Allow debugging with SOONG_DELVE=<listen addr>
Allow running Soong in a headless delve debugger by passing
SOONG_DELVE=<listen addr> in the environment.
Bug: 80165685
Test: SOONG_DELVE=:1234 m nothing
Change-Id: Icfc893c8a8354a9bbc99112d9c83259cb41906d1
diff --git a/README.md b/README.md
index ebbe8bc..531ef4c 100644
--- a/README.md
+++ b/README.md
@@ -337,6 +337,19 @@
This will bind mount the Soong source directories into the directory in the layout expected by
the IDE.
+### Running Soong in a debugger
+
+To run the soong_build process in a debugger, install `dlv` and then start the build with
+`SOONG_DELVE=<listen addr>` in the environment.
+For examle:
+```bash
+SOONG_DELVE=:1234 m nothing
+```
+and then in another terminal:
+```
+dlv connect :1234
+```
+
## Contact
Email android-building@googlegroups.com (external) for any questions, or see
diff --git a/android/env.go b/android/env.go
index 469dfff..d9f2db2 100644
--- a/android/env.go
+++ b/android/env.go
@@ -16,6 +16,7 @@
import (
"os"
+ "os/exec"
"strings"
"android/soong/env"
@@ -29,8 +30,16 @@
// a manifest regeneration.
var originalEnv map[string]string
+var SoongDelveListen string
+var SoongDelvePath 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")
+
originalEnv = make(map[string]string)
for _, env := range os.Environ() {
idx := strings.IndexRune(env, '=')
@@ -38,6 +47,8 @@
originalEnv[env[:idx]] = env[idx+1:]
}
}
+ // 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()
}
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index 41c7d46..30381e0 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -18,7 +18,12 @@
"flag"
"fmt"
"os"
+ "os/exec"
"path/filepath"
+ "strconv"
+ "strings"
+ "syscall"
+ "time"
"github.com/google/blueprint/bootstrap"
@@ -50,6 +55,42 @@
}
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)
+ }
+ }
+
flag.Parse()
// The top-level Blueprints file is passed as the first argument.
@@ -72,7 +113,17 @@
ctx.SetAllowMissingDependencies(configuration.AllowMissingDependencies())
- bootstrap.Main(ctx.Context, configuration, configuration.ConfigFileName, configuration.ProductVariablesFileName)
+ extraNinjaDeps := []string{configuration.ConfigFileName, configuration.ProductVariablesFileName}
+
+ // Read the SOONG_DELVE again through configuration so that there is a dependency on the environment variable
+ // and soong_build will rerun when it is set for the first time.
+ if listen := configuration.Getenv("SOONG_DELVE"); listen != "" {
+ // Add a non-existent file to the dependencies so that soong_build will rerun when the debugger is
+ // enabled even if it completed successfully.
+ extraNinjaDeps = append(extraNinjaDeps, filepath.Join(configuration.BuildDir(), "always_rerun_for_delve"))
+ }
+
+ bootstrap.Main(ctx.Context, configuration, extraNinjaDeps...)
if docFile != "" {
if err := writeDocs(ctx, docFile); err != nil {
diff --git a/ui/build/paths/config.go b/ui/build/paths/config.go
index e2c5043..a4be2ac 100644
--- a/ui/build/paths/config.go
+++ b/ui/build/paths/config.go
@@ -81,6 +81,7 @@
"bzip2": Allowed,
"dd": Allowed,
"diff": Allowed,
+ "dlv": Allowed,
"egrep": Allowed,
"expr": Allowed,
"find": Allowed,
diff --git a/ui/build/sandbox_linux.go b/ui/build/sandbox_linux.go
index b94db74..11ff667 100644
--- a/ui/build/sandbox_linux.go
+++ b/ui/build/sandbox_linux.go
@@ -162,6 +162,10 @@
c.ctx.Printf("AllowBuildBrokenUsesNetwork: %v", c.Sandbox.AllowBuildBrokenUsesNetwork)
c.ctx.Printf("BuildBrokenUsesNetwork: %v", c.config.BuildBrokenUsesNetwork())
sandboxArgs = append(sandboxArgs, "-N")
+ } else if dlv, _ := c.config.Environment().Get("SOONG_DELVE"); dlv != "" {
+ // The debugger is enabled and soong_build will pause until a remote delve process connects, allow
+ // network connections.
+ sandboxArgs = append(sandboxArgs, "-N")
}
// Stop nsjail from parsing arguments