Merge "Use a linker script for host bionic embedded linker sections" (956e32c1) · Commits · e / os / android_build_soong

Android.bp

+3 −3

Original line number	Diff line number	Diff line
		@@ -92,7 +92,7 @@ cc_genrule {
		}

		cc_genrule {
		name: "host_bionic_linker_flags",
		name: "host_bionic_linker_script",
		host_supported: true,
		device_supported: false,
		target: {
		@@ -107,9 +107,9 @@ cc_genrule {
		},
		},
		tools: ["extract_linker"],
		cmd: "$(location) -f $(out) $(in)",
		cmd: "$(location) -T $(out) $(in)",
		srcs: [":linker"],
		out: ["linker.flags"],
		out: ["linker.script"],
		}

		// Instantiate the dex_bootjars singleton module.

cc/binary.go

+1 −7

Original line number	Diff line number	Diff line
		@@ -178,7 +178,7 @@ func (binary *binaryDecorator) linkerDeps(ctx DepsContext, deps Deps) Deps {
		// the kernel before jumping to the embedded linker.
		if ctx.Os() == android.LinuxBionic && !binary.static() {
		deps.DynamicLinker = "linker"
		deps.LinkerFlagsFile = "host_bionic_linker_flags"
		deps.CrtBegin = append(deps.CrtBegin, "host_bionic_linker_script")
		}
		}

		@@ -345,12 +345,6 @@ func (binary *binaryDecorator) link(ctx ModuleContext,

		var linkerDeps android.Paths

		// Add flags from linker flags file.
		if deps.LinkerFlagsFile.Valid() {
		flags.Local.LdFlags = append(flags.Local.LdFlags, "$$(cat "+deps.LinkerFlagsFile.String()+")")
		linkerDeps = append(linkerDeps, deps.LinkerFlagsFile.Path())
		}

		if flags.DynamicLinker != "" {
		flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-dynamic-linker,"+flags.DynamicLinker)
		} else if ctx.toolchain().Bionic() && !binary.static() {

cc/cc.go

+1 −20

Original line number	Diff line number	Diff line
		@@ -129,7 +129,6 @@ type Deps struct {
		CrtBegin, CrtEnd []string

		// Used for host bionic
		LinkerFlagsFile string
		DynamicLinker string

		// List of libs that need to be excluded for APEX variant
		@@ -179,9 +178,6 @@ type PathDeps struct {
		// Paths to crt*.o files
		CrtBegin, CrtEnd android.Paths

		// Path to the file container flags to use with the linker
		LinkerFlagsFile android.OptionalPath

		// Path to the dynamic linker binary
		DynamicLinker android.OptionalPath
		}
		@@ -726,7 +722,6 @@ var (
		genHeaderDepTag = dependencyTag{name: "gen header"}
		genHeaderExportDepTag = dependencyTag{name: "gen header export"}
		objDepTag = dependencyTag{name: "obj"}
		linkerFlagsDepTag = dependencyTag{name: "linker flags file"}
		dynamicLinkerDepTag = installDependencyTag{name: "dynamic linker"}
		reuseObjTag = dependencyTag{name: "reuse objects"}
		staticVariantTag = dependencyTag{name: "static variant"}
		@@ -2272,9 +2267,6 @@ func (c *Module) DepsMutator(actx android.BottomUpMutatorContext) {
		actx.AddVariationDependencies(crtVariations, CrtEndDepTag,
		RewriteSnapshotLib(crt, GetSnapshot(c, &snapshotInfo, actx).Objects))
		}
		if deps.LinkerFlagsFile != "" {
		actx.AddDependency(c, linkerFlagsDepTag, deps.LinkerFlagsFile)
		}
		if deps.DynamicLinker != "" {
		actx.AddDependency(c, dynamicLinkerDepTag, deps.DynamicLinker)
		}
		@@ -2573,17 +2565,6 @@ func (c *Module) depsToPaths(ctx android.ModuleContext) PathDeps {
		} else {
		ctx.ModuleErrorf("module %q is not a genrule", depName)
		}
		case linkerFlagsDepTag:
		if genRule, ok := dep.(genrule.SourceFileGenerator); ok {
		files := genRule.GeneratedSourceFiles()
		if len(files) == 1 {
		depPaths.LinkerFlagsFile = android.OptionalPathForPath(files[0])
		} else if len(files) > 1 {
		ctx.ModuleErrorf("module %q can only generate a single file if used for a linker flag file", depName)
		}
		} else {
		ctx.ModuleErrorf("module %q is not a genrule", depName)
		}
		case CrtBeginDepTag:
		depPaths.CrtBegin = append(depPaths.CrtBegin, android.OutputFileForModule(ctx, dep, ""))
		case CrtEndDepTag:

cc/testing.go

+2 −2

Original line number	Diff line number	Diff line
		@@ -490,7 +490,7 @@ func withLinuxBionic() string {
		}

		cc_genrule {
		name: "host_bionic_linker_flags",
		name: "host_bionic_linker_script",
		host_supported: true,
		device_supported: false,
		target: {
		@@ -501,7 +501,7 @@ func withLinuxBionic() string {
		enabled: true,
		},
		},
		out: ["linker.flags"],
		out: ["linker.script"],
		}

		cc_defaults {

cmd/extract_linker/main.go

+16 −12

Original line number	Diff line number	Diff line
		@@ -13,7 +13,7 @@
		// limitations under the License.

		// This tool extracts ELF LOAD segments from our linker binary, and produces an
		// assembly file and linker flags which will embed those segments as sections
		// assembly file and linker script which will embed those segments as sections
		// in another binary.
		package main

		@@ -31,10 +31,10 @@ import (

		func main() {
		var asmPath string
		var flagsPath string
		var scriptPath string

		flag.StringVar(&asmPath, "s", "", "Path to save the assembly file")
		flag.StringVar(&flagsPath, "f", "", "Path to save the linker flags")
		flag.StringVar(&scriptPath, "T", "", "Path to save the linker script")
		flag.Parse()

		f, err := os.Open(flag.Arg(0))
		@@ -49,13 +49,16 @@ func main() {
		}

		asm := &bytes.Buffer{}
		script := &bytes.Buffer{}
		baseLoadAddr := uint64(0x1000)
		load := 0
		linkFlags := []string{}

		fmt.Fprintln(asm, ".globl __dlwrap_linker_offset")
		fmt.Fprintf(asm, ".set __dlwrap_linker_offset, 0x%x\n", baseLoadAddr)

		fmt.Fprintln(script, "ENTRY(__dlwrap__start)")
		fmt.Fprintln(script, "SECTIONS {")

		for _, prog := range ef.Progs {
		if prog.Type != elf.PT_LOAD {
		continue
		@@ -82,10 +85,9 @@ func main() {

		fmt.Fprintf(asm, ".globl %s\n%s:\n\n", symName, symName)

		linkFlags = append(linkFlags,
		fmt.Sprintf("-Wl,--undefined=%s", symName),
		fmt.Sprintf("-Wl,--section-start=%s=0x%x",
		sectionName, baseLoadAddr+prog.Vaddr))
		fmt.Fprintf(script, " %s %d : {\n", sectionName, baseLoadAddr+prog.Vaddr)
		fmt.Fprintf(script, " KEEP(*(%s));\n", sectionName)
		fmt.Fprintln(script, " }")

		buffer, _ := ioutil.ReadAll(prog.Open())
		bytesToAsm(asm, buffer)
		@@ -104,16 +106,18 @@ func main() {
		load += 1
		}

		fmt.Fprintln(script, "}")
		fmt.Fprintln(script, "INSERT BEFORE .note.android.ident;")

		if asmPath != "" {
		if err := ioutil.WriteFile(asmPath, asm.Bytes(), 0777); err != nil {
		log.Fatalf("Unable to write %q: %v", asmPath, err)
		}
		}

		if flagsPath != "" {
		flags := strings.Join(linkFlags, " ")
		if err := ioutil.WriteFile(flagsPath, []byte(flags), 0777); err != nil {
		log.Fatalf("Unable to write %q: %v", flagsPath, err)
		if scriptPath != "" {
		if err := ioutil.WriteFile(scriptPath, script.Bytes(), 0777); err != nil {
		log.Fatalf("Unable to write %q: %v", scriptPath, err)
		}
		}
		}