[Lldb-commits] [lldb] [lldb] Add 'modify' type watchpoints, make it default (PR #66308)

[Jason Molenda via lldb-commits]

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@@ -211,6 +212,35 @@ bool Watchpoint::CaptureWatchedValue(const ExecutionContext &exe_ctx) {
   return (m_new_value_sp && m_new_value_sp->GetError().Success());
 }
 
+bool Watchpoint::WatchedValueReportable(const ExecutionContext &exe_ctx) {
+  if (!m_watch_modify)
+    return true;
+  if (!m_type.IsValid())
+    return true;
+
+  ConstString watch_name("$__lldb__watch_value");
+  Address watch_address(GetLoadAddress());
+  ValueObjectSP newest_valueobj_sp = ValueObjectMemory::Create(
+      exe_ctx.GetBestExecutionContextScope(), watch_name.GetStringRef(),
+      watch_address, m_type);
+  newest_valueobj_sp = newest_valueobj_sp->CreateConstantValue(watch_name);
+  DataExtractor new_data;
+  DataExtractor old_data;
+  Status error;
+  newest_valueobj_sp->GetData(new_data, error);
+  m_new_value_sp->GetData(old_data, error);
+
----------------
jasonmolenda wrote:

In StopInfoWatchpoint::PerformAction() we decide if we're `m_should_stop` and if so, we call `Watchpoint::CaptureWatchedValue` (one of the things we do before that call is compare the value and decide if we're going to stop or not).  CaptureWatchedValue copies the "new" value into the m_old_value_sp and then creates a new constant value object for m_new_value_sp.  I copied that same way of creating the const ValueObject in this method; it's the method before this one in Watchpoint.cpp.  So the copying of the new value to the previous value is already handled by that code in CaptureWatchedValue.

https://github.com/llvm/llvm-project/pull/66308