Merge "Call Delve using exec() instead of "dlv attach"." am: ad37304762 (bb751686) · Commits · e / os / android_build_soong

android/env.go

+37 −4

Original line number	Diff line number	Diff line
		@@ -15,9 +15,11 @@
		package android

		import (
		"fmt"
		"os"
		"os/exec"
		"strings"
		"syscall"

		"android/soong/env"
		)
		@@ -30,28 +32,59 @@ import (
		// a manifest regeneration.

		var originalEnv map[string]string
		var SoongDelveListen string
		var SoongDelvePath string
		var soongDelveListen string
		var soongDelvePath string
		var soongDelveEnv []string

		func init() {
		// Delve support needs to read this environment variable very early, before NewConfig has created a way to
		// access originalEnv with dependencies. Store the value where soong_build can find it, it will manually
		// ensure the dependencies are created.
		SoongDelveListen = os.Getenv("SOONG_DELVE")
		SoongDelvePath, _ = exec.LookPath("dlv")
		soongDelveListen = os.Getenv("SOONG_DELVE")
		soongDelvePath, _ = exec.LookPath("dlv")

		originalEnv = make(map[string]string)
		soongDelveEnv = []string{}
		for _, env := range os.Environ() {
		idx := strings.IndexRune(env, '=')
		if idx != -1 {
		originalEnv[env[:idx]] = env[idx+1:]
		if env[:idx] != "SOONG_DELVE" {
		soongDelveEnv = append(soongDelveEnv, env)
		}
		}
		}

		// Clear the environment to prevent use of os.Getenv(), which would not provide dependencies on environment
		// variable values. The environment is available through ctx.Config().Getenv, ctx.Config().IsEnvTrue, etc.
		os.Clearenv()
		}

		func ReexecWithDelveMaybe() {
		if soongDelveListen == "" {
		return
		}

		if soongDelvePath == "" {
		fmt.Fprintln(os.Stderr, "SOONG_DELVE is set but failed to find dlv")
		os.Exit(1)
		}
		dlvArgv := []string{
		soongDelvePath,
		"--listen=:" + soongDelveListen,
		"--headless=true",
		"--api-version=2",
		"exec",
		os.Args[0],
		"--",
		}
		dlvArgv = append(dlvArgv, os.Args[1:]...)
		os.Chdir(absSrcDir)
		syscall.Exec(soongDelvePath, dlvArgv, soongDelveEnv)
		fmt.Fprintln(os.Stderr, "exec() failed while trying to reexec with Delve")
		os.Exit(1)
		}

		// getenv checks either os.Getenv or originalEnv so that it works before or after the init()
		// function above. It doesn't add any dependencies on the environment variable, so it should
		// only be used for values that won't change. For values that might change use ctx.Config().Getenv.

cmd/soong_build/main.go

+1 −41

Original line number	Diff line number	Diff line
		@@ -18,12 +18,7 @@ import (
		"flag"
		"fmt"
		"os"
		"os/exec"
		"path/filepath"
		"strconv"
		"strings"
		"syscall"
		"time"

		"github.com/google/blueprint/bootstrap"

		@@ -55,42 +50,7 @@ func newNameResolver(config android.Config) *android.NameResolver {
		}

		func main() {
		if android.SoongDelveListen != "" {
		if android.SoongDelvePath == "" {
		fmt.Fprintln(os.Stderr, "SOONG_DELVE is set but failed to find dlv")
		os.Exit(1)
		}
		pid := strconv.Itoa(os.Getpid())
		cmd := []string{android.SoongDelvePath,
		"attach", pid,
		"--headless",
		"-l", android.SoongDelveListen,
		"--api-version=2",
		"--accept-multiclient",
		"--log",
		}

		fmt.Println("Starting", strings.Join(cmd, " "))
		dlv := exec.Command(cmd[0], cmd[1:]...)
		dlv.Stdout = os.Stdout
		dlv.Stderr = os.Stderr
		dlv.Stdin = nil

		// Put dlv into its own process group so we can kill it and the child process it starts.
		dlv.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}

		err := dlv.Start()
		if err != nil {
		// Print the error starting dlv and continue.
		fmt.Println(err)
		} else {
		// Kill the process group for dlv when soong_build exits.
		defer syscall.Kill(-dlv.Process.Pid, syscall.SIGKILL)
		// Wait to give dlv a chance to connect and pause the process.
		time.Sleep(time.Second)
		}
		}

		android.ReexecWithDelveMaybe()
		flag.Parse()

		// The top-level Blueprints file is passed as the first argument.