Add LLNDK stubs and headers to VNDK snapshot

LLNDK stubs and headers are required to build the vendor modules
against VNDK snapshot libraries. Add the LLNDK stubs and headers to
the VNDK snapshot prebuilt files.
The stub libraries will be included in shared/llndk-stub directory.

Bug: 181815415
Test: development/vndk/snapshot/build.sh --build-artifacts
Change-Id: If518f3e91080e69fa1da94af0aa27320d4e71a08

cc/cc_test.go

@@ -546,6 +546,22 @@ func TestVndk(t *testing.T) {
 			},
 		}
 
+		cc_library {
+			name: "libllndk",
+			llndk_stubs: "libllndk.llndk",
+		}
+
+		llndk_library {
+			name: "libllndk.llndk",
+			symbol_file: "",
+			export_llndk_headers: ["libllndk_headers"],
+		}
+
+		llndk_headers {
+			name: "libllndk_headers",
+			export_include_dirs: ["include"],
+		}
+
 		llndk_libraries_txt {
 			name: "llndk.libraries.txt",
 		}
@@ -597,8 +613,11 @@ func TestVndk(t *testing.T) {
 
 	vndkCoreLibPath := filepath.Join(vndkLibPath, "shared", "vndk-core")
 	vndkSpLibPath := filepath.Join(vndkLibPath, "shared", "vndk-sp")
+	llndkLibPath := filepath.Join(vndkLibPath, "shared", "llndk-stub")
+
 	vndkCoreLib2ndPath := filepath.Join(vndkLib2ndPath, "shared", "vndk-core")
 	vndkSpLib2ndPath := filepath.Join(vndkLib2ndPath, "shared", "vndk-sp")
+	llndkLib2ndPath := filepath.Join(vndkLib2ndPath, "shared", "llndk-stub")
 
 	variant := "android_vendor.29_arm64_armv8-a_shared"
 	variant2nd := "android_vendor.29_arm_armv7-a-neon_shared"
@@ -611,6 +630,8 @@ func TestVndk(t *testing.T) {
 	checkSnapshot(t, ctx, snapshotSingleton, "libvndk_product", "libvndk_product.so", vndkCoreLib2ndPath, variant2nd)
 	checkSnapshot(t, ctx, snapshotSingleton, "libvndk_sp", "libvndk_sp-x.so", vndkSpLibPath, variant)
 	checkSnapshot(t, ctx, snapshotSingleton, "libvndk_sp", "libvndk_sp-x.so", vndkSpLib2ndPath, variant2nd)
+	checkSnapshot(t, ctx, snapshotSingleton, "libllndk", "libllndk.so", llndkLibPath, variant)
+	checkSnapshot(t, ctx, snapshotSingleton, "libllndk", "libllndk.so", llndkLib2ndPath, variant2nd)
 
 	snapshotConfigsPath := filepath.Join(snapshotVariantPath, "configs")
 	checkSnapshot(t, ctx, snapshotSingleton, "llndk.libraries.txt", "llndk.libraries.txt", snapshotConfigsPath, "")
@@ -623,6 +644,7 @@ func TestVndk(t *testing.T) {
 		"LLNDK: libc.so",
 		"LLNDK: libdl.so",
 		"LLNDK: libft2.so",
+		"LLNDK: libllndk.so",
 		"LLNDK: libm.so",
 		"VNDK-SP: libc++.so",
 		"VNDK-SP: libvndk_sp-x.so",
@@ -639,7 +661,7 @@ func TestVndk(t *testing.T) {
 		"VNDK-product: libvndk_product.so",
 		"VNDK-product: libvndk_sp_product_private-x.so",
 	})
-	checkVndkLibrariesOutput(t, ctx, "llndk.libraries.txt", []string{"libc.so", "libdl.so", "libft2.so", "libm.so"})
+	checkVndkLibrariesOutput(t, ctx, "llndk.libraries.txt", []string{"libc.so", "libdl.so", "libft2.so", "libllndk.so", "libm.so"})
 	checkVndkLibrariesOutput(t, ctx, "vndkcore.libraries.txt", []string{"libvndk-private.so", "libvndk.so", "libvndk_product.so"})
 	checkVndkLibrariesOutput(t, ctx, "vndksp.libraries.txt", []string{"libc++.so", "libvndk_sp-x.so", "libvndk_sp_private-x.so", "libvndk_sp_product_private-x.so"})
 	checkVndkLibrariesOutput(t, ctx, "vndkprivate.libraries.txt", []string{"libft2.so", "libvndk-private.so", "libvndk_sp_private-x.so", "libvndk_sp_product_private-x.so"})

cc/vndk.go

@@ -609,19 +609,26 @@ func isVndkSnapshotAware(config android.DeviceConfig, m *Module,
 	}
 	// !inVendor: There's product/vendor variants for VNDK libs. We only care about vendor variants.
 	// !installable: Snapshot only cares about "installable" modules.
+	// !m.IsLlndk: llndk stubs are required for building against snapshots.
 	// IsSnapshotPrebuilt: Snapshotting a snapshot doesn't make sense.
-	if !m.InVendor() || !m.installable(apexInfo) || m.IsSnapshotPrebuilt() {
+	// !outputFile.Valid: Snapshot requires valid output file.
+	if !m.InVendor() || (!m.installable(apexInfo) && !m.IsLlndk()) || m.IsSnapshotPrebuilt() || !m.outputFile.Valid() {
 		return nil, "", false
 	}
 	l, ok := m.linker.(snapshotLibraryInterface)
 	if !ok || !l.shared() {
 		return nil, "", false
 	}
-	if m.VndkVersion() == config.PlatformVndkVersion() && m.IsVndk() && !m.IsVndkExt() {
+	if m.VndkVersion() == config.PlatformVndkVersion() {
-		if m.isVndkSp() {
+		if m.IsVndk() && !m.IsVndkExt() {
-			return l, "vndk-sp", true
+			if m.isVndkSp() {
-		} else {
+				return l, "vndk-sp", true
-			return l, "vndk-core", true
+			} else {
+				return l, "vndk-core", true
+			}
+		} else if l.hasLLNDKStubs() && l.stubsVersion() == "" {
+			// Use default version for the snapshot.
+			return l, "llndk-stub", true
 		}
 	}
 
@@ -652,12 +659,16 @@ func (c *vndkSnapshotSingleton) GenerateBuildActions(ctx android.SingletonContex
 						(VNDK-core libraries, e.g. libbinder.so)
 					vndk-sp/
 						(VNDK-SP libraries, e.g. libc++.so)
+					llndk-stub/
+						(LLNDK stub libraries)
 			arch-{TARGET_2ND_ARCH}-{TARGET_2ND_ARCH_VARIANT}/
 				shared/
 					vndk-core/
 						(VNDK-core libraries, e.g. libbinder.so)
 					vndk-sp/
 						(VNDK-SP libraries, e.g. libc++.so)
+					llndk-stub/
+						(LLNDK stub libraries)
 			binder32/
 				(This directory is newly introduced in v28 (Android P) to hold
 				prebuilts built for 32-bit binder interface.)