Implement 2015 vs 2018 ? kleene op + test

Author: mark-i-m

src/librustc/lint/mod.rs

@@ -127,7 +127,7 @@ macro_rules! declare_lint {
         };
     );
     ($vis: vis $NAME: ident, $Level: ident, $desc: expr,
-     $lint_edition: expr => $edition_level: ident $(,)?
+     $lint_edition: expr => $edition_level: ident
     ) => (
         $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint {
             name: stringify!($NAME),
@@ -142,7 +142,8 @@ macro_rules! declare_lint {
 /// Declare a static `LintArray` and return it as an expression.
 #[macro_export]
 macro_rules! lint_array {
-    ($( $lint:expr ),* $(,)?) => {{
+    ($( $lint:expr ),* ,) => { lint_array!( $($lint),* ) };
+    ($( $lint:expr ),*) => {{
         vec![$($lint),*]
     }}
 }

src/librustc_lint/builtin.rs

@@ -617,7 +617,7 @@ declare_lint! {
     pub ANONYMOUS_PARAMETERS,
     Allow,
     "detects anonymous parameters",
-    Edition::Edition2018 => Warn,
+    Edition::Edition2018 => Warn
 }
 
 /// Checks for use of anonymous parameters (RFC 1685)
@@ -1706,7 +1706,7 @@ impl LintPass for SoftLints {
             UNIONS_WITH_DROP_FIELDS,
             UNREACHABLE_PUB,
             TYPE_ALIAS_BOUNDS,
-            TRIVIAL_BOUNDS,
+            TRIVIAL_BOUNDS
         )
     }
 }

src/libsyntax/ext/expand.rs

@@ -44,8 +44,10 @@ macro_rules! ast_fragments {
     (
         $($Kind:ident($AstTy:ty) {
             $kind_name:expr;
-            $(one fn $fold_ast:ident; fn $visit_ast:ident;)?
-            $(many fn $fold_ast_elt:ident; fn $visit_ast_elt:ident;)?
+            // FIXME: HACK: this should be `$(one ...)?` and `$(many ...)?` but `?` macro
+            // repetition was removed from 2015 edition in #51587 because of ambiguities.
+            $(one fn $fold_ast:ident; fn $visit_ast:ident;)*
+            $(many fn $fold_ast_elt:ident; fn $visit_ast_elt:ident;)*
             fn $make_ast:ident;
         })*
     ) => {
@@ -100,22 +102,22 @@ macro_rules! ast_fragments {
                     AstFragment::OptExpr(expr) =>
                         AstFragment::OptExpr(expr.and_then(|expr| folder.fold_opt_expr(expr))),
                     $($(AstFragment::$Kind(ast) =>
-                        AstFragment::$Kind(folder.$fold_ast(ast)),)?)*
+                        AstFragment::$Kind(folder.$fold_ast(ast)),)*)*
                     $($(AstFragment::$Kind(ast) =>
                         AstFragment::$Kind(ast.into_iter()
                                               .flat_map(|ast| folder.$fold_ast_elt(ast))
-                                              .collect()),)?)*
+                                              .collect()),)*)*
                 }
             }
 
             pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
                 match *self {
                     AstFragment::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
                     AstFragment::OptExpr(None) => {}
-                    $($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)?)*
+                    $($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)*)*
                     $($(AstFragment::$Kind(ref ast) => for ast_elt in &ast[..] {
                         visitor.$visit_ast_elt(ast_elt);
-                    })?)*
+                    })*)*
                 }
             }
         }
@@ -126,10 +128,10 @@ macro_rules! ast_fragments {
             }
             $($(fn $fold_ast(&mut self, ast: $AstTy) -> $AstTy {
                 self.expand_fragment(AstFragment::$Kind(ast)).$make_ast()
-            })?)*
+            })*)*
             $($(fn $fold_ast_elt(&mut self, ast_elt: <$AstTy as IntoIterator>::Item) -> $AstTy {
                 self.expand_fragment(AstFragment::$Kind(SmallVector::one(ast_elt))).$make_ast()
-            })?)*
+            })*)*
         }
 
         impl<'a> MacResult for ::ext::tt::macro_rules::ParserAnyMacro<'a> {