From 50cb6a49ad984e72b68a6031086db42d35bd05ec Mon Sep 17 00:00:00 2001
From: Fabian Meumertzheim <fabian@meumertzhe.im>
Date: Wed, 1 Nov 2023 21:49:42 -0700
Subject: [PATCH] Expose repo mapping manifest to Starlark

The new `repo_mapping_manifest` field on `FilesToRunProvider` allows Starlark rule implementations to access the `File` containing the repo mapping manifest for an executable target, e.g. to include the manifest into a synthetic runfiles structure for packaging purposes.

Fixes #19937

Closes #19944.

PiperOrigin-RevId: 578735848
Change-Id: Ida78778af5aef4ba0c216815563aef4b54c9d1db
---
 .../lib/analysis/FilesToRunProvider.java      |  7 +++++
 .../FilesToRunProviderApi.java                |  8 ++++++
 .../RunfilesRepoMappingManifestTest.java      | 26 +++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
index ee5a12ae32a568..f07c201aede21a 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/FilesToRunProvider.java
@@ -95,6 +95,13 @@ public final Artifact getRunfilesManifest() {
     return runfilesSupport != null ? runfilesSupport.getRunfilesManifest() : null;
   }
 
+  @Nullable
+  @Override
+  public Artifact getRepoMappingManifest() {
+    var runfilesSupport = getRunfilesSupport();
+    return runfilesSupport != null ? runfilesSupport.getRepoMappingManifest() : null;
+  }
+
   /** Returns a {@link RunfilesSupplier} encapsulating runfiles for this tool. */
   public final RunfilesSupplier getRunfilesSupplier() {
     return firstNonNull(getRunfilesSupport(), EmptyRunfilesSupplier.INSTANCE);
diff --git a/src/main/java/com/google/devtools/build/lib/starlarkbuildapi/FilesToRunProviderApi.java b/src/main/java/com/google/devtools/build/lib/starlarkbuildapi/FilesToRunProviderApi.java
index 7dab417d98e9e4..5c0006bf053905 100644
--- a/src/main/java/com/google/devtools/build/lib/starlarkbuildapi/FilesToRunProviderApi.java
+++ b/src/main/java/com/google/devtools/build/lib/starlarkbuildapi/FilesToRunProviderApi.java
@@ -39,4 +39,12 @@ public interface FilesToRunProviderApi<FileT extends FileApi> extends StarlarkVa
       allowReturnNones = true)
   @Nullable
   FileT getRunfilesManifest();
+
+  @StarlarkMethod(
+      name = "repo_mapping_manifest",
+      doc = "The repo mapping manifest or None if it does not exist.",
+      structField = true,
+      allowReturnNones = true)
+  @Nullable
+  FileT getRepoMappingManifest();
 }
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/RunfilesRepoMappingManifestTest.java b/src/test/java/com/google/devtools/build/lib/analysis/RunfilesRepoMappingManifestTest.java
index e7949ebee49215..21cd1832c3ba50 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/RunfilesRepoMappingManifestTest.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/RunfilesRepoMappingManifestTest.java
@@ -391,6 +391,32 @@ public void hasMappingForSymlinks() throws Exception {
         .inOrder();
   }
 
+  @Test
+  public void repoMappingOnFilesToRunProvider() throws Exception {
+    scratch.overwriteFile("MODULE.bazel", "bazel_dep(name='bare_rule',version='1.0')");
+    scratch.overwriteFile(
+        "defs.bzl",
+        "def _get_repo_mapping_impl(ctx):",
+        "    files_to_run = ctx.attr.bin[DefaultInfo].files_to_run",
+        "    return [",
+        "        DefaultInfo(files = depset([files_to_run.repo_mapping_manifest])),",
+        "    ]",
+        "get_repo_mapping = rule(",
+        "    implementation = _get_repo_mapping_impl,",
+        "    attrs = {'bin':attr.label(cfg='target',executable=True)}",
+        ")");
+    scratch.overwriteFile(
+        "BUILD",
+        "load('@bare_rule//:defs.bzl', 'bare_binary')",
+        "load('//:defs.bzl', 'get_repo_mapping')",
+        "bare_binary(name='aaa')",
+        "get_repo_mapping(name='get_repo_mapping', bin=':aaa')");
+    invalidatePackages();
+
+    assertThat(getFilesToBuild(getConfiguredTarget("//:get_repo_mapping")).toList())
+        .containsExactly(getRunfilesSupport("//:aaa").getRepoMappingManifest());
+  }
+
   /**
    * Similar to {@link BuildViewTestCase#rewriteWorkspace(String...)}, but does not call {@link
    * BuildViewTestCase#invalidatePackages()}.