Create a AOSP Bazel overlay workspace with Soong
The Bazel overlay is a directory at out/soong/bazel_overlay that
replicates the layout of the AOSP Soong module tree, but as a Bazel
workspace. Each Soong module variant is represented as a BUILD target
created with the `soong_module` rule.
To create this overlay, run `m bazel_overlay`.
A `soong_module` target can depend on other `soong_module` targets.
These dependencies replicate each module's `directDeps` in the Blueprint
graph, just before `PrepareBuildActions`.
This enables users to use bazel query as a way to introspect the Soong
module graph. For example,
- Direct reverse dependencies of //bionic/libc:generated_android_ids in
//bionic/libc/...:
$ bazel query 'rdeps(//bionic/libc/...,
//bionic/libc:generated_android_ids, 1)'
//bionic/libc:libc_bionic_ndk--android_recovery_arm_armv7-a-neon_static
//bionic/libc:libc_bionic_ndk--android_ramdisk_arm_armv7-a-neon_static
//bionic/libc:libc_bionic_ndk--android_arm_armv7-a-neon_static_com.android.runtime
//bionic/libc:libc_bionic_ndk--android_arm_armv7-a-neon_static
//bionic/libc:generated_android_ids
- Why does com.android.runtime depend on lzma?
$ bazel query
'somepath(//bionic/apex:com.android.runtime--android_common_com.android.runtime_image,
//external/lzma/...)'
//bionic/apex:com.android.runtime--android_common_com.android.runtime_image
//bionic/libc/malloc_debug:libc_malloc_debug--android_arm_armv7-a-neon_shared_com.android.runtime
//system/core/libunwindstack:libunwindstack--android_arm_armv7-a-neon_shared_com.android.runtime
//external/lzma/C:liblzma--android_arm_armv7-a-neon_shared_com.android.runtime
- What does the dep graph of //bionic/libc:crtbegin_so look like?
$ bazel query
'deps(//bionic/libc:crtbegin_so--android_arm_armv7-a-neon)'
--output=graph > graph.in && dot -Tpng < graph.in > graph.png
https://photos.app.goo.gl/DfsdoFRNsRjGwTmy8
Test: croot && m bazel_overlay && cd out/soong/bazel_overlay && bazel
query //... && bazel query 'rdeps(//bionic/libc/...,
//bionic/libc:generated_android_ids, 1)'
Signed-off-by: Jingwen Chen <jingwen@google.com>
Change-Id: I3bf40309bfb2d963bb8a688706385a57ee304c37#
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index 532d9e4..01a39a2 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -26,11 +26,13 @@
)
var (
- docFile string
+ docFile string
+ bazelOverlayDir string
)
func init() {
flag.StringVar(&docFile, "soong_docs", "", "build documentation file to output")
+ flag.StringVar(&bazelOverlayDir, "bazel_overlay_dir", "", "path to the bazel overlay directory")
}
func newNameResolver(config android.Config) *android.NameResolver {
@@ -65,7 +67,7 @@
os.Exit(1)
}
- if docFile != "" {
+ if !shouldPrepareBuildActions() {
configuration.SetStopBefore(bootstrap.StopBeforePrepareBuildActions)
}
@@ -85,6 +87,13 @@
bootstrap.Main(ctx.Context, configuration, extraNinjaDeps...)
+ if bazelOverlayDir != "" {
+ if err := createBazelOverlay(ctx, bazelOverlayDir); err != nil {
+ fmt.Fprintf(os.Stderr, "%s", err)
+ os.Exit(1)
+ }
+ }
+
if docFile != "" {
if err := writeDocs(ctx, docFile); err != nil {
fmt.Fprintf(os.Stderr, "%s", err)
@@ -94,7 +103,7 @@
// TODO(ccross): make this a command line argument. Requires plumbing through blueprint
// to affect the command line of the primary builder.
- if docFile == "" {
+ if shouldPrepareBuildActions() {
metricsFile := filepath.Join(bootstrap.BuildDir, "soong_build_metrics.pb")
err = android.WriteMetrics(configuration, metricsFile)
if err != nil {
@@ -103,3 +112,9 @@
}
}
}
+
+func shouldPrepareBuildActions() bool {
+ // If we're writing soong_docs or bazel_overlay, don't write build.ninja or
+ // collect metrics.
+ return docFile == "" && bazelOverlayDir == ""
+}