docs/versions/8.4.0/rules/lib/toplevel/config.mdx
{% dynamic setvar source_file "src/main/java/com/google/devtools/build/lib/starlarkbuildapi/config/StarlarkConfigApi.java" %} {% dynamic setvar version "8.4.0" %} {% dynamic setvar original_path "/rules/lib/toplevel/config" %} {% include "_buttons.html" %}
<!-- {% raw %} -->This is a top-level module for creating configuration transitions and build setting descriptors which describe what kind of build setting (if any) a rule is. <p>ex: the following rule is marked as a build setting by setting the <code>build_setting</code> parameter of the <code>rule()</code> function. Specifically it is a build setting of type <code>int</code> and is a <code>flag</code> which means this build setting is callable on the command line.
<pre class=language-python> my_rule = rule( implementation = _impl, build_setting = config.int(flag = True), ... )</pre> <h2>Members</h2> <ul> <li> <a href="#bool">bool</a> </li> <li> <a href="#exec">exec</a> </li> <li> <a href="#int">int</a> </li> <li> <a href="#none">none</a> </li> <li> <a href="#string">string</a> </li> <li> <a href="#string_list">string_list</a> </li> <li> <a href="#target">target</a> </li> </ul> <h2 id="bool">bool</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/BuildSetting.html">BuildSetting</a> config.bool(flag=False)</pre></p>
A bool-typed build setting
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<h3 class="hide-from-toc">Parameters</h3>
<table class="table table-bordered table-condensed table-params">
<colgroup>
<col class="col-param">
<col class="param-description">
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<th>Parameter</th>
<th>Description</th>
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<td id="bool.flag">
<code>flag</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
Whether or not this build setting is callable on the command line.
</td>
</tr>
</tbody>
</table>
<h2 id="exec">exec</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/ExecTransitionFactory.html">ExecTransitionFactory</a> config.exec(exec_group=None)</pre></p>
Creates an execution transition.
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<h3 class="hide-from-toc">Parameters</h3>
<table class="table table-bordered table-condensed table-params">
<colgroup>
<col class="col-param">
<col class="param-description">
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<thead>
<tr>
<th>Parameter</th>
<th>Description</th>
</tr>
</thead>
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<tr>
<td id="exec.exec_group">
<code>exec_group</code>
</td>
<td>
<a class="anchor" href="../core/string.html">string</a>; or <code>None</code>;
default is <code>None</code>
The name of the exec group whose execution platform this transition will use. If not provided, this exec transition will use the target's default execution platform.
</td>
</tr>
</tbody>
</table>
<h2 id="int">int</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/BuildSetting.html">BuildSetting</a> config.int(flag=False)</pre></p>
An integer-typed build setting
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<h3 class="hide-from-toc">Parameters</h3>
<table class="table table-bordered table-condensed table-params">
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<th>Parameter</th>
<th>Description</th>
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<td id="int.flag">
<code>flag</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
Whether or not this build setting is callable on the command line.
</td>
</tr>
</tbody>
</table>
<h2 id="none">none</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/transition.html">transition</a> config.none()</pre></p>
Creates a transition which removes all configuration, unsetting all flags. Intended for the case where a dependency is data-only and contains no code that needs to be built, but should only be analyzed once.
<h2 id="string">string</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/BuildSetting.html">BuildSetting</a> config.string(flag=False, allow_multiple=False)</pre></p>
A string-typed build setting
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<h3 class="hide-from-toc">Parameters</h3>
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<th>Parameter</th>
<th>Description</th>
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<td id="string.flag">
<code>flag</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
Whether or not this build setting is callable on the command line.
</td>
</tr>
<tr>
<td id="string.allow_multiple">
<code>allow_multiple</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
Deprecated, use a <code>string_list</code> setting with <code>repeatable = True</code> instead. If set, this flag is allowed to be set multiple times on the command line. The Value of the flag as accessed in transitions and build setting implementation function will be a list of strings. Insertion order and repeated values are both maintained. This list can be post-processed in the build setting implementation function if different behavior is desired.
</td>
</tr>
</tbody>
</table>
<h2 id="string_list">string_list</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/BuildSetting.html">BuildSetting</a> config.string_list(flag=False, repeatable=False)</pre></p>
A string list-typed build setting. On the command line pass a list using comma-separated value like <code>--//my/setting=foo,bar</code>.
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<h3 class="hide-from-toc">Parameters</h3>
<table class="table table-bordered table-condensed table-params">
<colgroup>
<col class="col-param">
<col class="param-description">
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<thead>
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<th>Parameter</th>
<th>Description</th>
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<td id="string_list.flag">
<code>flag</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
Whether or not this build setting is callable on the command line.
</td>
</tr>
<tr>
<td id="string_list.repeatable">
<code>repeatable</code>
</td>
<td>
<a class="anchor" href="../core/bool.html">bool</a>;
default is <code>False</code>
If set, instead of expecting a comma-separated value, this flag is allowed to be set multiple times on the command line with each individual value treated as a single string to add to the list value. Insertion order and repeated values are both maintained. This list can be post-processed in the build setting implementation function if different behavior is desired.
</td>
</tr>
</tbody>
</table>
<h2 id="target">target</h2>
<p><pre class="rule-signature"><a class="anchor" href="../builtins/transition.html">transition</a> config.target()</pre></p>
Creates a target transition. This is a no-op transition intended for the case where a transition object is needed, but doesn't want to actually change anything. Equivalent to <code>cfg = "target"</code> in <code>attr.label()</code>.