CLIDebugger.cpp   [plain text]

//===-- CLIDebugger.cpp - Command Line Interface to the Debugger ----------===//
//                     The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file contains the main implementation of the Command Line Interface to
// the debugger.

#include "CLIDebugger.h"
#include "CLICommand.h"
#include "llvm/Debugger/SourceFile.h"
#include "llvm/ADT/StringExtras.h"
#include <iostream>
using namespace llvm;

/// CLIDebugger constructor - This initializes the debugger to its default
/// state, and initializes the command table.
  : TheProgramInfo(0), TheRuntimeInfo(0), Prompt("(llvm-db) "), ListSize(10) {
  // Initialize instance variables
  CurrentFile = 0;
  LineListedStart = 1;
  LineListedEnd = 1;
  LastCurrentFrame = 0;
  CurrentLanguage = 0;

  CLICommand *C;
  // Program startup and shutdown options
  addCommand("file", new BuiltinCLICommand(
    "Use specified file as the program to be debugged",
    "The debugger looks in the current directory and the program $PATH for the"
    " specified LLVM program.  It then unloads the currently loaded program and"
    " loads the specified program.\n",

  addCommand("create", new BuiltinCLICommand(
    "Start the program, halting its execution in main",
    "This command creates an instance of the current program, but stops"
    "\nexecution immediately.\n",

  addCommand("kill", new BuiltinCLICommand(
    "Kills the execution of the current program being debugged", "",

  addCommand("quit", new BuiltinCLICommand(
    "Exit the debugger", "",

  // Program execution commands
  addCommand("run", C = new BuiltinCLICommand(
    "Start the program running from the beginning", "",
  addCommand("r", C);

  addCommand("cont", C = new BuiltinCLICommand(
    "Continue program being debugged until the next stop point", "",
  addCommand("c", C); addCommand("fg", C);

  addCommand("step", C = new BuiltinCLICommand(
    "Step program until it reaches a new source line", "",
  addCommand("s", C);

  addCommand("next", C = new BuiltinCLICommand(
    "Step program until it reaches a new source line, stepping over calls", "",
  addCommand("n", C);

  addCommand("finish", new BuiltinCLICommand(
    "Execute until the selected stack frame returns",
   "Upon return, the value returned is printed and put in the value history.\n",

  // Stack frame commands
  addCommand("backtrace", C = new BuiltinCLICommand(
   "Print backtrace of all stack frames, or innermost COUNT frames",
   "FIXME: describe.  Takes 'n', '-n' or 'full'\n",
  addCommand("bt", C);

  addCommand("up", new BuiltinCLICommand(
    "Select and print stack frame that called this one",
    "An argument says how many frames up to go.\n",

  addCommand("down", new BuiltinCLICommand(
    "Select and print stack frame called by this one",
    "An argument says how many frames down go.\n",

  addCommand("frame", C = new BuiltinCLICommand(
    "Select and print a stack frame",
 "With no argument, print the selected stack frame.  (See also 'info frame').\n"
 "An argument specifies the frame to select.\n",
  addCommand("f", C);

  // Breakpoint related commands
  addCommand("break", C = new BuiltinCLICommand(
   "Set breakpoint at specified line or function",
   "FIXME: describe.\n",
  addCommand("b", C);

  // Miscellaneous commands
  addCommand("info", new BuiltinCLICommand(
    "Generic command for showing things about the program being debugged",
    "info functions: display information about functions in the program.\ninfo"
    " source : display information about the current source file.\ninfo source"
    "s : Display source file names for the program\ninfo target : print status"
    " of inferior process\n",

  addCommand("list", C = new BuiltinCLICommand(
    "List specified function or line",
    "FIXME: document\n",
  addCommand("l", C);

  addCommand("set", new BuiltinCLICommand(
    "Change program or debugger variable",
    "FIXME: document\n",

  addCommand("show", new BuiltinCLICommand(
    "Generic command for showing things about the debugger",
    "FIXME: document\n",

  addCommand("help", C = new BuiltinCLICommand(
    "Prints information about available commands", "",
  addCommand("h", C);

/// addCommand - Add a command to the CommandTable, potentially displacing a
/// preexisting command.
void CLIDebugger::addCommand(const std::string &Option, CLICommand *Cmd) {
  assert(Cmd && "Cannot set a null command!");
  CLICommand *&CS = CommandTable[Option];
  if (CS == Cmd) return; // noop

  // If we already have a command, decrement the command's reference count.
  if (CS) {
  CS = Cmd;

  // Remember that we are using this command.

static bool isValidPrefix(const std::string &Prefix, const std::string &Option){
  return Prefix.size() <= Option.size() &&
         Prefix == std::string(Option.begin(), Option.begin()+Prefix.size());

/// getCommand - This looks up the specified command using a fuzzy match.
/// If the string exactly matches a command or is an unambiguous prefix of a
/// command, it returns the command.  Otherwise it throws an exception
/// indicating the possible ambiguous choices.
CLICommand *CLIDebugger::getCommand(const std::string &Command) {

  // Look up the command in the table.
  std::map<std::string, CLICommand*>::iterator CI =

  if (Command == "") {
    throw "Null command should not get here!";
  } else if (CI == CommandTable.end() ||
             !isValidPrefix(Command, CI->first)) {
    // If this command has no relation to anything in the command table,
    // print the error message.
    throw "Unknown command: '" + Command +
          "'.  Use 'help' for list of commands.";
  } else if (CI->first == Command) {
    // We have an exact match on the command
    return CI->second;
  } else {
    // Otherwise, we have a prefix match.  Check to see if this is
    // unambiguous, and if so, run it.
    std::map<std::string, CLICommand*>::iterator CI2 = CI;

    // If the next command is a valid completion of this one, we are
    // ambiguous.
    if (++CI2 != CommandTable.end() && isValidPrefix(Command, CI2->first)) {
      std::string ErrorMsg =
        "Ambiguous command '" + Command + "'.  Options: " + CI->first;
      for (++CI; CI != CommandTable.end() &&
             isValidPrefix(Command, CI->first); ++CI)
        ErrorMsg += ", " + CI->first;
      throw ErrorMsg;
    } else {
      // It's an unambiguous prefix of a command, use it.
      return CI->second;

/// run - Start the debugger, returning when the user exits the debugger.  This
/// starts the main event loop of the CLI debugger.
int CLIDebugger::run() {
  std::string Command;
  std::cout << Prompt;

  // Keep track of the last command issued, so that we can reissue it if the
  // user hits enter as the command.
  CLICommand *LastCommand = 0;
  std::string LastArgs;

  // Continue reading commands until the end of file.
  while (getline(std::cin, Command)) {
    std::string Arguments = Command;

    // Split off the command from the arguments to the command.
    Command = getToken(Arguments, " \t\n\v\f\r\\/;.*&");

    try {
      CLICommand *CurCommand;

      if (Command == "") {
        CurCommand = LastCommand;
        Arguments = LastArgs;
      } else {
        CurCommand = getCommand(Command);

      // Save the command we are running in case the user wants us to repeat it
      // next time.
      LastCommand = CurCommand;
      LastArgs = Arguments;

      // Finally, execute the command.
      if (CurCommand)
        CurCommand->runCommand(*this, Arguments);

    } catch (int RetVal) {
      // The quit command exits the command loop by throwing an integer return
      // code.
      return RetVal;
    } catch (const std::string &Error) {
      std::cout << "Error: " << Error << "\n";
    } catch (const char *Error) {
      std::cout << "Error: " << Error << "\n";
    } catch (const NonErrorException &E) {
      std::cout << E.getMessage() << "\n";
    } catch (...) {
      std::cout << "ERROR: Debugger caught unexpected exception!\n";
      // Attempt to continue.

    // Write the prompt to get the next bit of user input
    std::cout << Prompt;

  return 0;

/// askYesNo - Ask the user a question, and demand a yes/no response.  If
/// the user says yes, return true.
bool CLIDebugger::askYesNo(const std::string &Message) const {
  std::string Answer;
  std::cout << Message << " (y or n) " << std::flush;
  while (getline(std::cin, Answer)) {
    std::string Val = getToken(Answer);
    if (getToken(Answer).empty()) {
      if (Val == "yes" || Val == "y" || Val == "YES" || Val == "Y" ||
          Val == "Yes")
        return true;
      if (Val == "no" || Val == "n" || Val == "NO" || Val == "N" ||
          Val == "No")
        return false;

    std::cout << "Please answer y or n.\n" << Message << " (y or n) "
              << std::flush;

  // Ran out of input?
  return false;