Remove a self-dependency of bp2build
bp2build (i.e. bootstrap.ninja#bp2build_workspace_marker) generate $OUT/soong/bp2build/**/BUILD.bazel files
Having them as a dependency would thus make bp2build_workspace_marker stale upon incremental builds (because we don't re-touch the marker file if it already exists)
See Also: https://android-review.googlesource.com/c/platform/build/soong/+/2263423
Bug: b/253450880
Test: NINJA_ARGS='-d explain' m --bazel-mode adbd
repeat and see if bp2build is rerun
prior to this CL, one would see the input /usr/local/google/home/usta/aosp/out/soong/bp2build/build/make/tools/BUILD.bazel trigger bp2build over and over again
Change-Id: I904cd333a5d6ef506fc4019eda7623ef96a1daa3
diff --git a/bp2build/symlink_forest.go b/bp2build/symlink_forest.go
index 63b6e9e..092b240 100644
--- a/bp2build/symlink_forest.go
+++ b/bp2build/symlink_forest.go
@@ -278,17 +278,9 @@
// Neither is a directory. Merge them.
srcBuildFile := shared.JoinPath(topdir, srcChild)
generatedBuildFile := shared.JoinPath(topdir, buildFilesChild)
- // Add the src and generated build files as dependencies so that bp2build
- // is rerun when they change. Currently, this is only really necessary
- // for srcBuildFile, because if we regenerate the generated build files
- // we will always rerun the symlink forest generation as well. If that
- // is later split up into separate, fully dependency-tracing steps, then
- // we'll need srcBuildFile as well. Adding srcBuildFile here today
- // technically makes it a dependency of bp2build_workspace_marker, which
- // also implicitly outputs that file, but since bp2build_workspace_marker
- // will always have a newer timestamp than the generatedBuildFile it
- // shouldn't be a problem.
- *acc = append(*acc, srcBuildFile, generatedBuildFile)
+ // The Android.bp file that codegen used to produce `buildFilesChild` is
+ // already a dependency, we can ignore `buildFilesChild`.
+ *acc = append(*acc, srcChild)
err = mergeBuildFiles(shared.JoinPath(topdir, forestChild), srcBuildFile, generatedBuildFile, cfg.IsEnvTrue("BP2BUILD_VERBOSE"))
if err != nil {
fmt.Fprintf(os.Stderr, "Error merging %s and %s: %s",