Auto merge of #56999 - petrochenkov:macrecov2, r=estebank

AST/HIR: Introduce `ExprKind::Err` for better error recovery in the front-end

This way we can avoid aborting compilation if expansion produces errors and generate `ExprKind::Err`s instead.

22 files changed, 86 insertions, 37 deletions

diff --git a/src/test/ui/issues/issue-10536.rs b/src/test/ui/issues/issue-10536.rs
index f8695caca5b..95c8c2b0585 100644
--- a/src/test/ui/issues/issue-10536.rs
+++ b/src/test/ui/issues/issue-10536.rs
@@ -1,8 +1,6 @@
 // We only want to assert that this doesn't ICE, we don't particularly care
 // about whether it nor it fails to compile.
 
-// error-pattern:
-
 macro_rules! foo{
     () => {{
         macro_rules! bar{() => (())}
@@ -15,9 +13,11 @@ pub fn main() {
 
     assert!({one! two()});
     //~^ ERROR macros that expand to items must either be surrounded with braces or followed by a
+    //~| ERROR cannot find macro `one!` in this scope
+    //~| ERROR mismatched types
 
     // regardless of whether nested macro_rules works, the following should at
     // least throw a conventional error.
     assert!({one! two});
-    //~^ ERROR expected
+    //~^ ERROR expected `(` or `{`, found `}`
 }
diff --git a/src/test/ui/issues/issue-10536.stderr b/src/test/ui/issues/issue-10536.stderr
index bc542ce35c0..d5caf777cd4 100644
--- a/src/test/ui/issues/issue-10536.stderr
+++ b/src/test/ui/issues/issue-10536.stderr
@@ -1,5 +1,5 @@
 error: macros that expand to items must either be surrounded with braces or followed by a semicolon
-  --> $DIR/issue-10536.rs:16:22
+  --> $DIR/issue-10536.rs:14:22
    |
 LL |     assert!({one! two()});
    |                      ^^
@@ -10,5 +10,21 @@ error: expected `(` or `{`, found `}`
 LL |     assert!({one! two});
    |                      ^ expected `(` or `{`
 
-error: aborting due to 2 previous errors
+error: cannot find macro `one!` in this scope
+  --> $DIR/issue-10536.rs:14:14
+   |
+LL |     assert!({one! two()});
+   |              ^^^
+
+error[E0308]: mismatched types
+  --> $DIR/issue-10536.rs:14:13
+   |
+LL |     assert!({one! two()});
+   |             ^^^^^^^^^^^^ expected bool, found ()
+   |
+   = note: expected type `bool`
+              found type `()`
+
+error: aborting due to 4 previous errors
 
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/issues/issue-11692-1.rs b/src/test/ui/issues/issue-11692-1.rs
index eae555ad83c..22777780402 100644
--- a/src/test/ui/issues/issue-11692-1.rs
+++ b/src/test/ui/issues/issue-11692-1.rs
@@ -1,4 +1,5 @@
 fn main() {
     print!(testo!());
     //~^ ERROR: format argument must be a string literal
+    //~| ERROR: cannot find macro `testo!` in this scope
 }
diff --git a/src/test/ui/issues/issue-11692-1.stderr b/src/test/ui/issues/issue-11692-1.stderr
index 1173e056321..f4cc825803a 100644
--- a/src/test/ui/issues/issue-11692-1.stderr
+++ b/src/test/ui/issues/issue-11692-1.stderr
@@ -8,5 +8,11 @@ help: you might be missing a string literal to format with
 LL |     print!("{}", testo!());
    |            ^^^^^
 
-error: aborting due to previous error
+error: cannot find macro `testo!` in this scope
+  --> $DIR/issue-11692-1.rs:2:12
+   |
+LL |     print!(testo!());
+   |            ^^^^^
+
+error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-11692-2.rs b/src/test/ui/issues/issue-11692-2.rs
index 61be284d732..61039316573 100644
--- a/src/test/ui/issues/issue-11692-2.rs
+++ b/src/test/ui/issues/issue-11692-2.rs
@@ -1,3 +1,4 @@
 fn main() {
     concat!(test!()); //~ ERROR cannot find macro `test!` in this scope
+                      //~| ERROR expected a literal
 }
diff --git a/src/test/ui/issues/issue-11692-2.stderr b/src/test/ui/issues/issue-11692-2.stderr
index 5d4467080f1..848415435a7 100644
--- a/src/test/ui/issues/issue-11692-2.stderr
+++ b/src/test/ui/issues/issue-11692-2.stderr
@@ -1,8 +1,16 @@
+error: expected a literal
+  --> $DIR/issue-11692-2.rs:2:13
+   |
+LL |     concat!(test!()); //~ ERROR cannot find macro `test!` in this scope
+   |             ^^^^^^^
+   |
+   = note: only literals (like `"foo"`, `42` and `3.14`) can be passed to `concat!()`
+
 error: cannot find macro `test!` in this scope
   --> $DIR/issue-11692-2.rs:2:13
    |
 LL |     concat!(test!()); //~ ERROR cannot find macro `test!` in this scope
    |             ^^^^
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/issues/issue-32950.rs b/src/test/ui/issues/issue-32950.rs
index dc5b063ada4..27d68a11c1f 100644
--- a/src/test/ui/issues/issue-32950.rs
+++ b/src/test/ui/issues/issue-32950.rs
@@ -3,6 +3,7 @@
 #[derive(Debug)]
 struct Baz<T>(
     concat_idents!(Foo, Bar) //~ ERROR `derive` cannot be used on items with type macros
+                             //~^ ERROR cannot find type `FooBar` in this scope
 );
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-32950.stderr b/src/test/ui/issues/issue-32950.stderr
index e8e3347af2e..13aed4a1756 100644
--- a/src/test/ui/issues/issue-32950.stderr
+++ b/src/test/ui/issues/issue-32950.stderr
@@ -4,5 +4,12 @@ error: `derive` cannot be used on items with type macros
 LL |     concat_idents!(Foo, Bar) //~ ERROR `derive` cannot be used on items with type macros
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error[E0412]: cannot find type `FooBar` in this scope
+  --> $DIR/issue-32950.rs:5:5
+   |
+LL |     concat_idents!(Foo, Bar) //~ ERROR `derive` cannot be used on items with type macros
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
+
+error: aborting due to 2 previous errors
 
+For more information about this error, try `rustc --explain E0412`.
diff --git a/src/test/ui/issues/issue-33571.rs b/src/test/ui/issues/issue-33571.rs
index 5f9c514addb..223bbc3ff5e 100644
--- a/src/test/ui/issues/issue-33571.rs
+++ b/src/test/ui/issues/issue-33571.rs
@@ -2,3 +2,5 @@
          Sync, //~ ERROR this unsafe trait should be implemented explicitly
          Copy)]
 enum Foo {}
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-35677.rs b/src/test/ui/issues/issue-35677.rs
index 46d3f7e4af0..71e2125ffd2 100644
--- a/src/test/ui/issues/issue-35677.rs
+++ b/src/test/ui/issues/issue-35677.rs
@@ -3,3 +3,5 @@ fn intersect_map<K, V>(this: &mut HashMap<K, V>, other: HashMap<K, V>) -> bool {
     this.drain()
     //~^ ERROR no method named
 }
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-35677.stderr b/src/test/ui/issues/issue-35677.stderr
index dca096b93f5..61ddb75b3b5 100644
--- a/src/test/ui/issues/issue-35677.stderr
+++ b/src/test/ui/issues/issue-35677.stderr
@@ -1,7 +1,3 @@
-error[E0601]: `main` function not found in crate `issue_35677`
-   |
-   = note: consider adding a `main` function to `$DIR/issue-35677.rs`
-
 error[E0599]: no method named `drain` found for type `&mut std::collections::HashMap<K, V>` in the current scope
   --> $DIR/issue-35677.rs:3:10
    |
@@ -12,7 +8,6 @@ LL |     this.drain()
            `K : std::cmp::Eq`
            `K : std::hash::Hash`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
-Some errors occurred: E0599, E0601.
-For more information about an error, try `rustc --explain E0599`.
+For more information about this error, try `rustc --explain E0599`.
diff --git a/src/test/ui/issues/issue-36617.rs b/src/test/ui/issues/issue-36617.rs
index 846efac41c8..87092689a28 100644
--- a/src/test/ui/issues/issue-36617.rs
+++ b/src/test/ui/issues/issue-36617.rs
@@ -1 +1,3 @@
 #![derive(Copy)] //~ ERROR `derive` may only be applied to structs, enums and unions
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-43023.rs b/src/test/ui/issues/issue-43023.rs
index 32bd66f5a93..072243d881c 100644
--- a/src/test/ui/issues/issue-43023.rs
+++ b/src/test/ui/issues/issue-43023.rs
@@ -16,3 +16,5 @@ trait Tr2 {
     #[derive(Debug)] //~ ERROR `derive` may only be applied to structs, enums and unions
     type F;
 }
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-46438.rs b/src/test/ui/issues/issue-46438.rs
index a16c4c31d81..d78b958463f 100644
--- a/src/test/ui/issues/issue-46438.rs
+++ b/src/test/ui/issues/issue-46438.rs
@@ -4,7 +4,7 @@ macro_rules! m {
     }
 }
 
-trait Trait {}
+trait Tr {}
 
 m!(Tr);
 
diff --git a/src/test/ui/issues/issue-49074.rs b/src/test/ui/issues/issue-49074.rs
index dbd96e96191..ad66e421c6b 100644
--- a/src/test/ui/issues/issue-49074.rs
+++ b/src/test/ui/issues/issue-49074.rs
@@ -9,5 +9,5 @@ mod foo {
 }
 
 fn main() {
-   bar!();
+   bar!(); //~ ERROR cannot find macro `bar!` in this scope
 }
diff --git a/src/test/ui/issues/issue-49074.stderr b/src/test/ui/issues/issue-49074.stderr
index 8de4d081413..d4648270f2d 100644
--- a/src/test/ui/issues/issue-49074.stderr
+++ b/src/test/ui/issues/issue-49074.stderr
@@ -6,6 +6,14 @@ LL | #[marco_use] // typo
    |
    = help: add #![feature(custom_attribute)] to the crate attributes to enable
 
-error: aborting due to previous error
+error: cannot find macro `bar!` in this scope
+  --> $DIR/issue-49074.rs:12:4
+   |
+LL |    bar!(); //~ ERROR cannot find macro `bar!` in this scope
+   |    ^^^
+   |
+   = help: have you added the `#[macro_use]` on the module/import?
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/issues/issue-51279.rs b/src/test/ui/issues/issue-51279.rs
index caef23043cb..ad5438fbd46 100644
--- a/src/test/ui/issues/issue-51279.rs
+++ b/src/test/ui/issues/issue-51279.rs
@@ -22,3 +22,4 @@ unsafe impl<#[cfg_attr(none, may_dangle)] T> Drop for M<T> {
 
 type Z<#[ignored] 'a, #[cfg(none)] T> = X<'a, T>;
 //~^ ERROR #[cfg] cannot be applied on a generic parameter
+//~| ERROR attribute `ignored` is currently unknown to the compiler
diff --git a/src/test/ui/issues/issue-51279.stderr b/src/test/ui/issues/issue-51279.stderr
index 89786f72e18..1706e98e83b 100644
--- a/src/test/ui/issues/issue-51279.stderr
+++ b/src/test/ui/issues/issue-51279.stderr
@@ -46,5 +46,14 @@ error: #[cfg] cannot be applied on a generic parameter
 LL | type Z<#[ignored] 'a, #[cfg(none)] T> = X<'a, T>;
    |                       ^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error[E0658]: The attribute `ignored` is currently unknown to the compiler and may have meaning added to it in the future (see issue #29642)
+  --> $DIR/issue-51279.rs:23:8
+   |
+LL | type Z<#[ignored] 'a, #[cfg(none)] T> = X<'a, T>;
+   |        ^^^^^^^^^^
+   |
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: aborting due to 9 previous errors
 
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/issues/issue-55796.rs b/src/test/ui/issues/issue-55796.rs
index a172f6a7bfa..efdea5c9b1e 100644
--- a/src/test/ui/issues/issue-55796.rs
+++ b/src/test/ui/issues/issue-55796.rs
@@ -22,3 +22,5 @@ pub trait Graph<'a> {
 //~^ ERROR cannot infer
     }
 }
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-55796.stderr b/src/test/ui/issues/issue-55796.stderr
index f8ca0727efb..c05f8b85d0e 100644
--- a/src/test/ui/issues/issue-55796.stderr
+++ b/src/test/ui/issues/issue-55796.stderr
@@ -1,7 +1,3 @@
-error[E0601]: `main` function not found in crate `issue_55796`
-   |
-   = note: consider adding a `main` function to `$DIR/issue-55796.rs`
-
 error[E0495]: cannot infer an appropriate lifetime due to conflicting requirements
   --> $DIR/issue-55796.rs:16:9
    |
@@ -44,7 +40,6 @@ LL |         Box::new(self.in_edges(u).map(|e| e.target()))
            expected std::boxed::Box<(dyn std::iter::Iterator<Item=<Self as Graph<'a>>::Node> + 'static)>
               found std::boxed::Box<dyn std::iter::Iterator<Item=<Self as Graph<'a>>::Node>>
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-Some errors occurred: E0495, E0601.
-For more information about an error, try `rustc --explain E0495`.
+For more information about this error, try `rustc --explain E0495`.
diff --git a/src/test/ui/issues/issue-6596-2.rs b/src/test/ui/issues/issue-6596-2.rs
index 056a720bc5c..b19700efe5a 100644
--- a/src/test/ui/issues/issue-6596-2.rs
+++ b/src/test/ui/issues/issue-6596-2.rs
@@ -4,10 +4,10 @@ macro_rules! g {
     ($inp:ident) => (
         { $inp $nonexistent }
         //~^ ERROR unknown macro variable `nonexistent`
-        //~| ERROR expected one of
     );
 }
 
 fn main() {
+    let foo = 0;
     g!(foo);
 }
diff --git a/src/test/ui/issues/issue-6596-2.stderr b/src/test/ui/issues/issue-6596-2.stderr
index 99decd177ef..20fbe0fab01 100644
--- a/src/test/ui/issues/issue-6596-2.stderr
+++ b/src/test/ui/issues/issue-6596-2.stderr
@@ -7,14 +7,5 @@ LL |         { $inp $nonexistent }
 LL |     g!(foo);
    |     -------- in this macro invocation
 
-error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found `nonexistent`
-  --> $DIR/issue-6596-2.rs:5:16
-   |
-LL |         { $inp $nonexistent }
-   |                ^^^^^^^^^^^^ expected one of 8 possible tokens here
-...
-LL |     g!(foo);
-   |     -------- in this macro invocation
-
-error: aborting due to 2 previous errors
+error: aborting due to previous error