[lldb] Add OS plugin property for reporting all threads

[felipepiovezan]

Currently, an LLDB target option controls whether plugins report all threads. However, it seems natural for this knowledge could come from the plugin itself. To support this, this commits adds a virtual method to the plugin base class, making the Python OS query the target option to preserve existing behavior.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: Felipe de Azevedo Piovezan (felipepiovezan)

Changes

Currently, an LLDB target option controls whether plugins report all threads. However, it seems natural for this knowledge could come from the plugin itself. To support this, this commits adds a virtual method to the plugin base class, making the Python OS query the target option to preserve existing behavior.

---

Full diff: https://github.com/llvm/llvm-project/pull/123145.diff

5 Files Affected:

• (modified) lldb/include/lldb/Target/OperatingSystem.h (+2)
• (modified) lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp (+4)
• (modified) lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.h (+2)
• (modified) lldb/source/Target/Process.cpp (+1-1)
• (modified) lldb/source/Target/TargetProperties.td (+1-1)

diff --git a/lldb/include/lldb/Target/OperatingSystem.h b/lldb/include/lldb/Target/OperatingSystem.h
index ceeddceb0f2c12..128239569790fc 100644
--- a/lldb/include/lldb/Target/OperatingSystem.h
+++ b/lldb/include/lldb/Target/OperatingSystem.h
@@ -61,6 +61,8 @@ class OperatingSystem : public PluginInterface {
 
   virtual bool IsOperatingSystemPluginThread(const lldb::ThreadSP &thread_sp);
 
+  virtual bool DoesPluginReportAllThreads() = 0;
+
 protected:
   // Member variables.
   Process
diff --git a/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp b/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
index 3848a2b1deb97f..7230e590ba03b9 100644
--- a/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
+++ b/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.cpp
@@ -386,4 +386,8 @@ lldb::ThreadSP OperatingSystemPython::CreateThread(lldb::tid_t tid,
   return ThreadSP();
 }
 
+bool OperatingSystemPython::DoesPluginReportAllThreads() {
+  return m_process->GetOSPluginReportsAllThreads();
+}
+
 #endif // #if LLDB_ENABLE_PYTHON
diff --git a/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.h b/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.h
index 90973acde3ebfd..980a544241de4f 100644
--- a/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.h
+++ b/lldb/source/Plugins/OperatingSystem/Python/OperatingSystemPython.h
@@ -60,6 +60,8 @@ class OperatingSystemPython : public lldb_private::OperatingSystem {
   // Method for lazy creation of threads on demand
   lldb::ThreadSP CreateThread(lldb::tid_t tid, lldb::addr_t context) override;
 
+  bool DoesPluginReportAllThreads() override;
+
 protected:
   bool IsValid() const {
     return m_script_object_sp && m_script_object_sp->IsValid();
diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp
index 68485a40a3fcce..c47e728fdf716c 100644
--- a/lldb/source/Target/Process.cpp
+++ b/lldb/source/Target/Process.cpp
@@ -1182,7 +1182,7 @@ void Process::UpdateThreadListIfNeeded() {
           // See if the OS plugin reports all threads.  If it does, then
           // it is safe to clear unseen thread's plans here.  Otherwise we
           // should preserve them in case they show up again:
-          clear_unused_threads = GetOSPluginReportsAllThreads();
+          clear_unused_threads = os->DoesPluginReportAllThreads();
 
           // Turn off dynamic types to ensure we don't run any expressions.
           // Objective-C can run an expression to determine if a SBValue is a
diff --git a/lldb/source/Target/TargetProperties.td b/lldb/source/Target/TargetProperties.td
index bb3b500d5fdfbd..38a345dfd88495 100644
--- a/lldb/source/Target/TargetProperties.td
+++ b/lldb/source/Target/TargetProperties.td
@@ -223,7 +223,7 @@ let Definition = "process_experimental" in {
   def OSPluginReportsAllThreads: Property<"os-plugin-reports-all-threads", "Boolean">,
     Global,
     DefaultTrue,
-    Desc<"Set to False if your OS Plugins doesn't report all threads on each stop.">;
+    Desc<"Set to False if your Python OS Plugin doesn't report all threads on each stop.">;
 }
 
 let Definition = "process" in {

[felipepiovezan]

FWIW I have changed this to True and observed the test failing

[jimingham]

LGTM