| # |
| # Copyright (C) 2020 Codethink Limited |
| # |
| # This program is free software; you can redistribute it and/or |
| # modify it under the terms of the GNU Lesser General Public |
| # License as published by the Free Software Foundation; either |
| # version 2 of the License, or (at your option) any later version. |
| # |
| # This library 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 |
| # Lesser General Public License for more details. |
| # |
| # You should have received a copy of the GNU Lesser General Public |
| # License along with this library. If not, see <http://www.gnu.org/licenses/>. |
| # |
| # Authors: |
| # Tristan van Berkom <tristan.vanberkom@codethink.co.uk> |
| |
| """ |
| link - Link elements |
| ================================ |
| This element is a link to another element, allowing one to create |
| a symbolic element which will be resolved to another element. |
| |
| |
| Overview |
| -------- |
| The only configuration allowed in a ``link`` element is the specified |
| target :ref:`element name <format_element_names>` of the link. |
| |
| .. code:: yaml |
| |
| kind: link |
| |
| config: |
| target: element.bst |
| |
| The ``link`` element can be used to refer to elements in subprojects, and |
| can be used to symbolically link :mod:`junction <elements.junction>` elements |
| as well as other elements. |
| """ |
| |
| from buildstream import Element |
| |
| |
| # Element implementation for the 'link' kind. |
| class LinkElement(Element): |
| # pylint: disable=attribute-defined-outside-init |
| |
| BST_MIN_VERSION = "2.0" |
| |
| # Links are not allowed any dependencies or sources |
| BST_FORBID_BDEPENDS = True |
| BST_FORBID_RDEPENDS = True |
| BST_FORBID_SOURCES = True |
| |
| def configure(self, node): |
| |
| node.validate_keys(["target"]) |
| |
| # Hold onto the node, keep it around for provenance. |
| # |
| self.target_node = node.get_scalar("target") |
| |
| def preflight(self): |
| pass |
| |
| def get_unique_key(self): |
| # This is only used early on but later discarded |
| return 1 |
| |
| def configure_sandbox(self, sandbox): |
| assert False, "link elements should be discarded at load time" |
| |
| def stage(self, sandbox): |
| assert False, "link elements should be discarded at load time" |
| |
| def generate_script(self): |
| assert False, "link elements should be discarded at load time" |
| |
| def assemble(self, sandbox): |
| assert False, "link elements should be discarded at load time" |
| |
| |
| # Plugin entry point |
| def setup(): |
| return LinkElement |