Support running tests on the target platform

This change *includes* another change by @juliexxia that was previously
merged and rolled back:
bazelbuild@c266ac9

This adds an --use_target_platform_for_tests option that changes tests
to use the execution properties from the target platform rather than
the host platform. I believe that the code is currently incorrect -
if the host and target platforms differ, then tests are cross-compiled
for the target platform, but use the execution properties for the host
platform.

This matters for remote execution, where host and target platform may
be different CPU architectures and operating systems (e.g., compiling
on x64 Linux and running on ARM64 Mac). Currently, such tests will
typically fail to run if they contain architecture or OS-specific code.

Progress on bazelbuild#10799.

Change-Id: I774bd4442044d6725e78f496b9991368e73ffa00

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

@@ -148,13 +148,16 @@ public static LabelLateBoundDefault<BuildConfiguration> getCoverageOutputGenerat
             return runUnder != null ? runUnder.getLabel() : null;
           });
 
+  public static final String TEST_RUNNER_EXEC_GROUP = "test";
+
   /**
    * A base rule for all test rules.
    */
   public static final class TestBaseRule implements RuleDefinition {
     @Override
     public RuleClass build(RuleClass.Builder builder, RuleDefinitionEnvironment env) {
       return builder
+          .addExecGroup(TEST_RUNNER_EXEC_GROUP)
           .requiresConfigurationFragments(TestConfiguration.class)
           // TestConfiguration only needed to create TestAction and TestProvider
           // Only necessary at top-level and can be skipped if trimmed.

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

@@ -14,6 +14,8 @@
 
 package com.google.devtools.build.lib.analysis;
 
+
+import static com.google.devtools.build.lib.analysis.BaseRuleClasses.TEST_RUNNER_EXEC_GROUP;
 import static com.google.devtools.build.lib.analysis.ToolchainCollection.DEFAULT_EXEC_GROUP_NAME;
 
 import com.google.common.annotations.VisibleForTesting;
@@ -468,6 +470,22 @@ public ActionOwner getActionOwner() {
     return getActionOwner(DEFAULT_EXEC_GROUP_NAME);
   }
 
+  /**
+   * Returns a special action owner for test actions. Test actions should run on the target platform
+   * rather than the host platform. Note that the value is not cached (on the assumption that this
+   * method is only called once).
+   */
+  public ActionOwner getTestActionOwner() {
+    ActionOwner actionOwner =
+        createActionOwner(
+            rule,
+            aspectDescriptors,
+            getConfiguration(),
+            getExecProperties(TEST_RUNNER_EXEC_GROUP, execProperties),
+            toolchainContexts == null ? null : toolchainContexts.getTargetPlatform());
+    return actionOwner;
+  }
+
   @Override
   @Nullable
   public ActionOwner getActionOwner(String execGroup) {

src/main/java/com/google/devtools/build/lib/analysis/test/TestActionBuilder.java

@@ -14,12 +14,14 @@
 
 package com.google.devtools.build.lib.analysis.test;
 
+import static com.google.devtools.build.lib.analysis.BaseRuleClasses.TEST_RUNNER_EXEC_GROUP;
 import static com.google.devtools.build.lib.packages.BuildType.LABEL;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.devtools.build.lib.actions.ActionInput;
+import com.google.devtools.build.lib.actions.ActionOwner;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.ArtifactRoot;
 import com.google.devtools.build.lib.actions.RunfilesSupplier;
@@ -329,6 +331,12 @@ private TestParams createTestAction(int shards) throws InterruptedException {
     ImmutableList.Builder<Artifact> coverageArtifacts = ImmutableList.builder();
     ImmutableList.Builder<ActionInput> testOutputs = ImmutableList.builder();
 
+    ActionOwner actionOwner = testConfiguration.useTargetPlatformForTests()
+        ? ruleContext.getTestActionOwner()
+        : ruleContext.getActionOwner(TEST_RUNNER_EXEC_GROUP);
+    if (actionOwner == null) {
+      actionOwner = ruleContext.getActionOwner();
+    }
     // Use 1-based indices for user friendliness.
     for (int shard = 0; shard < shardRuns; shard++) {
       String shardDir = shardRuns > 1 ? String.format("shard_%d_of_%d", shard + 1, shards) : null;
@@ -390,7 +398,7 @@ private TestParams createTestAction(int shards) throws InterruptedException {
         boolean splitCoveragePostProcessing = testConfiguration.splitCoveragePostProcessing();
         TestRunnerAction testRunnerAction =
             new TestRunnerAction(
-                ruleContext.getActionOwner(),
+                actionOwner,
                 inputs,
                 testRunfilesSupplier,
                 testActionExecutable,

src/main/java/com/google/devtools/build/lib/analysis/test/TestConfiguration.java

@@ -281,6 +281,14 @@ public static class TestOptions extends FragmentOptions {
         help = "If true, then Bazel will run coverage postprocessing for test in a new spawn.")
     public boolean splitCoveragePostProcessing;
 
+    @Option(
+        name = "use_target_platform_for_tests",
+        defaultValue = "false",
+        documentationCategory = OptionDocumentationCategory.EXECUTION_STRATEGY,
+        effectTags = {OptionEffectTag.EXECUTION},
+        help = "If true, then Bazel will run coverage postprocessing for test in a new spawn.")
+    public boolean useTargetPlatformForTests;
+
     @Override
     public FragmentOptions getHost() {
       TestOptions hostOptions = (TestOptions) getDefault();
@@ -391,6 +399,10 @@ public boolean splitCoveragePostProcessing() {
     return options.splitCoveragePostProcessing;
   }
 
+  public boolean useTargetPlatformForTests() {
+    return options.useTargetPlatformForTests;
+  }
+
   /**
    * Option converter that han handle two styles of value for "--runs_per_test":
    *