Add MacroItems and MacroStmts in grammer.ron

crates/ra_mbe/src/lib.rs

@@ -37,9 +37,15 @@ pub enum ExpandError {
     NoMatchingRule,
     UnexpectedToken,
     BindingError(String),
+    ConversionError,
 }
 
-pub use crate::syntax_bridge::{ast_to_token_tree, token_tree_to_ast_item_list, syntax_node_to_token_tree};
+pub use crate::syntax_bridge::{
+    ast_to_token_tree,
+    token_tree_to_ast_item_list,
+    syntax_node_to_token_tree,
+    token_tree_to_macro_items,
+};
 
 /// This struct contains AST for a single `macro_rules` definition. What might
 /// be very confusing is that AST has almost exactly the same shape as
@@ -192,21 +198,21 @@ impl_froms!(TokenTree: Leaf, Subtree);
     pub(crate) fn expand_to_syntax(
         rules: &MacroRules,
         invocation: &str,
-    ) -> ra_syntax::TreeArc<ast::SourceFile> {
+    ) -> ra_syntax::TreeArc<ast::MacroItems> {
         let expanded = expand(rules, invocation);
-        token_tree_to_ast_item_list(&expanded)
+        token_tree_to_macro_items(&expanded)
     }
 
     pub(crate) fn assert_expansion(rules: &MacroRules, invocation: &str, expansion: &str) {
         let expanded = expand(rules, invocation);
         assert_eq!(expanded.to_string(), expansion);
 
-        let tree = token_tree_to_ast_item_list(&expanded);
+        let tree = token_tree_to_macro_items(&expanded);
 
         // Eat all white space by parse it back and forth
         let expansion = ast::SourceFile::parse(expansion);
         let expansion = syntax_node_to_token_tree(expansion.syntax()).unwrap().0;
-        let file = token_tree_to_ast_item_list(&expansion);
+        let file = token_tree_to_macro_items(&expansion);
 
         assert_eq!(tree.syntax().debug_dump().trim(), file.syntax().debug_dump().trim());
     }
@@ -346,11 +352,11 @@ impl_froms!(TokenTree: Leaf, Subtree);
             ",
         );
         let expansion = expand(&rules, "structs!(Foo, Bar)");
-        let tree = token_tree_to_ast_item_list(&expansion);
+        let tree = token_tree_to_macro_items(&expansion);
         assert_eq!(
             tree.syntax().debug_dump().trim(),
             r#"
-SOURCE_FILE@[0; 40)
+MACRO_ITEMS@[0; 40)
   STRUCT_DEF@[0; 20)
     STRUCT_KW@[0; 6) "struct"
     NAME@[6; 9)
@@ -527,7 +533,7 @@ SOURCE_FILE@[0; 40)
 
         assert_eq!(
             expand_to_syntax(&rules, "foo! { 1 + 1  }").syntax().debug_dump().trim(),
-            r#"SOURCE_FILE@[0; 15)
+            r#"MACRO_ITEMS@[0; 15)
   FN_DEF@[0; 15)
     FN_KW@[0; 2) "fn"
     NAME@[2; 5)

crates/ra_mbe/src/syntax_bridge.rs

@@ -30,6 +30,29 @@ pub fn syntax_node_to_token_tree(node: &SyntaxNode) -> Option<(tt::Subtree, Toke
     Some((tt, token_map))
 }
 
+// The following items are what `rustc` macro can be parsed into :
+// link: https://github.com/rust-lang/rust/blob/9ebf47851a357faa4cd97f4b1dc7835f6376e639/src/libsyntax/ext/expand.rs#L141
+// * Expr(P<ast::Expr>)
+// * Pat(P<ast::Pat>)
+// * Ty(P<ast::Ty>)
+// * Stmts(SmallVec<[ast::Stmt; 1]>)
+// * Items(SmallVec<[P<ast::Item>; 1]>)
+//
+// * TraitItems(SmallVec<[ast::TraitItem; 1]>)
+// * ImplItems(SmallVec<[ast::ImplItem; 1]>)
+// * ForeignItems(SmallVec<[ast::ForeignItem; 1]>
+//
+//
+
+/// Parses the token tree (result of macro expansion) as a sequence of items
+pub fn token_tree_to_macro_items(tt: &tt::Subtree) -> TreeArc<ast::MacroItems> {
+    let token_source = SubtreeTokenSource::new(tt);
+    let mut tree_sink = TtTreeSink::new(token_source.querier());
+    ra_parser::parse_macro_items(&token_source, &mut tree_sink);
+    let syntax = tree_sink.inner.finish();
+    ast::MacroItems::cast(&syntax).unwrap().to_owned()
+}
+
 /// Parses the token tree (result of macro expansion) as a sequence of items
 pub fn token_tree_to_ast_item_list(tt: &tt::Subtree) -> TreeArc<ast::SourceFile> {
     let token_source = SubtreeTokenSource::new(tt);