[Lldb-commits] [lldb] [lldb][AIX] Implement read/write handling for GPR and SPR registers (PR #193205)

[David Spickett via lldb-commits]

================
@@ -279,13 +282,98 @@ llvm::Error NativeProcessAIX::Detach(lldb::tid_t tid) {
   return PtraceWrapper(PT_DETACH, tid).takeError();
 }
 
+template <typename GPR_T, typename PTSPRS_T>
+int GetSPRs(int req, lldb::tid_t tid, GPR_T *gpr) {
+  PTSPRS_T sprs;
+
+  int ret = ptrace64(req, tid, reinterpret_cast<long long>(&sprs), 0, 0);
+
+  if (ret != -1) {
+    gpr->cr = sprs.pt_cr;
+    gpr->msr = sprs.pt_msr;
+    gpr->xer = sprs.pt_xer;
+    gpr->lr = sprs.pt_lr;
+    gpr->ctr = sprs.pt_ctr;
+    gpr->pc = sprs.pt_iar;
+  }
+  return ret;
+}
+
+template <typename GPR_T, typename PTSPRS_T>
+int SetSPRs(int req, lldb::tid_t tid, GPR_T *gpr) {
+  PTSPRS_T sprs;
+
+  sprs.pt_cr = gpr->cr;
+  sprs.pt_msr = gpr->msr;
+  sprs.pt_xer = gpr->xer;
+  sprs.pt_lr = gpr->lr;
+  sprs.pt_ctr = gpr->ctr;
+  sprs.pt_iar = gpr->pc;
+
+  return ptrace64(req, tid, reinterpret_cast<long long>(&sprs), 0, 0);
+}
+
 llvm::Expected<int> NativeProcessAIX::PtraceWrapper(int req, lldb::pid_t pid,
                                                     void *addr, void *data,
                                                     size_t data_size) {
-  int ret;
-
+  int ret = 0;
   Log *log = GetLog(POSIXLog::Ptrace);
+  // PTT_* requests require a thread ID (TID).
+  // Each entry under /proc/<pid>/lwp/ represents a thread,
+  // and the directory name corresponds to its thread ID (TID).
+  // A process may contain multiple threads.
+  // TODO: With multi-threading support, iterate over all entries to enumerate
+  // available TIDs and retrieve the target debugging thread ID.
+  llvm::SmallString<128> proc_lwp_dir;
+  llvm::sys::path::append(proc_lwp_dir, "/proc/", std::to_string(pid), "/lwp/");
+
+  lldb::tid_t tid = 0;
+  std::error_code ec;
+  bool result;
+  if (!llvm::sys::fs::is_directory(proc_lwp_dir, result) && result) {
----------------
DavidSpickett wrote:

Sorry I'm reading this incorrectly. Result tells you whether it is a dir or not, and the return type is whether the operation succeeded or not.

So "not return value" means "if the return value was not some error".

https://github.com/llvm/llvm-project/pull/193205