[Lldb-commits] [lldb] support attaching by name for platform android (PR #160931)

[Walter Erquinigo via lldb-commits]

================
@@ -477,6 +477,248 @@ std::string PlatformAndroid::GetRunAs() {
   }
   return run_as.str();
 }
+
+// Helper function to populate process status information from
+// /proc/[pid]/status
+void PlatformAndroid::PopulateProcessStatusInfo(
+    lldb::pid_t pid, ProcessInstanceInfo &process_info) {
+  // Read /proc/[pid]/status to get parent PID, UIDs, and GIDs
+  Status error;
+  auto status_adb = GetAdbClient(error);
+  if (error.Fail())
+    return;
+
+  std::string status_output;
+  StreamString status_cmd;
+  status_cmd.Printf(
+      "cat /proc/%llu/status 2>/dev/null | grep -E '^(PPid|Uid|Gid):'",
+      (unsigned long long)pid);
+  Status status_error =
+      status_adb->Shell(status_cmd.GetData(), seconds(5), &status_output);
+
+  if (status_error.Fail() || status_output.empty())
+    return;
+
+  llvm::SmallVector<llvm::StringRef, 16> lines;
+  llvm::StringRef(status_output).split(lines, '\n');
+
+  for (llvm::StringRef line : lines) {
+    line = line.trim();
+    if (line.starts_with("PPid:")) {
+      llvm::StringRef ppid_str = line.substr(5).trim();
+      lldb::pid_t ppid;
+      if (llvm::to_integer(ppid_str, ppid))
+        process_info.SetParentProcessID(ppid);
+    } else if (line.starts_with("Uid:")) {
+      llvm::SmallVector<llvm::StringRef, 4> uid_parts;
+      line.substr(4).trim().split(uid_parts, '\t', -1, false);
+      if (uid_parts.size() >= 2) {
+        uint32_t uid, euid;
+        if (llvm::to_integer(uid_parts[0].trim(), uid))
+          process_info.SetUserID(uid);
+        if (llvm::to_integer(uid_parts[1].trim(), euid))
+          process_info.SetEffectiveUserID(euid);
+      }
+    } else if (line.starts_with("Gid:")) {
+      llvm::SmallVector<llvm::StringRef, 4> gid_parts;
+      line.substr(4).trim().split(gid_parts, '\t', -1, false);
+      if (gid_parts.size() >= 2) {
+        uint32_t gid, egid;
+        if (llvm::to_integer(gid_parts[0].trim(), gid))
+          process_info.SetGroupID(gid);
+        if (llvm::to_integer(gid_parts[1].trim(), egid))
+          process_info.SetEffectiveGroupID(egid);
+      }
+    }
+  }
+}
+
+// Helper function to populate command line arguments from /proc/[pid]/cmdline
+void PlatformAndroid::PopulateProcessCommandLine(
+    lldb::pid_t pid, ProcessInstanceInfo &process_info) {
+  // Read /proc/[pid]/cmdline to get command line arguments
+  Status error;
+  auto cmdline_adb = GetAdbClient(error);
+  if (error.Fail())
+    return;
+
+  std::string cmdline_output;
+  StreamString cmdline_cmd;
+  cmdline_cmd.Printf("cat /proc/%llu/cmdline 2>/dev/null | tr '\\000' ' '",
+                     (unsigned long long)pid);
+  Status cmdline_error =
+      cmdline_adb->Shell(cmdline_cmd.GetData(), seconds(5), &cmdline_output);
+
+  if (cmdline_error.Fail() || cmdline_output.empty())
+    return;
+
+  cmdline_output = llvm::StringRef(cmdline_output).trim().str();
+  if (cmdline_output.empty())
+    return;
+
+  llvm::SmallVector<llvm::StringRef, 16> args;
+  llvm::StringRef(cmdline_output).split(args, ' ', -1, false);
+  if (args.empty())
+    return;
+
+  process_info.SetArg0(args[0]);
+  Args process_args;
+  for (size_t i = 1; i < args.size(); i++) {
+    if (!args[i].empty())
+      process_args.AppendArgument(args[i]);
+  }
+  process_info.SetArguments(process_args, false);
+}
+
+// Helper function to populate architecture from /proc/[pid]/exe
+void PlatformAndroid::PopulateProcessArchitecture(
+    lldb::pid_t pid, ProcessInstanceInfo &process_info) {
+  // Read /proc/[pid]/exe to get executable path for architecture detection
+  Status error;
+  auto exe_adb = GetAdbClient(error);
+  if (error.Fail())
+    return;
+
+  std::string exe_output;
+  StreamString exe_cmd;
+  exe_cmd.Printf("readlink /proc/%llu/exe 2>/dev/null",
+                 (unsigned long long)pid);
+  Status exe_error = exe_adb->Shell(exe_cmd.GetData(), seconds(5), &exe_output);
+
+  if (exe_error.Fail() || exe_output.empty())
+    return;
+
+  exe_output = llvm::StringRef(exe_output).trim().str();
+
+  // Determine architecture from exe path
+  ArchSpec arch;
+  if (exe_output.find("64") != std::string::npos ||
+      exe_output.find("arm64") != std::string::npos ||
+      exe_output.find("aarch64") != std::string::npos) {
+    arch.SetTriple("aarch64-unknown-linux-android");
+  } else if (exe_output.find("x86_64") != std::string::npos) {
+    arch.SetTriple("x86_64-unknown-linux-android");
+  } else if (exe_output.find("x86") != std::string::npos ||
+             exe_output.find("i686") != std::string::npos) {
+    arch.SetTriple("i686-unknown-linux-android");
+  } else {
+    // Default to armv7 for 32-bit ARM (most common on Android)
+    arch.SetTriple("armv7-unknown-linux-android");
+  }
+
+  if (arch.IsValid())
+    process_info.SetArchitecture(arch);
+}
+
+uint32_t
+PlatformAndroid::FindProcesses(const ProcessInstanceInfoMatch &match_info,
+                               ProcessInstanceInfoList &proc_infos) {
+  proc_infos.clear();
+
+  // When LLDB is running natively on an Android device (IsHost() == true),
+  // use the parent class's standard Linux /proc enumeration. IsHost() is only
+  // true when compiled for Android (#if defined(__ANDROID__)), so calling
+  // PlatformLinux methods is safe (Android is Linux-based).
+  if (IsHost())
+    return PlatformLinux::FindProcesses(match_info, proc_infos);
+
+  // Remote Android platform: implement process name lookup using 'pidof' over
+  // adb.
+
+  // LLDB stores the search name in GetExecutableFile() (even though it's
+  // actually a process name like "com.android.chrome" rather than an
+  // executable path). If no search name is provided, we can't use
+  // 'pidof', so return early with no results.
+  const ProcessInstanceInfo &match_process_info = match_info.GetProcessInfo();
+  if (!match_process_info.GetExecutableFile() ||
+      match_info.GetNameMatchType() == NameMatch::Ignore) {
+    return 0;
+  }
+
+  // Extract the process name to search for (typically an Android package name
+  // like "com.example.app" or binary name like "app_process64")
+  std::string process_name = match_process_info.GetExecutableFile().GetPath();
+  if (process_name.empty())
+    return 0;
+
+  // Use adb to find the process by name
+  Status error;
+  AdbClientUP adb(GetAdbClient(error));
+  if (error.Fail()) {
+    Log *log = GetLog(LLDBLog::Platform);
+    LLDB_LOGF(log, "PlatformAndroid::%s failed to get ADB client: %s",
+              __FUNCTION__, error.AsCString());
+    return 0;
+  }
+
+  // Use 'pidof' command to get PIDs for the process name.
+  // Quote the process name to handle special characters (spaces, etc.)
+  std::string pidof_output;
+  StreamString command;
+  command.Printf("pidof '%s'", process_name.c_str());
+  error = adb->Shell(command.GetData(), seconds(5), &pidof_output);
+
+  if (error.Fail()) {
+    Log *log = GetLog(LLDBLog::Platform);
+    LLDB_LOGF(log, "PlatformAndroid::%s 'pidof %s' failed: %s", __FUNCTION__,
----------------
walter-erquinigo wrote:

`LLDB_LOG` is actually simpler because is used `{}` instead of `%`, but up to you

https://github.com/llvm/llvm-project/pull/160931