Add test_for property

This change adds 'test_for' property to cc_test_* types. The property is
used to mark a module as a test for one or more APEXes, in which case
the module has accecss to the private part of the listed APEXes. For
example, the module is linked with the actrual shared library in the
APEX instead of the stub of the shared library.

Exempt-From-Owner-Approval: already +2'ed by owner

Bug: 129539670
Bug: 153046163
Test: m
Change-Id: I45ed0d7a15540b0d69b2a3b8d9c4cb202adff6f2
diff --git a/android/apex.go b/android/apex.go
index 839a03a..398fbae 100644
--- a/android/apex.go
+++ b/android/apex.go
@@ -108,6 +108,11 @@
 
 	// Tests if the module comes from an updatable APEX.
 	Updatable() bool
+
+	// List of APEXes that this module tests. The module has access to
+	// the private part of the listed APEXes even when it is not included in the
+	// APEXes.
+	TestFor() []string
 }
 
 type ApexProperties struct {
@@ -151,6 +156,11 @@
 	return m.ApexProperties.Apex_available
 }
 
+func (m *ApexModuleBase) TestFor() []string {
+	// To be implemented by concrete types inheriting ApexModuleBase
+	return nil
+}
+
 func (m *ApexModuleBase) BuildForApexes(apexes []ApexInfo) {
 	m.apexVariationsLock.Lock()
 	defer m.apexVariationsLock.Unlock()
diff --git a/apex/apex_test.go b/apex/apex_test.go
index b1e7bc9..8807d00 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -4533,6 +4533,58 @@
 	testNoUpdatableJarsInBootImage(t, "", bp, transform)
 }
 
+func TestTestFor(t *testing.T) {
+	ctx, _ := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			native_shared_libs: ["mylib", "myprivlib"],
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		cc_library {
+			name: "mylib",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			stl: "none",
+			stubs: {
+				versions: ["1"],
+			},
+			apex_available: ["myapex"],
+		}
+
+		cc_library {
+			name: "myprivlib",
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			stl: "none",
+			apex_available: ["myapex"],
+		}
+
+
+		cc_test {
+			name: "mytest",
+			gtest: false,
+			srcs: ["mylib.cpp"],
+			system_shared_libs: [],
+			stl: "none",
+			shared_libs: ["mylib", "myprivlib"],
+			test_for: ["myapex"]
+		}
+	`)
+
+	// the test 'mytest' is a test for the apex, therefore is linked to the
+	// actual implementation of mylib instead of its stub.
+	ldFlags := ctx.ModuleForTests("mytest", "android_arm64_armv8-a").Rule("ld").Args["libFlags"]
+	ensureContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared/mylib.so")
+	ensureNotContains(t, ldFlags, "mylib/android_arm64_armv8-a_shared_1/mylib.so")
+}
+
 func TestMain(m *testing.M) {
 	run := func() int {
 		setUp()
diff --git a/cc/cc.go b/cc/cc.go
index 24173ee..66425c7 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -2338,6 +2338,15 @@
 						// always link to non-stub variant
 						useThisDep = !depIsStubs
 					}
+					for _, testFor := range c.TestFor() {
+						// Another exception: if this module is bundled with an APEX, then
+						// it is linked with the non-stub variant of a module in the APEX
+						// as if this is part of the APEX.
+						if android.DirectlyInApex(testFor, depName) {
+							useThisDep = !depIsStubs
+							break
+						}
+					}
 				} else {
 					// If building for APEX, use stubs only when it is not from
 					// the same APEX
@@ -2764,6 +2773,16 @@
 	}
 }
 
+func (c *Module) TestFor() []string {
+	if test, ok := c.linker.(interface {
+		testFor() []string
+	}); ok {
+		return test.testFor()
+	} else {
+		return c.ApexModuleBase.TestFor()
+	}
+}
+
 // Return true if the module is ever installable.
 func (c *Module) EverInstallable() bool {
 	return c.installer != nil &&
diff --git a/cc/test.go b/cc/test.go
index 1085d3a..f51cf01 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -29,6 +29,11 @@
 
 	// if set, use the isolated gtest runner. Defaults to false.
 	Isolated *bool
+
+	// List of APEXes that this module tests. The module has access to
+	// the private part of the listed APEXes even when it is not included in the
+	// APEXes.
+	Test_for []string
 }
 
 // Test option struct.
@@ -215,6 +220,10 @@
 	return BoolDefault(test.Properties.Gtest, true)
 }
 
+func (test *testDecorator) testFor() []string {
+	return test.Properties.Test_for
+}
+
 func (test *testDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 	if !test.gtest() {
 		return flags