Add ActionKeyContext to Action#getKey.

This key context can be used by actions to share partial key computations, for instance when computing MD5s for nested sets.

RELNOTES: None
PiperOrigin-RevId: 177359607

1 files changed, 13 insertions, 9 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/actions/MutableActionGraph.java b/src/main/java/com/google/devtools/build/lib/actions/MutableActionGraph.java
index 1b1955a5e5..24a74ad28c 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/MutableActionGraph.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/MutableActionGraph.java
@@ -61,15 +61,19 @@ public interface MutableActionGraph extends ActionGraph {
    * about the artifact for which the conflict is found, and data about the two conflicting actions
    * and their owners.
    */
-  public static final class ActionConflictException extends Exception {
+  final class ActionConflictException extends Exception {
 
+    private final ActionKeyContext actionKeyContext;
     private final Artifact artifact;
     private final ActionAnalysisMetadata previousAction;
     private final ActionAnalysisMetadata attemptedAction;
     
     private static final int MAX_DIFF_ARTIFACTS_TO_REPORT = 5;
 
-    public ActionConflictException(Artifact artifact, ActionAnalysisMetadata previousAction,
+    public ActionConflictException(
+        ActionKeyContext actionKeyContext,
+        Artifact artifact,
+        ActionAnalysisMetadata previousAction,
         ActionAnalysisMetadata attemptedAction) {
       super(
           String.format(
@@ -77,6 +81,7 @@ public interface MutableActionGraph extends ActionGraph {
               artifact.prettyPrint(),
               previousAction.prettyPrint(),
               attemptedAction.prettyPrint()));
+      this.actionKeyContext = actionKeyContext;
       this.artifact = artifact;
       this.previousAction = previousAction;
       this.attemptedAction = attemptedAction;
@@ -91,7 +96,7 @@ public interface MutableActionGraph extends ActionGraph {
           "file '"
               + artifact.prettyPrint()
               + "' is generated by these conflicting actions:\n"
-              + suffix(attemptedAction, previousAction);
+              + suffix(actionKeyContext, attemptedAction, previousAction);
       eventListener.handle(Event.error(msg));
     }
 
@@ -143,14 +148,13 @@ public interface MutableActionGraph extends ActionGraph {
       }
     }
 
-    private static String getKey(ActionAnalysisMetadata action) {
-      return action instanceof Action
-          ? ((Action) action).getKey()
-          : null;
+    private static String getKey(ActionKeyContext actionKeyContext, ActionAnalysisMetadata action) {
+      return action instanceof Action ? ((Action) action).getKey(actionKeyContext) : null;
     }
 
     // See also Actions.canBeShared()
-    private static String suffix(ActionAnalysisMetadata a, ActionAnalysisMetadata b) {
+    private static String suffix(
+        ActionKeyContext actionKeyContext, ActionAnalysisMetadata a, ActionAnalysisMetadata b) {
       // Note: the error message reveals to users the names of intermediate files that are not
       // documented in the BUILD language.  This error-reporting logic is rather elaborate but it
       // does help to diagnose some tricky situations.
@@ -167,7 +171,7 @@ public interface MutableActionGraph extends ActionGraph {
       addStringDetail(sb, "Configuration", aNull ? null : aOwner.getConfigurationChecksum(),
           bNull ? null : bOwner.getConfigurationChecksum());
       addStringDetail(sb, "Mnemonic", a.getMnemonic(), b.getMnemonic());
-      addStringDetail(sb, "Action key", getKey(a), getKey(b));
+      addStringDetail(sb, "Action key", getKey(actionKeyContext, a), getKey(actionKeyContext, b));
 
       if ((a instanceof ActionExecutionMetadata) && (b instanceof ActionExecutionMetadata)) {
         addStringDetail(