[Lldb-commits] [lldb] [lldb][AIX] AIX Changes for MainLoop polling (PR #120378)

[Dhruv Srivastava via lldb-commits]

https://github.com/DhruvSrivastavaX created https://github.com/llvm/llvm-project/pull/120378

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. https://github.com/llvm/llvm-project/issues/101657
The complete changes for porting are present in this draft PR:
https://github.com/llvm/llvm-project/pull/102601

Dropping changes for MainLoop polling in AIX, as `ppoll` is not supported in AIX currently. 
This change is part of the couple of minimal changes required to build a minimal `lldb` biniry on AIX

Review Request: @labath @DavidSpickett

>From cf6a863b6da6bdaf474d2abc4524960b6436f645 Mon Sep 17 00:00:00 2001
From: Dhruv-Srivastava <dhruv.srivastava at ibm.com>
Date: Wed, 18 Dec 2024 02:17:04 -0600
Subject: [PATCH] AIX Changes for MainLoop

---
 lldb/source/Host/posix/MainLoopPosix.cpp | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/lldb/source/Host/posix/MainLoopPosix.cpp b/lldb/source/Host/posix/MainLoopPosix.cpp
index 1715610e0f84f1..a1d697e10a04ed 100644
--- a/lldb/source/Host/posix/MainLoopPosix.cpp
+++ b/lldb/source/Host/posix/MainLoopPosix.cpp
@@ -170,11 +170,23 @@ Status MainLoopPosix::RunImpl::Poll() {
     read_fds.push_back(pfd);
   }
 
+#if defined(_AIX)
+  sigset_t origmask;
+  int timeout;
+
+  timeout = -1;
+  pthread_sigmask(SIG_SETMASK, nullptr, &origmask);
+  int ready = poll(read_fds.data(), read_fds.size(), timeout);
+  pthread_sigmask(SIG_SETMASK, &origmask, nullptr);
+  if (ready == -1 && errno != EINTR)
+    return Status(errno, eErrorTypePOSIX);
+#else
   if (ppoll(read_fds.data(), read_fds.size(),
             ToTimeSpec(loop.GetNextWakeupTime()),
             /*sigmask=*/nullptr) == -1 &&
       errno != EINTR)
     return Status(errno, eErrorTypePOSIX);
+#endif
 
   return Status();
 }
@@ -226,13 +238,13 @@ MainLoopPosix::~MainLoopPosix() {
 #endif
   m_read_fds.erase(m_interrupt_pipe.GetReadFileDescriptor());
   m_interrupt_pipe.Close();
-  assert(m_read_fds.size() == 0); 
+  assert(m_read_fds.size() == 0);
   assert(m_signals.size() == 0);
 }
 
 MainLoopPosix::ReadHandleUP
 MainLoopPosix::RegisterReadObject(const IOObjectSP &object_sp,
-                                 const Callback &callback, Status &error) {
+                                  const Callback &callback, Status &error) {
   if (!object_sp || !object_sp->IsValid()) {
     error = Status::FromErrorString("IO object is not valid.");
     return nullptr;