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//===-- Debugger.cpp - LLVM debugger library implementation ---------------===//
//
// 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 LLVM debugger library.
//
//===----------------------------------------------------------------------===//
#include "llvm/Debugger/Debugger.h"
#include "llvm/Module.h"
#include "llvm/ModuleProvider.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/Debugger/InferiorProcess.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/ADT/StringExtras.h"
#include <cstdlib>
#include <memory>
using namespace llvm;
/// Debugger constructor - Initialize the debugger to its initial, empty, state.
///
Debugger::Debugger() : Environment(0), Program(0), Process(0) {
}
Debugger::~Debugger() {
// Killing the program could throw an exception. We don't want to progagate
// the exception out of our destructor though.
try {
killProgram();
} catch (const char *) {
} catch (const std::string &) {
}
unloadProgram();
}
/// getProgramPath - Get the path of the currently loaded program, or an
/// empty string if none is loaded.
std::string Debugger::getProgramPath() const {
return Program ? Program->getModuleIdentifier() : "";
}
static Module *
getMaterializedModuleProvider(const std::string &Filename,
const LLVMContext& C) {
std::auto_ptr<MemoryBuffer> Buffer;
Buffer.reset(MemoryBuffer::getFileOrSTDIN(Filename.c_str()));
if (Buffer.get())
return ParseBitcodeFile(Buffer.get(), C);
return 0;
}
/// loadProgram - If a program is currently loaded, unload it. Then search
/// the PATH for the specified program, loading it when found. If the
/// specified program cannot be found, an exception is thrown to indicate the
/// error.
void Debugger::loadProgram(const std::string &Filename, const LLVMContext& C) {
if ((Program = getMaterializedModuleProvider(Filename, C)) ||
(Program = getMaterializedModuleProvider(Filename+".bc", C)))
return; // Successfully loaded the program.
// Search the program path for the file...
if (const char *PathS = getenv("PATH")) {
std::string Path = PathS;
std::string Directory = getToken(Path, ":");
while (!Directory.empty()) {
if ((Program = getMaterializedModuleProvider(Directory +"/"+ Filename, C))
|| (Program = getMaterializedModuleProvider(Directory +"/"+ Filename
+ ".bc", C)))
return; // Successfully loaded the program.
Directory = getToken(Path, ":");
}
}
throw "Could not find program '" + Filename + "'!";
}
/// unloadProgram - If a program is running, kill it, then unload all traces
/// of the current program. If no program is loaded, this method silently
/// succeeds.
void Debugger::unloadProgram() {
if (!isProgramLoaded()) return;
killProgram();
delete Program;
Program = 0;
}
/// createProgram - Create an instance of the currently loaded program,
/// killing off any existing one. This creates the program and stops it at
/// the first possible moment. If there is no program loaded or if there is a
/// problem starting the program, this method throws an exception.
void Debugger::createProgram() {
if (!isProgramLoaded())
throw "Cannot start program: none is loaded.";
// Kill any existing program.
killProgram();
// Add argv[0] to the arguments vector..
std::vector<std::string> Args(ProgramArguments);
Args.insert(Args.begin(), getProgramPath());
// Start the new program... this could throw if the program cannot be started.
Process = InferiorProcess::create(Program, Args, Environment);
}
InferiorProcess *
InferiorProcess::create(Module *M, const std::vector<std::string> &Arguments,
const char * const *envp) {
throw"No supported binding to inferior processes (debugger not implemented).";
}
/// killProgram - If the program is currently executing, kill off the
/// process and free up any state related to the currently running program. If
/// there is no program currently running, this just silently succeeds.
void Debugger::killProgram() {
// The destructor takes care of the dirty work.
try {
delete Process;
} catch (...) {
Process = 0;
throw;
}
Process = 0;
}
/// stepProgram - Implement the 'step' command, continuing execution until
/// the next possible stop point.
void Debugger::stepProgram() {
assert(isProgramRunning() && "Cannot step if the program isn't running!");
try {
Process->stepProgram();
} catch (InferiorProcessDead &IPD) {
killProgram();
throw NonErrorException("The program stopped with exit code " +
itostr(IPD.getExitCode()));
} catch (...) {
killProgram();
throw;
}
}
/// nextProgram - Implement the 'next' command, continuing execution until
/// the next possible stop point that is in the current function.
void Debugger::nextProgram() {
assert(isProgramRunning() && "Cannot next if the program isn't running!");
try {
// This should step the process. If the process enters a function, then it
// should 'finish' it. However, figuring this out is tricky. In
// particular, the program can do any of:
// 0. Not change current frame.
// 1. Entering or exiting a region within the current function
// (which changes the frame ID, but which we shouldn't 'finish')
// 2. Exiting the current function (which changes the frame ID)
// 3. Entering a function (which should be 'finish'ed)
// For this reason, we have to be very careful about when we decide to do
// the 'finish'.
// Get the current frame, but don't trust it. It could change...
void *CurrentFrame = Process->getPreviousFrame(0);
// Don't trust the current frame: get the caller frame.
void *ParentFrame = Process->getPreviousFrame(CurrentFrame);
// Ok, we have some information, run the program one step.
Process->stepProgram();
// Where is the new frame? The most common case, by far is that it has not
// been modified (Case #0), in which case we don't need to do anything more.
void *NewFrame = Process->getPreviousFrame(0);
if (NewFrame != CurrentFrame) {
// Ok, the frame changed. If we are case #1, then the parent frame will
// be identical.
void *NewParentFrame = Process->getPreviousFrame(NewFrame);
if (ParentFrame != NewParentFrame) {
// Ok, now we know we aren't case #0 or #1. Check to see if we entered
// a new function. If so, the parent frame will be "CurrentFrame".
if (CurrentFrame == NewParentFrame)
Process->finishProgram(NewFrame);
}
}
} catch (InferiorProcessDead &IPD) {
killProgram();
throw NonErrorException("The program stopped with exit code " +
itostr(IPD.getExitCode()));
} catch (...) {
killProgram();
throw;
}
}
/// finishProgram - Implement the 'finish' command, continuing execution
/// until the specified frame ID returns.
void Debugger::finishProgram(void *Frame) {
assert(isProgramRunning() && "Cannot cont if the program isn't running!");
try {
Process->finishProgram(Frame);
} catch (InferiorProcessDead &IPD) {
killProgram();
throw NonErrorException("The program stopped with exit code " +
itostr(IPD.getExitCode()));
} catch (...) {
killProgram();
throw;
}
}
/// contProgram - Implement the 'cont' command, continuing execution until
/// the next breakpoint is encountered.
void Debugger::contProgram() {
assert(isProgramRunning() && "Cannot cont if the program isn't running!");
try {
Process->contProgram();
} catch (InferiorProcessDead &IPD) {
killProgram();
throw NonErrorException("The program stopped with exit code " +
itostr(IPD.getExitCode()));
} catch (...) {
killProgram();
throw;
}
}
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