Initial checkin of the LLVM Source-Level Debugger. This is incomplete, but

a good start.  The status is documented in docs/SourceLevelDebugging.html


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@10687 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 803 insertions, 0 deletions

diff --git a/tools/llvm-db/Commands.cpp b/tools/llvm-db/Commands.cpp
new file mode 100644
index 0000000000..9d0bcbada5
--- /dev/null
+++ b/tools/llvm-db/Commands.cpp
@@ -0,0 +1,803 @@
+//===-- Commands.cpp - Implement various commands for the CLI -------------===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+// 
+// This file implements many builtin user commands.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CLIDebugger.h"
+#include "CLICommand.h"
+#include "llvm/Debugger/ProgramInfo.h"
+#include "llvm/Debugger/RuntimeInfo.h"
+#include "llvm/Debugger/SourceLanguage.h"
+#include "llvm/Debugger/SourceFile.h"
+#include "llvm/Debugger/InferiorProcess.h"
+#include "Support/FileUtilities.h"
+#include "Support/StringExtras.h"
+#include <iostream>
+using namespace llvm;
+
+/// getCurrentLanguage - Return the current source language that the user is
+/// playing around with.  This is aquired from the current stack frame of a
+/// running program if one exists, but this value can be explicitly set by the
+/// user as well.
+const SourceLanguage &CLIDebugger::getCurrentLanguage() const {
+  // If the user explicitly switched languages with 'set language', use what
+  // they asked for.
+  if (CurrentLanguage) {
+    return *CurrentLanguage;
+  } else if (Dbg.isProgramRunning()) {
+    // Otherwise, if the program is running, infer the current language from it.
+    const GlobalVariable *FuncDesc =
+      getRuntimeInfo().getCurrentFrame().getFunctionDesc();
+    return getProgramInfo().getFunction(FuncDesc).getSourceFile().getLanguage();
+  } else {
+    // Otherwise, default to C like GDB apparently does.
+    return SourceLanguage::getCFamilyInstance();
+  }
+}
+
+/// startProgramRunning - If the program has been updated, reload it, then
+/// start executing the program.
+void CLIDebugger::startProgramRunning() {
+  eliminateRunInfo();
+
+  // If the program has been modified, reload it!
+  std::string Program = Dbg.getProgramPath();
+  if (TheProgramInfo->getProgramTimeStamp() != getFileTimestamp(Program)) {
+    std::cout << "'" << Program << "' has changed; re-reading program.\n";
+
+    // Unload an existing program.  This kills the program if necessary.
+    Dbg.unloadProgram();
+    delete TheProgramInfo;
+    TheProgramInfo = 0;
+    CurrentFile = 0;
+
+    Dbg.loadProgram(Program);
+    TheProgramInfo = new ProgramInfo(Dbg.getProgram());
+  }
+
+  std::cout << "Starting program: " << Dbg.getProgramPath() << "\n";
+  Dbg.createProgram();
+
+  // There was no current frame.
+  LastCurrentFrame = 0;
+}
+
+/// printSourceLine - Print the specified line of the current source file.
+/// If the specified line is invalid (the source file could not be loaded or
+/// the line number is out of range), don't print anything, but return true.
+bool CLIDebugger::printSourceLine(unsigned LineNo) {
+  assert(CurrentFile && "There is no current source file to print!");
+  const char *LineStart, *LineEnd;
+  CurrentFile->getSourceLine(LineNo-1, LineStart, LineEnd);
+  if (LineStart == 0) return true;
+  std::cout << LineNo;
+
+  // If this is the line the program is currently stopped at, print a marker.
+  if (Dbg.isProgramRunning()) {
+    unsigned CurLineNo, CurColNo;
+    const SourceFileInfo *CurSFI;
+    getRuntimeInfo().getCurrentFrame().getSourceLocation(CurLineNo, CurColNo,
+                                                         CurSFI);
+
+    if (CurLineNo == LineNo && CurrentFile == &CurSFI->getSourceText())
+      std::cout << " ->";
+  }
+
+  std::cout << "\t" << std::string(LineStart, LineEnd) << "\n"; 
+  return false;
+}
+
+/// printProgramLocation - Print a line of the place where the current stack
+/// frame has stopped and the source line it is on.
+///
+void CLIDebugger::printProgramLocation(bool PrintLocation) {
+  assert(Dbg.isProgramLoaded() && Dbg.isProgramRunning() &&
+         "Error program is not loaded and running!");
+
+  // Figure out where the program stopped...
+  StackFrame &SF = getRuntimeInfo().getCurrentFrame();
+  unsigned LineNo, ColNo;
+  const SourceFileInfo *FileDesc;
+  SF.getSourceLocation(LineNo, ColNo, FileDesc);
+
+  // If requested, print out some program information about WHERE we are.
+  if (PrintLocation) {
+    // FIXME: print the current function arguments
+    if (const GlobalVariable *FuncDesc = SF.getFunctionDesc())
+      std::cout << getProgramInfo().getFunction(FuncDesc).getSymbolicName();
+    else
+      std::cout << "<unknown function>";
+    
+    CurrentFile = &FileDesc->getSourceText();
+    
+    std::cout << " at " << CurrentFile->getFilename() << ":" << LineNo;
+    if (ColNo) std::cout << ":" << ColNo << "\n";
+  }
+
+  if (printSourceLine(LineNo))
+    std::cout << "<could not load source file>\n";
+  else {
+    LineListedStart = LineNo-ListSize/2+1;
+    if ((int)LineListedStart < 1) LineListedStart = 1;
+    LineListedEnd = LineListedStart+1;
+  }
+}
+
+/// eliminateRunInfo - We are about to run the program.  Forget any state
+/// about how the program used to be stopped.
+void CLIDebugger::eliminateRunInfo() {
+  delete TheRuntimeInfo;
+  TheRuntimeInfo = 0;
+}
+
+/// programStoppedSuccessfully - This method updates internal data
+/// structures to reflect the fact that the program just executed a while,
+/// and has successfully stopped.
+void CLIDebugger::programStoppedSuccessfully() {
+  assert(TheRuntimeInfo==0 && "Someone forgot to release the old RuntimeInfo!");
+
+  TheRuntimeInfo = new RuntimeInfo(TheProgramInfo, Dbg.getRunningProcess());
+
+  // FIXME: if there are any breakpoints at the current location, print them as
+  // well.
+
+  // Since the program as successfully stopped, print its location.
+  void *CurrentFrame = getRuntimeInfo().getCurrentFrame().getFrameID();
+  printProgramLocation(CurrentFrame != LastCurrentFrame);
+  LastCurrentFrame = CurrentFrame;
+}
+
+
+
+/// getUnsignedIntegerOption - Get an unsigned integer number from the Val
+/// string.  Check to make sure that the string contains an unsigned integer
+/// token, and if not, throw an exception.  If isOnlyOption is set, also throw
+/// an exception if there is extra junk at the end of the string.
+static unsigned getUnsignedIntegerOption(const char *Msg, std::string &Val,
+                                         bool isOnlyOption = true) {
+  std::string Tok = getToken(Val);
+  if (Tok.empty() || (isOnlyOption && !getToken(Val).empty()))
+    throw std::string(Msg) + " expects an unsigned integer argument.";
+  
+  char *EndPtr;
+  unsigned Result = strtoul(Tok.c_str(), &EndPtr, 0);
+  if (EndPtr != Tok.c_str()+Tok.size())
+    throw std::string(Msg) + " expects an unsigned integer argument.";
+
+  return Result;
+}
+
+/// getOptionalUnsignedIntegerOption - This method is just like
+/// getUnsignedIntegerOption, but if the argument value is not specified, a
+/// default is returned instead of causing an error.
+static unsigned 
+getOptionalUnsignedIntegerOption(const char *Msg, unsigned Default,
+                                 std::string &Val, bool isOnlyOption = true) {
+  // Check to see if the value was specified...
+  std::string TokVal = getToken(Val);
+  if (TokVal.empty()) return Default;
+
+  // If it was specified, add it back to the value we are parsing...
+  Val = TokVal+Val;
+
+  // And parse normally.
+  return getUnsignedIntegerOption(Msg, Val, isOnlyOption);
+}
+                                                 
+
+//===----------------------------------------------------------------------===//
+//                   Program startup and shutdown options
+//===----------------------------------------------------------------------===//
+
+
+/// file command - If the user specifies an option, search the PATH for the
+/// specified program/bytecode file and load it.  If the user does not specify
+/// an option, unload the current program.
+void CLIDebugger::fileCommand(std::string &Options) {
+  std::string Prog = getToken(Options);
+  if (!getToken(Options).empty())
+    throw "file command takes at most one argument.";
+
+  // Check to make sure the user knows what they are doing
+  if (Dbg.isProgramRunning() &&
+      !askYesNo("A program is already loaded.  Kill it?"))
+    return;
+
+  // Unload an existing program.  This kills the program if necessary.
+  eliminateRunInfo();
+  delete TheProgramInfo;
+  TheProgramInfo = 0;
+  Dbg.unloadProgram();
+  CurrentFile = 0;
+
+  // If requested, start the new program.
+  if (Prog.empty()) {
+    std::cout << "Unloaded program.\n";
+  } else {
+    std::cout << "Loading program... " << std::flush;
+    Dbg.loadProgram(Prog);
+    assert(Dbg.isProgramLoaded() &&
+           "loadProgram succeeded, but not program loaded!");
+    TheProgramInfo = new ProgramInfo(Dbg.getProgram());
+    std::cout << "success loading '" << Dbg.getProgramPath() << "'!\n";
+  }
+}
+
+
+void CLIDebugger::createCommand(std::string &Options) {
+  if (!getToken(Options).empty())
+    throw "create command does not take any arguments.";
+  if (!Dbg.isProgramLoaded()) throw "No program loaded.";
+  if (Dbg.isProgramRunning() &&
+      !askYesNo("The program is already running.  Restart from the beginning?"))
+    return;
+
+  // Start the program running.
+  startProgramRunning();
+
+  // The program stopped!
+  programStoppedSuccessfully();
+}
+
+void CLIDebugger::killCommand(std::string &Options) {
+  if (!getToken(Options).empty())
+    throw "kill command does not take any arguments.";
+  if (!Dbg.isProgramRunning())
+    throw "No program is currently being run.";
+
+  if (askYesNo("Kill the program being debugged?"))
+    Dbg.killProgram();
+  eliminateRunInfo();
+}
+
+void CLIDebugger::quitCommand(std::string &Options) {
+  if (!getToken(Options).empty())
+    throw "quit command does not take any arguments.";
+
+  if (Dbg.isProgramRunning() &&
+      !askYesNo("The program is running.  Exit anyway?"))
+    return;
+
+  // Throw exception to get out of the user-input loop.
+  throw 0;
+}
+
+
+//===----------------------------------------------------------------------===//
+//                        Program execution commands
+//===----------------------------------------------------------------------===//
+
+void CLIDebugger::runCommand(std::string &Options) {
+  if (!getToken(Options).empty()) throw "run arguments not supported yet.";
+  if (!Dbg.isProgramLoaded()) throw "No program loaded.";
+  if (Dbg.isProgramRunning() &&
+      !askYesNo("The program is already running.  Restart from the beginning?"))
+    return;
+
+  eliminateRunInfo();
+
+  // Start the program running.
+  startProgramRunning();
+
+  // Start the program running...
+  Options = "";
+  contCommand(Options);
+}
+
+void CLIDebugger::contCommand(std::string &Options) {
+  if (!getToken(Options).empty()) throw "cont argument not supported yet.";
+  if (!Dbg.isProgramRunning()) throw "Program is not running.";
+
+  eliminateRunInfo();
+
+  Dbg.contProgram();
+
+  // The program stopped!
+  programStoppedSuccessfully();
+}
+
+void CLIDebugger::stepCommand(std::string &Options) {
+  if (!Dbg.isProgramRunning()) throw "Program is not running.";
+
+  // Figure out how many times to step.
+  unsigned Amount =
+    getOptionalUnsignedIntegerOption("'step' command", 1, Options);
+
+  eliminateRunInfo();
+
+  // Step the specified number of times.
+  for (; Amount; --Amount)
+    Dbg.stepProgram();
+
+  // The program stopped!
+  programStoppedSuccessfully();
+}
+
+void CLIDebugger::nextCommand(std::string &Options) {
+  if (!Dbg.isProgramRunning()) throw "Program is not running.";
+  unsigned Amount =
+    getOptionalUnsignedIntegerOption("'next' command", 1, Options);
+
+  eliminateRunInfo();
+
+  for (; Amount; --Amount)
+    Dbg.nextProgram();
+
+  // The program stopped!
+  programStoppedSuccessfully();
+}
+
+void CLIDebugger::finishCommand(std::string &Options) {
+  if (!getToken(Options).empty())
+    throw "finish command does not take any arguments.";
+  if (!Dbg.isProgramRunning()) throw "Program is not running.";
+
+  // Figure out where we are exactly.  If the user requests that we return from
+  // a frame that is not the top frame, make sure we get it.
+  void *CurrentFrame = getRuntimeInfo().getCurrentFrame().getFrameID();
+
+  eliminateRunInfo();
+
+  Dbg.finishProgram(CurrentFrame);
+
+  // The program stopped!
+  programStoppedSuccessfully();
+}
+
+//===----------------------------------------------------------------------===//
+//                           Stack frame commands
+//===----------------------------------------------------------------------===//
+
+void CLIDebugger::backtraceCommand(std::string &Options) {
+  // Accepts "full", n, -n
+  if (!getToken(Options).empty())
+    throw "FIXME: bt command argument not implemented yet!";
+
+  RuntimeInfo &RI = getRuntimeInfo();
+  ProgramInfo &PI = getProgramInfo();
+
+  try {
+    for (unsigned i = 0; ; ++i) {
+      StackFrame &SF = RI.getStackFrame(i);
+      std::cout << "#" << i;
+      if (i == RI.getCurrentFrameIdx())
+        std::cout << " ->";
+      std::cout << "\t" << SF.getFrameID() << " in ";
+      if (const GlobalVariable *G = SF.getFunctionDesc())
+        std::cout << PI.getFunction(G).getSymbolicName();
+
+      unsigned LineNo, ColNo;
+      const SourceFileInfo *SFI;
+      SF.getSourceLocation(LineNo, ColNo, SFI);
+      if (!SFI->getBaseName().empty()) {
+        std::cout << " at " << SFI->getBaseName();
+        if (LineNo) {
+          std::cout << ":" << LineNo;
+          if (ColNo)
+            std::cout << ":" << ColNo;
+        }
+      }
+
+      // FIXME: when we support shared libraries, we should print ' from foo.so'
+      // if the stack frame is from a different object than the current one.
+
+      std::cout << "\n";
+    }
+  } catch (...) {
+    // Stop automatically when we run off the bottom of the stack.
+  }
+}
+
+void CLIDebugger::upCommand(std::string &Options) {
+  unsigned Num =
+    getOptionalUnsignedIntegerOption("'up' command", 1, Options);
+
+  RuntimeInfo &RI = getRuntimeInfo();
+  unsigned CurFrame = RI.getCurrentFrameIdx();
+
+  // Check to see if we go can up the specified number of frames.
+  try {
+    RI.getStackFrame(CurFrame+Num);
+  } catch (...) {
+    if (Num == 1)
+      throw "Initial frame selected; you cannot go up.";
+    else
+      throw "Cannot go up " + utostr(Num) + " frames!";
+  }
+
+  RI.setCurrentFrameIdx(CurFrame+Num);
+  printProgramLocation();
+}
+
+void CLIDebugger::downCommand(std::string &Options) {
+  unsigned Num =
+    getOptionalUnsignedIntegerOption("'down' command", 1, Options);
+
+  RuntimeInfo &RI = getRuntimeInfo();
+  unsigned CurFrame = RI.getCurrentFrameIdx();
+
+  // Check to see if we can go up the specified number of frames.
+  if (CurFrame < Num)
+    if (Num == 1)
+      throw "Bottom (i.e., innermost) frame selected; you cannot go down.";
+    else
+      throw "Cannot go down " + utostr(Num) + " frames!";
+
+  RI.setCurrentFrameIdx(CurFrame-Num);
+  printProgramLocation();
+}
+
+void CLIDebugger::frameCommand(std::string &Options) {
+  RuntimeInfo &RI = getRuntimeInfo();
+  unsigned CurFrame = RI.getCurrentFrameIdx();
+
+  unsigned Num =
+    getOptionalUnsignedIntegerOption("'frame' command", CurFrame, Options);
+
+  // Check to see if we go to the specified frame.
+  RI.getStackFrame(Num);
+
+  RI.setCurrentFrameIdx(Num);
+  printProgramLocation();
+}
+
+
+//===----------------------------------------------------------------------===//
+//                        Breakpoint related commands
+//===----------------------------------------------------------------------===//
+
+void CLIDebugger::breakCommand(std::string &Options) {
+  throw "breakpoints not implemented yet!";
+}
+
+//===----------------------------------------------------------------------===//
+//                          Miscellaneous commands
+//===----------------------------------------------------------------------===//
+
+void CLIDebugger::infoCommand(std::string &Options) {
+  std::string What = getToken(Options);
+
+  if (What.empty() || !getToken(Options).empty())
+    throw "info command expects exactly one argument.";
+
+  if (What == "frame") {
+  } else if (What == "functions") {
+    const std::map<const GlobalVariable*, SourceFunctionInfo*> &Functions
+      = getProgramInfo().getSourceFunctions();
+    std::cout << "All defined functions:\n";
+    // FIXME: GDB groups these by source file.  We could do that I guess.
+    for (std::map<const GlobalVariable*, SourceFunctionInfo*>::const_iterator
+           I = Functions.begin(), E = Functions.end(); I != E; ++I) {
+      std::cout << I->second->getSymbolicName() << "\n";
+    }
+
+  } else if (What == "source") {
+    if (CurrentFile == 0)
+      throw "No current source file.";
+
+    // Get the SourceFile information for the current file.
+    const SourceFileInfo &SF =
+      getProgramInfo().getSourceFile(CurrentFile->getDescriptor());
+
+    std::cout << "Current source file is: " << SF.getBaseName() << "\n"
+              << "Compilation directory is: " << SF.getDirectory() << "\n";
+    if (unsigned NL = CurrentFile->getNumLines())
+      std::cout << "Located in: " << CurrentFile->getFilename() << "\n"
+                << "Contains " << NL << " lines\n";
+    else
+      std::cout << "Could not find source file.\n";
+    std::cout << "Source language is "
+              << SF.getLanguage().getSourceLanguageName() << "\n";
+
+  } else if (What == "sources") {
+    const std::map<const GlobalVariable*, SourceFileInfo*> &SourceFiles = 
+      getProgramInfo().getSourceFiles();
+    std::cout << "Source files for the program:\n";
+    for (std::map<const GlobalVariable*, SourceFileInfo*>::const_iterator I =
+           SourceFiles.begin(), E = SourceFiles.end(); I != E;) {
+      std::cout << I->second->getDirectory() << "/"
+                << I->second->getBaseName();
+      ++I;
+      if (I != E) std::cout << ", ";
+    }
+    std::cout << "\n";
+  } else if (What == "target") {
+    std::cout << Dbg.getRunningProcess().getStatus();
+  } else {
+    // See if this is something handled by the current language.
+    if (getCurrentLanguage().printInfo(What))
+      return;
+
+    throw "Unknown info command '" + What + "'.  Try 'help info'.";
+  }
+}
+
+/// parseLineSpec - Parses a line specifier, for use by the 'list' command.
+/// If SourceFile is returned as a void pointer, then it was not specified.
+/// If the line specifier is invalid, an exception is thrown.
+void CLIDebugger::parseLineSpec(std::string &LineSpec,
+                                const SourceFile *&SourceFile,
+                                unsigned &LineNo) {
+  SourceFile = 0;
+  LineNo = 0;
+
+  // First, check to see if we have a : separator.
+  std::string FirstPart = getToken(LineSpec, ":");
+  std::string SecondPart = getToken(LineSpec, ":");
+  if (!getToken(LineSpec).empty()) throw "Malformed line specification!";
+
+  // If there is no second part, we must have either "function", "number",
+  // "+offset", or "-offset".
+  if (SecondPart.empty()) {
+    if (FirstPart.empty()) throw "Malformed line specification!";
+    if (FirstPart[0] == '+') {
+      FirstPart.erase(FirstPart.begin(), FirstPart.begin()+1);
+      // For +n, return LineListedEnd+n
+      LineNo = LineListedEnd +
+               getUnsignedIntegerOption("Line specifier '+'", FirstPart);
+
+    } else if (FirstPart[0] == '-') {
+      FirstPart.erase(FirstPart.begin(), FirstPart.begin()+1);
+      // For -n, return LineListedEnd-n
+      LineNo = LineListedEnd -
+               getUnsignedIntegerOption("Line specifier '-'", FirstPart);
+      if ((int)LineNo < 1) LineNo = 1;
+    } else if (FirstPart[0] == '*') {
+      throw "Address expressions not supported as source locations!";
+    } else {
+      // Ok, check to see if this is just a line number.
+      std::string Saved = FirstPart;
+      try {
+        LineNo = getUnsignedIntegerOption("", Saved);
+      } catch (...) {
+        // Ok, it's not a valid line number.  It must be a source-language
+        // entity name.
+        std::string Name = getToken(FirstPart);
+        if (!getToken(FirstPart).empty())
+          throw "Extra junk in line specifier after '" + Name + "'.";
+        SourceFunctionInfo *SFI = 
+          getCurrentLanguage().lookupFunction(Name, getProgramInfo(),
+                                              TheRuntimeInfo);
+        if (SFI == 0)
+          throw "Unknown identifier '" + Name + "'.";
+
+        unsigned L, C;
+        SFI->getSourceLocation(L, C);
+        if (L == 0) throw "Could not locate '" + Name + "'!";
+        LineNo = L;
+        SourceFile = &SFI->getSourceFile().getSourceText();
+        return;
+      }
+    }
+
+  } else {
+    // Ok, this must be a filename qualified line number or function name.
+    // First, figure out the source filename.
+    std::string SourceFilename = getToken(FirstPart);
+    if (!getToken(FirstPart).empty())
+      throw "Invalid filename qualified source location!";
+
+    // Next, check to see if this is just a line number.
+    std::string Saved = SecondPart;
+    try {
+      LineNo = getUnsignedIntegerOption("", Saved);
+    } catch (...) {
+      // Ok, it's not a valid line number.  It must be a function name.
+      throw "FIXME: Filename qualified function names are not support "
+            "as line specifiers yet!";
+    }
+
+    // Ok, we got the line number.  Now check out the source file name to make
+    // sure it's all good.  If it is, return it.  If not, throw exception.
+    SourceFile =&getProgramInfo().getSourceFile(SourceFilename).getSourceText();
+  }
+}
+
+void CLIDebugger::listCommand(std::string &Options) {
+  if (!Dbg.isProgramLoaded())
+    throw "No program is loaded.  Use the 'file' command.";
+
+  // Handle "list foo," correctly, by returning " " as the second token
+  Options += " ";
+  
+  std::string FirstLineSpec = getToken(Options, ",");
+  std::string SecondLineSpec = getToken(Options, ",");
+  if (!getToken(Options, ",").empty())
+    throw "list command only expects two source location specifiers!";
+
+  // StartLine, EndLine - The starting and ending line numbers to print.
+  unsigned StartLine = 0, EndLine = 0;
+
+  if (SecondLineSpec.empty()) {    // No second line specifier provided?
+    // Handle special forms like "", "+", "-", etc.
+    std::string TmpSpec = FirstLineSpec;
+    std::string Tok = getToken(TmpSpec);
+    if (getToken(TmpSpec).empty() && (Tok == "" || Tok == "+" || Tok == "-")) {
+      if (Tok == "+" || Tok == "") {
+        StartLine = LineListedEnd;
+        EndLine = StartLine + ListSize;
+      } else {
+        assert(Tok == "-");
+        StartLine = LineListedStart-ListSize;
+        EndLine = LineListedStart;
+        if ((int)StartLine < 0) StartLine = 1;
+      }
+    } else {
+      // Must be a normal line specifier.
+      const SourceFile *File;
+      unsigned LineNo;
+      parseLineSpec(FirstLineSpec, File, LineNo);
+
+      // If the user only specified one file specifier, we should display
+      // ListSize lines centered at the specified line.
+      if (File != 0) CurrentFile = File;
+      StartLine = LineNo - (ListSize+1)/2;
+      if ((int)StartLine < 0) StartLine = 1;
+      EndLine = StartLine + ListSize;
+    }
+
+  } else {
+    // Parse two line specifiers... 
+    const SourceFile *StartFile, *EndFile;
+    unsigned StartLineNo, EndLineNo;
+    parseLineSpec(FirstLineSpec, StartFile, StartLineNo);
+    unsigned SavedLLE = LineListedEnd;
+    LineListedEnd = StartLineNo;
+    try {
+      parseLineSpec(SecondLineSpec, EndFile, EndLineNo);
+    } catch (...) {
+      LineListedEnd = SavedLLE;
+      throw;
+    }
+
+    // Inherit file specified by the first line spec if there was one.
+    if (EndFile == 0) EndFile = StartFile;
+
+    if (StartFile != EndFile)
+      throw "Start and end line specifiers are in different files!";
+    CurrentFile = StartFile;
+    StartLine = StartLineNo;
+    EndLine = EndLineNo+1;
+  }
+
+  assert((int)StartLine > 0 && (int)EndLine > 0 && StartLine <= EndLine &&
+         "Error reading line specifiers!");
+
+  // If there was no current file, and the user didn't specify one to list, we
+  // have an error.
+  if (CurrentFile == 0)
+    throw "There is no current file to list.";
+
+  // Remember for next time.
+  LineListedStart = StartLine;
+  LineListedEnd = StartLine;
+
+  for (unsigned LineNo = StartLine; LineNo != EndLine; ++LineNo) {
+    // Print the source line, unless it is invalid.
+    if (printSourceLine(LineNo))
+      break;
+    LineListedEnd = LineNo+1;
+  }
+
+  // If we didn't print any lines, find out why.
+  if (LineListedEnd == StartLine) {
+    // See if we can read line #0 from the file, if not, we couldn't load the
+    // file.
+    const char *LineStart, *LineEnd;
+    CurrentFile->getSourceLine(0, LineStart, LineEnd);
+    if (LineStart == 0)
+      throw "Could not load source file '" + CurrentFile->getFilename() + "'!";
+    else
+      std::cout << "<end of file>\n";
+  }
+}
+
+void CLIDebugger::setCommand(std::string &Options) {
+  std::string What = getToken(Options);
+
+  if (What.empty())
+    throw "set command expects at least two arguments.";
+  if (What == "language") {
+    std::string Lang = getToken(Options);
+    if (!getToken(Options).empty())
+      throw "set language expects one argument at most.";
+    if (Lang == "") {
+      std::cout << "The currently understood settings are:\n\n"
+                << "local or auto  Automatic setting based on source file\n"
+                << "c              Use the C language\n"
+                << "c++            Use the C++ language\n"
+                << "unknown        Use when source language is not supported\n";
+    } else if (Lang == "local" || Lang == "auto") {
+      CurrentLanguage = 0;
+    } else if (Lang == "c") {
+      CurrentLanguage = &SourceLanguage::getCFamilyInstance();
+    } else if (Lang == "c++") {
+      CurrentLanguage = &SourceLanguage::getCPlusPlusInstance();
+    } else if (Lang == "unknown") {
+      CurrentLanguage = &SourceLanguage::getUnknownLanguageInstance();
+    } else {
+      throw "Unknown language '" + Lang + "'.";
+    }
+
+  } else if (What == "listsize") {
+    ListSize = getUnsignedIntegerOption("'set prompt' command", Options);
+  } else if (What == "prompt") {
+    // Include any trailing whitespace or other tokens, but not leading
+    // whitespace.
+    Prompt = getToken(Options);  // Strip leading whitespace
+    Prompt += Options;           // Keep trailing whitespace or other stuff
+  } else {
+    // FIXME: Try to parse this as a source-language program expression.
+    throw "Don't know how to set '" + What + "'!";
+  }
+}
+
+void CLIDebugger::showCommand(std::string &Options) {
+  std::string What = getToken(Options);
+
+  if (What.empty() || !getToken(Options).empty())
+    throw "show command expects one argument.";
+
+  if (What == "language") {
+    std::cout << "The current source language is '";
+    if (CurrentLanguage)
+      std::cout << CurrentLanguage->getSourceLanguageName();
+    else
+      std::cout << "auto; currently "
+                << getCurrentLanguage().getSourceLanguageName();
+    std::cout << "'.\n";
+  } else if (What == "listsize") {
+    std::cout << "Number of source lines llvm-db will list by default is "
+              << ListSize << ".\n";
+  } else if (What == "prompt") {
+    std::cout << "llvm-db's prompt is \"" << Prompt << "\".\n";
+  } else {
+    throw "Unknown show command '" + What + "'.  Try 'help show'.";
+  }
+}
+
+void CLIDebugger::helpCommand(std::string &Options) {
+  // Print out all of the commands in the CommandTable
+  std::string Command = getToken(Options);
+  if (!getToken(Options).empty())
+    throw "help command takes at most one argument.";
+
+  // Getting detailed help on a particular command?
+  if (!Command.empty()) {
+    CLICommand *C = getCommand(Command);
+    std::cout << C->getShortHelp() << ".\n" << C->getLongHelp();
+
+    // If there are aliases for this option, print them out.
+    const std::vector<std::string> &Names = C->getOptionNames();
+    if (Names.size() > 1) {
+      std::cout << "The '" << Command << "' command is known as: '"
+                << Names[0] << "'";
+      for (unsigned i = 1, e = Names.size(); i != e; ++i)
+        std::cout << ", '" << Names[i] << "'";
+      std::cout << "\n";
+    }
+
+  } else {
+    unsigned MaxSize = 0;
+    for (std::map<std::string, CLICommand*>::iterator I = CommandTable.begin(),
+           E = CommandTable.end(); I != E; ++I)
+      if (I->first.size() > MaxSize &&
+          I->first == I->second->getPrimaryOptionName())
+        MaxSize = I->first.size();
+
+    // Loop over all of the commands, printing the short help version
+    for (std::map<std::string, CLICommand*>::iterator I = CommandTable.begin(),
+           E = CommandTable.end(); I != E; ++I)
+      if (I->first == I->second->getPrimaryOptionName())
+        std::cout << I->first << std::string(MaxSize - I->first.size(), ' ')
+                  << " - " << I->second->getShortHelp() << "\n";
+  }
+}