Add LLNDK support for the VNDK

Instead of using the NDK headers and libraries, add LL-NDK specific
headers and library stubs for VNDK users. This allows us to provide an
expanded liblog interface.

Test: aosp_arm; m -j
Test: Enable BOARD_VNDK_VERSION on aosp_arm; m -j
Test: Inspect out/soong/build.ninja before/after (w/o vndk)
Change-Id: Ic85f07fa10c695b5baab10c41f5e0ad38700bf3d

Android.bp

@@ -147,6 +147,8 @@ bootstrap_go_package {
         "cc/ndk_headers.go",
         "cc/ndk_library.go",
         "cc/ndk_sysroot.go",
+
+        "cc/llndk_library.go",
     ],
     testSrcs: [
         "cc/cc_test.go",

cc/androidmk.go

@@ -298,3 +298,19 @@ func (c *stubDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkDa
 		return nil
 	})
 }
+
+func (c *llndkStubDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
+	ret.Class = "SHARED_LIBRARIES"
+
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+		c.libraryDecorator.androidMkWriteExportedFlags(w)
+
+		fmt.Fprintln(w, "LOCAL_BUILT_MODULE_STEM := $(LOCAL_MODULE)"+outputFile.Ext())
+		fmt.Fprintln(w, "LOCAL_STRIP_MODULE := false")
+		fmt.Fprintln(w, "LOCAL_SYSTEM_SHARED_LIBRARIES :=")
+		fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE := true")
+		fmt.Fprintln(w, "LOCAL_NO_NOTICE_FILE := true")
+
+		return nil
+	})
+}

cc/cc.go

@@ -638,7 +638,7 @@ func (c *Module) DepsMutator(actx android.BottomUpMutatorContext) {
 
 	variantNdkLibs := []string{}
 	variantLateNdkLibs := []string{}
-	if ctx.sdk() || ctx.vndk() {
+	if ctx.Os() == android.Android {
 		version := ctx.sdkVersion()
 
 		// Rewrites the names of shared libraries into the names of the NDK
@@ -655,12 +655,14 @@ func (c *Module) DepsMutator(actx android.BottomUpMutatorContext) {
 			variantLibs := []string{}
 			nonvariantLibs := []string{}
 			for _, entry := range list {
-				if inList(entry, ndkPrebuiltSharedLibraries) {
+				if ctx.sdk() && inList(entry, ndkPrebuiltSharedLibraries) {
 					if !inList(entry, ndkMigratedLibs) {
 						nonvariantLibs = append(nonvariantLibs, entry+".ndk."+version)
 					} else {
 						variantLibs = append(variantLibs, entry+ndkLibrarySuffix)
 					}
+				} else if ctx.vndk() && inList(entry, config.LLndkLibraries()) {
+					nonvariantLibs = append(nonvariantLibs, entry+llndkLibrarySuffix)
 				} else {
 					nonvariantLibs = append(nonvariantLibs, entry)
 				}

cc/compiler.go

@@ -205,7 +205,7 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flag
 		}
 	}
 
-	if ctx.sdk() || ctx.vndk() {
+	if ctx.sdk() {
 		// The NDK headers are installed to a common sysroot. While a more
 		// typical Soong approach would be to only make the headers for the
 		// library you're using available, we're trying to emulate the NDK
@@ -233,6 +233,11 @@ func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags) Flag
 		flags.SystemIncludeFlags = append(flags.SystemIncludeFlags, "-isystem "+legacyIncludes)
 	}
 
+	if ctx.vndk() {
+		flags.GlobalFlags = append(flags.GlobalFlags,
+			"-D__ANDROID_API__=__ANDROID_API_FUTURE__", "-D__ANDROID_VNDK__")
+	}
+
 	instructionSet := compiler.Properties.Instruction_set
 	if flags.RequiredInstructionSet != "" {
 		instructionSet = flags.RequiredInstructionSet
@@ -412,7 +417,7 @@ func (compiler *baseCompiler) hasSrcExt(ext string) bool {
 var gnuToCReplacer = strings.NewReplacer("gnu", "c")
 
 func ndkPathDeps(ctx ModuleContext) android.Paths {
-	if ctx.sdk() || ctx.vndk() {
+	if ctx.sdk() {
 		// The NDK sysroot timestamp file depends on all the NDK sysroot files
 		// (headers and libraries).
 		return android.Paths{getNdkSysrootTimestampFile(ctx)}

cc/config/global.go

@@ -178,6 +178,13 @@ func VndkLibraries() []string {
 	return []string{}
 }
 
+// This needs to be kept up to date with the list in system/core/rootdir/etc/ld.config.txt:
+// [vendor]
+// namespace.default.link.system.shared_libs
+func LLndkLibraries() []string {
+	return []string{"libc", "libm", "libdl", "liblog", "ld-android"}
+}
+
 func replaceFirst(slice []string, from, to string) {
 	if slice[0] != from {
 		panic(fmt.Errorf("Expected %q, found %q", from, to))

cc/llndk_library.go

@@ -0,0 +1,169 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cc
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/google/blueprint"
+
+	"android/soong/android"
+)
+
+var (
+	llndkLibrarySuffix = ".llndk"
+)
+
+// Creates a stub shared library based on the provided version file.
+//
+// The name of the generated file will be based on the module name by stripping
+// the ".llndk" suffix from the module name. Module names must end with ".llndk"
+// (as a convention to allow soong to guess the LL-NDK name of a dependency when
+// needed). "libfoo.llndk" will generate "libfoo.so".
+//
+// Example:
+//
+// llndk_library {
+//     name: "libfoo.llndk",
+//     symbol_file: "libfoo.map.txt",
+//     export_include_dirs: ["include_vndk"],
+// }
+//
+type llndkLibraryProperties struct {
+	// Relative path to the symbol map.
+	// An example file can be seen here: TODO(danalbert): Make an example.
+	Symbol_file string
+
+	// Whether to export any headers as -isystem instead of -I. Mainly for use by
+	// bionic/libc.
+	Export_headers_as_system bool
+
+	// Which headers to process with versioner. This really only handles
+	// bionic/libc/include right now.
+	Export_preprocessed_headers []string
+
+	// Whether the system library uses symbol versions.
+	Unversioned bool
+}
+
+type llndkStubDecorator struct {
+	*libraryDecorator
+
+	Properties llndkLibraryProperties
+
+	exportHeadersTimestamp android.OptionalPath
+	versionScriptPath      android.ModuleGenPath
+}
+
+func (stub *llndkStubDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
+	if !strings.HasSuffix(ctx.ModuleName(), llndkLibrarySuffix) {
+		ctx.ModuleErrorf("llndk_library modules names must be suffixed with %q\n",
+			llndkLibrarySuffix)
+	}
+	objs, versionScript := compileStubLibrary(ctx, flags, stub.Properties.Symbol_file, "current", "--vndk")
+	stub.versionScriptPath = versionScript
+	return objs
+}
+
+func (stub *llndkStubDecorator) linkerDeps(ctx DepsContext, deps Deps) Deps {
+	return Deps{}
+}
+
+func (stub *llndkStubDecorator) linkerFlags(ctx ModuleContext, flags Flags) Flags {
+	stub.libraryDecorator.libName = strings.TrimSuffix(ctx.ModuleName(),
+		llndkLibrarySuffix)
+	return stub.libraryDecorator.linkerFlags(ctx, flags)
+}
+
+func (stub *llndkStubDecorator) processHeaders(ctx ModuleContext, srcHeaderDir string, outDir android.ModuleGenPath) android.Path {
+	srcDir := android.PathForModuleSrc(ctx, srcHeaderDir)
+	srcFiles := ctx.Glob(filepath.Join(srcDir.String(), "**/*.h"), nil)
+
+	var installPaths []android.WritablePath
+	for _, header := range srcFiles {
+		headerDir := filepath.Dir(header.String())
+		relHeaderDir, err := filepath.Rel(srcDir.String(), headerDir)
+		if err != nil {
+			ctx.ModuleErrorf("filepath.Rel(%q, %q) failed: %s",
+				srcDir.String(), headerDir, err)
+			continue
+		}
+
+		installPaths = append(installPaths, outDir.Join(ctx, relHeaderDir, header.Base()))
+	}
+
+	return processHeadersWithVersioner(ctx, srcDir, outDir, srcFiles, installPaths)
+}
+
+func (stub *llndkStubDecorator) link(ctx ModuleContext, flags Flags, deps PathDeps,
+	objs Objects) android.Path {
+
+	if !stub.Properties.Unversioned {
+		linkerScriptFlag := "-Wl,--version-script," + stub.versionScriptPath.String()
+		flags.LdFlags = append(flags.LdFlags, linkerScriptFlag)
+	}
+
+	if len(stub.Properties.Export_preprocessed_headers) > 0 {
+		genHeaderOutDir := android.PathForModuleGen(ctx, "include")
+
+		var timestampFiles android.Paths
+		for _, dir := range stub.Properties.Export_preprocessed_headers {
+			timestampFiles = append(timestampFiles, stub.processHeaders(ctx, dir, genHeaderOutDir))
+		}
+
+		includePrefix := "-I "
+		if stub.Properties.Export_headers_as_system {
+			includePrefix = "-isystem "
+		}
+
+		stub.reexportFlags([]string{includePrefix + " " + genHeaderOutDir.String()})
+		stub.reexportDeps(timestampFiles)
+	}
+
+	if stub.Properties.Export_headers_as_system {
+		stub.exportIncludes(ctx, "-isystem")
+		stub.libraryDecorator.flagExporter.Properties.Export_include_dirs = []string{}
+	}
+
+	return stub.libraryDecorator.link(ctx, flags, deps, objs)
+}
+
+func newLLndkStubLibrary() (*Module, []interface{}) {
+	module, library := NewLibrary(android.DeviceSupported)
+	library.BuildOnlyShared()
+	module.stl = nil
+	module.sanitize = nil
+	library.StripProperties.Strip.None = true
+
+	stub := &llndkStubDecorator{
+		libraryDecorator: library,
+	}
+	module.compiler = stub
+	module.linker = stub
+	module.installer = nil
+
+	return module, []interface{}{&stub.Properties, &library.MutatedProperties, &library.flagExporter.Properties}
+}
+
+func llndkLibraryFactory() (blueprint.Module, []interface{}) {
+	module, properties := newLLndkStubLibrary()
+	return android.InitAndroidArchModule(module, android.DeviceSupported,
+		android.MultilibBoth, properties...)
+}
+
+func init() {
+	android.RegisterModuleType("llndk_library", llndkLibraryFactory)
+}

cc/makevars.go

@@ -58,6 +58,7 @@ func makeVarsProvider(ctx android.MakeVarsContext) {
 		ctx.Strict("BOARD_VNDK_VERSION", "")
 	}
 	ctx.Strict("VNDK_LIBRARIES", strings.Join(config.VndkLibraries(), " "))
+	ctx.Strict("LLNDK_LIBRARIES", strings.Join(config.LLndkLibraries(), " "))
 
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_CFLAGS", asanCflags)
 	ctx.Strict("ADDRESS_SANITIZER_CONFIG_EXTRA_LDFLAGS", asanLdflags)

cc/ndk_headers.go

@@ -204,6 +204,10 @@ func (m *preprocessedHeaderModule) GenerateAndroidBuildActions(ctx android.Modul
 		ctx.ModuleErrorf("glob %q matched zero files", m.properties.From)
 	}
 
+	processHeadersWithVersioner(ctx, fromSrcPath, toOutputPath, srcFiles, installPaths)
+}
+
+func processHeadersWithVersioner(ctx android.ModuleContext, srcDir, outDir android.Path, srcFiles android.Paths, installPaths []android.WritablePath) android.Path {
 	// The versioner depends on a dependencies directory to simplify determining include paths
 	// when parsing headers. This directory contains architecture specific directories as well
 	// as a common directory, each of which contains symlinks to the actually directories to
@@ -239,10 +243,12 @@ func (m *preprocessedHeaderModule) GenerateAndroidBuildActions(ctx android.Modul
 		ImplicitOutputs: installPaths,
 		Args: map[string]string{
 			"depsPath": depsPath.String(),
-			"srcDir":   fromSrcPath.String(),
-			"outDir":   toOutputPath.String(),
+			"srcDir":   srcDir.String(),
+			"outDir":   outDir.String(),
 		},
 	})
+
+	return timestampFile
 }
 
 func preprocessedNdkHeadersFactory() (blueprint.Module, []interface{}) {

cc/ndk_library.go

@@ -30,10 +30,10 @@ var (
 
 	genStubSrc = pctx.AndroidStaticRule("genStubSrc",
 		blueprint.RuleParams{
-			Command:     "$toolPath --arch $arch --api $apiLevel $in $out",
+			Command:     "$toolPath --arch $arch --api $apiLevel $vndk $in $out",
 			Description: "genStubSrc $out",
 			CommandDeps: []string{"$toolPath"},
-		}, "arch", "apiLevel")
+		}, "arch", "apiLevel", "vndk")
 
 	ndkLibrarySuffix = ".ndk"
 
@@ -241,28 +241,20 @@ func (c *stubDecorator) compilerInit(ctx BaseModuleContext) {
 	ndkMigratedLibs = append(ndkMigratedLibs, name)
 }
 
-func (c *stubDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
+func compileStubLibrary(ctx ModuleContext, flags Flags, symbolFile, apiLevel, vndk string) (Objects, android.ModuleGenPath) {
 	arch := ctx.Arch().ArchType.String()
 
-	if !strings.HasSuffix(ctx.ModuleName(), ndkLibrarySuffix) {
-		ctx.ModuleErrorf("ndk_library modules names must be suffixed with %q\n",
-			ndkLibrarySuffix)
-	}
-	libName := strings.TrimSuffix(ctx.ModuleName(), ndkLibrarySuffix)
-	fileBase := fmt.Sprintf("%s.%s.%s", libName, arch, c.properties.ApiLevel)
-	stubSrcName := fileBase + ".c"
-	stubSrcPath := android.PathForModuleGen(ctx, stubSrcName)
-	versionScriptName := fileBase + ".map"
-	versionScriptPath := android.PathForModuleGen(ctx, versionScriptName)
-	c.versionScriptPath = versionScriptPath
-	symbolFilePath := android.PathForModuleSrc(ctx, c.properties.Symbol_file)
+	stubSrcPath := android.PathForModuleGen(ctx, "stub.c")
+	versionScriptPath := android.PathForModuleGen(ctx, "stub.map")
+	symbolFilePath := android.PathForModuleSrc(ctx, symbolFile)
 	ctx.ModuleBuild(pctx, android.ModuleBuildParams{
 		Rule:    genStubSrc,
 		Outputs: []android.WritablePath{stubSrcPath, versionScriptPath},
 		Input:   symbolFilePath,
 		Args: map[string]string{
 			"arch":     arch,
-			"apiLevel": c.properties.ApiLevel,
+			"apiLevel": apiLevel,
+			"vndk":     vndk,
 		},
 	})
 
@@ -280,7 +272,17 @@ func (c *stubDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) O
 
 	subdir := ""
 	srcs := []android.Path{stubSrcPath}
-	return compileObjs(ctx, flagsToBuilderFlags(flags), subdir, srcs, nil)
+	return compileObjs(ctx, flagsToBuilderFlags(flags), subdir, srcs, nil), versionScriptPath
+}
+
+func (c *stubDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
+	if !strings.HasSuffix(ctx.ModuleName(), ndkLibrarySuffix) {
+		ctx.ModuleErrorf("ndk_library modules names must be suffixed with %q\n",
+			ndkLibrarySuffix)
+	}
+	objs, versionScript := compileStubLibrary(ctx, flags, c.properties.Symbol_file, c.properties.ApiLevel, "")
+	c.versionScriptPath = versionScript
+	return objs
 }
 
 func (linker *stubDecorator) linkerDeps(ctx DepsContext, deps Deps) Deps {