cc/compiler.go - android_build_soong - Gitiles

 // Copyright 2016 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 (
 	"fmt"
 	"path/filepath"
 	"strings"

 	"github.com/google/blueprint/proptools"

 	"android/soong/android"
 	"android/soong/cc/config"
 )

 // This file contains the basic C/C++/assembly to .o compliation steps

 type BaseCompilerProperties struct {
 	// list of source files used to compile the C/C++ module.  May be .c, .cpp, or .S files.
 	// srcs may reference the outputs of other modules that produce source files like genrule
 	// or filegroup using the syntax ":module".
 	Srcs []string `android:"arch_variant"`

 	// list of source files that should not be used to build the C/C++ module.
 	// This is most useful in the arch/multilib variants to remove non-common files
 	Exclude_srcs []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for C and C++ compiles.
 	Cflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for C++ compiles
 	Cppflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for C compiles
 	Conlyflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for .S compiles
 	Asflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for C and C++ compiles when
 	// compiling with clang
 	Clang_cflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for .S compiles when
 	// compiling with clang
 	Clang_asflags []string `android:"arch_variant"`

 	// list of module-specific flags that will be used for .y and .yy compiles
 	Yaccflags []string

 	// the instruction set architecture to use to compile the C/C++
 	// module.
 	Instruction_set *string `android:"arch_variant"`

 	// list of directories relative to the root of the source tree that will
 	// be added to the include path using -I.
 	// If possible, don't use this.  If adding paths from the current directory use
 	// local_include_dirs, if adding paths from other modules use export_include_dirs in
 	// that module.
 	Include_dirs []string `android:"arch_variant,variant_prepend"`

 	// list of directories relative to the Blueprints file that will
 	// be added to the include path using -I
 	Local_include_dirs []string `android:"arch_variant,variant_prepend"`

 	// Add the directory containing the Android.bp file to the list of include
 	// directories. Defaults to true.
 	Include_build_directory *bool

 	// list of generated sources to compile. These are the names of gensrcs or
 	// genrule modules.
 	Generated_sources []string `android:"arch_variant"`

 	// list of generated headers to add to the include path. These are the names
 	// of genrule modules.
 	Generated_headers []string `android:"arch_variant"`

 	// pass -frtti instead of -fno-rtti
 	Rtti *bool

 	// C standard version to use. Can be a specific version (such as "gnu11"),
 	// "experimental" (which will use draft versions like C1x when available),
 	// or the empty string (which will use the default).
 	C_std *string

 	// C++ standard version to use. Can be a specific version (such as
 	// "gnu++11"), "experimental" (which will use draft versions like C++1z when
 	// available), or the empty string (which will use the default).
 	Cpp_std *string

 	// if set to false, use -std=c++* instead of -std=gnu++*
 	Gnu_extensions *bool

 	Aidl struct {
 		// list of directories that will be added to the aidl include paths.
 		Include_dirs []string

 		// list of directories relative to the Blueprints file that will
 		// be added to the aidl include paths.
 		Local_include_dirs []string

 		// whether to generate traces (for systrace) for this interface
 		Generate_traces *bool
 	}

 	Renderscript struct {
 		// list of directories that will be added to the llvm-rs-cc include paths
 		Include_dirs []string

 		// list of flags that will be passed to llvm-rs-cc
 		Flags []string

 		// Renderscript API level to target
 		Target_api *string
 	}

 	Debug, Release struct {
 		// list of module-specific flags that will be used for C and C++ compiles in debug or
 		// release builds
 		Cflags []string `android:"arch_variant"`
 	} `android:"arch_variant"`

 	Target struct {
 		Vendor struct {
 			// list of source files that should only be used in the
 			// vendor variant of the C/C++ module.
 			Srcs []string

 			// list of source files that should not be used to
 			// build the vendor variant of the C/C++ module.
 			Exclude_srcs []string

 			// List of additional cflags that should be used to build the vendor
 			// variant of the C/C++ module.
 			Cflags []string
 		}
 		Recovery struct {
 			// list of source files that should only be used in the
 			// recovery variant of the C/C++ module.
 			Srcs []string

 			// list of source files that should not be used to
 			// build the recovery variant of the C/C++ module.
 			Exclude_srcs []string

 			// List of additional cflags that should be used to build the recovery
 			// variant of the C/C++ module.
 			Cflags []string
 		}
 	}

 	Proto struct {
 		// Link statically against the protobuf runtime
 		Static *bool `android:"arch_variant"`
 	} `android:"arch_variant"`

 	// Stores the original list of source files before being cleared by library reuse
 	OriginalSrcs []string `blueprint:"mutated"`

 	// Build and link with OpenMP
 	Openmp *bool `android:"arch_variant"`
 }

 func NewBaseCompiler() *baseCompiler {
 	return &baseCompiler{}
 }

 type baseCompiler struct {
 	Properties BaseCompilerProperties
 	Proto      android.ProtoProperties
 	cFlagsDeps android.Paths
 	pathDeps   android.Paths
 	flags      builderFlags

 	// Sources that were passed to the C/C++ compiler
 	srcs android.Paths

 	// Sources that were passed in the Android.bp file, including generated sources generated by
 	// other modules and filegroups. May include source files that have not yet been translated to
 	// C/C++ (.aidl, .proto, etc.)
 	srcsBeforeGen android.Paths
 }

 var _ compiler = (*baseCompiler)(nil)

 type CompiledInterface interface {
 	Srcs() android.Paths
 }

 func (compiler *baseCompiler) Srcs() android.Paths {
 	return append(android.Paths{}, compiler.srcs...)
 }

 func (compiler *baseCompiler) appendCflags(flags []string) {
 	compiler.Properties.Cflags = append(compiler.Properties.Cflags, flags...)
 }

 func (compiler *baseCompiler) appendAsflags(flags []string) {
 	compiler.Properties.Asflags = append(compiler.Properties.Asflags, flags...)
 }

 func (compiler *baseCompiler) compilerProps() []interface{} {
 	return []interface{}{&compiler.Properties, &compiler.Proto}
 }

 func (compiler *baseCompiler) compilerInit(ctx BaseModuleContext) {}

 func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
 	deps.GeneratedSources = append(deps.GeneratedSources, compiler.Properties.Generated_sources...)
 	deps.GeneratedHeaders = append(deps.GeneratedHeaders, compiler.Properties.Generated_headers...)

 	android.ExtractSourcesDeps(ctx, compiler.Properties.Srcs)
 	android.ExtractSourcesDeps(ctx, compiler.Properties.Exclude_srcs)

 	if compiler.hasSrcExt(".proto") {
 		deps = protoDeps(ctx, deps, &compiler.Proto, Bool(compiler.Properties.Proto.Static))
 	}

 	if compiler.hasSrcExt(".sysprop") {
 		deps.SharedLibs = append(deps.SharedLibs, "libbase")
 	}

 	if Bool(compiler.Properties.Openmp) {
 		deps.StaticLibs = append(deps.StaticLibs, "libomp")
 	}

 	return deps
 }

 // Return true if the module is in the WarningAllowedProjects.
 func warningsAreAllowed(subdir string) bool {
 	subdir += "/"
 	for _, prefix := range config.WarningAllowedProjects {
 		if strings.HasPrefix(subdir, prefix) {
 			return true
 		}
 	}
 	return false
 }

 func addToModuleList(ctx ModuleContext, key android.OnceKey, module string) {
 	getNamedMapForConfig(ctx.Config(), key).Store(module, true)
 }

 // Create a Flags struct that collects the compile flags from global values,
 // per-target values, module type values, and per-module Blueprints properties
 func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps PathDeps) Flags {
 	tc := ctx.toolchain()

 	compiler.srcsBeforeGen = ctx.ExpandSources(compiler.Properties.Srcs, compiler.Properties.Exclude_srcs)
 	compiler.srcsBeforeGen = append(compiler.srcsBeforeGen, deps.GeneratedSources...)

 	CheckBadCompilerFlags(ctx, "cflags", compiler.Properties.Cflags)
 	CheckBadCompilerFlags(ctx, "cppflags", compiler.Properties.Cppflags)
 	CheckBadCompilerFlags(ctx, "conlyflags", compiler.Properties.Conlyflags)
 	CheckBadCompilerFlags(ctx, "asflags", compiler.Properties.Asflags)
 	CheckBadCompilerFlags(ctx, "vendor.cflags", compiler.Properties.Target.Vendor.Cflags)
 	CheckBadCompilerFlags(ctx, "recovery.cflags", compiler.Properties.Target.Recovery.Cflags)

 	esc := proptools.NinjaAndShellEscape

 	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Cflags)...)
 	flags.CppFlags = append(flags.CppFlags, esc(compiler.Properties.Cppflags)...)
 	flags.ConlyFlags = append(flags.ConlyFlags, esc(compiler.Properties.Conlyflags)...)
 	flags.AsFlags = append(flags.AsFlags, esc(compiler.Properties.Asflags)...)
 	flags.YasmFlags = append(flags.YasmFlags, esc(compiler.Properties.Asflags)...)
 	flags.YaccFlags = append(flags.YaccFlags, esc(compiler.Properties.Yaccflags)...)

 	// Include dir cflags
 	localIncludeDirs := android.PathsForModuleSrc(ctx, compiler.Properties.Local_include_dirs)
 	if len(localIncludeDirs) > 0 {
 		f := includeDirsToFlags(localIncludeDirs)
 		flags.GlobalFlags = append(flags.GlobalFlags, f)
 		flags.YasmFlags = append(flags.YasmFlags, f)
 	}
 	rootIncludeDirs := android.PathsForSource(ctx, compiler.Properties.Include_dirs)
 	if len(rootIncludeDirs) > 0 {
 		f := includeDirsToFlags(rootIncludeDirs)
 		flags.GlobalFlags = append(flags.GlobalFlags, f)
 		flags.YasmFlags = append(flags.YasmFlags, f)
 	}

 	if compiler.Properties.Include_build_directory == nil ||
 		*compiler.Properties.Include_build_directory {
 		flags.GlobalFlags = append(flags.GlobalFlags, "-I"+android.PathForModuleSrc(ctx).String())
 		flags.YasmFlags = append(flags.YasmFlags, "-I"+android.PathForModuleSrc(ctx).String())
 	}

 	if !(ctx.useSdk() || ctx.useVndk()) || ctx.Host() {
 		flags.SystemIncludeFlags = append(flags.SystemIncludeFlags,
 			"${config.CommonGlobalIncludes}",
 			tc.IncludeFlags(),
 			"${config.CommonNativehelperInclude}")
 	}

 	if ctx.useSdk() {
 		// TODO: Switch to --sysroot.
 		// 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
 		// behavior here, and the NDK always has all the NDK headers available.
 		flags.SystemIncludeFlags = append(flags.SystemIncludeFlags,
 			"-isystem "+getCurrentIncludePath(ctx).String(),
 			"-isystem "+getCurrentIncludePath(ctx).Join(ctx, config.NDKTriple(tc)).String())

 		// TODO: Migrate to API suffixed triple?
 		// Traditionally this has come from android/api-level.h, but with the
 		// libc headers unified it must be set by the build system since we
 		// don't have per-API level copies of that header now.
 		version := ctx.sdkVersion()
 		if version == "current" {
 			version = "__ANDROID_API_FUTURE__"
 		}
 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-D__ANDROID_API__="+version)
 	}

 	if ctx.useVndk() {
 		// sdkVersion() returns VNDK version for vendor modules.
 		version := ctx.sdkVersion()
 		if version == "current" {
 			version = "__ANDROID_API_FUTURE__"
 		}
 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-D__ANDROID_API__="+version, "-D__ANDROID_VNDK__")
 	}

 	if ctx.inRecovery() {
 		flags.GlobalFlags = append(flags.GlobalFlags, "-D__ANDROID_RECOVERY__")
 	}

 	if ctx.apexName() != "" {
 		flags.GlobalFlags = append(flags.GlobalFlags, "-D__ANDROID_APEX__="+ctx.apexName())
 	}

 	instructionSet := String(compiler.Properties.Instruction_set)
 	if flags.RequiredInstructionSet != "" {
 		instructionSet = flags.RequiredInstructionSet
 	}
 	instructionSetFlags, err := tc.ClangInstructionSetFlags(instructionSet)
 	if err != nil {
 		ctx.ModuleErrorf("%s", err)
 	}

 	CheckBadCompilerFlags(ctx, "release.cflags", compiler.Properties.Release.Cflags)

 	// TODO: debug
 	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Release.Cflags)...)

 	CheckBadCompilerFlags(ctx, "clang_cflags", compiler.Properties.Clang_cflags)
 	CheckBadCompilerFlags(ctx, "clang_asflags", compiler.Properties.Clang_asflags)

 	flags.CFlags = config.ClangFilterUnknownCflags(flags.CFlags)
 	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Clang_cflags)...)
 	flags.AsFlags = append(flags.AsFlags, esc(compiler.Properties.Clang_asflags)...)
 	flags.CppFlags = config.ClangFilterUnknownCflags(flags.CppFlags)
 	flags.ConlyFlags = config.ClangFilterUnknownCflags(flags.ConlyFlags)
 	flags.LdFlags = config.ClangFilterUnknownCflags(flags.LdFlags)

 	target := "-target " + tc.ClangTriple()
 	gccPrefix := "-B" + config.ToolPath(tc)

 	flags.CFlags = append(flags.CFlags, target, gccPrefix)
 	flags.AsFlags = append(flags.AsFlags, target, gccPrefix)
 	flags.LdFlags = append(flags.LdFlags, target, gccPrefix)

 	hod := "Host"
 	if ctx.Os().Class == android.Device {
 		hod = "Device"
 	}

 	flags.GlobalFlags = append(flags.GlobalFlags, instructionSetFlags)
 	flags.ConlyFlags = append([]string{"${config.CommonGlobalConlyflags}"}, flags.ConlyFlags...)
 	flags.CppFlags = append([]string{fmt.Sprintf("${config.%sGlobalCppflags}", hod)}, flags.CppFlags...)

 	flags.AsFlags = append(flags.AsFlags, tc.ClangAsflags())
 	flags.CppFlags = append([]string{"${config.CommonClangGlobalCppflags}"}, flags.CppFlags...)
 	flags.GlobalFlags = append(flags.GlobalFlags,
 		tc.ClangCflags(),
 		"${config.CommonClangGlobalCflags}",
 		fmt.Sprintf("${config.%sClangGlobalCflags}", hod))

 	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
 		flags.GlobalFlags = append([]string{"${config.ClangExternalCflags}"}, flags.GlobalFlags...)
 	}

 	if tc.Bionic() {
 		if Bool(compiler.Properties.Rtti) {
 			flags.CppFlags = append(flags.CppFlags, "-frtti")
 		} else {
 			flags.CppFlags = append(flags.CppFlags, "-fno-rtti")
 		}
 	}

 	flags.AsFlags = append(flags.AsFlags, "-D__ASSEMBLY__")

 	flags.CppFlags = append(flags.CppFlags, tc.ClangCppflags())

 	flags.YasmFlags = append(flags.YasmFlags, tc.YasmFlags())

 	flags.GlobalFlags = append(flags.GlobalFlags, tc.ToolchainClangCflags())

 	cStd := config.CStdVersion
 	if String(compiler.Properties.C_std) == "experimental" {
 		cStd = config.ExperimentalCStdVersion
 	} else if String(compiler.Properties.C_std) != "" {
 		cStd = String(compiler.Properties.C_std)
 	}

 	cppStd := String(compiler.Properties.Cpp_std)
 	switch String(compiler.Properties.Cpp_std) {
 	case "":
 		cppStd = config.CppStdVersion
 	case "experimental":
 		cppStd = config.ExperimentalCppStdVersion
 	}

 	if compiler.Properties.Gnu_extensions != nil && *compiler.Properties.Gnu_extensions == false {
 		cStd = gnuToCReplacer.Replace(cStd)
 		cppStd = gnuToCReplacer.Replace(cppStd)
 	}

 	flags.ConlyFlags = append([]string{"-std=" + cStd}, flags.ConlyFlags...)
 	flags.CppFlags = append([]string{"-std=" + cppStd}, flags.CppFlags...)

 	if ctx.useVndk() {
 		flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Target.Vendor.Cflags)...)
 	}

 	if ctx.inRecovery() {
 		flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Target.Recovery.Cflags)...)
 	}

 	// We can enforce some rules more strictly in the code we own. strict
 	// indicates if this is code that we can be stricter with. If we have
 	// rules that we want to apply to *our* code (but maybe can't for
 	// vendor/device specific things), we could extend this to be a ternary
 	// value.
 	strict := true
 	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
 		strict = false
 	}

 	// Can be used to make some annotations stricter for code we can fix
 	// (such as when we mark functions as deprecated).
 	if strict {
 		flags.CFlags = append(flags.CFlags, "-DANDROID_STRICT")
 	}

 	if compiler.hasSrcExt(".proto") {
 		flags = protoFlags(ctx, flags, &compiler.Proto)
 	}

 	if compiler.hasSrcExt(".y") || compiler.hasSrcExt(".yy") {
 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-I"+android.PathForModuleGen(ctx, "yacc", ctx.ModuleDir()).String())
 	}

 	if compiler.hasSrcExt(".mc") {
 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-I"+android.PathForModuleGen(ctx, "windmc", ctx.ModuleDir()).String())
 	}

 	if compiler.hasSrcExt(".aidl") {
 		if len(compiler.Properties.Aidl.Local_include_dirs) > 0 {
 			localAidlIncludeDirs := android.PathsForModuleSrc(ctx, compiler.Properties.Aidl.Local_include_dirs)
 			flags.aidlFlags = append(flags.aidlFlags, includeDirsToFlags(localAidlIncludeDirs))
 		}
 		if len(compiler.Properties.Aidl.Include_dirs) > 0 {
 			rootAidlIncludeDirs := android.PathsForSource(ctx, compiler.Properties.Aidl.Include_dirs)
 			flags.aidlFlags = append(flags.aidlFlags, includeDirsToFlags(rootAidlIncludeDirs))
 		}

 		if Bool(compiler.Properties.Aidl.Generate_traces) {
 			flags.aidlFlags = append(flags.aidlFlags, "-t")
 		}

 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-I"+android.PathForModuleGen(ctx, "aidl").String())
 	}

 	if compiler.hasSrcExt(".rs") || compiler.hasSrcExt(".fs") {
 		flags = rsFlags(ctx, flags, &compiler.Properties)
 	}

 	if compiler.hasSrcExt(".sysprop") {
 		flags.GlobalFlags = append(flags.GlobalFlags,
 			"-I"+android.PathForModuleGen(ctx, "sysprop", "include").String())
 	}

 	if len(compiler.Properties.Srcs) > 0 {
 		module := ctx.ModuleDir() + "/Android.bp:" + ctx.ModuleName()
 		if inList("-Wno-error", flags.CFlags) || inList("-Wno-error", flags.CppFlags) {
 			addToModuleList(ctx, modulesUsingWnoErrorKey, module)
 		} else if !inList("-Werror", flags.CFlags) && !inList("-Werror", flags.CppFlags) {
 			if warningsAreAllowed(ctx.ModuleDir()) {
 				addToModuleList(ctx, modulesAddedWallKey, module)
 				flags.CFlags = append([]string{"-Wall"}, flags.CFlags...)
 			} else {
 				flags.CFlags = append([]string{"-Wall", "-Werror"}, flags.CFlags...)
 			}
 		}
 	}

 	if Bool(compiler.Properties.Openmp) {
 		flags.CFlags = append(flags.CFlags, "-fopenmp")
 	}

 	return flags
 }

 func (compiler *baseCompiler) hasSrcExt(ext string) bool {
 	for _, src := range compiler.srcsBeforeGen {
 		if src.Ext() == ext {
 			return true
 		}
 	}
 	for _, src := range compiler.Properties.Srcs {
 		if filepath.Ext(src) == ext {
 			return true
 		}
 	}
 	for _, src := range compiler.Properties.OriginalSrcs {
 		if filepath.Ext(src) == ext {
 			return true
 		}
 	}

 	return false
 }

 var gnuToCReplacer = strings.NewReplacer("gnu", "c")

 func ndkPathDeps(ctx ModuleContext) android.Paths {
 	if ctx.useSdk() {
 		// The NDK sysroot timestamp file depends on all the NDK sysroot files
 		// (headers and libraries).
 		return android.Paths{getNdkBaseTimestampFile(ctx)}
 	}
 	return nil
 }

 func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
 	pathDeps := deps.GeneratedHeaders
 	pathDeps = append(pathDeps, ndkPathDeps(ctx)...)

 	buildFlags := flagsToBuilderFlags(flags)

 	srcs := append(android.Paths(nil), compiler.srcsBeforeGen...)

 	srcs, genDeps := genSources(ctx, srcs, buildFlags)
 	pathDeps = append(pathDeps, genDeps...)

 	compiler.pathDeps = pathDeps
 	compiler.cFlagsDeps = flags.CFlagsDeps

 	// Save src, buildFlags and context
 	compiler.srcs = srcs

 	// Compile files listed in c.Properties.Srcs into objects
 	objs := compileObjs(ctx, buildFlags, "", srcs, pathDeps, compiler.cFlagsDeps)

 	if ctx.Failed() {
 		return Objects{}
 	}

 	return objs
 }

 // Compile a list of source files into objects a specified subdirectory
 func compileObjs(ctx android.ModuleContext, flags builderFlags,
 	subdir string, srcFiles, pathDeps android.Paths, cFlagsDeps android.Paths) Objects {

 	return TransformSourceToObj(ctx, subdir, srcFiles, flags, pathDeps, cFlagsDeps)
 }
	// Copyright 2016 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 (
	"fmt"
	"path/filepath"
	"strings"

	"github.com/google/blueprint/proptools"

	"android/soong/android"
	"android/soong/cc/config"
	)

	// This file contains the basic C/C++/assembly to .o compliation steps

	type BaseCompilerProperties struct {
	// list of source files used to compile the C/C++ module. May be .c, .cpp, or .S files.
	// srcs may reference the outputs of other modules that produce source files like genrule
	// or filegroup using the syntax ":module".
	Srcs []string `android:"arch_variant"`

	// list of source files that should not be used to build the C/C++ module.
	// This is most useful in the arch/multilib variants to remove non-common files
	Exclude_srcs []string `android:"arch_variant"`

	// list of module-specific flags that will be used for C and C++ compiles.
	Cflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for C++ compiles
	Cppflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for C compiles
	Conlyflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for .S compiles
	Asflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for C and C++ compiles when
	// compiling with clang
	Clang_cflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for .S compiles when
	// compiling with clang
	Clang_asflags []string `android:"arch_variant"`

	// list of module-specific flags that will be used for .y and .yy compiles
	Yaccflags []string

	// the instruction set architecture to use to compile the C/C++
	// module.
	Instruction_set *string `android:"arch_variant"`

	// list of directories relative to the root of the source tree that will
	// be added to the include path using -I.
	// If possible, don't use this. If adding paths from the current directory use
	// local_include_dirs, if adding paths from other modules use export_include_dirs in
	// that module.
	Include_dirs []string `android:"arch_variant,variant_prepend"`

	// list of directories relative to the Blueprints file that will
	// be added to the include path using -I
	Local_include_dirs []string `android:"arch_variant,variant_prepend"`

	// Add the directory containing the Android.bp file to the list of include
	// directories. Defaults to true.
	Include_build_directory *bool

	// list of generated sources to compile. These are the names of gensrcs or
	// genrule modules.
	Generated_sources []string `android:"arch_variant"`

	// list of generated headers to add to the include path. These are the names
	// of genrule modules.
	Generated_headers []string `android:"arch_variant"`

	// pass -frtti instead of -fno-rtti
	Rtti *bool

	// C standard version to use. Can be a specific version (such as "gnu11"),
	// "experimental" (which will use draft versions like C1x when available),
	// or the empty string (which will use the default).
	C_std *string

	// C++ standard version to use. Can be a specific version (such as
	// "gnu++11"), "experimental" (which will use draft versions like C++1z when
	// available), or the empty string (which will use the default).
	Cpp_std *string

	// if set to false, use -std=c++* instead of -std=gnu++*
	Gnu_extensions *bool

	Aidl struct {
	// list of directories that will be added to the aidl include paths.
	Include_dirs []string

	// list of directories relative to the Blueprints file that will
	// be added to the aidl include paths.
	Local_include_dirs []string

	// whether to generate traces (for systrace) for this interface
	Generate_traces *bool
	}

	Renderscript struct {
	// list of directories that will be added to the llvm-rs-cc include paths
	Include_dirs []string

	// list of flags that will be passed to llvm-rs-cc
	Flags []string

	// Renderscript API level to target
	Target_api *string
	}

	Debug, Release struct {
	// list of module-specific flags that will be used for C and C++ compiles in debug or
	// release builds
	Cflags []string `android:"arch_variant"`
	} `android:"arch_variant"`

	Target struct {
	Vendor struct {
	// list of source files that should only be used in the
	// vendor variant of the C/C++ module.
	Srcs []string

	// list of source files that should not be used to
	// build the vendor variant of the C/C++ module.
	Exclude_srcs []string

	// List of additional cflags that should be used to build the vendor
	// variant of the C/C++ module.
	Cflags []string
	}
	Recovery struct {
	// list of source files that should only be used in the
	// recovery variant of the C/C++ module.
	Srcs []string

	// list of source files that should not be used to
	// build the recovery variant of the C/C++ module.
	Exclude_srcs []string

	// List of additional cflags that should be used to build the recovery
	// variant of the C/C++ module.
	Cflags []string
	}
	}

	Proto struct {
	// Link statically against the protobuf runtime
	Static *bool `android:"arch_variant"`
	} `android:"arch_variant"`

	// Stores the original list of source files before being cleared by library reuse
	OriginalSrcs []string `blueprint:"mutated"`

	// Build and link with OpenMP
	Openmp *bool `android:"arch_variant"`
	}

	func NewBaseCompiler() *baseCompiler {
	return &baseCompiler{}
	}

	type baseCompiler struct {
	Properties BaseCompilerProperties
	Proto android.ProtoProperties
	cFlagsDeps android.Paths
	pathDeps android.Paths
	flags builderFlags

	// Sources that were passed to the C/C++ compiler
	srcs android.Paths

	// Sources that were passed in the Android.bp file, including generated sources generated by
	// other modules and filegroups. May include source files that have not yet been translated to
	// C/C++ (.aidl, .proto, etc.)
	srcsBeforeGen android.Paths
	}

	var _ compiler = (*baseCompiler)(nil)

	type CompiledInterface interface {
	Srcs() android.Paths
	}

	func (compiler *baseCompiler) Srcs() android.Paths {
	return append(android.Paths{}, compiler.srcs...)
	}

	func (compiler *baseCompiler) appendCflags(flags []string) {
	compiler.Properties.Cflags = append(compiler.Properties.Cflags, flags...)
	}

	func (compiler *baseCompiler) appendAsflags(flags []string) {
	compiler.Properties.Asflags = append(compiler.Properties.Asflags, flags...)
	}

	func (compiler *baseCompiler) compilerProps() []interface{} {
	return []interface{}{&compiler.Properties, &compiler.Proto}
	}

	func (compiler *baseCompiler) compilerInit(ctx BaseModuleContext) {}

	func (compiler *baseCompiler) compilerDeps(ctx DepsContext, deps Deps) Deps {
	deps.GeneratedSources = append(deps.GeneratedSources, compiler.Properties.Generated_sources...)
	deps.GeneratedHeaders = append(deps.GeneratedHeaders, compiler.Properties.Generated_headers...)

	android.ExtractSourcesDeps(ctx, compiler.Properties.Srcs)
	android.ExtractSourcesDeps(ctx, compiler.Properties.Exclude_srcs)

	if compiler.hasSrcExt(".proto") {
	deps = protoDeps(ctx, deps, &compiler.Proto, Bool(compiler.Properties.Proto.Static))
	}

	if compiler.hasSrcExt(".sysprop") {
	deps.SharedLibs = append(deps.SharedLibs, "libbase")
	}

	if Bool(compiler.Properties.Openmp) {
	deps.StaticLibs = append(deps.StaticLibs, "libomp")
	}

	return deps
	}

	// Return true if the module is in the WarningAllowedProjects.
	func warningsAreAllowed(subdir string) bool {
	subdir += "/"
	for _, prefix := range config.WarningAllowedProjects {
	if strings.HasPrefix(subdir, prefix) {
	return true
	}
	}
	return false
	}

	func addToModuleList(ctx ModuleContext, key android.OnceKey, module string) {
	getNamedMapForConfig(ctx.Config(), key).Store(module, true)
	}

	// Create a Flags struct that collects the compile flags from global values,
	// per-target values, module type values, and per-module Blueprints properties
	func (compiler *baseCompiler) compilerFlags(ctx ModuleContext, flags Flags, deps PathDeps) Flags {
	tc := ctx.toolchain()

	compiler.srcsBeforeGen = ctx.ExpandSources(compiler.Properties.Srcs, compiler.Properties.Exclude_srcs)
	compiler.srcsBeforeGen = append(compiler.srcsBeforeGen, deps.GeneratedSources...)

	CheckBadCompilerFlags(ctx, "cflags", compiler.Properties.Cflags)
	CheckBadCompilerFlags(ctx, "cppflags", compiler.Properties.Cppflags)
	CheckBadCompilerFlags(ctx, "conlyflags", compiler.Properties.Conlyflags)
	CheckBadCompilerFlags(ctx, "asflags", compiler.Properties.Asflags)
	CheckBadCompilerFlags(ctx, "vendor.cflags", compiler.Properties.Target.Vendor.Cflags)
	CheckBadCompilerFlags(ctx, "recovery.cflags", compiler.Properties.Target.Recovery.Cflags)

	esc := proptools.NinjaAndShellEscape

	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Cflags)...)
	flags.CppFlags = append(flags.CppFlags, esc(compiler.Properties.Cppflags)...)
	flags.ConlyFlags = append(flags.ConlyFlags, esc(compiler.Properties.Conlyflags)...)
	flags.AsFlags = append(flags.AsFlags, esc(compiler.Properties.Asflags)...)
	flags.YasmFlags = append(flags.YasmFlags, esc(compiler.Properties.Asflags)...)
	flags.YaccFlags = append(flags.YaccFlags, esc(compiler.Properties.Yaccflags)...)

	// Include dir cflags
	localIncludeDirs := android.PathsForModuleSrc(ctx, compiler.Properties.Local_include_dirs)
	if len(localIncludeDirs) > 0 {
	f := includeDirsToFlags(localIncludeDirs)
	flags.GlobalFlags = append(flags.GlobalFlags, f)
	flags.YasmFlags = append(flags.YasmFlags, f)
	}
	rootIncludeDirs := android.PathsForSource(ctx, compiler.Properties.Include_dirs)
	if len(rootIncludeDirs) > 0 {
	f := includeDirsToFlags(rootIncludeDirs)
	flags.GlobalFlags = append(flags.GlobalFlags, f)
	flags.YasmFlags = append(flags.YasmFlags, f)
	}

	if compiler.Properties.Include_build_directory == nil \|\|
	*compiler.Properties.Include_build_directory {
	flags.GlobalFlags = append(flags.GlobalFlags, "-I"+android.PathForModuleSrc(ctx).String())
	flags.YasmFlags = append(flags.YasmFlags, "-I"+android.PathForModuleSrc(ctx).String())
	}

	if !(ctx.useSdk() \|\| ctx.useVndk()) \|\| ctx.Host() {
	flags.SystemIncludeFlags = append(flags.SystemIncludeFlags,
	"${config.CommonGlobalIncludes}",
	tc.IncludeFlags(),
	"${config.CommonNativehelperInclude}")
	}

	if ctx.useSdk() {
	// TODO: Switch to --sysroot.
	// 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
	// behavior here, and the NDK always has all the NDK headers available.
	flags.SystemIncludeFlags = append(flags.SystemIncludeFlags,
	"-isystem "+getCurrentIncludePath(ctx).String(),
	"-isystem "+getCurrentIncludePath(ctx).Join(ctx, config.NDKTriple(tc)).String())

	// TODO: Migrate to API suffixed triple?
	// Traditionally this has come from android/api-level.h, but with the
	// libc headers unified it must be set by the build system since we
	// don't have per-API level copies of that header now.
	version := ctx.sdkVersion()
	if version == "current" {
	version = "__ANDROID_API_FUTURE__"
	}
	flags.GlobalFlags = append(flags.GlobalFlags,
	"-D__ANDROID_API__="+version)
	}

	if ctx.useVndk() {
	// sdkVersion() returns VNDK version for vendor modules.
	version := ctx.sdkVersion()
	if version == "current" {
	version = "__ANDROID_API_FUTURE__"
	}
	flags.GlobalFlags = append(flags.GlobalFlags,
	"-D__ANDROID_API__="+version, "-D__ANDROID_VNDK__")
	}

	if ctx.inRecovery() {
	flags.GlobalFlags = append(flags.GlobalFlags, "-D__ANDROID_RECOVERY__")
	}

	if ctx.apexName() != "" {
	flags.GlobalFlags = append(flags.GlobalFlags, "-D__ANDROID_APEX__="+ctx.apexName())
	}

	instructionSet := String(compiler.Properties.Instruction_set)
	if flags.RequiredInstructionSet != "" {
	instructionSet = flags.RequiredInstructionSet
	}
	instructionSetFlags, err := tc.ClangInstructionSetFlags(instructionSet)
	if err != nil {
	ctx.ModuleErrorf("%s", err)
	}

	CheckBadCompilerFlags(ctx, "release.cflags", compiler.Properties.Release.Cflags)

	// TODO: debug
	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Release.Cflags)...)

	CheckBadCompilerFlags(ctx, "clang_cflags", compiler.Properties.Clang_cflags)
	CheckBadCompilerFlags(ctx, "clang_asflags", compiler.Properties.Clang_asflags)

	flags.CFlags = config.ClangFilterUnknownCflags(flags.CFlags)
	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Clang_cflags)...)
	flags.AsFlags = append(flags.AsFlags, esc(compiler.Properties.Clang_asflags)...)
	flags.CppFlags = config.ClangFilterUnknownCflags(flags.CppFlags)
	flags.ConlyFlags = config.ClangFilterUnknownCflags(flags.ConlyFlags)
	flags.LdFlags = config.ClangFilterUnknownCflags(flags.LdFlags)

	target := "-target " + tc.ClangTriple()
	gccPrefix := "-B" + config.ToolPath(tc)

	flags.CFlags = append(flags.CFlags, target, gccPrefix)
	flags.AsFlags = append(flags.AsFlags, target, gccPrefix)
	flags.LdFlags = append(flags.LdFlags, target, gccPrefix)

	hod := "Host"
	if ctx.Os().Class == android.Device {
	hod = "Device"
	}

	flags.GlobalFlags = append(flags.GlobalFlags, instructionSetFlags)
	flags.ConlyFlags = append([]string{"${config.CommonGlobalConlyflags}"}, flags.ConlyFlags...)
	flags.CppFlags = append([]string{fmt.Sprintf("${config.%sGlobalCppflags}", hod)}, flags.CppFlags...)

	flags.AsFlags = append(flags.AsFlags, tc.ClangAsflags())
	flags.CppFlags = append([]string{"${config.CommonClangGlobalCppflags}"}, flags.CppFlags...)
	flags.GlobalFlags = append(flags.GlobalFlags,
	tc.ClangCflags(),
	"${config.CommonClangGlobalCflags}",
	fmt.Sprintf("${config.%sClangGlobalCflags}", hod))

	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
	flags.GlobalFlags = append([]string{"${config.ClangExternalCflags}"}, flags.GlobalFlags...)
	}

	if tc.Bionic() {
	if Bool(compiler.Properties.Rtti) {
	flags.CppFlags = append(flags.CppFlags, "-frtti")
	} else {
	flags.CppFlags = append(flags.CppFlags, "-fno-rtti")
	}
	}

	flags.AsFlags = append(flags.AsFlags, "-D__ASSEMBLY__")

	flags.CppFlags = append(flags.CppFlags, tc.ClangCppflags())

	flags.YasmFlags = append(flags.YasmFlags, tc.YasmFlags())

	flags.GlobalFlags = append(flags.GlobalFlags, tc.ToolchainClangCflags())

	cStd := config.CStdVersion
	if String(compiler.Properties.C_std) == "experimental" {
	cStd = config.ExperimentalCStdVersion
	} else if String(compiler.Properties.C_std) != "" {
	cStd = String(compiler.Properties.C_std)
	}

	cppStd := String(compiler.Properties.Cpp_std)
	switch String(compiler.Properties.Cpp_std) {
	case "":
	cppStd = config.CppStdVersion
	case "experimental":
	cppStd = config.ExperimentalCppStdVersion
	}

	if compiler.Properties.Gnu_extensions != nil && *compiler.Properties.Gnu_extensions == false {
	cStd = gnuToCReplacer.Replace(cStd)
	cppStd = gnuToCReplacer.Replace(cppStd)
	}

	flags.ConlyFlags = append([]string{"-std=" + cStd}, flags.ConlyFlags...)
	flags.CppFlags = append([]string{"-std=" + cppStd}, flags.CppFlags...)

	if ctx.useVndk() {
	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Target.Vendor.Cflags)...)
	}

	if ctx.inRecovery() {
	flags.CFlags = append(flags.CFlags, esc(compiler.Properties.Target.Recovery.Cflags)...)
	}

	// We can enforce some rules more strictly in the code we own. strict
	// indicates if this is code that we can be stricter with. If we have
	// rules that we want to apply to our code (but maybe can't for
	// vendor/device specific things), we could extend this to be a ternary
	// value.
	strict := true
	if strings.HasPrefix(android.PathForModuleSrc(ctx).String(), "external/") {
	strict = false
	}

	// Can be used to make some annotations stricter for code we can fix
	// (such as when we mark functions as deprecated).
	if strict {
	flags.CFlags = append(flags.CFlags, "-DANDROID_STRICT")
	}

	if compiler.hasSrcExt(".proto") {
	flags = protoFlags(ctx, flags, &compiler.Proto)
	}

	if compiler.hasSrcExt(".y") \|\| compiler.hasSrcExt(".yy") {
	flags.GlobalFlags = append(flags.GlobalFlags,
	"-I"+android.PathForModuleGen(ctx, "yacc", ctx.ModuleDir()).String())
	}

	if compiler.hasSrcExt(".mc") {
	flags.GlobalFlags = append(flags.GlobalFlags,
	"-I"+android.PathForModuleGen(ctx, "windmc", ctx.ModuleDir()).String())
	}

	if compiler.hasSrcExt(".aidl") {
	if len(compiler.Properties.Aidl.Local_include_dirs) > 0 {
	localAidlIncludeDirs := android.PathsForModuleSrc(ctx, compiler.Properties.Aidl.Local_include_dirs)
	flags.aidlFlags = append(flags.aidlFlags, includeDirsToFlags(localAidlIncludeDirs))
	}
	if len(compiler.Properties.Aidl.Include_dirs) > 0 {
	rootAidlIncludeDirs := android.PathsForSource(ctx, compiler.Properties.Aidl.Include_dirs)
	flags.aidlFlags = append(flags.aidlFlags, includeDirsToFlags(rootAidlIncludeDirs))
	}

	if Bool(compiler.Properties.Aidl.Generate_traces) {
	flags.aidlFlags = append(flags.aidlFlags, "-t")
	}

	flags.GlobalFlags = append(flags.GlobalFlags,
	"-I"+android.PathForModuleGen(ctx, "aidl").String())
	}

	if compiler.hasSrcExt(".rs") \|\| compiler.hasSrcExt(".fs") {
	flags = rsFlags(ctx, flags, &compiler.Properties)
	}

	if compiler.hasSrcExt(".sysprop") {
	flags.GlobalFlags = append(flags.GlobalFlags,
	"-I"+android.PathForModuleGen(ctx, "sysprop", "include").String())
	}

	if len(compiler.Properties.Srcs) > 0 {
	module := ctx.ModuleDir() + "/Android.bp:" + ctx.ModuleName()
	if inList("-Wno-error", flags.CFlags) \|\| inList("-Wno-error", flags.CppFlags) {
	addToModuleList(ctx, modulesUsingWnoErrorKey, module)
	} else if !inList("-Werror", flags.CFlags) && !inList("-Werror", flags.CppFlags) {
	if warningsAreAllowed(ctx.ModuleDir()) {
	addToModuleList(ctx, modulesAddedWallKey, module)
	flags.CFlags = append([]string{"-Wall"}, flags.CFlags...)
	} else {
	flags.CFlags = append([]string{"-Wall", "-Werror"}, flags.CFlags...)
	}
	}
	}

	if Bool(compiler.Properties.Openmp) {
	flags.CFlags = append(flags.CFlags, "-fopenmp")
	}

	return flags
	}

	func (compiler *baseCompiler) hasSrcExt(ext string) bool {
	for _, src := range compiler.srcsBeforeGen {
	if src.Ext() == ext {
	return true
	}
	}
	for _, src := range compiler.Properties.Srcs {
	if filepath.Ext(src) == ext {
	return true
	}
	}
	for _, src := range compiler.Properties.OriginalSrcs {
	if filepath.Ext(src) == ext {
	return true
	}
	}

	return false
	}

	var gnuToCReplacer = strings.NewReplacer("gnu", "c")

	func ndkPathDeps(ctx ModuleContext) android.Paths {
	if ctx.useSdk() {
	// The NDK sysroot timestamp file depends on all the NDK sysroot files
	// (headers and libraries).
	return android.Paths{getNdkBaseTimestampFile(ctx)}
	}
	return nil
	}

	func (compiler *baseCompiler) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
	pathDeps := deps.GeneratedHeaders
	pathDeps = append(pathDeps, ndkPathDeps(ctx)...)

	buildFlags := flagsToBuilderFlags(flags)

	srcs := append(android.Paths(nil), compiler.srcsBeforeGen...)

	srcs, genDeps := genSources(ctx, srcs, buildFlags)
	pathDeps = append(pathDeps, genDeps...)

	compiler.pathDeps = pathDeps
	compiler.cFlagsDeps = flags.CFlagsDeps

	// Save src, buildFlags and context
	compiler.srcs = srcs

	// Compile files listed in c.Properties.Srcs into objects
	objs := compileObjs(ctx, buildFlags, "", srcs, pathDeps, compiler.cFlagsDeps)

	if ctx.Failed() {
	return Objects{}
	}

	return objs
	}

	// Compile a list of source files into objects a specified subdirectory
	func compileObjs(ctx android.ModuleContext, flags builderFlags,
	subdir string, srcFiles, pathDeps android.Paths, cFlagsDeps android.Paths) Objects {

	return TransformSourceToObj(ctx, subdir, srcFiles, flags, pathDeps, cFlagsDeps)
	}