Implement case statements

boot/parser.yy

@@ -141,7 +141,7 @@ along with GCC; see the file COPYING3.  If not see
 %type <elna::boot::unary_expression *> unary_expression;
 %type <elna::boot::binary_expression *> binary_expression;
 %type <std::vector<elna::boot::expression *>> expressions actual_parameter_list;
-%type <elna::boot::designator_expression *> designator_expression;
+%type <elna::boot::designator_expression *> designator_expression dereference_expression;
 %type <elna::boot::procedure_call*> call_expression;
 %type <elna::boot::while_statement *> while_statement;
 %type <elna::boot::if_statement *> if_statement;
@@ -324,6 +324,10 @@ literal:
         {
             $$ = new boot::literal<std::string>(boot::make_position(@1), $1);
         }
+    | IDENTIFIER
+        {
+            $$ = new boot::variable_expression(boot::make_position(@1), $1);
+        }
 traits_expression:
     TRAIT "(" type_expressions ")"
         {
@@ -332,7 +336,7 @@ traits_expression:
         }
 simple_expression:
     literal { $$ = $1; }
-    | designator_expression { $$ = $1; }
+    | dereference_expression { $$ = $1; }
     | traits_expression { $$ = $1; }
     | cast_expression { $$ = $1; }
     | call_expression { $$ = $1; }
@@ -437,7 +441,7 @@ type_expressions:
             $$.emplace($$.cbegin(), $1);
         }
     | type_expression { $$.push_back($1); }
-designator_expression:
+dereference_expression:
     simple_expression "[" expression "]"
         {
             $$ = new boot::array_access_expression(boot::make_position(@2), $1, $3);
@@ -447,6 +451,8 @@ designator_expression:
         {
             $$ = new boot::dereference_expression(boot::make_position(@1), $1);
         }
+designator_expression:
+    dereference_expression { $$ = $1; }
     | IDENTIFIER
         {
             $$ = new boot::variable_expression(boot::make_position(@1), $1);

boot/symbol.cc

@@ -292,6 +292,16 @@ namespace elna::boot
         return nullptr;
     }
 
+    std::shared_ptr<constant_info> info::is_constant()
+    {
+        return nullptr;
+    }
+
+    std::shared_ptr<variable_info> info::is_variable()
+    {
+        return nullptr;
+    }
+
     type_info::type_info(const type symbol)
         : symbol(symbol)
     {
@@ -317,6 +327,21 @@ namespace elna::boot
     {
     }
 
+    std::shared_ptr<constant_info> constant_info::is_constant()
+    {
+        return std::static_pointer_cast<constant_info>(shared_from_this());
+    }
+
+    variable_info::variable_info(const std::string& name, const type symbol)
+        : name(name), symbol(symbol)
+    {
+    }
+
+    std::shared_ptr<variable_info> variable_info::is_variable()
+    {
+        return std::static_pointer_cast<variable_info>(shared_from_this());;
+    }
+
     std::shared_ptr<symbol_table> builtin_symbol_table()
     {
         auto result = std::make_shared<symbol_table>();

gcc/elna-generic.cc

@@ -138,7 +138,7 @@ namespace elna::gcc
             location_t argument_location = get_location(&argument->position());
             if (VOID_TYPE_P(TREE_VALUE(current_parameter)))
             {
-                error_at(argument_location, "too many arguments, expected %i, got %lu",
+                error_at(argument_location, "Too many arguments, expected %i, got %lu",
                         list_length(TYPE_ARG_TYPES(symbol_type)) - 1, arguments.size());
                 this->current_expression = error_mark_node;
                 break;
@@ -182,7 +182,7 @@ namespace elna::gcc
 
             if (is_void_type(record_fields))
             {
-                error_at(argument_location, "too many arguments, expected %i, got %lu",
+                error_at(argument_location, "Too many arguments, expected %i, got %lu",
                         list_length(TYPE_FIELDS(symbol)), arguments.size());
                 this->current_expression = error_mark_node;
                 break;
@@ -767,6 +767,11 @@ namespace elna::gcc
         location_t definition_location = get_location(&definition->position());
         definition->body().accept(this);
 
+        if (!extract_constant(definition_location))
+        {
+            this->current_expression = NULL_TREE;
+            return;
+        }
         tree definition_tree = build_decl(definition_location, CONST_DECL,
                 get_identifier(definition->identifier.c_str()), TREE_TYPE(this->current_expression));
         auto result = this->symbols->enter(definition->identifier, definition_tree);
@@ -1419,9 +1424,18 @@ namespace elna::gcc
     void generic_visitor::visit(boot::case_statement *statement)
     {
         statement->condition().accept(this);
-
         tree condition_expression = this->current_expression;
-        tree end_label_declaration = create_artificial_label(UNKNOWN_LOCATION);
+        tree unqualified_condition = get_qualified_type(TREE_TYPE(this->current_expression), TYPE_UNQUALIFIED);
+
+        if (!INTEGRAL_TYPE_P(unqualified_condition))
+        {
+            error_at(get_location(&statement->condition().position()),
+                    "Case expressions can only be integral numbers, characters and enumerations, given '%s'",
+                    print_type(unqualified_condition).c_str());
+            this->current_expression = NULL_TREE;
+            return;
+        }
+        tree end_label_declaration = create_artificial_label(get_location(&statement->position()));
         tree switch_statements = alloc_stmt_list();
 
         for (const boot::switch_case& case_block : statement->cases)
@@ -1429,7 +1443,17 @@ namespace elna::gcc
             for (boot::literal_expression *const case_label : case_block.labels)
             {
                 case_label->accept(this);
-                tree case_label_declaration = create_artificial_label(get_location(&case_label->position()));
+                location_t case_location = get_location(&case_label->position());
+
+                if (extract_constant(case_location)
+                        && !is_assignable_from(unqualified_condition, this->current_expression))
+                {
+                    error_at(case_location, "Case type '%s' does not match the expression type '%s'",
+                            print_type(TREE_TYPE(this->current_expression)).c_str(),
+                            print_type(unqualified_condition).c_str());
+                    this->current_expression = error_mark_node;
+                }
+                tree case_label_declaration = create_artificial_label(case_location);
                 tree case_expression = build_case_label(this->current_expression, NULL_TREE, case_label_declaration);
 
                 append_to_statement_list(case_expression, &switch_statements);
@@ -1452,4 +1476,19 @@ namespace elna::gcc
 
         this->current_expression = NULL_TREE;
     }
+
+    bool generic_visitor::extract_constant(location_t expression_location)
+    {
+        if (TREE_CODE(this->current_expression) == CONST_DECL)
+        {
+            this->current_expression = DECL_INITIAL(this->current_expression);
+        }
+        if (TREE_CONSTANT(this->current_expression) == 0)
+        {
+            error_at(expression_location, "Expected a constant expression");
+            this->current_expression = error_mark_node;
+            return false;
+        }
+        return true;
+    }
 }

gcc/elna-tree.cc

@@ -37,14 +37,6 @@ namespace elna::gcc
         return is_integral_type(type) || type == elna_float_type_node;
     }
 
-    bool is_primitive_type(tree type)
-    {
-        gcc_assert(TYPE_P(type));
-        return TREE_CODE(type) == INTEGER_TYPE
-            || type == elna_float_type_node
-            || type == elna_bool_type_node;
-    }
-
     bool is_array_type(tree type)
     {
         gcc_assert(TYPE_P(type));
@@ -59,9 +51,7 @@ namespace elna::gcc
     bool is_castable_type(tree type)
     {
         gcc_assert(TYPE_P(type));
-        auto code = TREE_CODE(type);
+        return INTEGRAL_TYPE_P(type) || POINTER_TYPE_P(type) || TREE_CODE(type) == REAL_TYPE;
-
-        return is_primitive_type(type) || POINTER_TYPE_P(type) || code == ENUMERAL_TYPE;
     }
 
     bool are_compatible_pointers(tree lhs_type, tree rhs)

include/elna/boot/ast.h

@@ -483,7 +483,7 @@ namespace elna::boot
         designator_expression();
     };
 
-    class variable_expression : public designator_expression
+    class variable_expression : public designator_expression, public literal_expression
     {
     public:
         const std::string name;

include/elna/boot/symbol.h

@@ -155,6 +155,7 @@ namespace elna::boot
     class type_info;
     class procedure_info;
     class constant_info;
+    class variable_info;
 
     class info : public std::enable_shared_from_this<info>
     {
@@ -163,6 +164,8 @@ namespace elna::boot
 
         virtual std::shared_ptr<type_info> is_type();
         virtual std::shared_ptr<procedure_info> is_procedure();
+        virtual std::shared_ptr<constant_info> is_constant();
+        virtual std::shared_ptr<variable_info> is_variable();
     };
 
     class type_info : public info
@@ -171,7 +174,6 @@ namespace elna::boot
         const type symbol;
 
         explicit type_info(const type symbol);
-
         std::shared_ptr<type_info> is_type() override;
     };
 
@@ -182,7 +184,6 @@ namespace elna::boot
         const std::vector<std::string> names;
 
         procedure_info(const procedure_type symbol, const std::vector<std::string> names);
-
         std::shared_ptr<procedure_info> is_procedure() override;
     };
 
@@ -195,6 +196,17 @@ namespace elna::boot
         const variant symbol;
 
         explicit constant_info(const variant& symbol);
+        std::shared_ptr<constant_info> is_constant() override;
+    };
+
+    class variable_info : public info
+    {
+    public:
+        const std::string name;
+        const type symbol;
+
+        variable_info(const std::string& name, const type symbol);
+        std::shared_ptr<variable_info> is_variable() override;
     };
 
     /**

include/elna/gcc/elna-generic.h

@@ -70,6 +70,7 @@ namespace elna::gcc
         bool expect_trait_type_only(boot::traits_expression *trait);
         bool expect_trait_for_integral_type(boot::traits_expression *trait);
         void visit_statements(const std::vector<boot::statement *>& statements);
+        bool extract_constant(location_t expression_location);
 
     public:
         generic_visitor(std::shared_ptr<symbol_table> symbol_table,

include/elna/gcc/elna-tree.h

@@ -35,7 +35,6 @@ namespace elna::gcc
 
     bool is_integral_type(tree type);
     bool is_numeric_type(tree type);
-    bool is_primitive_type(tree type);
     bool is_array_type(tree type);
     bool is_void_type(tree type);