Add AllowRepeats to SBCommandInterpreterRunOptions. (#94786)

This is useful if you have a transcript of a user session and want to
rerun those commands with RunCommandInterpreter. The same functionality
is also useful in testing.

I'm adding it primarily for the second reason. In a subsequent patch,
I'm adding the ability to Python based commands to provide their
"auto-repeat" command. Among other things, that will allow potentially
state destroying user commands to prevent auto-repeat. Testing this with
Shell or pexpect tests is not nearly as accurate or convenient as using
RunCommandInterpreter, but to use that I need to allow auto-repeat.

I think for consistency's sake, having interactive sessions always do
auto-repeats is the right choice, though that's a lightly held
opinion...

Author: jimingham

lldb/bindings/interface/SBCommandInterpreterRunOptionsDocstrings.i

@@ -10,5 +10,8 @@ A default SBCommandInterpreterRunOptions object has:
 * PrintResults:   true
 * PrintErrors:    true
 * AddToHistory:   true
+* AllowRepeats    false
 
+Interactive debug sessions always allow repeats, the AllowRepeats
+run option only affects non-interactive sessions.
 ") lldb::SBCommandInterpreterRunOptions;

lldb/include/lldb/API/SBCommandInterpreterRunOptions.h

@@ -72,6 +72,14 @@ class LLDB_API SBCommandInterpreterRunOptions {
 
   void SetSpawnThread(bool);
 
+  bool GetAllowRepeats() const;
+
+  /// By default, RunCommandInterpreter will discard repeats if the
+  /// IOHandler being used is not interactive.  Setting AllowRepeats to true
+  /// will override this behavior and always process empty lines in the input
+  /// as a repeat command.
+  void SetAllowRepeats(bool);
+
 private:
   lldb_private::CommandInterpreterRunOptions *get() const;
 

lldb/include/lldb/Interpreter/CommandInterpreter.h

@@ -93,15 +93,20 @@ class CommandInterpreterRunOptions {
   /// \param[in] add_to_history
   ///    If \b true add the commands to the command history. If \b false, don't
   ///    add them.
+  /// \param[in] handle_repeats
+  ///    If \b true then treat empty lines as repeat commands even if the
+  ///    interpreter is non-interactive.
   CommandInterpreterRunOptions(LazyBool stop_on_continue,
                                LazyBool stop_on_error, LazyBool stop_on_crash,
                                LazyBool echo_commands, LazyBool echo_comments,
                                LazyBool print_results, LazyBool print_errors,
-                               LazyBool add_to_history)
+                               LazyBool add_to_history,
+                               LazyBool handle_repeats)
       : m_stop_on_continue(stop_on_continue), m_stop_on_error(stop_on_error),
         m_stop_on_crash(stop_on_crash), m_echo_commands(echo_commands),
         m_echo_comment_commands(echo_comments), m_print_results(print_results),
-        m_print_errors(print_errors), m_add_to_history(add_to_history) {}
+        m_print_errors(print_errors), m_add_to_history(add_to_history),
+        m_allow_repeats(handle_repeats) {}
 
   CommandInterpreterRunOptions() = default;
 
@@ -183,6 +188,12 @@ class CommandInterpreterRunOptions {
     m_spawn_thread = spawn_thread ? eLazyBoolYes : eLazyBoolNo;
   }
 
+  bool GetAllowRepeats() const { return DefaultToNo(m_allow_repeats); }
+
+  void SetAllowRepeats(bool allow_repeats) {
+    m_allow_repeats = allow_repeats ? eLazyBoolYes : eLazyBoolNo;
+  }
+
   LazyBool m_stop_on_continue = eLazyBoolCalculate;
   LazyBool m_stop_on_error = eLazyBoolCalculate;
   LazyBool m_stop_on_crash = eLazyBoolCalculate;
@@ -193,6 +204,7 @@ class CommandInterpreterRunOptions {
   LazyBool m_add_to_history = eLazyBoolCalculate;
   LazyBool m_auto_handle_events;
   LazyBool m_spawn_thread;
+  LazyBool m_allow_repeats = eLazyBoolCalculate;
 
 private:
   static bool DefaultToYes(LazyBool flag) {

lldb/source/API/SBCommandInterpreterRunOptions.cpp

@@ -164,6 +164,18 @@ void SBCommandInterpreterRunOptions::SetSpawnThread(bool spawn_thread) {
   m_opaque_up->SetSpawnThread(spawn_thread);
 }
 
+bool SBCommandInterpreterRunOptions::GetAllowRepeats() const {
+  LLDB_INSTRUMENT_VA(this);
+
+  return m_opaque_up->GetAllowRepeats();
+}
+
+void SBCommandInterpreterRunOptions::SetAllowRepeats(bool allow_repeats) {
+  LLDB_INSTRUMENT_VA(this, allow_repeats);
+
+  m_opaque_up->SetAllowRepeats(allow_repeats);
+}
+
 lldb_private::CommandInterpreterRunOptions *
 SBCommandInterpreterRunOptions::get() const {
   return m_opaque_up.get();

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -2707,7 +2707,8 @@ enum {
   eHandleCommandFlagEchoCommentCommand = (1u << 3),
   eHandleCommandFlagPrintResult = (1u << 4),
   eHandleCommandFlagPrintErrors = (1u << 5),
-  eHandleCommandFlagStopOnCrash = (1u << 6)
+  eHandleCommandFlagStopOnCrash = (1u << 6),
+  eHandleCommandFlagAllowRepeats = (1u << 7)
 };
 
 void CommandInterpreter::HandleCommandsFromFile(
@@ -3129,14 +3130,19 @@ void CommandInterpreter::IOHandlerInputComplete(IOHandler &io_handler,
       return;
 
   const bool is_interactive = io_handler.GetIsInteractive();
-  if (!is_interactive) {
+  const bool allow_repeats =
+      io_handler.GetFlags().Test(eHandleCommandFlagAllowRepeats);
+
+  if (!is_interactive && !allow_repeats) {
     // When we are not interactive, don't execute blank lines. This will happen
     // sourcing a commands file. We don't want blank lines to repeat the
     // previous command and cause any errors to occur (like redefining an
     // alias, get an error and stop parsing the commands file).
+    // But obey the AllowRepeats flag if the user has set it.
     if (line.empty())
       return;
-
+  }
+  if (!is_interactive) {
     // When using a non-interactive file handle (like when sourcing commands
     // from a file) we need to echo the command out so we don't just see the
     // command output and no command...
@@ -3388,6 +3394,8 @@ CommandInterpreter::GetIOHandler(bool force_create,
         flags |= eHandleCommandFlagPrintResult;
       if (options->m_print_errors != eLazyBoolNo)
         flags |= eHandleCommandFlagPrintErrors;
+      if (options->m_allow_repeats == eLazyBoolYes)
+        flags |= eHandleCommandFlagAllowRepeats;
     } else {
       flags = eHandleCommandFlagEchoCommand | eHandleCommandFlagPrintResult |
               eHandleCommandFlagPrintErrors;

lldb/test/API/python_api/interpreter/TestRunCommandInterpreterAPI.py

@@ -47,28 +47,66 @@ def setUp(self):
         TestBase.setUp(self)
 
         self.stdin_path = self.getBuildArtifact("stdin.txt")
+        self.stdout_path = self.getBuildArtifact("stdout.txt")
+
+    def run_commands_string(
+        self, command_string, options=lldb.SBCommandInterpreterRunOptions()
+    ):
+        """Run the commands in command_string through RunCommandInterpreter.
+        Returns (n_errors, quit_requested, has_crashed, result_string)."""
 
         with open(self.stdin_path, "w") as input_handle:
-            input_handle.write("nonexistingcommand\nquit")
+            input_handle.write(command_string)
 
-        self.dbg.SetInputFile(open(self.stdin_path, "r"))
+        n_errors = 0
+        quit_requested = False
+        has_crashed = False
 
-        # No need to track the output
-        devnull = open(os.devnull, "w")
-        self.dbg.SetOutputFile(devnull)
-        self.dbg.SetErrorFile(devnull)
+        with open(self.stdin_path, "r") as in_fileH, open(
+            self.stdout_path, "w"
+        ) as out_fileH:
+            self.dbg.SetInputFile(in_fileH)
+
+            self.dbg.SetOutputFile(out_fileH)
+            self.dbg.SetErrorFile(out_fileH)
+
+            n_errors, quit_requested, has_crashed = self.dbg.RunCommandInterpreter(
+                True, False, options, 0, False, False
+            )
+
+        result_string = None
+        with open(self.stdout_path, "r") as out_fileH:
+            result_string = out_fileH.read()
+
+        return (n_errors, quit_requested, has_crashed, result_string)
 
     def test_run_session_with_error_and_quit(self):
         """Run non-existing and quit command returns appropriate values"""
 
-        n_errors, quit_requested, has_crashed = self.dbg.RunCommandInterpreter(
-            True, False, lldb.SBCommandInterpreterRunOptions(), 0, False, False
+        n_errors, quit_requested, has_crashed, _ = self.run_commands_string(
+            "nonexistingcommand\nquit\n"
         )
-
         self.assertGreater(n_errors, 0)
         self.assertTrue(quit_requested)
         self.assertFalse(has_crashed)
 
+    def test_allow_repeat(self):
+        """Try auto-repeat of process launch - the command will fail and
+        the auto-repeat will fail because of no auto-repeat."""
+        options = lldb.SBCommandInterpreterRunOptions()
+        options.SetEchoCommands(False)
+        options.SetAllowRepeats(True)
+
+        n_errors, quit_requested, has_crashed, result_str = self.run_commands_string(
+            "process launch\n\n", options
+        )
+        self.assertEqual(n_errors, 2)
+        self.assertFalse(quit_requested)
+        self.assertFalse(has_crashed)
+
+        self.assertIn("invalid target", result_str)
+        self.assertIn("No auto repeat", result_str)
+
 
 class SBCommandInterpreterRunOptionsCase(TestBase):
     NO_DEBUG_INFO_TESTCASE = True
@@ -86,6 +124,7 @@ def test_command_interpreter_run_options(self):
         self.assertTrue(opts.GetPrintResults())
         self.assertTrue(opts.GetPrintErrors())
         self.assertTrue(opts.GetAddToHistory())
+        self.assertFalse(opts.GetAllowRepeats())
 
         # Invert values
         opts.SetStopOnContinue(not opts.GetStopOnContinue())
@@ -95,6 +134,7 @@ def test_command_interpreter_run_options(self):
         opts.SetPrintResults(not opts.GetPrintResults())
         opts.SetPrintErrors(not opts.GetPrintErrors())
         opts.SetAddToHistory(not opts.GetAddToHistory())
+        opts.SetAllowRepeats(not opts.GetAllowRepeats())
 
         # Check the value changed
         self.assertTrue(opts.GetStopOnContinue())
@@ -104,3 +144,4 @@ def test_command_interpreter_run_options(self):
         self.assertFalse(opts.GetPrintResults())
         self.assertFalse(opts.GetPrintErrors())
         self.assertFalse(opts.GetAddToHistory())
+        self.assertTrue(opts.GetAllowRepeats())