Update the lldb driver to support the -O and -S options when passing --repl

[nathawes]

Summary

At the moment when --repl is passed to lldb it silently ignores any commands passed via the options below:

--one-line-before-file <command>
                     Tells the debugger to execute this one-line lldb command before any file provided on the command line has been loaded.
--one-line <command> 
                     Tells the debugger to execute this one-line lldb command after any file provided on the command line has been loaded.  
--source-before-file <file>
                     Tells the debugger to read in and execute the lldb commands in the given file, before any file has been loaded.
--source <file>
                     Tells the debugger to read in and execute the lldb commands in the given file, after any file has been loaded.
-O <value>           Alias for --one-line-before-file
-o <value>           Alias for --one-line
-S <value>           Alias for --source-before-file
-s <value>           Alias for --source

The -O and -S options are quite useful when writing tests for the REPL though, e.g. to change settings prior to entering REPL mode. This patch updates the driver to still respect the commands supplied via -O and -S when passing --repl instead of silently ignoring them. As -s and -o don't really make sense in REPL mode, commands supplied via those options are still ignored, but the driver now emits a warning to make that clear to the user.

[aprantl]

Thanks! LGTM with one tiny change to the test.

lldb/lit/Driver/TestRepl.test

2 ↗

(On Diff #191796)

I think the REPL by default echoes all comments, so this may actually be matching the comment in the input file rather than the warning?

I think this should do the trick:

# CHECK: {{w}}arning: commands specified to run after file load (via -o or -s) are ignored in REPL mode

[nathawes]

lldb/lit/Driver/TestRepl.test

2 ↗

(On Diff #191796)

Good catch! I think this patch actually changes that behavior because the %lldb expansion includes -S path/to/lldb/lit/lit-lldb-init which sets echo-comment-commands false and isn't ignored anymore, but if we ever regress and stop respecting -S this test would still pass...

[nathawes]

Updated the test based on feedback from @aprantl and also to specifically check we don't see the output from the -o and -s commands.

lit/Driver/TestRepl.test

+# RUN: echo ':quit' | %lldb -x --repl -O 'expr 42' -S %S/Inputs/Print2.in -o 'expr 999999' -s %s 2>&1 | FileCheck %s
+# CHECK: {{w}}arning: commands specified to run after file load (via -o or -s) are ignored in REPL mode
+# CHECK: (int) $0 = 42
+# CHECK: (int) $1 = 2
+# CHECK-NOT: 999999
+
+expr 999999

tools/driver/Driver.cpp

#endif
 
   // Now we handle options we got from the command line
   SBStream commands_stream;
 
   // First source in the commands specified to be run before the file arguments
   // are processed.
   WriteCommandsForSourcing(eCommandPlacementBeforeFile, commands_stream);
 
+  // If we're not in --repl mode, add the commands to process the file
+  // arguments, and the commands specified to run afterwards.
+  if (!m_option_data.m_repl) {
     const size_t num_args = m_option_data.m_args.size();
     if (num_args > 0) {
       char arch_name[64];
       if (lldb::SBDebugger::GetDefaultArchitecture(arch_name, sizeof(arch_name)))
         commands_stream.Printf("target create --arch=%s %s", arch_name,
                                EscapeString(m_option_data.m_args[0]).c_str());
       else
         commands_stream.Printf("target create %s",
                                EscapeString(m_option_data.m_args[0]).c_str());
 
       if (!m_option_data.m_core_file.empty()) {
         commands_stream.Printf(" --core %s",
                                EscapeString(m_option_data.m_core_file).c_str());
       }
       commands_stream.Printf("\n");
 
       if (num_args > 1) {
         commands_stream.Printf("settings set -- target.run-args ");
         for (size_t arg_idx = 1; arg_idx < num_args; ++arg_idx)
           commands_stream.Printf(
               " %s", EscapeString(m_option_data.m_args[arg_idx]).c_str());
         commands_stream.Printf("\n");
       }
     } else if (!m_option_data.m_core_file.empty()) {
       commands_stream.Printf("target create --core %s\n",
                              EscapeString(m_option_data.m_core_file).c_str());
     } else if (!m_option_data.m_process_name.empty()) {
       commands_stream.Printf("process attach --name %s",
                              EscapeString(m_option_data.m_process_name).c_str());
 
       if (m_option_data.m_wait_for)
         commands_stream.Printf(" --waitfor");
 
       commands_stream.Printf("\n");
 
     } else if (LLDB_INVALID_PROCESS_ID != m_option_data.m_process_pid) {
       commands_stream.Printf("process attach --pid %" PRIu64 "\n",
                              m_option_data.m_process_pid);
     }
 
     WriteCommandsForSourcing(eCommandPlacementAfterFile, commands_stream);
+  } else if (!m_option_data.m_after_file_commands.empty()) {
+    // We're in repl mode and after-file-load commands were specified.
+    WithColor::warning() << "commands specified to run after file load (via -o "
+      "or -s) are ignored in REPL mode.\n";
+  }
 
   if (GetDebugMode()) {
     result.PutError(m_debugger.GetErrorFileHandle());
     result.PutOutput(m_debugger.GetOutputFileHandle());
   }
 
   bool handle_events = true;
   bool spawn_thread = false;
 
-  if (m_option_data.m_repl) {
-    const char *repl_options = nullptr;
-    if (!m_option_data.m_repl_options.empty())
-      repl_options = m_option_data.m_repl_options.c_str();
-    SBError error(m_debugger.RunREPL(m_option_data.m_repl_lang, repl_options));
-    if (error.Fail()) {
-      const char *error_cstr = error.GetCString();
-      if ((error_cstr != nullptr) && (error_cstr[0] != 0))
-        WithColor::error() << error_cstr << '\n';
-      else
-        WithColor::error() << error.GetError() << '\n';
-    }
-  } else {
-    // Check if we have any data in the commands stream, and if so, save it to a
-    // temp file
-    // so we can then run the command interpreter using the file contents.
-    const char *commands_data = commands_stream.GetData();
-    const size_t commands_size = commands_stream.GetSize();
 
-    // The command file might have requested that we quit, this variable will
-    // track that.
-    bool quit_requested = false;
-    bool stopped_for_crash = false;
-    if ((commands_data != nullptr) && (commands_size != 0u)) {
-      int initial_commands_fds[2];
-      bool success = true;
-      FILE *commands_file = PrepareCommandsForSourcing(
-          commands_data, commands_size, initial_commands_fds);
-      if (commands_file != nullptr) {
-        m_debugger.SetInputFileHandle(commands_file, true);
 
-        // Set the debugger into Sync mode when running the command file.
-        // Otherwise command files
-        // that run the target won't run in a sensible way.
-        bool old_async = m_debugger.GetAsync();
-        m_debugger.SetAsync(false);
-        int num_errors;
 
-        SBCommandInterpreterRunOptions options;
-        options.SetStopOnError(true);
-        if (m_option_data.m_batch)
-          options.SetStopOnCrash(true);
 
-        m_debugger.RunCommandInterpreter(handle_events, spawn_thread, options,
-                                         num_errors, quit_requested,
-                                         stopped_for_crash);
 
-        if (m_option_data.m_batch && stopped_for_crash &&
-            !m_option_data.m_after_crash_commands.empty()) {
-          int crash_command_fds[2];
-          SBStream crash_commands_stream;
-          WriteCommandsForSourcing(eCommandPlacementAfterCrash,
-                                   crash_commands_stream);
-          const char *crash_commands_data = crash_commands_stream.GetData();
-          const size_t crash_commands_size = crash_commands_stream.GetSize();
-          commands_file = PrepareCommandsForSourcing(
-              crash_commands_data, crash_commands_size, crash_command_fds);
-          if (commands_file != nullptr) {
-            bool local_quit_requested;
-            bool local_stopped_for_crash;
-            m_debugger.SetInputFileHandle(commands_file, true);
 
-            m_debugger.RunCommandInterpreter(
-                handle_events, spawn_thread, options, num_errors,
-                local_quit_requested, local_stopped_for_crash);
-            if (local_quit_requested)
-              quit_requested = true;
-          }
-        }
-        m_debugger.SetAsync(old_async);
-      } else
-        success = false;
 
-      // Close any pipes that we still have ownership of
-      CleanupAfterCommandSourcing(initial_commands_fds);
 
-      // Something went wrong with command pipe
-      if (!success) {
-        exit(1);
-      }
-    }
 
-    // Now set the input file handle to STDIN and run the command
-    // interpreter again in interactive mode and let the debugger
-    // take ownership of stdin
+  // interpreter again in interactive mode or repl mode and let the debugger
 
-    bool go_interactive = true;
-    if (quit_requested)
-      go_interactive = false;
-    else if (m_option_data.m_batch && !stopped_for_crash)
-      go_interactive = false;
 
-    if (go_interactive) {
-      m_debugger.SetInputFileHandle(stdin, true);
+
+    if (m_option_data.m_repl) {
+      const char *repl_options = nullptr;
+      if (!m_option_data.m_repl_options.empty())
+        repl_options = m_option_data.m_repl_options.c_str();
+      SBError error(m_debugger.RunREPL(m_option_data.m_repl_lang, repl_options));
+      if (error.Fail()) {
+        const char *error_cstr = error.GetCString();
+        if ((error_cstr != nullptr) && (error_cstr[0] != 0))
+          WithColor::error() << error_cstr << '\n';
+        else
+          WithColor::error() << error.GetError() << '\n';
+      }
+    } else {
       m_debugger.RunCommandInterpreter(handle_events, spawn_thread);
     }
   }
 
   reset_stdin_termios();
   fclose(stdin);
 
   int exit_code = sb_interpreter.GetQuitStatus();
EXAMPLES:
   Passing --repl starts lldb in REPL mode.
 
     lldb -r
 
   Passing --core causes lldb to debug the core file.
 
     lldb -c /path/to/core
 
-  Command options can be combined with either mode and cause lldb to run the
+  Command options can be combined with these modes and cause lldb to run the
   specified commands before or after events, like loading the file or crashing,
   in the order provided on the command line.
 
     lldb -O 'settings set stop-disassembly-count 20' -o 'run' -o 'bt'
     lldb -S /source/before/file -s /source/after/file
     lldb -K /source/before/crash -k /source/after/crash
+
+  Note: In REPL mode no file is loaded, so commands specified to run after
+  loading the file (via -o or -s) will be ignored.
   )___";
   llvm::outs() << examples;
 }
 
 llvm::Optional<int> InitializeReproducer(opt::InputArgList &input_args) {
   if (auto *replay_path = input_args.getLastArg(OPT_replay)) {
     if (const char *error = SBReproducer::Replay(replay_path->getValue())) {
       WithColor::error() << "reproducer replay failed: " << error << '\n';