Better error message for experimental_objc_library targets built with a

crosstool that does not support objc.

--
MOS_MIGRATED_REVID=139598484

3 files changed, 23 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainFeatures.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainFeatures.java
index b3f325087b..694f4e6e53 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainFeatures.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcToolchainFeatures.java
@@ -1425,7 +1425,7 @@ public class CcToolchainFeatures implements Serializable {
     }
 
     /** @return whether an action config for the blaze action with the given name is enabled. */
-    boolean actionIsConfigured(String actionName) {
+    public boolean actionIsConfigured(String actionName) {
       return enabledActionConfigActionNames.contains(actionName);
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
index 3e529993c2..21d7cd3849 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CrosstoolCompilationSupport.java
@@ -60,7 +60,7 @@ public class CrosstoolCompilationSupport extends CompilationSupport {
 
   private static final String OBJC_MODULE_FEATURE_NAME = "use_objc_modules";
   private static final String NO_ENABLE_MODULES_FEATURE_NAME = "no_enable_modules";
-  private static final Iterable<String> ACTIVATED_ACTIONS =
+  private static final ImmutableList<String> ACTIVATED_ACTIONS =
       ImmutableList.of(
           "objc-compile",
           "objc++-compile",
@@ -221,6 +221,25 @@ public class CrosstoolCompilationSupport extends CompilationSupport {
     return this;
   }
 
+  @Override
+  CompilationSupport validateAttributes() throws RuleErrorException {
+    super.validateAttributes();
+
+    FeatureConfiguration featureConfiguration = ruleContext
+        .getPrerequisite(":cc_toolchain", Mode.TARGET)
+        .getProvider(CcToolchainProvider.class)
+        .getFeatures()
+        .getFeatureConfiguration(ACTIVATED_ACTIONS);
+    for (String action : ACTIVATED_ACTIONS) {
+      if (!featureConfiguration.actionIsConfigured(action)) {
+        ruleContext.ruleError(
+            String.format("Toolchain derived from CROSSTOOL for this build does not support objc."
+                + " Missing action %s.", action));
+      }
+    }
+    return this;
+  }
+
   private CcLibraryHelper createCcLibraryHelper(ObjcCommon common, VariablesExtension extension) {
     PrecompiledFiles precompiledFiles = new PrecompiledFiles(ruleContext);
     Collection<Artifact> arcSources = Sets.newHashSet(compilationArtifacts.getSrcs());
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java
index b58e842312..4ba890cb30 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ExperimentalObjcLibrary.java
@@ -44,11 +44,12 @@ public class ExperimentalObjcLibrary implements RuleConfiguredTargetFactory {
   public static ConfiguredTarget configureExperimentalObjcLibrary(RuleContext ruleContext)
       throws InterruptedException, RuleErrorException {
     validateAttributes(ruleContext);
-
+    
     ObjcCommon common = common(ruleContext);
 
     CompilationSupport compilationSupport =
         new CrosstoolCompilationSupport(ruleContext)
+            .validateAttributes()
             .registerCompileAndArchiveActions(common)
             .registerFullyLinkAction(
                 common.getObjcProvider(),