Roll back using labels rather than PathFragments for skylark loads.

RELNOTES:

--
MOS_MIGRATED_REVID=103606693

1 files changed, 26 insertions, 68 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
index 29cc2e8f8a..65fa3f0a96 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ASTFileLookupValue.java
@@ -14,90 +14,48 @@
 
 package com.google.devtools.build.lib.skyframe;
 
-import com.google.common.base.Preconditions;
-import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.syntax.BuildFileAST;
 import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.SkyValue;
 
+import javax.annotation.Nullable;
+
 /**
- * A value that represents an AST file lookup result. There are two subclasses: one for the
- * case where the file is found, and another for the case where the file is missing (but there
- * are no other errors).
+ * A value that represents an AST file lookup result.
  */
-public abstract class ASTFileLookupValue implements SkyValue {
-  public abstract boolean lookupSuccessful();
-  public abstract BuildFileAST getAST();
-  public abstract String getErrorMsg();
-  
-  /*
-   * If the file is found, this class encapsulates the parsed AST.
-   */
-  private static class ASTLookupWithFile extends ASTFileLookupValue {
-    private final BuildFileAST ast;
-
-    private ASTLookupWithFile(BuildFileAST ast) {
-      Preconditions.checkNotNull(ast);
-      this.ast = ast;
-    }
+public class ASTFileLookupValue implements SkyValue {
 
-    @Override
-    public boolean lookupSuccessful() {
-      return true;
-    }
+  private static final ASTFileLookupValue NO_FILE = new ASTFileLookupValue(null);
 
-    @Override
-    public BuildFileAST getAST() {
-      return this.ast;
-    }
+  @Nullable private final BuildFileAST ast;
 
-    @Override
-    public String getErrorMsg() {
-      throw new IllegalStateException("can't retrieve error for successful lookup");
-    }
+  private ASTFileLookupValue(@Nullable BuildFileAST ast) {
+    this.ast = ast;
   }
- 
-  /*
-   * If the file isn't found, this class encapsulates a message with the reason.
-   */
-  private static class ASTLookupNoFile extends ASTFileLookupValue {
-    private final String errorMsg;
 
-    private ASTLookupNoFile(String errorMsg) {
-      this.errorMsg = Preconditions.checkNotNull(errorMsg);
-    }
-
-    @Override
-    public boolean lookupSuccessful() {
-      return false;
-    }
-
-    @Override
-    public BuildFileAST getAST() {
-      throw new IllegalStateException("can't retrieve AST for unsuccessful lookup");
-    }
-
-    @Override
-    public String getErrorMsg() {
-      return this.errorMsg;
-    }
+  public static ASTFileLookupValue noFile() {
+    return NO_FILE;
   }
 
-  static ASTFileLookupValue forBadPackage(Label fileLabel, String reason) {
-    return new ASTLookupNoFile(
-        String.format("Unable to load package for '%s': %s", fileLabel, reason));
+  public static ASTFileLookupValue withFile(BuildFileAST ast) {
+    return new ASTFileLookupValue(ast);
   }
-  
-  static ASTFileLookupValue forBadFile(Label fileLabel) {
-    return new ASTLookupNoFile(
-        String.format("Unable to load file '%s': file doesn't exist or isn't a file", fileLabel));
+
+  /**
+   * Returns the original AST file.
+   */
+  @Nullable public BuildFileAST getAST() {
+    return ast;
   }
-  
-  public static ASTFileLookupValue withFile(BuildFileAST ast) {
-    return new ASTLookupWithFile(ast);
+
+  static SkyKey key(PackageIdentifier astFileIdentifier) {
+    return new SkyKey(SkyFunctions.AST_FILE_LOOKUP, astFileIdentifier);
   }
 
-  static SkyKey key(Label astFileLabel) {
-    return new SkyKey(SkyFunctions.AST_FILE_LOOKUP, astFileLabel);
+  static final class ASTLookupInputException extends Exception {
+    ASTLookupInputException(String msg) {
+      super(msg);
+    }
   }
 }