Recover from some macros

compiler/rustc_parse/src/parser/item.rs

@@ -1343,10 +1343,14 @@ impl<'a> Parser<'a> {
                 let ident = this.parse_field_ident("enum", vlo)?;
 
                 if this.token == token::Not {
-                    return this.unexpected().map_err(|mut err| {
+                    if let Err(mut err) = this.unexpected::<()>() {
-                        err.note(fluent::parse_macro_expands_to_enum_variant);
+                        err.note(fluent::parse_macro_expands_to_enum_variant).emit();
-                        err
+                    }
-                    });
+
+                    this.bump();
+                    this.parse_delim_args()?;
+
+                    return Ok((None, TrailingToken::MaybeComma));
                 }
 
                 let struct_def = if this.check(&token::OpenDelim(Delimiter::Brace)) {
@@ -1586,7 +1590,8 @@ impl<'a> Parser<'a> {
         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
             let lo = this.token.span;
             let vis = this.parse_visibility(FollowedByType::No)?;
-            Ok((this.parse_single_struct_field(adt_ty, lo, vis, attrs)?, TrailingToken::None))
+            this.parse_single_struct_field(adt_ty, lo, vis, attrs)
+                .map(|field| (field, TrailingToken::None))
         })
     }
 
@@ -1698,10 +1703,9 @@ impl<'a> Parser<'a> {
         Ok(a_var)
     }
 
-    fn expect_field_ty_separator(&mut self, adt_ty: &str) -> PResult<'a, ()> {
+    fn expect_field_ty_separator(&mut self) -> PResult<'a, ()> {
         if let Err(mut err) = self.expect(&token::Colon) {
             let sm = self.sess.source_map();
-            let mac_invoc = self.token.kind == token::Not;
             let eq_typo = self.token.kind == token::Eq && self.look_ahead(1, |t| t.is_path_start());
             let semi_typo = self.token.kind == token::Semi
                 && self.look_ahead(1, |t| {
@@ -1713,9 +1717,7 @@ impl<'a> Parser<'a> {
                         _ => true,
                     }
                 });
-            if mac_invoc {
+            if eq_typo || semi_typo {
-                err.subdiagnostic(MacroExpandsToAdtField { adt_ty }).emit();
-            } else if eq_typo || semi_typo {
                 self.bump();
                 // Gracefully handle small typos.
                 err.span_suggestion_short(
@@ -1741,7 +1743,29 @@ impl<'a> Parser<'a> {
         attrs: AttrVec,
     ) -> PResult<'a, FieldDef> {
         let name = self.parse_field_ident(adt_ty, lo)?;
-        self.expect_field_ty_separator(adt_ty)?;
+        // Parse the macro invocation and recover
+        if self.token.kind == token::Not {
+            if let Err(mut err) = self.unexpected::<FieldDef>() {
+                err.subdiagnostic(MacroExpandsToAdtField { adt_ty }).emit();
+                self.bump();
+                self.parse_delim_args()?;
+                return Ok(FieldDef {
+                    span: DUMMY_SP,
+                    ident: None,
+                    vis,
+                    id: DUMMY_NODE_ID,
+                    ty: P(Ty {
+                        id: DUMMY_NODE_ID,
+                        kind: TyKind::Err,
+                        span: DUMMY_SP,
+                        tokens: None,
+                    }),
+                    attrs,
+                    is_placeholder: false,
+                });
+            }
+        }
+        self.expect_field_ty_separator()?;
         let ty = self.parse_ty()?;
         if self.token.kind == token::Colon && self.look_ahead(1, |tok| tok.kind != token::Colon) {
             self.sess.emit_err(errors::SingleColonStructType { span: self.token.span });

compiler/rustc_parse/src/parser/pat.rs

@@ -181,11 +181,7 @@ impl<'a> Parser<'a> {
                 err
             })?;
             if rc == RecoverComma::Yes {
-                self.maybe_recover_unexpected_comma(
+                self.maybe_recover_unexpected_comma(pat.span, false, rt)?;
-                    pat.span,
-                    matches!(pat.kind, PatKind::MacCall(_)),
-                    rt,
-                )?;
             }
             pats.push(pat);
         }

tests/ui/parser/macro/macro-expand-to-field-2.rs

@@ -1,16 +0,0 @@
-#![no_main]
-
-macro_rules! field {
-    ($name:ident:$type:ty) => {
-        $name:$type
-    };
-}
-
-enum EnumVariantField {
-    Named { //~ NOTE while parsing this struct
-        field!(oopsies:()), //~ NOTE macros cannot expand to struct fields
-        //~^ ERROR expected `:`, found `!`
-        //~^^ ERROR expected `,`, or `}`, found `(`
-        //~^^^ NOTE expected `:`
-    },
-}

tests/ui/parser/macro/macro-expand-to-field-2.stderr

@@ -1,18 +0,0 @@
-error: expected `:`, found `!`
-  --> $DIR/macro-expand-to-field-2.rs:11:14
-   |
-LL |         field!(oopsies:()),
-   |              ^ expected `:`
-   |
-   = note: macros cannot expand to struct fields
-
-error: expected `,`, or `}`, found `(`
-  --> $DIR/macro-expand-to-field-2.rs:11:15
-   |
-LL |     Named {
-   |     ----- while parsing this struct
-LL |         field!(oopsies:()),
-   |               ^
-
-error: aborting due to 2 previous errors
-

tests/ui/parser/macro/macro-expand-to-field-3.rs

@@ -1,15 +0,0 @@
-#![no_main]
-
-macro_rules! field {
-    ($name:ident:$type:ty) => {
-        $name:$type
-    };
-}
-
-union EnumVariantField { //~ NOTE while parsing this union
-    A: u32,
-    field!(oopsies:()), //~ NOTE macros cannot expand to union fields
-    //~^ ERROR expected `:`, found `!`
-    //~^^ ERROR expected `,`, or `}`, found `(`
-    //~^^^ NOTE expected `:`
-}

tests/ui/parser/macro/macro-expand-to-field-3.stderr

@@ -1,19 +0,0 @@
-error: expected `:`, found `!`
-  --> $DIR/macro-expand-to-field-3.rs:11:10
-   |
-LL |     field!(oopsies:()),
-   |          ^ expected `:`
-   |
-   = note: macros cannot expand to union fields
-
-error: expected `,`, or `}`, found `(`
-  --> $DIR/macro-expand-to-field-3.rs:11:11
-   |
-LL | union EnumVariantField {
-   |       ---------------- while parsing this union
-LL |     A: u32,
-LL |     field!(oopsies:()),
-   |           ^
-
-error: aborting due to 2 previous errors
-

tests/ui/parser/macro/macro-expand-to-field.rs

@@ -12,15 +12,46 @@ macro_rules! variant {
     }
 }
 
-struct Struct { //~ NOTE while parsing this struct
+struct Struct {
     field!(bar:u128), //~ NOTE macros cannot expand to struct fields
-    //~^ ERROR expected `:`, found `!`
+    //~^ ERROR unexpected token: `!`
-    //~^^ NOTE expected `:`
+    //~^^ NOTE unexpected token after this
-    //~^^^ ERROR expected `,`, or `}`, found `(`
+    a: u32,
-}
+    b: u32,
-
+    field!(recovers:()), //~ NOTE macros cannot expand to struct fields
-enum EnumVariant { //~ NOTE while parsing this enum
-    variant!(whoops), //~ NOTE macros cannot expand to enum variants
     //~^ ERROR unexpected token: `!`
     //~^^ NOTE unexpected token after this
 }
+
+enum EnumVariant {
+    variant!(whoops), //~ NOTE macros cannot expand to enum variants
+    //~^ ERROR unexpected token: `!`
+    //~^^ NOTE unexpected token after this
+    U32,
+    F64,
+    variant!(recovers), //~ NOTE macros cannot expand to enum variants
+    //~^ ERROR unexpected token: `!`
+    //~^^ NOTE unexpected token after this
+}
+
+enum EnumVariantField {
+    Named {
+        field!(oopsies:()), //~ NOTE macros cannot expand to struct fields
+        //~^ ERROR unexpected token: `!`
+        //~^^ unexpected token after this
+        field!(oopsies2:()), //~ NOTE macros cannot expand to struct fields
+        //~^ ERROR unexpected token: `!`
+        //~^^ unexpected token after this
+    },
+}
+
+union Union {
+    A: u32,
+    field!(oopsies:()), //~ NOTE macros cannot expand to union fields
+    //~^ ERROR unexpected token: `!`
+    //~^^ unexpected token after this
+    B: u32,
+    field!(recovers:()), //~ NOTE macros cannot expand to union fields
+    //~^ ERROR unexpected token: `!`
+    //~^^ unexpected token after this
+}

tests/ui/parser/macro/macro-expand-to-field.stderr

@@ -1,29 +1,66 @@
-error: expected `:`, found `!`
+error: unexpected token: `!`
   --> $DIR/macro-expand-to-field.rs:16:10
    |
 LL |     field!(bar:u128),
-   |          ^ expected `:`
+   |          ^ unexpected token after this
    |
    = note: macros cannot expand to struct fields
 
-error: expected `,`, or `}`, found `(`
+error: unexpected token: `!`
-  --> $DIR/macro-expand-to-field.rs:16:11
+  --> $DIR/macro-expand-to-field.rs:21:10
    |
-LL | struct Struct {
+LL |     field!(recovers:()),
-   |        ------ while parsing this struct
+   |          ^ unexpected token after this
-LL |     field!(bar:u128),
+   |
-   |           ^
+   = note: macros cannot expand to struct fields
 
 error: unexpected token: `!`
-  --> $DIR/macro-expand-to-field.rs:23:12
+  --> $DIR/macro-expand-to-field.rs:27:12
    |
-LL | enum EnumVariant {
-   |      ----------- while parsing this enum
 LL |     variant!(whoops),
    |            ^ unexpected token after this
    |
    = note: macros cannot expand to enum variants
-   = help: enum variants can be `Variant`, `Variant = <integer>`, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`
 
-error: aborting due to 3 previous errors
+error: unexpected token: `!`
+  --> $DIR/macro-expand-to-field.rs:32:12
+   |
+LL |     variant!(recovers),
+   |            ^ unexpected token after this
+   |
+   = note: macros cannot expand to enum variants
+
+error: unexpected token: `!`
+  --> $DIR/macro-expand-to-field.rs:39:14
+   |
+LL |         field!(oopsies:()),
+   |              ^ unexpected token after this
+   |
+   = note: macros cannot expand to struct fields
+
+error: unexpected token: `!`
+  --> $DIR/macro-expand-to-field.rs:42:14
+   |
+LL |         field!(oopsies2:()),
+   |              ^ unexpected token after this
+   |
+   = note: macros cannot expand to struct fields
+
+error: unexpected token: `!`
+  --> $DIR/macro-expand-to-field.rs:50:10
+   |
+LL |     field!(oopsies:()),
+   |          ^ unexpected token after this
+   |
+   = note: macros cannot expand to union fields
+
+error: unexpected token: `!`
+  --> $DIR/macro-expand-to-field.rs:54:10
+   |
+LL |     field!(recovers:()),
+   |          ^ unexpected token after this
+   |
+   = note: macros cannot expand to union fields
+
+error: aborting due to 8 previous errors
 

tests/ui/parser/macro/macro-expand-to-match-arm.rs

@@ -10,6 +10,8 @@ fn main() {
         Some(1) => {},
         arm!(None => {}), //~ NOTE macros cannot expand to match arms
         //~^ ERROR unexpected `,` in pattern
+        // doesn't recover
+        Some(2) => {},
         _ => {},
     };
 }