Implement the sizeof operator

source/ast.cc

@@ -47,6 +47,11 @@ namespace source
         expression->value().accept(this);
     }
 
+    void empty_visitor::visit(size_of_expression *expression)
+    {
+        expression->body().accept(this);
+    }
+
     void empty_visitor::visit(expression_statement *statement)
     {
         statement->body().accept(this);
@@ -754,6 +759,26 @@ namespace source
         delete m_value;
     }
 
+    size_of_expression::size_of_expression(const struct position position, type_expression *body)
+        : expression(position), m_body(body)
+    {
+    }
+
+    void size_of_expression::accept(parser_visitor *visitor)
+    {
+        visitor->visit(this);
+    }
+
+    type_expression& size_of_expression::body()
+    {
+        return *m_body;
+    }
+
+    size_of_expression::~size_of_expression()
+    {
+        delete m_body;
+    }
+
     expression_statement::expression_statement(const struct position position, expression *body)
         : statement(position), m_body(body)
     {

source/lexer.ll

@@ -112,6 +112,9 @@ cast                    {
 as                      {
                             return yy::parser::make_AS(this->location);
                         }
+sizeof                  {
+                            return yy::parser::make_SIZEOF(this->location);
+                        }
 [A-Za-z_][A-Za-z0-9_]*  {
                             return yy::parser::make_IDENTIFIER(yytext, this->location);
                         }

source/parser.yy

@@ -67,7 +67,7 @@
 %token CONST VAR PROCEDURE ARRAY OF TYPE RECORD POINTER TO UNION
 %token BEGIN_BLOCK END_BLOCK EXTERN
 %token LEFT_PAREN RIGHT_PAREN LEFT_SQUARE RIGHT_SQUARE SEMICOLON DOT COMMA
-%token AND OR NOT CAST AS
+%token AND OR NOT CAST AS SIZEOF
 %token GREATER_EQUAL LESS_EQUAL LESS_THAN GREATER_THAN NOT_EQUAL EQUALS
 %token PLUS MINUS MULTIPLICATION DIVISION REMAINDER
 %token ASSIGNMENT COLON HAT AT
@@ -252,9 +252,13 @@ literal:
 pointer:
     literal { $$ = $1; }
     | designator_expression { $$ = $1; }
+    | SIZEOF LEFT_PAREN type_expression RIGHT_PAREN
+        {
+            $$ = new elna::source::size_of_expression(elna::source::make_position(@1), $3);
+        }
     | cast_expression { $$ = $1; }
     | call_expression { $$ = $1; }
-    | LEFT_PAREN expression RIGHT_PAREN { $$ = std::move($2); }
+    | LEFT_PAREN expression RIGHT_PAREN { $$ = $2; }
 summand:
     factor { $$ = std::move($1); }
     | factor MULTIPLICATION factor