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[kdbg.git] / kdbg / dbgdriver.cpp

// $Id$

// Copyright by Johannes Sixt
// This file is under GPL, the GNU General Public Licence

#include "dbgdriver.h"
#include "exprwnd.h"
#include "valarray.h"
#include <ctype.h>
#include <stdlib.h>                     /* strtol, atoi */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "mydebug.h"
#include <assert.h>


DebuggerDriver::DebuggerDriver() :
        KProcess(),
        m_state(DSidle),
        m_output(0),
        m_outputLen(0),
        m_outputAlloc(0),
        m_activeCmd(0),
        m_promptMinLen(0),
        m_promptLastChar('\0')
{
    m_outputAlloc = 4000;
    m_output = new char[m_outputAlloc];

    m_prompt[0] = '\0';
    // Derived classes can set either m_prompt or m_promptRE.
    // If m_promptRE is set, it must include the '$' at the end.
    // m_promptLastChar and m_promptMinLen must also be set.

    m_hipriCmdQueue.setAutoDelete(true);

    // debugger process
    connect(this, SIGNAL(receivedStdout(KProcess*,char*,int)),
            SLOT(slotReceiveOutput(KProcess*,char*,int)));
    connect(this, SIGNAL(wroteStdin(KProcess*)), SLOT(slotCommandRead(KProcess*)));
    connect(this, SIGNAL(processExited(KProcess*)), SLOT(slotExited(KProcess*)));
}

DebuggerDriver::~DebuggerDriver()
{
    delete[] m_output;
}

int DebuggerDriver::commSetupDoneC()
{
    TRACE(__PRETTY_FUNCTION__);

    if (!KProcess::commSetupDoneC())
        return 0;

    close(STDERR_FILENO);
    return dup2(STDOUT_FILENO, STDERR_FILENO) != -1;
}

static void splitCmdStr(const QString& cmd, ValArray<QString>& parts)
{
    QString str = cmd.simplifyWhiteSpace();
    int start = 0;
    int end;
    while ((end = str.find(' ', start)) >= 0) {
        parts.append(str.mid(start, end-start));
        start = end+1;
    }
    parts.append(str.mid(start, str.length()-start));
}


bool DebuggerDriver::startup(QString cmdStr)
{
    // clear command queues
    delete m_activeCmd;
    m_activeCmd = 0;
    m_hipriCmdQueue.clear();
    bool autodel = m_lopriCmdQueue.autoDelete();
    m_lopriCmdQueue.setAutoDelete(true);
    m_lopriCmdQueue.clear();
    m_lopriCmdQueue.setAutoDelete(autodel);
    m_state = DSidle;

    // debugger executable
    if (cmdStr.isEmpty())
        cmdStr = defaultInvocation();

    ValArray<QString> cmd;
    splitCmdStr(cmdStr, cmd);
    clearArguments();
    for (int i = 0; i < cmd.size(); i++) {
        *this << cmd[i];
    }

    if (!start(KProcess::NotifyOnExit,
               KProcess::Communication(KProcess::Stdin|KProcess::Stdout))) {
        return false;
    }

    // open log file
    if (!m_logFile.isOpen() && !m_logFileName.isEmpty()) {
        m_logFile.setName(m_logFileName);
        m_logFile.open(IO_WriteOnly);
    }

    // these must be set by derived classes in their constructor
    assert(m_promptMinLen > 0);         // _must_ have a prompt
    assert(m_promptLastChar != '\0');   // last char _must_ be fixed
    assert(m_prompt[0] == '\0' || strlen(m_prompt) == m_promptMinLen);
    // either a prompt or a regexp
    assert(m_prompt[0] != '\0' && m_promptMinLen < sizeof(m_prompt) ||
           !m_promptRE.isEmpty() && m_promptRE.isValid());

    return true;
}

void DebuggerDriver::slotExited(KProcess*)
{
    static const char txt[] = "\n====== debugger exited ======\n";
    if (m_logFile.isOpen()) {
        m_logFile.writeBlock(txt,sizeof(txt)-1);
    }

    // reset state
    m_state = DSidle;
    // empty buffer
    m_outputLen = 0;
    *m_output = '\0';
}


CmdQueueItem* DebuggerDriver::executeCmdString(DbgCommand cmd,
                                               QString cmdString, bool clearLow)
{
    // place a new command into the high-priority queue
    CmdQueueItem* cmdItem = new CmdQueueItem(cmd, cmdString);
    m_hipriCmdQueue.enqueue(cmdItem);

    if (clearLow) {
        if (m_state == DSrunningLow) {
            // take the liberty to interrupt the running command
            m_state = DSinterrupted;
            kill(SIGINT);
            ASSERT(m_activeCmd != 0);
            TRACE(QString().sprintf("interrupted the command %d",
                  (m_activeCmd ? m_activeCmd->m_cmd : -1)));
            delete m_activeCmd;
            m_activeCmd = 0;
        }
        flushLoPriQueue();
    }
    // if gdb is idle, send it the command
    if (m_state == DSidle) {
        ASSERT(m_activeCmd == 0);
        writeCommand();
    }

    return cmdItem;
}

CmdQueueItem* DebuggerDriver::queueCmdString(DbgCommand cmd,
                                             QString cmdString, QueueMode mode)
{
    // place a new command into the low-priority queue
    CmdQueueItem* cmdItem = 0;
    switch (mode) {
    case QMoverrideMoreEqual:
    case QMoverride:
        // check whether gdb is currently processing this command
        if (m_activeCmd != 0 &&
            m_activeCmd->m_cmd == cmd && m_activeCmd->m_cmdString == cmdString)
        {
            return m_activeCmd;
        }
        // check whether there is already the same command in the queue
        for (cmdItem = m_lopriCmdQueue.first(); cmdItem != 0; cmdItem = m_lopriCmdQueue.next()) {
            if (cmdItem->m_cmd == cmd && cmdItem->m_cmdString == cmdString)
                break;
        }
        if (cmdItem != 0) {
            // found one
            if (mode == QMoverrideMoreEqual) {
                // All commands are equal, but some are more equal than others...
                // put this command in front of all others
                m_lopriCmdQueue.take();
                m_lopriCmdQueue.insert(0, cmdItem);
            }
            break;
        } // else none found, so add it
        // drop through
    case QMnormal:
        cmdItem = new CmdQueueItem(cmd, cmdString);
        m_lopriCmdQueue.append(cmdItem);
    }

    // if gdb is idle, send it the command
    if (m_state == DSidle) {
        ASSERT(m_activeCmd == 0);
        writeCommand();
    }

    return cmdItem;
}

// dequeue a pending command, make it the active one and send it to gdb
void DebuggerDriver::writeCommand()
{
//    ASSERT(m_activeCmd == 0);
    assert(m_activeCmd == 0);

    // first check the high-priority queue - only if it is empty
    // use a low-priority command.
    CmdQueueItem* cmd = m_hipriCmdQueue.dequeue();
    DebuggerState newState = DScommandSent;
    if (cmd == 0) {
        cmd = m_lopriCmdQueue.first();
        m_lopriCmdQueue.removeFirst();
        newState = DScommandSentLow;
    }
    if (cmd == 0) {
        // nothing to do
        m_state = DSidle;               /* is necessary if command was interrupted earlier */
        return;
    }

    m_activeCmd = cmd;
    TRACE("in writeCommand: " + cmd->m_cmdString);

    const char* str = cmd->m_cmdString;
    writeStdin(const_cast<char*>(str), cmd->m_cmdString.length());

    // write also to log file
    if (m_logFile.isOpen()) {
        m_logFile.writeBlock(str, cmd->m_cmdString.length());
        m_logFile.flush();
    }

    m_state = newState;
}

void DebuggerDriver::flushLoPriQueue()
{
    while (!m_lopriCmdQueue.isEmpty()) {
        delete m_lopriCmdQueue.take(0);
    }
}

void DebuggerDriver::flushHiPriQueue()
{
    CmdQueueItem* cmd;
    while ((cmd = m_hipriCmdQueue.dequeue()) != 0) {
        delete cmd;
    }
}

void DebuggerDriver::flushCommands(bool hipriOnly)
{
    flushHiPriQueue();
    if (!hipriOnly) {
        flushLoPriQueue();
    }
}

void DebuggerDriver::slotCommandRead(KProcess*)
{
    TRACE(__PRETTY_FUNCTION__);

    // there must be an active command which is not yet commited
    ASSERT(m_state == DScommandSent || m_state == DScommandSentLow);
    ASSERT(m_activeCmd != 0);
    ASSERT(!m_activeCmd->m_committed);

    // commit the command
    m_activeCmd->m_committed = true;

    // now the debugger is officially working on the command
    m_state = m_state == DScommandSent ? DSrunning : DSrunningLow;

    // set the flag that reflects whether the program is really running
    switch (m_activeCmd->m_cmd) {
    case DCrun: case DCcont: case DCnext: case DCstep: case DCfinish: case DCuntil:
        emit inferiorRunning();
        break;
    default:
        break;
    }

    // re-receive delayed output
    if (m_delayedOutput.current() != 0) {
        DelayedStr* delayed;
        while ((delayed = m_delayedOutput.dequeue()) != 0) {
            const char* str = delayed->data();
            slotReceiveOutput(0, const_cast<char*>(str), delayed->length());
            delete delayed;
        }
    }
}

void DebuggerDriver::slotReceiveOutput(KProcess*, char* buffer, int buflen)
{
    /*
     * The debugger should be running (processing a command) at this point.
     * If it is not, it is still idle because we haven't received the
     * wroteStdin signal yet, in which case there must be an active command
     * which is not commited.
     */
    if (m_state == DScommandSent || m_state == DScommandSentLow) {
        ASSERT(m_activeCmd != 0);
        ASSERT(!m_activeCmd->m_committed);
        /*
         * We received output before we got signal wroteStdin. Collect this
         * output, it will be re-sent by commandRead when it gets the
         * acknowledgment for the uncommitted command.
         */
        m_delayedOutput.enqueue(new DelayedStr(buffer, buflen+1));
        return;
    }
    // write to log file (do not log delayed output - it would appear twice)
    if (m_logFile.isOpen()) {
        m_logFile.writeBlock(buffer, buflen);
        m_logFile.flush();
    }
    
    /*
     * gdb sometimes produces stray output while it's idle. This happens if
     * it receives a signal, most prominently a SIGCONT after a SIGTSTP:
     * The user haltet kdbg with Ctrl-Z, then continues it with "fg", which
     * also continues gdb, which repeats the prompt!
     */
    if (m_activeCmd == 0 && m_state != DSinterrupted) {
        // ignore the output
        TRACE("ignoring stray output: " + DelayedStr(buffer, buflen+1));
        return;
    }
    ASSERT(m_state == DSrunning || m_state == DSrunningLow || m_state == DSinterrupted);
    ASSERT(m_activeCmd != 0 || m_state == DSinterrupted);

    // collect output until next prompt string is found
    
    // accumulate it
    if (m_outputLen + buflen >= m_outputAlloc) {
        /*
         * Must enlarge m_output: double it. Note: That particular
         * sequence of commandes here ensures exception safety.
         */
        int newSize = m_outputAlloc * 2;
        char* newBuf = new char[newSize];
        memcpy(newBuf, m_output, m_outputLen);
        delete[] m_output;
        m_output = newBuf;
        m_outputAlloc = newSize;
    }
    memcpy(m_output+m_outputLen, buffer, buflen);
    m_outputLen += buflen;
    m_output[m_outputLen] = '\0';

    /*
     * If there's a prompt string in the collected output, it must be at
     * the very end. In order to quickly find out whether there is a prompt
     * string, we check whether the last character of m_output is identical
     * to the last character of the prompt string. Only if it is, we check
     * for the full prompt string.
     * 
     * Note: Using the regular expression here is most expensive, because
     * it translates m_output to a QString each time.
     * 
     * Note: It could nevertheless happen that a character sequence that is
     * equal to the prompt string appears at the end of the output,
     * although it is very, very unlikely (namely as part of a string that
     * lingered in gdb's output buffer due to some timing/heavy load
     * conditions for a very long time such that that buffer overflowed
     * exactly at the end of the prompt string look-a-like).
     */
    int promptStart = -1;
    if (m_output[m_outputLen-1] == m_promptLastChar &&
        m_outputLen >= m_promptMinLen)
    {
        // this is a candidate for a prompt at the end,
        // now see if there really is
        if (m_prompt[0] != '\0') {
            if (strncmp(m_output+m_outputLen-m_promptMinLen,
                        m_prompt, m_promptMinLen) == 0)
            {
                promptStart = m_outputLen-m_promptMinLen;
            }
        } else {
            QString output = QString::fromLatin1(m_output, m_outputLen);
#if QT_VERSION >= 300
            promptStart = m_promptRE.search(output);
#else
            promptStart = m_promptRE.match(output);
#endif
        }
    }
    if (promptStart >= 0)
    {
        // found prompt!

        // terminate output before the prompt
        m_output[promptStart] = '\0';

        /*
         * We've got output for the active command. But if it was
         * interrupted, ignore it.
         */
        if (m_state != DSinterrupted) {
            /*
             * m_state shouldn't be DSidle while we are parsing the output
             * so that all commands produced by parse() go into the queue
             * instead of being written to gdb immediately.
             */
            ASSERT(m_state != DSidle);
            CmdQueueItem* cmd = m_activeCmd;
            m_activeCmd = 0;
            commandFinished(cmd);
            delete cmd;
        }

        // empty buffer
        m_outputLen = 0;
        *m_output = '\0';
        // also clear delayed output if interrupted
        if (m_state == DSinterrupted) {
            DelayedStr* delayed;
            while ((delayed = m_delayedOutput.dequeue()) != 0) {
                delete delayed;
            }
        }

        /*
         * We parsed some output successfully. Unless there's more delayed
         * output, the debugger must be idle now, so send down the next
         * command.
         */
        if (m_delayedOutput.current() == 0) {
            if (m_hipriCmdQueue.isEmpty() && m_lopriCmdQueue.isEmpty()) {
                // no pending commands
                m_state = DSidle;
                emit enterIdleState();
            } else {
                writeCommand();
            }
        }
    }
}

void DebuggerDriver::dequeueCmdByVar(VarTree* var)
{
    if (var == 0)
        return;

    /*
     * Check the low-priority queue: We start at the back end, but skip the
     * last element for now. The reason is that if we delete an element the
     * current element is stepped to the next one - except if it's on the
     * last: then it's stepped to the previous element. By checking the
     * last element separately we avoid that special case.
     */
    CmdQueueItem* cmd = m_lopriCmdQueue.last();
    while ((cmd = m_lopriCmdQueue.prev()) != 0) {
        if (cmd->m_expr != 0 && var->isAncestorEq(cmd->m_expr)) {
            // this is indeed a critical command; delete it
            TRACE("removing critical lopri-cmd: " + cmd->m_cmdString);
            m_lopriCmdQueue.remove();   /* steps to next element */
        }
    }
    cmd = m_lopriCmdQueue.last();
    if (cmd != 0) {
        if (cmd->m_expr != 0 && var->isAncestorEq(cmd->m_expr)) {
            TRACE("removing critical lopri-cmd: " + cmd->m_cmdString);
            m_lopriCmdQueue.remove();   /* steps to next element */
        }
    }
}


QString DebuggerDriver::editableValue(VarTree* value)
{
    // by default, let the user edit what is visible
    return value->value();
}


StackFrame::~StackFrame()
{
    delete var;
}


DbgAddr::DbgAddr(const QString& aa) :
        a(aa)
{
    cleanAddr();
}

/*
 * We strip off the leading 0x and any leading zeros.
 */
void DbgAddr::cleanAddr()
{
    if (a.isEmpty())
        return;

    while (a[0] == '0' || a[0] == 'x') {
        a.remove(0, 1);
    }
}

void DbgAddr::operator=(const QString& aa)
{
    a = aa;
    fnoffs = QString();
    cleanAddr();
}

/* Re-attach 0x in front of the address */
QString DbgAddr::asString() const
{
    if (a.isEmpty())
        return QString();
    else
        return "0x" + a;
}

bool operator==(const DbgAddr& a1, const DbgAddr& a2)
{
    return QString::compare(a1.a, a2.a) == 0;
}

bool operator>(const DbgAddr& a1, const DbgAddr& a2)
{
    if (a1.a.length() > a2.a.length())
        return true;
    if (a1.a.length() < a2.a.length())
        return false;
    return QString::compare(a1.a, a2.a) > 0;
}


Breakpoint::Breakpoint() :
        id(0),
        type(breakpoint),
        temporary(false),
        enabled(true),
        ignoreCount(0),
        hitCount(0),
        lineNo(0)
{ }

#include "dbgdriver.moc"