diff --git a/.gitignore b/.gitignore
index ce5a7e2..07f3f91 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,5 @@
/doc/*.html
/doc/*.pdf
+
+a.out
diff --git a/COPYING3 b/COPYING3
new file mode 100644
index 0000000..94a9ed0
--- /dev/null
+++ b/COPYING3
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
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+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+
+ Copyright (C)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see .
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ Copyright (C)
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+.
diff --git a/Rakefile b/Rakefile
index da58e7c..9eb4f04 100644
--- a/Rakefile
+++ b/Rakefile
@@ -15,6 +15,7 @@ STAGES = Dir.glob('boot/stage*')
CLEAN.include 'build/boot', 'build/valid'
CLEAN.include 'doc/*.pdf'
+CLOBBER.include 'build'
def compile(*arguments)
sh(ENV.fetch('CC', 'gcc'), '-fpie', '-g', *arguments)
diff --git a/config-lang.in b/config-lang.in
new file mode 100644
index 0000000..1bc1697
--- /dev/null
+++ b/config-lang.in
@@ -0,0 +1,21 @@
+# Top level configure fragment for gcc Elna frontend.
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# .
+
+language="elna"
+gcc_subdir="elna/gcc"
+
+. ${srcdir}/elna/gcc/config-lang.in
diff --git a/frontend/ast.cc b/frontend/ast.cc
new file mode 100644
index 0000000..e067937
--- /dev/null
+++ b/frontend/ast.cc
@@ -0,0 +1,1178 @@
+/* Abstract syntax tree representation.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/ast.h"
+
+namespace elna::frontend
+{
+ void empty_visitor::not_implemented()
+ {
+ __builtin_unreachable();
+ }
+
+ void empty_visitor::visit(named_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(array_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(pointer_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(program *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(type_declaration *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(record_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(union_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(procedure_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(enumeration_type_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(variable_declaration *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(constant_declaration *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(procedure_declaration *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(assign_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(if_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(import_declaration *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(while_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(return_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(defer_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(case_statement *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(procedure_call *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(unit *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(cast_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(traits_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(binary_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(unary_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(variable_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(array_access_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(field_access_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(dereference_expression *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ void empty_visitor::visit(literal *)
+ {
+ not_implemented();
+ }
+
+ node::node(const struct position position)
+ : source_position(position)
+ {
+ }
+
+ node::~node()
+ {
+ }
+
+ const struct position& node::position() const
+ {
+ return this->source_position;
+ }
+
+ cast_expression *expression::is_cast()
+ {
+ return nullptr;
+ }
+
+ traits_expression *expression::is_traits()
+ {
+ return nullptr;
+ }
+
+ binary_expression *expression::is_binary()
+ {
+ return nullptr;
+ }
+
+ unary_expression *expression::is_unary()
+ {
+ return nullptr;
+ }
+
+ designator_expression *expression::is_designator()
+ {
+ return nullptr;
+ }
+
+ procedure_call *expression::is_call_expression()
+ {
+ return nullptr;
+ }
+
+ literal_expression *expression::is_literal()
+ {
+ return nullptr;
+ }
+
+ type_expression::type_expression(const struct position position)
+ : node(position)
+ {
+ }
+
+ named_type_expression *type_expression::is_named()
+ {
+ return nullptr;
+ }
+
+ array_type_expression *type_expression::is_array()
+ {
+ return nullptr;
+ }
+
+ pointer_type_expression *type_expression::is_pointer()
+ {
+ return nullptr;
+ }
+
+ record_type_expression *type_expression::is_record()
+ {
+ return nullptr;
+ }
+
+ union_type_expression *type_expression::is_union()
+ {
+ return nullptr;
+ }
+
+ procedure_type_expression *type_expression::is_procedure()
+ {
+ return nullptr;
+ }
+
+ enumeration_type_expression *type_expression::is_enumeration()
+ {
+ return nullptr;
+ }
+
+ named_type_expression::named_type_expression(const struct position position, const std::string& name)
+ : type_expression(position), name(name)
+ {
+ }
+
+ void named_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ named_type_expression *named_type_expression::is_named()
+ {
+ return this;
+ }
+
+ array_type_expression::array_type_expression(const struct position position,
+ type_expression *base, const std::uint32_t size)
+ : type_expression(position), m_base(base), size(size)
+ {
+ }
+
+ array_type_expression::~array_type_expression()
+ {
+ delete m_base;
+ }
+
+ void array_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ array_type_expression *array_type_expression::is_array()
+ {
+ return this;
+ }
+
+ type_expression& array_type_expression::base()
+ {
+ return *m_base;
+ }
+
+ pointer_type_expression::pointer_type_expression(const struct position position,
+ type_expression *base)
+ : type_expression(position), m_base(base)
+ {
+ }
+
+ pointer_type_expression::~pointer_type_expression()
+ {
+ delete m_base;
+ }
+
+ void pointer_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ pointer_type_expression *pointer_type_expression::is_pointer()
+ {
+ return this;
+ }
+
+ type_expression& pointer_type_expression::base()
+ {
+ return *m_base;
+ }
+
+ record_type_expression::record_type_expression(const struct position position,
+ std::vector&& fields)
+ : type_expression(position), fields(std::move(fields))
+ {
+ }
+
+ record_type_expression::~record_type_expression()
+ {
+ for (const field_declaration& field : this->fields)
+ {
+ delete field.second;
+ }
+ }
+
+ void record_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ record_type_expression *record_type_expression::is_record()
+ {
+ return this;
+ }
+
+ union_type_expression::union_type_expression(const struct position position,
+ std::vector&& fields)
+ : type_expression(position), fields(std::move(fields))
+ {
+ }
+
+ union_type_expression::~union_type_expression()
+ {
+ for (const field_declaration& field : this->fields)
+ {
+ delete field.second;
+ }
+ }
+
+ void union_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ union_type_expression *union_type_expression::is_union()
+ {
+ return this;
+ }
+
+ variable_declaration::variable_declaration(const struct position position,
+ std::vector&& identifier, std::shared_ptr variable_type,
+ expression *body)
+ : node(position), m_variable_type(variable_type), identifiers(std::move(identifier)), body(body)
+ {
+ }
+
+ variable_declaration::variable_declaration(const struct position position,
+ std::vector&& identifier, std::shared_ptr variable_type,
+ std::monostate)
+ : node(position), m_variable_type(variable_type), identifiers(std::move(identifier)), is_extern(true)
+ {
+ }
+
+ void variable_declaration::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ bool variable_declaration::has_initializer() const
+ {
+ return this->is_extern || this->body != nullptr;
+ }
+
+ type_expression& variable_declaration::variable_type()
+ {
+ return *m_variable_type;
+ }
+
+ declaration::declaration(const struct position position, identifier_definition identifier)
+ : node(position), identifier(identifier)
+ {
+ }
+
+ constant_declaration::constant_declaration(const struct position position, identifier_definition identifier,
+ expression *body)
+ : declaration(position, identifier), m_body(body)
+ {
+ }
+
+ void constant_declaration::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& constant_declaration::body()
+ {
+ return *m_body;
+ }
+
+ constant_declaration::~constant_declaration()
+ {
+ delete m_body;
+ }
+
+ procedure_type_expression::procedure_type_expression(const struct position position, return_t return_type)
+ : type_expression(position), return_type(return_type)
+ {
+ }
+
+ procedure_type_expression::~procedure_type_expression()
+ {
+ if (return_type.proper_type != nullptr)
+ {
+ delete return_type.proper_type;
+ }
+ for (const type_expression *parameter : this->parameters)
+ {
+ delete parameter;
+ }
+ }
+
+ void procedure_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ procedure_type_expression *procedure_type_expression::is_procedure()
+ {
+ return this;
+ }
+
+ enumeration_type_expression::enumeration_type_expression(const struct position position, std::vector&& members)
+ : type_expression(position), members(members)
+ {
+ }
+
+ void enumeration_type_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ enumeration_type_expression *enumeration_type_expression::is_enumeration()
+ {
+ return this;
+ }
+
+ procedure_declaration::procedure_declaration(const struct position position, identifier_definition identifier,
+ procedure_type_expression *heading, block&& body)
+ : declaration(position, identifier), m_heading(heading), body(std::move(body))
+ {
+ }
+
+ procedure_declaration::procedure_declaration(const struct position position, identifier_definition identifier,
+ procedure_type_expression *heading)
+ : declaration(position, identifier), m_heading(heading), body(std::nullopt)
+ {
+ }
+
+ void procedure_declaration::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ procedure_type_expression& procedure_declaration::heading()
+ {
+ return *m_heading;
+ }
+
+ procedure_declaration::~procedure_declaration()
+ {
+ delete m_heading;
+ }
+
+ type_declaration::type_declaration(const struct position position, identifier_definition identifier,
+ type_expression *body)
+ : declaration(position, identifier), m_body(body)
+ {
+ }
+
+ type_declaration::~type_declaration()
+ {
+ delete m_body;
+ }
+
+ void type_declaration::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ type_expression& type_declaration::body()
+ {
+ return *m_body;
+ }
+
+ block::block(std::vector&& constants, std::vector&& variables,
+ std::vector&& body)
+ : m_variables(std::move(variables)), m_constants(std::move(constants)), m_body(std::move(body))
+ {
+ }
+
+ block::block(block&& that)
+ : m_variables(std::move(that.m_variables)), m_constants(std::move(that.m_constants)),
+ m_body(std::move(that.m_body))
+ {
+ }
+
+ block& block::operator=(block&& that)
+ {
+ std::swap(m_variables, that.m_variables);
+ std::swap(m_constants, that.m_constants);
+ std::swap(m_body, that.m_body);
+
+ return *this;
+ }
+
+ const std::vector& block::variables()
+ {
+ return m_variables;
+ }
+
+ const std::vector& block::constants()
+ {
+ return m_constants;
+ }
+
+ const std::vector& block::body()
+ {
+ return m_body;
+ }
+
+ block::~block()
+ {
+ for (statement *body_statement : this->body())
+ {
+ delete body_statement;
+ }
+ for (variable_declaration *variable : this->variables())
+ {
+ delete variable;
+ }
+ for (constant_declaration *constant : this->constants())
+ {
+ delete constant;
+ }
+ }
+
+ unit::unit(const struct position position)
+ : node(position)
+ {
+ }
+
+ void unit::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ unit::~unit()
+ {
+ for (procedure_declaration *procedure : this->procedures)
+ {
+ delete procedure;
+ }
+ for (variable_declaration *variable : this->variables)
+ {
+ delete variable;
+ }
+ for (type_declaration *type : this->types)
+ {
+ delete type;
+ }
+ for (constant_declaration *constant : this->constants)
+ {
+ delete constant;
+ }
+ for (import_declaration *declaration : this->imports)
+ {
+ delete declaration;
+ }
+ }
+
+ program::program(const struct position position)
+ : unit(position)
+ {
+ }
+
+ void program::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ program::~program()
+ {
+ for (statement *body_statement : this->body)
+ {
+ delete body_statement;
+ }
+ }
+
+ literal_expression::literal_expression()
+ {
+ }
+
+ literal_expression *literal_expression::is_literal()
+ {
+ return this;
+ }
+
+ defer_statement::defer_statement(const struct position position, std::vector&& statements)
+ : node(position), statements(std::move(statements))
+ {
+ }
+
+ void defer_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ defer_statement::~defer_statement()
+ {
+ for (statement *body_statement : statements)
+ {
+ delete body_statement;
+ }
+ }
+
+ designator_expression::designator_expression()
+ {
+ }
+
+ designator_expression::~designator_expression()
+ {
+ }
+
+ designator_expression *designator_expression::is_designator()
+ {
+ return this;
+ }
+
+ void designator_expression::accept(parser_visitor *visitor)
+ {
+ if (variable_expression *node = is_variable())
+ {
+ return visitor->visit(node);
+ }
+ else if (array_access_expression *node = is_array_access())
+ {
+ return visitor->visit(node);
+ }
+ else if (field_access_expression *node = is_field_access())
+ {
+ return visitor->visit(node);
+ }
+ else if (dereference_expression *node = is_dereference())
+ {
+ return visitor->visit(node);
+ }
+ __builtin_unreachable();
+ }
+
+ variable_expression::variable_expression(const struct position position, const std::string& name)
+ : node(position), name(name)
+ {
+ }
+
+ void variable_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ variable_expression *variable_expression::is_variable()
+ {
+ return this;
+ }
+
+ array_access_expression::array_access_expression(const struct position position,
+ expression *base, expression *index)
+ : node(position), m_base(base), m_index(index)
+ {
+ }
+
+ void array_access_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& array_access_expression::index()
+ {
+ return *m_index;
+ }
+
+ expression& array_access_expression::base()
+ {
+ return *m_base;
+ }
+
+ array_access_expression *array_access_expression::is_array_access()
+ {
+ return this;
+ }
+
+ array_access_expression::~array_access_expression()
+ {
+ delete m_index;
+ delete m_base;
+ }
+
+ field_access_expression::field_access_expression(const struct position position,
+ expression *base, const std::string& field)
+ : node(position), m_base(base), m_field(field)
+ {
+ }
+
+ void field_access_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& field_access_expression::base()
+ {
+ return *m_base;
+ }
+
+ std::string& field_access_expression::field()
+ {
+ return m_field;
+ }
+
+ field_access_expression *field_access_expression::is_field_access()
+ {
+ return this;
+ }
+
+ field_access_expression::~field_access_expression()
+ {
+ delete m_base;
+ }
+
+ dereference_expression::dereference_expression(const struct position position,
+ expression *base)
+ : node(position), m_base(base)
+ {
+ }
+
+ void dereference_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& dereference_expression::base()
+ {
+ return *m_base;
+ }
+
+ dereference_expression *dereference_expression::is_dereference()
+ {
+ return this;
+ }
+
+ dereference_expression::~dereference_expression()
+ {
+ delete m_base;
+ }
+
+ binary_expression::binary_expression(const struct position position, expression *lhs,
+ expression *rhs, const binary_operator operation)
+ : node(position), m_lhs(lhs), m_rhs(rhs), m_operator(operation)
+ {
+ }
+
+ void binary_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ binary_expression *binary_expression::is_binary()
+ {
+ return this;
+ }
+
+ expression& binary_expression::lhs()
+ {
+ return *m_lhs;
+ }
+
+ expression& binary_expression::rhs()
+ {
+ return *m_rhs;
+ }
+
+ binary_operator binary_expression::operation() const
+ {
+ return m_operator;
+ }
+
+ binary_expression::~binary_expression()
+ {
+ delete m_lhs;
+ delete m_rhs;
+ }
+
+ unary_expression::unary_expression(const struct position position, expression *operand,
+ const unary_operator operation)
+ : node(position), m_operand(std::move(operand)), m_operator(operation)
+ {
+ }
+
+ void unary_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ unary_expression *unary_expression::is_unary()
+ {
+ return this;
+ }
+
+ expression& unary_expression::operand()
+ {
+ return *m_operand;
+ }
+
+ unary_operator unary_expression::operation() const
+ {
+ return this->m_operator;
+ }
+
+ unary_expression::~unary_expression()
+ {
+ delete m_operand;
+ }
+
+ procedure_call::procedure_call(const struct position position, designator_expression *callable)
+ : node(position), m_callable(callable)
+ {
+ }
+
+ void procedure_call::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ procedure_call *procedure_call::is_call_expression()
+ {
+ return this;
+ }
+
+ designator_expression& procedure_call::callable()
+ {
+ return *m_callable;
+ }
+
+ procedure_call::~procedure_call()
+ {
+ for (expression *const argument : arguments)
+ {
+ delete argument;
+ }
+ delete m_callable;
+ }
+
+ cast_expression::cast_expression(const struct position position, type_expression *target, expression *value)
+ : node(position), m_target(target), m_value(value)
+ {
+ }
+
+ void cast_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ cast_expression *cast_expression::is_cast()
+ {
+ return this;
+ }
+
+ type_expression& cast_expression::target()
+ {
+ return *m_target;
+ }
+
+ expression& cast_expression::value()
+ {
+ return *m_value;
+ }
+
+ cast_expression::~cast_expression()
+ {
+ delete m_target;
+ delete m_value;
+ }
+
+ traits_expression::traits_expression(const struct position position, const std::string& name)
+ : node(position), name(name)
+ {
+ }
+
+ traits_expression::~traits_expression()
+ {
+ for (const type_expression *parameter : this->parameters)
+ {
+ delete parameter;
+ }
+ }
+
+ void traits_expression::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ traits_expression *traits_expression::is_traits()
+ {
+ return this;
+ }
+
+ conditional_statements::conditional_statements(expression *prerequisite, std::vector&& statements)
+ : m_prerequisite(prerequisite), statements(std::move(statements))
+ {
+ }
+
+ expression& conditional_statements::prerequisite()
+ {
+ return *m_prerequisite;
+ }
+
+ conditional_statements::~conditional_statements()
+ {
+ delete m_prerequisite;
+ for (auto statement : statements)
+ {
+ delete statement;
+ }
+ }
+
+ return_statement::return_statement(const struct position position, expression *return_expression)
+ : node(position), m_return_expression(return_expression)
+ {
+ }
+
+ void return_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& return_statement::return_expression()
+ {
+ return *m_return_expression;
+ }
+
+ return_statement::~return_statement()
+ {
+ delete m_return_expression;
+ }
+
+ case_statement::case_statement(const struct position position,
+ expression *condition, std::vector&& cases, std::vector *alternative)
+ : node(position), m_condition(condition), cases(std::move(cases)), alternative(alternative)
+ {
+ }
+
+ void case_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ expression& case_statement::condition()
+ {
+ return *m_condition;
+ }
+
+ assign_statement::assign_statement(const struct position position, designator_expression *lvalue,
+ expression *rvalue)
+ : node(position), m_lvalue(lvalue), m_rvalue(rvalue)
+ {
+ }
+
+ void assign_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ variable_expression *designator_expression::is_variable()
+ {
+ return nullptr;
+ }
+
+ array_access_expression *designator_expression::is_array_access()
+ {
+ return nullptr;
+ }
+
+ field_access_expression *designator_expression::is_field_access()
+ {
+ return nullptr;
+ }
+
+ dereference_expression *designator_expression::is_dereference()
+ {
+ return nullptr;
+ }
+
+ designator_expression& assign_statement::lvalue()
+ {
+ return *m_lvalue;
+ }
+
+ expression& assign_statement::rvalue()
+ {
+ return *m_rvalue;
+ }
+
+ assign_statement::~assign_statement()
+ {
+ delete m_rvalue;
+ }
+
+ if_statement::if_statement(const struct position position, conditional_statements *body,
+ std::vector&& branches,
+ std::vector *alternative)
+ : node(position), m_body(body), branches(std::move(branches)), alternative(alternative)
+ {
+ }
+
+ void if_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ conditional_statements& if_statement::body()
+ {
+ return *m_body;
+ }
+
+ if_statement::~if_statement()
+ {
+ delete m_body;
+ for (const auto branch : branches)
+ {
+ delete branch;
+ }
+ delete this->alternative;
+ }
+
+ import_declaration::import_declaration(const struct position position, std::vector&& segments)
+ : node(position), segments(std::move(segments))
+ {
+ }
+
+ void import_declaration::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ while_statement::while_statement(const struct position position, conditional_statements *body,
+ std::vector&& branches)
+ : node(position), m_body(body), branches(std::move(branches))
+ {
+ }
+
+ void while_statement::accept(parser_visitor *visitor)
+ {
+ visitor->visit(this);
+ }
+
+ conditional_statements& while_statement::body()
+ {
+ return *m_body;
+ }
+
+ while_statement::~while_statement()
+ {
+ delete m_body;
+ for (const auto branch : branches)
+ {
+ delete branch;
+ }
+ }
+
+ const char *print_binary_operator(const binary_operator operation)
+ {
+ switch (operation)
+ {
+ case binary_operator::sum:
+ return "+";
+ case binary_operator::subtraction:
+ return "-";
+ case binary_operator::multiplication:
+ return "*";
+ case binary_operator::division:
+ return "/";
+ case binary_operator::remainder:
+ return "%";
+ case binary_operator::equals:
+ return "=";
+ case binary_operator::not_equals:
+ return "<>";
+ case binary_operator::less:
+ return "<";
+ case binary_operator::less_equal:
+ return "<=";
+ case binary_operator::greater:
+ return ">";
+ case binary_operator::greater_equal:
+ return ">=";
+ case binary_operator::conjunction:
+ return "and";
+ case binary_operator::disjunction:
+ return "or";
+ case binary_operator::exclusive_disjunction:
+ return "xor";
+ case binary_operator::shift_left:
+ return "<<";
+ case binary_operator::shift_right:
+ return ">>";
+ }
+ __builtin_unreachable();
+ };
+}
diff --git a/frontend/dependency.cc b/frontend/dependency.cc
new file mode 100644
index 0000000..25658f8
--- /dev/null
+++ b/frontend/dependency.cc
@@ -0,0 +1,102 @@
+/* Dependency graph analysis.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/dependency.h"
+
+#include
+#include
+#include
+
+#include "elna/frontend/driver.h"
+#include "elna/frontend/semantic.h"
+#include "parser.hh"
+
+namespace elna::frontend
+{
+ dependency::dependency(const char *path)
+ : error_container(path)
+ {
+ }
+
+ dependency read_source(std::istream& entry_point, const char *entry_path)
+ {
+ driver parse_driver{ entry_path };
+ lexer tokenizer(entry_point);
+ yy::parser parser(tokenizer, parse_driver);
+
+ dependency outcome{ entry_path };
+ if (parser())
+ {
+ std::swap(outcome.errors(), parse_driver.errors());
+ return outcome;
+ }
+ else
+ {
+ std::swap(outcome.tree, parse_driver.tree);
+ }
+ declaration_visitor declaration_visitor(entry_path);
+ outcome.tree->accept(&declaration_visitor);
+
+ if (!declaration_visitor.errors().empty())
+ {
+ std::swap(outcome.errors(), declaration_visitor.errors());
+ }
+ outcome.unresolved = declaration_visitor.unresolved;
+
+ return outcome;
+ }
+
+ error_list analyze_semantics(const char *path, std::unique_ptr& tree, symbol_bag bag)
+ {
+ name_analysis_visitor name_analyser(path, bag);
+ tree->accept(&name_analyser);
+
+ if (name_analyser.has_errors())
+ {
+ return std::move(name_analyser.errors());
+ }
+ type_analysis_visitor type_analyzer(path, bag);
+ tree->accept(&type_analyzer);
+
+ if (type_analyzer.has_errors())
+ {
+ return std::move(type_analyzer.errors());
+ }
+ return error_list{};
+ }
+
+ std::filesystem::path build_path(const std::vector& segments)
+ {
+ std::filesystem::path result;
+ std::vector::const_iterator segment_iterator = std::cbegin(segments);
+
+ if (segment_iterator == std::cend(segments))
+ {
+ return result;
+ }
+ result = *segment_iterator;
+
+ ++segment_iterator;
+ for (; segment_iterator != std::cend(segments); ++segment_iterator)
+ {
+ result /= *segment_iterator;
+ }
+ result.replace_extension(".elna");
+
+ return result;
+ }
+}
diff --git a/frontend/driver.cc b/frontend/driver.cc
new file mode 100644
index 0000000..1c20d09
--- /dev/null
+++ b/frontend/driver.cc
@@ -0,0 +1,124 @@
+/* Parsing driver.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/driver.h"
+
+namespace elna::frontend
+{
+ position make_position(const yy::location& location)
+ {
+ position result;
+ result.line = static_cast(location.begin.line);
+ result.column = static_cast(location.begin.column);
+
+ return result;
+ }
+
+ syntax_error::syntax_error(const std::string& message,
+ const char *input_file, const yy::location& location)
+ : error(input_file, make_position(location)), message(message)
+ {
+ }
+
+ std::string syntax_error::what() const
+ {
+ return message;
+ }
+
+ driver::driver(const char *input_file)
+ : error_container(input_file)
+ {
+ }
+
+ char escape_char(char escape)
+ {
+ switch (escape)
+ {
+ case 'n':
+ return '\n';
+ case 'a':
+ return '\a';
+ case 'b':
+ return '\b';
+ case 't':
+ return '\t';
+ case 'f':
+ return '\f';
+ case 'r':
+ return '\r';
+ case 'v':
+ return '\v';
+ case '\\':
+ return '\\';
+ case '\'':
+ return '\'';
+ case '"':
+ return '"';
+ case '?':
+ return '\?';
+ case '0':
+ return '\0';
+ default:
+ return escape_invalid_char;
+ }
+ }
+
+ std::optional escape_string(const char *escape)
+ {
+ std::string result;
+ const char *current_position = escape + 1;
+
+ while (*current_position != '\0')
+ {
+ if (*current_position == '\\' && *(current_position + 1) == 'x')
+ {
+ current_position += 2;
+
+ std::size_t processed;
+ char character = static_cast(std::stoi(current_position, &processed, 16));
+ if (processed == 0)
+ {
+ return std::nullopt;
+ }
+ else
+ {
+ current_position += processed - 1;
+ result.push_back(character);
+ }
+ }
+ else if (*current_position == '\\')
+ {
+ ++current_position;
+
+ char escape = escape_char(*current_position);
+ if (escape == escape_invalid_char)
+ {
+ return std::nullopt;
+ }
+ result.push_back(escape);
+ }
+ else
+ {
+ result.push_back(*current_position);
+ }
+ ++current_position;
+ }
+ result.pop_back(); // Remove the terminating quote character.
+
+ return result;
+ }
+}
diff --git a/frontend/lexer.ll b/frontend/lexer.ll
new file mode 100644
index 0000000..f14497b
--- /dev/null
+++ b/frontend/lexer.ll
@@ -0,0 +1,320 @@
+/* Lexical analyzer.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+%{
+#define YY_NO_UNISTD_H
+#define YY_USER_ACTION this->location.columns(yyleng);
+
+#include
+#include "parser.hh"
+
+#undef YY_DECL
+#define YY_DECL yy::parser::symbol_type elna::frontend::lexer::lex(driver& driver)
+#define yyterminate() return yy::parser::make_YYEOF(this->location)
+%}
+
+%option c++ noyywrap never-interactive
+%option yyclass="lexer"
+
+%x IN_COMMENT
+
+ID1 [A-Za-z_]
+ID2 [A-Za-z0-9_]
+HIGIT [0-9a-fA-F]
+BIGIT [01]
+
+%%
+%{
+ this->location.step();
+%}
+
+{
+ \*\) BEGIN(INITIAL);
+ [^*\n]+ ; /* Eat comment in chunks. */
+ \* ; /* Eat the lone star. */
+ \n+ {
+ this->location.lines(yyleng);
+ this->location.step();
+ }
+}
+\(\* BEGIN(IN_COMMENT);
+[ \t\r] {
+ this->location.step();
+}
+\n+ {
+ this->location.lines(yyleng);
+}
+if {
+ return yy::parser::make_IF(this->location);
+}
+then {
+ return yy::parser::make_THEN(this->location);
+}
+else {
+ return yy::parser::make_ELSE(this->location);
+}
+elsif {
+ return yy::parser::make_ELSIF(this->location);
+}
+while {
+ return yy::parser::make_WHILE(this->location);
+}
+do {
+ return yy::parser::make_DO(this->location);
+}
+proc {
+ return yy::parser::make_PROCEDURE(this->location);
+}
+begin {
+ return yy::parser::make_BEGIN_BLOCK(this->location);
+ }
+end {
+ return yy::parser::make_END_BLOCK(this->location);
+}
+extern {
+ return yy::parser::make_EXTERN(this->location);
+}
+const {
+ return yy::parser::make_CONST(this->location);
+}
+var {
+ return yy::parser::make_VAR(this->location);
+}
+type {
+ return yy::parser::make_TYPE(this->location);
+}
+record {
+ return yy::parser::make_RECORD(this->location);
+}
+union {
+ return yy::parser::make_UNION(this->location);
+}
+true {
+ return yy::parser::make_BOOLEAN(true, this->location);
+}
+false {
+ return yy::parser::make_BOOLEAN(false, this->location);
+}
+nil {
+ return yy::parser::make_NIL(this->location);
+}
+\& {
+ return yy::parser::make_AND(this->location);
+}
+xor {
+ return yy::parser::make_XOR(this->location);
+}
+or {
+ return yy::parser::make_OR(this->location);
+}
+\| {
+ return yy::parser::make_PIPE(this->location);
+}
+\~ {
+ return yy::parser::make_NOT(this->location);
+}
+return {
+ return yy::parser::make_RETURN(this->location);
+}
+module {
+ return yy::parser::make_MODULE(this->location);
+}
+program {
+ return yy::parser::make_PROGRAM(this->location);
+}
+import {
+ return yy::parser::make_IMPORT(this->location);
+}
+cast {
+ return yy::parser::make_CAST(this->location);
+}
+defer {
+ return yy::parser::make_DEFER(this->location);
+}
+case {
+ return yy::parser::make_CASE(this->location);
+}
+of {
+ return yy::parser::make_OF(this->location);
+}
+{ID1}{ID2}* {
+ return yy::parser::make_IDENTIFIER(yytext, this->location);
+}
+#{ID1}{ID2}* {
+ return yy::parser::make_TRAIT(yytext + 1, this->location);
+}
+[[:digit:]]+u {
+ unsigned long result = strtoul(yytext, NULL, 10);
+
+ if (errno == ERANGE)
+ {
+ REJECT;
+ }
+ else
+ {
+ return yy::parser::make_WORD(result, this->location);
+ }
+}
+[[:digit:]]+ {
+ long result = strtol(yytext, NULL, 10);
+
+ if (errno == ERANGE)
+ {
+ REJECT;
+ }
+ else
+ {
+ return yy::parser::make_INTEGER(result, this->location);
+ }
+}
+0x{HIGIT}+ {
+ unsigned long result = strtoul(yytext, NULL, 16);
+
+ if (errno == ERANGE)
+ {
+ REJECT;
+ }
+ else
+ {
+ return yy::parser::make_WORD(result, this->location);
+ }
+}
+0b{BIGIT}+ {
+ unsigned long result = strtoul(yytext, NULL, 2);
+
+ if (errno == ERANGE)
+ {
+ REJECT;
+ }
+ else
+ {
+ return yy::parser::make_WORD(result, this->location);
+ }
+}
+[[:digit:]]+\.[[:digit:]]+ {
+ float result = strtof(yytext, NULL);
+
+ if (errno == ERANGE)
+ {
+ REJECT;
+ }
+ else
+ {
+ return yy::parser::make_FLOAT(result, this->location);
+ }
+}
+'[[:print:]]+' {
+ std::optional result = escape_string(yytext);
+ if (!result.has_value() || result.value().size() != 1)
+ {
+ REJECT;
+ }
+ return yy::parser::make_CHARACTER(result.value(), this->location);
+}
+\"[[:print:]]*\" {
+ std::optional result = escape_string(yytext);
+ if (!result.has_value())
+ {
+ REJECT;
+ }
+ return yy::parser::make_STRING(result.value(), this->location);
+}
+\( {
+ return yy::parser::make_LEFT_PAREN(this->location);
+}
+\) {
+ return yy::parser::make_RIGHT_PAREN(this->location);
+}
+\[ {
+ return yy::parser::make_LEFT_SQUARE(this->location);
+}
+\] {
+ return yy::parser::make_RIGHT_SQUARE(this->location);
+}
+\<\< {
+ return yy::parser::make_SHIFT_LEFT(this->location);
+}
+\>\> {
+ return yy::parser::make_SHIFT_RIGHT(this->location);
+}
+\>= {
+ return yy::parser::make_GREATER_EQUAL(this->location);
+}
+\<= {
+ return yy::parser::make_LESS_EQUAL(this->location);
+}
+\> {
+ return yy::parser::make_GREATER_THAN(this->location);
+}
+\< {
+ return yy::parser::make_LESS_THAN(this->location);
+}
+\<\> {
+ return yy::parser::make_NOT_EQUAL(this->location);
+}
+= {
+ return yy::parser::make_EQUALS(this->location);
+}
+; {
+ return yy::parser::make_SEMICOLON(this->location);
+}
+\. {
+ return yy::parser::make_DOT(this->location);
+}
+, {
+ return yy::parser::make_COMMA(this->location);
+}
+\+ {
+ return yy::parser::make_PLUS(this->location);
+}
+\-> {
+ return yy::parser::make_ARROW(this->location);
+}
+\- {
+ return yy::parser::make_MINUS(this->location);
+}
+\* {
+ return yy::parser::make_MULTIPLICATION(this->location);
+}
+\/ {
+ return yy::parser::make_DIVISION(this->location);
+}
+% {
+ return yy::parser::make_REMAINDER(this->location);
+}
+:= {
+ return yy::parser::make_ASSIGNMENT(this->location);
+}
+: {
+ return yy::parser::make_COLON(this->location);
+}
+\^ {
+ return yy::parser::make_HAT(this->location);
+}
+@ {
+ return yy::parser::make_AT(this->location);
+}
+! {
+ return yy::parser::make_EXCLAMATION(this->location);
+}
+. {
+ std::stringstream ss;
+
+ ss << "Illegal character 0x" << std::hex << static_cast(yytext[0]);
+ driver.add_error(ss.str(), driver.input_file, this->location);
+}
+%%
diff --git a/frontend/parser.yy b/frontend/parser.yy
new file mode 100644
index 0000000..bace8d7
--- /dev/null
+++ b/frontend/parser.yy
@@ -0,0 +1,594 @@
+/* Syntax analyzer.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+%require "3.4"
+%language "c++"
+
+%code {
+ using namespace elna;
+}
+
+%code requires {
+ #include
+ #include
+ #include "elna/frontend/driver.h"
+
+ #if !defined(yyFlexLexerOnce)
+ #include
+ #endif
+
+ namespace elna::frontend
+ {
+ class lexer;
+ }
+}
+
+%code provides {
+ namespace elna::frontend
+ {
+
+ class lexer: public yyFlexLexer
+ {
+ public:
+ yy::location location;
+
+ lexer(std::istream& arg_yyin)
+ : yyFlexLexer(&arg_yyin)
+ {
+ }
+
+ yy::parser::symbol_type lex(driver& driver);
+ };
+
+ }
+}
+
+%define api.token.raw
+%define api.token.constructor
+%define api.value.type variant
+
+%parse-param {elna::frontend::lexer& lexer}
+%param {elna::frontend::driver& driver}
+%locations
+
+%header
+
+%code {
+ #define yylex lexer.lex
+}
+%start program;
+
+%token IDENTIFIER
+%token TRAIT
+%token INTEGER
+%token WORD
+%token FLOAT
+%token CHARACTER
+%token STRING
+%token BOOLEAN
+%token LEFT_PAREN "(" RIGHT_PAREN ")" LEFT_SQUARE "[" RIGHT_SQUARE "]"
+%token ASSIGNMENT ":="
+ ARROW "->" EXCLAMATION "!"
+ AT "@" HAT "^"
+ COLON ":" SEMICOLON ";" DOT "." COMMA ","
+%token NOT "~"
+ CAST "cast"
+ NIL "nil"
+ CONST "const"
+ VAR "var"
+ PROCEDURE "proc"
+ TYPE "type"
+ RECORD "record"
+ UNION "union"
+ EXTERN "extern"
+ IF "if"
+ WHILE "while"
+ DO "do"
+ THEN "then"
+ ELSE "else"
+ ELSIF "elsif"
+ RETURN "return"
+ PROGRAM "program"
+ MODULE "module"
+ IMPORT "import"
+ BEGIN_BLOCK "begin"
+ END_BLOCK "end"
+ DEFER "defer"
+ CASE "case"
+ OF "of"
+ PIPE "|"
+%token OR "or" AND "&" XOR "xor"
+ EQUALS "=" NOT_EQUAL "<>" LESS_THAN "<" GREATER_THAN ">" LESS_EQUAL "<=" GREATER_EQUAL ">="
+ SHIFT_LEFT "<<" SHIFT_RIGHT ">>"
+ PLUS "+" MINUS "-"
+ MULTIPLICATION "*" DIVISION "/" REMAINDER "%"
+
+%left "or" "&" "xor"
+%left "=" "<>" "<" ">" "<=" ">="
+%left "<<" ">>"
+%left "+" "-"
+%left "*" "/" "%"
+
+%type literal;
+%type > case_labels;
+%type switch_case;
+%type > switch_cases;
+%type constant_declaration;
+%type > constant_part constant_declarations;
+%type variable_declaration;
+%type > variable_declarations variable_part;
+%type type_expression;
+%type > type_expressions;
+%type traits_expression;
+%type expression operand simple_expression;
+%type unary_expression;
+%type binary_expression;
+%type > expressions actual_parameter_list;
+%type designator_expression;
+%type call_expression;
+%type return_statement;
+%type statement;
+%type > required_statements optional_statements statement_part;
+%type procedure_declaration;
+%type , elna::frontend::procedure_type_expression *>> procedure_heading;
+%type return_declaration;
+%type > procedure_declarations procedure_part;
+%type type_declaration;
+%type > type_declarations type_part;
+%type > block;
+%type field_declaration formal_parameter;
+%type >>
+ optional_fields required_fields formal_parameters formal_parameter_list;
+%type > elsif_then_statements elsif_do_statements;
+%type *> else_statements;
+%type cast_expression;
+%type identifier_definition;
+%type > identifier_definitions;
+%type > identifiers import_declaration;
+%type > import_declarations import_part;
+%%
+program:
+ "program" ";" import_part constant_part type_part variable_part procedure_part statement_part "end" "."
+ {
+ auto tree = new frontend::program(frontend::make_position(@1));
+
+ std::swap(tree->imports, $3);
+ std::swap(tree->constants, $4);
+ std::swap(tree->types , $5);
+ std::swap(tree->variables, $6);
+ std::swap(tree->procedures, $7);
+ std::swap(tree->body, $8);
+
+ driver.tree.reset(tree);
+ }
+ | "module" ";" import_part constant_part type_part variable_part procedure_part "end" "."
+ {
+ auto tree = new frontend::unit(frontend::make_position(@1));
+
+ std::swap(tree->imports, $3);
+ std::swap(tree->constants, $4);
+ std::swap(tree->types , $5);
+ std::swap(tree->variables, $6);
+ std::swap(tree->procedures, $7);
+
+ driver.tree.reset(tree);
+ }
+block: constant_part variable_part statement_part "end"
+ {
+ $$ = std::make_unique(std::move($1), std::move($2), std::move($3));
+ }
+statement_part:
+ /* no statements */ {}
+ | "begin" required_statements { std::swap($$, $2); }
+ | return_statement { $$.push_back($1); }
+ | "begin" required_statements ";" return_statement
+ {
+ std::swap($$, $2);
+ $$.push_back($4);
+ }
+identifier_definition:
+ IDENTIFIER "*" { $$ = frontend::identifier_definition{ $1, true }; }
+ | IDENTIFIER { $$ = frontend::identifier_definition{ $1, false }; }
+identifier_definitions:
+ identifier_definition "," identifier_definitions
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | identifier_definition { $$.emplace_back(std::move($1)); }
+return_declaration:
+ /* proper procedure */ {}
+ | "->" "!" { $$ = frontend::procedure_type_expression::return_t(std::monostate{}); }
+ | "->" type_expression { $$ = frontend::procedure_type_expression::return_t($2); }
+procedure_heading: formal_parameter_list return_declaration
+ {
+ $$.second = new frontend::procedure_type_expression(frontend::make_position(@1), std::move($2));
+ for (auto& [name, type] : $1)
+ {
+ $$.first.emplace_back(std::move(name));
+ $$.second->parameters.push_back(type);
+ }
+ }
+procedure_declaration:
+ "proc" identifier_definition procedure_heading ";" block ";"
+ {
+ $$ = new frontend::procedure_declaration(frontend::make_position(@1), std::move($2), $3.second, std::move(*$5));
+ std::swap($3.first, $$->parameter_names);
+ }
+ | "proc" identifier_definition procedure_heading ";" "extern" ";"
+ {
+ $$ = new frontend::procedure_declaration(frontend::make_position(@1), std::move($2), $3.second);
+ std::swap($3.first, $$->parameter_names);
+ }
+procedure_declarations:
+ procedure_declaration procedure_declarations
+ {
+ std::swap($$, $2);
+ $$.emplace($$.cbegin(), std::move($1));
+ }
+ | procedure_declaration { $$.emplace_back(std::move($1)); }
+procedure_part:
+ /* no procedure definitions */ {}
+ | procedure_declarations { std::swap($$, $1); }
+call_expression: designator_expression actual_parameter_list
+ {
+ $$ = new frontend::procedure_call(frontend::make_position(@1), $1);
+ std::swap($$->arguments, $2);
+ }
+cast_expression: "cast" "(" expression ":" type_expression ")"
+ { $$ = new frontend::cast_expression(frontend::make_position(@1), $5, $3); }
+elsif_do_statements:
+ "elsif" expression "do" optional_statements elsif_do_statements
+ {
+ frontend::conditional_statements *branch = new frontend::conditional_statements($2, std::move($4));
+ std::swap($5, $$);
+ $$.emplace($$.begin(), branch);
+ }
+ | {}
+else_statements:
+ "else" optional_statements { $$ = new std::vector(std::move($2)); }
+ | { $$ = nullptr; }
+elsif_then_statements:
+ "elsif" expression "then" optional_statements elsif_then_statements
+ {
+ frontend::conditional_statements *branch = new frontend::conditional_statements($2, std::move($4));
+ std::swap($5, $$);
+ $$.emplace($$.begin(), branch);
+ }
+ | {}
+return_statement: "return" expression
+ { $$ = new frontend::return_statement(frontend::make_position(@1), $2); }
+literal:
+ INTEGER { $$ = new frontend::literal(frontend::make_position(@1), $1); }
+ | WORD { $$ = new frontend::literal(frontend::make_position(@1), $1); }
+ | FLOAT { $$ = new frontend::literal(frontend::make_position(@1), $1); }
+ | BOOLEAN { $$ = new frontend::literal(frontend::make_position(@1), $1); }
+ | CHARACTER { $$ = new frontend::literal(frontend::make_position(@1), $1.at(0)); }
+ | "nil" { $$ = new frontend::literal(frontend::make_position(@1), nullptr); }
+ | STRING { $$ = new frontend::literal(frontend::make_position(@1), $1); }
+traits_expression:
+ TRAIT "(" type_expressions ")"
+ {
+ $$ = new frontend::traits_expression(frontend::make_position(@1), $1);
+ std::swap($3, $$->parameters);
+ }
+simple_expression:
+ literal { $$ = $1; }
+ | designator_expression { $$ = $1; }
+ | traits_expression { $$ = $1; }
+ | cast_expression { $$ = $1; }
+ | call_expression { $$ = $1; }
+ | "(" expression ")" { $$ = $2; }
+operand:
+ unary_expression { $$ = $1; }
+ | simple_expression { $$ = $1; }
+expression:
+ binary_expression { $$ = $1; }
+ | operand { $$ = $1; }
+binary_expression:
+ expression "*" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::multiplication);
+ }
+ | expression "/" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::division);
+ }
+ | expression "%" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::remainder);
+ }
+ | expression "+" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::sum);
+ }
+ | expression "-" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::subtraction);
+ }
+ | expression "=" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::equals);
+ }
+ | expression "<>" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::not_equals);
+ }
+ | expression "<" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::less);
+ }
+ | expression ">" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::greater);
+ }
+ | expression "<=" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3,
+ frontend::binary_operator::less_equal);
+ }
+ | expression ">=" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::greater_equal);
+ }
+ | expression "&" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::conjunction);
+ }
+ | expression "or" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::disjunction);
+ }
+ | expression "xor" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3,
+ frontend::binary_operator::exclusive_disjunction);
+ }
+ | expression "<<" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::shift_left);
+ }
+ | expression ">>" expression
+ {
+ $$ = new frontend::binary_expression(frontend::make_position(@2), $1, $3, frontend::binary_operator::shift_right);
+ }
+unary_expression:
+ "@" operand
+ {
+ $$ = new frontend::unary_expression(frontend::make_position(@1), $2, frontend::unary_operator::reference);
+ }
+ | "~" operand
+ {
+ $$ = new frontend::unary_expression(frontend::make_position(@1), $2, frontend::unary_operator::negation);
+ }
+ | "-" operand
+ {
+ $$ = new frontend::unary_expression(frontend::make_position(@1), $2, frontend::unary_operator::minus);
+ }
+expressions:
+ expression "," expressions
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | expression { $$.push_back($1); }
+type_expressions:
+ type_expression "," type_expressions
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | type_expression { $$.push_back($1); }
+designator_expression:
+ simple_expression "[" expression "]"
+ { $$ = new frontend::array_access_expression(frontend::make_position(@2), $1, $3); }
+ | simple_expression "." IDENTIFIER
+ { $$ = new frontend::field_access_expression(frontend::make_position(@2), $1, $3); }
+ | simple_expression "^"
+ { $$ = new frontend::dereference_expression(frontend::make_position(@1), $1); }
+ | IDENTIFIER
+ { $$ = new frontend::variable_expression(frontend::make_position(@1), $1); }
+statement:
+ designator_expression ":=" expression
+ { $$ = new frontend::assign_statement(frontend::make_position(@1), $1, $3); }
+ | "while" expression "do" optional_statements elsif_do_statements "end"
+ {
+ frontend::conditional_statements *body = new frontend::conditional_statements($2, std::move($4));
+ $$ = new frontend::while_statement(frontend::make_position(@1), body, std::move($5));
+ }
+ | "if" expression "then" optional_statements elsif_then_statements else_statements "end"
+ {
+ frontend::conditional_statements *then = new frontend::conditional_statements($2, std::move($4));
+ $$ = new frontend::if_statement(frontend::make_position(@1), then, std::move($5), $6);
+ }
+ | call_expression { $$ = $1; }
+ | "defer" optional_statements "end"
+ { $$ = new frontend::defer_statement(frontend::make_position(@1), std::move($2)); }
+ | "case" expression "of" switch_cases else_statements "end"
+ { $$ = new frontend::case_statement(frontend::make_position(@1), $2, std::move($4), $5); }
+switch_case: case_labels ":" optional_statements
+ { $$ = { .labels = std::move($1), .statements = std::move($3) }; }
+switch_cases:
+ switch_case "|" switch_cases
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | switch_case { $$.push_back($1); }
+case_labels:
+ expression "," case_labels
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | expression { $$.push_back($1); }
+required_statements:
+ required_statements ";" statement
+ {
+ std::swap($$, $1);
+ $$.insert($$.cend(), $3);
+ }
+ | statement { $$.push_back($1); }
+optional_statements:
+ required_statements { std::swap($$, $1); }
+ | /* no statements */ {}
+field_declaration:
+ IDENTIFIER ":" type_expression { $$ = std::make_pair($1, $3); }
+required_fields:
+ field_declaration ";" required_fields
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), $1);
+ }
+ | field_declaration { $$.emplace_back($1); }
+optional_fields:
+ required_fields { std::swap($$, $1); }
+ | /* no fields */ {}
+type_expression:
+ "[" INTEGER "]" type_expression
+ {
+ $$ = new frontend::array_type_expression(frontend::make_position(@1), $4, $2);
+ }
+ | "^" type_expression
+ {
+ $$ = new frontend::pointer_type_expression(frontend::make_position(@1), $2);
+ }
+ | "record" optional_fields "end"
+ {
+ $$ = new frontend::record_type_expression(frontend::make_position(@1), std::move($2));
+ }
+ | "union" required_fields "end"
+ {
+ $$ = new frontend::union_type_expression(frontend::make_position(@1), std::move($2));
+ }
+ | "proc" "(" type_expressions ")" return_declaration
+ {
+ auto result = new frontend::procedure_type_expression(frontend::make_position(@1), std::move($5));
+ std::swap(result->parameters, $3);
+ $$ = result;
+ }
+ | "(" identifiers ")"
+ {
+ $$ = new frontend::enumeration_type_expression(frontend::make_position(@1), std::move($2));
+ }
+ | IDENTIFIER
+ {
+ $$ = new frontend::named_type_expression(frontend::make_position(@1), $1);
+ }
+identifiers:
+ IDENTIFIER "," identifiers
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), std::move($1));
+ }
+ | IDENTIFIER { $$.emplace_back(std::move($1)); }
+variable_declaration:
+ identifier_definitions ":" type_expression ";"
+ {
+ std::shared_ptr shared_type{ $3 };
+ $$ = new frontend::variable_declaration( frontend::make_position(@2), std::move($1), shared_type);
+ }
+ | identifier_definitions ":" type_expression ":=" "extern" ";"
+ {
+ std::shared_ptr shared_type{ $3 };
+ $$ = new frontend::variable_declaration( frontend::make_position(@2), std::move($1), shared_type,
+ std::monostate{});
+ }
+ | identifier_definitions ":" type_expression ":=" expression ";"
+ {
+ std::shared_ptr shared_type{ $3 };
+ $$ = new frontend::variable_declaration( frontend::make_position(@2), std::move($1), shared_type, $5);
+ }
+variable_declarations:
+ /* no variable declarations */ {}
+ | variable_declaration variable_declarations
+ {
+ std::swap($$, $2);
+ $$.insert(std::cbegin($$), $1);
+ }
+variable_part:
+ /* no variable declarations */ {}
+ | "var" variable_declarations { std::swap($$, $2); }
+constant_declaration: identifier_definition ":=" expression ";"
+ {
+ $$ = new frontend::constant_declaration(frontend::make_position(@1), std::move($1), $3);
+ }
+constant_declarations:
+ constant_declaration constant_declarations
+ {
+ std::swap($$, $2);
+ $$.insert(std::cbegin($$), $1);
+ }
+ | /* no constant definitions */ {}
+constant_part:
+ /* no constant definitions */ {}
+ | "const" constant_declarations { std::swap($$, $2); }
+import_declaration:
+ IDENTIFIER "." import_declaration
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), std::move($1));
+ }
+ | IDENTIFIER { $$.emplace_back(std::move($1)); }
+import_declarations:
+ import_declaration "," import_declarations
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), new frontend::import_declaration(frontend::make_position(@1), std::move($1)));
+ }
+ | import_declaration
+ {
+ $$.emplace_back(new frontend::import_declaration(frontend::make_position(@1), std::move($1)));
+ }
+import_part:
+ /* no import declarations */ {}
+ | "import" import_declarations ";" { std::swap($$, $2); }
+type_declaration: identifier_definition "=" type_expression ";"
+ {
+ $$ = new frontend::type_declaration(frontend::make_position(@1), std::move($1), $3);
+ }
+type_declarations:
+ type_declaration type_declarations
+ {
+ std::swap($$, $2);
+ $$.insert($$.cbegin(), $1);
+ }
+ | /* no type definitions */ {}
+type_part:
+ /* no type definitions */ {}
+ | "type" type_declarations { std::swap($$, $2); }
+formal_parameter:
+ IDENTIFIER ":" type_expression { $$ = std::make_pair($1, $3); }
+formal_parameter_list:
+ "(" ")" {}
+ | "(" formal_parameters ")" { std::swap($$, $2); }
+formal_parameters:
+ formal_parameter "," formal_parameters
+ {
+ std::swap($$, $3);
+ $$.emplace($$.cbegin(), std::move($1));
+ }
+ | formal_parameter { $$.emplace_back(std::move($1)); }
+actual_parameter_list:
+ "(" ")" {}
+ | "(" expressions ")" { std::swap($$, $2); }
+%%
+
+void yy::parser::error(const location_type& loc, const std::string& message)
+{
+ driver.add_error(message, driver.input_file, loc);
+}
diff --git a/frontend/result.cc b/frontend/result.cc
new file mode 100644
index 0000000..aca9c5e
--- /dev/null
+++ b/frontend/result.cc
@@ -0,0 +1,67 @@
+/* Miscellaneous types used across stage boundaries.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/result.h"
+
+namespace elna::frontend
+{
+ error::error(const char *path, const struct position position)
+ : position(position), path(path)
+ {
+ }
+
+ std::size_t error::line() const noexcept
+ {
+ return this->position.line;
+ }
+
+ std::size_t error::column() const noexcept
+ {
+ return this->position.column;
+ }
+
+ error_container::error_container(const char *input_file)
+ : input_file(input_file)
+ {
+ }
+
+ std::deque>& error_container::errors()
+ {
+ return m_errors;
+ }
+
+ bool error_container::has_errors() const
+ {
+ return !m_errors.empty();
+ }
+
+ bool identifier_definition::operator==(const identifier_definition& that) const
+ {
+ return *this == that.name;
+ }
+
+ bool identifier_definition::operator==(const std::string& that) const
+ {
+ return this->name == that;
+ }
+}
+
+std::size_t std::hash::operator()(
+ const elna::frontend::identifier_definition& key) const
+{
+ return std::hash{}(key.name);
+}
diff --git a/frontend/semantic.cc b/frontend/semantic.cc
new file mode 100644
index 0000000..36c75b8
--- /dev/null
+++ b/frontend/semantic.cc
@@ -0,0 +1,644 @@
+/* Name analysis.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/semantic.h"
+
+#include
+#include
+
+namespace elna::frontend
+{
+ undeclared_error::undeclared_error(const std::string& identifier, const char *path, const struct position position)
+ : error(path, position), identifier(identifier)
+ {
+ }
+
+ std::string undeclared_error::what() const
+ {
+ return "Type '" + identifier + "' not declared";
+ }
+
+ already_declared_error::already_declared_error(const std::string& identifier,
+ const char *path, const struct position position)
+ : error(path, position), identifier(identifier)
+ {
+ }
+
+ std::string already_declared_error::what() const
+ {
+ return "Symbol '" + identifier + "' has been already declared";
+ }
+
+ field_duplication_error::field_duplication_error(const std::string& field_name,
+ const char *path, const struct position position)
+ : error(path, position), field_name(field_name)
+ {
+ }
+
+ std::string field_duplication_error::what() const
+ {
+ return "Repeated field name '" + field_name + "'";
+ }
+
+ cyclic_declaration_error::cyclic_declaration_error(const std::vector& cycle,
+ const char *path, const struct position position)
+ : error(path, position), cycle(cycle)
+ {
+ }
+
+ std::string cyclic_declaration_error::what() const
+ {
+ auto segment = std::cbegin(this->cycle);
+ std::string message = "Type declaration forms a cycle: " + *segment;
+
+ ++segment;
+ for (; segment != std::cend(this->cycle); ++segment)
+ {
+ message += " -> " + *segment;
+ }
+ return message;
+ }
+
+ return_error::return_error(const std::string& identifier, const char *path, const struct position position)
+ : error(path, position), identifier(identifier)
+ {
+ }
+
+ std::string return_error::what() const
+ {
+ return "Procedure '" + identifier + "' is expected to return, but does not have a return statement";
+ }
+
+ variable_initializer_error::variable_initializer_error(const char *path, const struct position position)
+ : error(path, position)
+ {
+ }
+
+ std::string variable_initializer_error::what() const
+ {
+ return "Only one variable can be initialized";
+ }
+
+ type_analysis_visitor::type_analysis_visitor(const char *path, symbol_bag bag)
+ : error_container(path), bag(bag)
+ {
+ }
+
+ void type_analysis_visitor::visit(program *program)
+ {
+ visit(static_cast(program));
+ }
+
+ void type_analysis_visitor::visit(procedure_declaration *definition)
+ {
+ if (definition->body.has_value() && definition->heading().return_type.proper_type != nullptr)
+ {
+ for (statement *const statement : definition->body.value().body())
+ {
+ statement->accept(this);
+ }
+ if (!this->returns)
+ {
+ add_error(definition->identifier.name, this->input_file, definition->position());
+ }
+ }
+ }
+
+ void type_analysis_visitor::visit(assign_statement *)
+ {
+ }
+
+ void type_analysis_visitor::visit(if_statement *)
+ {
+ }
+
+ void type_analysis_visitor::visit(while_statement *)
+ {
+ }
+
+ void type_analysis_visitor::visit(return_statement *)
+ {
+ this->returns = true;
+ }
+
+ void type_analysis_visitor::visit(defer_statement *)
+ {
+ }
+
+ void type_analysis_visitor::visit(case_statement *)
+ {
+ }
+
+ void type_analysis_visitor::visit(procedure_call *)
+ {
+ }
+
+ bool type_analysis_visitor::check_unresolved_symbol(std::shared_ptr alias,
+ std::vector& alias_path)
+ {
+ if (std::find(std::cbegin(alias_path), std::cend(alias_path), alias->name) != std::cend(alias_path))
+ {
+ return false;
+ }
+ alias_path.push_back(alias->name);
+
+ if (auto another_alias = alias->reference.get())
+ {
+ return check_unresolved_symbol(another_alias, alias_path);
+ }
+ return true;
+ }
+
+ void type_analysis_visitor::visit(unit *unit)
+ {
+ for (type_declaration *const type : unit->types)
+ {
+ type->accept(this);
+ }
+ for (procedure_declaration *const procedure : unit->procedures)
+ {
+ this->returns = false;
+ procedure->accept(this);
+ }
+ }
+
+ void type_analysis_visitor::visit(type_declaration *definition)
+ {
+ std::vector alias_path;
+ auto unresolved_type = this->bag.lookup(definition->identifier.name)->is_type()->symbol.get();
+
+ if (!check_unresolved_symbol(unresolved_type, alias_path))
+ {
+ add_error(alias_path, this->input_file, definition->position());
+ }
+ }
+
+ name_analysis_visitor::name_analysis_visitor(const char *path, symbol_bag bag)
+ : error_container(path), bag(bag)
+ {
+ }
+
+ procedure_type name_analysis_visitor::build_procedure(procedure_type_expression& type_expression)
+ {
+ procedure_type::return_t result_return;
+
+ if (type_expression.return_type.no_return)
+ {
+ result_return = procedure_type::return_t(std::monostate{});
+ }
+ else if (type_expression.return_type.proper_type != nullptr)
+ {
+ type_expression.return_type.proper_type->accept(this);
+ result_return = procedure_type::return_t(this->current_type);
+ }
+ else
+ {
+ result_return = procedure_type::return_t();
+ }
+ procedure_type result_type = procedure_type(result_return);
+
+ for (struct type_expression *parameter : type_expression.parameters)
+ {
+ parameter->accept(this);
+ result_type.parameters.push_back(this->current_type);
+ }
+ return result_type;
+ }
+
+ void name_analysis_visitor::visit(program *program)
+ {
+ visit(static_cast(program));
+
+ for (statement *const statement : program->body)
+ {
+ statement->accept(this);
+ }
+ }
+
+ void name_analysis_visitor::visit(type_declaration *definition)
+ {
+ definition->body().accept(this);
+ auto resolved = this->bag.resolve(definition->identifier.name, this->current_type);
+ auto info = std::make_shared(type(resolved));
+
+ info->exported = definition->identifier.exported;
+ this->bag.enter(definition->identifier.name, info);
+ }
+
+ void name_analysis_visitor::visit(named_type_expression *type_expression)
+ {
+ auto unresolved_alias = this->bag.declared(type_expression->name);
+
+ if (unresolved_alias != nullptr)
+ {
+ this->current_type = type(unresolved_alias);
+ }
+ else if (auto from_symbol_table = this->bag.lookup(type_expression->name))
+ {
+ this->current_type = from_symbol_table->is_type()->symbol;
+ }
+ else
+ {
+ add_error(type_expression->name, this->input_file, type_expression->position());
+ this->current_type = type();
+ }
+ }
+
+ void name_analysis_visitor::visit(pointer_type_expression *type_expression)
+ {
+ type_expression->base().accept(this);
+ this->current_type = type(std::make_shared(this->current_type));
+ }
+
+ void name_analysis_visitor::visit(array_type_expression *type_expression)
+ {
+ type_expression->base().accept(this);
+ this->current_type = type(std::make_shared(this->current_type, type_expression->size));
+ }
+
+ std::vector name_analysis_visitor::build_composite_type(const std::vector& fields)
+ {
+ std::vector result;
+ std::set field_names;
+
+ for (auto& field : fields)
+ {
+ if (field_names.find(field.first) != field_names.cend())
+ {
+ add_error(field.first, this->input_file, field.second->position());
+ }
+ else
+ {
+ field_names.insert(field.first);
+ field.second->accept(this);
+ result.push_back(std::make_pair(field.first, this->current_type));
+ }
+ }
+ return result;
+ }
+
+ void name_analysis_visitor::visit(record_type_expression *type_expression)
+ {
+ auto result_type = std::make_shared();
+
+ result_type->fields = build_composite_type(type_expression->fields);
+
+ this->current_type = type(result_type);
+ }
+
+ void name_analysis_visitor::visit(union_type_expression *type_expression)
+ {
+ auto result_type = std::make_shared();
+
+ result_type->fields = build_composite_type(type_expression->fields);
+
+ this->current_type = type(result_type);
+ }
+
+ void name_analysis_visitor::visit(procedure_type_expression *type_expression)
+ {
+ std::shared_ptr result_type =
+ std::make_shared(std::move(build_procedure(*type_expression)));
+
+ this->current_type = type(result_type);
+ }
+
+ void name_analysis_visitor::visit(enumeration_type_expression *type_expression)
+ {
+ std::shared_ptr result_type = std::make_shared(type_expression->members);
+
+ this->current_type = type(result_type);
+ }
+
+ void name_analysis_visitor::visit(variable_declaration *declaration)
+ {
+ declaration->variable_type().accept(this);
+
+ for (const auto& variable_identifier : declaration->identifiers)
+ {
+ auto variable_symbol = std::make_shared(this->current_type, declaration->is_extern);
+
+ variable_symbol->exported = variable_identifier.exported;
+ if (!this->bag.enter(variable_identifier.name, variable_symbol))
+ {
+ add_error(variable_identifier.name, this->input_file,
+ declaration->position());
+ }
+ }
+ }
+
+ void name_analysis_visitor::visit(constant_declaration *definition)
+ {
+ definition->body().accept(this);
+ auto constant_symbol = std::make_shared(this->current_literal);
+
+ constant_symbol->exported = definition->identifier.exported;
+ this->bag.enter(definition->identifier.name, constant_symbol);
+ }
+
+ void name_analysis_visitor::visit(procedure_declaration *definition)
+ {
+ std::shared_ptr info;
+ auto heading = build_procedure(definition->heading());
+
+ if (definition->body.has_value())
+ {
+ info = std::make_shared(heading, definition->parameter_names, this->bag.enter());
+
+ for (constant_declaration *const constant : definition->body.value().constants())
+ {
+ constant->accept(this);
+ }
+ for (variable_declaration *const variable : definition->body.value().variables())
+ {
+ variable->accept(this);
+ }
+ for (statement *const statement : definition->body.value().body())
+ {
+ statement->accept(this);
+ }
+ this->bag.leave();
+ }
+ else
+ {
+ info = std::make_shared(heading, definition->parameter_names);
+ }
+ info->exported = definition->identifier.exported;
+ this->bag.enter(definition->identifier.name, info);
+ }
+
+ void name_analysis_visitor::visit(assign_statement *statement)
+ {
+ statement->lvalue().accept(this);
+ statement->rvalue().accept(this);
+ }
+
+ void name_analysis_visitor::visit(if_statement *statement)
+ {
+ statement->body().prerequisite().accept(this);
+ for (struct statement *const statement : statement->body().statements)
+ {
+ statement->accept(this);
+ }
+ for (const auto branch : statement->branches)
+ {
+ branch->prerequisite().accept(this);
+
+ for (struct statement *const statement : branch->statements)
+ {
+ statement->accept(this);
+ }
+ }
+ if (statement->alternative != nullptr)
+ {
+ for (struct statement *const statement : *statement->alternative)
+ {
+ statement->accept(this);
+ }
+ }
+ }
+
+ void name_analysis_visitor::visit(import_declaration *)
+ {
+ }
+
+ void name_analysis_visitor::visit(while_statement *statement)
+ {
+ statement->body().prerequisite().accept(this);
+ for (struct statement *const statement : statement->body().statements)
+ {
+ statement->accept(this);
+ }
+ for (const auto branch : statement->branches)
+ {
+ branch->prerequisite().accept(this);
+
+ for (struct statement *const statement : branch->statements)
+ {
+ statement->accept(this);
+ }
+ }
+ }
+
+ void name_analysis_visitor::visit(return_statement *statement)
+ {
+ statement->return_expression().accept(this);
+ }
+
+ void name_analysis_visitor::visit(defer_statement *statement)
+ {
+ for (struct statement *const statement : statement->statements)
+ {
+ statement->accept(this);
+ }
+ }
+
+ void name_analysis_visitor::visit(case_statement *statement)
+ {
+ statement->condition().accept(this);
+ for (const switch_case& case_block : statement->cases)
+ {
+ for (expression *const case_label : case_block.labels)
+ {
+ case_label->accept(this);
+ }
+ for (struct statement *const statement : case_block.statements)
+ {
+ statement->accept(this);
+ }
+ }
+ if (statement->alternative != nullptr)
+ {
+ for (struct statement *const statement : *statement->alternative)
+ {
+ statement->accept(this);
+ }
+ }
+ }
+
+ void name_analysis_visitor::visit(procedure_call *call)
+ {
+ call->callable().accept(this);
+ for (expression *const argument: call->arguments)
+ {
+ argument->accept(this);
+ }
+ }
+
+ void name_analysis_visitor::visit(unit *unit)
+ {
+ for (type_declaration *const type : unit->types)
+ {
+ type->accept(this);
+ }
+ for (variable_declaration *const variable : unit->variables)
+ {
+ variable->accept(this);
+ }
+ for (procedure_declaration *const procedure : unit->procedures)
+ {
+ procedure->accept(this);
+ }
+ }
+
+ void name_analysis_visitor::visit(traits_expression *trait)
+ {
+ if (!trait->parameters.empty())
+ {
+ trait->parameters.front()->accept(this);
+ trait->types.push_back(this->current_type);
+ }
+ }
+
+ void name_analysis_visitor::visit(cast_expression *expression)
+ {
+ expression->value().accept(this);
+ expression->target().accept(this);
+ expression->expression_type = this->current_type;
+ }
+
+ void name_analysis_visitor::visit(binary_expression *expression)
+ {
+ expression->lhs().accept(this);
+ expression->rhs().accept(this);
+ }
+
+ void name_analysis_visitor::visit(unary_expression *expression)
+ {
+ expression->operand().accept(this);
+ }
+
+ void name_analysis_visitor::visit(variable_expression *)
+ {
+ }
+
+ void name_analysis_visitor::visit(array_access_expression *expression)
+ {
+ expression->base().accept(this);
+ expression->index().accept(this);
+ }
+
+ void name_analysis_visitor::visit(field_access_expression *expression)
+ {
+ expression->base().accept(this);
+ }
+
+ void name_analysis_visitor::visit(dereference_expression *expression)
+ {
+ expression->base().accept(this);
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ void name_analysis_visitor::visit(literal *literal)
+ {
+ this->current_literal = literal->value;
+ }
+
+ declaration_visitor::declaration_visitor(const char *path)
+ : error_container(path)
+ {
+ }
+
+ void declaration_visitor::visit(program *program)
+ {
+ visit(static_cast(program));
+ }
+
+ void declaration_visitor::visit(import_declaration *)
+ {
+ }
+
+ void declaration_visitor::visit(unit *unit)
+ {
+ for (import_declaration *const _import : unit->imports)
+ {
+ _import->accept(this);
+ }
+ for (type_declaration *const type : unit->types)
+ {
+ type->accept(this);
+ }
+ for (variable_declaration *const variable : unit->variables)
+ {
+ variable->accept(this);
+ }
+ for (procedure_declaration *const procedure : unit->procedures)
+ {
+ procedure->accept(this);
+ }
+ }
+
+ void declaration_visitor::visit(type_declaration *definition)
+ {
+ const std::string& type_identifier = definition->identifier.name;
+
+ if (!this->unresolved.insert({ type_identifier, std::make_shared(type_identifier) }).second)
+ {
+ add_error(definition->identifier.name, this->input_file,
+ definition->position());
+ }
+ }
+
+ void declaration_visitor::visit(variable_declaration *declaration)
+ {
+ if (declaration->has_initializer() && declaration->identifiers.size() > 1)
+ {
+ add_error(this->input_file, declaration->position());
+ }
+ }
+
+ void declaration_visitor::visit(procedure_declaration *definition)
+ {
+ if (!definition->body.has_value())
+ {
+ return;
+ }
+ for (variable_declaration *const variable : definition->body.value().variables())
+ {
+ variable->accept(this);
+ }
+ }
+}
diff --git a/frontend/symbol.cc b/frontend/symbol.cc
new file mode 100644
index 0000000..bfecbd4
--- /dev/null
+++ b/frontend/symbol.cc
@@ -0,0 +1,427 @@
+/* Symbol definitions.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include "elna/frontend/symbol.h"
+
+namespace elna::frontend
+{
+ type::type()
+ {
+ }
+
+ type::type(std::shared_ptr alias)
+ : tag(type_tag::alias), alias(alias)
+ {
+ }
+
+ type::type(std::shared_ptr primitive)
+ : tag(type_tag::primitive), primitive(primitive)
+ {
+ }
+
+ type::type(std::shared_ptr record)
+ : tag(type_tag::record), record(record)
+ {
+ }
+
+ type::type(std::shared_ptr _union)
+ : tag(type_tag::_union), _union(_union)
+ {
+ }
+
+ type::type(std::shared_ptr pointer)
+ : tag(type_tag::pointer), pointer(pointer)
+ {
+ }
+
+ type::type(std::shared_ptr array)
+ : tag(type_tag::array), array(array)
+ {
+ }
+
+ type::type(std::shared_ptr procedure)
+ : tag(type_tag::procedure), procedure(procedure)
+ {
+ }
+
+ type::type(std::shared_ptr enumeration)
+ : tag(type_tag::enumeration), enumeration(enumeration)
+ {
+ }
+
+ void type::copy(const type& other)
+ {
+ switch (other.tag)
+ {
+ case type_tag::empty:
+ break;
+ case type_tag::alias:
+ new (&alias) std::weak_ptr(other.alias);
+ break;
+ case type_tag::primitive:
+ new (&primitive) std::shared_ptr(other.primitive);
+ break;
+ case type_tag::record:
+ new (&record) std::shared_ptr(other.record);
+ break;
+ case type_tag::_union:
+ new (&_union) std::shared_ptr(other._union);
+ break;
+ case type_tag::pointer:
+ new (&pointer) std::shared_ptr(other.pointer);
+ break;
+ case type_tag::array:
+ new (&array) std::shared_ptr(other.array);
+ break;
+ case type_tag::procedure:
+ new (&procedure) std::shared_ptr(other.procedure);
+ break;
+ case type_tag::enumeration:
+ new (&enumeration) std::shared_ptr(other.enumeration);
+ break;
+ }
+ }
+
+ type::type(const type& other)
+ : tag(other.tag)
+ {
+ copy(other);
+ }
+
+ void type::move(type&& other)
+ {
+ switch (other.tag)
+ {
+ case type_tag::empty:
+ break;
+ case type_tag::alias:
+ new (&alias) std::weak_ptr(std::move(other.alias));
+ break;
+ case type_tag::primitive:
+ new (&primitive) std::shared_ptr(std::move(other.primitive));
+ break;
+ case type_tag::record:
+ new (&record) std::shared_ptr(std::move(other.record));
+ break;
+ case type_tag::_union:
+ new (&_union) std::shared_ptr(std::move(other._union));
+ break;
+ case type_tag::pointer:
+ new (&pointer) std::shared_ptr(std::move(other.pointer));
+ break;
+ case type_tag::array:
+ new (&array) std::shared_ptr(std::move(other.array));
+ break;
+ case type_tag::procedure:
+ new (&procedure) std::shared_ptr(std::move(other.procedure));
+ break;
+ case type_tag::enumeration:
+ new (&enumeration) std::shared_ptr(std::move(other.enumeration));
+ break;
+ }
+ }
+
+ type& type::operator=(const type& other)
+ {
+ this->~type();
+ this->tag = other.tag;
+ copy(other);
+ return *this;
+ }
+
+ type::type(type&& other)
+ : tag(other.tag)
+ {
+ move(std::move(other));
+ }
+
+ type& type::operator=(type&& other)
+ {
+ this->~type();
+ this->tag = other.tag;
+ move(std::move(other));
+ return *this;
+ }
+
+ bool type::operator==(const std::nullptr_t&)
+ {
+ return empty();
+ }
+
+ type::~type()
+ {
+ switch (tag)
+ {
+ case type_tag::empty:
+ break;
+ case type_tag::alias:
+ this->alias.~weak_ptr();
+ break;
+ case type_tag::primitive:
+ this->primitive.~shared_ptr();
+ break;
+ case type_tag::record:
+ this->record.~shared_ptr();
+ break;
+ case type_tag::_union:
+ this->_union.~shared_ptr();
+ break;
+ case type_tag::pointer:
+ this->pointer.~shared_ptr();
+ break;
+ case type_tag::array:
+ this->array.~shared_ptr();
+ break;
+ case type_tag::procedure:
+ this->procedure.~shared_ptr();
+ break;
+ case type_tag::enumeration:
+ this->enumeration.~shared_ptr();
+ break;
+ }
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::alias ? this->alias.lock() : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::primitive ? this->primitive : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::record ? this->record : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::_union ? this->_union : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::pointer ? this->pointer : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::array ? this->array : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::procedure ? this->procedure : nullptr;
+ }
+
+ template<>
+ std::shared_ptr type::get() const
+ {
+ return tag == type_tag::enumeration ? this->enumeration : nullptr;
+ }
+
+ bool type::empty() const
+ {
+ return tag == type_tag::empty;
+ }
+
+ alias_type::alias_type(const std::string& name)
+ : name(name), reference()
+ {
+ }
+
+ pointer_type::pointer_type(type base)
+ : base(base)
+ {
+ }
+
+ array_type::array_type(type base, std::uint64_t size)
+ : base(base), size(size)
+ {
+ }
+
+ primitive_type::primitive_type(const std::string& identifier)
+ : identifier(identifier)
+ {
+ }
+
+ procedure_type::procedure_type(return_t return_type)
+ : return_type(return_type)
+ {
+ }
+
+ enumeration_type::enumeration_type(const std::vector& members)
+ : members(members)
+ {
+ }
+
+ info::~info()
+ {
+ }
+
+ std::shared_ptr info::is_type()
+ {
+ return nullptr;
+ }
+
+ std::shared_ptr info::is_procedure()
+ {
+ return nullptr;
+ }
+
+ std::shared_ptr info::is_constant()
+ {
+ return nullptr;
+ }
+
+ std::shared_ptr info::is_variable()
+ {
+ return nullptr;
+ }
+
+ type_info::type_info(const type symbol)
+ : symbol(symbol)
+ {
+ }
+
+ std::shared_ptr type_info::is_type()
+ {
+ return std::static_pointer_cast(shared_from_this());
+ }
+
+ procedure_info::procedure_info(const procedure_type symbol, const std::vector names,
+ std::shared_ptr scope)
+ : symbol(symbol), names(names), scope(scope)
+ {
+ }
+
+ std::shared_ptr procedure_info::is_procedure()
+ {
+ return std::static_pointer_cast(shared_from_this());
+ }
+
+ bool procedure_info::is_extern() const
+ {
+ return this->scope == nullptr;
+ }
+
+ constant_info::constant_info(const variant& symbol)
+ : symbol(symbol)
+ {
+ }
+
+ std::shared_ptr constant_info::is_constant()
+ {
+ return std::static_pointer_cast(shared_from_this());
+ }
+
+ variable_info::variable_info(const type symbol, bool is_extern)
+ : symbol(symbol), is_extern(is_extern)
+ {
+ }
+
+ std::shared_ptr variable_info::is_variable()
+ {
+ return std::static_pointer_cast(shared_from_this());
+ }
+
+ std::shared_ptr builtin_symbol_table()
+ {
+ auto result = std::make_shared();
+
+ result->enter("Int", std::make_shared(type(std::make_shared("Int"))));
+ result->enter("Word", std::make_shared(type(std::make_shared("Word"))));
+ result->enter("Char", std::make_shared(type(std::make_shared("Char"))));
+ result->enter("Bool", std::make_shared(type(std::make_shared("Bool"))));
+ result->enter("Pointer", std::make_shared(type(std::make_shared("Pointer"))));
+ result->enter("Float", std::make_shared(type(std::make_shared("Float"))));
+ result->enter("String", std::make_shared(type(std::make_shared("String"))));
+
+ return result;
+ }
+
+ symbol_bag::symbol_bag(forward_table&& unresolved, std::shared_ptr global_table)
+ : unresolved(unresolved)
+ {
+ this->symbols = std::make_shared(global_table);
+ }
+
+ std::shared_ptr symbol_bag::lookup(const std::string& name)
+ {
+ for (auto import_bag : this->imports)
+ {
+ if (auto result = import_bag->lookup(name))
+ {
+ return result;
+ }
+ }
+ return this->symbols->lookup(name);
+ }
+
+ bool symbol_bag::enter(const std::string& name, std::shared_ptr entry)
+ {
+ return this->symbols->enter(name, entry);
+ }
+
+ std::shared_ptr symbol_bag::enter()
+ {
+ this->symbols = std::make_shared(this->symbols);
+ return this->symbols;
+ }
+
+ void symbol_bag::enter(std::shared_ptr child)
+ {
+ this->symbols = child;
+ }
+
+ std::shared_ptr symbol_bag::leave()
+ {
+ std::shared_ptr result = this->symbols;
+
+ this->symbols = result->scope();
+ return result;
+ }
+
+ std::shared_ptr symbol_bag::declared(const std::string& symbol_name)
+ {
+ auto unresolved_alias = this->unresolved.find(symbol_name);
+
+ return unresolved_alias == this->unresolved.end() ? std::shared_ptr() : unresolved_alias->second;
+ }
+
+ std::shared_ptr symbol_bag::resolve(const std::string& symbol_name, type& resolution)
+ {
+ auto unresolved_declaration = this->unresolved.at(symbol_name);
+
+ unresolved_declaration->reference = resolution;
+ return unresolved_declaration;
+ }
+
+ void symbol_bag::add_import(const symbol_bag& bag)
+ {
+ this->imports.push_front(bag.symbols);
+ }
+}
diff --git a/gcc/Make-lang.in b/gcc/Make-lang.in
new file mode 100644
index 0000000..e25fc6d
--- /dev/null
+++ b/gcc/Make-lang.in
@@ -0,0 +1,174 @@
+# Top level -*- makefile -*- fragment for the Elna frontend.
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# .
+
+ELNA_INSTALL_NAME := $(shell echo gelna|sed '$(program_transform_name)')
+ELNA_TARGET_INSTALL_NAME := $(target_noncanonical)-$(shell echo gelna|sed '$(program_transform_name)')
+
+elna: elna1$(exeext)
+
+.PHONY: elna
+
+# Driver
+
+ELNA_OBJS = \
+ $(GCC_OBJS) \
+ elna/elna-spec.o \
+ $(END)
+
+gelna$(exeext): $(ELNA_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a $(LIBDEPS)
+ +$(LINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
+ $(ELNA_OBJS) $(EXTRA_GCC_OBJS) libcommon-target.a \
+ $(EXTRA_GCC_LIBS) $(LIBS)
+
+# Create a version of the gelna driver which calls the cross-compiler.
+gelna-cross$(exeext): gelna$(exeext)
+ -rm -f gelna-cross$(exeext)
+ cp gelna$(exeext) gelna-cross$(exeext)
+
+# The compiler proper
+
+elna_OBJS = \
+ elna/elna1.o \
+ elna/elna-generic.o \
+ elna/elna-diagnostic.o \
+ elna/elna-tree.o \
+ elna/elna-builtins.o \
+ elna/ast.o \
+ elna/dependency.o \
+ elna/driver.o \
+ elna/lexer.o \
+ elna/parser.o \
+ elna/semantic.o \
+ elna/symbol.o \
+ elna/result.o \
+ $(END)
+
+elna1$(exeext): attribs.o $(elna_OBJS) $(BACKEND) $(LIBDEPS)
+ +$(LLINKER) $(ALL_LINKERFLAGS) $(LDFLAGS) -o $@ \
+ attribs.o $(elna_OBJS) $(BACKEND) $(LIBS) $(BACKENDLIBS)
+
+elna.all.cross: gelna-cross$(exeext)
+
+elna.start.encap: gelna$(exeext)
+elna.rest.encap:
+
+# No elna-specific selftests.
+selftest-elna:
+
+ELNA_TEXI_FILES = \
+ elna/gcc/gelna.texi \
+ $(srcdir)/doc/include/fdl.texi \
+ $(srcdir)/doc/include/gpl_v3.texi \
+ $(srcdir)/doc/include/funding.texi \
+ $(srcdir)/doc/include/gcc-common.texi \
+ gcc-vers.texi
+
+elna.install-common: installdirs
+ -rm -f $(DESTDIR)$(bindir)/$(ELNA_INSTALL_NAME)$(exeext)
+ $(INSTALL_PROGRAM) gelna$(exeext) $(DESTDIR)$(bindir)/$(ELNA_INSTALL_NAME)$(exeext)
+ -if test -f elna1$(exeext); then \
+ if test -f gelna-cross$(exeext); then \
+ :; \
+ else \
+ rm -f $(DESTDIR)$(bindir)/$(ELNA_TARGET_INSTALL_NAME)$(exeext); \
+ ( cd $(DESTDIR)$(bindir) && \
+ $(LN) $(ELNA_INSTALL_NAME)$(exeext) $(ELNA_TARGET_INSTALL_NAME)$(exeext) ); \
+ fi; \
+ fi
+
+$(build_htmldir)/gelna/index.html: $(ELNA_TEXI_FILES)
+ $(mkinstalldirs) $(@D)
+ rm -f $(@D)/*
+ $(TEXI2HTML) -I $(gcc_docdir)/include -I $(srcdir)/elna -o $(@D) $<
+
+# Required goals, they still do nothing
+elna.install-man:
+elna.install-info:
+elna.install-pdf:
+elna.install-plugin:
+
+elna.install-html: $(build_htmldir)/gelna
+ @$(NORMAL_INSTALL)
+ test -z "$(htmldir)" || $(mkinstalldirs) "$(DESTDIR)$(htmldir)"
+ @for p in $(build_htmldir)/gelna; do \
+ if test -f "$$p" || test -d "$$p"; then d=""; else d="$(srcdir)/"; fi; \
+ f=$(html__strip_dir) \
+ if test -d "$$d$$p"; then \
+ echo " $(mkinstalldirs) '$(DESTDIR)$(htmldir)/$$f'"; \
+ $(mkinstalldirs) "$(DESTDIR)$(htmldir)/$$f" || exit 1; \
+ echo " $(INSTALL_DATA) '$$d$$p'/* '$(DESTDIR)$(htmldir)/$$f'"; \
+ $(INSTALL_DATA) "$$d$$p"/* "$(DESTDIR)$(htmldir)/$$f"; \
+ else \
+ echo " $(INSTALL_DATA) '$$d$$p' '$(DESTDIR)$(htmldir)/$$f'"; \
+ $(INSTALL_DATA) "$$d$$p" "$(DESTDIR)$(htmldir)/$$f"; \
+ fi; \
+ done
+
+elna.info:
+elna.dvi:
+elna.pdf:
+elna.html: $(build_htmldir)/gelna/index.html
+elna.man:
+elna.mostlyclean:
+elna.clean:
+elna.distclean:
+elna.maintainer-clean:
+
+# make uninstall
+elna.uninstall:
+ -rm -f gelna$(exeext) elna1$(exeext)
+ -rm -f $(elna_OBJS)
+
+# Used for handling bootstrap
+elna.stage1: stage1-start
+ -mv elna/*$(objext) stage1/elna
+elna.stage2: stage2-start
+ -mv elna/*$(objext) stage2/elna
+elna.stage3: stage3-start
+ -mv elna/*$(objext) stage3/elna
+elna.stage4: stage4-start
+ -mv elna/*$(objext) stage4/elna
+elna.stageprofile: stageprofile-start
+ -mv elna/*$(objext) stageprofile/elna
+elna.stagefeedback: stagefeedback-start
+ -mv elna/*$(objext) stagefeedback/elna
+
+ELNA_INCLUDES = -I $(srcdir)/elna/include -I elna/generated
+ELNA_CXXFLAGS = -std=c++17
+
+elna/%.o: elna/frontend/%.cc elna/generated/parser.hh elna/generated/location.hh
+ $(COMPILE) $(ELNA_CXXFLAGS) $(ELNA_INCLUDES) $<
+ $(POSTCOMPILE)
+
+elna/%.o: elna/generated/%.cc elna/generated/parser.hh elna/generated/location.hh
+ $(COMPILE) $(ELNA_CXXFLAGS) $(ELNA_INCLUDES) $<
+ $(POSTCOMPILE)
+
+elna/%.o: elna/gcc/%.cc elna/generated/parser.hh elna/generated/location.hh
+ $(COMPILE) $(ELNA_CXXFLAGS) $(ELNA_INCLUDES) $<
+ $(POSTCOMPILE)
+
+elna/generated/parser.cc: elna/frontend/parser.yy
+ mkdir -p $(dir $@)
+ $(BISON) -d -o $@ $<
+
+elna/generated/parser.hh elna/generated/location.hh: elna/generated/parser.cc
+ @touch $@
+
+elna/generated/lexer.cc: elna/frontend/lexer.ll
+ mkdir -p $(dir $@)
+ $(FLEX) -o $@ $<
diff --git a/gcc/README.md b/gcc/README.md
new file mode 100644
index 0000000..99d03c3
--- /dev/null
+++ b/gcc/README.md
@@ -0,0 +1,42 @@
+# Elna programming language
+
+## Current implementation
+
+This repository contains a GCC frontend for Elna. After finishing the frontend
+I'm planning to rewrite the compiler in Elna itself with its own backend and
+a hand-written parser. So GCC gives a way to have a simple bootstrap compiler
+and a possbility to compile Elna programs for different platforms.
+
+## Grammar
+
+Flex and bison grammar specifications, `lexer.ll` and `parser.yy`, can be found
+in the `boot/` directory.
+
+## Build
+
+The frontend requires GCC 15.2.0 (not tested with other versions).
+
+Download the GCC source. Copy the contents of this repository into `gcc/elna`
+inside GCC. Finally build GCC enabling the frontend with
+`--enable-languages=c,c++,elna`. After the installation the compiler can be
+invoked with `$prefix/bin/gelna`.
+
+There is also a `Rakefile` that downloads, builds and installs GCC into the
+`./build/` subdirectory. The `Rakefile` assumes that ruby and rake, as well as
+all GCC dependencies are already available in the system. It works under Linux
+and Mac OS. In the latter case GCC is patched with the patches used by Homebrew
+(official GCC doesn't support Apple silicon targets). Invoke with
+
+```sh
+rake boot
+```
+
+`gcc` binary is used by default, but a different gcc version can be specified
+by passing `CC` and `CXX` environment variables to rake, e.g.:
+
+```sh
+rake CC=gcc-15 CXX=g++-15 boot
+```
+
+See `rake -T` for more tasks. The GCC source is under `build/tools`. The
+installation path is `build/host/install`.
diff --git a/gcc/config-lang.in b/gcc/config-lang.in
new file mode 100644
index 0000000..0cbbe1f
--- /dev/null
+++ b/gcc/config-lang.in
@@ -0,0 +1,37 @@
+# Top level configure fragment for gcc Elna frontend.
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# GCC is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+
+# GCC is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3. If not see
+# .
+
+# Configure looks for the existence of this file to auto-config each language.
+# We define several parameters used by configure:
+#
+# language - name of language as it would appear in $(LANGUAGES)
+# boot_language - "yes" if we need to build this language in stage1
+# compilers - value to add to $(COMPILERS)
+
+language="elna"
+gcc_subdir="elna/gcc"
+
+compilers="elna1\$(exeext)"
+
+target_libs=""
+
+gtfiles="\$(srcdir)/elna/gcc/elna1.cc \$(srcdir)/elna/include/elna/gcc/elna1.h"
+
+lang_requires_boot_languages=c++
+
+# Do not build by default
+build_by_default="no"
diff --git a/gcc/elna-builtins.cc b/gcc/elna-builtins.cc
new file mode 100644
index 0000000..cf06df8
--- /dev/null
+++ b/gcc/elna-builtins.cc
@@ -0,0 +1,274 @@
+/* Builtin definitions.
+ Copyright (C) 2025 Free Software Foundation, Inc.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+. */
+
+#include
+
+#include "elna/gcc/elna-builtins.h"
+#include "elna/gcc/elna1.h"
+#include "stor-layout.h"
+#include "stringpool.h"
+#include "elna/gcc/elna-tree.h"
+
+namespace elna::gcc
+{
+ void init_ttree()
+ {
+ elna_int_type_node = long_integer_type_node;
+ elna_word_type_node = size_type_node;
+ elna_char_type_node = unsigned_char_type_node;
+ elna_pointer_type_node = ptr_type_node;
+ elna_float_type_node = double_type_node;
+
+ elna_bool_type_node = boolean_type_node;
+ elna_bool_true_node = boolean_true_node;
+ elna_bool_false_node = boolean_false_node;
+
+ elna_pointer_nil_node = null_pointer_node;
+
+ elna_string_type_node = make_node(RECORD_TYPE);
+ tree string_ptr_type = build_pointer_type_for_mode(elna_char_type_node, VOIDmode, true);
+
+ elna_string_length_field_node = build_field(UNKNOWN_LOCATION,
+ elna_string_type_node, "length", build_qualified_type(elna_word_type_node, TYPE_QUAL_CONST));
+ elna_string_ptr_field_node = build_field(UNKNOWN_LOCATION,
+ elna_string_type_node, "ptr", build_qualified_type(string_ptr_type, TYPE_QUAL_CONST));
+
+ TYPE_FIELDS(elna_string_type_node) = chainon(elna_string_ptr_field_node, elna_string_length_field_node);
+ layout_type(elna_string_type_node);
+ }
+
+ static
+ tree declare_builtin_type(std::shared_ptr symbol_table, const char *name, tree type)
+ {
+ tree identifier = get_identifier(name);
+ tree type_declaration = build_decl(UNKNOWN_LOCATION, TYPE_DECL, identifier, type);
+
+ symbol_table->enter(name, type_declaration);
+
+ return type_declaration;
+ }
+
+ std::shared_ptr builtin_symbol_table()
+ {
+ std::shared_ptr symbol_table = std::make_shared