..
   This file is part of Logtalk <https://logtalk.org/>  
   Copyright 1998-2020 Paulo Moura <pmoura@logtalk.org>

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.


.. index:: pair: logtalk_compile/2; Built-in predicate
.. _predicates_logtalk_compile_2:

logtalk_compile/2
=================

Description
-----------

::

   logtalk_compile(File, Flags)
   logtalk_compile(Files, Flags)

Compiles to disk a :term:`source file` or a list of source files using a
list of compiler flags. The Logtalk source file name extension (by default,
``.lgt``) can be omitted. Source file paths can be absolute, relative to
the current directory, or use :term:`library notation`. This predicate can
also be used to compile Prolog source files as Logtalk source code. When no
recognized Logtalk or Prolog extension is specified, the compiler tries
first to append a Logtalk source file extension and then a Prolog source
file extension. If that fails, the compiler tries to use the file name
as-is. Compiler flags are represented as *flag(value)*. For a description
of the available compiler flags, please see the :ref:`programming_flags`
section in the User Manual. The recognized Logtalk and Prolog file
extensions are defined in the :term:`backend adapter files <adapter file>`.

When this predicate is called from the top-level interpreter, relative source
file paths are resolved using the current working directory. When the calls
are made from a source file, relative source file paths are resolved by
default using the source file directory (unless a
:ref:`relative_to <flag_relative_to>` flag is passed).

Note that only the errors related to problems in the predicate argument
are listed below. This predicate fails on the first error found during
compilation of a source file. In this case, no file with the compiled
code is written to disk.

.. warning::

   The compiler flags specified in the second argument only apply to the
   files listed in the first argument. Notably, if you are compiling a
   :term:`loader file`, the flags only apply to the loader file itself.

Modes and number of proofs
--------------------------

::

   logtalk_compile(@source_file_name, @list(compiler_flag)) - zero_or_one
   logtalk_compile(@list(source_file_name), @list(compiler_flag)) - zero_or_one

Errors
------

| ``File`` is a variable:
|     ``instantiation_error``
| ``Files`` is a variable or a list with an element which is a variable:
|     ``instantiation_error``
| ``File``, or an element ``File`` of the ``Files`` list, is neither a variable nor a source file name:
|     ``type_error(source_file_name, File)``
| ``File``, or an element ``File`` of the ``Files`` list, uses library notation but the library does not exist:
|     ``existence_error(library, Library)``
| ``File`` or an element ``File`` of the ``Files`` list, does not exist:
|     ``existence_error(file, File)``
|
| ``Flags`` is a variable or a list with an element which is a variable:
|     ``instantiation_error``
| ``Flags`` is neither a variable nor a proper list:
|     ``type_error(list, Flags)``
| An element ``Flag`` of the ``Flags`` list is not a valid compiler flag:
|     ``type_error(compiler_flag, Flag)``
| An element ``Flag`` of the ``Flags`` list defines a value for a read-only compiler flag:
|     ``permission_error(modify, flag, Flag)``
| An element ``Flag`` of the ``Flags`` list defines an invalid value for a flag:
|     ``domain_error(flag_value, Flag+Value)``

Examples
--------

::

   % compile to disk the "list" source file in the
   % current directory using default compiler flags:
   | ?- logtalk_compile(list, []).

   % compile to disk the "tree" source file in the "types"
   % library directory with the source_data flag turned on:
   | ?- logtalk_compile(types(tree), [source_data(on)]).

   % compile to disk the "file_system" source file in the
   % current directory with portability warnings suppressed:
   | ?- logtalk_compile(file_system, [portability(silent)]).

.. seealso::

   :ref:`predicates_logtalk_compile_1`,
   :ref:`predicates_logtalk_load_1`,
   :ref:`predicates_logtalk_load_2`,
   :ref:`predicates_logtalk_make_0`,
   :ref:`predicates_logtalk_make_1`,
   :ref:`predicates_logtalk_library_path_2`
