Add srcjar output for platform_bootclasspath

This output contains all the transitive sources that are contained in
the bootclasspath.

It's currently limited to source-built bootclasspath components. Future
work will make this deal with sdk_library prebuilts.

Bug: 151360309
Test: unit test, as well as manual inspection of platform-bootclasspath
Change-Id: Ie05d8125e19736d8b4b9ebafb70b88a0a40069d5
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index ade7395..bab0bf6 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -173,6 +173,18 @@
 	allModules = append(allModules, apexModules...)
 	b.configuredModules = allModules
 
+	var transitiveSrcFiles android.Paths
+	for _, module := range allModules {
+		depInfo := ctx.OtherModuleProvider(module, JavaInfoProvider).(JavaInfo)
+		if depInfo.TransitiveSrcFiles != nil {
+			transitiveSrcFiles = append(transitiveSrcFiles, depInfo.TransitiveSrcFiles.ToList()...)
+		}
+	}
+	jarArgs := resourcePathsToJarArgs(transitiveSrcFiles)
+	jarArgs = append(jarArgs, "-srcjar") // Move srcfiles to the right package
+	transitiveSrcJar := android.PathForModuleOut(ctx, ctx.ModuleName()+"-transitive.srcjar")
+	TransformResourcesToJar(ctx, transitiveSrcJar, jarArgs, transitiveSrcFiles)
+
 	// Gather all the fragments dependencies.
 	b.fragments = gatherApexModulePairDepsWithTag(ctx, bootclasspathFragmentDepTag)
 
diff --git a/java/platform_bootclasspath_test.go b/java/platform_bootclasspath_test.go
index ff2da4b..37ff639 100644
--- a/java/platform_bootclasspath_test.go
+++ b/java/platform_bootclasspath_test.go
@@ -81,6 +81,15 @@
 			RunTest(t)
 	})
 
+	fooSourceSrc := "source/a.java"
+	barSrc := "a.java"
+
+	checkSrcJarInputs := func(t *testing.T, result *android.TestResult, name string, expected []string) {
+		t.Helper()
+		srcjar := result.ModuleForTests(name, "android_common").Output(name + "-transitive.srcjar")
+		android.AssertStringDoesContain(t, "srcjar arg", srcjar.Args["jarArgs"], "-srcjar")
+		android.AssertArrayString(t, "srcjar inputs", expected, srcjar.Implicits.Strings())
+	}
 	t.Run("source", func(t *testing.T) {
 		result := android.GroupFixturePreparers(
 			preparer,
@@ -91,6 +100,10 @@
 			"platform:foo",
 			"platform:bar",
 		})
+		checkSrcJarInputs(t, result, "platform-bootclasspath", []string{
+			fooSourceSrc,
+			barSrc,
+		})
 	})
 
 	t.Run("prebuilt", func(t *testing.T) {
@@ -103,6 +116,10 @@
 			"platform:prebuilt_foo",
 			"platform:bar",
 		})
+		checkSrcJarInputs(t, result, "platform-bootclasspath", []string{
+			// TODO(b/151360309): This should also have the srcs for prebuilt_foo
+			barSrc,
+		})
 	})
 
 	t.Run("source+prebuilt - source preferred", func(t *testing.T) {
@@ -116,6 +133,10 @@
 			"platform:foo",
 			"platform:bar",
 		})
+		checkSrcJarInputs(t, result, "platform-bootclasspath", []string{
+			fooSourceSrc,
+			barSrc,
+		})
 	})
 
 	t.Run("source+prebuilt - prebuilt preferred", func(t *testing.T) {
@@ -129,6 +150,10 @@
 			"platform:prebuilt_foo",
 			"platform:bar",
 		})
+		checkSrcJarInputs(t, result, "platform-bootclasspath", []string{
+			// TODO(b/151360309): This should also have the srcs for prebuilt_foo
+			barSrc,
+		})
 	})
 
 	t.Run("dex import", func(t *testing.T) {
@@ -146,6 +171,10 @@
 			"platform:prebuilt_foo",
 			"platform:bar",
 		})
+		checkSrcJarInputs(t, result, "platform-bootclasspath", []string{
+			// TODO(b/151360309): This should also have the srcs for prebuilt_foo
+			barSrc,
+		})
 	})
 }