Record repo mapping entries for labels in module extension tags

The mapping of an apparent name in a module extension tag's `attr.label`
attribute to the corresponding canonical name has to be recorded in the
lockfile so that instantiated repo rules don't reference the stale
repos.

Fixes bazelbuild#25063

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/BazelLockFileValue.java

@@ -38,7 +38,7 @@ public abstract class BazelLockFileValue implements SkyValue {
   // https://cs.opensource.google/bazel/bazel/+/release-7.3.0:src/main/java/com/google/devtools/build/lib/bazel/bzlmod/BazelLockFileModule.java;l=120-127;drc=5f5355b75c7c93fba1e15f6658f308953f4baf51
   // While this hack exists on 7.x, lockfile version increments should be done 2 at a time (i.e.
   // keep this number even).
-  public static final int LOCK_FILE_VERSION = 16;
+  public static final int LOCK_FILE_VERSION = 18;
 
   @SerializationConstant public static final SkyKey KEY = () -> SkyFunctions.BAZEL_LOCK_FILE;
 

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/RegularRunnableExtension.java

@@ -267,7 +267,7 @@ private RunModuleExtensionResult runInternal(
     try (Mutability mu =
             Mutability.create("module extension", usagesValue.getExtensionUniqueName());
         ModuleExtensionContext moduleContext =
-            createContext(env, usagesValue, starlarkSemantics, extensionId)) {
+            createContext(env, usagesValue, starlarkSemantics, extensionId, repoMappingRecorder)) {
       StarlarkThread thread =
           StarlarkThread.create(
               mu,
@@ -325,7 +325,8 @@ private ModuleExtensionContext createContext(
       Environment env,
       SingleExtensionUsagesValue usagesValue,
       StarlarkSemantics starlarkSemantics,
-      ModuleExtensionId extensionId)
+      ModuleExtensionId extensionId,
+      Label.RepoMappingRecorder repoMappingRecorder)
       throws ExternalDepsException {
     Path workingDirectory =
         directories
@@ -340,7 +341,8 @@ private ModuleExtensionContext createContext(
               abridgedModule,
               extension,
               usagesValue.getRepoMappings().get(moduleKey),
-              usagesValue.getExtensionUsages().get(moduleKey)));
+              usagesValue.getExtensionUsages().get(moduleKey),
+              repoMappingRecorder));
     }
     ModuleExtensionUsage rootUsage = usagesValue.getExtensionUsages().get(ModuleKey.ROOT);
     boolean rootModuleHasNonDevDependency =

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/StarlarkBazelModule.java

@@ -19,6 +19,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import com.google.devtools.build.docgen.annot.DocCategory;
+import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.cmdline.RepositoryMapping;
 import com.google.devtools.build.lib.packages.LabelConverter;
@@ -107,12 +108,14 @@ public static StarlarkBazelModule create(
       AbridgedModule module,
       ModuleExtension extension,
       RepositoryMapping repoMapping,
-      @Nullable ModuleExtensionUsage usage)
+      @Nullable ModuleExtensionUsage usage,
+      Label.RepoMappingRecorder repoMappingRecorder)
       throws ExternalDepsException {
     LabelConverter labelConverter =
         new LabelConverter(
             PackageIdentifier.create(repoMapping.ownerRepo(), PathFragment.EMPTY_FRAGMENT),
-            repoMapping);
+            repoMapping,
+            repoMappingRecorder);
     ImmutableList<Tag> tags = usage == null ? ImmutableList.of() : usage.getTags();
     HashMap<String, ArrayList<TypeCheckedTag>> typeCheckedTags = new HashMap<>();
     for (String tagClassName : extension.tagClasses().keySet()) {

src/main/java/com/google/devtools/build/lib/packages/LabelConverter.java

@@ -21,6 +21,7 @@
 import com.google.devtools.build.lib.cmdline.RepositoryMapping;
 import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;
 import net.starlark.java.eval.StarlarkThread;
 
 /**
@@ -44,16 +45,35 @@ public static LabelConverter forBzlEvaluatingThread(StarlarkThread thread) {
 
   private final Label.PackageContext packageContext;
   private final Map<String, Label> labelCache = new HashMap<>();
+  @Nullable private final Label.RepoMappingRecorder repoMappingRecorder;
 
-  public LabelConverter(Label.PackageContext packageContext) {
+  private LabelConverter(
+      Label.PackageContext packageContext,
+      @Nullable Label.RepoMappingRecorder repoMappingRecorder) {
     this.packageContext = packageContext;
+    this.repoMappingRecorder = repoMappingRecorder;
+  }
+
+  public LabelConverter(Label.PackageContext packageContext) {
+    this(packageContext, null);
   }
 
   /** Creates a label converter using the given base package and repo mapping. */
   public LabelConverter(PackageIdentifier base, RepositoryMapping repositoryMapping) {
     this(Label.PackageContext.of(base, repositoryMapping));
   }
 
+  /**
+   * Creates a label converter using the given base package and repo mapping, recording all repo
+   * mapping lookups in the given recorder.
+   */
+  public LabelConverter(
+      PackageIdentifier base,
+      RepositoryMapping repositoryMapping,
+      Label.RepoMappingRecorder repoMappingRecorder) {
+    this(Label.PackageContext.of(base, repositoryMapping), repoMappingRecorder);
+  }
+
   /** Returns the base package identifier that relative labels will be resolved against. */
   PackageIdentifier getBasePackage() {
     return packageContext.packageIdentifier();
@@ -67,7 +87,7 @@ public Label convert(String input) throws LabelSyntaxException {
     // label-strings across all their attribute values.
     Label converted = labelCache.get(input);
     if (converted == null) {
-      converted = Label.parseWithPackageContext(input, packageContext);
+      converted = Label.parseWithPackageContext(input, packageContext, repoMappingRecorder);
       labelCache.put(input, converted);
     }
     return converted;

src/test/java/com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionResolutionTest.java

@@ -873,6 +873,24 @@ public void labels_passedOnToRepoRule() throws Exception {
     }
     assertThat(result.get(skyKey).getModule().getGlobal("data"))
         .isEqualTo("get up at 6am. go to bed at 11pm.");
+
+    SkyKey extensionSkyKey =
+        SingleExtensionValue.key(
+            ModuleExtensionId.create(
+                Label.parseCanonicalUnchecked("@@ext+//:defs.bzl"), "ext", Optional.empty()));
+    EvaluationResult<SingleExtensionValue> extensionResult =
+        evaluator.evaluate(ImmutableList.of(extensionSkyKey), evaluationContext);
+    if (extensionResult.hasError()) {
+      throw extensionResult.getError().getException();
+    }
+    assertThat(
+            extensionResult
+                .get(extensionSkyKey)
+                .lockFileInfo()
+                .get()
+                .moduleExtension()
+                .getRecordedRepoMappingEntries())
+        .containsCell(RepositoryName.create("foo+"), "bar", RepositoryName.create("bar+"));
   }
 
   @Test

src/test/java/com/google/devtools/build/lib/bazel/bzlmod/StarlarkBazelModuleTest.java

@@ -90,6 +90,7 @@ public void basic() throws Exception {
     Module module = buildModule("foo", "1.0").setKey(fooKey).addDep("bar", barKey).build();
     AbridgedModule abridgedModule = AbridgedModule.from(module);
 
+    Label.RepoMappingRecorder repoMappingRecorder = new Label.RepoMappingRecorder();
     StarlarkBazelModule moduleProxy =
         StarlarkBazelModule.create(
             abridgedModule,
@@ -98,7 +99,8 @@ public void basic() throws Exception {
                 ImmutableMap.of(
                     fooKey, fooKey.getCanonicalRepoNameWithoutVersion(),
                     barKey, barKey.getCanonicalRepoNameWithoutVersion())),
-            usage);
+            usage,
+            repoMappingRecorder);
 
     assertThat(moduleProxy.getName()).isEqualTo("foo");
     assertThat(moduleProxy.getVersion()).isEqualTo("1.0");
@@ -125,6 +127,9 @@ public void basic() throws Exception {
             StarlarkList.immutableOf(
                 Label.parseCanonical("@@foo+//:pom.xml"),
                 Label.parseCanonical("@@bar+//:pom.xml")));
+
+    assertThat(repoMappingRecorder.recordedEntries())
+        .containsCell(RepositoryName.create("foo+"), "bar", RepositoryName.create("bar+"));
   }
 
   @Test
@@ -145,7 +150,8 @@ public void unknownTagClass() throws Exception {
                     extension,
                     module.getRepoMappingWithBazelDepsOnly(
                         ImmutableMap.of(fooKey, fooKey.getCanonicalRepoNameWithoutVersion())),
-                    usage));
+                    usage,
+                    new Label.RepoMappingRecorder()));
     assertThat(e).hasMessageThat().contains("does not have a tag class named blep");
   }
 }