diff --git a/example.elna b/example.elna
index 3d04501..40e6ff2 100644
--- a/example.elna
+++ b/example.elna
@@ -103,6 +103,14 @@ begin
     writei("Test not false")
 end;
 
+proc test_param(d: Int, e: Int);
+begin
+  writei("");
+  writei("Test param");
+  writei(d);
+  writei(e)
+end;
+
 begin
   test_primitive();
   test_string();
@@ -111,5 +119,6 @@ begin
   test_record();
   test_const();
   test_if();
-  test_not()
+  test_not();
+  test_param(8, 7)
 end.
diff --git a/gcc/elna-generic.cc b/gcc/elna-generic.cc
index 0cfbf47..14fecd0 100644
--- a/gcc/elna-generic.cc
+++ b/gcc/elna-generic.cc
@@ -87,10 +87,17 @@ namespace gcc
         }
         else if (symbol)
         {
-            tree fndecl_type = build_function_type_list(integer_type_node, NULL_TREE);
+            tree fndecl_type = build_function_type(void_type_node, TYPE_ARG_TYPES(symbol->payload));
             tree printf_fn = build1(ADDR_EXPR, build_pointer_type(fndecl_type), symbol->payload);
 
-            tree stmt = build_call_nary(integer_type_node, printf_fn, 0);
+            std::vector<tree> arguments(statement->arguments().size());
+            for (std::size_t i = 0; i < statement->arguments().size(); ++i)
+            {
+                statement->arguments().at(i)->accept(this);
+                arguments[i] = this->current_expression;
+            }
+            tree stmt = build_call_array_loc(get_location(&statement->position()),
+                    void_type_node, printf_fn, arguments.size(), arguments.data());
 
             append_to_statement_list(stmt, &this->current_statements);
             this->current_expression = NULL_TREE;
@@ -148,14 +155,14 @@ namespace gcc
 
     void generic_visitor::visit(source::procedure_definition *definition)
     {
-        tree *parameter_types = reinterpret_cast<tree *>(xmalloc(definition->parameters().size() * sizeof(tree)));
+        std::vector<tree> parameter_types(definition->parameters().size());
 
         for (std::size_t i = 0; i < definition->parameters().size(); ++i)
         {
             parameter_types[i] = build_type(definition->parameters().at(i)->type());
         }
         tree declaration_type = build_function_type_array(void_type_node,
-                definition->parameters().size(), parameter_types);
+                definition->parameters().size(), parameter_types.data());
         this->main_fndecl = build_fn_decl(definition->identifier().c_str(), declaration_type);
 
         this->symbol_map->enter(definition->identifier(), source::make_info(this->main_fndecl));
@@ -166,6 +173,21 @@ namespace gcc
         DECL_RESULT(this->main_fndecl) = resdecl;
 
         enter_scope();
+
+        gcc::tree_chain argument_chain;
+        for (std::size_t i = 0; i < definition->parameters().size(); ++i)
+        {
+            auto parameter = definition->parameters().at(i);
+
+            tree declaration_tree = build_decl(get_location(&parameter->position()), PARM_DECL,
+                get_identifier(parameter->identifier().c_str()), parameter_types[i]);
+            DECL_CONTEXT(declaration_tree) = this->main_fndecl;
+            DECL_ARG_TYPE(declaration_tree) = parameter_types[i];
+
+            this->symbol_map->enter(parameter->identifier(), source::make_info(declaration_tree));
+            argument_chain.append(declaration_tree);
+        }
+        DECL_ARGUMENTS(this->main_fndecl) = argument_chain.head();
         definition->body().accept(this);
 
         tree_symbol_mapping mapping = leave_scope();
@@ -180,8 +202,6 @@ namespace gcc
         gimplify_function_tree(this->main_fndecl);
 
         cgraph_node::finalize_function(this->main_fndecl, true);
-
-        free(parameter_types);
     }
 
     void generic_visitor::enter_scope()
diff --git a/include/elna/source/semantic.h b/include/elna/source/semantic.h
new file mode 100644
index 0000000..0c1e223
--- /dev/null
+++ b/include/elna/source/semantic.h
@@ -0,0 +1,100 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#pragma once
+
+#include <list>
+#include "elna/source/ast.h"
+#include "elna/source/symbol_table.h"
+
+namespace elna
+{
+namespace source
+{
+    class name_analysis_visitor final : public empty_visitor
+    {
+        std::shared_ptr<symbol_table> table;
+        const char *filename;
+        std::list<std::unique_ptr<error>> m_errors;
+        const std::size_t pointer_size;
+
+        std::shared_ptr<const type> convert_declaration_type(const type_expression& ast_type) const;
+
+    public:
+        /**
+         * \param table Symbol table.
+         * \param path Source filename.
+         * \param target_pointer_size Pointer size on the target platform.
+         */
+        name_analysis_visitor(std::shared_ptr<symbol_table> table, const char *filename,
+                const std::size_t target_pointer_size);
+
+        /**
+         * \return Collected errors.
+         */
+        const std::list<std::unique_ptr<error>>& errors() const noexcept;
+
+        void visit(constant_definition *definition) override;
+        void visit(declaration *declaration) override;
+        void visit(program *program) override;
+        void visit(procedure_definition *procedure) override;
+    };
+
+    /**
+     * Visitor which allocates registers and stack space for variables and
+     * parameters.
+     */
+    class allocator_visitor final : public empty_visitor
+    {
+        std::ptrdiff_t local_offset;
+        std::ptrdiff_t argument_offset;
+        std::shared_ptr<symbol_table> table;
+
+    public:
+        allocator_visitor(std::shared_ptr<symbol_table> table);
+
+        void visit(declaration *declaration) override;
+        void visit(program *program) override;
+        void visit(procedure_definition *procedure) override;
+        void visit(call_statement *statement) override;
+    };
+
+    /**
+     * This visitor performs the type checking.
+     */
+    class type_analysis_visitor final : public empty_visitor
+    {
+        std::shared_ptr<symbol_table> table;
+        const char *filename;
+        const std::size_t pointer_size;
+        std::list<std::unique_ptr<error>> m_errors;
+
+    public:
+        /**
+         * \param table Symbol table.
+         * \param path Source filename.
+         * \param target_pointer_size Pointer size on the target platform.
+         */
+        type_analysis_visitor(std::shared_ptr<symbol_table> table, const char *filename,
+                const std::size_t target_pointer_size);
+
+        /**
+         * \return Collected errors.
+         */
+        const std::list<std::unique_ptr<error>>& errors() const noexcept;
+
+        void visit(program *program) override;
+        void visit(procedure_definition *procedure) override;
+        void visit(integer_literal *literal) override;
+        void visit(boolean_literal *literal) override;
+        void visit(variable_expression *expression) override;
+        void visit(unary_expression *expression) override;
+        void visit(binary_expression *expression) override;
+        void visit(call_statement *statement) override;
+        void visit(constant_definition *definition) override;
+        void visit(while_statement *statement) override;
+        void visit(if_statement *statement) override;
+        void visit(assign_statement *statement) override;
+    };
+}
+}
diff --git a/include/elna/source/symbol_table.h b/include/elna/source/symbol_table.h
new file mode 100644
index 0000000..b240781
--- /dev/null
+++ b/include/elna/source/symbol_table.h
@@ -0,0 +1,198 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#pragma once
+
+#include <cstdint>
+#include <unordered_map>
+#include <string>
+#include <memory>
+
+namespace elna
+{
+namespace source
+{
+    class symbol_table;
+    class type_info;
+    class typed_info;
+    class constant_info;
+    class variable_info;
+    class parameter_info;
+    class intrinsic_info;
+    class procedure_info;
+
+    /**
+     * Generic language entity information.
+     */
+    class info
+    {
+    public:
+        virtual ~info() = 0;
+
+        virtual type_info *is_type_info() noexcept;
+        virtual typed_info *is_typed_info() noexcept;
+        virtual constant_info *is_constant_info() noexcept;
+        virtual variable_info *is_variable_info() noexcept;
+        virtual parameter_info *is_parameter_info() noexcept;
+        virtual intrinsic_info *is_intrinsic_info() noexcept;
+        virtual procedure_info *is_procedure_info() noexcept;
+
+    protected:
+        info();
+    };
+
+    /**
+     * Type information.
+     */
+    class type_info final : public info
+    {
+        std::shared_ptr<const class type> m_type;
+
+    public:
+        explicit type_info(std::shared_ptr<class type> type);
+        ~type_info() override;
+
+        virtual type_info *is_type_info() noexcept override;
+        std::shared_ptr<const class type> type() const noexcept;
+    };
+
+    /**
+     * Information for a typed symbol.
+     */
+    class typed_info : public info
+    {
+        std::shared_ptr<const class type> m_type;
+
+    protected:
+        typed_info(std::shared_ptr<const class type> type);
+
+    public:
+        ~typed_info() override;
+
+        virtual typed_info *is_typed_info() noexcept override;
+        std::shared_ptr<const class type> type() const noexcept;
+    };
+
+    /**
+     * Constant information.
+     */
+    class constant_info final : public typed_info
+    {
+        std::int32_t m_value;
+
+    public:
+        constant_info(std::shared_ptr<const class type> type, const std::int32_t value);
+
+        virtual constant_info *is_constant_info() noexcept override;
+        std::int32_t value() const noexcept;
+    };
+
+    /**
+     * Variable information.
+     */
+    class variable_info final : public typed_info
+    {
+    public:
+        std::ptrdiff_t offset{ 0 };
+
+        explicit variable_info(std::shared_ptr<const class type> type);
+
+        virtual variable_info *is_variable_info() noexcept override;
+    };
+
+    /**
+     * Procedure parameter information.
+     */
+    class parameter_info final : public typed_info
+    {
+    public:
+        std::ptrdiff_t offset{ 0 };
+
+        explicit parameter_info(std::shared_ptr<const class type> type);
+
+        virtual parameter_info *is_parameter_info() noexcept override;
+    };
+
+    /**
+     * Intrinsic and external procedure information.
+     */
+    class intrinsic_info : public info
+    {
+        std::shared_ptr<const class procedure_type> m_type;
+
+    public:
+        explicit intrinsic_info(const class procedure_type& type);
+        ~intrinsic_info() override;
+
+        std::shared_ptr<const class procedure_type> type() const noexcept;
+        std::size_t parameter_stack_size() const noexcept;
+        virtual intrinsic_info *is_intrinsic_info() noexcept override;
+    };
+
+    /**
+     * Procedure information.
+     */
+    class procedure_info final : public intrinsic_info
+    {
+        std::shared_ptr<symbol_table> local_table;
+
+    public:
+        std::size_t local_stack_size{ 0 };
+        std::size_t argument_stack_size{ 0 };
+
+        procedure_info(const class procedure_type& type, std::shared_ptr<symbol_table> outer_scope);
+        ~procedure_info() override;
+
+        std::shared_ptr<symbol_table> scope();
+        std::size_t stack_size() const noexcept;
+        virtual procedure_info *is_procedure_info() noexcept override;
+    };
+
+    /**
+     * Symbol table.
+     */
+    class symbol_table
+    {
+        std::unordered_map<std::string, std::shared_ptr<info>> entries;
+        std::shared_ptr<symbol_table> outer_scope;
+
+    public:
+        /**
+         * Constructs a new symbol with an optional outer scope.
+         *
+         * \param scope Outer scope.
+         */
+        explicit symbol_table(std::shared_ptr<symbol_table> scope = nullptr);
+
+        /**
+         * Looks for symbol in the table by name. Returns nullptr if the symbol
+         * can not be found.
+         *
+         * \param name Symbol name.
+         * \return Symbol from the table if found.
+         */
+        std::shared_ptr<info> lookup(const std::string& name);
+
+        /**
+         * Registers new symbol.
+         *
+         * \param name Symbol name.
+         * \param entry Symbol information.
+         */
+        void enter(const std::string& name, std::shared_ptr<info> entry);
+
+        /**
+         * Returns the outer scope or nullptr if the this is the global scope.
+         *
+         * \return Outer scope.
+         */
+        std::shared_ptr<symbol_table> scope();
+    };
+
+    /**
+     * Creates a symbol table with predefined symbols.
+     *
+     * \return A symbol table with predefined symbols.
+     */
+    std::shared_ptr<source::symbol_table> add_builtin_symbols();}
+}
diff --git a/source/semantic.cc b/source/semantic.cc
new file mode 100644
index 0000000..1086ba4
--- /dev/null
+++ b/source/semantic.cc
@@ -0,0 +1,325 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "elna/source/semantic.h"
+#include "elna/source/result.h"
+#include <cstdlib>
+
+namespace elna
+{
+namespace source
+{
+    name_analysis_visitor::name_analysis_visitor(std::shared_ptr<symbol_table> table,
+            const char *filename, const std::size_t target_pointer_size)
+        : table(table), filename(filename), pointer_size(target_pointer_size)
+    {
+    }
+
+    void name_analysis_visitor::visit(constant_definition *definition)
+    {
+        auto constant_type = std::make_shared<const class primitive_type>(int_type);
+        this->table->enter(definition->identifier(),
+                std::make_shared<constant_info>(constant_type, definition->body().number()));
+    }
+
+    std::shared_ptr<const type> name_analysis_visitor::convert_declaration_type(const type_expression& ast_type) const
+    {
+        auto variable_type = table->lookup(ast_type.base())->is_type_info()->type();
+        std::shared_ptr<type> declaration_type;
+
+        if (ast_type.is_pointer())
+        {
+            return std::make_shared<pointer_type>(variable_type, 4);
+        }
+        else
+        {
+            return variable_type;
+        }
+    }
+
+    void name_analysis_visitor::visit(declaration *declarationx)
+    {
+        std::shared_ptr<const type> declaration_type = convert_declaration_type(declarationx->type());
+
+        this->table->enter(declarationx->identifier(),
+                std::make_shared<variable_info>(declaration_type));
+    }
+
+    void name_analysis_visitor::visit(program *program)
+    {
+        class procedure_type main_type{ std::vector<std::shared_ptr<const class type>>(), this->pointer_size };
+        this->table->enter("_start", std::make_shared<procedure_info>(main_type, this->table));
+        empty_visitor::visit(program);
+    }
+
+    void name_analysis_visitor::visit(procedure_definition *procedure)
+    {
+        std::vector<std::shared_ptr<const type>> arguments;
+
+        for (auto& parameter : procedure->parameters())
+        {
+            auto declaration_type = convert_declaration_type(parameter->type());
+            arguments.push_back(declaration_type);
+        }
+        procedure_type definition_type{ std::move(arguments), this->pointer_size };
+        auto info = std::make_shared<procedure_info>(definition_type, this->table);
+
+        this->table->enter(procedure->identifier(), info);
+        this->table = info->scope();
+
+        for (std::size_t i = 0; i < procedure->parameters().size(); ++i)
+        {
+            this->table->enter(procedure->parameters().at(i)->identifier(),
+                    std::make_shared<parameter_info>(definition_type.arguments.at(i)));
+        }
+        procedure->body().accept(this);
+
+        this->table = info->scope()->scope();
+    }
+
+    const std::list<std::unique_ptr<error>>& name_analysis_visitor::errors() const noexcept
+    {
+        return m_errors;
+    }
+
+    allocator_visitor::allocator_visitor(std::shared_ptr<symbol_table> table)
+        : table(table)
+    {
+    }
+
+    void allocator_visitor::visit(declaration *declaration)
+    {
+        auto declaration_info = this->table->lookup(declaration->identifier());
+
+        if (auto variable = declaration_info->is_variable_info())
+        {
+            this->local_offset -= sizeof(std::int32_t);
+            variable->offset = this->local_offset;
+        }
+        else if (auto parameter = declaration_info->is_parameter_info())
+        {
+            parameter->offset = this->argument_offset;
+            this->argument_offset += sizeof(std::int32_t);
+        }
+    }
+
+    void allocator_visitor::visit(program *program)
+    {
+        this->local_offset = 0;
+        this->argument_offset = 0;
+
+        empty_visitor::visit(program);
+        table->lookup("_start")->is_procedure_info()->local_stack_size =
+            std::abs(this->local_offset);
+    }
+
+    void allocator_visitor::visit(procedure_definition *procedure)
+    {
+        this->local_offset = 0;
+        this->argument_offset = 0;
+        auto info = this->table->lookup(procedure->identifier())->is_procedure_info();
+        this->table = info->scope();
+
+        empty_visitor::visit(procedure);
+
+        this->table = info->scope()->scope();
+        info->local_stack_size = std::abs(this->local_offset);
+        info->argument_stack_size = this->argument_offset;
+    }
+
+    void allocator_visitor::visit(call_statement *statement)
+    {
+        auto call_info = this->table->lookup(statement->name())->is_intrinsic_info();
+
+        this->argument_offset = std::max(static_cast<std::size_t>(this->argument_offset),
+                call_info->parameter_stack_size());
+    }
+
+    type_analysis_visitor::type_analysis_visitor(std::shared_ptr<symbol_table> table,
+            const char *filename, const std::size_t target_pointer_size)
+        : table(table), filename(filename), pointer_size(target_pointer_size)
+    {
+    }
+
+    void type_analysis_visitor::visit(program *program)
+    {
+        for (auto& definition : program->definitions())
+        {
+            definition->accept(this);
+        }
+        program->body().accept(this);
+    }
+
+    void type_analysis_visitor::visit(procedure_definition *procedure)
+    {
+        auto info = this->table->lookup(procedure->identifier())->is_procedure_info();
+        this->table = info->scope();
+
+        procedure->body().accept(this);
+
+        this->table = info->scope()->scope();
+    }
+
+    void type_analysis_visitor::visit(integer_literal *literal)
+    {
+        literal->data_type = table->lookup("Int")->is_type_info()->type();
+    }
+
+    void type_analysis_visitor::visit(boolean_literal *literal)
+    {
+        literal->data_type = table->lookup("Boolean")->is_type_info()->type();
+    }
+
+    void type_analysis_visitor::visit(variable_expression *expression)
+    {
+        expression->data_type = table->lookup(expression->name())->is_typed_info()->type();
+    }
+
+    void type_analysis_visitor::visit(unary_expression *expression)
+    {
+        empty_visitor::visit(expression);
+
+        switch (expression->operation())
+        {
+            case unary_operator::reference:
+                expression->data_type = std::make_shared<const pointer_type>(expression->operand().data_type,
+                        this->pointer_size);
+                break;
+            case unary_operator::dereference:
+                auto operand_type = expression->operand().data_type;
+
+                if (operand_type->is_pointer_type() != nullptr)
+                {
+                    expression->data_type = operand_type;
+                }
+                else if (operand_type != nullptr)
+                {
+                    auto new_error = std::make_unique<type_mismatch>(operand_type,
+                            type_mismatch::operation::dereference, this->filename, expression->position());
+                    m_errors.push_back(std::move(new_error));
+                }
+                break;
+        }
+    }
+
+    void type_analysis_visitor::visit(binary_expression *expression)
+    {
+        empty_visitor::visit(expression);
+
+        switch (expression->operation())
+        {
+            case binary_operator::sum:
+            case binary_operator::subtraction:
+            case binary_operator::multiplication:
+            case binary_operator::division:
+            case binary_operator::less:
+            case binary_operator::greater:
+            case binary_operator::less_equal:
+            case binary_operator::greater_equal:
+                if (expression->lhs().data_type != nullptr && expression->rhs().data_type != nullptr)
+                {
+                    std::unique_ptr<type_mismatch> new_error;
+
+                    if (*expression->lhs().data_type != int_type)
+                    {
+                        new_error = std::make_unique<type_mismatch>(expression->lhs().data_type,
+                                type_mismatch::operation::arithmetic, this->filename, expression->lhs().position());
+                    }
+                    if (*expression->rhs().data_type != int_type)
+                    {
+                        new_error = std::make_unique<type_mismatch>(expression->rhs().data_type,
+                                type_mismatch::operation::arithmetic, this->filename, expression->rhs().position());
+                    }
+                    if (new_error != nullptr)
+                    {
+                        m_errors.push_back(std::move(new_error));
+                    }
+                }
+            break;
+            case binary_operator::equals:
+            case binary_operator::not_equals:
+                if (expression->lhs().data_type != nullptr && expression->rhs().data_type != nullptr)
+                {
+                    if (expression->lhs().data_type != expression->rhs().data_type)
+                    {
+                        auto new_error = std::make_unique<type_mismatch>(expression->rhs().data_type,
+                                type_mismatch::operation::comparison, this->filename, expression->rhs().position());
+                    }
+                }
+            break;
+        }
+    }
+
+    void type_analysis_visitor::visit(call_statement *statement)
+    {
+        auto call_info = this->table->lookup(statement->name())->is_intrinsic_info();
+
+        std::size_t i{ 0 };
+        for (const auto& argument : statement->arguments())
+        {
+            argument->accept(this);
+
+            if (argument->data_type != nullptr && i < call_info->type()->arguments.size()
+                    && call_info->type()->arguments[i] != argument->data_type)
+            {
+                auto new_error = std::make_unique<type_mismatch>(argument->data_type,
+                        type_mismatch::operation::argument, this->filename, argument->position());
+                m_errors.push_back(std::move(new_error));
+            }
+
+            ++i;
+        }
+    }
+
+    void type_analysis_visitor::visit(constant_definition *definition)
+    {
+        definition->body().accept(this);
+    }
+
+    void type_analysis_visitor::visit(while_statement *statement)
+    {
+        statement->prerequisite().accept(this);
+        auto condition_type = statement->prerequisite().data_type;
+
+        if (condition_type != nullptr && *condition_type != boolean_type)
+        {
+            auto new_error = std::make_unique<type_mismatch>(condition_type,
+                    type_mismatch::operation::condition, this->filename, statement->prerequisite().position());
+            m_errors.push_back(std::move(new_error));
+        }
+        statement->body().accept(this);
+    }
+
+    void type_analysis_visitor::visit(if_statement *statement)
+    {
+        statement->prerequisite().accept(this);
+        auto condition_type = statement->prerequisite().data_type;
+
+        if (condition_type != nullptr && *condition_type != boolean_type)
+        {
+            auto new_error = std::make_unique<type_mismatch>(condition_type,
+                    type_mismatch::operation::condition, this->filename, statement->prerequisite().position());
+            m_errors.push_back(std::move(new_error));
+        }
+        statement->body().accept(this);
+    }
+
+    void type_analysis_visitor::visit(assign_statement *statement)
+    {
+        statement->rvalue().accept(this);
+        auto lvalue_info = this->table->lookup(statement->lvalue())->is_typed_info();
+
+        if (statement->rvalue().data_type != nullptr && lvalue_info->type() == statement->rvalue().data_type)
+        {
+            auto new_error = std::make_unique<type_mismatch>(statement->rvalue().data_type,
+                    type_mismatch::operation::assignment, this->filename, statement->position());
+            m_errors.push_back(std::move(new_error));
+        }
+    }
+
+    const std::list<std::unique_ptr<error>>& type_analysis_visitor::errors() const noexcept
+    {
+        return m_errors;
+    }
+}
+}
diff --git a/source/symbol_table.cc b/source/symbol_table.cc
new file mode 100644
index 0000000..327781d
--- /dev/null
+++ b/source/symbol_table.cc
@@ -0,0 +1,233 @@
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "elna/source/types.h"
+#include "elna/source/symbol_table.h"
+
+namespace elna
+{
+namespace source
+{
+    symbol_table::symbol_table(std::shared_ptr<symbol_table> scope)
+        : outer_scope(scope)
+    {
+    }
+
+    std::shared_ptr<info> symbol_table::lookup(const std::string& name)
+    {
+        auto entry = entries.find(name);
+
+        if (entry != entries.cend())
+        {
+            return entry->second;
+        }
+        if (this->outer_scope != nullptr)
+        {
+            return this->outer_scope->lookup(name);
+        }
+        return nullptr;
+    }
+
+    void symbol_table::enter(const std::string& name, std::shared_ptr<info> entry)
+    {
+        entries.insert({ name, entry });
+    }
+
+    std::shared_ptr<symbol_table> symbol_table::scope()
+    {
+        return this->outer_scope;
+    }
+
+    info::~info()
+    {
+    }
+
+    type_info *info::is_type_info() noexcept
+    {
+        return nullptr;
+    }
+
+    typed_info *info::is_typed_info() noexcept
+    {
+        return nullptr;
+    }
+
+    constant_info *info::is_constant_info() noexcept
+    {
+        return nullptr;
+    }
+
+    variable_info *info::is_variable_info() noexcept
+    {
+        return nullptr;
+    }
+
+    parameter_info *info::is_parameter_info() noexcept
+    {
+        return nullptr;
+    }
+
+    intrinsic_info *info::is_intrinsic_info() noexcept
+    {
+        return nullptr;
+    }
+
+    procedure_info *info::is_procedure_info() noexcept
+    {
+        return nullptr;
+    }
+
+    info::info()
+    {
+    }
+
+    type_info::type_info(std::shared_ptr<class type> type)
+        : info(), m_type(type)
+    {
+    }
+
+    type_info::~type_info()
+    {
+    }
+
+    std::shared_ptr<const class type> type_info::type() const noexcept
+    {
+        return m_type;
+    }
+
+    type_info *type_info::is_type_info() noexcept
+    {
+        return this;
+    }
+
+    typed_info::typed_info(std::shared_ptr<const class type> type)
+        : m_type(type)
+    {
+    }
+
+    typed_info::~typed_info()
+    {
+    }
+
+    typed_info *typed_info::is_typed_info() noexcept
+    {
+        return this;
+    }
+
+    std::shared_ptr<const class type> typed_info::type() const noexcept
+    {
+        return m_type;
+    }
+
+    constant_info::constant_info(const std::shared_ptr<const class type> type, const std::int32_t value)
+        : typed_info(type), m_value(value)
+    {
+    }
+
+    constant_info *constant_info::is_constant_info() noexcept
+    {
+        return this;
+    }
+
+    std::int32_t constant_info::value() const noexcept
+    {
+        return m_value;
+    }
+
+    variable_info::variable_info(std::shared_ptr<const class type> type)
+        : typed_info(type)
+    {
+    }
+
+    variable_info *variable_info::is_variable_info() noexcept
+    {
+        return this;
+    }
+
+    parameter_info::parameter_info(std::shared_ptr<const class type> type)
+        : typed_info(type)
+    {
+    }
+
+    parameter_info *parameter_info::is_parameter_info() noexcept
+    {
+        return this;
+    }
+
+    intrinsic_info::intrinsic_info(const class procedure_type& type)
+        : m_type(std::make_shared<procedure_type>(type))
+    {
+    }
+
+    intrinsic_info::~intrinsic_info()
+    {
+    }
+
+    std::shared_ptr<const class procedure_type> intrinsic_info::type() const noexcept
+    {
+        return m_type;
+    }
+
+    std::size_t intrinsic_info::parameter_stack_size() const noexcept
+    {
+        return type()->arguments.size() * sizeof(std::int32_t);
+    }
+
+    intrinsic_info *intrinsic_info::is_intrinsic_info() noexcept
+    {
+        return this;
+    }
+
+    procedure_info::procedure_info(const class procedure_type& type, std::shared_ptr<symbol_table> outer_scope)
+        : intrinsic_info(type), local_table(std::make_shared<symbol_table>(outer_scope))
+    {
+    }
+
+    procedure_info::~procedure_info()
+    {
+    }
+
+    std::shared_ptr<symbol_table> procedure_info::scope()
+    {
+        return local_table;
+    }
+
+    std::size_t procedure_info::stack_size() const noexcept
+    {
+        return local_stack_size + argument_stack_size;
+    }
+
+    procedure_info *procedure_info::is_procedure_info() noexcept
+    {
+        return this;
+    }
+
+    constexpr std::size_t pointer_size = 4;
+
+    std::shared_ptr<source::symbol_table> add_builtin_symbols()
+    {
+        source::symbol_table result;
+        std::vector<std::shared_ptr<const source::type>> intrinsic_arguments;
+
+        auto prim = boolean_type;
+        auto boolean_info = std::make_shared<type_info>(std::make_shared<primitive_type>(boolean_type));
+        auto int_info = std::make_shared<source::type_info>(std::make_shared<primitive_type>(int_type));
+        result.enter("Boolean", boolean_info);
+        result.enter("Int", int_info);
+
+        intrinsic_arguments.push_back(int_info->type());
+        auto writei = std::make_shared<source::intrinsic_info>(
+                source::procedure_type{ intrinsic_arguments, pointer_size });
+        result.enter("writei", writei);
+        intrinsic_arguments.clear();
+
+        intrinsic_arguments.push_back(boolean_info->type());
+        auto writeb = std::make_shared<source::intrinsic_info>(
+                source::procedure_type{ intrinsic_arguments, pointer_size });
+        result.enter("writeb", writeb);
+        intrinsic_arguments.clear();
+
+        return std::make_shared<source::symbol_table>(std::move(result));
+    }
+}
+}