[LLDB] Don't forcefully initialize the process trace plugin

[walter-erquinigo]

This was causing some process to wrongfully be handled by ProcessTrace.

The only place this was being used is in the intel pt plugin, but it doesn't even build anymore, so I'm sure no one is using it.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Walter Erquinigo (walter-erquinigo)

Changes

• [LLDB][easy] Fix a bug in DummySyntheticFrontEnd
• [LLDB] Don't forcefully initialize the process trace plugin

---

Full diff: https://github.com/llvm/llvm-project/pull/71455.diff

3 Files Affected:

• (modified) lldb/source/API/SystemInitializerFull.cpp (-3)
• (modified) lldb/source/Core/ValueObjectSyntheticFilter.cpp (+1-1)
• (modified) lldb/source/Plugins/Trace/intel-pt/TraceIntelPTBundleLoader.cpp (+5-4)

diff --git a/lldb/source/API/SystemInitializerFull.cpp b/lldb/source/API/SystemInitializerFull.cpp
index 27319debc858288..c48466f25ede81b 100644
--- a/lldb/source/API/SystemInitializerFull.cpp
+++ b/lldb/source/API/SystemInitializerFull.cpp
@@ -68,9 +68,6 @@ llvm::Error SystemInitializerFull::Initialize() {
 #define LLDB_PLUGIN(p) LLDB_PLUGIN_INITIALIZE(p);
 #include "Plugins/Plugins.def"
 
-  // Initialize plug-ins in core LLDB
-  ProcessTrace::Initialize();
-
   // Scan for any system or user LLDB plug-ins
   PluginManager::Initialize();
 
diff --git a/lldb/source/Core/ValueObjectSyntheticFilter.cpp b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
index 59ed780b654f3af..43bc532c4a0410b 100644
--- a/lldb/source/Core/ValueObjectSyntheticFilter.cpp
+++ b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
@@ -41,7 +41,7 @@ class DummySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
     return m_backend.GetIndexOfChildWithName(name);
   }
 
-  bool MightHaveChildren() override { return true; }
+  bool MightHaveChildren() override { return m_backend.MightHaveChildren(); }
 
   bool Update() override { return false; }
 };
diff --git a/lldb/source/Plugins/Trace/intel-pt/TraceIntelPTBundleLoader.cpp b/lldb/source/Plugins/Trace/intel-pt/TraceIntelPTBundleLoader.cpp
index 6bed78fd83f0b70..bd9cca675f2d747 100644
--- a/lldb/source/Plugins/Trace/intel-pt/TraceIntelPTBundleLoader.cpp
+++ b/lldb/source/Plugins/Trace/intel-pt/TraceIntelPTBundleLoader.cpp
@@ -103,10 +103,11 @@ TraceIntelPTBundleLoader::CreateEmptyProcess(lldb::pid_t pid,
   ParsedProcess parsed_process;
   parsed_process.target_sp = target_sp;
 
-  ProcessSP process_sp = target_sp->CreateProcess(
-      /*listener*/ nullptr, "trace",
-      /*crash_file*/ nullptr,
-      /*can_connect*/ false);
+  // This should instead try to directly create an instance of ProcessTrace.
+  // ProcessSP process_sp = target_sp->CreateProcess(
+  //    /*listener*/ nullptr, "trace",
+  //    /*crash_file*/ nullptr,
+  //    /*can_connect*/ false);
 
   process_sp->SetID(static_cast<lldb::pid_t>(pid));
 

[clayborg]

There is no LLDB_PLUGIN_DEFINE() macro in ProcessTrace.cpp, so that is why it was being manually initialized. But this plugin in a problem in that if it's ProcessTrace::CreateInstance(...) is called, it will always return a valid Process plug-in which is bad as it isn't filtering on an architecture, os, or other features of the target.