Rollup merge of #117159 - oli-obk:error_shenanigans, r=estebank

Work around the fact that `check_mod_type_wf` may spuriously return `ErrorGuaranteed`

Even if that error is only emitted by `check_mod_item_types`.

fixes #117153

A cleaner refactoring would merge/chain these queries in ways that ensure we only actually get an `ErrorGuaranteed` if there was an error emitted.

Author: matthiaskrgr

compiler/rustc_hir_analysis/src/check/check.rs

@@ -128,7 +128,11 @@ fn check_union_fields(tcx: TyCtxt<'_>, span: Span, item_def_id: LocalDefId) -> b
 
         let param_env = tcx.param_env(item_def_id);
         for field in &def.non_enum_variant().fields {
-            let field_ty = tcx.normalize_erasing_regions(param_env, field.ty(tcx, args));
+            let Ok(field_ty) = tcx.try_normalize_erasing_regions(param_env, field.ty(tcx, args))
+            else {
+                tcx.sess.delay_span_bug(span, "could not normalize field type");
+                continue;
+            };
 
             if !allowed_union_field(field_ty, tcx, param_env) {
                 let (field_span, ty_span) = match tcx.hir().get_if_local(field.did) {

compiler/rustc_hir_analysis/src/lib.rs

@@ -205,15 +205,19 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
         })?;
     }
 
-    tcx.sess.time("wf_checking", || {
+    let errs = tcx.sess.time("wf_checking", || {
         tcx.hir().try_par_for_each_module(|module| tcx.ensure().check_mod_type_wf(module))
-    })?;
+    });
 
     // NOTE: This is copy/pasted in librustdoc/core.rs and should be kept in sync.
     tcx.sess.time("item_types_checking", || {
         tcx.hir().for_each_module(|module| tcx.ensure().check_mod_item_types(module))
     });
 
+    // HACK: `check_mod_type_wf` may spuriously emit errors due to `delay_span_bug`, even if those errors
+    // only actually get emitted in `check_mod_item_types`.
+    errs?;
+
     if tcx.features().rustc_attrs {
         tcx.sess.track_errors(|| collect::test_opaque_hidden_types(tcx))?;
     }

src/tools/clippy/tests/ui/crashes/ice-6252.stderr

@@ -24,6 +24,16 @@ help: you might be missing a type parameter
 LL | impl<N, M, VAL> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
    |          +++++
 
-error: aborting due to 2 previous errors
+error[E0046]: not all trait items implemented, missing: `VAL`
+  --> $DIR/ice-6252.rs:11:1
+   |
+LL |     const VAL: T;
+   |     ------------ `VAL` from trait
+...
+LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `VAL` in implementation
+
+error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0412`.
+Some errors have detailed explanations: E0046, E0412.
+For more information about an error, try `rustc --explain E0046`.

tests/ui/associated-consts/issue-105330.rs

@@ -14,5 +14,6 @@ fn foo<A: TraitWAssocConst<A=32>>() { //~ ERROR E0658
 
 fn main<A: TraitWAssocConst<A=32>>() {
     //~^ ERROR E0658
+    //~| ERROR E0131
     foo::<Demo>();
 }

tests/ui/associated-consts/issue-105330.stderr

@@ -39,7 +39,13 @@ error[E0562]: `impl Trait` only allowed in function and inherent method argument
 LL | impl TraitWAssocConst for impl Demo {
    |                           ^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error[E0131]: `main` function is not allowed to have generic parameters
+  --> $DIR/issue-105330.rs:15:8
+   |
+LL | fn main<A: TraitWAssocConst<A=32>>() {
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `main` cannot have generic parameters
+
+error: aborting due to 6 previous errors
 
-Some errors have detailed explanations: E0404, E0562, E0658.
-For more information about an error, try `rustc --explain E0404`.
+Some errors have detailed explanations: E0131, E0404, E0562, E0658.
+For more information about an error, try `rustc --explain E0131`.

tests/ui/associated-inherent-types/generic-associated-types-bad.item.stderr

@@ -10,6 +10,18 @@ note: required by a bound in `Ty::Pr`
 LL |     type Pr<T: Copy> = T;
    |                ^^^^ required by this bound in `Ty::Pr`
 
-error: aborting due to previous error
+error[E0277]: the trait bound `String: Copy` is not satisfied
+  --> $DIR/generic-associated-types-bad.rs:16:27
+   |
+LL | const _: Ty::Pr<String> = String::new();
+   |                           ^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |
+note: required by a bound in `Ty::Pr`
+  --> $DIR/generic-associated-types-bad.rs:10:16
+   |
+LL |     type Pr<T: Copy> = T;
+   |                ^^^^ required by this bound in `Ty::Pr`
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/associated-inherent-types/generic-associated-types-bad.local.stderr

@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `Vec<()>: Copy` is not satisfied
-  --> $DIR/generic-associated-types-bad.rs:20:12
+  --> $DIR/generic-associated-types-bad.rs:21:12
    |
 LL |     let _: Ty::Pr<Vec<()>>;
    |            ^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `Vec<()>`

tests/ui/associated-inherent-types/generic-associated-types-bad.region.stderr

@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/generic-associated-types-bad.rs:25:12
+  --> $DIR/generic-associated-types-bad.rs:26:12
    |
 LL | fn user<'a>() {
    |         -- lifetime `'a` defined here

tests/ui/associated-inherent-types/generic-associated-types-bad.rs

@@ -14,6 +14,7 @@ impl Ty {
 
 #[cfg(item)]
 const _: Ty::Pr<String> = String::new(); //[item]~ the trait bound `String: Copy` is not satisfied
+//[item]~^ the trait bound `String: Copy` is not satisfied
 
 fn main() {
     #[cfg(local)]

tests/ui/associated-types/associated-types-no-suitable-supertrait.rs

@@ -21,6 +21,7 @@ trait Other {
 impl<T:Get> Other for T {
     fn uhoh<U:Get>(&self, foo: U, bar: <(T, U) as Get>::Value) {}
     //~^ ERROR the trait bound `(T, U): Get` is not satisfied
+    //~| ERROR the trait bound `(T, U): Get` is not satisfied
 }
 
 fn main() { }

tests/ui/associated-types/associated-types-no-suitable-supertrait.stderr

@@ -21,6 +21,18 @@ help: consider further restricting `Self`
 LL |     fn uhoh<U:Get>(&self, foo: U, bar: <Self as Get>::Value) where Self: Get {}
    |                                                              +++++++++++++++
 
-error: aborting due to 2 previous errors
+error[E0277]: the trait bound `(T, U): Get` is not satisfied
+  --> $DIR/associated-types-no-suitable-supertrait.rs:22:5
+   |
+LL |     fn uhoh<U:Get>(&self, foo: U, bar: <(T, U) as Get>::Value) {}
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Get` is not implemented for `(T, U)`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/associated-types-no-suitable-supertrait.rs:12:1
+   |
+LL | trait Get {
+   | ^^^^^^^^^
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/coherence/coherence-impl-trait-for-trait-object-safe.rs

@@ -6,5 +6,6 @@
 trait NotObjectSafe { fn eq(&self, other: Self); }
 impl NotObjectSafe for dyn NotObjectSafe { }
 //~^ ERROR E0038
+//~| ERROR E0046
 
 fn main() { }

tests/ui/coherence/coherence-impl-trait-for-trait-object-safe.stderr

@@ -13,6 +13,15 @@ LL | trait NotObjectSafe { fn eq(&self, other: Self); }
    |       this trait cannot be made into an object...
    = help: consider moving `eq` to another trait
 
-error: aborting due to previous error
+error[E0046]: not all trait items implemented, missing: `eq`
+  --> $DIR/coherence-impl-trait-for-trait-object-safe.rs:7:1
+   |
+LL | trait NotObjectSafe { fn eq(&self, other: Self); }
+   |                       -------------------------- `eq` from trait
+LL | impl NotObjectSafe for dyn NotObjectSafe { }
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `eq` in implementation
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0038`.
+Some errors have detailed explanations: E0038, E0046.
+For more information about an error, try `rustc --explain E0038`.

tests/ui/const-generics/generic_const_exprs/type_mismatch.rs

@@ -0,0 +1,13 @@
+#![feature(generic_const_exprs)]
+#![allow(incomplete_features)]
+
+trait Q {
+    const ASSOC: usize;
+}
+
+impl<const N: u64> Q for [u8; N] {}
+//~^ ERROR not all trait items implemented
+
+pub fn q_user() -> [u8; <[u8; 13] as Q>::ASSOC] {}
+
+pub fn main() {}

tests/ui/const-generics/generic_const_exprs/type_mismatch.stderr

@@ -0,0 +1,12 @@
+error[E0046]: not all trait items implemented, missing: `ASSOC`
+  --> $DIR/type_mismatch.rs:8:1
+   |
+LL |     const ASSOC: usize;
+   |     ------------------ `ASSOC` from trait
+...
+LL | impl<const N: u64> Q for [u8; N] {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `ASSOC` in implementation
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0046`.

tests/ui/consts/const-unsized.rs

@@ -2,15 +2,19 @@ use std::fmt::Debug;
 
 const CONST_0: dyn Debug + Sync = *(&0 as &(dyn Debug + Sync));
 //~^ ERROR the size for values of type
+//~| ERROR the size for values of type
 
 const CONST_FOO: str = *"foo";
 //~^ ERROR the size for values of type
+//~| ERROR the size for values of type
 
 static STATIC_1: dyn Debug + Sync = *(&1 as &(dyn Debug + Sync));
 //~^ ERROR the size for values of type
+//~| ERROR the size for values of type
 
 static STATIC_BAR: str = *"bar";
 //~^ ERROR the size for values of type
+//~| ERROR the size for values of type
 
 fn main() {
     println!("{:?} {:?} {:?} {:?}", &CONST_0, &CONST_FOO, &STATIC_1, &STATIC_BAR);

tests/ui/consts/const-unsized.stderr

@@ -7,29 +7,65 @@ LL | const CONST_0: dyn Debug + Sync = *(&0 as &(dyn Debug + Sync));
    = help: the trait `Sized` is not implemented for `(dyn Debug + Sync + 'static)`
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
-  --> $DIR/const-unsized.rs:6:18
+  --> $DIR/const-unsized.rs:7:18
    |
 LL | const CONST_FOO: str = *"foo";
    |                  ^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
 
 error[E0277]: the size for values of type `(dyn Debug + Sync + 'static)` cannot be known at compilation time
-  --> $DIR/const-unsized.rs:9:18
+  --> $DIR/const-unsized.rs:11:18
    |
 LL | static STATIC_1: dyn Debug + Sync = *(&1 as &(dyn Debug + Sync));
    |                  ^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `(dyn Debug + Sync + 'static)`
 
 error[E0277]: the size for values of type `str` cannot be known at compilation time
-  --> $DIR/const-unsized.rs:12:20
+  --> $DIR/const-unsized.rs:15:20
    |
 LL | static STATIC_BAR: str = *"bar";
    |                    ^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `str`
 
-error: aborting due to 4 previous errors
+error[E0277]: the size for values of type `(dyn Debug + Sync + 'static)` cannot be known at compilation time
+  --> $DIR/const-unsized.rs:3:35
+   |
+LL | const CONST_0: dyn Debug + Sync = *(&0 as &(dyn Debug + Sync));
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `(dyn Debug + Sync + 'static)`
+   = note: constant expressions must have a statically known size
+
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/const-unsized.rs:7:24
+   |
+LL | const CONST_FOO: str = *"foo";
+   |                        ^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `str`
+   = note: constant expressions must have a statically known size
+
+error[E0277]: the size for values of type `(dyn Debug + Sync + 'static)` cannot be known at compilation time
+  --> $DIR/const-unsized.rs:11:37
+   |
+LL | static STATIC_1: dyn Debug + Sync = *(&1 as &(dyn Debug + Sync));
+   |                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `(dyn Debug + Sync + 'static)`
+   = note: constant expressions must have a statically known size
+
+error[E0277]: the size for values of type `str` cannot be known at compilation time
+  --> $DIR/const-unsized.rs:15:26
+   |
+LL | static STATIC_BAR: str = *"bar";
+   |                          ^^^^^^ doesn't have a size known at compile-time
+   |
+   = help: the trait `Sized` is not implemented for `str`
+   = note: constant expressions must have a statically known size
+
+error: aborting due to 8 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

tests/ui/generic-associated-types/issue-84931.rs

@@ -12,7 +12,8 @@ struct StreamingSliceIter<'a, T> {
 
 impl<'b, T: 'b> StreamingIter for StreamingSliceIter<'b, T> {
     type Item<'a> = &'a mut T;
-    //~^ the parameter type
+    //~^ ERROR: the parameter type
+    //~| ERROR: does not fulfill the required lifetime
     fn next(&mut self) -> Option<&mut T> {
         loop {}
     }

tests/ui/generic-associated-types/issue-84931.stderr

@@ -11,6 +11,26 @@ help: consider adding an explicit lifetime bound
 LL |     type Item<'a> = &'a mut T where T: 'a;
    |                               +++++++++++
 
-error: aborting due to previous error
+error[E0477]: the type `StreamingSliceIter<'b, T>` does not fulfill the required lifetime
+  --> $DIR/issue-84931.rs:14:21
+   |
+LL |     type Item<'a> where Self: 'a;
+   |     ------------- definition of `Item` from trait
+...
+LL |     type Item<'a> = &'a mut T;
+   |                     ^^^^^^^^^
+   |
+note: type must outlive the lifetime `'a` as defined here
+  --> $DIR/issue-84931.rs:14:15
+   |
+LL |     type Item<'a> = &'a mut T;
+   |               ^^
+help: copy the `where` clause predicates from the trait
+   |
+LL |     type Item<'a> = &'a mut T where Self: 'a;
+   |                               ++++++++++++++
+
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0309`.
+Some errors have detailed explanations: E0309, E0477.
+For more information about an error, try `rustc --explain E0309`.

tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.rs

@@ -7,6 +7,7 @@ pub trait X {
 
 impl X for () {
     type Y<'a> = &'a ();
+    //~^ ERROR lifetime bound not satisfied
 }
 
 struct B<'a, T: for<'r> X<Y<'r> = &'r ()>> {