[lldb][AIX] Host.cpp for AIX

[DhruvSrivastavaX]

This PR is in reference to porting LLDB on AIX.

Link to discussions on llvm discourse and github:

1. https://discourse.llvm.org/t/port-lldb-to-ibm-aix/80640
2. Extending LLDB to work on AIX #101657
   The complete changes for porting are present in this draft PR:
   Extending LLDB to work on AIX #102601

Added base file - aix/Host.cpp for Process info

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Dhruv Srivastava (DhruvSrivastavaX)

Changes

This PR is in reference to porting LLDB on AIX.

Link to discussions on llvm discourse and github:

1. https://discourse.llvm.org/t/port-lldb-to-ibm-aix/80640
2. Extending LLDB to work on AIX #101657
   The complete changes for porting are present in this draft PR:
   Extending LLDB to work on AIX #102601

Added base file - aix/Host.cpp for Process info

---

Full diff: https://github.com/llvm/llvm-project/pull/130582.diff

2 Files Affected:

• (modified) lldb/source/Host/CMakeLists.txt (+1)
• (added) lldb/source/Host/aix/Host.cpp (+109)

diff --git a/lldb/source/Host/CMakeLists.txt b/lldb/source/Host/CMakeLists.txt
index 9be0c06a516ba..52ef67feeb6ab 100644
--- a/lldb/source/Host/CMakeLists.txt
+++ b/lldb/source/Host/CMakeLists.txt
@@ -135,6 +135,7 @@ else()
 
   elseif (CMAKE_SYSTEM_NAME MATCHES "AIX")
     add_host_subdirectory(aix
+      aix/Host.cpp
       aix/HostInfoAIX.cpp
       )
   endif()
diff --git a/lldb/source/Host/aix/Host.cpp b/lldb/source/Host/aix/Host.cpp
new file mode 100644
index 0000000000000..38c77b4959ead
--- /dev/null
+++ b/lldb/source/Host/aix/Host.cpp
@@ -0,0 +1,109 @@
+//===-- source/Host/aix/Host.cpp ----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Host/Host.h"
+#include "lldb/Utility/ProcessInfo.h"
+#include "lldb/Utility/Status.h"
+#include <dirent.h>
+
+using namespace llvm;
+using namespace lldb;
+using namespace lldb_private;
+
+namespace {
+enum class ProcessState {
+  Unknown,
+  Dead,
+  DiskSleep,
+  Idle,
+  Paging,
+  Parked,
+  Running,
+  Sleeping,
+  TracedOrStopped,
+  Zombie,
+};
+}
+
+namespace lldb_private {
+class ProcessLaunchInfo;
+}
+
+static bool GetStatusInfo(::pid_t Pid, ProcessInstanceInfo &ProcessInfo,
+                          ProcessState &State, ::pid_t &TracerPid,
+                          ::pid_t &Tgid) {
+  return false;
+}
+
+static void GetProcessArgs(::pid_t pid, ProcessInstanceInfo &process_info) {}
+
+static bool GetProcessAndStatInfo(::pid_t pid,
+                                  ProcessInstanceInfo &process_info,
+                                  ProcessState &State, ::pid_t &tracerpid) {
+  return false;
+}
+
+uint32_t Host::FindProcessesImpl(const ProcessInstanceInfoMatch &match_info,
+                                 ProcessInstanceInfoList &process_infos) {
+  static const char procdir[] = "/proc/";
+
+  DIR *dirproc = opendir(procdir);
+  if (dirproc) {
+    struct dirent *direntry = nullptr;
+    const uid_t our_uid = getuid();
+    const lldb::pid_t our_pid = getpid();
+    bool all_users = match_info.GetMatchAllUsers();
+
+    while ((direntry = readdir(dirproc)) != nullptr) {
+
+      lldb::pid_t pid = atoi(direntry->d_name);
+
+      // Skip this process.
+      if (pid == our_pid)
+        continue;
+
+      ::pid_t tracerpid;
+      ProcessState State;
+      ProcessInstanceInfo process_info;
+
+      if (!GetProcessAndStatInfo(pid, process_info, State, tracerpid))
+        continue;
+
+      // Skip if process is being debugged.
+      if (tracerpid != 0)
+        continue;
+
+      if (State == ProcessState::Zombie)
+        continue;
+
+      // Check for user match if we're not matching all users and not running
+      // as root.
+      if (!all_users && (our_uid != 0) && (process_info.GetUserID() != our_uid))
+        continue;
+
+      if (match_info.Matches(process_info))
+        process_infos.push_back(process_info);
+    }
+
+    closedir(dirproc);
+  }
+
+  return process_infos.size();
+}
+
+bool Host::GetProcessInfo(lldb::pid_t pid, ProcessInstanceInfo &process_info) {
+  ::pid_t tracerpid;
+  ProcessState State;
+  return GetProcessAndStatInfo(pid, process_info, State, tracerpid);
+}
+
+Environment Host::GetEnvironment() { return Environment(environ); }
+
+Status Host::ShellExpandArguments(ProcessLaunchInfo &launch_info) {
+  return Status("unimplemented");
+}