Merge #985

985: Parse macro!(); as MacroInvocation with semicolon r=CohenArthur a=CohenArthur

When parsing a macro invocation as a statement, the parser would parse
an expression and then try parsing a semicolon. Since no actual
lookahead was done (which is a good thing), we couldn't convert a
`MacroInvocation` to a `MacroInvocationSemi` after the fact.

Since, unlike function calls, macro invocations can act differently
based on whether or not they are followed by a semicolon, we actually
need to differentiate between the two up until expansion.

This commits adds a new virtual method for ExprWithoutBlock when
converting to ExprStmtWithoutBlock so that classes inheriting
ExprWithoutBlock can specify a new behavior. In the case of our
MacroInvocation class, it simply means toggling a boolean: If we're
converting a macro from an expression to a statement, it must mean that
it should contain a semicolon.

Closes #941 

Co-authored-by: Arthur Cohen <arthur.cohen@embecosm.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/gcc/rust/ast/rust-stmt.h b/gcc/rust/ast/rust-stmt.h
index 61bce4a..942da7f 100644
--- a/gcc/rust/ast/rust-stmt.h
+++ b/gcc/rust/ast/rust-stmt.h
@@ -211,8 +211,9 @@ public:
   std::string as_string () const override;
 
   ExprStmtWithoutBlock (std::unique_ptr<ExprWithoutBlock> expr, Location locus)
-    : ExprStmt (locus), expr (std::move (expr))
+    : ExprStmt (locus), expr (std::move (expr->to_stmt ()))
   {}
+
   /*ExprStmtWithoutBlock (std::unique_ptr<Expr> expr, Location locus)
     : ExprStmt (locus), expr (std::move (expr))
   {}*/
@@ -336,9 +337,6 @@ protected:
   }
 };
 
-/* Replaced definition of MacroInvocationSemi with forward decl - defined in
- * rust-macro.h */
-class MacroInvocationSemi;
 } // namespace AST
 } // namespace Rust