Avoid follow-up errors and ICEs after missing lifetime errors on data structures

Author: oli-obk

Diff for: .gitignore

@@ -50,6 +50,7 @@ build/
 /target
 /src/bootstrap/target
 /src/tools/x/target
+/inc-fat/
 # Created by default with `src/ci/docker/run.sh`
 /obj/
 /rustc-ice*

Diff for: compiler/rustc_infer/src/infer/mod.rs

@@ -1264,6 +1264,9 @@ impl<'tcx> InferCtxt<'tcx> {
     where
         T: TypeFoldable<TyCtxt<'tcx>>,
     {
+        if let Err(guar) = value.error_reported() {
+            self.set_tainted_by_errors(guar);
+        }
         if !value.has_non_region_infer() {
             return value;
         }

Diff for: tests/crashes/124083.rs

@@ -4,7 +4,6 @@ pub struct Foo<'a, 'b, T> {
     field1: dyn Bar<'a, 'b>,
     //~^ ERROR
     //~| ERROR
-    //~| ERROR
 }
 
 pub trait Bar<'x, 's, U>

Diff for: tests/crashes/124262.rs

@@ -5,7 +5,7 @@ LL |     field1: dyn Bar<'a, 'b>,
    |                 ^^^ expected 1 generic argument
    |
 note: trait defined here, with 1 generic parameter: `U`
-  --> $DIR/unable-fulfill-trait.rs:10:11
+  --> $DIR/unable-fulfill-trait.rs:9:11
    |
 LL | pub trait Bar<'x, 's, U>
    |           ^^^         -
@@ -20,24 +20,7 @@ error[E0227]: ambiguous lifetime bound, explicit lifetime bound required
 LL |     field1: dyn Bar<'a, 'b>,
    |             ^^^^^^^^^^^^^^^
 
-error[E0478]: lifetime bound not satisfied
-  --> $DIR/unable-fulfill-trait.rs:4:13
-   |
-LL |     field1: dyn Bar<'a, 'b>,
-   |             ^^^^^^^^^^^^^^^
-   |
-note: lifetime parameter instantiated with the lifetime `'b` as defined here
-  --> $DIR/unable-fulfill-trait.rs:3:20
-   |
-LL | pub struct Foo<'a, 'b, T> {
-   |                    ^^
-note: but lifetime parameter must outlive the lifetime `'a` as defined here
-  --> $DIR/unable-fulfill-trait.rs:3:16
-   |
-LL | pub struct Foo<'a, 'b, T> {
-   |                ^^
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0107, E0227, E0478.
+Some errors have detailed explanations: E0107, E0227.
 For more information about an error, try `rustc --explain E0107`.

Diff for: tests/crashes/125155.rs

@@ -7,25 +7,13 @@ LL |     pub fn call_me<Args: Sized, const IDX: usize, const FN: unsafe extern "
    = note: type parameters may not be used in the type of const parameters
 
 error[E0770]: the type of const parameters must not depend on other generic parameters
-  --> $DIR/issue-71381.rs:24:40
+  --> $DIR/issue-71381.rs:23:40
    |
 LL |         const FN: unsafe extern "C" fn(Args),
    |                                        ^^^^ the type must not depend on the parameter `Args`
    |
    = note: type parameters may not be used in the type of const parameters
 
-error[E0594]: cannot assign to `self.0`, which is behind a `&` reference
-  --> $DIR/issue-71381.rs:17:9
-   |
-LL |         self.0 = Self::trampiline::<Args, IDX, FN> as _
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self` is a `&` reference, so the data it refers to cannot be written
-   |
-help: consider changing this to be a mutable reference
-   |
-LL |     pub fn call_me<Args: Sized, const IDX: usize, const FN: unsafe extern "C" fn(Args)>(&mut self) {
-   |                                                                                         ~~~~~~~~~
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0594, E0770.
-For more information about an error, try `rustc --explain E0594`.
+For more information about this error, try `rustc --explain E0770`.

Diff for: tests/crashes/125888.rs

@@ -7,7 +7,7 @@ LL |     pub fn call_me<Args: Sized, const IDX: usize, const FN: unsafe extern "
    = note: type parameters may not be used in the type of const parameters
 
 error[E0770]: the type of const parameters must not depend on other generic parameters
-  --> $DIR/issue-71381.rs:24:40
+  --> $DIR/issue-71381.rs:23:40
    |
 LL |         const FN: unsafe extern "C" fn(Args),
    |                                        ^^^^ the type must not depend on the parameter `Args`
@@ -23,25 +23,13 @@ LL |     pub fn call_me<Args: Sized, const IDX: usize, const FN: unsafe extern "
    = note: the only supported types are integers, `bool` and `char`
 
 error: using function pointers as const generic parameters is forbidden
-  --> $DIR/issue-71381.rs:24:19
+  --> $DIR/issue-71381.rs:23:19
    |
 LL |         const FN: unsafe extern "C" fn(Args),
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool` and `char`
 
-error[E0594]: cannot assign to `self.0`, which is behind a `&` reference
-  --> $DIR/issue-71381.rs:17:9
-   |
-LL |         self.0 = Self::trampiline::<Args, IDX, FN> as _
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `self` is a `&` reference, so the data it refers to cannot be written
-   |
-help: consider changing this to be a mutable reference
-   |
-LL |     pub fn call_me<Args: Sized, const IDX: usize, const FN: unsafe extern "C" fn(Args)>(&mut self) {
-   |                                                                                         ~~~~~~~~~
-
-error: aborting due to 5 previous errors
+error: aborting due to 4 previous errors
 
-Some errors have detailed explanations: E0594, E0770.
-For more information about an error, try `rustc --explain E0594`.
+For more information about this error, try `rustc --explain E0770`.

Diff for: tests/crashes/125992.rs

@@ -15,7 +15,6 @@ impl Test {
         //~^ ERROR: the type of const parameters must not depend on other generic parameters
         //[min]~^^ ERROR: using function pointers as const generic parameters is forbidden
         self.0 = Self::trampiline::<Args, IDX, FN> as _
-        //~^ ERROR: cannot assign to `self.0`
     }
 
     unsafe extern "C" fn trampiline<

Diff for: tests/crashes/126648.rs

@@ -15,7 +15,6 @@ fn gather_from_file(dir_entry: &foo::MissingItem) -> impl Iterator<Item = Lint>
 
 fn lint_files() -> impl Iterator<Item = foo::MissingItem> {
     //~^ ERROR: failed to resolve
-    //~| ERROR: `()` is not an iterator
     unimplemented!()
 }
 

Diff for: tests/crashes/126666.rs

@@ -1,11 +1,3 @@
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-72911.rs:16:20
-   |
-LL | fn lint_files() -> impl Iterator<Item = foo::MissingItem> {
-   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
 error[E0433]: failed to resolve: use of undeclared crate or module `foo`
   --> $DIR/issue-72911.rs:11:33
    |
@@ -18,7 +10,6 @@ error[E0433]: failed to resolve: use of undeclared crate or module `foo`
 LL | fn lint_files() -> impl Iterator<Item = foo::MissingItem> {
    |                                         ^^^ use of undeclared crate or module `foo`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0277, E0433.
-For more information about an error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0433`.

Diff for: tests/crashes/127266.rs

@@ -9,7 +9,6 @@ impl<T, S: Iterator<Item = T>> Iterator for ChunkingIterator<T, S> {
     type Item = IteratorChunk<T, S>; //~ ERROR missing lifetime
 
     fn next(&mut self) -> Option<IteratorChunk<T, S>> {
-        //~^ ERROR `impl` item signature doesn't match `trait` item signature
         todo!()
     }
 }

Diff for: tests/crashes/127304.rs

@@ -9,20 +9,6 @@ help: consider introducing a named lifetime parameter
 LL |     type Item<'a> = IteratorChunk<'a, T, S>;
    |              ++++                 +++
 
-error: `impl` item signature doesn't match `trait` item signature
-  --> $DIR/issue-74918-missing-lifetime.rs:11:5
-   |
-LL |     fn next(&mut self) -> Option<IteratorChunk<T, S>> {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ found `fn(&'1 mut ChunkingIterator<T, S>) -> Option<IteratorChunk<'1, T, S>>`
-  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
-   |
-   = note: expected `fn(&'1 mut ChunkingIterator<T, S>) -> Option<IteratorChunk<'2, T, S>>`
-   |
-   = note: expected signature `fn(&'1 mut ChunkingIterator<T, S>) -> Option<IteratorChunk<'2, T, S>>`
-              found signature `fn(&'1 mut ChunkingIterator<T, S>) -> Option<IteratorChunk<'1, T, S>>`
-   = help: the lifetime requirements from the `impl` do not correspond to the requirements in the `trait`
-   = help: verify the lifetime relationships in the `trait` and `impl` between the `self` argument, the other inputs and its output
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
 For more information about this error, try `rustc --explain E0106`.

Diff for: tests/rustdoc-ui/unable-fulfill-trait.rs

@@ -0,0 +1,9 @@
+//! This test checks that we taint typeck results when there are
+//! error lifetimes, even though typeck doesn't actually care about lifetimes.
+
+struct Slice(&'reborrow [&'static [u8]]);
+//~^ ERROR undeclared lifetime
+
+static MAP: Slice = Slice(&[b"" as &'static [u8]]);
+
+fn main() {}

Diff for: tests/rustdoc-ui/unable-fulfill-trait.stderr

@@ -0,0 +1,11 @@
+error[E0261]: use of undeclared lifetime name `'reborrow`
+  --> $DIR/missing_lifetime.rs:4:15
+   |
+LL | struct Slice(&'reborrow [&'static [u8]]);
+   |             - ^^^^^^^^^ undeclared lifetime
+   |             |
+   |             help: consider introducing lifetime `'reborrow` here: `<'reborrow>`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0261`.