fuse extern & associated item parsing up to defaultness

19 files changed, 81 insertions, 115 deletions

diff --git a/src/librustc_parse/parser/item.rs b/src/librustc_parse/parser/item.rs
index 5fcd72090ec..20d6182ddc1 100644
--- a/src/librustc_parse/parser/item.rs
+++ b/src/librustc_parse/parser/item.rs
@@ -13,7 +13,7 @@ use syntax::ast::{AssocItem, AssocItemKind, Item, ItemKind, UseTree, UseTreeKind
 use syntax::ast::{Async, Const, Defaultness, IsAuto, PathSegment, Unsafe};
 use syntax::ast::{BindingMode, Block, FnDecl, FnSig, Mac, MacArgs, MacDelimiter, Param, SelfKind};
 use syntax::ast::{EnumDef, Generics, StructField, TraitRef, Ty, TyKind, Variant, VariantData};
-use syntax::ast::{FnHeader, ForeignItem, ForeignItemKind, Mutability, Visibility, VisibilityKind};
+use syntax::ast::{FnHeader, ForeignItem, Mutability, Visibility, VisibilityKind};
 use syntax::ptr::P;
 use syntax::token;
 use syntax::tokenstream::{DelimSpan, TokenStream, TokenTree};
@@ -333,29 +333,19 @@ impl<'a> Parser<'a> {
         self.token.is_keyword(kw::Async) && self.is_keyword_ahead(1, &[kw::Fn])
     }
 
-    fn missing_assoc_item_kind_err(
-        &self,
-        item_type: &str,
-        prev_span: Span,
-    ) -> DiagnosticBuilder<'a> {
-        let expected_kinds = if item_type == "extern" {
-            "missing `fn`, `type`, or `static`"
-        } else {
-            "missing `fn`, `type`, or `const`"
-        };
-
-        // Given this code `path(`, it seems like this is not
-        // setting the visibility of a macro invocation, but rather
-        // a mistyped method declaration.
-        // Create a diagnostic pointing out that `fn` is missing.
-        //
-        // x |     pub path(&self) {
-        //   |        ^ missing `fn`, `type`, or `const`
-        //     pub  path(
-        //        ^^ `sp` below will point to this
+    /// Given this code `path(`, it seems like this is not
+    /// setting the visibility of a macro invocation,
+    /// but rather a mistyped method declaration.
+    /// Create a diagnostic pointing out that `fn` is missing.
+    ///
+    /// ```
+    /// x |     pub   path(&self) {
+    ///   |         ^ missing `fn`, `type`, `const`, or `static`
+    /// ```
+    fn missing_nested_item_kind_err(&self, prev_span: Span) -> DiagnosticBuilder<'a> {
         let sp = prev_span.between(self.token.span);
-        let mut err = self
-            .struct_span_err(sp, &format!("{} for {}-item declaration", expected_kinds, item_type));
+        let expected_kinds = "missing `fn`, `type`, `const`, or `static`";
+        let mut err = self.struct_span_err(sp, &format!("{} for item declaration", expected_kinds));
         err.span_label(sp, expected_kinds);
         err
     }
@@ -639,7 +629,7 @@ impl<'a> Parser<'a> {
     fn parse_assoc_item(
         &mut self,
         at_end: &mut bool,
-        req_name: fn(&token::Token) -> bool,
+        req_name: ReqName,
     ) -> PResult<'a, P<AssocItem>> {
         let attrs = self.parse_outer_attributes()?;
         let mut unclosed_delims = vec![];
@@ -660,39 +650,47 @@ impl<'a> Parser<'a> {
         &mut self,
         at_end: &mut bool,
         mut attrs: Vec<Attribute>,
-        req_name: fn(&token::Token) -> bool,
+        req_name: ReqName,
     ) -> PResult<'a, AssocItem> {
         let lo = self.token.span;
         let vis = self.parse_visibility(FollowedByType::No)?;
         let defaultness = self.parse_defaultness();
+        let (ident, kind) = self.parse_assoc_item_kind(at_end, &mut attrs, req_name, &vis)?;
+        let span = lo.to(self.prev_span);
+        let id = DUMMY_NODE_ID;
+        Ok(AssocItem { id, span, ident, attrs, vis, defaultness, kind, tokens: None })
+    }
 
-        let (ident, kind) = if self.eat_keyword(kw::Type) {
-            self.parse_assoc_ty()?
+    fn parse_assoc_item_kind(
+        &mut self,
+        at_end: &mut bool,
+        attrs: &mut Vec<Attribute>,
+        req_name: ReqName,
+        vis: &Visibility,
+    ) -> PResult<'a, (Ident, AssocItemKind)> {
+        if self.eat_keyword(kw::Type) {
+            self.parse_assoc_ty()
         } else if self.check_fn_front_matter() {
-            let (ident, sig, generics, body) = self.parse_fn(at_end, &mut attrs, req_name)?;
-            (ident, AssocItemKind::Fn(sig, generics, body))
+            let (ident, sig, generics, body) = self.parse_fn(at_end, attrs, req_name)?;
+            Ok((ident, AssocItemKind::Fn(sig, generics, body)))
         } else if self.is_static_global() {
             self.bump(); // `static`
             let mutbl = self.parse_mutability();
             let (ident, ty, expr) = self.parse_item_const_common(Some(mutbl))?;
-            (ident, AssocItemKind::Static(ty, mutbl, expr))
+            Ok((ident, AssocItemKind::Static(ty, mutbl, expr)))
         } else if self.eat_keyword(kw::Const) {
             let (ident, ty, expr) = self.parse_item_const_common(None)?;
-            (ident, AssocItemKind::Const(ty, expr))
+            Ok((ident, AssocItemKind::Const(ty, expr)))
         } else if self.isnt_macro_invocation() {
-            return Err(self.missing_assoc_item_kind_err("associated", self.prev_span));
+            Err(self.missing_nested_item_kind_err(self.prev_span))
         } else if self.token.is_path_start() {
             let mac = self.parse_item_macro(&vis)?;
             *at_end = true;
-            (Ident::invalid(), AssocItemKind::Macro(mac))
+            Ok((Ident::invalid(), AssocItemKind::Macro(mac)))
         } else {
-            self.recover_attrs_no_item(&attrs)?;
-            self.unexpected()?
-        };
-
-        let span = lo.to(self.prev_span);
-        let id = DUMMY_NODE_ID;
-        Ok(AssocItem { id, span, ident, attrs, vis, defaultness, kind, tokens: None })
+            self.recover_attrs_no_item(attrs)?;
+            self.unexpected()
+        }
     }
 
     /// Parses the following grammar:
@@ -869,46 +867,10 @@ impl<'a> Parser<'a> {
         let mut attrs = self.parse_outer_attributes()?;
         let lo = self.token.span;
         let vis = self.parse_visibility(FollowedByType::No)?;
-
-        let (ident, kind) = if self.eat_keyword(kw::Type) {
-            // FOREIGN TYPE ITEM
-            self.parse_item_foreign_type()?
-        } else if self.check_fn_front_matter() {
-            // FOREIGN FUNCTION ITEM
-            let (ident, sig, generics, body) = self.parse_fn(at_end, &mut attrs, |_| true)?;
-            (ident, ForeignItemKind::Fn(sig, generics, body))
-        } else if self.is_static_global() {
-            // FOREIGN STATIC ITEM
-            self.bump(); // `static`
-            let mutbl = self.parse_mutability();
-            let (ident, ty, expr) = self.parse_item_const_common(Some(mutbl))?;
-            (ident, ForeignItemKind::Static(ty, mutbl, expr))
-        } else if self.eat_keyword(kw::Const) {
-            let (ident, ty, expr) = self.parse_item_const_common(None)?;
-            (ident, ForeignItemKind::Const(ty, expr))
-        } else if self.isnt_macro_invocation() {
-            return Err(self.missing_assoc_item_kind_err("extern", self.prev_span));
-        } else if self.token.is_path_start() {
-            let mac = self.parse_item_macro(&vis)?;
-            *at_end = true;
-            (Ident::invalid(), ForeignItemKind::Macro(mac))
-        } else {
-            self.recover_attrs_no_item(&attrs)?;
-            self.unexpected()?
-        };
+        let (ident, kind) = self.parse_assoc_item_kind(at_end, &mut attrs, |_| true, &vis)?;
         Ok(P(self.mk_item(lo, ident, kind, vis, attrs)))
     }
 
-    /// Parses a type from a foreign module.
-    fn parse_item_foreign_type(&mut self) -> PResult<'a, (Ident, ForeignItemKind)> {
-        let (ident, kind) = self.parse_assoc_ty()?;
-        let kind = match kind {
-            AssocItemKind::TyAlias(g, b, d) => ForeignItemKind::TyAlias(g, b, d),
-            _ => unreachable!(),
-        };
-        Ok((ident, kind))
-    }
-
     fn is_static_global(&mut self) -> bool {
         if self.check_keyword(kw::Static) {
             // Check if this could be a closure.
diff --git a/src/test/ui/did_you_mean/issue-40006.rs b/src/test/ui/did_you_mean/issue-40006.rs
index 60633c6930c..2ed682cea95 100644
--- a/src/test/ui/did_you_mean/issue-40006.rs
+++ b/src/test/ui/did_you_mean/issue-40006.rs
@@ -18,10 +18,10 @@ trait A { //~ ERROR missing
 trait B {
     fn xxx() { ### } //~ ERROR expected
 }
-trait C { //~ ERROR missing `fn`, `type`, or `const` for associated-item declaration
+trait C { //~ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     L = M;
 }
-trait D { //~ ERROR missing `fn`, `type`, or `const` for associated-item declaration
+trait D { //~ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     Z = { 2 + 3 };
 }
 trait E {
diff --git a/src/test/ui/did_you_mean/issue-40006.stderr b/src/test/ui/did_you_mean/issue-40006.stderr
index 072e61f6a3c..119e30a3e0f 100644
--- a/src/test/ui/did_you_mean/issue-40006.stderr
+++ b/src/test/ui/did_you_mean/issue-40006.stderr
@@ -1,26 +1,26 @@
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:1:13
    |
 LL |   impl dyn A {
    |  _____________^
 LL | |     Y
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:7:10
    |
 LL |   trait X {
    |  __________^
 LL | |     X() {}
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:15:10
    |
 LL |   trait A {
    |  __________^
 LL | |     X() {}
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
 error: expected `[`, found `#`
   --> $DIR/issue-40006.rs:19:17
@@ -28,21 +28,21 @@ error: expected `[`, found `#`
 LL |     fn xxx() { ### }
    |                 ^ expected `[`
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:21:10
    |
 LL |   trait C {
    |  __________^
 LL | |     L = M;
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:24:10
    |
 LL |   trait D {
    |  __________^
 LL | |     Z = { 2 + 3 };
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
 error: expected one of `!` or `::`, found `(`
   --> $DIR/issue-40006.rs:28:9
@@ -50,11 +50,11 @@ error: expected one of `!` or `::`, found `(`
 LL |     ::Y ();
    |         ^ expected one of `!` or `::`
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-40006.rs:32:8
    |
 LL |     pub hello_method(&self) {
-   |        ^ missing `fn`, `type`, or `const`
+   |        ^ missing `fn`, `type`, `const`, or `static`
 
 error[E0599]: no method named `hello_method` found for struct `S` in the current scope
   --> $DIR/issue-40006.rs:38:7
diff --git a/src/test/ui/macros/issue-54441.rs b/src/test/ui/macros/issue-54441.rs
index a70163df1cb..5570f081b15 100644
--- a/src/test/ui/macros/issue-54441.rs
+++ b/src/test/ui/macros/issue-54441.rs
@@ -1,5 +1,5 @@
 macro_rules! m {
-    //~^ ERROR missing `fn`, `type`, or `static` for extern-item declaration
+    //~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     () => {
         let
     };
diff --git a/src/test/ui/macros/issue-54441.stderr b/src/test/ui/macros/issue-54441.stderr
index 761e7aec723..5857aacb431 100644
--- a/src/test/ui/macros/issue-54441.stderr
+++ b/src/test/ui/macros/issue-54441.stderr
@@ -1,11 +1,11 @@
-error: missing `fn`, `type`, or `static` for extern-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-54441.rs:1:1
    |
 LL | / macro_rules! m {
 LL | |
 LL | |     () => {
 LL | |         let
-   | |________^ missing `fn`, `type`, or `static`
+   | |________^ missing `fn`, `type`, `const`, or `static`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/default.rs b/src/test/ui/parser/default.rs
index 65ecb1ebbe9..50952eef22f 100644
--- a/src/test/ui/parser/default.rs
+++ b/src/test/ui/parser/default.rs
@@ -20,7 +20,7 @@ impl Foo for u16 {
 
 impl Foo for u32 { //~ ERROR not all trait items implemented, missing: `foo`
     default pub fn foo<T: Default>() -> T { T::default() }
-    //~^ ERROR missing `fn`, `type`, or `const` for associated-item declaration
+    //~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
 }
 
 fn main() {}
diff --git a/src/test/ui/parser/default.stderr b/src/test/ui/parser/default.stderr
index ede9e471518..07b051ece2b 100644
--- a/src/test/ui/parser/default.stderr
+++ b/src/test/ui/parser/default.stderr
@@ -1,8 +1,8 @@
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/default.rs:22:12
    |
 LL |     default pub fn foo<T: Default>() -> T { T::default() }
-   |            ^ missing `fn`, `type`, or `const`
+   |            ^ missing `fn`, `type`, `const`, or `static`
 
 error[E0449]: unnecessary visibility qualifier
   --> $DIR/default.rs:16:5
diff --git a/src/test/ui/parser/duplicate-visibility.rs b/src/test/ui/parser/duplicate-visibility.rs
index 1d271fa64b0..f6e7f7e6abe 100644
--- a/src/test/ui/parser/duplicate-visibility.rs
+++ b/src/test/ui/parser/duplicate-visibility.rs
@@ -2,5 +2,5 @@ fn main() {}
 
 extern {
     pub pub fn foo();
-    //~^ ERROR missing `fn`, `type`, or `static` for extern-item declaration
+    //~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
 }
diff --git a/src/test/ui/parser/duplicate-visibility.stderr b/src/test/ui/parser/duplicate-visibility.stderr
index 36a3a1ed5a0..398ba65c9e1 100644
--- a/src/test/ui/parser/duplicate-visibility.stderr
+++ b/src/test/ui/parser/duplicate-visibility.stderr
@@ -1,8 +1,8 @@
-error: missing `fn`, `type`, or `static` for extern-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/duplicate-visibility.rs:4:8
    |
 LL |     pub pub fn foo();
-   |        ^ missing `fn`, `type`, or `static`
+   |        ^ missing `fn`, `type`, `const`, or `static`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/extern-no-fn.rs b/src/test/ui/parser/extern-no-fn.rs
index c37ddd69ce5..dc47f741073 100644
--- a/src/test/ui/parser/extern-no-fn.rs
+++ b/src/test/ui/parser/extern-no-fn.rs
@@ -1,4 +1,5 @@
-extern { //~ ERROR missing `fn`, `type`, or `static` for extern-item declaration
+extern {
+//~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     f();
 }
 
diff --git a/src/test/ui/parser/extern-no-fn.stderr b/src/test/ui/parser/extern-no-fn.stderr
index d2d5e3c4687..8d55eefc8d0 100644
--- a/src/test/ui/parser/extern-no-fn.stderr
+++ b/src/test/ui/parser/extern-no-fn.stderr
@@ -1,10 +1,11 @@
-error: missing `fn`, `type`, or `static` for extern-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/extern-no-fn.rs:1:9
    |
 LL |   extern {
    |  _________^
+LL | |
 LL | |     f();
-   | |____^ missing `fn`, `type`, or `static`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-19398.rs b/src/test/ui/parser/issue-19398.rs
index 982a6be23ac..014c930ef82 100644
--- a/src/test/ui/parser/issue-19398.rs
+++ b/src/test/ui/parser/issue-19398.rs
@@ -1,5 +1,5 @@
 trait T {
-    //~^ ERROR missing `fn`, `type`, or `const` for associated-item declaration
+    //~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     extern "Rust" unsafe fn foo();
 }
 
diff --git a/src/test/ui/parser/issue-19398.stderr b/src/test/ui/parser/issue-19398.stderr
index 2bd6ac3a4b3..b38b39f9bd9 100644
--- a/src/test/ui/parser/issue-19398.stderr
+++ b/src/test/ui/parser/issue-19398.stderr
@@ -1,11 +1,11 @@
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-19398.rs:1:10
    |
 LL |   trait T {
    |  __________^
 LL | |
 LL | |     extern "Rust" unsafe fn foo();
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-21153.rs b/src/test/ui/parser/issue-21153.rs
index 46cd45f28b4..4fe05e6f041 100644
--- a/src/test/ui/parser/issue-21153.rs
+++ b/src/test/ui/parser/issue-21153.rs
@@ -1,4 +1,5 @@
-trait MyTrait<T>: Iterator { //~ ERROR missing `fn`, `type`, or `const`
+trait MyTrait<T>: Iterator {
+    //~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
     Item = T;
 }
 
diff --git a/src/test/ui/parser/issue-21153.stderr b/src/test/ui/parser/issue-21153.stderr
index 6e20a9ce3c4..e9824bd7290 100644
--- a/src/test/ui/parser/issue-21153.stderr
+++ b/src/test/ui/parser/issue-21153.stderr
@@ -1,10 +1,11 @@
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/issue-21153.rs:1:29
    |
 LL |   trait MyTrait<T>: Iterator {
    |  _____________________________^
+LL | |
 LL | |     Item = T;
-   | |____^ missing `fn`, `type`, or `const`
+   | |____^ missing `fn`, `type`, `const`, or `static`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.rs b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.rs
index 592215030f5..748db8983b5 100644
--- a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.rs
+++ b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.rs
@@ -3,7 +3,7 @@ fn main() {}
 impl T for () { //~ ERROR cannot find trait `T` in this scope
 
 fn foo(&self) {}
-//~^ ERROR missing `fn`, `type`, or `const`
+//~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
 
 trait T {
     fn foo(&self);
diff --git a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.stderr b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.stderr
index 1ec54525105..240be39eace 100644
--- a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.stderr
+++ b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-impl-trait.stderr
@@ -7,7 +7,7 @@ LL | impl T for () {
 LL |
    |                                                    ^
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/missing-close-brace-in-impl-trait.rs:5:17
    |
 LL |   fn foo(&self) {}
@@ -15,7 +15,7 @@ LL |   fn foo(&self) {}
 LL | |
 LL | |
 LL | | trait T {
-   | |_ missing `fn`, `type`, or `const`
+   | |_ missing `fn`, `type`, `const`, or `static`
 
 error[E0405]: cannot find trait `T` in this scope
   --> $DIR/missing-close-brace-in-impl-trait.rs:3:6
diff --git a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.rs b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.rs
index 077e3347194..4e8cc6489bc 100644
--- a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.rs
+++ b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.rs
@@ -3,7 +3,7 @@ trait T {
     fn foo(&self);
 
 pub(crate) struct Bar<T>();
-//~^ ERROR missing `fn`, `type`, or `const`
+//~^ ERROR missing `fn`, `type`, `const`, or `static` for item declaration
 
 impl T for Bar<usize> {
 fn foo(&self) {}
diff --git a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.stderr b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.stderr
index 1bb153c461d..54afad5755b 100644
--- a/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.stderr
+++ b/src/test/ui/parser/mismatched-braces/missing-close-brace-in-trait.stderr
@@ -7,11 +7,11 @@ LL | trait T {
 LL | fn main() {}
    |                                                                 ^
 
-error: missing `fn`, `type`, or `const` for associated-item declaration
+error: missing `fn`, `type`, `const`, or `static` for item declaration
   --> $DIR/missing-close-brace-in-trait.rs:5:11
    |
 LL | pub(crate) struct Bar<T>();
-   |           ^ missing `fn`, `type`, or `const`
+   |           ^ missing `fn`, `type`, `const`, or `static`
 
 error[E0601]: `main` function not found in crate `missing_close_brace_in_trait`
   --> $DIR/missing-close-brace-in-trait.rs:1:1