Reland "[lldb] Introduce ScriptedFrameProvider for real threads (llvm#161870)" (llvm#170236)

This patch re-lands llvm#161870 with fixes to the previous test failures.

rdar://161834688

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/bindings/python/python-wrapper.swig

@@ -425,6 +425,18 @@ void *lldb_private::python::LLDBSWIGPython_CastPyObjectToSBBreakpoint(PyObject *
   return sb_ptr;
 }
 
+void *lldb_private::python::LLDBSWIGPython_CastPyObjectToSBThread(PyObject * data) {
+  lldb::SBThread *sb_ptr = nullptr;
+
+  int valid_cast =
+      SWIG_ConvertPtr(data, (void **)&sb_ptr, SWIGTYPE_p_lldb__SBThread, 0);
+
+  if (valid_cast == -1)
+    return NULL;
+
+  return sb_ptr;
+}
+
 void *lldb_private::python::LLDBSWIGPython_CastPyObjectToSBFrame(PyObject * data) {
   lldb::SBFrame *sb_ptr = nullptr;
 

lldb/examples/python/templates/scripted_frame_provider.py

@@ -31,7 +31,54 @@ class ScriptedFrameProvider(metaclass=ABCMeta):
         )
     """
 
+    @staticmethod
+    def applies_to_thread(thread):
+        """Determine if this frame provider should be used for a given thread.
+
+        This static method is called before creating an instance of the frame
+        provider to determine if it should be applied to a specific thread.
+        Override this method to provide custom filtering logic.
+
+        Args:
+            thread (lldb.SBThread): The thread to check.
+
+        Returns:
+            bool: True if this frame provider should be used for the thread,
+                False otherwise. The default implementation returns True for
+                all threads.
+
+        Example:
+
+        .. code-block:: python
+
+            @staticmethod
+            def applies_to_thread(thread):
+                # Only apply to thread 1
+                return thread.GetIndexID() == 1
+        """
+        return True
+
+    @staticmethod
     @abstractmethod
+    def get_description():
+        """Get a description of this frame provider.
+
+        This method should return a human-readable string describing what
+        this frame provider does. The description is used for debugging
+        and display purposes.
+
+        Returns:
+            str: A description of the frame provider.
+
+        Example:
+
+        .. code-block:: python
+
+            def get_description(self):
+                return "Crash log frame provider for thread 1"
+        """
+        pass
+
     def __init__(self, input_frames, args):
         """Construct a scripted frame provider.
 

lldb/examples/python/templates/scripted_process.py

@@ -243,6 +243,7 @@ def __init__(self, process, args):
                 key/value pairs used by the scripted thread.
         """
         self.target = None
+        self.arch = None
         self.originating_process = None
         self.process = None
         self.args = None
@@ -264,6 +265,9 @@ def __init__(self, process, args):
             and process.IsValid()
         ):
             self.target = process.target
+            triple = self.target.triple
+            if triple:
+                self.arch = triple.split("-")[0]
             self.originating_process = process
             self.process = self.target.GetProcess()
             self.get_register_info()
@@ -350,17 +354,14 @@ def get_stackframes(self):
     def get_register_info(self):
         if self.register_info is None:
             self.register_info = dict()
-            if "x86_64" in self.originating_process.arch:
+            if "x86_64" in self.arch:
                 self.register_info["sets"] = ["General Purpose Registers"]
                 self.register_info["registers"] = INTEL64_GPR
-            elif (
-                "arm64" in self.originating_process.arch
-                or self.originating_process.arch == "aarch64"
-            ):
+            elif "arm64" in self.arch or self.arch == "aarch64":
                 self.register_info["sets"] = ["General Purpose Registers"]
                 self.register_info["registers"] = ARM64_GPR
             else:
-                raise ValueError("Unknown architecture", self.originating_process.arch)
+                raise ValueError("Unknown architecture", self.arch)
         return self.register_info
 
     @abstractmethod
@@ -403,11 +404,12 @@ def __init__(self, thread, args):
         """Construct a scripted frame.
 
         Args:
-            thread (ScriptedThread): The thread owning this frame.
+            thread (ScriptedThread/lldb.SBThread): The thread owning this frame.
             args (lldb.SBStructuredData): A Dictionary holding arbitrary
                 key/value pairs used by the scripted frame.
         """
         self.target = None
+        self.arch = None
         self.originating_thread = None
         self.thread = None
         self.args = None
@@ -417,15 +419,17 @@ def __init__(self, thread, args):
         self.register_ctx = {}
         self.variables = []
 
-        if (
-            isinstance(thread, ScriptedThread)
-            or isinstance(thread, lldb.SBThread)
-            and thread.IsValid()
+        if isinstance(thread, ScriptedThread) or (
+            isinstance(thread, lldb.SBThread) and thread.IsValid()
         ):
-            self.target = thread.target
             self.process = thread.process
+            self.target = self.process.target
+            triple = self.target.triple
+            if triple:
+                self.arch = triple.split("-")[0]
+            tid = thread.tid if isinstance(thread, ScriptedThread) else thread.id
             self.originating_thread = thread
-            self.thread = self.process.GetThreadByIndexID(thread.tid)
+            self.thread = self.process.GetThreadByIndexID(tid)
             self.get_register_info()
 
     @abstractmethod
@@ -506,7 +510,18 @@ def get_variables(self, filters):
 
     def get_register_info(self):
         if self.register_info is None:
-            self.register_info = self.originating_thread.get_register_info()
+            if isinstance(self.originating_thread, ScriptedThread):
+                self.register_info = self.originating_thread.get_register_info()
+            elif isinstance(self.originating_thread, lldb.SBThread):
+                self.register_info = dict()
+                if "x86_64" in self.arch:
+                    self.register_info["sets"] = ["General Purpose Registers"]
+                    self.register_info["registers"] = INTEL64_GPR
+                elif "arm64" in self.arch or self.arch == "aarch64":
+                    self.register_info["sets"] = ["General Purpose Registers"]
+                    self.register_info["registers"] = ARM64_GPR
+                else:
+                    raise ValueError("Unknown architecture", self.arch)
         return self.register_info
 
     @abstractmethod
@@ -640,12 +655,12 @@ def get_stop_reason(self):
 
             # TODO: Passthrough stop reason from driving process
             if self.driving_thread.GetStopReason() != lldb.eStopReasonNone:
-                if "arm64" in self.originating_process.arch:
+                if "arm64" in self.arch:
                     stop_reason["type"] = lldb.eStopReasonException
                     stop_reason["data"]["desc"] = (
                         self.driving_thread.GetStopDescription(100)
                     )
-                elif self.originating_process.arch == "x86_64":
+                elif self.arch == "x86_64":
                     stop_reason["type"] = lldb.eStopReasonSignal
                     stop_reason["data"]["signal"] = signal.SIGTRAP
                 else:

lldb/include/lldb/API/SBTarget.h

@@ -19,6 +19,7 @@
 #include "lldb/API/SBLaunchInfo.h"
 #include "lldb/API/SBStatisticsOptions.h"
 #include "lldb/API/SBSymbolContextList.h"
+#include "lldb/API/SBThreadCollection.h"
 #include "lldb/API/SBType.h"
 #include "lldb/API/SBValue.h"
 #include "lldb/API/SBWatchpoint.h"
@@ -1003,6 +1004,35 @@ class LLDB_API SBTarget {
 
   lldb::SBMutex GetAPIMutex() const;
 
+  /// Register a scripted frame provider for this target.
+  /// If a scripted frame provider with the same name and same argument
+  /// dictionary is already registered on this target, it will be overwritten.
+  ///
+  /// \param[in] class_name
+  ///     The name of the Python class that implements the frame provider.
+  ///
+  /// \param[in] args_dict
+  ///     A dictionary of arguments to pass to the frame provider class.
+  ///
+  /// \param[out] error
+  ///     An error object indicating success or failure.
+  ///
+  /// \return
+  ///     A unique identifier for the frame provider descriptor that was
+  ///     registered. 0 if the registration failed.
+  uint32_t RegisterScriptedFrameProvider(const char *class_name,
+                                         lldb::SBStructuredData args_dict,
+                                         lldb::SBError &error);
+
+  /// Remove a scripted frame provider from this target by name.
+  ///
+  /// \param[in] provider_id
+  ///     The id of the frame provider class to remove.
+  ///
+  /// \return
+  ///     An error object indicating success or failure.
+  lldb::SBError RemoveScriptedFrameProvider(uint32_t provider_id);
+
 protected:
   friend class SBAddress;
   friend class SBAddressRange;

lldb/include/lldb/API/SBThread.h

@@ -256,6 +256,7 @@ class LLDB_API SBThread {
   friend class SBThreadPlan;
   friend class SBTrace;
 
+  friend class lldb_private::ScriptInterpreter;
   friend class lldb_private::python::SWIGBridge;
 
   SBThread(const lldb::ThreadSP &lldb_object_sp);

lldb/include/lldb/API/SBThreadCollection.h

@@ -46,6 +46,7 @@ class LLDB_API SBThreadCollection {
   void SetOpaque(const lldb::ThreadCollectionSP &threads);
 
 private:
+  friend class SBTarget;
   friend class SBProcess;
   friend class SBThread;
   friend class SBSaveCoreOptions;

lldb/include/lldb/Interpreter/Interfaces/ScriptedFrameProviderInterface.h

@@ -16,11 +16,29 @@
 namespace lldb_private {
 class ScriptedFrameProviderInterface : public ScriptedInterface {
 public:
+  virtual bool AppliesToThread(llvm::StringRef class_name,
+                               lldb::ThreadSP thread_sp) {
+    return true;
+  }
+
   virtual llvm::Expected<StructuredData::GenericSP>
   CreatePluginObject(llvm::StringRef class_name,
                      lldb::StackFrameListSP input_frames,
                      StructuredData::DictionarySP args_sp) = 0;
 
+  /// Get a description string for the frame provider.
+  ///
+  /// This is called by the descriptor to fetch a description from the
+  /// scripted implementation. Implementations should call a static method
+  /// on the scripting class to retrieve the description.
+  ///
+  /// \param class_name The name of the scripting class implementing the
+  /// provider.
+  ///
+  /// \return A string describing what this frame provider does, or an
+  ///         empty string if no description is available.
+  virtual std::string GetDescription(llvm::StringRef class_name) { return {}; }
+
   virtual StructuredData::ObjectSP GetFrameAtIndex(uint32_t index) {
     return {};
   }

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -21,6 +21,7 @@
 #include "lldb/API/SBMemoryRegionInfo.h"
 #include "lldb/API/SBStream.h"
 #include "lldb/API/SBSymbolContext.h"
+#include "lldb/API/SBThread.h"
 #include "lldb/Breakpoint/BreakpointOptions.h"
 #include "lldb/Core/PluginInterface.h"
 #include "lldb/Core/SearchFilter.h"
@@ -580,6 +581,8 @@ class ScriptInterpreter : public PluginInterface {
 
   lldb::StreamSP GetOpaqueTypeFromSBStream(const lldb::SBStream &stream) const;
 
+  lldb::ThreadSP GetOpaqueTypeFromSBThread(const lldb::SBThread &exe_ctx) const;
+
   lldb::StackFrameSP GetOpaqueTypeFromSBFrame(const lldb::SBFrame &frame) const;
 
   SymbolContext

lldb/include/lldb/Target/StackFrame.h

@@ -451,7 +451,7 @@ class StackFrame : public ExecutionContextScope,
   ///   frames are included in this frame index count.
   virtual uint32_t GetFrameIndex() const;
 
-  /// Set this frame's synthetic frame index.
+  /// Set this frame's frame index.
   void SetFrameIndex(uint32_t index) { m_frame_index = index; }
 
   /// Query this frame to find what frame it is in this Thread's
@@ -558,6 +558,7 @@ class StackFrame : public ExecutionContextScope,
 protected:
   friend class BorrowedStackFrame;
   friend class StackFrameList;
+  friend class SyntheticStackFrameList;
 
   void SetSymbolContextScope(SymbolContextScope *symbol_scope);
 

lldb/include/lldb/Target/StackFrameList.h

@@ -26,7 +26,7 @@ class StackFrameList : public std::enable_shared_from_this<StackFrameList> {
   StackFrameList(Thread &thread, const lldb::StackFrameListSP &prev_frames_sp,
                  bool show_inline_frames);
 
-  ~StackFrameList();
+  virtual ~StackFrameList();
 
   /// Get the number of visible frames. Frames may be created if \p can_create
   /// is true. Synthetic (inline) frames expanded from the concrete frame #0
@@ -106,6 +106,7 @@ class StackFrameList : public std::enable_shared_from_this<StackFrameList> {
 
 protected:
   friend class Thread;
+  friend class ScriptedFrameProvider;
   friend class ScriptedThread;
 
   /// Use this API to build a stack frame list (used for scripted threads, for
@@ -211,26 +212,51 @@ class StackFrameList : public std::enable_shared_from_this<StackFrameList> {
   /// Whether or not to show synthetic (inline) frames. Immutable.
   const bool m_show_inlined_frames;
 
+  /// Returns true if fetching frames was interrupted, false otherwise.
+  virtual bool FetchFramesUpTo(uint32_t end_idx,
+                               InterruptionControl allow_interrupt);
+
 private:
   uint32_t SetSelectedFrameNoLock(lldb_private::StackFrame *frame);
   lldb::StackFrameSP
   GetFrameAtIndexNoLock(uint32_t idx,
                         std::shared_lock<std::shared_mutex> &guard);
 
+  /// @{
   /// These two Fetch frames APIs and SynthesizeTailCallFrames are called in
   /// GetFramesUpTo, they are the ones that actually add frames.  They must be
   /// called with the writer end of the list mutex held.
-
-  /// Returns true if fetching frames was interrupted, false otherwise.
-  bool FetchFramesUpTo(uint32_t end_idx, InterruptionControl allow_interrupt);
+  ///
   /// Not currently interruptible so returns void.
+  /// }@
   void FetchOnlyConcreteFramesUpTo(uint32_t end_idx);
   void SynthesizeTailCallFrames(StackFrame &next_frame);
 
   StackFrameList(const StackFrameList &) = delete;
   const StackFrameList &operator=(const StackFrameList &) = delete;
 };
 
+/// A StackFrameList that wraps another StackFrameList and uses a
+/// SyntheticFrameProvider to lazily provide frames from either the provider
+/// or the underlying real stack frame list.
+class SyntheticStackFrameList : public StackFrameList {
+public:
+  SyntheticStackFrameList(Thread &thread, lldb::StackFrameListSP input_frames,
+                          const lldb::StackFrameListSP &prev_frames_sp,
+                          bool show_inline_frames);
+
+protected:
+  /// Override FetchFramesUpTo to lazily return frames from the provider
+  /// or from the actual stack frame list.
+  bool FetchFramesUpTo(uint32_t end_idx,
+                       InterruptionControl allow_interrupt) override;
+
+private:
+  /// The input stack frame list that the provider transforms.
+  /// This could be a real StackFrameList or another SyntheticStackFrameList.
+  lldb::StackFrameListSP m_input_frames;
+};
+
 } // namespace lldb_private
 
 #endif // LLDB_TARGET_STACKFRAMELIST_H