Fix symlinks from APEX to partitions

Previously, the symlink optimization for APEXes assumed that the target
of the symlinks are in the system partition. The assumption however
doesn't hold always because the file that was added to the APEX might be
with system_ext_specific: true or vendor: true.

Bug: 265598720
Test: m nothing
Change-Id: Ieb9a6769320c0ec697a88c0cae977e7d65288362

android/module.go

@@ -502,6 +502,7 @@ type Module interface {
 	InstallInRoot() bool
 	InstallInVendor() bool
 	InstallForceOS() (*OsType, *ArchType)
+	PartitionTag(DeviceConfig) string
 	HideFromMake()
 	IsHideFromMake() bool
 	IsSkipInstall() bool

apex/apex.go

@@ -514,6 +514,7 @@ type apexFile struct {
 	// buildFile is put in the installDir inside the APEX.
 	builtFile  android.Path
 	installDir string
+	partition  string
 	customStem string
 	symlinks   []string // additional symlinks
 
@@ -553,6 +554,7 @@ func newApexFile(ctx android.BaseModuleContext, builtFile android.Path, androidM
 	}
 	if module != nil {
 		ret.moduleDir = ctx.OtherModuleDir(module)
+		ret.partition = module.PartitionTag(ctx.DeviceConfig())
 		ret.requiredModuleNames = module.RequiredModuleNames()
 		ret.targetRequiredModuleNames = module.TargetRequiredModuleNames()
 		ret.hostRequiredModuleNames = module.HostRequiredModuleNames()

apex/apex_test.go

@@ -7122,7 +7122,10 @@ func TestSymlinksFromApexToSystem(t *testing.T) {
 		cc_library {
 			name: "mylib",
 			srcs: ["mylib.cpp"],
-			shared_libs: ["myotherlib"],
+			shared_libs: [
+				"myotherlib",
+				"myotherlib_ext",
+			],
 			system_shared_libs: [],
 			stl: "none",
 			apex_available: [
@@ -7146,6 +7149,20 @@ func TestSymlinksFromApexToSystem(t *testing.T) {
 			min_sdk_version: "current",
 		}
 
+		cc_library {
+			name: "myotherlib_ext",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			system_ext_specific: true,
+			stl: "none",
+			apex_available: [
+				"myapex",
+				"myapex.updatable",
+				"//apex_available:platform",
+			],
+			min_sdk_version: "current",
+		}
+
 		java_library {
 			name: "myjar",
 			srcs: ["foo/bar/MyClass.java"],
@@ -7186,12 +7203,15 @@ func TestSymlinksFromApexToSystem(t *testing.T) {
 		t.Errorf("%q is not found", file)
 	}
 
-	ensureSymlinkExists := func(t *testing.T, files []fileInApex, file string) {
+	ensureSymlinkExists := func(t *testing.T, files []fileInApex, file string, target string) {
 		for _, f := range files {
 			if f.path == file {
 				if !f.isLink {
 					t.Errorf("%q is not a symlink", file)
 				}
+				if f.src != target {
+					t.Errorf("expected symlink target to be %q, got %q", target, f.src)
+				}
 				return
 			}
 		}
@@ -7205,23 +7225,27 @@ func TestSymlinksFromApexToSystem(t *testing.T) {
 	ensureRealfileExists(t, files, "javalib/myjar.jar")
 	ensureRealfileExists(t, files, "lib64/mylib.so")
 	ensureRealfileExists(t, files, "lib64/myotherlib.so")
+	ensureRealfileExists(t, files, "lib64/myotherlib_ext.so")
 
 	files = getFiles(t, ctx, "myapex.updatable", "android_common_myapex.updatable_image")
 	ensureRealfileExists(t, files, "javalib/myjar.jar")
 	ensureRealfileExists(t, files, "lib64/mylib.so")
 	ensureRealfileExists(t, files, "lib64/myotherlib.so")
+	ensureRealfileExists(t, files, "lib64/myotherlib_ext.so")
 
 	// For bundled build, symlink to the system for the non-updatable APEXes only
 	ctx = testApex(t, bp)
 	files = getFiles(t, ctx, "myapex", "android_common_myapex_image")
 	ensureRealfileExists(t, files, "javalib/myjar.jar")
 	ensureRealfileExists(t, files, "lib64/mylib.so")
-	ensureSymlinkExists(t, files, "lib64/myotherlib.so") // this is symlink
+	ensureSymlinkExists(t, files, "lib64/myotherlib.so", "/system/lib64/myotherlib.so")             // this is symlink
+	ensureSymlinkExists(t, files, "lib64/myotherlib_ext.so", "/system_ext/lib64/myotherlib_ext.so") // this is symlink
 
 	files = getFiles(t, ctx, "myapex.updatable", "android_common_myapex.updatable_image")
 	ensureRealfileExists(t, files, "javalib/myjar.jar")
 	ensureRealfileExists(t, files, "lib64/mylib.so")
-	ensureRealfileExists(t, files, "lib64/myotherlib.so") // this is a real file
+	ensureRealfileExists(t, files, "lib64/myotherlib.so")     // this is a real file
+	ensureRealfileExists(t, files, "lib64/myotherlib_ext.so") // this is a real file
 }
 
 func TestSymlinksFromApexToSystemRequiredModuleNames(t *testing.T) {

apex/builder.go

@@ -476,8 +476,7 @@ func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext) {
 		// Copy the built file to the directory. But if the symlink optimization is turned
 		// on, place a symlink to the corresponding file in /system partition instead.
 		if a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform() {
-			// TODO(jiyong): pathOnDevice should come from fi.module, not being calculated here
+			pathOnDevice := filepath.Join("/", fi.partition, fi.path())
-			pathOnDevice := filepath.Join("/system", fi.path())
 			copyCommands = append(copyCommands, "ln -sfn "+pathOnDevice+" "+destPath)
 		} else {
 			// Copy the file into APEX
@@ -941,8 +940,7 @@ func (a *apexBundle) buildFlattenedApex(ctx android.ModuleContext) {
 			dir := filepath.Join("apex", bundleName, fi.installDir)
 			installDir := android.PathForModuleInstall(ctx, dir)
 			if a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform() {
-				// TODO(jiyong): pathOnDevice should come from fi.module, not being calculated here
+				pathOnDevice := filepath.Join("/", fi.partition, fi.path())
-				pathOnDevice := filepath.Join("/system", fi.path())
 				installedSymlinks = append(installedSymlinks,
 					ctx.InstallAbsoluteSymlink(installDir, fi.stem(), pathOnDevice))
 			} else {