[mcs] Initial by ref returns and variables support

[mono.git] / mcs / mcs / cs-parser.jay

diff --git a/mcs/mcs/cs-parser.jay b/mcs/mcs/cs-parser.jay
index 5f885a77763b8ccebc07be47fb643c310be926f5..648effd7f1095c7731e5ed6797a6bd3ceb20dd3e 100644 (file)
--- a/mcs/mcs/cs-parser.jay
+++ b/mcs/mcs/cs-parser.jay
@@ -1161,7 +1161,7 @@ constant_initializer_expr
 field_declaration
        : opt_attributes
          opt_modifiers
-         member_type IDENTIFIER
+         ref_member_type IDENTIFIER
          {
                lexer.parsing_generic_declaration = false;
 
@@ -1364,10 +1364,29 @@ method_declaration
          }
        ;
 
+ref_member_type
+       : member_type
+         {
+               $$ = $1;
+         }
+       | REF
+         {
+               lexer.parsing_generic_declaration = true;
+         }
+         type
+         {
+               if (lang_version < LanguageVersion.V_7) {
+                       FeatureIsNotAvailable (GetLocation ($1), "byref locals and returns");
+               }
+
+               $$ = new ReferenceTypeExpr ((FullNamedExpression) $3, GetLocation ($1));
+         }
+       ;
+
 method_header
        : opt_attributes
          opt_modifiers
-         member_type
+         ref_member_type
          method_declaration_name OPEN_PARENS
          {
                valid_param_mod = ParameterModifierType.All;
@@ -1452,7 +1471,7 @@ method_header
          }
        | opt_attributes
          opt_modifiers
-         member_type
+         ref_member_type
          modifiers method_declaration_name OPEN_PARENS opt_formal_parameter_list CLOSE_PARENS
          {
                MemberName name = (MemberName) $5;
@@ -1473,7 +1492,7 @@ method_header
          }
        | opt_attributes
          opt_modifiers
-         member_type
+         ref_member_type
          method_declaration_name error
          {
                Error_SyntaxError (yyToken);
@@ -1534,7 +1553,7 @@ expression_block
                ++lexer.parsing_block;
                start_block (GetLocation ($1));
         }
-        expression SEMICOLON
+        lambda_arrow_expression SEMICOLON
         {
                lexer.parsing_block = 0;
                current_block.AddStatement (new ContextualReturn ((Expression) $3));
@@ -1838,7 +1857,7 @@ arglist_modifier
 property_declaration
        : opt_attributes
          opt_modifiers
-         member_type
+         ref_member_type
          member_declaration_name
          {
                lexer.parsing_generic_declaration = false;
@@ -1865,6 +1884,16 @@ property_declaration
 
                if (doc_support)
                        current_property.DocComment = ConsumeStoredComment ();
+
+               if ($3 is ReferenceTypeExpr) {
+                       if (current_property.Get == null) {
+                               report.Error (8146, GetLocation ($4), "`{0}': property and indexer which return by reference must have a get accessor", current_property.GetSignatureForError ());
+                       }
+
+                       if (current_property.Set != null) {
+                               report.Error (8147, GetLocation ($4), "`{0}': property and indexer which return by reference cannot have set accessors", current_property.GetSignatureForError ());
+                       }
+               }
          }
          CLOSE_BRACE
          {
@@ -1877,7 +1906,7 @@ property_declaration
          }
        | opt_attributes
          opt_modifiers
-         member_type
+         ref_member_type
          member_declaration_name
          {
                lexer.parsing_generic_declaration = false;
@@ -1939,7 +1968,7 @@ property_initializer
 
 indexer_declaration
        : opt_attributes opt_modifiers
-         member_type indexer_declaration_name OPEN_BRACKET
+         ref_member_type indexer_declaration_name OPEN_BRACKET
          {
                valid_param_mod = ParameterModifierType.Params | ParameterModifierType.DefaultValue;
          }
@@ -1979,6 +2008,16 @@ indexer_declaration
          
                if (doc_support)
                        current_property.DocComment = ConsumeStoredComment ();
+
+               if ($3 is ReferenceTypeExpr) {
+                       if (current_property.Get == null) {
+                               report.Error (8146, GetLocation ($4), "`{0}': property and indexer which return by reference must have a get accessor", current_property.GetSignatureForError ());
+                       }
+
+                       if (current_property.Set != null) {
+                               report.Error (8147, GetLocation ($4), "`{0}': property and indexer which return by reference cannot have set accessors", current_property.GetSignatureForError ());
+                       }
+               }
                        
                current_property = null;                
          }
@@ -2938,7 +2977,7 @@ delegate_declaration
        : opt_attributes
          opt_modifiers
          DELEGATE
-         member_type type_declaration_name
+         ref_member_type type_declaration_name
          OPEN_PARENS
          {
                valid_param_mod = ParameterModifierType.Ref | ParameterModifierType.Out | ParameterModifierType.Params | ParameterModifierType.DefaultValue;
@@ -5109,7 +5148,7 @@ lambda_expression_body
        : {
                start_block (Location.Null);
          }
-         expression    // All expressions must handle error or current block won't be restored and breaking ast completely
+         lambda_arrow_expression       // All expressions must handle error or current block won't be restored and breaking ast completely
          {
                Block b = end_block (Location.Null);
                b.IsCompilerGenerated = true;
@@ -5129,6 +5168,11 @@ lambda_expression_body
          }
        ;
 
+lambda_arrow_expression
+       : expression
+       | reference_expression
+       ;
+
 expression_or_error
        : expression
        | error
@@ -5939,6 +5983,28 @@ block_variable_declaration
                current_variable = null;
                lbag.AddLocation ($$, GetLocation ($1), GetLocation ($7));
          }
+       | REF variable_type identifier_inside_body
+         {
+               if (lang_version < LanguageVersion.V_7) {
+                       FeatureIsNotAvailable (GetLocation ($1), "byref locals and returns");
+               }
+
+               var lt = (LocatedToken) $3;
+               var li = new LocalVariable (current_block, lt.Value, LocalVariable.Flags.ByRef, lt.Location);
+               current_block.AddLocalName (li);
+               current_variable = new BlockVariable ((FullNamedExpression) $2, li);
+         }
+         opt_local_variable_initializer opt_variable_declarators SEMICOLON
+         {
+               $$ = current_variable;
+               current_variable = null;
+               if ($5 != null) {
+                       lbag.AddLocation ($$, PopLocation (), GetLocation ($7));
+               } else {
+                       report.Error (8174, GetLocation ($3), "A declaration of a by-reference variable must have an initializer");
+                       lbag.AddLocation ($$, GetLocation ($7));
+               }
+         }
        ;
 
 opt_local_variable_initializer
@@ -6047,6 +6113,18 @@ block_variable_initializer
                report.Error (1575, GetLocation ($1), "A stackalloc expression requires [] after type");
                $$ = new StackAlloc ((Expression) $2, null, GetLocation ($1));          
          }
+       | reference_expression
+       ;
+
+reference_expression
+       : REF expression
+         {
+               if (lang_version < LanguageVersion.V_7) {
+                       FeatureIsNotAvailable (GetLocation ($1), "byref locals and returns");
+               }
+
+               $$ = new ReferenceExpression ((Expression) $2, GetLocation ($1));
+         }
        ;
 
 expression_statement
@@ -6522,6 +6600,11 @@ return_statement
                $$ = new Return ((Expression) $2, GetLocation ($1));
                lbag.AddStatement ($$, GetLocation ($3));
          }
+       | RETURN reference_expression SEMICOLON
+         {
+               $$ = new Return ((Expression) $2, GetLocation ($1));
+               lbag.AddStatement ($$, GetLocation ($3));
+         }
        | RETURN expression error
          {
                Error_SyntaxError (yyToken);