cc: Vendor modules should NOT derive its "SDK" level from VNDK

Although vendor modules can be built bundled, they are technially not
part of the "platform", as it cannot access platform libraries (system
partition) directly.
They can only link to a restricted set of platform libraries (LLNDK),
and access restricted set of APIs.
We used to derive the LLNDK API level from the VNDK version. However
after VNDK deprecation, there is no "VNDK version" anymore.
Instead we would just derive the value from platform SDK version:
* If building an in-development build, build vendor modules against the
  in-development "current" API level.
* If building a REL / Final build, vendor should target the latest
  stable API.

Bug: 320423828
Test: go test
Test: presubmit
Test: build and boot
Change-Id: I2c5ef6530e9046b2dcc282bc1f020d8a505eab15

android/config.go

@@ -1309,6 +1309,10 @@ func (c *config) VendorApiLevel() string {
 	return String(c.productVariables.VendorApiLevel)
 }
 
+func (c *config) VendorApiLevelFrozen() bool {
+	return c.productVariables.GetBuildFlagBool("RELEASE_BOARD_API_LEVEL_FROZEN")
+}
+
 func (c *deviceConfig) Arches() []Arch {
 	var arches []Arch
 	for _, target := range c.config.Targets[Android] {

cc/cc.go

@@ -1608,9 +1608,10 @@ func (ctx *moduleContextImpl) useSdk() bool {
 
 func (ctx *moduleContextImpl) sdkVersion() string {
 	if ctx.ctx.Device() {
-		if ctx.useVndk() {
+		config := ctx.ctx.Config()
+		if !config.IsVndkDeprecated() && ctx.useVndk() {
 			vndkVer := ctx.mod.VndkVersion()
-			if inList(vndkVer, ctx.ctx.Config().PlatformVersionActiveCodenames()) {
+			if inList(vndkVer, config.PlatformVersionActiveCodenames()) {
 				return "current"
 			}
 			return vndkVer
@@ -1628,6 +1629,17 @@ func (ctx *moduleContextImpl) minSdkVersion() string {
 	if ver == "apex_inherit" || ver == "" {
 		ver = ctx.sdkVersion()
 	}
+
+	if ctx.ctx.Device() {
+		config := ctx.ctx.Config()
+		if config.IsVndkDeprecated() && ctx.inVendor() {
+			// If building for vendor with final API, then use the latest _stable_ API as "current".
+			if config.VendorApiLevelFrozen() && (ver == "" || ver == "current") {
+				ver = config.PlatformSdkVersion().String()
+			}
+		}
+	}
+
 	// For crt objects, the meaning of min_sdk_version is very different from other types of
 	// module. For them, min_sdk_version defines the oldest version that the build system will
 	// create versioned variants for. For example, if min_sdk_version is 16, then sdk variant of

cc/cc_test.go

@@ -43,6 +43,7 @@ var prepareForCcTest = android.GroupFixturePreparers(
 	android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
 		variables.VendorApiLevel = StringPtr("202404")
 		variables.DeviceVndkVersion = StringPtr("current")
+		variables.KeepVndk = BoolPtr(true)
 		variables.Platform_vndk_version = StringPtr("29")
 	}),
 )
@@ -4843,3 +4844,43 @@ func TestImageVariantsWithoutVndk(t *testing.T) {
 	testDepWithVariant("vendor")
 	testDepWithVariant("product")
 }
+
+func TestVendorSdkVersionWithoutVndk(t *testing.T) {
+	t.Parallel()
+
+	bp := `
+		cc_library {
+			name: "libfoo",
+			srcs: ["libfoo.cc"],
+			vendor_available: true,
+		}
+
+		cc_library {
+			name: "libbar",
+			srcs: ["libbar.cc"],
+			vendor_available: true,
+			min_sdk_version: "29",
+		}
+	`
+
+	ctx := prepareForCcTestWithoutVndk.RunTestWithBp(t, bp)
+	testSdkVersionFlag := func(module, version string) {
+		flags := ctx.ModuleForTests(module, "android_vendor_arm64_armv8-a_static").Rule("cc").Args["cFlags"]
+		android.AssertStringDoesContain(t, "min sdk version", flags, "-target aarch64-linux-android"+version)
+	}
+
+	testSdkVersionFlag("libfoo", "10000")
+	testSdkVersionFlag("libbar", "29")
+
+	ctx = android.GroupFixturePreparers(
+		prepareForCcTestWithoutVndk,
+		android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+			if variables.BuildFlags == nil {
+				variables.BuildFlags = make(map[string]string)
+			}
+			variables.BuildFlags["RELEASE_BOARD_API_LEVEL_FROZEN"] = "true"
+		}),
+	).RunTestWithBp(t, bp)
+	testSdkVersionFlag("libfoo", "30")
+	testSdkVersionFlag("libbar", "29")
+}

cc/object_test.go

@@ -22,7 +22,7 @@ import (
 )
 
 func TestMinSdkVersionsOfCrtObjects(t *testing.T) {
-	ctx := testCc(t, `
+	bp := `
 		cc_object {
 			name: "crt_foo",
 			srcs: ["foo.c"],
@@ -30,8 +30,8 @@ func TestMinSdkVersionsOfCrtObjects(t *testing.T) {
 			stl: "none",
 			min_sdk_version: "28",
 			vendor_available: true,
-		}`)
-
+		}
+	`
 	variants := []struct {
 		variant string
 		num     string
@@ -43,11 +43,17 @@ func TestMinSdkVersionsOfCrtObjects(t *testing.T) {
 		{"android_arm64_armv8-a_sdk_current", "10000"},
 		{"android_vendor.29_arm64_armv8-a", "29"},
 	}
+
+	ctx := prepareForCcTest.RunTestWithBp(t, bp)
 	for _, v := range variants {
 		cflags := ctx.ModuleForTests("crt_foo", v.variant).Rule("cc").Args["cFlags"]
 		expected := "-target aarch64-linux-android" + v.num + " "
 		android.AssertStringDoesContain(t, "cflag", cflags, expected)
 	}
+	ctx = prepareForCcTestWithoutVndk.RunTestWithBp(t, bp)
+	android.AssertStringDoesContain(t, "cflag",
+		ctx.ModuleForTests("crt_foo", "android_vendor_arm64_armv8-a").Rule("cc").Args["cFlags"],
+		"-target aarch64-linux-android10000 ")
 }
 
 func TestUseCrtObjectOfCorrectVersion(t *testing.T) {