lscript_byteconvert.h

Go to the documentation of this file.

// data shared between compiler/assembler
// used to convert data between byte stream and outside data types

#ifndef LL_LSCRIPT_BYTECONVERT_H
#define LL_LSCRIPT_BYTECONVERT_H

#include "stdtypes.h"
#include "v3math.h"
#include "llquaternion.h"
#include "lscript_byteformat.h"
#include "lluuid.h"

void reset_hp_to_safe_spot(const U8 *buffer);

// remember that LScript byte stream is BigEndian
void set_fault(const U8 *stream, LSCRIPTRunTimeFaults fault);

inline S32 bytestream2integer(const U8 *stream, S32 &offset)
{
        stream += offset;
        offset += 4;
        return (*stream<<24) | (*(stream + 1)<<16) | (*(stream + 2)<<8) | *(stream + 3);
}

inline U32 bytestream2unsigned_integer(const U8 *stream, S32 &offset)
{
        stream += offset;
        offset += 4;
        return (*stream<<24) | (*(stream + 1)<<16) | (*(stream + 2)<<8) | *(stream + 3);
}

inline U64 bytestream2u64(const U8 *stream, S32 &offset)
{
        stream += offset;
        offset += 8;
        return ((U64)(*stream)<<56)| ((U64)(*(stream + 1))<<48) | ((U64)(*(stream + 2))<<40) | ((U64)(*(stream + 3))<<32) | 
                   ((U64)(*(stream + 4))<<24) | ((U64)(*(stream + 5))<<16) | ((U64)(*(stream + 6))<<8) | (U64)(*(stream + 7));
}

inline void integer2bytestream(U8 *stream, S32 &offset, S32 integer)
{
        stream += offset;
        offset += 4;
        *(stream)       = (integer >> 24);
        *(stream + 1)   = (integer >> 16) & 0xff;
        *(stream + 2)   = (integer >> 8) & 0xff;
        *(stream + 3)   = (integer) & 0xff;
}

inline void unsigned_integer2bytestream(U8 *stream, S32 &offset, U32 integer)
{
        stream += offset;
        offset += 4;
        *(stream)       = (integer >> 24);
        *(stream + 1)   = (integer >> 16) & 0xff;
        *(stream + 2)   = (integer >> 8) & 0xff;
        *(stream + 3)   = (integer) & 0xff;
}
inline void u642bytestream(U8 *stream, S32 &offset, U64 integer)
{
        stream += offset;
        offset += 8;
        *(stream)               = (U8)(integer >> 56);
        *(stream + 1)   = (U8)((integer >> 48) & 0xff);
        *(stream + 2)   = (U8)((integer >> 40) & 0xff);
        *(stream + 3)   = (U8)((integer >> 32) & 0xff);
        *(stream + 4)   = (U8)((integer >> 24) & 0xff);
        *(stream + 5)   = (U8)((integer >> 16) & 0xff);
        *(stream + 6)   = (U8)((integer >> 8) & 0xff);
        *(stream + 7)   = (U8)((integer) & 0xff);
}

inline S16 bytestream2s16(const U8 *stream, S32 &offset)
{
        stream += offset;
        offset += 2;
        return (*stream<<8) | *(stream + 1);
}

inline void s162bytestream(U8 *stream, S32 &offset, S16 integer)
{
        stream += offset;
        offset += 2;
        *(stream)               = (integer >> 8);
        *(stream + 1)   = (integer) & 0xff;
}

inline U16 bytestream2u16(const U8 *stream, S32 &offset)
{
        stream += offset;
        offset += 2;
        return (*stream<<8) | *(stream + 1);
}

inline void u162bytestream(U8 *stream, S32 &offset, U16 integer)
{
        stream += offset;
        offset += 2;
        *(stream)               = (integer >> 8);
        *(stream + 1)   = (integer) & 0xff;
}

inline F32 bytestream2float(const U8 *stream, S32 &offset)
{
        S32 value = bytestream2integer(stream, offset);
        F32 fpvalue = *(F32 *)&value;
        if (!llfinite(fpvalue))
        {
                fpvalue = 0;
                set_fault(stream, LSRF_MATH);
        }
        return fpvalue;
}

inline void float2bytestream(U8 *stream, S32 &offset, F32 floatingpoint)
{
        S32 value = *(S32 *)&floatingpoint;
        integer2bytestream(stream, offset, value);
}

inline void bytestream_int2float(U8 *stream, S32 &offset)
{
        S32 value = bytestream2integer(stream, offset);
        offset -= 4;
        F32 fpvalue = (F32)value;
        if (!llfinite(fpvalue))
        {
                fpvalue = 0;
                set_fault(stream, LSRF_MATH);
        }
        float2bytestream(stream, offset, fpvalue);
}

// Returns true on success, return false and clip copy on buffer overflow
inline bool bytestream2char(char *buffer, const U8 *stream, S32 &offset, S32 buffsize)
{
        S32 source_len = strlen( (const char *)stream+offset );
        S32 copy_len = buffsize - 1;
        if( copy_len > source_len )
        {
                copy_len = source_len;
        }

        // strncpy without \0 padding overhead
        memcpy( buffer, stream+offset, copy_len );
        buffer[copy_len] = 0;

        offset += source_len + 1; // advance past source string, include terminating '\0'

        return source_len < buffsize;
}

inline void char2bytestream(U8 *stream, S32 &offset, const char *buffer)
{
        while ((*(stream + offset++) = *buffer++))
                ;
}

inline U8 bytestream2byte(const U8 *stream, S32 &offset)
{
        return *(stream + offset++);
}

inline void byte2bytestream(U8 *stream, S32 &offset, U8 byte)
{
        *(stream + offset++) = byte;
}

inline void bytestream2bytestream(U8 *dest, S32 &dest_offset, const U8 *src, S32 &src_offset, S32 count)
{
        while (count)
        {
                (*(dest + dest_offset++)) = (*(src + src_offset++));
                count--;
        }
}

inline void uuid2bytestream(U8 *stream, S32 &offset, const LLUUID &uuid)
{
        S32 i;
        for (i = 0; i < UUID_BYTES; i++)
        {
                *(stream + offset++) = uuid.mData[i];
        }
}

inline void bytestream2uuid(U8 *stream, S32 &offset, LLUUID &uuid)
{
        S32 i;
        for (i = 0; i < UUID_BYTES; i++)
        {
                uuid.mData[i] = *(stream + offset++);
        }
}

// vectors and quaternions and encoded in backwards order to match the way in which they are stored on the stack
inline void bytestream2vector(LLVector3 &vector, const U8 *stream, S32 &offset)
{
        S32 value = bytestream2integer(stream, offset);
        vector.mV[VZ] = *(F32 *)&value;
        if (!llfinite(vector.mV[VZ]))
        {
                vector.mV[VZ] = 0;
                set_fault(stream, LSRF_MATH);
        }
        value = bytestream2integer(stream, offset);
        vector.mV[VY] = *(F32 *)&value;
        if (!llfinite(vector.mV[VY]))
        {
                vector.mV[VY] = 0;
                set_fault(stream, LSRF_MATH);
        }
        value = bytestream2integer(stream, offset);
        vector.mV[VX] = *(F32 *)&value;
        if (!llfinite(vector.mV[VX]))
        {
                vector.mV[VX] = 0;
                set_fault(stream, LSRF_MATH);
        }
}

inline void vector2bytestream(U8 *stream, S32 &offset, LLVector3 &vector)
{
        S32 value = *(S32 *)&vector.mV[VZ];
        integer2bytestream(stream, offset, value);
        value = *(S32 *)&vector.mV[VY];
        integer2bytestream(stream, offset, value);
        value = *(S32 *)&vector.mV[VX];
        integer2bytestream(stream, offset, value);
}

inline void bytestream2quaternion(LLQuaternion &quat, const U8 *stream, S32 &offset)
{
        S32 value = bytestream2integer(stream, offset);
        quat.mQ[VS] = *(F32 *)&value;
        if (!llfinite(quat.mQ[VS]))
        {
                quat.mQ[VS] = 0;
                set_fault(stream, LSRF_MATH);
        }
        value = bytestream2integer(stream, offset);
        quat.mQ[VZ] = *(F32 *)&value;
        if (!llfinite(quat.mQ[VZ]))
        {
                quat.mQ[VZ] = 0;
                set_fault(stream, LSRF_MATH);
        }
        value = bytestream2integer(stream, offset);
        quat.mQ[VY] = *(F32 *)&value;
        if (!llfinite(quat.mQ[VY]))
        {
                quat.mQ[VY] = 0;
                set_fault(stream, LSRF_MATH);
        }
        value = bytestream2integer(stream, offset);
        quat.mQ[VX] = *(F32 *)&value;
        if (!llfinite(quat.mQ[VX]))
        {
                quat.mQ[VX] = 0;
                set_fault(stream, LSRF_MATH);
        }
}

inline void quaternion2bytestream(U8 *stream, S32 &offset, LLQuaternion &quat)
{
        S32 value = *(S32 *)&quat.mQ[VS];
        integer2bytestream(stream, offset, value);
        value = *(S32 *)&quat.mQ[VZ];
        integer2bytestream(stream, offset, value);
        value = *(S32 *)&quat.mQ[VY];
        integer2bytestream(stream, offset, value);
        value = *(S32 *)&quat.mQ[VX];
        integer2bytestream(stream, offset, value);
}

inline S32 get_register(const U8 *stream, LSCRIPTRegisters reg)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        return bytestream2integer(stream, offset);
}

inline F32 get_register_fp(U8 *stream, LSCRIPTRegisters reg)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        F32 value = bytestream2float(stream, offset);
        if (!llfinite(value))
        {
                value = 0;
                set_fault(stream, LSRF_MATH);
        }
        return value;
}
inline U64 get_register_u64(U8 *stream, LSCRIPTRegisters reg)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        return bytestream2u64(stream, offset);
}

inline U64 get_event_register(U8 *stream, LSCRIPTRegisters reg, S32 major_version)
{
        if (major_version == 1)
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg];
                return (U64)bytestream2integer(stream, offset);
        }
        else if (major_version == 2)
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg + (LREG_NCE - LREG_CE)];
                return bytestream2u64(stream, offset);
        }
        else
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg];
                return (U64)bytestream2integer(stream, offset);
        }
}

inline void set_register(U8 *stream, LSCRIPTRegisters reg, S32 value)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        integer2bytestream(stream, offset, value);
}

inline void set_register_fp(U8 *stream, LSCRIPTRegisters reg, F32 value)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        float2bytestream(stream, offset, value);
}

inline void set_register_u64(U8 *stream, LSCRIPTRegisters reg, U64 value)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        u642bytestream(stream, offset, value);
}

inline void set_event_register(U8 *stream, LSCRIPTRegisters reg, U64 value, S32 major_version)
{
        if (major_version == 1)
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg];
                integer2bytestream(stream, offset, (S32)value);
        }
        else if (major_version == 2)
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg + (LREG_NCE - LREG_CE)];
                u642bytestream(stream, offset, value);
        }
        else
        {
                S32 offset = gLSCRIPTRegisterAddresses[reg];
                integer2bytestream(stream, offset, (S32)value);
        }
}


inline F32 add_register_fp(U8 *stream, LSCRIPTRegisters reg, F32 value)
{
        S32 offset = gLSCRIPTRegisterAddresses[reg];
        F32 newvalue = bytestream2float(stream, offset);
        newvalue += value;
        if (!llfinite(newvalue))
        {
                newvalue = 0;
                set_fault(stream, LSRF_MATH);
        }
        offset = gLSCRIPTRegisterAddresses[reg];
        float2bytestream(stream, offset, newvalue);
        return newvalue;
}

void lsa_print_heap(U8 *buffer);


inline void set_fault(const U8 *stream, LSCRIPTRunTimeFaults fault)
{
   S32 fr = get_register(stream, LREG_FR);
   // record the first error
   if (!fr)
   {
           if (  (fault == LSRF_HEAP_ERROR)
                   ||(fault == LSRF_STACK_HEAP_COLLISION)
                   ||(fault == LSRF_BOUND_CHECK_ERROR))
           {
                        reset_hp_to_safe_spot(stream);
//                  lsa_print_heap((U8 *)stream);
           }
       fr = LSCRIPTRunTimeFaultBits[fault];
       set_register((U8 *)stream, LREG_FR, fr);
   }
}

inline BOOL set_ip(U8 *stream, S32 ip)
{
        // Verify that the Instruction Pointer is in a valid
        // code area (between the Global Function Register
        // and Heap Register).
        S32 gfr = get_register(stream, LREG_GFR);
        if (ip == 0)
        {
                set_register(stream, LREG_IP, ip);
                return TRUE;
        }
        if (ip < gfr)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        S32 hr = get_register(stream, LREG_HR);
        if (ip >= hr)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        set_register(stream, LREG_IP, ip);
        return TRUE;
}

inline BOOL set_bp(U8 *stream, S32 bp)
{
        // Verify that the Base Pointer is in a valid
        // data area (between the Heap Pointer and
        // the Top of Memory, and below the
        // Stack Pointer).
        S32 hp = get_register(stream, LREG_HP);
        if (bp <= hp)
        {
                set_fault(stream, LSRF_STACK_HEAP_COLLISION);
                return FALSE;
        }
        S32 tm = get_register(stream, LREG_TM);
        if (bp >= tm)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        S32 sp = get_register(stream, LREG_SP);
        if (bp < sp)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        set_register(stream, LREG_BP, bp);
        return TRUE;
}

inline BOOL set_sp(U8 *stream, S32 sp)
{
        // Verify that the Stack Pointer is in a valid
        // data area (between the Heap Pointer and
        // the Top of Memory).
        S32 hp = get_register(stream, LREG_HP);
        if (sp <= hp)
        {
                set_fault(stream, LSRF_STACK_HEAP_COLLISION);
                return FALSE;
        }
        S32 tm = get_register(stream, LREG_TM);
        if (sp >= tm)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        set_register(stream, LREG_SP, sp);
        return TRUE;
}

inline void lscript_push(U8 *stream, U8 value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= 1;

        if (set_sp(stream, sp))
        {
                *(stream + sp) = value;
        }
}

inline void lscript_push(U8 *stream, S32 value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= LSCRIPTDataSize[LST_INTEGER];

        if (set_sp(stream, sp))
        {
                integer2bytestream(stream, sp, value);
        }
}

inline void lscript_push(U8 *stream, F32 value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= LSCRIPTDataSize[LST_FLOATINGPOINT];

        if (set_sp(stream, sp))
        {
                float2bytestream(stream, sp, value);
        }
}

inline void lscript_push(U8 *stream, LLVector3 &value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= LSCRIPTDataSize[LST_VECTOR];

        if (set_sp(stream, sp))
        {
                vector2bytestream(stream, sp, value);
        }
}

inline void lscript_push(U8 *stream, LLQuaternion &value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= LSCRIPTDataSize[LST_QUATERNION];

        if (set_sp(stream, sp))
        {
                quaternion2bytestream(stream, sp, value);
        }
}

inline void lscript_pusharg(U8 *stream, S32 arg)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= arg;

        set_sp(stream, sp);
}

inline void lscript_poparg(U8 *stream, S32 arg)
{
        S32 sp = get_register(stream, LREG_SP);
        sp += arg;

        set_sp(stream, sp);
}

inline U8 lscript_pop_char(U8 *stream)
{
        S32 sp = get_register(stream, LREG_SP);
        U8 value = *(stream + sp++);
        set_sp(stream, sp);
        return value;
}

inline S32 lscript_pop_int(U8 *stream)
{
        S32 sp = get_register(stream, LREG_SP);
        S32 value = bytestream2integer(stream, sp);
        set_sp(stream, sp);
        return value;
}

inline F32 lscript_pop_float(U8 *stream)
{
        S32 sp = get_register(stream, LREG_SP);
        F32 value = bytestream2float(stream, sp);
        if (!llfinite(value))
        {
                value = 0;
                set_fault(stream, LSRF_MATH);
        }
        set_sp(stream, sp);
        return value;
}

inline void lscript_pop_vector(U8 *stream, LLVector3 &value)
{
        S32 sp = get_register(stream, LREG_SP);
        bytestream2vector(value, stream, sp);
        set_sp(stream, sp);
}

inline void lscript_pop_quaternion(U8 *stream, LLQuaternion &value)
{
        S32 sp = get_register(stream, LREG_SP);
        bytestream2quaternion(value, stream, sp);
        set_sp(stream, sp);
}

inline void lscript_pusharge(U8 *stream, S32 value)
{
        S32 sp = get_register(stream, LREG_SP);
        sp -= value;
        if (set_sp(stream, sp))
        {
                S32 i;
                for (i = 0; i < value; i++)
                {
                        *(stream + sp++) = 0;
                }
        }
}

inline BOOL lscript_check_local(U8 *stream, S32 &address, S32 size)
{
        S32 sp = get_register(stream, LREG_SP);
        S32 bp = get_register(stream, LREG_BP);

        address += size;
        address = bp - address;

        if (address < sp - size)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        S32 tm = get_register(stream, LREG_TM);
        if (address + size > tm)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        return TRUE;
}

inline BOOL lscript_check_global(U8 *stream, S32 &address, S32 size)
{
        S32 gvr = get_register(stream, LREG_GVR);

        // Possibility of overwriting registers?  -- DK 09/07/04
        if (address < 0)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }

        address += gvr;
        S32 gfr = get_register(stream, LREG_GFR);

        if (address + size > gfr)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        return TRUE;
}

inline void lscript_local_store(U8 *stream, S32 address, S32 value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_INTEGER]))
                integer2bytestream(stream, address, value);
}

inline void lscript_local_store(U8 *stream, S32 address, F32 value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_FLOATINGPOINT]))
                float2bytestream(stream, address, value);
}

inline void lscript_local_store(U8 *stream, S32 address, LLVector3 value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_VECTOR]))
                vector2bytestream(stream, address, value);
}

inline void lscript_local_store(U8 *stream, S32 address, LLQuaternion value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_QUATERNION]))
                quaternion2bytestream(stream, address, value);
}

inline void lscript_global_store(U8 *stream, S32 address, S32 value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_INTEGER]))
                integer2bytestream(stream, address, value);
}

inline void lscript_global_store(U8 *stream, S32 address, F32 value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_FLOATINGPOINT]))
                float2bytestream(stream, address, value);
}

inline void lscript_global_store(U8 *stream, S32 address, LLVector3 value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_VECTOR]))
                vector2bytestream(stream, address, value);
}

inline void lscript_global_store(U8 *stream, S32 address, LLQuaternion value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_QUATERNION]))
                quaternion2bytestream(stream, address, value);
}

inline S32 lscript_local_get(U8 *stream, S32 address)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_INTEGER]))
                return bytestream2integer(stream, address);
        return 0;
}

inline void lscript_local_get(U8 *stream, S32 address, F32 &value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_FLOATINGPOINT]))
                value = bytestream2float(stream, address);
        if (!llfinite(value))
        {
                value = 0;
                set_fault(stream, LSRF_MATH);
        }
}

inline void lscript_local_get(U8 *stream, S32 address, LLVector3 &value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_VECTOR]))
                bytestream2vector(value, stream, address);
}

inline void lscript_local_get(U8 *stream, S32 address, LLQuaternion &value)
{
        if (lscript_check_local(stream, address, LSCRIPTDataSize[LST_QUATERNION]))
                bytestream2quaternion(value, stream, address);
}

inline S32 lscript_global_get(U8 *stream, S32 address)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_INTEGER]))
                return bytestream2integer(stream, address);
        return 0;
}

inline void lscript_global_get(U8 *stream, S32 address, F32 &value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_FLOATINGPOINT]))
                value = bytestream2float(stream, address);
        if (!llfinite(value))
        {
                value = 0;
                set_fault(stream, LSRF_MATH);
        }
}

inline void lscript_global_get(U8 *stream, S32 address, LLVector3 &value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_VECTOR]))
                bytestream2vector(value, stream, address);
}

inline void lscript_global_get(U8 *stream, S32 address, LLQuaternion &value)
{
        if (lscript_check_global(stream, address, LSCRIPTDataSize[LST_QUATERNION]))
                bytestream2quaternion(value, stream, address);
}



inline S32 get_state_event_opcoode_start(U8 *stream, S32 state, LSCRIPTStateEventType event)
{
        // get the start of the state table
        S32 sr = get_register(stream, LREG_SR);

        // get the position of the jump to the desired state
        S32 value = get_register(stream, LREG_VN);

        S32 state_offset_offset = 0;
        S32 major_version = 0;
        if (value == LSL2_VERSION1_END_NUMBER)
        {
                major_version = LSL2_MAJOR_VERSION_ONE;
                state_offset_offset = sr + LSCRIPTDataSize[LST_INTEGER] + LSCRIPTDataSize[LST_INTEGER]*2*state;
        }
        else if (value == LSL2_VERSION_NUMBER)
        {
                major_version = LSL2_MAJOR_VERSION_TWO;
                state_offset_offset = sr + LSCRIPTDataSize[LST_INTEGER] + LSCRIPTDataSize[LST_INTEGER]*3*state;
        }
        if ( state_offset_offset < 0 || state_offset_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        // get the actual position in memory of the desired state
        S32 state_offset = sr + bytestream2integer(stream, state_offset_offset);
        if ( state_offset < 0 || state_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        // save that value
        S32 state_offset_base = state_offset;

        // jump past the state name
        S32 event_jump_offset = state_offset_base + bytestream2integer(stream, state_offset);

        // get the location of the event offset
        S32 event_offset = event_jump_offset + LSCRIPTDataSize[LST_INTEGER]*2*get_event_handler_jump_position(get_event_register(stream, LREG_ER, major_version), event);
        if ( event_offset < 0 || event_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        // now, jump to the event
        S32 event_start = bytestream2integer(stream, event_offset);
        if ( event_start < 0 || event_start > TOP_OF_MEMORY )
        {
                return -1;
        }
        event_start += event_jump_offset;

        S32 event_start_original = event_start;

        // now skip past the parameters
        S32 opcode_offset = bytestream2integer(stream, event_start);
        if ( opcode_offset < 0 || opcode_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        return opcode_offset + event_start_original;
}


inline U64 get_handled_events(U8 *stream, S32 state)
{
        U64 retvalue = 0;
        // get the start of the state table
        S32 sr = get_register(stream, LREG_SR);

        // get the position of the jump to the desired state
        S32 value = get_register(stream, LREG_VN);
        S32 state_handled_offset = 0;
        if (value == LSL2_VERSION1_END_NUMBER)
        {
                state_handled_offset = sr + LSCRIPTDataSize[LST_INTEGER]*2*state + 2*LSCRIPTDataSize[LST_INTEGER];      
                retvalue = bytestream2integer(stream, state_handled_offset);
        }
        else if (value == LSL2_VERSION_NUMBER)
        {
                state_handled_offset = sr + LSCRIPTDataSize[LST_INTEGER]*3*state + 2*LSCRIPTDataSize[LST_INTEGER];      
                retvalue = bytestream2u64(stream, state_handled_offset);
        }

        // get the handled events
        return retvalue;
}

// Returns -1 on error
inline S32 get_event_stack_size(U8 *stream, S32 state, LSCRIPTStateEventType event)
{
        // get the start of the state table
        S32 sr = get_register(stream, LREG_SR);

        // get state offset
        S32 value = get_register(stream, LREG_VN);
        S32 state_offset_offset = 0;
        S32 major_version = 0;
        if (value == LSL2_VERSION1_END_NUMBER)
        {
                major_version = LSL2_MAJOR_VERSION_ONE;
                state_offset_offset = sr + LSCRIPTDataSize[LST_INTEGER] + LSCRIPTDataSize[LST_INTEGER]*2*state;
        }
        else if (value == LSL2_VERSION_NUMBER)
        {
                major_version = LSL2_MAJOR_VERSION_TWO;
                state_offset_offset = sr + LSCRIPTDataSize[LST_INTEGER] + LSCRIPTDataSize[LST_INTEGER]*3*state;
        }

        if ( state_offset_offset < 0 || state_offset_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        S32 state_offset = bytestream2integer(stream, state_offset_offset);
        state_offset += sr;

        state_offset_offset = state_offset;
        if ( state_offset_offset < 0 || state_offset_offset > TOP_OF_MEMORY )
        {
                return -1;
        }

        // skip to jump table
        S32 jump_table = bytestream2integer(stream, state_offset_offset);

        jump_table += state_offset;
        if ( jump_table < 0 || jump_table > TOP_OF_MEMORY )
        {
                return -1;
        }

        // get the position of the jump to the desired state
        S32 stack_size_offset = jump_table + LSCRIPTDataSize[LST_INTEGER]*2*get_event_handler_jump_position(get_event_register(stream, LREG_ER, major_version), event) + LSCRIPTDataSize[LST_INTEGER];

        // get the handled events
        S32 stack_size = bytestream2integer(stream, stack_size_offset);
        if ( stack_size < 0 || stack_size > TOP_OF_MEMORY )
        {
                return -1;
        }

        return stack_size;
}

inline LSCRIPTStateEventType return_first_event(S32 event)
{
        S32 count = 1;
        while (count < LSTT_EOF)
        {
                if (event & 0x1)
                {
                        return (LSCRIPTStateEventType) count;
                }
                else
                {
                        event >>= 1;
                        count++;
                }
        }
        return LSTT_NULL;
}


// the safe instruction versions of these commands will only work if offset is between
// GFR and HR, meaning that it is an instruction (more or less) in global functions or event handlers

inline BOOL safe_instruction_check_address(U8 *stream, S32 offset, S32 size)
{
        S32 gfr = get_register(stream, LREG_GFR);
        if (offset < gfr)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        else
        {
                S32 hr = get_register(stream, LREG_HR);
                if (offset + size > hr)
                {
                        set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                        return FALSE;
                }
                else
                {
                        return TRUE;
                }
        }
}

inline BOOL safe_heap_check_address(U8 *stream, S32 offset, S32 size)
{
        S32 hr = get_register(stream, LREG_HR);
        if (offset < hr)
        {
                set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                return FALSE;
        }
        else
        {
                S32 hp = get_register(stream, LREG_HP);
                if (offset + size > hp)
                {
                        set_fault(stream, LSRF_BOUND_CHECK_ERROR);
                        return FALSE;
                }
                else
                {
                        return TRUE;
                }
        }
}

inline U8 safe_instruction_bytestream2byte(U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, 1))
        {
                return *(stream + offset++);
        }
        else
        {
                return 0;
        }
}

inline void safe_instruction_byte2bytestream(U8 *stream, S32 &offset, U8 byte)
{
        if (safe_instruction_check_address(stream, offset, 1))
        {
                *(stream + offset++) = byte;
        }
}

inline S32 safe_instruction_bytestream2integer(U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_INTEGER]))
        {
                return (bytestream2integer(stream, offset));
        }
        else
        {
                return 0;
        }
}

inline void safe_instruction_integer2bytestream(U8 *stream, S32 &offset, S32 value)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_INTEGER]))
        {
                integer2bytestream(stream, offset, value);
        }
}

inline U16 safe_instruction_bytestream2u16(U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, 2))
        {
                return (bytestream2u16(stream, offset));
        }
        else
        {
                return 0;
        }
}

inline void safe_instruction_u162bytestream(U8 *stream, S32 &offset, U16 value)
{
        if (safe_instruction_check_address(stream, offset, 2))
        {
                u162bytestream(stream, offset, value);
        }
}

inline F32 safe_instruction_bytestream2float(U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_INTEGER]))
        {
                F32 value = bytestream2float(stream, offset);
                if (!llfinite(value))
                {
                        value = 0;
                        set_fault(stream, LSRF_MATH);
                }
                return value;
        }
        else
        {
                return 0;
        }
}

inline void safe_instruction_float2bytestream(U8 *stream, S32 &offset, F32 value)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_FLOATINGPOINT]))
        {
                float2bytestream(stream, offset, value);
        }
}

inline void safe_instruction_bytestream2char(char *buffer, U8 *stream, S32 &offset, S32 buffsize)
{
        // This varies from the old method. Previously, we would copy up until we got an error,
        // then halt the script via safe_isntruction_check_address. Now we don't bother
        // copying a thing if there's an error.

        if( safe_instruction_check_address(stream, offset, strlen( (const char *)stream + offset ) + 1 ) )
        {
                // Takes the same parms as this function. Won't overread, per above check.
                bytestream2char( buffer, stream, offset, buffsize );
        }
        else
        {
                // Truncate - no point in copying
                *buffer = 0;
        }
}

inline void safe_instruction_bytestream_count_char(U8 *stream, S32 &offset)
{
        while (  (safe_instruction_check_address(stream, offset, 1))
                   &&(*(stream + offset++)))
                ;
}

inline void safe_heap_bytestream_count_char(U8 *stream, S32 &offset)
{
        while (  (safe_heap_check_address(stream, offset, 1))
                   &&(*(stream + offset++)))
                ;
}

inline void safe_instruction_char2bytestream(U8 *stream, S32 &offset, char *buffer)
{
        while (  (safe_instruction_check_address(stream, offset, 1))
                   &&(*(stream + offset++) = *buffer++))
                ;
}

inline void safe_instruction_bytestream2vector(LLVector3 &value, U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_VECTOR]))
        {
                bytestream2vector(value, stream, offset);
        }
}

inline void safe_instruction_vector2bytestream(U8 *stream, S32 &offset, LLVector3 &value)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_VECTOR]))
        {
                vector2bytestream(stream, offset, value);
        }
}

inline void safe_instruction_bytestream2quaternion(LLQuaternion &value, U8 *stream, S32 &offset)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_QUATERNION]))
        {
                bytestream2quaternion(value, stream, offset);
        }
}

inline void safe_instruction_quaternion2bytestream(U8 *stream, S32 &offset, LLQuaternion &value)
{
        if (safe_instruction_check_address(stream, offset, LSCRIPTDataSize[LST_QUATERNION]))
        {
                quaternion2bytestream(stream, offset, value);
        }
}

static inline LSCRIPTType char2type(char type)
{
                switch(type)
                {
                case 'i':
                        return LST_INTEGER;
                case 'f':
                        return LST_FLOATINGPOINT;
                case 's':
                        return LST_STRING;
                case 'k':
                        return LST_KEY;
                case 'v':
                        return LST_VECTOR;
                case 'q':
                        return LST_QUATERNION;
                case 'l':
                        return LST_LIST;
                default:
                        return LST_NULL;
                }
}

#endif

---