Rollup merge of #153960 - Zoxc:fatal-layout-of-cycles, r=TaKO8Ki

Make `layout_of` cycles fatal errors

This makes `layout_of` cycles fatal errors.

This is a step towards removing query cycle recovery.

compiler/rustc_codegen_llvm/src/context.rs

@@ -1134,11 +1134,7 @@ fn handle_fn_abi_err(
         fn_abi_request: FnAbiRequest<'tcx>,
     ) -> ! {
         match err {
-            FnAbiError::Layout(
-                LayoutError::SizeOverflow(_)
-                | LayoutError::Cycle(_)
-                | LayoutError::InvalidSimd { .. },
-            ) => {
+            FnAbiError::Layout(LayoutError::SizeOverflow(_) | LayoutError::InvalidSimd { .. }) => {
                 self.tcx.dcx().emit_fatal(Spanned { span, node: err });
             }
             _ => match fn_abi_request {

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -107,8 +107,7 @@ fn handle_layout_err(
             | LayoutError::SizeOverflow(_)
             | LayoutError::InvalidSimd { .. }
             | LayoutError::TooGeneric(_)
-            | LayoutError::ReferencesError(_)
-            | LayoutError::Cycle(_) => {}
+            | LayoutError::ReferencesError(_) => {}
         }
         err_inval!(Layout(err))
     }

compiler/rustc_hir_analysis/src/hir_ty_lowering/cmse.rs

@@ -194,8 +194,7 @@ fn should_emit_layout_error<'tcx>(abi: ExternAbi, layout_err: &'tcx LayoutError<
         | SizeOverflow(..)
         | InvalidSimd { .. }
         | NormalizationFailure(..)
-        | ReferencesError(..)
-        | Cycle(..) => {
+        | ReferencesError(..) => {
             false // not our job to report these
         }
     }

compiler/rustc_middle/src/ty/layout.rs

@@ -260,8 +260,6 @@ pub enum LayoutError<'tcx> {
     NormalizationFailure(Ty<'tcx>, NormalizationError<'tcx>),
     /// A non-layout error is reported elsewhere.
     ReferencesError(ErrorGuaranteed),
-    /// A type has cyclic layout, i.e. the type contains itself without indirection.
-    Cycle(ErrorGuaranteed),
 }
 
 impl<'tcx> fmt::Display for LayoutError<'tcx> {
@@ -286,7 +284,6 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                 t,
                 e.get_type_for_failure()
             ),
-            LayoutError::Cycle(_) => write!(f, "a cycle occurred during layout computation"),
             LayoutError::ReferencesError(_) => write!(f, "the type has an unknown layout"),
         }
     }
@@ -358,8 +355,7 @@ pub fn compute(
             Err(err @ LayoutError::TooGeneric(_)) => err,
             // We can't extract SizeSkeleton info from other layout errors
             Err(
-                e @ LayoutError::Cycle(_)
-                | e @ LayoutError::Unknown(_)
+                e @ LayoutError::Unknown(_)
                 | e @ LayoutError::SizeOverflow(_)
                 | e @ LayoutError::InvalidSimd { .. }
                 | e @ LayoutError::NormalizationFailure(..)

compiler/rustc_query_impl/src/handle_cycle_error.rs

@@ -12,7 +12,6 @@
 use rustc_middle::queries::{QueryVTables, TaggedQueryKey};
 use rustc_middle::query::Cycle;
 use rustc_middle::query::erase::erase_val;
-use rustc_middle::ty::layout::LayoutError;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::def_id::{DefId, LocalDefId};
 use rustc_span::{ErrorGuaranteed, Span};
@@ -203,8 +202,7 @@ fn layout_of<'tcx>(tcx: TyCtxt<'tcx>, cycle: Cycle<'tcx>) -> &'tcx ty::layout::L
         || create_cycle_error(tcx, &cycle),
     );
 
-    let guar = diag.emit();
-    tcx.arena.alloc(LayoutError::Cycle(guar))
+    diag.emit().raise_fatal()
 }
 
 // item_and_field_ids should form a cycle where each field contains the

compiler/rustc_transmute/src/layout/tree.rs

@@ -282,7 +282,6 @@ fn from(err: &LayoutError<'tcx>) -> Self {
                 | LayoutError::InvalidSimd { .. }
                 | LayoutError::NormalizationFailure(..) => Self::UnknownLayout,
                 LayoutError::SizeOverflow(..) => Self::SizeOverflow,
-                LayoutError::Cycle(err) => Self::TypeError(*err),
             }
         }
     }

src/librustdoc/html/templates/type_layout.html

@@ -60,11 +60,6 @@
             <strong>Note:</strong> Encountered an error during type layout; {#+ #}
             the type failed to be normalized. {# #}
         </p>
-        {% when Err(LayoutError::Cycle(_)) %}
-        <p> {# #}
-            <strong>Note:</strong> Encountered an error during type layout; {#+ #}
-            the type's layout depended on the type's layout itself. {# #}
-        </p>
         {% when Err(LayoutError::InvalidSimd {..}) %}
         <p> {# #}
             <strong>Note:</strong> Encountered an error during type layout; {#+ #}

src/tools/miri/src/eval.rs

@@ -10,6 +10,7 @@
 
 use rustc_abi::ExternAbi;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::FatalErrorMarker;
 use rustc_hir::def::Namespace;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, LayoutCx};
@@ -477,7 +478,11 @@ pub fn eval_entry<'tcx>(
     let res: thread::Result<InterpResult<'_, !>> =
         panic::catch_unwind(AssertUnwindSafe(|| ecx.run_threads()));
     let res = res.unwrap_or_else(|panic_payload| {
-        ecx.handle_ice();
+        // rustc "handles" some errors by unwinding with FatalErrorMarker
+        // (after emitting suitable diagnostics), so do not treat those as ICEs.
+        if !panic_payload.is::<FatalErrorMarker>() {
+            ecx.handle_ice();
+        }
         panic::resume_unwind(panic_payload)
     });
     // Obtain the result of the execution. This is always an `Err`, but that doesn't necessarily

src/tools/miri/tests/fail/layout_cycle.rs

@@ -1,5 +1,4 @@
-//@error-in-other-file: a cycle occurred during layout computation
-//~^ ERROR: cycle detected when computing layout of
+//~ ERROR: cycle detected when computing layout of
 
 use std::mem;
 

src/tools/miri/tests/fail/layout_cycle.stderr

@@ -9,13 +9,6 @@ LL |     const SIZE: usize = intrinsics::size_of::<Self>();
    |     ^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0080]: a cycle occurred during layout computation
-  --> RUSTLIB/core/src/mem/mod.rs:LL:CC
-   |
-LL |     const SIZE: usize = intrinsics::size_of::<Self>();
-   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evaluation of `<S<S<()>> as std::mem::SizedTypeProperties>::SIZE` failed here
+error: aborting due to 1 previous error
 
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0080, E0391.
-For more information about an error, try `rustc --explain E0080`.
+For more information about this error, try `rustc --explain E0391`.

tests/ui/layout/layout-cycle.rs

@@ -1,6 +1,5 @@
 //@ build-fail
 //~^ ERROR: cycle detected when computing layout of
-//~? ERROR: a cycle occurred during layout computation
 
 // Issue #111176 -- ensure that we do not emit ICE on layout cycles
 

tests/ui/layout/layout-cycle.stderr

@@ -6,18 +6,6 @@ note: cycle used when const-evaluating + checking `core::mem::SizedTypePropertie
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0080]: a cycle occurred during layout computation
-  --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
-   |
-   = note: evaluation of `<S<S<()>> as std::mem::SizedTypeProperties>::SIZE` failed here
+error: aborting due to 1 previous error
 
-note: the above error was encountered while instantiating `fn std::mem::size_of::<S<S<()>>>`
-  --> $DIR/layout-cycle.rs:26:5
-   |
-LL |     mem::size_of::<S<T>>()
-   |     ^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0080, E0391.
-For more information about an error, try `rustc --explain E0080`.
+For more information about this error, try `rustc --explain E0391`.

tests/ui/layout/post-mono-layout-cycle.stderr

@@ -5,12 +5,6 @@ error[E0391]: cycle detected when computing layout of `Wrapper<()>`
    = note: cycle used when computing layout of `core::option::Option<Wrapper<()>>`
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-note: the above error was encountered while instantiating `fn abi::<()>`
-  --> $DIR/post-mono-layout-cycle.rs:19:5
-   |
-LL |     abi::<T>(None);
-   |     ^^^^^^^^^^^^^^
-
 error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0391`.

tests/ui/sized/stack-overflow-trait-infer-98842.64bit.stderr

@@ -1,21 +0,0 @@
-error[E0391]: cycle detected when computing layout of `Foo`
-   |
-   = note: ...which requires computing layout of `<&'static Foo as core::ops::deref::Deref>::Target`...
-   = note: ...which again requires computing layout of `Foo`, completing the cycle
-note: cycle used when const-evaluating + checking `_`
-  --> $DIR/stack-overflow-trait-infer-98842.rs:14:1
-   |
-LL | const _: *const Foo = 0 as _;
-   | ^^^^^^^^^^^^^^^^^^^
-   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
-
-error[E0080]: a cycle occurred during layout computation
-  --> $DIR/stack-overflow-trait-infer-98842.rs:14:1
-   |
-LL | const _: *const Foo = 0 as _;
-   | ^^^^^^^^^^^^^^^^^^^ evaluation of `_` failed here
-
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0080, E0391.
-For more information about an error, try `rustc --explain E0080`.

tests/ui/sized/stack-overflow-trait-infer-98842.rs

@@ -2,8 +2,7 @@
 // issue: rust-lang/rust#98842
 //@ check-fail
 //@ edition:2021
-//@ stderr-per-bitwidth
-//~^^^^^ ERROR cycle detected when computing layout of `Foo`
+//~^^^^ ERROR cycle detected when computing layout of `Foo`
 
 // If the inner `Foo` is named through an associated type,
 // the "infinite size" error does not occur.
@@ -12,6 +11,5 @@
 // and it will infinitely recurse somewhere trying to figure out the
 // size of this pointer (is my guess):
 const _: *const Foo = 0 as _;
-//~^ ERROR a cycle occurred during layout computation
 
 pub fn main() {}

tests/ui/sized/stack-overflow-trait-infer-98842.stderr

@@ -3,19 +3,12 @@ error[E0391]: cycle detected when computing layout of `Foo`
    = note: ...which requires computing layout of `<&'static Foo as core::ops::deref::Deref>::Target`...
    = note: ...which again requires computing layout of `Foo`, completing the cycle
 note: cycle used when const-evaluating + checking `_`
-  --> $DIR/stack-overflow-trait-infer-98842.rs:14:1
+  --> $DIR/stack-overflow-trait-infer-98842.rs:13:1
    |
 LL | const _: *const Foo = 0 as _;
    | ^^^^^^^^^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
-error[E0080]: a cycle occurred during layout computation
-  --> $DIR/stack-overflow-trait-infer-98842.rs:14:1
-   |
-LL | const _: *const Foo = 0 as _;
-   | ^^^^^^^^^^^^^^^^^^^ evaluation of `_` failed here
+error: aborting due to 1 previous error
 
-error: aborting due to 2 previous errors
-
-Some errors have detailed explanations: E0080, E0391.
-For more information about an error, try `rustc --explain E0080`.
+For more information about this error, try `rustc --explain E0391`.