Add a trace_references_from dex optimization property
Introduce a new property `trace_references_from` in the optimize block.
This field allows specifying a set of downstream targets from which to
trace references when optimizing the current target.
In practice, this requires explicit breaking of any cycles that might
occur. A follow-up effort will explore doing this dynamically and
implicitly for `libs` references onto an optimized target that
enables this feature.
Bug: 212737576
Test: m nothing
Test: go test ./java
Flag: EXEMPT bugfix
Change-Id: I088bd8bf89403661a084a43b2822a6efbbc0294d
diff --git a/java/base.go b/java/base.go
index 0833831..d49a9bc 100644
--- a/java/base.go
+++ b/java/base.go
@@ -888,6 +888,10 @@
// Add dependency on libraries that provide additional hidden api annotations.
ctx.AddVariationDependencies(nil, hiddenApiAnnotationsTag, j.properties.Hiddenapi_additional_annotations...)
+ // Add dependency on (soft) downstream libs from which to trace references during optimization.
+ traceRefs := j.dexProperties.Optimize.Trace_references_from.GetOrDefault(ctx, []string{})
+ ctx.AddVariationDependencies(nil, traceReferencesTag, traceRefs...)
+
// For library dependencies that are component libraries (like stubs), add the implementation
// as a dependency (dexpreopt needs to be against the implementation library, not stubs).
for _, dep := range libDeps {
diff --git a/java/dex.go b/java/dex.go
index b32d5ae..ed9c82b 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -116,6 +116,21 @@
//
// By default all classes are compiled using R8 when Optimize.Enabled is set.
Exclude *string `android:"path"`
+
+ // Optional list of downstream (Java) libraries from which to trace and preserve references
+ // when optimizing. Note that this requires that the source reference does *not* have
+ // a strict lib dependency on this target; dependencies should be on intermediate targets
+ // statically linked into this target, e.g., if A references B, and we want to trace and
+ // keep references from A when optimizing B, you would create an intermediate B.impl (
+ // containing all static code), have A depend on `B.impl` via libs, and set
+ // `trace_references_from: ["A"]` on B.
+ //
+ // Also note that these are *not* inherited across targets, they must be specified at the
+ // top-level target that is optimized.
+ //
+ // TODO(b/212737576): Handle this implicitly using bottom-up deps mutation and implicit
+ // creation of a proxy `.impl` library.
+ Trace_references_from proptools.Configurable[[]string] `android:"arch_variant"`
}
// Keep the data uncompressed. We always need uncompressed dex for execution,
@@ -458,6 +473,20 @@
flagFiles = append(flagFiles, android.PathsForModuleSrc(ctx, opt.Proguard_flags_files)...)
+ traceReferencesSources := android.Paths{}
+ ctx.VisitDirectDepsProxyWithTag(traceReferencesTag, func(m android.ModuleProxy) {
+ if dep, ok := android.OtherModuleProvider(ctx, m, JavaInfoProvider); ok {
+ traceReferencesSources = append(traceReferencesSources, dep.ImplementationJars...)
+ }
+ })
+ if len(traceReferencesSources) > 0 {
+ traceTarget := dexParams.classesJar
+ traceLibs := android.FirstUniquePaths(append(flags.bootClasspath.Paths(), flags.dexClasspath.Paths()...))
+ traceReferencesFlags := android.PathForModuleOut(ctx, "proguard", "trace_references.flags")
+ TraceReferences(ctx, traceReferencesSources, traceTarget, traceLibs, traceReferencesFlags)
+ flagFiles = append(flagFiles, traceReferencesFlags)
+ }
+
flagFiles = android.FirstUniquePaths(flagFiles)
r8Flags = append(r8Flags, android.JoinWithPrefix(flagFiles.Strings(), "-include "))
diff --git a/java/dex_test.go b/java/dex_test.go
index 66d801d..e94864b 100644
--- a/java/dex_test.go
+++ b/java/dex_test.go
@@ -866,3 +866,46 @@
})
}
}
+
+func TestTraceReferences(t *testing.T) {
+ t.Parallel()
+ bp := `
+ android_app {
+ name: "app",
+ libs: ["lib.impl"],
+ srcs: ["foo.java"],
+ platform_apis: true,
+ }
+
+ java_library {
+ name: "lib",
+ optimize: {
+ enabled: true,
+ trace_references_from: ["app"],
+ },
+ srcs: ["bar.java"],
+ static_libs: ["lib.impl"],
+ installable: true,
+ }
+
+ java_library {
+ name: "lib.impl",
+ srcs: ["baz.java"],
+ }
+ `
+ result := android.GroupFixturePreparers(
+ PrepareForTestWithJavaDefaultModules,
+ ).RunTestWithBp(t, bp)
+
+ appJar := result.ModuleForTests(t, "app", "android_common").Output("combined/app.jar").Output
+ libJar := result.ModuleForTests(t, "lib", "android_common").Output("combined/lib.jar").Output
+ libTraceRefs := result.ModuleForTests(t, "lib", "android_common").Rule("traceReferences")
+ libR8 := result.ModuleForTests(t, "lib", "android_common").Rule("r8")
+
+ android.AssertStringDoesContain(t, "expected trace reference source from app jar",
+ libTraceRefs.Args["sources"], "--source "+appJar.String())
+ android.AssertStringEquals(t, "expected trace reference target into lib jar",
+ libJar.String(), libTraceRefs.Input.String())
+ android.AssertStringDoesContain(t, "expected trace reference proguard flags in lib r8 flags",
+ libR8.Args["r8Flags"], "trace_references.flags")
+}
diff --git a/java/dexpreopt.go b/java/dexpreopt.go
index b21cfc9..e8e1cd4 100644
--- a/java/dexpreopt.go
+++ b/java/dexpreopt.go
@@ -650,6 +650,9 @@
// for now just exclude any known irrelevant dependencies that would lead to incorrect errors.
if _, ok := tag.(bootclasspathDependencyTag); ok {
return false
+ } else if tag == traceReferencesTag {
+ // Allow ordering inversion if the dependency is purely for tracing references.
+ return false
}
depIndex := jars.IndexOfJar(dep.Name())
if jarIndex < depIndex && !config.BrokenSuboptimalOrderOfSystemServerJars {
diff --git a/java/java.go b/java/java.go
index 215fbbd..372e043 100644
--- a/java/java.go
+++ b/java/java.go
@@ -578,6 +578,7 @@
extraLintCheckTag = dependencyTag{name: "extra-lint-check", toolchain: true}
jniLibTag = dependencyTag{name: "jnilib", runtimeLinked: true}
r8LibraryJarTag = dependencyTag{name: "r8-libraryjar", runtimeLinked: true}
+ traceReferencesTag = dependencyTag{name: "trace-references"}
syspropPublicStubDepTag = dependencyTag{name: "sysprop public stub"}
javaApiContributionTag = dependencyTag{name: "java-api-contribution"}
aconfigDeclarationTag = dependencyTag{name: "aconfig-declaration"}
@@ -608,6 +609,7 @@
kotlinPluginTag,
syspropPublicStubDepTag,
instrumentationForTag,
+ traceReferencesTag,
}
)