From c6a5ebb9af3d3e114a055c566f9aca777263a945 Mon Sep 17 00:00:00 2001
From: Googler <wyv@google.com>
Date: Wed, 13 Dec 2023 01:09:24 -0800
Subject: [PATCH] Still generate a WORKSPACE file in repo rules if
 --enable_workspace is set

https://github.com/bazelbuild/bazel/commit/47e48a13563742473abdcaef46b7c4f222a86831 made it so that, after a repo rule finishes, we no longer generate an empty WORKSPACE file if one is not found at the repo root. (We generate a REPO.bazel file instead, which also marks the boundary of the repo just fine.) But some users actually expect a WORKSPACE file specifically, so this CL restores the behavior of creating an empty WORKSPACE file if --enable_workspace is set.

Note that neither WORKSPACE nor REPO.bazel is created if the repo rule logic creates any repo boundary file itself.

Fixes https://github.com/bazelbuild/bazel/issues/20498.

PiperOrigin-RevId: 590492936
Change-Id: I43bfc7bf79b3749f1fb02ce31be789d92c36a2c0
---
 .../starlark/StarlarkRepositoryFunction.java  |  5 +++++
 .../shell/bazel/starlark_repository_test.sh   | 22 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkRepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkRepositoryFunction.java
index 452d1efe634231..74f52360613611 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkRepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkRepositoryFunction.java
@@ -32,6 +32,7 @@
 import com.google.devtools.build.lib.packages.BazelStarlarkContext;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.SymbolGenerator;
+import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions;
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
@@ -355,6 +356,10 @@ private RepositoryDirectoryValue.Builder fetchInternal(
     if (!WorkspaceFileHelper.isValidRepoRoot(outputDirectory)) {
       try {
         FileSystemUtils.createEmptyFile(outputDirectory.getRelative(LabelConstants.REPO_FILE_NAME));
+        if (starlarkSemantics.getBool(BuildLanguageOptions.ENABLE_WORKSPACE)) {
+          FileSystemUtils.createEmptyFile(
+              outputDirectory.getRelative(LabelConstants.WORKSPACE_FILE_NAME));
+        }
       } catch (IOException e) {
         throw new RepositoryFunctionException(e, Transience.TRANSIENT);
       }
diff --git a/src/test/shell/bazel/starlark_repository_test.sh b/src/test/shell/bazel/starlark_repository_test.sh
index d44bf29840bf5d..d5008c47cd5dd4 100755
--- a/src/test/shell/bazel/starlark_repository_test.sh
+++ b/src/test/shell/bazel/starlark_repository_test.sh
@@ -2583,4 +2583,26 @@ EOF
   assert_contains '"Accept": "application/text"' "$headers"
 }
 
+function test_repo_boundary_files() {
+  create_new_workspace
+  cat > MODULE.bazel <<EOF
+r = use_repo_rule("//:r.bzl", "r")
+r(name = "r")
+EOF
+  touch BUILD
+  cat > r.bzl <<EOF
+def _r(rctx):
+  rctx.file("BUILD", "filegroup(name='r', srcs=glob(['*']))")
+r = repository_rule(_r)
+EOF
+
+  bazel query --noenable_workspace --output=build @r > output || fail "expected bazel to succeed"
+  assert_contains 'REPO.bazel' output
+  assert_not_contains 'WORKSPACE' output
+
+  bazel query --enable_workspace --output=build @r > output || fail "expected bazel to succeed"
+  assert_contains 'REPO.bazel' output
+  assert_contains 'WORKSPACE' output
+}
+
 run_suite "local repository tests"