[Lldb-commits] [lldb] [lldb] Guard SBFrame/SBThread methods against running processes (PR #152020)

[via lldb-commits]

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@@ -233,6 +233,10 @@ class LLDB_API SBFrame {
 
   void SetFrameSP(const lldb::StackFrameSP &lldb_object_sp);
 
+  /// Return an SBValue with an error message warning that the process is not
+  /// currently stopped.
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jimingham wrote:

At the SB API level, if you are getting the ExecutionContext from an ExecutionContextRef represented by a Target, Process, Thread or Frame you should also hold the API mutex.  There are some cases where we don't actually require a process.  For instance SBTarget::CreateValueFromAddress can work on either a live process that's stopped or to look at static data on a non-running target.  But those seem like they are in the minority, and in that case, for instance, you could easily do:

if (!process || stop_locker.IsLocked())

so that wouldn't be particularly awkward.  

I can't think of a good reason why you would want to drop the API lock before the stop lock or vice versa.  There's the one place where Felipe swaps the stop_locker originally set for another, so long as this doesn't make that particularly awkward, this seems doable.

https://github.com/llvm/llvm-project/pull/152020