Add the ability for Script based commands to specify their "repeat command" (#94823)

Among other things, returning an empty string as the repeat command
disables auto-repeat, which can be useful for state-changing commands.

There's one remaining refinement to this setup, which is that for parsed
script commands, it should be possible to change an option value, or add
a new option value that wasn't originally specified, then ask lldb "make
this back into a command string". That would make doing fancy things
with repeat commands easier.

That capability isn't present in the lldb_private side either, however.
So that's for a next iteration.

I haven't added this to the docs on adding commands yet. I wanted to
make sure this was an acceptable approach before I spend the time to do
that.

5 files changed, 66 insertions, 7 deletions

diff --git a/lldb/source/Commands/CommandObjectCommands.cpp b/lldb/source/Commands/CommandObjectCommands.cpp
index f4903e3..c63445b 100644
--- a/lldb/source/Commands/CommandObjectCommands.cpp
+++ b/lldb/source/Commands/CommandObjectCommands.cpp
@@ -1142,6 +1142,15 @@ public:
 
   ScriptedCommandSynchronicity GetSynchronicity() { return m_synchro; }
 
+  std::optional<std::string> GetRepeatCommand(Args &args,
+                                              uint32_t index) override {
+    ScriptInterpreter *scripter = GetDebugger().GetScriptInterpreter();
+    if (!scripter)
+      return std::nullopt;
+
+    return scripter->GetRepeatCommandForScriptedCommand(m_cmd_obj_sp, args);
+  }
+
   llvm::StringRef GetHelp() override {
     if (m_fetched_help_short)
       return CommandObjectRaw::GetHelp();
@@ -1588,7 +1597,9 @@ private:
       options.ForEach(add_element);
       return error;
     }
-    
+
+    size_t GetNumOptions() { return m_num_options; }
+
   private:
     struct EnumValueStorage {
       EnumValueStorage() {
@@ -1827,6 +1838,15 @@ public:
 
   ScriptedCommandSynchronicity GetSynchronicity() { return m_synchro; }
 
+  std::optional<std::string> GetRepeatCommand(Args &args,
+                                              uint32_t index) override {
+    ScriptInterpreter *scripter = GetDebugger().GetScriptInterpreter();
+    if (!scripter)
+      return std::nullopt;
+
+    return scripter->GetRepeatCommandForScriptedCommand(m_cmd_obj_sp, args);
+  }
+
   llvm::StringRef GetHelp() override {
     if (m_fetched_help_short)
       return CommandObjectParsed::GetHelp();
@@ -1857,9 +1877,14 @@ public:
       SetHelpLong(docstring);
     return CommandObjectParsed::GetHelpLong();
   }
-  
-  Options *GetOptions() override { return &m_options; }
 
+  Options *GetOptions() override {
+    // CommandObjectParsed requires that a command with no options return
+    // nullptr.
+    if (m_options.GetNumOptions() == 0)
+      return nullptr;
+    return &m_options;
+  }
 
 protected:
   void DoExecute(Args &args,
diff --git a/lldb/source/Commands/CommandObjectThread.cpp b/lldb/source/Commands/CommandObjectThread.cpp
index 5e64dd2..4398cf3 100644
--- a/lldb/source/Commands/CommandObjectThread.cpp
+++ b/lldb/source/Commands/CommandObjectThread.cpp
@@ -132,7 +132,7 @@ public:
   Options *GetOptions() override { return &m_options; }
 
   std::optional<std::string> GetRepeatCommand(Args &current_args,
-                                              uint32_t idx) override {
+                                              uint32_t index) override {
     llvm::StringRef count_opt("--count");
     llvm::StringRef start_opt("--start");
 
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/SWIGPythonBridge.h b/lldb/source/Plugins/ScriptInterpreter/Python/SWIGPythonBridge.h
index 95eb5a7..3026b61 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/SWIGPythonBridge.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/SWIGPythonBridge.h
@@ -206,6 +206,10 @@ public:
                                   lldb_private::CommandReturnObject &cmd_retobj,
                                   lldb::ExecutionContextRefSP exe_ctx_ref_sp);
 
+  static std::optional<std::string>
+  LLDBSwigPythonGetRepeatCommandForScriptedCommand(PyObject *implementor,
+                                                   std::string &command);
+
   static bool LLDBSwigPythonCallModuleInit(const char *python_module_name,
                                            const char *session_dictionary_name,
                                            lldb::DebuggerSP debugger);
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 70c9f94..70fa6d8 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -2708,6 +2708,33 @@ bool ScriptInterpreterPythonImpl::RunScriptBasedParsedCommand(
   return ret_val;
 }
 
+std::optional<std::string>
+ScriptInterpreterPythonImpl::GetRepeatCommandForScriptedCommand(
+    StructuredData::GenericSP impl_obj_sp, Args &args) {
+  if (!impl_obj_sp || !impl_obj_sp->IsValid())
+    return std::nullopt;
+
+  lldb::DebuggerSP debugger_sp = m_debugger.shared_from_this();
+
+  if (!debugger_sp.get())
+    return std::nullopt;
+
+  std::optional<std::string> ret_val;
+
+  {
+    Locker py_lock(this, Locker::AcquireLock | Locker::NoSTDIN,
+                   Locker::FreeLock);
+
+    StructuredData::ArraySP args_arr_sp(new StructuredData::Array());
+
+    // For scripting commands, we send the command string:
+    std::string command;
+    args.GetQuotedCommandString(command);
+    ret_val = SWIGBridge::LLDBSwigPythonGetRepeatCommandForScriptedCommand(
+        static_cast<PyObject *>(impl_obj_sp->GetValue()), command);
+  }
+  return ret_val;
+}
 
 /// In Python, a special attribute __doc__ contains the docstring for an object
 /// (function, method, class, ...) if any is defined Otherwise, the attribute's
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
index fa23540..c2024ef 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPythonImpl.h
@@ -160,13 +160,16 @@ public:
       lldb_private::CommandReturnObject &cmd_retobj, Status &error,
       const lldb_private::ExecutionContext &exe_ctx) override;
 
-    virtual bool RunScriptBasedParsedCommand(
-      StructuredData::GenericSP impl_obj_sp, Args& args,
+  bool RunScriptBasedParsedCommand(
+      StructuredData::GenericSP impl_obj_sp, Args &args,
       ScriptedCommandSynchronicity synchronicity,
       lldb_private::CommandReturnObject &cmd_retobj, Status &error,
       const lldb_private::ExecutionContext &exe_ctx) override;
 
-  
+  std::optional<std::string>
+  GetRepeatCommandForScriptedCommand(StructuredData::GenericSP impl_obj_sp,
+                                     Args &args) override;
+
   Status GenerateFunction(const char *signature, const StringList &input,
                           bool is_callback) override;