expand: address review comments

src/librustc_expand/mbe/macro_rules.rs

@@ -180,17 +180,12 @@ impl TTMacroExpander for MacroRulesMacroExpander {
     }
 }
 
-struct MacroRulesDummyExpander;
+fn macro_rules_dummy_expander<'cx>(
-
+    _: &'cx mut ExtCtxt<'_>,
-impl TTMacroExpander for MacroRulesDummyExpander {
+    span: Span,
-    fn expand<'cx>(
+    _: TokenStream,
-        &self,
+) -> Box<dyn MacResult + 'cx> {
-        _: &'cx mut ExtCtxt<'_>,
+    DummyResult::any(span)
-        sp: Span,
-        _: TokenStream,
-    ) -> Box<dyn MacResult + 'cx> {
-        DummyResult::any(sp)
-    }
 }
 
 fn trace_macros_note(cx_expansions: &mut FxHashMap<Span, Vec<String>>, sp: Span, message: String) {
@@ -443,14 +438,14 @@ pub fn compile_declarative_macro(
             let s = parse_failure_msg(&token);
             let sp = token.span.substitute_dummy(def.span);
             sess.span_diagnostic.struct_span_err(sp, &s).span_label(sp, msg).emit();
-            return mk_syn_ext(Box::new(MacroRulesDummyExpander));
+            return mk_syn_ext(Box::new(macro_rules_dummy_expander));
         }
         Error(sp, msg) => {
             sess.span_diagnostic.struct_span_err(sp.substitute_dummy(def.span), &msg).emit();
-            return mk_syn_ext(Box::new(MacroRulesDummyExpander));
+            return mk_syn_ext(Box::new(macro_rules_dummy_expander));
         }
         ErrorReported => {
-            return mk_syn_ext(Box::new(MacroRulesDummyExpander));
+            return mk_syn_ext(Box::new(macro_rules_dummy_expander));
         }
     };
 
@@ -513,16 +508,14 @@ pub fn compile_declarative_macro(
         None => {}
     }
 
-    let expander: Box<_> = Box::new(MacroRulesMacroExpander {
+    mk_syn_ext(Box::new(MacroRulesMacroExpander {
         name: def.ident,
         span: def.span,
         transparency,
         lhses,
         rhses,
         valid,
-    });
+    }))
-
-    mk_syn_ext(expander)
 }
 
 fn check_lhs_nt_follows(

src/test/ui/editions/edition-keywords-2018-2015-parsing.rs

@@ -1,6 +1,8 @@
 // edition:2018
 // aux-build:edition-kw-macro-2015.rs
 
+#![feature(async_closure)]
+
 fn main() {}
 
 #[macro_use]
@@ -19,8 +21,10 @@ pub fn check_async() {
     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
     r#async = consumes_async_raw!(r#async); // OK
 
-    if passes_ident!(async) == 1 {} //~ ERROR async closures are unstable
+    if passes_ident!(async) == 1 {}
     if passes_ident!(r#async) == 1 {} // OK
     module::async(); //~ ERROR expected identifier, found keyword `async`
     module::r#async(); // OK
+
+    let _recovery_witness: () = 0; //~ ERROR mismatched types
 }

src/test/ui/editions/edition-keywords-2018-2015-parsing.stderr

@@ -1,5 +1,5 @@
 error: expected identifier, found keyword `async`
-  --> $DIR/edition-keywords-2018-2015-parsing.rs:14:13
+  --> $DIR/edition-keywords-2018-2015-parsing.rs:16:13
    |
 LL |     let mut async = 1;
    |             ^^^^^ expected identifier, found keyword
@@ -10,7 +10,7 @@ LL |     let mut r#async = 1;
    |             ^^^^^^^
 
 error: expected identifier, found keyword `async`
-  --> $DIR/edition-keywords-2018-2015-parsing.rs:24:13
+  --> $DIR/edition-keywords-2018-2015-parsing.rs:26:13
    |
 LL |     module::async();
    |             ^^^^^ expected identifier, found keyword
@@ -21,13 +21,13 @@ LL |     module::r#async();
    |             ^^^^^^^
 
 error: no rules expected the token `r#async`
-  --> $DIR/edition-keywords-2018-2015-parsing.rs:18:31
+  --> $DIR/edition-keywords-2018-2015-parsing.rs:20:31
    |
 LL |     r#async = consumes_async!(r#async);
    |                               ^^^^^^^ no rules expected this token in macro call
 
 error: no rules expected the token `async`
-  --> $DIR/edition-keywords-2018-2015-parsing.rs:19:35
+  --> $DIR/edition-keywords-2018-2015-parsing.rs:21:35
    |
 LL |     r#async = consumes_async_raw!(async);
    |                                   ^^^^^ no rules expected this token in macro call
@@ -38,20 +38,19 @@ error: macro expansion ends with an incomplete expression: expected one of `move
 LL |     ($i: ident) => ($i)
    |                       ^ expected one of `move`, `|`, or `||`
    | 
-  ::: $DIR/edition-keywords-2018-2015-parsing.rs:22:8
+  ::: $DIR/edition-keywords-2018-2015-parsing.rs:24:8
    |
 LL |     if passes_ident!(async) == 1 {}
    |        -------------------- in this macro invocation
 
-error[E0658]: async closures are unstable
+error[E0308]: mismatched types
-  --> $DIR/edition-keywords-2018-2015-parsing.rs:22:22
+  --> $DIR/edition-keywords-2018-2015-parsing.rs:29:33
    |
-LL |     if passes_ident!(async) == 1 {}
+LL |     let _recovery_witness: () = 0;
-   |                      ^^^^^
+   |                            --   ^ expected `()`, found integer
-   |
+   |                            |
-   = note: see issue #62290 <https://github.com/rust-lang/rust/issues/62290> for more information
+   |                            expected due to this
-   = help: add `#![feature(async_closure)]` to the crate attributes to enable
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/editions/edition-keywords-2018-2018-parsing.rs

@@ -1,6 +1,8 @@
 // edition:2018
 // aux-build:edition-kw-macro-2018.rs
 
+#![feature(async_closure)]
+
 fn main() {}
 
 #[macro_use]
@@ -19,8 +21,10 @@ pub fn check_async() {
     r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
     r#async = consumes_async_raw!(r#async); // OK
 
-    if passes_ident!(async) == 1 {} //~ ERROR async closures are unstable
+    if passes_ident!(async) == 1 {}
     if passes_ident!(r#async) == 1 {} // OK
     module::async(); //~ ERROR expected identifier, found keyword `async`
     module::r#async(); // OK
+
+    let _recovery_witness: () = 0; //~ ERROR mismatched types
 }

src/test/ui/editions/edition-keywords-2018-2018-parsing.stderr

@@ -1,5 +1,5 @@
 error: expected identifier, found keyword `async`
-  --> $DIR/edition-keywords-2018-2018-parsing.rs:14:13
+  --> $DIR/edition-keywords-2018-2018-parsing.rs:16:13
    |
 LL |     let mut async = 1;
    |             ^^^^^ expected identifier, found keyword
@@ -10,7 +10,7 @@ LL |     let mut r#async = 1;
    |             ^^^^^^^
 
 error: expected identifier, found keyword `async`
-  --> $DIR/edition-keywords-2018-2018-parsing.rs:24:13
+  --> $DIR/edition-keywords-2018-2018-parsing.rs:26:13
    |
 LL |     module::async();
    |             ^^^^^ expected identifier, found keyword
@@ -21,13 +21,13 @@ LL |     module::r#async();
    |             ^^^^^^^
 
 error: no rules expected the token `r#async`
-  --> $DIR/edition-keywords-2018-2018-parsing.rs:18:31
+  --> $DIR/edition-keywords-2018-2018-parsing.rs:20:31
    |
 LL |     r#async = consumes_async!(r#async);
    |                               ^^^^^^^ no rules expected this token in macro call
 
 error: no rules expected the token `async`
-  --> $DIR/edition-keywords-2018-2018-parsing.rs:19:35
+  --> $DIR/edition-keywords-2018-2018-parsing.rs:21:35
    |
 LL |     r#async = consumes_async_raw!(async);
    |                                   ^^^^^ no rules expected this token in macro call
@@ -38,20 +38,19 @@ error: macro expansion ends with an incomplete expression: expected one of `move
 LL |     ($i: ident) => ($i)
    |                       ^ expected one of `move`, `|`, or `||`
    | 
-  ::: $DIR/edition-keywords-2018-2018-parsing.rs:22:8
+  ::: $DIR/edition-keywords-2018-2018-parsing.rs:24:8
    |
 LL |     if passes_ident!(async) == 1 {}
    |        -------------------- in this macro invocation
 
-error[E0658]: async closures are unstable
+error[E0308]: mismatched types
-  --> $DIR/edition-keywords-2018-2018-parsing.rs:22:22
+  --> $DIR/edition-keywords-2018-2018-parsing.rs:29:33
    |
-LL |     if passes_ident!(async) == 1 {}
+LL |     let _recovery_witness: () = 0;
-   |                      ^^^^^
+   |                            --   ^ expected `()`, found integer
-   |
+   |                            |
-   = note: see issue #62290 <https://github.com/rust-lang/rust/issues/62290> for more information
+   |                            expected due to this
-   = help: add `#![feature(async_closure)]` to the crate attributes to enable
 
 error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0658`.
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/parser/macro/issue-33569.rs

@@ -1,5 +1,3 @@
-fn main() {}
-
 macro_rules! foo {
     { $+ } => { //~ ERROR expected identifier, found `+`
                 //~^ ERROR missing fragment specifier
@@ -8,3 +6,5 @@ macro_rules! foo {
 }
 
 foo!();
+
+fn main() {}

src/test/ui/parser/macro/issue-33569.stderr

@@ -1,17 +1,17 @@
 error: expected identifier, found `+`
-  --> $DIR/issue-33569.rs:4:8
+  --> $DIR/issue-33569.rs:2:8
    |
 LL |     { $+ } => {
    |        ^
 
 error: expected one of: `*`, `+`, or `?`
-  --> $DIR/issue-33569.rs:6:13
+  --> $DIR/issue-33569.rs:4:13
    |
 LL |         $(x)(y)
    |             ^^^
 
 error: missing fragment specifier
-  --> $DIR/issue-33569.rs:4:8
+  --> $DIR/issue-33569.rs:2:8
    |
 LL |     { $+ } => {
    |        ^

src/test/ui/proc-macro/invalid-punct-ident-4.rs

@@ -1,10 +1,12 @@
 // aux-build:invalid-punct-ident.rs
 
-// We use `main` not found below as a witness for error recovery in proc macro expansion.
+#[macro_use]
-
-#[macro_use] //~ ERROR `main` function not found
 extern crate invalid_punct_ident;
 
 lexer_failure!();
 //~^ ERROR proc macro panicked
 //~| ERROR unexpected closing delimiter: `)`
+
+fn main() {
+    let _recovery_witness: () = 0; //~ ERROR mismatched types
+}

src/test/ui/proc-macro/invalid-punct-ident-4.stderr

@@ -1,5 +1,5 @@
 error: unexpected closing delimiter: `)`
-  --> $DIR/invalid-punct-ident-4.rs:8:1
+  --> $DIR/invalid-punct-ident-4.rs:6:1
    |
 LL | lexer_failure!();
    | ^^^^^^^^^^^^^^^^^ unexpected closing delimiter
@@ -7,20 +7,19 @@ LL | lexer_failure!();
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: proc macro panicked
-  --> $DIR/invalid-punct-ident-4.rs:8:1
+  --> $DIR/invalid-punct-ident-4.rs:6:1
    |
 LL | lexer_failure!();
    | ^^^^^^^^^^^^^^^^^
 
-error[E0601]: `main` function not found in crate `invalid_punct_ident_4`
+error[E0308]: mismatched types
-  --> $DIR/invalid-punct-ident-4.rs:5:1
+  --> $DIR/invalid-punct-ident-4.rs:11:33
    |
-LL | / #[macro_use]
+LL |     let _recovery_witness: () = 0;
-LL | | extern crate invalid_punct_ident;
+   |                            --   ^ expected `()`, found integer
-LL | |
+   |                            |
-LL | | lexer_failure!();
+   |                            expected due to this
-   | |_________________^ consider adding a `main` function to `$DIR/invalid-punct-ident-4.rs`
 
 error: aborting due to 3 previous errors
 
-For more information about this error, try `rustc --explain E0601`.
+For more information about this error, try `rustc --explain E0308`.