jacoco libs dependency for instrumented libraries

On coverage builds, R8 will fail to properly optimize and fail the build
if ignore_warnings: false, because jacoco injects dependencies on
jacocoagent classes, but the jacocoagent library is not part of the
classpath libraries passed in to R8 in its arguments.

Instead we can add jacocoagent as a libs dependency for these modules so
that it will get pulled into the r8 flags.

Bug: 243903417
Test: add optimize.ignore_warnings: false to NetworkStackAppDefaults &&
  make SKIP_ABI_CHECKS=true PRODUCT=cf_x86_phone-userdebug \
  EMMA_INSTRUMENT=true EMMA_INSTRUMENT_FRAMEWORK=true \
  CLANG_COVERAGE=true COVERAGE_PATHS="" \
  TARGET_USERDATAIMAGE_PARTITION_SIZE=17179869184 \
  SKIP_BOOT_JARS_CHECK=true \
  NetworkStack
Change-Id: I71313b1fd35437ec52890f5c30b3fd1381c7c3d2

apex/apex_test.go

@@ -8846,6 +8846,16 @@ func TestApexJavaCoverage(t *testing.T) {
 		android.FixtureMergeEnv(map[string]string{
 			"EMMA_INSTRUMENT": "true",
 		}),
+		// need to mock jacocoagent here to satisfy dependency added for
+		// instrumented libraries at build time
+		android.FixtureAddFile("jacocoagent/Android.bp", []byte(`
+			java_library {
+				name: "jacocoagent",
+				srcs: ["Test.java"],
+				system_modules: "none",
+				sdk_version: "none",
+			}
+		`)),
 	).RunTest(t)
 
 	// Make sure jacoco ran on both mylib and mybootclasspathlib

java/base.go

@@ -169,6 +169,8 @@ type CommonProperties struct {
 		Output_params []string
 	}
 
+	// If true, then jacocoagent is automatically added as a libs dependency so that
+	// r8 will not strip instrumentation classes out of dexed libraries.
 	Instrument bool `blueprint:"mutated"`
 	// If true, then the module supports statically including the jacocoagent
 	// into the library.
@@ -787,6 +789,9 @@ func (j *Module) deps(ctx android.BottomUpMutatorContext) {
 	} else if j.shouldInstrumentStatic(ctx) {
 		ctx.AddVariationDependencies(nil, staticLibTag, "jacocoagent")
 	}
+	if j.shouldInstrument(ctx) {
+		ctx.AddVariationDependencies(nil, libTag, "jacocoagent")
+	}
 
 	if j.useCompose() {
 		ctx.AddVariationDependencies(ctx.Config().BuildOSCommonTarget.Variations(), kotlinPluginTag,

java/bootclasspath_fragment_test.go

@@ -96,10 +96,22 @@ func TestBootclasspathFragmentInconsistentArtConfiguration_ApexMixture(t *testin
 }
 
 func TestBootclasspathFragment_Coverage(t *testing.T) {
-	prepareForTestWithFrameworkCoverage := android.FixtureMergeEnv(map[string]string{
-		"EMMA_INSTRUMENT":           "true",
-		"EMMA_INSTRUMENT_FRAMEWORK": "true",
-	})
+	prepareForTestWithFrameworkCoverage := android.GroupFixturePreparers(
+		android.FixtureMergeEnv(map[string]string{
+			"EMMA_INSTRUMENT":           "true",
+			"EMMA_INSTRUMENT_FRAMEWORK": "true",
+		}),
+		// need to mock jacocoagent here to satisfy dependency added for
+		// instrumented libraries at build time
+		android.FixtureAddFile("jacocoagent/Android.bp", []byte(`
+			java_library {
+				name: "jacocoagent",
+				srcs: ["Test.java"],
+				system_modules: "none",
+				sdk_version: "none",
+			}
+		`)),
+	)
 
 	prepareWithBp := android.FixtureWithRootAndroidBp(`
 		bootclasspath_fragment {