gccrs: Parse const with no value expression

Const with no value expression may exist either in trait or in disabled
blocks. This means we should be able to parse those correctly.

gcc/rust/ChangeLog:

	* ast/rust-item.h: Add a new constructor for const with no value
	expression.
	* parse/rust-parse-impl.h (Parser::parse_const_item): Allow const with
	no expression value.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

diff --git a/gcc/rust/ast/rust-item.h b/gcc/rust/ast/rust-item.h
index b91e18dc03571413e6ed15ede3a0f97d02dee7f1..eba86dca2fa738f2b3d5c5134211d210ec672a55 100644 (file)
--- a/gcc/rust/ast/rust-item.h
+++ b/gcc/rust/ast/rust-item.h
@@ -2604,6 +2604,13 @@ public:
       const_expr (std::move (const_expr)), locus (locus)
   {}
 
+  ConstantItem (std::string ident, Visibility vis, std::unique_ptr<Type> type,
+               std::vector<Attribute> outer_attrs, location_t locus)
+    : VisItem (std::move (vis), std::move (outer_attrs)),
+      identifier (std::move (ident)), type (std::move (type)),
+      const_expr (nullptr), locus (locus)
+  {}
+
   ConstantItem (ConstantItem const &other)
     : VisItem (other), identifier (other.identifier), locus (other.locus)
   {

diff --git a/gcc/rust/parse/rust-parse-impl.h b/gcc/rust/parse/rust-parse-impl.h
index 7844f7214ad2984c44339e09a614c0ca70f4ff10..4738393fd429fd010627e5c3d94d5f0ca6e98c35 100644 (file)
--- a/gcc/rust/parse/rust-parse-impl.h
+++ b/gcc/rust/parse/rust-parse-impl.h
@@ -4783,6 +4783,16 @@ Parser<ManagedTokenSource>::parse_const_item (AST::Visibility vis,
   // parse constant type (required)
   std::unique_ptr<AST::Type> type = parse_type ();
 
+  // A const with no given expression value
+  if (lexer.peek_token ()->get_id () == SEMICOLON)
+    {
+      lexer.skip_token ();
+      return std::unique_ptr<AST::ConstantItem> (
+       new AST::ConstantItem (std::move (ident), std::move (vis),
+                              std::move (type), std::move (outer_attrs),
+                              locus));
+    }
+
   if (!skip_token (EQUAL))
     {
       skip_after_semicolon ();