PiperOrigin-RevId: 172480513

1 files changed, 77 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/config/ConfigRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/config/ConfigRuleClasses.java
index 6d6701f35b..7ba3611dad 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/config/ConfigRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/config/ConfigRuleClasses.java
@@ -228,6 +228,54 @@ public class ConfigRuleClasses {
                   .allowedFileTypes()
                   .mandatoryProviders(ImmutableList.of(ConfigFeatureFlagProvider.id()))
                   .nonconfigurable(NONCONFIGURABLE_ATTRIBUTE_REASON))
+          /* <!-- #BLAZE_RULE(config_setting).ATTRIBUTE(constraint_values) -->
+          The set of <code>constraint_values</code> that match this rule.
+
+          <p>A <a href="platform.html#constraint_value">constraint_value</a> is composed of a name
+          and a corresponding <a href="platform.html#constraint_setting">constraint_setting</a>
+          which classifies the value. A <a href=""platform.html#platform>platform</a> consists of a
+          collection of <code>constraint_value</code> labels which describes target itself and/or
+          how its environment.
+          </p>
+
+          <pre class="code">
+            constraint_setting(name = "rock_type")
+            constraint_value(name = metamorphic, constraint_setting = "rock_type")
+            platform(
+              name = "my_platform_rocks",
+              constraint_values = [":metamorphic"]
+            )
+          </pre>
+
+          <p>As mentioned above, this rule inherits the configuration of the configured target that
+            references it in a <code>select</code> statement. This <code>constraint_values</code>
+            attribute is considered to "match" a Blaze invocation if it includes each
+            <code>constraint_value</code> specified in the configuration's target platform which is
+            set with the command line flag <code>--experimental_platforms</code>. If it contains
+            extra <code>constraint_values</code> not included in the target platform, it is still
+            considered a match. In this example, both <code>slate</code> and
+            <code>marble</code> would be considered matches for a blaze invocation which
+            uses <code>--experimental_platforms=my_platform_rocks</code>. Multiple matches like this
+            may lead to ambiguous select resolves and are not allowed.
+          </p>
+          <pre class = "code">
+            constraint_setting(name = "color")
+            constraint_value(name = "white", constraint_setting = "color")
+
+            config_setting(
+              name = "slate",
+              constraint_values = [":metamorphic"]
+            )
+
+            config_setting(
+              name = "marble",
+              constraint_values = [
+                ":metamorphic",
+                ":white"
+              ]
+            )
+          </pre>
+          <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
           .add(
               attr(CONSTRAINT_VALUES_ATTRIBUTE, LABEL_LIST)
                   .nonconfigurable(NONCONFIGURABLE_ATTRIBUTE_REASON)
@@ -292,6 +340,28 @@ config_setting(
 )
 </pre>
 
+<p>The following config_setting matches any Blaze invocation that builds a platform which contains
+  exactly the same or a subset of its constraint_values (like the example below).
+</p>
+
+<pre class=""code">
+config_setting(
+    name = "marble",
+    constraint_values = [
+        "white",
+        "metamorphic",
+    ]
+)
+
+platform(
+    name = "marble_platform",
+    constraint_values = [
+        "white",
+        "metamorphic"
+    ]
+)
+</pre>
+
 <h4 id="config_setting_notes">Notes</h4>
 
 <p>See <a href="${link select}">select</a> for policies on what happens depending on how
@@ -316,6 +386,13 @@ config_setting(
   same thing.
 </p>
 
+<p><a href="general.html#config_setting.values"><code>values</code></a>,
+   <a href="general.html#config_setting.define_values"><code>define_values</code></a>, and
+   <a href=general.html#config_setting.constraint_values"><code>constraint_values</code></a>
+   can be used in any combination in the same config_setting but at least one must be set for any
+   given config_setting.
+</p>
+
 <!-- #END_BLAZE_RULE -->*/
 
   /** Rule definition for Android's config_feature_flag rule. */