commit c13bb39f78de5e016c9ec1e3e20c43a92ea7d159
author dslomov <dslomov@google.com> Wed Aug 02 23:29:54 2017 +0200
committer Dmitry Lomov <dslomov@google.com> Thu Aug 03 12:10:00 2017 +0200
tree 2b66f2ef9fb463f4ef71e3ae2feeaafb59886054
parent 20f7da51b3228eca561102e3b871b67b704347a9

Use RequiredProviders to validate rule prerequisites in RuleContext.

We now use a unified way to check provider requirements everywhere.

Reland of https://github.com/bazelbuild/bazel/commit/c32e1b1efcd703b3780de47fba62974123593d71.

RELNOTES: None.
PiperOrigin-RevId: 164038621

src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
index b174a47..b3b4894 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/TransitiveInfoCollection.java
@@ -16,6 +16,7 @@
 
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.packages.RequiredProviders;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkModuleCategory;
 import com.google.devtools.build.lib.syntax.SkylarkIndexable;
@@ -79,4 +80,25 @@
    * <b>null</b>.</p>
    */
   @Nullable BuildConfiguration getConfiguration();
+
+  /**
+   * Checks whether this {@link TransitiveInfoCollection} satisfies given {@link RequiredProviders}.
+   */
+  default boolean satisfies(RequiredProviders providers) {
+    return providers.isSatisfiedBy(
+        aClass -> getProvider(aClass.asSubclass(TransitiveInfoProvider.class)) != null,
+        id -> this.get(id) != null);
+  }
+
+  /**
+   * Returns providers that this {@link TransitiveInfoCollection} misses from a given {@link
+   * RequiredProviders}.
+   *
+   * <p>If none are missing, returns {@link RequiredProviders} that accept any set of providers.
+   */
+  default RequiredProviders missingProviders(RequiredProviders providers) {
+    return providers.getMissing(
+        aClass -> getProvider(aClass.asSubclass(TransitiveInfoProvider.class)) != null,
+        id -> this.get(id) != null);
+  }
 }