[lldb/interpreter] Add ability to save lldb session to a file

This patch introduce a new feature that allows the users to save their
debugging session's transcript (commands + outputs) to a file.

It differs from the reproducers since it doesn't require to capture a
session preemptively and replay the reproducer file in lldb.
The user can choose the save its session manually using the session save
command or automatically by setting the interpreter.save-session-on-quit
on their init file.

To do so, the patch adds a Stream object to the CommandInterpreter that
will hold the input command from the IOHandler and the CommandReturnObject
output and error. This way, that stream object accumulates passively all
the interactions throughout the session and will save them to disk on demand.

The user can specify a file path where the session's transcript will be
saved. However, it is optional, and when it is not provided, lldb will
create a temporary file name according to the session date and time.

rdar://63347792

Differential Revision: https://reviews.llvm.org/D82155

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>

1 files changed, 67 insertions, 1 deletions

diff --git a/lldb/source/Interpreter/CommandInterpreter.cpp b/lldb/source/Interpreter/CommandInterpreter.cpp
index baceeac..1eddf0b 100644
--- a/lldb/source/Interpreter/CommandInterpreter.cpp
+++ b/lldb/source/Interpreter/CommandInterpreter.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include <limits>
 #include <memory>
 #include <stdlib.h>
 #include <string>
@@ -31,6 +32,7 @@
 #include "Commands/CommandObjectQuit.h"
 #include "Commands/CommandObjectRegister.h"
 #include "Commands/CommandObjectReproducer.h"
+#include "Commands/CommandObjectSession.h"
 #include "Commands/CommandObjectSettings.h"
 #include "Commands/CommandObjectSource.h"
 #include "Commands/CommandObjectStats.h"
@@ -52,6 +54,8 @@
 #if LLDB_ENABLE_LIBEDIT
 #include "lldb/Host/Editline.h"
 #endif
+#include "lldb/Host/File.h"
+#include "lldb/Host/FileCache.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostInfo.h"
 
@@ -74,6 +78,7 @@
 #include "llvm/Support/FormatAdapters.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/ScopedPrinter.h"
 
 using namespace lldb;
 using namespace lldb_private;
@@ -116,7 +121,7 @@ CommandInterpreter::CommandInterpreter(Debugger &debugger,
       m_skip_lldbinit_files(false), m_skip_app_init_files(false),
       m_command_io_handler_sp(), m_comment_char('#'),
       m_batch_command_mode(false), m_truncation_warning(eNoTruncation),
-      m_command_source_depth(0), m_result() {
+      m_command_source_depth(0), m_result(), m_transcript_stream() {
   SetEventName(eBroadcastBitThreadShouldExit, "thread-should-exit");
   SetEventName(eBroadcastBitResetPrompt, "reset-prompt");
   SetEventName(eBroadcastBitQuitCommandReceived, "quit");
@@ -142,6 +147,17 @@ void CommandInterpreter::SetPromptOnQuit(bool enable) {
   m_collection_sp->SetPropertyAtIndexAsBoolean(nullptr, idx, enable);
 }
 
+bool CommandInterpreter::GetSaveSessionOnQuit() const {
+  const uint32_t idx = ePropertySaveSessionOnQuit;
+  return m_collection_sp->GetPropertyAtIndexAsBoolean(
+      nullptr, idx, g_interpreter_properties[idx].default_uint_value != 0);
+}
+
+void CommandInterpreter::SetSaveSessionOnQuit(bool enable) {
+  const uint32_t idx = ePropertySaveSessionOnQuit;
+  m_collection_sp->SetPropertyAtIndexAsBoolean(nullptr, idx, enable);
+}
+
 bool CommandInterpreter::GetEchoCommands() const {
   const uint32_t idx = ePropertyEchoCommands;
   return m_collection_sp->GetPropertyAtIndexAsBoolean(
@@ -493,6 +509,7 @@ void CommandInterpreter::LoadCommandDictionary() {
       CommandObjectSP(new CommandObjectReproducer(*this));
   m_command_dict["script"] =
       CommandObjectSP(new CommandObjectScript(*this, script_language));
+  m_command_dict["session"] = std::make_shared<CommandObjectSession>(*this);
   m_command_dict["settings"] =
       CommandObjectSP(new CommandObjectMultiwordSettings(*this));
   m_command_dict["source"] =
@@ -1667,6 +1684,8 @@ bool CommandInterpreter::HandleCommand(const char *command_line,
   else
     add_to_history = (lazy_add_to_history == eLazyBoolYes);
 
+  m_transcript_stream << "(lldb) " << command_line << '\n';
+
   bool empty_command = false;
   bool comment_command = false;
   if (command_string.empty())
@@ -1799,6 +1818,9 @@ bool CommandInterpreter::HandleCommand(const char *command_line,
   LLDB_LOGF(log, "HandleCommand, command %s",
             (result.Succeeded() ? "succeeded" : "did not succeed"));
 
+  m_transcript_stream << result.GetOutputData();
+  m_transcript_stream << result.GetErrorData();
+
   return result.Succeeded();
 }
 
@@ -2877,6 +2899,50 @@ bool CommandInterpreter::IOHandlerInterrupt(IOHandler &io_handler) {
   return false;
 }
 
+bool CommandInterpreter::SaveTranscript(
+    CommandReturnObject &result, llvm::Optional<std::string> output_file) {
+  if (output_file == llvm::None || output_file->empty()) {
+    std::string now = llvm::to_string(std::chrono::system_clock::now());
+    std::replace(now.begin(), now.end(), ' ', '_');
+    const std::string file_name = "lldb_session_" + now + ".log";
+    FileSpec tmp = HostInfo::GetGlobalTempDir();
+    tmp.AppendPathComponent(file_name);
+    output_file = tmp.GetPath();
+  }
+
+  auto error_out = [&](llvm::StringRef error_message, std::string description) {
+    LLDB_LOG(GetLogIfAllCategoriesSet(LIBLLDB_LOG_COMMANDS), "{0} ({1}:{2})",
+             error_message, output_file, description);
+    result.AppendErrorWithFormatv(
+        "Failed to save session's transcripts to {0}!", *output_file);
+    return false;
+  };
+
+  File::OpenOptions flags = File::eOpenOptionWrite |
+                            File::eOpenOptionCanCreate |
+                            File::eOpenOptionTruncate;
+
+  auto opened_file = FileSystem::Instance().Open(FileSpec(*output_file), flags);
+
+  if (!opened_file)
+    return error_out("Unable to create file",
+                     llvm::toString(opened_file.takeError()));
+
+  FileUP file = std::move(opened_file.get());
+
+  size_t byte_size = m_transcript_stream.GetSize();
+
+  Status error = file->Write(m_transcript_stream.GetData(), byte_size);
+
+  if (error.Fail() || byte_size != m_transcript_stream.GetSize())
+    return error_out("Unable to write to destination file",
+                     "Bytes written do not match transcript size.");
+
+  result.AppendMessageWithFormat("Session's transcripts saved to %s\n", output_file->c_str());
+
+  return true;
+}
+
 void CommandInterpreter::GetLLDBCommandsFromIOHandler(
     const char *prompt, IOHandlerDelegate &delegate, void *baton) {
   Debugger &debugger = GetDebugger();