Remap repository names inside load statements in BUILD files if the repository name is remapped.

For example if main/WORKSPACE contains:
local_repository(
    name = "a",
    path = "../a",
    repo_mapping = {"@x" : "@y"},
)

a/BUILD
load("@x//:sample.bzl", "sample")

Then the load in a/BUILD will be resolved as "@y//:sample.bzl"

RELNOTES: None
PiperOrigin-RevId: 200227431

7 files changed, 133 insertions, 36 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
index 2651e65d82..4e1d59e9e3 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/BuildView.java
@@ -539,7 +539,9 @@ public class BuildView {
         }
         SkylarkImport skylarkImport;
         try {
-          skylarkImport = SkylarkImports.create(bzlFileLoadLikeString);
+          skylarkImport =
+              SkylarkImports.create(
+                  bzlFileLoadLikeString, /* repositoryMapping= */ ImmutableMap.of());
         } catch (SkylarkImportSyntaxException e) {
           throw new ViewCreationFailedException(
               String.format("Invalid aspect '%s': %s", aspect, e.getMessage()), e);
diff --git a/src/main/java/com/google/devtools/build/lib/cmdline/Label.java b/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
index 61805ca5ae..9d14e6d7d8 100644
--- a/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
+++ b/src/main/java/com/google/devtools/build/lib/cmdline/Label.java
@@ -15,6 +15,7 @@ package com.google.devtools.build.lib.cmdline;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ComparisonChain;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Interner;
 import com.google.devtools.build.lib.actions.CommandLineItem;
@@ -115,8 +116,36 @@ public final class Label
    *
    * @param defaultToMain Treat labels in the default repository as being in the main one instead.
    */
+  @Deprecated
+  // TODO(dannark): Remove usages of this method, use other parseAbsolute() instead
   public static Label parseAbsolute(String absName, boolean defaultToMain)
       throws LabelSyntaxException {
+    return parseAbsolute(absName, defaultToMain, /* repositoryMapping= */ ImmutableMap.of());
+  }
+
+  /**
+   * Factory for Labels from absolute string form. e.g.
+   *
+   * <pre>
+   * //foo/bar
+   * //foo/bar:quux
+   * {@literal @}foo
+   * {@literal @}foo//bar
+   * {@literal @}foo//bar:baz
+   * </pre>
+   *
+   * <p>Labels that begin with a repository name may have the repository name remapped to a
+   * different name if it appears in {@code repositoryMapping}. This happens if the current
+   * repository being evaluated is external to the main repository and the main repository set the
+   * {@code repo_mapping} attribute when declaring this repository.
+   *
+   * @param defaultToMain Treat labels in the default repository as being in the main one instead.
+   */
+  public static Label parseAbsolute(
+      String absName,
+      boolean defaultToMain,
+      ImmutableMap<RepositoryName, RepositoryName> repositoryMapping)
+      throws LabelSyntaxException {
     String repo = defaultToMain ? "@" : RepositoryName.DEFAULT_REPOSITORY;
     int packageStartPos = absName.indexOf("//");
     if (packageStartPos > 0) {
@@ -134,12 +163,21 @@ public final class Label
       if (repo.isEmpty() && ABSOLUTE_PACKAGE_NAMES.contains(packageFragment)) {
         repo = "@";
       }
-      return create(PackageIdentifier.create(repo, packageFragment), labelParts.getTargetName());
+      RepositoryName globalRepoName = getGlobalRepoName(repo, repositoryMapping);
+      return create(
+          PackageIdentifier.create(globalRepoName, packageFragment), labelParts.getTargetName());
     } catch (BadLabelException e) {
       throw new LabelSyntaxException(e.getMessage());
     }
   }
 
+  private static RepositoryName getGlobalRepoName(
+      String repo, ImmutableMap<RepositoryName, RepositoryName> repositoryMapping)
+      throws LabelSyntaxException {
+    RepositoryName repoName = RepositoryName.create(repo);
+    return repositoryMapping.getOrDefault(repoName, repoName);
+  }
+
   /**
    * Alternate factory method for Labels from absolute strings. This is a convenience method for
    * cases when a Label needs to be initialized statically, so the declared exception is
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
index d9da36f945..108a0cf426 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
@@ -1246,12 +1246,17 @@ public final class PackageFactory {
     // Run the lexer and parser with a local reporter, so that errors from other threads do not
     // show up below.
     BuildFileAST buildFileAST =
-        parseBuildFile(packageId, input, preludeStatements, localReporterForParsing);
+        parseBuildFile(
+            packageId,
+            input,
+            preludeStatements,
+            /* repositoryMapping= */ ImmutableMap.of(),
+            localReporterForParsing);
     AstParseResult astParseResult =
         new AstParseResult(buildFileAST, localReporterForParsing);
     return createPackageFromAst(
         workspaceName,
-        /*repositoryMapping=*/ ImmutableMap.of(),
+        /* repositoryMapping= */ ImmutableMap.of(),
         packageId,
         buildFile,
         astParseResult,
@@ -1266,10 +1271,12 @@ public final class PackageFactory {
       PackageIdentifier packageId,
       ParserInputSource in,
       List<Statement> preludeStatements,
+      ImmutableMap<RepositoryName, RepositoryName> repositoryMapping,
       ExtendedEventHandler eventHandler) {
     // Logged messages are used as a testability hook tracing the parsing progress
     logger.fine("Starting to parse " + packageId);
-    BuildFileAST buildFileAST = BuildFileAST.parseBuildFile(in, preludeStatements, eventHandler);
+    BuildFileAST buildFileAST =
+        BuildFileAST.parseBuildFile(in, preludeStatements, repositoryMapping, eventHandler);
     logger.fine("Finished parsing of " + packageId);
     return buildFileAST;
   }
@@ -1373,10 +1380,10 @@ public final class PackageFactory {
                 packageId,
                 buildFile,
                 input,
-                /*preludeStatements=*/ ImmutableList.<Statement>of(),
-                /*imports=*/ ImmutableMap.<String, Extension>of(),
-                /*skylarkFileDependencies=*/ ImmutableList.<Label>of(),
-                /*defaultVisibility=*/ ConstantRuleVisibility.PUBLIC,
+                /* preludeStatements= */ ImmutableList.<Statement>of(),
+                /* imports= */ ImmutableMap.<String, Extension>of(),
+                /* skylarkFileDependencies= */ ImmutableList.<Label>of(),
+                /* defaultVisibility= */ ConstantRuleVisibility.PUBLIC,
                 semantics,
                 globber)
             .build();
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
index 05189fb12c..ce4116cc57 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PackageFunction.java
@@ -1220,7 +1220,7 @@ public class PackageFunction implements SkyFunction {
           StoredEventHandler astParsingEventHandler = new StoredEventHandler();
           BuildFileAST ast =
               PackageFactory.parseBuildFile(
-                  packageId, input, preludeStatements, astParsingEventHandler);
+                  packageId, input, preludeStatements, repositoryMapping, astParsingEventHandler);
           astParseResult = new AstParseResult(ast, astParsingEventHandler);
           astCache.put(packageId, astParseResult);
         }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceASTFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceASTFunction.java
index a8d14cae61..d2e7ce8741 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceASTFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceASTFunction.java
@@ -15,6 +15,7 @@
 package com.google.devtools.build.lib.skyframe;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.actions.FileValue;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.packages.BuildFileContainsErrorsException;
@@ -73,6 +74,7 @@ public class WorkspaceASTFunction implements SkyFunction {
             BuildFileAST.parseBuildFile(
                 ParserInputSource.create(bytes, repoWorkspace.asFragment()),
                 ast.getStatements(),
+                /* repositoryMapping= */ ImmutableMap.of(),
                 env.getListener());
         if (ast.containsErrors()) {
           throw new WorkspaceASTFunctionException(
@@ -81,11 +83,14 @@ public class WorkspaceASTFunction implements SkyFunction {
               Transience.PERSISTENT);
         }
       }
-      ast = BuildFileAST.parseBuildFile(
-          ParserInputSource.create(ruleClassProvider.getDefaultWorkspaceSuffix(),
-              PathFragment.create("/DEFAULT.WORKSPACE.SUFFIX")),
-          ast.getStatements(),
-          env.getListener());
+      ast =
+          BuildFileAST.parseBuildFile(
+              ParserInputSource.create(
+                  ruleClassProvider.getDefaultWorkspaceSuffix(),
+                  PathFragment.create("/DEFAULT.WORKSPACE.SUFFIX")),
+              ast.getStatements(),
+              /* repositoryMapping= */ ImmutableMap.of(),
+              env.getListener());
       if (ast.containsErrors()) {
         throw new WorkspaceASTFunctionException(
             new BuildFileContainsErrorsException(
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java b/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
index ca6307fa8a..801013b207 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BuildFileAST.java
@@ -16,7 +16,9 @@ package com.google.devtools.build.lib.syntax;
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.hash.HashCode;
+import com.google.devtools.build.lib.cmdline.RepositoryName;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.events.Location;
@@ -68,6 +70,7 @@ public class BuildFileAST extends ASTNode {
       List<Statement> preludeStatements,
       ParseResult result,
       String contentHashCode,
+      ImmutableMap<RepositoryName, RepositoryName> repositoryMapping,
       EventHandler eventHandler) {
     ImmutableList<Statement> statements =
         ImmutableList.<Statement>builder()
@@ -77,7 +80,7 @@ public class BuildFileAST extends ASTNode {
 
     boolean containsErrors = result.containsErrors;
     Pair<Boolean, ImmutableList<SkylarkImport>> skylarkImports =
-        fetchLoads(statements, eventHandler);
+        fetchLoads(statements, repositoryMapping, eventHandler);
     containsErrors |= skylarkImports.first;
     return new BuildFileAST(
         statements,
@@ -99,7 +102,7 @@ public class BuildFileAST extends ASTNode {
       if (stmt instanceof LoadStatement) {
         String str = ((LoadStatement) stmt).getImport().getValue();
         try {
-          imports.add(SkylarkImports.create(str));
+          imports.add(SkylarkImports.create(str, /* repositoryMapping= */ ImmutableMap.of()));
         } catch (SkylarkImportSyntaxException e) {
           throw new IllegalStateException(
               "Cannot create SkylarImport for '" + str + "'. This is an internal error.");
@@ -120,14 +123,16 @@ public class BuildFileAST extends ASTNode {
    * imports that could be resolved.
    */
   private static Pair<Boolean, ImmutableList<SkylarkImport>> fetchLoads(
-      List<Statement> statements, EventHandler eventHandler) {
+      List<Statement> statements,
+      ImmutableMap<RepositoryName, RepositoryName> repositoryMapping,
+      EventHandler eventHandler) {
     ImmutableList.Builder<SkylarkImport> imports = ImmutableList.builder();
     boolean error = false;
     for (Statement stmt : statements) {
       if (stmt instanceof LoadStatement) {
         String importString = ((LoadStatement) stmt).getImport().getValue();
         try {
-          imports.add(SkylarkImports.create(importString));
+          imports.add(SkylarkImports.create(importString, repositoryMapping));
         } catch (SkylarkImportSyntaxException e) {
           eventHandler.handle(Event.error(stmt.getLocation(), e.getMessage()));
           error = true;
@@ -272,20 +277,28 @@ public class BuildFileAST extends ASTNode {
   }
 
   /**
-   * Parse the specified build file, returning its AST. All errors during
-   * scanning or parsing will be reported to the reporter.
+   * Parse the specified build file, returning its AST. All errors during scanning or parsing will
+   * be reported to the reporter.
    */
-  public static BuildFileAST parseBuildFile(ParserInputSource input,
-                                            List<Statement> preludeStatements,
-                                            EventHandler eventHandler) {
+  public static BuildFileAST parseBuildFile(
+      ParserInputSource input,
+      List<Statement> preludeStatements,
+      ImmutableMap<RepositoryName, RepositoryName> repositoryMapping,
+      EventHandler eventHandler) {
     Parser.ParseResult result = Parser.parseFile(input, eventHandler);
-    return create(preludeStatements, result, /*contentHashCode=*/ null, eventHandler)
+    return create(
+            preludeStatements, result, /* contentHashCode= */ null, repositoryMapping, eventHandler)
         .validateBuildFile(eventHandler);
   }
 
   public static BuildFileAST parseBuildFile(ParserInputSource input, EventHandler eventHandler) {
     Parser.ParseResult result = Parser.parseFile(input, eventHandler);
-    return create(ImmutableList.<Statement>of(), result, /*contentHashCode=*/ null, eventHandler)
+    return create(
+            /* preludeStatements= */ ImmutableList.<Statement>of(),
+            result,
+            /* contentHashCode= */ null,
+            /* repositoryMapping= */ ImmutableMap.of(),
+            eventHandler)
         .validateBuildFile(eventHandler);
   }
 
@@ -295,13 +308,21 @@ public class BuildFileAST extends ASTNode {
     ParserInputSource input = ParserInputSource.create(bytes, path);
     Parser.ParseResult result = Parser.parseFile(input, eventHandler);
     return create(
-        ImmutableList.of(), result,
-        HashCode.fromBytes(digest).toString(), eventHandler);
+        /* preludeStatements= */ ImmutableList.of(),
+        result,
+        HashCode.fromBytes(digest).toString(),
+        /* repositoryMapping= */ ImmutableMap.of(),
+        eventHandler);
   }
 
   public static BuildFileAST parseSkylarkFile(ParserInputSource input, EventHandler eventHandler) {
     Parser.ParseResult result = Parser.parseFile(input, eventHandler);
-    return create(ImmutableList.<Statement>of(), result, /*contentHashCode=*/ null, eventHandler);
+    return create(
+        /* preludeStatements= */ ImmutableList.<Statement>of(),
+        result,
+        /* contentHashCode= */ null,
+        /* repositoryMapping= */ ImmutableMap.of(),
+        eventHandler);
   }
 
   /**
@@ -320,10 +341,10 @@ public class BuildFileAST extends ASTNode {
             .addAll(result.statements)
             .build(),
         result.containsErrors,
-        /*contentHashCode=*/null,
+        /* contentHashCode= */null,
         result.location,
         ImmutableList.copyOf(result.comments),
-        /*imports=*/null);
+        /* imports= */null);
   }
 
   /**
@@ -356,7 +377,12 @@ public class BuildFileAST extends ASTNode {
     String str = Joiner.on("\n").join(content);
     ParserInputSource input = ParserInputSource.create(str, PathFragment.EMPTY_FRAGMENT);
     Parser.ParseResult result = Parser.parseFile(input, eventHandler);
-    return create(ImmutableList.of(), result, null, eventHandler);
+    return create(
+        /* preludeStatements= */ ImmutableList.of(),
+        result,
+        /* contentHashCode= */ null,
+        /* repositoryMapping= */ ImmutableMap.of(),
+        eventHandler);
   }
 
   public static BuildFileAST parseBuildString(EventHandler eventHandler, String... content) {
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkImports.java b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkImports.java
index 71f1bffc8d..6cedeed40a 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/SkylarkImports.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/SkylarkImports.java
@@ -14,10 +14,12 @@
 package com.google.devtools.build.lib.syntax;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.cmdline.Label;
 import com.google.devtools.build.lib.cmdline.LabelSyntaxException;
 import com.google.devtools.build.lib.cmdline.LabelValidator;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
+import com.google.devtools.build.lib.cmdline.RepositoryName;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -235,18 +237,35 @@ public class SkylarkImports {
 
   /**
    * Creates and syntactically validates a {@link SkylarkImports} instance from a string.
-   * <p>
-   * There four syntactic import variants: Absolute paths, relative paths, absolute labels, and
-   * relative labels
+   *
+   * <p>There are four syntactic import variants: Absolute paths, relative paths, absolute labels,
+   * and relative labels
    *
    * @throws SkylarkImportSyntaxException if the string is not a valid Skylark import.
    */
   public static SkylarkImport create(String importString) throws SkylarkImportSyntaxException {
+    return create(importString, /* repositoryMapping= */ ImmutableMap.of());
+  }
+
+  /**
+   * Creates and syntactically validates a {@link SkylarkImports} instance from a string.
+   *
+   * <p>There four syntactic import variants: Absolute paths, relative paths, absolute labels, and
+   * relative labels
+   *
+   * <p>Absolute labels will have the repository portion of the label remapped if it is present in
+   * {@code repositoryMapping}
+   *
+   * @throws SkylarkImportSyntaxException if the string is not a valid Skylark import.
+   */
+  public static SkylarkImport create(
+      String importString, ImmutableMap<RepositoryName, RepositoryName> repositoryMapping)
+      throws SkylarkImportSyntaxException {
     if (importString.startsWith("//") || importString.startsWith("@")) {
       // Absolute label.
       Label importLabel;
       try {
-        importLabel = Label.parseAbsolute(importString, false);
+        importLabel = Label.parseAbsolute(importString, false, repositoryMapping);
       } catch (LabelSyntaxException e) {
         throw new SkylarkImportSyntaxException(INVALID_LABEL_PREFIX + e.getMessage());
       }