Use Labels, rather than PathFragments, to represent Skylark loads internally. The load location for a Skylark Aspect is specified via a PathFragment, for consistency with current non-Aspect Skylark loads.

This should be a semantics-preserving change for users. In a subsequent CL, I'll change the Skylark syntax to allow load statements to use labels as well as paths, with the goal of eventually deprecating the latter.

Also:

- Removed the hack for handling relative loads in the prelude file.

- Refactored some redundant functionality in PackageFunction and SkylarkImportLookupFunction for handling loads.

- Removed the ability to put the BUILD file for the package containing a Skylark file under a different package root than the Skylark file itself. This functionality isn't currently used and is inconsistent with Blaze's handling of the package path elsewhere.

- Added BUILD files to a number of tests that load Skylark files; this is consistent with the requirement that all Skylark files need to be part of some package.

- Changed the constants used to set the location of the prelude file from paths to labels.

--
MOS_MIGRATED_REVID=107741568

1 files changed, 3 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/RuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/packages/RuleClassProvider.java
index db69c2494f..55aa950d2d 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RuleClassProvider.java
@@ -14,6 +14,7 @@
 
 package com.google.devtools.build.lib.packages;
 
+import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.packages.NativeAspectClass.NativeAspectFactory;
 import com.google.devtools.build.lib.syntax.Environment;
@@ -31,9 +32,9 @@ import javax.annotation.Nullable;
 public interface RuleClassProvider {
 
   /**
-   * Workspace relative path to the prelude file.
+   * Label referencing the prelude file.
    */
-  PathFragment getPreludePath();
+  Label getPreludeLabel();
 
   /**
    * The default runfiles prefix (may be overwritten by the WORKSPACE file).