Work around the fact that check_mod_type_wf may spuriously return ErrorGuaranteed, even if that error is only emitted by check_modwitem_types

Author: oli-obk

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() { }