[Lldb-commits] [lldb] [LLDB] Ptrace seize dead processes on Linux (PR #137041)

[David Spickett via lldb-commits]

================
@@ -312,10 +312,27 @@ NativeProcessLinux::Manager::Attach(
   Log *log = GetLog(POSIXLog::Process);
   LLDB_LOG(log, "pid = {0:x}", pid);
 
-  auto tids_or = NativeProcessLinux::Attach(pid);
-  if (!tids_or)
-    return tids_or.takeError();
-  ArrayRef<::pid_t> tids = *tids_or;
+  // This safety check lets us decide if we should
+  // seize or attach.
+  ProcessInstanceInfo process_info;
+  if (!Host::GetProcessInfo(pid, process_info))
+    return llvm::make_error<StringError>("Unable to read process info",
+                                         llvm::inconvertibleErrorCode());
+
+  std::vector<::pid_t> tids;
+  // IsCoreDumping is an optional, so check for value then true/false.
+  if (process_info.IsCoreDumping() && *process_info.IsCoreDumping()) {
+    auto attached_or = NativeProcessLinux::Seize(pid);
+    if (!attached_or)
+      return attached_or.takeError();
+    tids = std::move(*attached_or);
+  } else {
+    auto attached_or = NativeProcessLinux::Attach(pid);
+    if (!attached_or)
+      return attached_or.takeError();
+    tids = std::move(*attached_or);
----------------
DavidSpickett wrote:

Can you refactor this to have only one set of `if (!... ... tids = ` lines? Maybe not because the `auto` would resolve to different things.

Maybe you can do:
```
auto attached_or = is_core_dumping ? NativeProcessLinux::Seize(pid) : NativeProcessLinux::Attach(pid);
```

https://github.com/llvm/llvm-project/pull/137041