[Lldb-commits] [lldb] [lldb] [Process/FreeBSDKernel] List threads in correct order (PR #178306)

[Alex Langford via lldb-commits]

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@@ -174,29 +174,39 @@ bool ProcessFreeBSDKernel::DoUpdateThreadList(ThreadList &old_thread_list,
         ReadSignedIntegerFromMemory(FindSymbol("dumptid"), 4, -1, error);
     lldb::addr_t dumppcb = FindSymbol("dumppcb");
 
-    // stoppcbs is an array of PCBs on all CPUs
-    // each element is of size pcb_size
+    // stoppcbs is an array of PCBs on all CPUs.
+    // Each element is of size pcb_size.
     int32_t pcbsize =
         ReadSignedIntegerFromMemory(FindSymbol("pcb_size"), 4, -1, error);
     lldb::addr_t stoppcbs = FindSymbol("stoppcbs");
 
     // from FreeBSD sys/param.h
     constexpr size_t fbsd_maxcomlen = 19;
 
-    // iterate through a linked list of all processes
-    // allproc is a pointer to the first list element, p_list field
-    // (found at offset_p_list) specifies the next element
+    // Iterate through a linked list of all processes. New processes are added
+    // to the head of this list. Which means that earlier PIDs are actually at
+    // the end of the list, so we have to walk it backwards. First collect all
+    // the processes in the list order.
+    std::vector<lldb::addr_t> process_addrs;
     for (lldb::addr_t proc =
              ReadPointerFromMemory(FindSymbol("allproc"), error);
          proc != 0 && proc != LLDB_INVALID_ADDRESS;
          proc = ReadPointerFromMemory(proc + offset_p_list, error)) {
+      process_addrs.push_back(proc);
+    }
+
+    // Processes are in the linked list in descending PID order, so we must walk
+    // them in reverse to get ascending PID order.
+    for (auto proc_it = process_addrs.rbegin(); proc_it != process_addrs.rend();
+         ++proc_it) {
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bulbazord wrote:

Are the curly braces balanced? I see you adding an opening brace but I don't see an added closing brace or a removed opening brace.

https://github.com/llvm/llvm-project/pull/178306