Stage repository mapping manifest as a root symlink

By adding the repository mapping manifest to runfiles as a root symlink, it is staged as `foo.runfiles/_repo_mapping` with all execution strategies. This includes sandboxed and remote execution, which previously did not stage the manifest at all.

As a side effect, runfiles libraries can now find the repository mapping manifest via `rlocation("_repo_mapping")`.

Fixes #16643
Work towards #16124

Closes #16652.

PiperOrigin-RevId: 487532254
Change-Id: I9774b8930337c5967fce92a861cc0db71dea2f0f

src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java

@@ -386,11 +386,14 @@ static Map<PathFragment, Artifact> filterListForObscuringSymlinks(
    *     normal source tree entries, or runfile conflicts. May be null, in which case obscuring
    *     symlinks are silently discarded, and conflicts are overwritten.
    * @param location Location for eventHandler warnings. Ignored if eventHandler is null.
+   * @param repoMappingManifest repository mapping manifest to add as a root symlink. This manifest
+   *     has to be added automatically for every executable and is thus not part of the Runfiles
+   *     advertised by a configured target.
    * @return Map<PathFragment, Artifact> path fragment to artifact, of normal source tree entries
    *     and elements that live outside the source tree. Null values represent empty input files.
    */
   public Map<PathFragment, Artifact> getRunfilesInputs(
-      EventHandler eventHandler, Location location) {
+      EventHandler eventHandler, Location location, @Nullable Artifact repoMappingManifest) {
     ConflictChecker checker = new ConflictChecker(conflictPolicy, eventHandler, location);
     Map<PathFragment, Artifact> manifest = getSymlinksAsMap(checker);
     // Add artifacts (committed to inclusion on construction of runfiles).
@@ -417,6 +420,9 @@ public Map<PathFragment, Artifact> getRunfilesInputs(
       checker = new ConflictChecker(ConflictPolicy.WARN, eventHandler, location);
     }
     builder.add(getRootSymlinksAsMap(checker), checker);
+    if (repoMappingManifest != null) {
+      checker.put(builder.manifest, PathFragment.create("_repo_mapping"), repoMappingManifest);
+    }
     return builder.build();
   }
 

src/main/java/com/google/devtools/build/lib/analysis/RunfilesSupport.java

@@ -132,18 +132,20 @@ private static RunfilesSupport create(
     }
     Preconditions.checkState(!runfiles.isEmpty());
 
+    Artifact repoMappingManifest =
+        createRepoMappingManifestAction(ruleContext, runfiles, owningExecutable);
+
     Artifact runfilesInputManifest;
     Artifact runfilesManifest;
     if (createManifest) {
       runfilesInputManifest = createRunfilesInputManifestArtifact(ruleContext, owningExecutable);
       runfilesManifest =
-          createRunfilesAction(ruleContext, runfiles, buildRunfileLinks, runfilesInputManifest);
+          createRunfilesAction(
+              ruleContext, runfiles, buildRunfileLinks, runfilesInputManifest, repoMappingManifest);
     } else {
       runfilesInputManifest = null;
       runfilesManifest = null;
     }
-    Artifact repoMappingManifest =
-        createRepoMappingManifestAction(ruleContext, runfiles, owningExecutable);
     Artifact runfilesMiddleman =
         createRunfilesMiddleman(
             ruleContext, owningExecutable, runfiles, runfilesManifest, repoMappingManifest);
@@ -387,7 +389,8 @@ private static Artifact createRunfilesAction(
       ActionConstructionContext context,
       Runfiles runfiles,
       boolean createSymlinks,
-      Artifact inputManifest) {
+      Artifact inputManifest,
+      @Nullable Artifact repoMappingManifest) {
     // Compute the names of the runfiles directory and its MANIFEST file.
     context
         .getAnalysisEnvironment()
@@ -397,6 +400,7 @@ private static Artifact createRunfilesAction(
                 context.getActionOwner(),
                 inputManifest,
                 runfiles,
+                repoMappingManifest,
                 context.getConfiguration().remotableSourceManifestActions()));
 
     if (!createSymlinks) {
@@ -423,6 +427,7 @@ private static Artifact createRunfilesAction(
                 inputManifest,
                 runfiles,
                 outputManifest,
+                repoMappingManifest,
                 /*filesetRoot=*/ null));
     return outputManifest;
   }

src/main/java/com/google/devtools/build/lib/analysis/SingleRunfilesSupplier.java

@@ -34,10 +34,12 @@
 /** {@link RunfilesSupplier} implementation wrapping a single {@link Runfiles} directory mapping. */
 @AutoCodec
 public final class SingleRunfilesSupplier implements RunfilesSupplier {
+
   private final PathFragment runfilesDir;
   private final Runfiles runfiles;
   private final Supplier<Map<PathFragment, Artifact>> runfilesInputs;
   @Nullable private final Artifact manifest;
+  @Nullable private final Artifact repoMappingManifest;
   private final boolean buildRunfileLinks;
   private final boolean runfileLinksEnabled;
 
@@ -50,28 +52,31 @@ public static SingleRunfilesSupplier create(RunfilesSupport runfilesSupport) {
         runfilesSupport.getRunfiles(),
         /*runfilesCachingEnabled=*/ false,
         /*manifest=*/ null,
+        runfilesSupport.getRepoMappingManifest(),
         runfilesSupport.isBuildRunfileLinks(),
         runfilesSupport.isRunfilesEnabled());
   }
 
   /**
    * Same as {@link SingleRunfilesSupplier#SingleRunfilesSupplier(PathFragment, Runfiles, Artifact,
-   * boolean, boolean)}, except adds caching for {@linkplain Runfiles#getRunfilesInputs runfiles
-   * inputs}.
+   * Artifact, boolean, boolean)}, except adds caching for {@linkplain Runfiles#getRunfilesInputs
+   * runfiles inputs}.
    *
    * <p>The runfiles inputs are computed lazily and softly cached. Caching is shared across
    * instances created via {@link #withOverriddenRunfilesDir}.
    */
   public static SingleRunfilesSupplier createCaching(
       PathFragment runfilesDir,
       Runfiles runfiles,
+      @Nullable Artifact repoMappingManifest,
       boolean buildRunfileLinks,
       boolean runfileLinksEnabled) {
     return new SingleRunfilesSupplier(
         runfilesDir,
         runfiles,
         /*runfilesCachingEnabled=*/ true,
         /*manifest=*/ null,
+        repoMappingManifest,
         buildRunfileLinks,
         runfileLinksEnabled);
   }
@@ -92,13 +97,15 @@ public SingleRunfilesSupplier(
       PathFragment runfilesDir,
       Runfiles runfiles,
       @Nullable Artifact manifest,
+      @Nullable Artifact repoMappingManifest,
       boolean buildRunfileLinks,
       boolean runfileLinksEnabled) {
     this(
         runfilesDir,
         runfiles,
         /*runfilesCachingEnabled=*/ false,
         manifest,
+        repoMappingManifest,
         buildRunfileLinks,
         runfileLinksEnabled);
   }
@@ -108,15 +115,19 @@ private SingleRunfilesSupplier(
       Runfiles runfiles,
       boolean runfilesCachingEnabled,
       @Nullable Artifact manifest,
+      @Nullable Artifact repoMappingManifest,
       boolean buildRunfileLinks,
       boolean runfileLinksEnabled) {
     this(
         runfilesDir,
         runfiles,
         runfilesCachingEnabled
-            ? new RunfilesCacher(runfiles)
-            : () -> runfiles.getRunfilesInputs(/*eventHandler=*/ null, /*location=*/ null),
+            ? new RunfilesCacher(runfiles, repoMappingManifest)
+            : () ->
+                runfiles.getRunfilesInputs(
+                    /*eventHandler=*/ null, /*location=*/ null, repoMappingManifest),
         manifest,
+        repoMappingManifest,
         buildRunfileLinks,
         runfileLinksEnabled);
   }
@@ -126,13 +137,15 @@ private SingleRunfilesSupplier(
       Runfiles runfiles,
       Supplier<Map<PathFragment, Artifact>> runfilesInputs,
       @Nullable Artifact manifest,
+      @Nullable Artifact repoMappingManifest,
       boolean buildRunfileLinks,
       boolean runfileLinksEnabled) {
     checkArgument(!runfilesDir.isAbsolute());
     this.runfilesDir = checkNotNull(runfilesDir);
     this.runfiles = checkNotNull(runfiles);
     this.runfilesInputs = checkNotNull(runfilesInputs);
     this.manifest = manifest;
+    this.repoMappingManifest = repoMappingManifest;
     this.buildRunfileLinks = buildRunfileLinks;
     this.runfileLinksEnabled = runfileLinksEnabled;
   }
@@ -199,17 +212,21 @@ public SingleRunfilesSupplier withOverriddenRunfilesDir(PathFragment newRunfiles
             runfiles,
             runfilesInputs,
             manifest,
+            repoMappingManifest,
             buildRunfileLinks,
             runfileLinksEnabled);
   }
 
   /** Softly caches the result of {@link Runfiles#getRunfilesInputs}. */
   private static final class RunfilesCacher implements Supplier<Map<PathFragment, Artifact>> {
+
     private final Runfiles runfiles;
+    @Nullable private final Artifact repoMappingManifest;
     private volatile SoftReference<Map<PathFragment, Artifact>> ref = new SoftReference<>(null);
 
-    RunfilesCacher(Runfiles runfiles) {
+    RunfilesCacher(Runfiles runfiles, @Nullable Artifact repoMappingManifest) {
       this.runfiles = runfiles;
+      this.repoMappingManifest = repoMappingManifest;
     }
 
     @Override
@@ -221,7 +238,9 @@ public Map<PathFragment, Artifact> get() {
       synchronized (this) {
         result = ref.get();
         if (result == null) {
-          result = runfiles.getRunfilesInputs(/*eventHandler=*/ null, /*location=*/ null);
+          result =
+              runfiles.getRunfilesInputs(
+                  /*eventHandler=*/ null, /*location=*/ null, repoMappingManifest);
           ref = new SoftReference<>(result);
         }
       }

src/main/java/com/google/devtools/build/lib/analysis/SourceManifestAction.java

@@ -61,7 +61,7 @@ public final class SourceManifestAction extends AbstractFileWriteAction {
 
   private static final Comparator<Map.Entry<PathFragment, Artifact>> ENTRY_COMPARATOR =
       (path1, path2) -> path1.getKey().getPathString().compareTo(path2.getKey().getPathString());
-
+  private final Artifact repoMappingManifest;
   /**
    * Interface for defining manifest formatting and reporting specifics. Implementations must be
    * immutable.
@@ -118,7 +118,7 @@ void writeEntry(
   @VisibleForTesting
   SourceManifestAction(
       ManifestWriter manifestWriter, ActionOwner owner, Artifact primaryOutput, Runfiles runfiles) {
-    this(manifestWriter, owner, primaryOutput, runfiles, /*remotableSourceManifestActions=*/ false);
+    this(manifestWriter, owner, primaryOutput, runfiles, null, false);
   }
 
   /**
@@ -129,17 +129,20 @@ void writeEntry(
    * @param owner the action owner
    * @param primaryOutput the file to which to write the manifest
    * @param runfiles runfiles
+   * @param repoMappingManifest the repository mapping manifest for runfiles
    */
   public SourceManifestAction(
       ManifestWriter manifestWriter,
       ActionOwner owner,
       Artifact primaryOutput,
       Runfiles runfiles,
+      @Nullable Artifact repoMappingManifest,
       boolean remotableSourceManifestActions) {
     // The real set of inputs is computed in #getInputs().
     super(owner, NestedSetBuilder.emptySet(Order.STABLE_ORDER), primaryOutput, false);
     this.manifestWriter = manifestWriter;
     this.runfiles = runfiles;
+    this.repoMappingManifest = repoMappingManifest;
     this.remotableSourceManifestActions = remotableSourceManifestActions;
   }
 
@@ -180,7 +183,9 @@ public synchronized NestedSet<Artifact> getInputs() {
   @VisibleForTesting
   public void writeOutputFile(OutputStream out, @Nullable EventHandler eventHandler)
       throws IOException {
-    writeFile(out, runfiles.getRunfilesInputs(eventHandler, getOwner().getLocation()));
+    writeFile(
+        out,
+        runfiles.getRunfilesInputs(eventHandler, getOwner().getLocation(), repoMappingManifest));
   }
 
   /**
@@ -202,7 +207,8 @@ public String getStarlarkContent() throws IOException {
   @Override
   public DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) {
     final Map<PathFragment, Artifact> runfilesInputs =
-        runfiles.getRunfilesInputs(ctx.getEventHandler(), getOwner().getLocation());
+        runfiles.getRunfilesInputs(
+            ctx.getEventHandler(), getOwner().getLocation(), repoMappingManifest);
     return out -> writeFile(out, runfilesInputs);
   }
 
@@ -247,6 +253,10 @@ protected void computeKey(
     fp.addString(GUID);
     fp.addBoolean(remotableSourceManifestActions);
     runfiles.fingerprint(fp);
+    fp.addBoolean(repoMappingManifest != null);
+    if (repoMappingManifest != null) {
+      fp.addPath(repoMappingManifest.getExecPath());
+    }
   }
 
   @Override

src/main/java/com/google/devtools/build/lib/analysis/actions/SymlinkTreeAction.java

@@ -49,6 +49,7 @@ public final class SymlinkTreeAction extends AbstractAction {
   private final boolean enableRunfiles;
   private final boolean inprocessSymlinkCreation;
   private final boolean skipRunfilesManifests;
+  private final Artifact repoMappingManifest;
 
   /**
    * Creates SymlinkTreeAction instance.
@@ -59,6 +60,7 @@ public final class SymlinkTreeAction extends AbstractAction {
    * @param runfiles the input runfiles
    * @param outputManifest the generated symlink tree manifest (must have "MANIFEST" base name).
    *     Symlink tree root will be set to the artifact's parent directory.
+   * @param repoMappingManifest the repository mapping manifest
    * @param filesetRoot non-null if this is a fileset symlink tree
    */
   public SymlinkTreeAction(
@@ -67,12 +69,14 @@ public SymlinkTreeAction(
       Artifact inputManifest,
       @Nullable Runfiles runfiles,
       Artifact outputManifest,
+      @Nullable Artifact repoMappingManifest,
       String filesetRoot) {
     this(
         owner,
         inputManifest,
         runfiles,
         outputManifest,
+        repoMappingManifest,
         filesetRoot,
         config.getActionEnvironment(),
         config.runfilesEnabled(),
@@ -90,21 +94,24 @@ public SymlinkTreeAction(
    * @param runfiles the input runfiles
    * @param outputManifest the generated symlink tree manifest (must have "MANIFEST" base name).
    *     Symlink tree root will be set to the artifact's parent directory.
+   * @param repoMappingManifest the repository mapping manifest
    * @param filesetRoot non-null if this is a fileset symlink tree,
    */
   public SymlinkTreeAction(
       ActionOwner owner,
       Artifact inputManifest,
       @Nullable Runfiles runfiles,
       Artifact outputManifest,
+      @Nullable Artifact repoMappingManifest,
       @Nullable String filesetRoot,
       ActionEnvironment env,
       boolean enableRunfiles,
       boolean inprocessSymlinkCreation,
       boolean skipRunfilesManifests) {
     super(
         owner,
-        computeInputs(enableRunfiles, skipRunfilesManifests, runfiles, inputManifest),
+        computeInputs(
+            enableRunfiles, skipRunfilesManifests, runfiles, inputManifest, repoMappingManifest),
         ImmutableSet.of(outputManifest),
         env);
     Preconditions.checkArgument(outputManifest.getPath().getBaseName().equals("MANIFEST"));
@@ -118,13 +125,15 @@ public SymlinkTreeAction(
     this.inprocessSymlinkCreation = inprocessSymlinkCreation;
     this.skipRunfilesManifests = skipRunfilesManifests && enableRunfiles && (filesetRoot == null);
     this.inputManifest = this.skipRunfilesManifests ? null : inputManifest;
+    this.repoMappingManifest = repoMappingManifest;
   }
 
   private static NestedSet<Artifact> computeInputs(
       boolean enableRunfiles,
       boolean skipRunfilesManifests,
       Runfiles runfiles,
-      Artifact inputManifest) {
+      Artifact inputManifest,
+      @Nullable Artifact repoMappingManifest) {
     NestedSetBuilder<Artifact> inputs = NestedSetBuilder.<Artifact>stableOrder();
     if (!skipRunfilesManifests || !enableRunfiles || runfiles == null) {
       inputs.add(inputManifest);
@@ -134,6 +143,9 @@ private static NestedSet<Artifact> computeInputs(
     // existing, so directory or file links can be made as appropriate.
     if (enableRunfiles && runfiles != null && OS.getCurrent() == OS.WINDOWS) {
       inputs.addTransitive(runfiles.getAllArtifacts());
+      if (repoMappingManifest != null) {
+        inputs.add(repoMappingManifest);
+      }
     }
     return inputs.build();
   }
@@ -151,6 +163,11 @@ public Artifact getOutputManifest() {
     return outputManifest;
   }
 
+  @Nullable
+  public Artifact getRepoMappingManifest() {
+    return repoMappingManifest;
+  }
+
   public boolean isFilesetTree() {
     return filesetRoot != null;
   }
@@ -201,6 +218,10 @@ protected void computeKey(
     if (runfiles != null) {
       runfiles.fingerprint(fp);
     }
+    fp.addBoolean(repoMappingManifest != null);
+    if (repoMappingManifest != null) {
+      fp.addPath(repoMappingManifest.getExecPath());
+    }
   }
 
   @Override

src/main/java/com/google/devtools/build/lib/analysis/test/TestActionBuilder.java

@@ -379,6 +379,7 @@ private TestParams createTestAction(int shards)
           SingleRunfilesSupplier.createCaching(
               runfilesSupport.getRunfilesDirectoryExecPath(),
               runfilesSupport.getRunfiles(),
+              runfilesSupport.getRepoMappingManifest(),
               runfilesSupport.isBuildRunfileLinks(),
               runfilesSupport.isRunfilesEnabled());
     } else {