u8>>>);
-   |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe
-   |
-   = help: consider adding a `#[repr(C)]`, `#[repr(transparent)]`, or integer `#[repr(...)]` attribute to this enum
-   = note: enum has no representation hint
+   = note: 128-bit integers don't currently have a known stable ABI
 
 error: `extern` block uses type `Option<TransparentUnion<NonZero<u8>>>`, which is not FFI-safe
   --> $DIR/lint-ctypes-enum.rs:87:28
@@ -198,5 +88,5 @@ LL |    fn no_result(x: Result<(), num::NonZero<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 20 previous errors
+error: aborting due to 8 previous errors