Programs.cpp

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/* Programs.cpp

   Copyright (C)  David C. J. Matthews 2004  dm at prolingua.co.uk

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   Or, point your browser to http://www.gnu.org/copyleft/gpl.html

*/

#include "Programs.h"
#include "Ingredients.h"
#include "Root.h"
#include "BaseClasses.h"
#include "ParseNode.h"
#include "ASN1Codes.h"
#include "Engine.h"
#include "Logging.h"
#include "freemheg.h"

#include <sys/timeb.h>
#ifdef __FreeBSD__ 
#include <sys/time.h> 
#else
#include <time.h>
#endif

#include "../../config.h"

/*
 * Resident programs are subroutines to provide various string and date functions
 * but also interface to surrounding tuner.  They are defined in the UK MHEG profile.
 * As with many of the more abstruse aspects of MHEG they are not all used in any
 * applications I've seen so I haven't implemented them.
 */


MHProgram::MHProgram()
{
    m_fInitiallyAvailable = true; // Default true
}

void MHProgram::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHIngredient::Initialise(p, engine);
    p->GetNamedArg(C_NAME)->GetArgN(0)->GetStringValue(m_Name); // Program name
    MHParseNode *pAvail = p->GetNamedArg(C_INITIALLY_AVAILABLE);
    if (pAvail) m_fInitiallyAvailable = pAvail->GetArgN(0)->GetBoolValue();
    // The MHEG Standard says that InitiallyAvailable is mandatory and should be false.
    // That doesn't seem to be the case in some MHEG programs so we force it here.
    m_fInitiallyActive = false;
}

void MHProgram::PrintMe(FILE *fd, int nTabs) const
{
    MHIngredient::PrintMe(fd, nTabs);
    PrintTabs(fd, nTabs); fprintf(fd, ":Name "); m_Name.PrintMe(fd, 0); fprintf(fd, "\n");
    if (! m_fInitiallyAvailable) { PrintTabs(fd, nTabs); fprintf(fd, ":InitiallyAvailable false"); fprintf(fd, "\n"); }
}

// Set "running" and generate an IsRunning event.
void MHProgram::Activation(MHEngine *engine)
{
    if (m_fRunning) return;
    MHIngredient::Activation(engine);
    m_fRunning = true;
    engine->EventTriggered(this, EventIsRunning);
}

// This can be called if we change scene while a forked program is running
void MHProgram::Deactivation(MHEngine *engine)
{
    if (! m_fRunning) return;
    // TODO: Stop the forked program.
    MHIngredient::Deactivation(engine);
}

void MHResidentProgram::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs); fprintf(fd, "{:ResidentPrg ");
    MHProgram::PrintMe(fd, nTabs+1);
    PrintTabs(fd, nTabs); fprintf(fd, "}\n");
}

static void SetSuccessFlag(const MHObjectRef &success, bool result, MHEngine *engine)
{
    engine->FindObject(success)->SetVariableValue(result);
}

// Return an integer value.  May throw an exception if it isn't the correct type.
static int GetInt(MHParameter *parm, MHEngine *engine)
{
    MHUnion un;
    un.GetValueFrom(*parm, engine);
    un.CheckType(MHUnion::U_Int);
    return un.m_nIntVal;
}

// Extract a string value.
static void GetString(MHParameter *parm, MHOctetString &str, MHEngine *engine)
{
    MHUnion un;
    un.GetValueFrom(*parm, engine);
    un.CheckType(MHUnion::U_String);
    str.Copy(un.m_StrVal);
}

void MHResidentProgram::CallProgram(bool fIsFork, const MHObjectRef &success, const MHSequence<MHParameter *> &args, MHEngine *engine)
{
    if (! m_fAvailable) Preparation(engine);
//  if (m_fRunning) return; // Strictly speaking there should be only one instance of a program running at a time. 
    Activation(engine);
    MHLOG(MHLogDetail, QString("Calling program %1").arg(m_Name.Printable()));
    try {
        // Run the code.
        if (m_Name.Equal("GCD")) { // GetCurrentDate - returns local time.
            if (args.Size() == 2) {
                struct timeb timebuffer;
#ifdef HAVE_FTIME
                ftime(&timebuffer);
#else
    #ifdef HAVE_GETTIMEOFDAY
                struct timeval   time;
                struct timezone  zone;

                if (gettimeofday(&time,&zone) == -1)
                    MHLOG(MHLogDetail, QString("gettimeofday() failed"));
                timebuffer.time     = time.tv_sec;
                timebuffer.timezone = zone.tz_minuteswest;
                timebuffer.dstflag  = zone.tz_dsttime;
    #else
        #error Configuration error? No ftime() or gettimeofday()?
    #endif
#endif
                // Adjust the time to local.  TODO: Check this.
                timebuffer.time -= timebuffer.timezone * 60;
                // Time as seconds since midnight.
                int nTimeAsSecs = timebuffer.time % (24 * 60 * 60);
                // Modified Julian date as number of days since 17th November 1858.
                // 1st Jan 1970 was date 40587.
                int nModJulianDate = 40587 + timebuffer.time / (24 * 60 * 60);

                engine->FindObject(*(args.GetAt(0)->GetReference()))->SetVariableValue(nModJulianDate);
                engine->FindObject(*(args.GetAt(1)->GetReference()))->SetVariableValue(nTimeAsSecs);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("FDa")) { // FormatDate
            if (args.Size() == 4) {
                // This is a bit like strftime but not quite.
                MHOctetString format;
                GetString(args.GetAt(0), format, engine);
                int date = GetInt(args.GetAt(1), engine); // As produced in GCD
                int time = GetInt(args.GetAt(2), engine);
                // Convert to a Unix date (secs since 1st Jan 1970) but adjusted for time zone.
                time_t timet = (date - 40587) * (24 * 60 * 60) + time;
                struct tm *timeStr = gmtime(&timet);
                MHOctetString result;
                for (int i = 0; i < format.Size(); i++) {
                    unsigned char ch = format.GetAt(i);
                    char buffer[5]; // Largest text is 4 chars for a year + null terminator
                    if (ch == '%') {
                        i++;
                        if (i == format.Size()) break;
                        ch = format.GetAt(i);
                        buffer[0] = 0;
                        switch (ch)
                        {
                        case 'Y': sprintf(buffer, "%04d", timeStr->tm_year + 1900); break;
                        case 'y': sprintf(buffer, "%02d", timeStr->tm_year % 100); break;
                        case 'X': sprintf(buffer, "%02d", timeStr->tm_mon+1); break;
                        case 'x': sprintf(buffer, "%1d", timeStr->tm_mon+1); break;
                        case 'D': sprintf(buffer, "%02d", timeStr->tm_mday); break;
                        case 'd': sprintf(buffer, "%1d", timeStr->tm_mday); break;
                        case 'H': sprintf(buffer, "%02d", timeStr->tm_hour); break;
                        case 'h': sprintf(buffer, "%1d", timeStr->tm_hour); break;
                        case 'I':
                            if (timeStr->tm_hour == 12 || timeStr->tm_hour == 0) strcpy(buffer, "12");
                            else sprintf(buffer, "%02d", timeStr->tm_hour % 12);
                            break;
                        case 'i':
                            if (timeStr->tm_hour == 12 || timeStr->tm_hour == 0) strcpy(buffer, "12");
                            else sprintf(buffer, "%1d", timeStr->tm_hour % 12);
                            break;
                        case 'M': sprintf(buffer, "%02d", timeStr->tm_min); break;
                        case 'm': sprintf(buffer, "%1d", timeStr->tm_min); break;
                        case 'S': sprintf(buffer, "%02d", timeStr->tm_sec); break;
                        case 's': sprintf(buffer, "%1d", timeStr->tm_sec); break;
                            // TODO: These really should be localised.
                        case 'A': if (timeStr->tm_hour < 12) strcpy(buffer, "AM"); else strcpy(buffer, "PM"); break;
                        case 'a': if (timeStr->tm_hour < 12) strcpy(buffer, "am"); else strcpy(buffer, "pm"); break;
                        default: buffer[0] = ch; buffer[1] = 0;
                        }
                        result.Append(buffer);
                    }
                    else result.Append(MHOctetString(&ch, 1));
                }
                MHParameter *pResString = args.GetAt(3);
                engine->FindObject(*(pResString->GetReference()))->SetVariableValue(result);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("GDW")) { // GetDayOfWeek - returns the day of week that the date occurred on.
            if (args.Size() == 2) {
                int date = GetInt(args.GetAt(0), engine); // Date as produced in GCD
                // Convert to a Unix date (secs since 1st Jan 1970) but adjusted for time zone.
                time_t timet = (date - 40587) * (24 * 60 * 60);
                struct tm *timeStr = gmtime(&timet);
                // 0 => Sunday, 1 => Monday etc.
                engine->FindObject(*(args.GetAt(1)->GetReference()))->SetVariableValue(timeStr->tm_wday);
                SetSuccessFlag(success, true, engine);
            } else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("Rnd")) { // Random
            if (args.Size() == 2) {
                int nLimit = GetInt(args.GetAt(0), engine);
                MHParameter *pResInt = args.GetAt(1);
                srand((unsigned)time( NULL ));
                engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(rand() % nLimit +1);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("CTC")) { // CastToContentRef
            // Converts a string to a ContentRef.
            if (args.Size() == 2) {
                MHOctetString string;
                GetString(args.GetAt(0), string, engine);
                MHContentRef result;
                result.m_ContentRef.Copy(string);
                engine->FindObject(*(args.GetAt(1)->GetReference()))->SetVariableValue(result);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("CTO")) { // CastToObjectRef
            // Converts a string and an integer to an ObjectRef.
            if (args.Size() == 3) {
                MHObjectRef result;
                GetString(args.GetAt(0), result.m_GroupId, engine);
                result.m_nObjectNo = GetInt(args.GetAt(1), engine);
                engine->FindObject(*(args.GetAt(2)->GetReference()))->SetVariableValue(result);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("GSL")) { // GetStringLength
            if (args.Size() == 2) {
                // Find a substring within a string and return an index to the position.
                MHOctetString string;
                GetString(args.GetAt(0), string, engine);
                MHParameter *pResInt = args.GetAt(1);
                SetSuccessFlag(success, true, engine);
                engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(string.Size());
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("GSS")) { // GetSubString
            if (args.Size() == 4) { // Extract a sub-string from a string.
                MHOctetString string;
                GetString(args.GetAt(0), string, engine);
                int nBeginExtract = GetInt(args.GetAt(1), engine);
                int nEndExtract = GetInt(args.GetAt(2), engine);
                if (nBeginExtract < 1) nBeginExtract = 1;
                if (nBeginExtract > string.Size()) nBeginExtract = string.Size();
                if (nEndExtract < 1) nEndExtract = 1;
                if (nEndExtract > string.Size()) nEndExtract = string.Size();
                MHParameter *pResString = args.GetAt(3);
                // Returns beginExtract to endExtract inclusive.
                engine->FindObject(*(pResString->GetReference()))->SetVariableValue(
                    MHOctetString(string, nBeginExtract-1, nEndExtract-nBeginExtract+1));
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("SSS")) { // SearchSubString
            if (args.Size() == 4) {
                // Find a substring within a string and return an index to the position.
                MHOctetString string, searchString;
                GetString(args.GetAt(0), string, engine);
                int nStart = GetInt(args.GetAt(1), engine);
                if (nStart < 1) nStart = 1;
                GetString(args.GetAt(2), searchString, engine);
                // Strings are indexed from one.
                int nPos;
                for (nPos = nStart-1; nPos <= string.Size() - searchString.Size(); nPos++) {
                    int i;
                    for (i = 0; i < searchString.Size(); i++) {
                        if (searchString.GetAt(i) != string.GetAt(i+nPos)) break;
                    }
                    if (i == searchString.Size()) break; // Found a match.
                }
                // Set the result.
                MHParameter *pResInt = args.GetAt(3);
                SetSuccessFlag(success, true, engine); // Set this first.
                if (nPos <= string.Size() - searchString.Size()) { // Found
                    // Set the index to the position of the string, counting from 1.
                    engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(nPos+1);
                }
                else { // Not found.  Set the result index to -1
                    engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(-1);
                }
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("SES")) { // SearchAndExtractSubString
            if (args.Size() == 5) {
                // Find a substring within a string and return an index to the position
                // and the prefix to the substring.
                MHOctetString string, searchString;
                GetString(args.GetAt(0), string, engine);
                int nStart = GetInt(args.GetAt(1), engine);
                if (nStart < 1) nStart = 1;
                GetString(args.GetAt(2), searchString, engine);
                // Strings are indexed from one.
                int nPos;
                for (nPos = nStart-1; nPos <= string.Size() - searchString.Size(); nPos++) {
                    int i;
                    for (i = 0; i < searchString.Size(); i++) {
                        if (searchString.GetAt(i) != string.GetAt(i+nPos)) break; // Doesn't match
                    }
                    if (i == searchString.Size()) break; // Found a match.
                }
                // Set the results.
                MHParameter *pResString = args.GetAt(3);
                MHParameter *pResInt = args.GetAt(4);
                SetSuccessFlag(success, true, engine); // Set this first.
                if (nPos <= string.Size() - searchString.Size()) { // Found
                    // Set the index to the position AFTER the string, counting from 1.
                    engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(nPos+1+searchString.Size());
                    // Return the sequence from nStart-1 of length nPos-nStart+1
                    MHOctetString resultString(string, nStart-1, nPos-nStart+1);
                    engine->FindObject(*(pResString->GetReference()))->SetVariableValue(resultString);
                }
                else { // Not found.  Set the result string to empty and the result index to -1
                    engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(-1);
                    engine->FindObject(*(pResString->GetReference()))->SetVariableValue(MHOctetString(""));
                }
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("GSI")) { // SI_GetServiceIndex
            // Returns an index indicating the service
            if (args.Size() == 2) {
                MHOctetString string;
                GetString(args.GetAt(0), string, engine);
                MHParameter *pResInt = args.GetAt(1);
                // The format of the service is dvb://netID.[transPortID].serviceID
                // where the IDs are in hex.
                // or rec://svc/lcn/N where N is the "logical channel number" i.e. the Freeview channel.
                QString str = QString::fromUtf8((const char *)string.Bytes(), string.Size());
                int nResult = engine->GetContext()->GetChannelIndex(str);
                engine->FindObject(*(pResInt->GetReference()))->SetVariableValue(nResult);
                MHLOG(MHLogDetail, QString("Get service index for %1 - result %2").arg(string.Printable()).arg(nResult));
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("TIn")) { // SI_TuneIndex - Fork not allowed
            // Tunes to an index returned by GSI
            if (args.Size() == 1) {
                int nChannel = GetInt(args.GetAt(0), engine);
                bool res = engine->GetContext()->TuneTo(nChannel);
                SetSuccessFlag(success, res, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }
        else if (m_Name.Equal("TII")) { // SI_TuneIndexInfo
            // Indicates whether to perform a subsequent TIn quietly or normally. 
            MHERROR("SI_TuneIndexInfo ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("BSI")) { // SI_GetBasicSI
            // Returns basic SI information about the service indicated by an index
            // returned by GSI.
            // Returns networkID, origNetworkID, transportStreamID, serviceID
            if (args.Size() == 5) {
                int channelId = GetInt(args.GetAt(0), engine);
                int netId, origNetId, transportId, serviceId;
                // Look the information up in the database.
                bool res = engine->GetContext()->GetServiceInfo(channelId, netId, origNetId,
                                transportId, serviceId);
                if (res)
                {
                    engine->FindObject(*(args.GetAt(1)->GetReference()))->SetVariableValue(netId);
                    engine->FindObject(*(args.GetAt(2)->GetReference()))->SetVariableValue(origNetId);
                    engine->FindObject(*(args.GetAt(3)->GetReference()))->SetVariableValue(transportId);
                    engine->FindObject(*(args.GetAt(4)->GetReference()))->SetVariableValue(serviceId);
                }
                SetSuccessFlag(success, res, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }
        else if (m_Name.Equal("GBI")) { // GetBootInfo
            // Gets the NB_info field.
            MHERROR("GetBootInfo ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("CCR")) { // CheckContentRef
            // Sees if an item with a particular content reference is available
            // in the carousel.  This looks like it should block until the file
            // is available.  The profile recommends that this should be forked
            // rather than called.
            if (args.Size() == 3) {
                MHUnion un;
                un.GetValueFrom(*(args.GetAt(0)), engine);
                un.CheckType(MHUnion::U_ContentRef);
                MHContentRef fileName;
                fileName.Copy(un.m_ContentRefVal);
                QString csPath = engine->GetPathName(fileName.m_ContentRef);
                bool result = false;
                QByteArray text;
                // Try to load the object.
                if (! csPath.isEmpty())
                    result = engine->GetContext()->GetCarouselData(csPath, text);
                // Set the result variable.
                MHParameter *pResFlag = args.GetAt(1);
                engine->FindObject(*(pResFlag->GetReference()))->SetVariableValue(result);
                MHParameter *pResCR = args.GetAt(2);
                // Copy the file name to the resulting content ref.
                engine->FindObject(*(pResCR->GetReference()))->SetVariableValue(fileName);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }
        else if (m_Name.Equal("CGR")) { // CheckGroupIDRef
            // Sees if an application or scene with a particular group id
            // is available in the carousel.
            MHERROR("CheckGroupIDRef ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("VTG")) { // VideoToGraphics
            // Video to graphics transformation.
            MHERROR("VideoToGraphics ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("SWA")) { // SetWidescreenAlignment
            // Sets either LetterBox or Centre-cut-out mode.
            // Seems to be concerned with aligning a 4:3 scene with an underlying 16:9 video
            MHERROR("SetWidescreenAlignment ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("GDA")) { // GetDisplayAspectRatio
            // Returns the aspcet ratio.  4:3 => 1, 16:9 => 2
            MHERROR("GetDisplayAspectRatio ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("CIS")) { // CI_SendMessage
            // Sends a message to a DVB CI application
            MHERROR("CI_SendMessage ResidentProgram is not implemented");
        }
        else if (m_Name.Equal("SSM")) { // SetSubtitleMode
            // Enable or disable subtitles in addition to MHEG.
            MHERROR("SetSubtitleMode ResidentProgram is not implemented");
        }

        else if (m_Name.Equal("WAI")) { // WhoAmI
            // Return a concatenation of the strings we respond to in
            // GetEngineSupport(UKEngineProfile(X))
            if (args.Size() == 1)
            {
                MHOctetString result;
                result.Copy(engine->MHEGEngineProviderIdString);
                result.Append(" ");
                result.Append(engine->GetContext()->GetReceiverId());
                result.Append(" ");
                result.Append(engine->GetContext()->GetDSMCCId());
                engine->FindObject(*(args.GetAt(0)->GetReference()))->SetVariableValue(result);
                SetSuccessFlag(success, true, engine);
            }
            else SetSuccessFlag(success, false, engine);
        }

        else if (m_Name.Equal("DBG")) { // Debug - optional
            QString message = "DEBUG: ";
            for (int i = 0; i < args.Size(); i++) {
                MHUnion un;
                un.GetValueFrom(*(args.GetAt(i)), engine);
                switch (un.m_Type) {
                case MHUnion::U_Int:
                    message.append(QString("%1").arg(un.m_nIntVal));
                    break;
                case MHParameter::P_Bool:
                    message.append(un.m_fBoolVal ? "True" : "False");
                    break;
                case MHParameter::P_String:
                    message.append(QString::fromUtf8((const char *)un.m_StrVal.Bytes(), un.m_StrVal.Size()));
                    break;
                case MHParameter::P_ObjRef:
                    message.append(un.m_ObjRefVal.Printable());
                    break;
                case MHParameter::P_ContentRef:
                    message.append(un.m_ContentRefVal.Printable());
                    break;
                case MHParameter::P_Null:
                    break;
                }
            }
            MHLOG(MHLogNotifications, message);
        }

        else {
            MHERROR(QString("Unknown ResidentProgram %1").arg(m_Name.Printable()));
        }
    }
    catch (char const *) {
        // If something went wrong set the succeeded flag to false
        SetSuccessFlag(success, false, engine);
        // And continue on.  In particular we need to deactivate.
    }
    Deactivation(engine);
    // At the moment we always treat Fork as Call.  If we do get a Fork we should signal that we're done. 
    if (fIsFork) engine->EventTriggered(this, EventAsyncStopped);
}

MHRemoteProgram::MHRemoteProgram()
{

}

MHRemoteProgram::~MHRemoteProgram()
{

}

void MHRemoteProgram::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHProgram::Initialise(p, engine);
    //
}

void MHRemoteProgram::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs); fprintf(fd, "{:RemotePrg");
    MHProgram::PrintMe(fd, nTabs+1);
    fprintf(fd, "****TODO\n");
    PrintTabs(fd, nTabs); fprintf(fd, "}\n");
}

MHInterChgProgram::MHInterChgProgram()
{

}

MHInterChgProgram::~MHInterChgProgram()
{

}

void MHInterChgProgram::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHProgram::Initialise(p, engine);
    //
}

void MHInterChgProgram::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs); fprintf(fd, "{:InterchgPrg");
    MHProgram::PrintMe(fd, nTabs+1);
    fprintf(fd, "****TODO\n");
    PrintTabs(fd, nTabs); fprintf(fd, "}\n");
}

// Actions.
void MHCall::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHElemAction::Initialise(p, engine); // Target
    m_Succeeded.Initialise(p->GetArgN(1), engine); // Call/fork succeeded flag
    // Arguments.
    MHParseNode *args = p->GetArgN(2);
    for (int i = 0; i < args->GetSeqCount(); i++) {
        MHParameter *pParm = new MHParameter;
        m_Parameters.Append(pParm);
        pParm->Initialise(args->GetSeqN(i), engine);
    }
}

void MHCall::PrintArgs(FILE *fd, int nTabs) const
{
    m_Succeeded.PrintMe(fd, nTabs);
    fprintf(fd, " ( ");
    for (int i = 0; i < m_Parameters.Size(); i++) m_Parameters.GetAt(i)->PrintMe(fd, 0);
    fprintf(fd, " )\n");
}

void MHCall::Perform(MHEngine *engine)
{
    // Output parameters are handled by IndirectRefs so we don't evaluate the parameters here.
    Target(engine)->CallProgram(m_fIsFork, m_Succeeded, m_Parameters, engine);
}

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