unify/improve/simplify attribute parsing

src/test/ui/did_you_mean/issue-40006.stderr

@@ -32,11 +32,11 @@ LL |     X() {}
 LL | }
    | - the item list ends here
 
-error: expected `[`, found `#`
+error: expected one of `!` or `[`, found `#`
   --> $DIR/issue-40006.rs:19:17
    |
 LL |     fn xxx() { ### }
-   |                 ^ expected `[`
+   |                 ^ expected one of `!` or `[`
 
 error: expected one of `!` or `::`, found `=`
   --> $DIR/issue-40006.rs:22:7

src/test/ui/generic-associated-types/empty_generics.rs

@@ -3,7 +3,7 @@
 
 trait Foo {
     type Bar<,>;
-    //~^ ERROR expected one of `>`, `const`, identifier, or lifetime, found `,`
+    //~^ ERROR expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
 }
 
 fn main() {}

src/test/ui/generic-associated-types/empty_generics.stderr

@@ -1,10 +1,10 @@
-error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
   --> $DIR/empty_generics.rs:5:14
    |
 LL | trait Foo {
    |           - while parsing this item list starting here
 LL |     type Bar<,>;
-   |              ^ expected one of `>`, `const`, identifier, or lifetime
+   |              ^ expected one of `#`, `>`, `const`, identifier, or lifetime
 LL |
 LL | }
    | - the item list ends here

src/test/ui/issues/issue-20616-8.rs

@@ -29,7 +29,7 @@ type Type_5_<'a> = Type_1_<'a, ()>;
 
 
 type Type_8<'a,,> = &'a ();
-//~^ error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+//~^ error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
 
 
 //type Type_9<T,,> = Box<T>; // error: expected identifier, found `,`

src/test/ui/issues/issue-20616-8.stderr

@@ -1,8 +1,8 @@
-error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
   --> $DIR/issue-20616-8.rs:31:16
    |
 LL | type Type_8<'a,,> = &'a ();
-   |                ^ expected one of `>`, `const`, identifier, or lifetime
+   |                ^ expected one of `#`, `>`, `const`, identifier, or lifetime
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-20616-9.rs

@@ -32,4 +32,4 @@ type Type_5_<'a> = Type_1_<'a, ()>;
 
 
 type Type_9<T,,> = Box<T>;
-//~^ error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+//~^ error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`

src/test/ui/issues/issue-20616-9.stderr

@@ -1,8 +1,8 @@
-error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
   --> $DIR/issue-20616-9.rs:34:15
    |
 LL | type Type_9<T,,> = Box<T>;
-   |               ^ expected one of `>`, `const`, identifier, or lifetime
+   |               ^ expected one of `#`, `>`, `const`, identifier, or lifetime
 
 error: aborting due to previous error
 

src/test/ui/parser/bounds-lifetime.rs

@@ -6,6 +6,6 @@ type A = for<'a: 'b + 'c> fn(); // OK (rejected later by ast_validation)
 type A = for<'a: 'b,> fn(); // OK(rejected later by ast_validation)
 type A = for<'a: 'b +> fn(); // OK (rejected later by ast_validation)
 type A = for<'a, T> fn(); // OK (rejected later by ast_validation)
-type A = for<,> fn(); //~ ERROR expected one of `>`, `const`, identifier, or lifetime, found `,`
+type A = for<,> fn(); //~ ERROR expected one of `#`, `>`, `const`, identifier, or lifetime
 
 fn main() {}

src/test/ui/parser/bounds-lifetime.stderr

@@ -1,8 +1,8 @@
-error: expected one of `>`, `const`, identifier, or lifetime, found `,`
+error: expected one of `#`, `>`, `const`, identifier, or lifetime, found `,`
   --> $DIR/bounds-lifetime.rs:9:14
    |
 LL | type A = for<,> fn();
-   |              ^ expected one of `>`, `const`, identifier, or lifetime
+   |              ^ expected one of `#`, `>`, `const`, identifier, or lifetime
 
 error: aborting due to previous error
 

src/test/ui/parser/column-offset-1-based.rs

@@ -1 +1 @@
-# //~ ERROR expected `[`, found `<eof>`
+# //~ ERROR expected one of `!` or `[`, found `<eof>`

src/test/ui/parser/column-offset-1-based.stderr

@@ -1,8 +1,8 @@
-error: expected `[`, found `<eof>`
+error: expected one of `!` or `[`, found `<eof>`
   --> $DIR/column-offset-1-based.rs:1:1
    |
 LL | #
-   | ^ expected `[`
+   | ^ expected one of `!` or `[`
 
 error: aborting due to previous error
 

src/test/ui/parser/doc-comment-in-if-statement.rs

@@ -1,4 +1,5 @@
 fn main() {
     if true /*!*/ {}
     //~^ ERROR expected `{`, found doc comment `/*!*/`
+    //~| ERROR expected outer doc comment
 }

src/test/ui/parser/doc-comment-in-if-statement.stderr

@@ -1,10 +1,19 @@
+error: expected outer doc comment
+  --> $DIR/doc-comment-in-if-statement.rs:2:13
+   |
+LL |     if true /*!*/ {}
+   |             ^^^^^
+   |
+   = note: inner doc comments like this (starting with `//!` or `/*!`) can only appear before items
+
 error: expected `{`, found doc comment `/*!*/`
   --> $DIR/doc-comment-in-if-statement.rs:2:13
    |
 LL |     if true /*!*/ {}
-   |     --      ^^^^^ expected `{`
-   |     |
+   |     --      ^^^^^ -- help: try placing this code inside a block: `{ {} }`
+   |     |       |
+   |     |       expected `{`
    |     this `if` expression has a condition, but no block
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 

src/test/ui/parser/issue-1655.rs

@@ -1,6 +1,5 @@
-// error-pattern:expected `[`, found `vec`
 mod blade_runner {
-    #vec[doc(
+    #vec[doc( //~ ERROR expected one of `!` or `[`, found `vec`
         brief = "Blade Runner is probably the best movie ever",
         desc = "I like that in the world of Blade Runner it is always
                 raining, and that it's always night time. And Aliens

src/test/ui/parser/issue-1655.stderr

@@ -1,8 +1,8 @@
-error: expected `[`, found `vec`
-  --> $DIR/issue-1655.rs:3:6
+error: expected one of `!` or `[`, found `vec`
+  --> $DIR/issue-1655.rs:2:6
    |
 LL |     #vec[doc(
-   |      ^^^ expected `[`
+   |      ^^^ expected one of `!` or `[`
 
 error: aborting due to previous error
 

src/test/ui/parser/issue-63135.rs

@@ -1,3 +1,3 @@
-// error-pattern: aborting due to 7 previous errors
+// error-pattern: aborting due to 5 previous errors
 
 fn i(n{...,f #

src/test/ui/parser/issue-63135.stderr

@@ -31,23 +31,11 @@ LL | fn i(n{...,f #
    |        |  expected `}`
    |        `..` must be at the end and cannot have a trailing comma
 
-error: expected `[`, found `}`
+error: expected one of `!` or `[`, found `}`
   --> $DIR/issue-63135.rs:3:16
    |
 LL | fn i(n{...,f #
-   |                ^ expected `[`
+   |                ^ expected one of `!` or `[`
 
-error: expected one of `:` or `|`, found `)`
-  --> $DIR/issue-63135.rs:3:16
-   |
-LL | fn i(n{...,f #
-   |                ^ expected one of `:` or `|`
-
-error: expected `;` or `{`, found `<eof>`
-  --> $DIR/issue-63135.rs:3:16
-   |
-LL | fn i(n{...,f #
-   |                ^ expected `;` or `{`
-
-error: aborting due to 7 previous errors
+error: aborting due to 5 previous errors