tools/llvm-db/CLIDebugger.cpp

   1 //===-- CLIDebugger.cpp - Command Line Interface to the Debugger ----------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file contains the main implementation of the Command Line Interface to
  11 // the debugger.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "CLIDebugger.h"
  16 #include "CLICommand.h"
  17 #include "llvm/Debugger/SourceFile.h"
  18 #include "llvm/ADT/StringExtras.h"
  19 #include <iostream>
  20 using namespace llvm;
  21
  22 /// CLIDebugger constructor - This initializes the debugger to its default
  23 /// state, and initializes the command table.
  24 ///
  25 CLIDebugger::CLIDebugger(LLVMContext& ctxt)
  26   : Context(ctxt), TheProgramInfo(0), TheRuntimeInfo(0),
  27     Prompt("(llvm-db) "), ListSize(10) {
  28   // Initialize instance variables
  29   CurrentFile = 0;
  30   LineListedStart = 1;
  31   LineListedEnd = 1;
  32   LastCurrentFrame = 0;
  33   CurrentLanguage = 0;
  34
  35   CLICommand *C;
  36   //===--------------------------------------------------------------------===//
  37   // Program startup and shutdown options
  38   //
  39   addCommand("file", new BuiltinCLICommand(
  40     "Use specified file as the program to be debugged",
  41     "The debugger looks in the current directory and the program $PATH for the"
  42     " specified LLVM program.  It then unloads the currently loaded program and"
  43     " loads the specified program.\n",
  44     &CLIDebugger::fileCommand));
  45
  46   addCommand("create", new BuiltinCLICommand(
  47     "Start the program, halting its execution in main",
  48     "This command creates an instance of the current program, but stops"
  49     "\nexecution immediately.\n",
  50     &CLIDebugger::createCommand));
  51
  52   addCommand("kill", new BuiltinCLICommand(
  53     "Kills the execution of the current program being debugged", "",
  54     &CLIDebugger::killCommand));
  55
  56   addCommand("quit", new BuiltinCLICommand(
  57     "Exit the debugger", "",
  58     &CLIDebugger::quitCommand));
  59
  60   //===--------------------------------------------------------------------===//
  61   // Program execution commands
  62   //
  63   addCommand("run", C = new BuiltinCLICommand(
  64     "Start the program running from the beginning", "",
  65     &CLIDebugger::runCommand));
  66   addCommand("r", C);
  67
  68   addCommand("cont", C = new BuiltinCLICommand(
  69     "Continue program being debugged until the next stop point", "",
  70     &CLIDebugger::contCommand));
  71   addCommand("c", C); addCommand("fg", C);
  72
  73   addCommand("step", C = new BuiltinCLICommand(
  74     "Step program until it reaches a new source line", "",
  75     &CLIDebugger::stepCommand));
  76   addCommand("s", C);
  77
  78   addCommand("next", C = new BuiltinCLICommand(
  79     "Step program until it reaches a new source line, stepping over calls", "",
  80     &CLIDebugger::nextCommand));
  81   addCommand("n", C);
  82
  83   addCommand("finish", new BuiltinCLICommand(
  84     "Execute until the selected stack frame returns",
  85    "Upon return, the value returned is printed and put in the value history.\n",
  86     &CLIDebugger::finishCommand));
  87
  88   //===--------------------------------------------------------------------===//
  89   // Stack frame commands
  90   //
  91   addCommand("backtrace", C = new BuiltinCLICommand(
  92    "Print backtrace of all stack frames, or innermost COUNT frames",
  93    "FIXME: describe.  Takes 'n', '-n' or 'full'\n",
  94     &CLIDebugger::backtraceCommand));
  95   addCommand("bt", C);
  96
  97   addCommand("up", new BuiltinCLICommand(
  98     "Select and print stack frame that called this one",
  99     "An argument says how many frames up to go.\n",
 100     &CLIDebugger::upCommand));
 101
 102   addCommand("down", new BuiltinCLICommand(
 103     "Select and print stack frame called by this one",
 104     "An argument says how many frames down go.\n",
 105     &CLIDebugger::downCommand));
 106
 107   addCommand("frame", C = new BuiltinCLICommand(
 108     "Select and print a stack frame",
 109  "With no argument, print the selected stack frame.  (See also 'info frame').\n"
 110  "An argument specifies the frame to select.\n",
 111     &CLIDebugger::frameCommand));
 112   addCommand("f", C);
 113
 114   //===--------------------------------------------------------------------===//
 115   // Breakpoint related commands
 116   //
 117   addCommand("break", C = new BuiltinCLICommand(
 118    "Set breakpoint at specified line or function",
 119    "FIXME: describe.\n",
 120     &CLIDebugger::breakCommand));
 121   addCommand("b", C);
 122
 123
 124   //===--------------------------------------------------------------------===//
 125   // Miscellaneous commands
 126   //
 127   addCommand("info", new BuiltinCLICommand(
 128     "Generic command for showing things about the program being debugged",
 129     "info functions: display information about functions in the program.\ninfo"
 130     " source : display information about the current source file.\ninfo source"
 131     "s : Display source file names for the program\ninfo target : print status"
 132     " of inferior process\n",
 133     &CLIDebugger::infoCommand));
 134
 135   addCommand("list", C = new BuiltinCLICommand(
 136     "List specified function or line",
 137     "FIXME: document\n",
 138     &CLIDebugger::listCommand));
 139   addCommand("l", C);
 140
 141   addCommand("set", new BuiltinCLICommand(
 142     "Change program or debugger variable",
 143     "FIXME: document\n",
 144     &CLIDebugger::setCommand));
 145
 146   addCommand("show", new BuiltinCLICommand(
 147     "Generic command for showing things about the debugger",
 148     "FIXME: document\n",
 149     &CLIDebugger::showCommand));
 150
 151   addCommand("help", C = new BuiltinCLICommand(
 152     "Prints information about available commands", "",
 153     &CLIDebugger::helpCommand));
 154   addCommand("h", C);
 155 }
 156
 157
 158 /// addCommand - Add a command to the CommandTable, potentially displacing a
 159 /// preexisting command.
 160 void CLIDebugger::addCommand(const std::string &Option, CLICommand *Cmd) {
 161   assert(Cmd && "Cannot set a null command!");
 162   CLICommand *&CS = CommandTable[Option];
 163   if (CS == Cmd) return; // noop
 164
 165   // If we already have a command, decrement the command's reference count.
 166   if (CS) {
 167     CS->removeOptionName(Option);
 168     CS->dropRef();
 169   }
 170   CS = Cmd;
 171
 172   // Remember that we are using this command.
 173   Cmd->addRef();
 174   Cmd->addOptionName(Option);
 175 }
 176
 177 static bool isValidPrefix(const std::string &Prefix, const std::string &Option){
 178   return Prefix.size() <= Option.size() &&
 179          Prefix == std::string(Option.begin(), Option.begin()+Prefix.size());
 180 }
 181
 182 /// getCommand - This looks up the specified command using a fuzzy match.
 183 /// If the string exactly matches a command or is an unambiguous prefix of a
 184 /// command, it returns the command.  Otherwise it throws an exception
 185 /// indicating the possible ambiguous choices.
 186 CLICommand *CLIDebugger::getCommand(const std::string &Command) {
 187
 188   // Look up the command in the table.
 189   std::map<std::string, CLICommand*>::iterator CI =
 190     CommandTable.lower_bound(Command);
 191
 192   if (Command == "") {
 193     throw "Null command should not get here!";
 194   } else if (CI == CommandTable.end() ||
 195              !isValidPrefix(Command, CI->first)) {
 196     // If this command has no relation to anything in the command table,
 197     // print the error message.
 198     throw "Unknown command: '" + Command +
 199           "'.  Use 'help' for list of commands.";
 200   } else if (CI->first == Command) {
 201     // We have an exact match on the command
 202     return CI->second;
 203   } else {
 204     // Otherwise, we have a prefix match.  Check to see if this is
 205     // unambiguous, and if so, run it.
 206     std::map<std::string, CLICommand*>::iterator CI2 = CI;
 207
 208     // If the next command is a valid completion of this one, we are
 209     // ambiguous.
 210     if (++CI2 != CommandTable.end() && isValidPrefix(Command, CI2->first)) {
 211       std::string ErrorMsg =
 212         "Ambiguous command '" + Command + "'.  Options: " + CI->first;
 213       for (++CI; CI != CommandTable.end() &&
 214              isValidPrefix(Command, CI->first); ++CI)
 215         ErrorMsg += ", " + CI->first;
 216       throw ErrorMsg;
 217     } else {
 218       // It's an unambiguous prefix of a command, use it.
 219       return CI->second;
 220     }
 221   }
 222 }
 223
 224
 225 /// run - Start the debugger, returning when the user exits the debugger.  This
 226 /// starts the main event loop of the CLI debugger.
 227 ///
 228 int CLIDebugger::run() {
 229   std::string Command;
 230   std::cout << Prompt;
 231
 232   // Keep track of the last command issued, so that we can reissue it if the
 233   // user hits enter as the command.
 234   CLICommand *LastCommand = 0;
 235   std::string LastArgs;
 236
 237   // Continue reading commands until the end of file.
 238   while (getline(std::cin, Command)) {
 239     std::string Arguments = Command;
 240
 241     // Split off the command from the arguments to the command.
 242     Command = getToken(Arguments, " \t\n\v\f\r\\/;.*&");
 243
 244     try {
 245       CLICommand *CurCommand;
 246
 247       if (Command == "") {
 248         CurCommand = LastCommand;
 249         Arguments = LastArgs;
 250       } else {
 251         CurCommand = getCommand(Command);
 252       }
 253
 254       // Save the command we are running in case the user wants us to repeat it
 255       // next time.
 256       LastCommand = CurCommand;
 257       LastArgs = Arguments;
 258
 259       // Finally, execute the command.
 260       if (CurCommand)
 261         CurCommand->runCommand(*this, Arguments);
 262
 263     } catch (int RetVal) {
 264       // The quit command exits the command loop by throwing an integer return
 265       // code.
 266       return RetVal;
 267     } catch (const std::string &Error) {
 268       std::cout << "Error: " << Error << "\n";
 269     } catch (const char *Error) {
 270       std::cout << "Error: " << Error << "\n";
 271     } catch (const NonErrorException &E) {
 272       std::cout << E.getMessage() << "\n";
 273     } catch (...) {
 274       std::cout << "ERROR: Debugger caught unexpected exception!\n";
 275       // Attempt to continue.
 276     }
 277
 278     // Write the prompt to get the next bit of user input
 279     std::cout << Prompt;
 280   }
 281
 282   return 0;
 283 }
 284
 285
 286 /// askYesNo - Ask the user a question, and demand a yes/no response.  If
 287 /// the user says yes, return true.
 288 ///
 289 bool CLIDebugger::askYesNo(const std::string &Message) const {
 290   std::string Answer;
 291   std::cout << Message << " (y or n) " << std::flush;
 292   while (getline(std::cin, Answer)) {
 293     std::string Val = getToken(Answer);
 294     if (getToken(Answer).empty()) {
 295       if (Val == "yes" || Val == "y" || Val == "YES" || Val == "Y" ||
 296           Val == "Yes")
 297         return true;
 298       if (Val == "no" || Val == "n" || Val == "NO" || Val == "N" ||
 299           Val == "No")
 300         return false;
 301     }
 302
 303     std::cout << "Please answer y or n.\n" << Message << " (y or n) "
 304               << std::flush;
 305   }
 306
 307   // Ran out of input?
 308   return false;
 309 }