commit 3f0917a2cf0cb676598a5b21ab4c8d58b7e8d7a9
author brandjon <brandjon@google.com> Mon Oct 26 18:01:50 2020 -0700
committer Copybara-Service <copybara-worker@google.com> Mon Oct 26 18:03:01 2020 -0700
tree 02fe139f80e2faf145fc15642a1deb4234157436
parent d5d8677506e74dbe009c1fa8c1c5a4be5a98cffb

More validation on @_builtins loads

- Can only load from other builtins bzls
- No subpackages in builtins bzls

Also add more test cases, move test cases around.

StarlarkBuiltinsFunctionTest:
- Add assertion helper, factor removal of failFastHandler
- Add test of digest of StarlarkBuiltinsValue
- Move tests involving loads of builtins helpers to BuiltinsInjectionTest

BuiltinsInjectionTest:
- Replace build-without-asserting helper with build-and-assert-failure helper, factor removal of failFastHandler
- Test loading builtins helpers via relative label syntax
- Move tests of what symbols are accessible to StarlarkBuiltinsFunctionTest

Work toward #11437.

PiperOrigin-RevId: 339157512

src/main/java/com/google/devtools/build/lib/skyframe/BzlLoadFunction.java

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/BzlLoadFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/BzlLoadFunction.java
index b4d3065..f35d3f3 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/BzlLoadFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/BzlLoadFunction.java
@@ -531,13 +531,17 @@
   private BzlCompileValue.Key validatePackageAndGetCompileKey(
       BzlLoadValue.Key key, Environment env, StarlarkSemantics starlarkSemantics)
       throws BzlLoadFailedException, InterruptedException {
+    Label label = key.getLabel();
+
     // Bypass package lookup entirely if builtins.
     if (key.isBuiltins()) {
+      if (!label.getPackageName().isEmpty()) {
+        throw BzlLoadFailedException.noBuildFile(label, "@_builtins cannot have subpackages");
+      }
       return key.getCompileKey(getBuiltinsRoot(starlarkSemantics));
     }
 
     // Do package lookup.
-    Label label = key.getLabel();
     PathFragment dir = Label.getContainingDirectory(label);
     PackageIdentifier dirId = PackageIdentifier.create(label.getRepository(), dir);
     ContainingPackageLookupValue packageLookup;
@@ -777,6 +781,11 @@
             throw new LabelSyntaxException(
                 "Starlark files may not be loaded from the //external package");
           }
+          if (StarlarkBuiltinsValue.isBuiltinsRepo(base.getRepository())
+              && !StarlarkBuiltinsValue.isBuiltinsRepo(label.getRepository())) {
+            throw new LabelSyntaxException(
+                ".bzl files in @_builtins cannot load from outside of @_builtins");
+          }
           loads.add(Pair.of(module, label));
         } catch (LabelSyntaxException ex) {
           handler.handle(