Auto merge of rust-lang#127311 - oli-obk:do_not_count_errors, r=<try>

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

Tuple struct constructors are functions, so when we call them typeck will use the signature tuple struct constructor function to provide type hints. Since typeck mostly ignores and erases lifetimes, we end up never seeing the error lifetime in writeback, thus not tainting the typeck result.

Now, we eagerly taint typeck results by tainting from `resolve_vars_if_possible`, which is called all over the place.

I did not carry over all the `crashes` test suite tests, as they are really all the same cause (missing or unknown lifetime names in tuple struct definitions or generic arg lists).

fixes rust-lang#124262
fixes rust-lang#124083
fixes rust-lang#125155
fixes rust-lang#125888
fixes rust-lang#125992
fixes rust-lang#126666
fixes rust-lang#126648
fixes rust-lang#127268

compiler/rustc_infer/src/infer/mod.rs

@@ -1273,6 +1273,9 @@ 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;
         }

tests/rustdoc-ui/unable-fulfill-trait.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>

tests/rustdoc-ui/unable-fulfill-trait.stderr

@@ -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`.

tests/ui/const-generics/issues/issue-62878.min.stderr

@@ -30,31 +30,7 @@ help: add `#![feature(generic_arg_infer)]` to the crate attributes to enable
 LL + #![feature(generic_arg_infer)]
    |
 
-error[E0284]: type annotations needed
-  --> $DIR/issue-62878.rs:10:5
-   |
-LL |     foo::<_, { [1] }>();
-   |     ^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the function `foo`
-   |
-note: required by a const generic parameter in `foo`
-  --> $DIR/issue-62878.rs:5:8
-   |
-LL | fn foo<const N: usize, const A: [u8; N]>() {}
-   |        ^^^^^^^^^^^^^^ required by this const generic parameter in `foo`
-
-error[E0284]: type annotations needed
-  --> $DIR/issue-62878.rs:10:5
-   |
-LL |     foo::<_, { [1] }>();
-   |     ^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `A` declared on the function `foo`
-   |
-note: required by a const generic parameter in `foo`
-  --> $DIR/issue-62878.rs:5:24
-   |
-LL | fn foo<const N: usize, const A: [u8; N]>() {}
-   |                        ^^^^^^^^^^^^^^^^ required by this const generic parameter in `foo`
-
-error: aborting due to 5 previous errors
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0284, E0747, E0770.
-For more information about an error, try `rustc --explain E0284`.
+Some errors have detailed explanations: E0747, E0770.
+For more information about an error, try `rustc --explain E0747`.

tests/ui/const-generics/issues/issue-62878.rs

@@ -9,6 +9,4 @@ fn foo<const N: usize, const A: [u8; N]>() {}
 fn main() {
     foo::<_, { [1] }>();
     //[min]~^ ERROR: type provided when a constant was expected
-    //[min]~| ERROR type annotations needed
-    //[min]~| ERROR type annotations needed
 }

tests/ui/const-generics/issues/issue-71381.full.stderr

@@ -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`.

tests/ui/const-generics/issues/issue-71381.min.stderr

@@ -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`.

tests/ui/const-generics/issues/issue-71381.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<

tests/ui/const-generics/min_const_generics/macro-fail.rs

@@ -16,7 +16,6 @@ fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
   //~| ERROR: type provided when a constant was expected
   Example::<gimme_a_const!(marker)>
   //~^ ERROR: type provided when a constant was expected
-  //~| ERROR type annotations needed
 }
 
 fn from_marker(_: impl Marker<{

tests/ui/const-generics/min_const_generics/macro-fail.stderr

@@ -1,5 +1,5 @@
 error: expected type, found `{`
-  --> $DIR/macro-fail.rs:31:27
+  --> $DIR/macro-fail.rs:30:27
    |
 LL | fn make_marker() -> impl Marker<gimme_a_const!(marker)> {
    |                                 ----------------------
@@ -13,7 +13,7 @@ LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
    = note: this error originates in the macro `gimme_a_const` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: expected type, found `{`
-  --> $DIR/macro-fail.rs:31:27
+  --> $DIR/macro-fail.rs:30:27
    |
 LL |   Example::<gimme_a_const!(marker)>
    |             ----------------------
@@ -41,7 +41,7 @@ LL |   let _fail = Example::<external_macro!()>;
    = note: this error originates in the macro `external_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: unexpected end of macro invocation
-  --> $DIR/macro-fail.rs:42:25
+  --> $DIR/macro-fail.rs:41:25
    |
 LL |     macro_rules! gimme_a_const {
    |     -------------------------- when calling this macro
@@ -50,7 +50,7 @@ LL |   let _fail = Example::<gimme_a_const!()>;
    |                         ^^^^^^^^^^^^^^^^ missing tokens in macro arguments
    |
 note: while trying to match meta-variable `$rusty:ident`
-  --> $DIR/macro-fail.rs:31:8
+  --> $DIR/macro-fail.rs:30:8
    |
 LL |       ($rusty: ident) => {{ let $rusty = 3; *&$rusty }}
    |        ^^^^^^^^^^^^^
@@ -75,32 +75,20 @@ error[E0747]: type provided when a constant was expected
 LL |   Example::<gimme_a_const!(marker)>
    |             ^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0284]: type annotations needed
-  --> $DIR/macro-fail.rs:17:3
-   |
-LL |   Example::<gimme_a_const!(marker)>
-   |   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer the value of the const parameter `N` declared on the struct `Example`
-   |
-note: required by a const generic parameter in `Example`
-  --> $DIR/macro-fail.rs:1:16
-   |
-LL | struct Example<const N: usize>;
-   |                ^^^^^^^^^^^^^^ required by this const generic parameter in `Example`
-
 error[E0747]: type provided when a constant was expected
-  --> $DIR/macro-fail.rs:38:25
+  --> $DIR/macro-fail.rs:37:25
    |
 LL |   let _fail = Example::<external_macro!()>;
    |                         ^^^^^^^^^^^^^^^^^
 
 error[E0747]: type provided when a constant was expected
-  --> $DIR/macro-fail.rs:42:25
+  --> $DIR/macro-fail.rs:41:25
    |
 LL |   let _fail = Example::<gimme_a_const!()>;
    |                         ^^^^^^^^^^^^^^^^
 
 error[E0284]: type annotations needed for `Example<_>`
-  --> $DIR/macro-fail.rs:38:7
+  --> $DIR/macro-fail.rs:37:7
    |
 LL |   let _fail = Example::<external_macro!()>;
    |       ^^^^^   ---------------------------- type must be known at this point
@@ -116,7 +104,7 @@ LL |   let _fail: Example<N> = Example::<external_macro!()>;
    |            ++++++++++++
 
 error[E0284]: type annotations needed for `Example<_>`
-  --> $DIR/macro-fail.rs:42:7
+  --> $DIR/macro-fail.rs:41:7
    |
 LL |   let _fail = Example::<gimme_a_const!()>;
    |       ^^^^^   --------------------------- type must be known at this point
@@ -131,7 +119,7 @@ help: consider giving `_fail` an explicit type, where the value of const paramet
 LL |   let _fail: Example<N> = Example::<gimme_a_const!()>;
    |            ++++++++++++
 
-error: aborting due to 12 previous errors
+error: aborting due to 11 previous errors
 
 Some errors have detailed explanations: E0284, E0747.
 For more information about an error, try `rustc --explain E0284`.

tests/ui/impl-trait/issue-72911.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!()
 }
 

tests/ui/impl-trait/issue-72911.stderr

@@ -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`.