/**

  * ================================================================

  * SourcePawn (C)2004-2007 AlliedModders LLC.  All rights reserved.

  * ================================================================

  *

  * This file is not open source and may not be copied without explicit

  * written permission of AlliedModders LLC.  This file may not be redistributed 

  * in whole or significant part.

  * For information, see LICENSE.txt or http://www.sourcemod.net/license.php

  *

  * Version: $Id$

  */

 #include <string.h>

 #include <stdarg.h>

 #include <assert.h>

 #include <limits.h>

 #include "sp_vm_api.h"

 #include "sp_vm_basecontext.h"

 #include "sp_vm_engine.h"

 using namespace SourcePawn;

 extern SourcePawnEngine g_SourcePawn;

 #define CELLBOUNDMAX	(INT_MAX/sizeof(cell_t))

 #define STACKMARGIN		((cell_t)(16*sizeof(cell_t)))

 int GlobalDebugBreak(sp_context_t *ctx, uint32_t frm, uint32_t cip)

 {

 	g_SourcePawn.RunTracer(ctx, frm, cip);

 	return SP_ERROR_NONE;

 }

 BaseContext::BaseContext(sp_context_t *_ctx)

 {

 	ctx = _ctx;

 	ctx->context = this;

 	ctx->dbreak = GlobalDebugBreak;

 	m_InExec = false;

 	m_CustomMsg = false;

 	m_funcsnum = ctx->vmbase->FunctionCount(ctx);

 	m_priv_funcs = NULL;

 	m_pub_funcs = NULL;

 	/**

 	 * Note: Since the m_plugin member will never change,

 	 * it is safe to assume the function count will never change

 	 */

 	if (m_funcsnum && m_priv_funcs == NULL)

 	{

 		m_priv_funcs = new CFunction *[m_funcsnum];

 		memset(m_priv_funcs, 0, sizeof(CFunction *) * m_funcsnum);

 	} else {

 		m_priv_funcs = NULL;

 	}

 	if (ctx->plugin->info.publics_num && m_pub_funcs == NULL)

 	{

 		m_pub_funcs = new CFunction *[ctx->plugin->info.publics_num];

 		memset(m_pub_funcs, 0, sizeof(CFunction *) * ctx->plugin->info.publics_num);

 	} else {

 		m_pub_funcs = NULL;

 	}

 }

 void BaseContext::FlushFunctionCache(bool remove)

 {

 	if (m_pub_funcs)

 	{

 		for (uint32_t i=0; i<ctx->plugin->info.publics_num; i++)

 		{

 			if (remove)

 			{

 				delete m_pub_funcs[i];

 				m_pub_funcs[i] = NULL;

 			} else if (m_pub_funcs[i]) {

 				m_pub_funcs[i]->Invalidate();

 			}

 		}

 	}

 	if (m_priv_funcs)

 	{

 		for (unsigned int i=0; i<m_funcsnum; i++)

 		{

 			if (remove)

 			{

 				delete m_priv_funcs[i];

 				m_priv_funcs[i] = NULL;

 			} else if (m_priv_funcs[i]) {

 				m_priv_funcs[i]->Invalidate();

 			}

 		}

 	}

 }

 BaseContext::~BaseContext()

 {

 	FlushFunctionCache(true);

 	delete [] m_pub_funcs;

 	m_pub_funcs = NULL;

 	delete [] m_priv_funcs;

 	m_priv_funcs = NULL;

 }

 void BaseContext::SetContext(sp_context_t *_ctx)

 {

 	if (!_ctx)

 	{

 		return;

 	}

 	ctx = _ctx;

 	ctx->context = this;

 	ctx->dbreak = GlobalDebugBreak;

 	FlushFunctionCache(false);

 }

 IVirtualMachine *BaseContext::GetVirtualMachine()

 {

 	return (IVirtualMachine *)ctx->vmbase;

 }

 sp_context_t *BaseContext::GetContext()

 {

 	return ctx;

 }

 bool BaseContext::IsDebugging()

 {

 	return (ctx->flags & SPFLAG_PLUGIN_DEBUG);

 }

 int BaseContext::SetDebugBreak(SPVM_DEBUGBREAK newpfn, SPVM_DEBUGBREAK *oldpfn)

 {

 	if (!IsDebugging())

 	{

 		return SP_ERROR_NOTDEBUGGING;

 	}

 	*oldpfn = ctx->dbreak;

 	ctx->dbreak = newpfn;

 	return SP_ERROR_NONE;

 }

 IPluginDebugInfo *BaseContext::GetDebugInfo()

 {

 	return this;

 }

 int BaseContext::Execute(uint32_t code_addr, cell_t *result)

 {

 	if ((ctx->flags & SPFLAG_PLUGIN_PAUSED) == SPFLAG_PLUGIN_PAUSED)

 	{

 		return SP_ERROR_NOT_RUNNABLE;

 	}

 	IVirtualMachine *vm = (IVirtualMachine *)ctx->vmbase;

 	uint32_t pushcount = ctx->pushcount;

 	int err;

 	PushCell(pushcount++);

 	ctx->pushcount = 0;

 	cell_t save_sp = ctx->sp;

 	cell_t save_hp = ctx->hp;

 	bool wasExec = m_InExec;

 	/* Clear the error state, if any */

 	ctx->n_err = SP_ERROR_NONE;

 	ctx->n_idx = 0;

 	m_InExec = true;

 	m_MsgCache[0] = '\0';

 	m_CustomMsg = false;

 	g_SourcePawn.PushTracer(ctx);

 	err = vm->ContextExecute(ctx, code_addr, result);

 	m_InExec = wasExec;

 	/**

 	 * :TODO: Calling from a plugin in here will erase the cached message...

 	 * Should that be documented?

 	 */

 	g_SourcePawn.PopTracer(err, m_CustomMsg ? m_MsgCache : NULL);

 #if defined _DEBUG

 	if (err == SP_ERROR_NONE)

 	{

 		assert(ctx->sp - pushcount * sizeof(cell_t) == save_sp);

 		assert(ctx->hp == save_hp);

 	}

 #endif

 	if (err != SP_ERROR_NONE)

 	{

 		ctx->sp = save_sp;

 		ctx->hp = save_hp;

 	}

 	return err;

 }

 void BaseContext::SetErrorMessage(const char *msg, va_list ap)

 {

 	m_CustomMsg = true;

 	vsnprintf(m_MsgCache, sizeof(m_MsgCache), msg, ap);

 }

 cell_t BaseContext::ThrowNativeErrorEx(int error, const char *msg, ...)

 {

 	if (!m_InExec)

 	{

 		return 0;

 	}

 	ctx->n_err = error;

 	if (msg)

 	{

 		va_list ap;

 		va_start(ap, msg);

 		SetErrorMessage(msg, ap);

 		va_end(ap);

 	}

 	return 0;

 }

 cell_t BaseContext::ThrowNativeError(const char *msg, ...)

 {

 	if (!m_InExec)

 	{

 		return 0;

 	}

 	ctx->n_err = SP_ERROR_NATIVE;

 	if (msg)

 	{

 		va_list ap;

 		va_start(ap, msg);

 		SetErrorMessage(msg, ap);

 		va_end(ap);

 	}

 	return 0;

 }

 int BaseContext::HeapAlloc(unsigned int cells, cell_t *local_addr, cell_t **phys_addr)

 {

 	cell_t *addr;

 	ucell_t realmem;

 #if 0

 	if (cells > CELLBOUNDMAX)

 	{

 		return SP_ERROR_ARAM;

 	}

 #else

 	assert(cells < CELLBOUNDMAX);

 #endif

 	realmem = cells * sizeof(cell_t);

 	/**

 	 * Check if the space between the heap and stack is sufficient.

 	 */

 	if ((cell_t)(ctx->sp - ctx->hp - realmem) < STACKMARGIN)

 	{

 		return SP_ERROR_HEAPLOW;

 	}

 	addr = (cell_t *)(ctx->memory + ctx->hp);

 	/* store size of allocation in cells */

 	*addr = (cell_t)cells;

 	addr++;

 	ctx->hp += sizeof(cell_t);

 	*local_addr = ctx->hp;

 	if (phys_addr)

 	{

 		*phys_addr = addr;

 	}

 	ctx->hp += realmem;

 	return SP_ERROR_NONE;

 }

 int BaseContext::HeapPop(cell_t local_addr)

 {

 	cell_t cellcount;

 	cell_t *addr;

 	/* check the bounds of this address */

 	local_addr -= sizeof(cell_t);

 	if (local_addr < ctx->heap_base || local_addr >= ctx->sp)

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	addr = (cell_t *)(ctx->memory + local_addr);

 	cellcount = (*addr) * sizeof(cell_t);

 	/* check if this memory count looks valid */

 	if ((signed)(ctx->hp - cellcount - sizeof(cell_t)) != local_addr)

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	ctx->hp = local_addr;

 	return SP_ERROR_NONE;

 }

 int BaseContext::HeapRelease(cell_t local_addr)

 {

 	if (local_addr < ctx->heap_base)

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	ctx->hp = local_addr - sizeof(cell_t);

 	return SP_ERROR_NONE;

 }

 int BaseContext::FindNativeByName(const char *name, uint32_t *index)

 {

 	int high;

 	high = ctx->plugin->info.natives_num - 1;

 	for (uint32_t i=0; i<ctx->plugin->info.natives_num; i++)

 	{

 		if (strcmp(ctx->natives[i].name, name) == 0)

 		{

 			if (index)

 			{

 				*index = i;

 			}

 			return SP_ERROR_NONE;

 		}

 	}

 	return SP_ERROR_NOT_FOUND;

 }

 int BaseContext::GetNativeByIndex(uint32_t index, sp_native_t **native)

 {

 	if (index >= ctx->plugin->info.natives_num)

 	{

 		return SP_ERROR_INDEX;

 	}

 	if (native)

 	{

 		*native = &(ctx->natives[index]);

 	}

 	return SP_ERROR_NONE;

 }

 uint32_t BaseContext::GetNativesNum()

 {

 	return ctx->plugin->info.natives_num;

 }

 int BaseContext::FindPublicByName(const char *name, uint32_t *index)

 {

 	int diff, high, low;

 	uint32_t mid;

 	high = ctx->plugin->info.publics_num - 1;

 	low = 0;

 	while (low <= high)

 	{

 		mid = (low + high) / 2;

 		diff = strcmp(ctx->publics[mid].name, name);

 		if (diff == 0)

 		{

 			if (index)

 			{

 				*index = mid;

 			}

 			return SP_ERROR_NONE;

 		} else if (diff < 0) {

 			low = mid + 1;

 		} else {

 			high = mid - 1;

 		}

 	}

 	return SP_ERROR_NOT_FOUND;

 }

 int BaseContext::GetPublicByIndex(uint32_t index, sp_public_t **pblic)

 {

 	if (index >= ctx->plugin->info.publics_num)

 	{

 		return SP_ERROR_INDEX;

 	}

 	if (pblic)

 	{

 		*pblic = &(ctx->publics[index]);

 	}

 	return SP_ERROR_NONE;

 }

 uint32_t BaseContext::GetPublicsNum()

 {

 	return ctx->plugin->info.publics_num;

 }

 int BaseContext::GetPubvarByIndex(uint32_t index, sp_pubvar_t **pubvar)

 {

 	if (index >= ctx->plugin->info.pubvars_num)

 	{

 		return SP_ERROR_INDEX;

 	}

 	if (pubvar)

 	{

 		*pubvar = &(ctx->pubvars[index]);

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::FindPubvarByName(const char *name, uint32_t *index)

 {

 	int diff, high, low;

 	uint32_t mid;

 	high = ctx->plugin->info.pubvars_num - 1;

 	low = 0;

 	while (low <= high)

 	{

 		mid = (low + high) / 2;

 		diff = strcmp(ctx->pubvars[mid].name, name);

 		if (diff == 0)

 		{

 			if (index)

 			{

 				*index = mid;

 			}

 			return SP_ERROR_NONE;

 		} else if (diff < 0) {

 			low = mid + 1;

 		} else {

 			high = mid - 1;

 		}

 	}

 	return SP_ERROR_NOT_FOUND;

 }

 int BaseContext::GetPubvarAddrs(uint32_t index, cell_t *local_addr, cell_t **phys_addr)

 {

 	if (index >= ctx->plugin->info.pubvars_num)

 	{

 		return SP_ERROR_INDEX;

 	}

 	*local_addr = ctx->plugin->info.pubvars[index].address;

 	*phys_addr = ctx->pubvars[index].offs;

 	return SP_ERROR_NONE;

 }

 uint32_t BaseContext::GetPubVarsNum()

 {

 	return ctx->plugin->info.pubvars_num;

 }

 int BaseContext::BindNatives(const sp_nativeinfo_t *natives, unsigned int num, int overwrite)

 {

 	uint32_t i, j, max;

 	max = ctx->plugin->info.natives_num;

 	for (i=0; i<max; i++)

 	{

 		if ((ctx->natives[i].status == SP_NATIVE_BOUND) && !overwrite)

 		{

 			continue;

 		}

 		for (j=0; (natives[j].name) && (!num || j<num); j++)

 		{

 			if (!strcmp(ctx->natives[i].name, natives[j].name))

 			{

 				ctx->natives[i].pfn = natives[j].func;

 				ctx->natives[i].status = SP_NATIVE_BOUND;

 			}

 		}

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::BindNative(const sp_nativeinfo_t *native)

 {

 	uint32_t index;

 	int err;

 	if ((err = FindNativeByName(native->name, &index)) != SP_ERROR_NONE)

 	{

 		return err;

 	}

 	ctx->natives[index].pfn = native->func;

 	ctx->natives[index].status = SP_NATIVE_BOUND;

 	return SP_ERROR_NONE;

 }

 int BaseContext::BindNativeToAny(SPVM_NATIVE_FUNC native)

 {

 	uint32_t nativesnum, i;

 	nativesnum = ctx->plugin->info.natives_num;

 	for (i=0; i<nativesnum; i++)

 	{

 		if (ctx->natives[i].status == SP_NATIVE_UNBOUND)

 		{

 			ctx->natives[i].pfn = native;

 			ctx->natives[i].status = SP_NATIVE_BOUND;

 		}

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::LocalToPhysAddr(cell_t local_addr, cell_t **phys_addr)

 {

 	if (((local_addr >= ctx->hp) && (local_addr < ctx->sp)) || (local_addr < 0) || ((ucell_t)local_addr >= ctx->mem_size))

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	if (phys_addr)

 	{

 		*phys_addr = (cell_t *)(ctx->memory + local_addr);

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::PushCell(cell_t value)

 {

 	if ((ctx->hp + STACKMARGIN) > (cell_t)(ctx->sp - sizeof(cell_t)))

 	{

 		return SP_ERROR_STACKLOW;

 	}

 	ctx->sp -= sizeof(cell_t);

 	*(cell_t *)(ctx->memory + ctx->sp) = value;

 	ctx->pushcount++;

 	return SP_ERROR_NONE;

 }

 int BaseContext::PushCellsFromArray(cell_t array[], unsigned int numcells)

 {

 	unsigned int i;

 	int err;

 	for (i=0; i<numcells; i++)

 	{

 		if ((err = PushCell(array[i])) != SP_ERROR_NONE)

 		{

 			ctx->sp += (cell_t)(i * sizeof(cell_t));

 			ctx->pushcount -= i;

 			return err;

 		}

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::PushCellArray(cell_t *local_addr, cell_t **phys_addr, cell_t array[], unsigned int numcells)

 {

 	cell_t *ph_addr;

 	int err;

 	if ((err = HeapAlloc(numcells, local_addr, &ph_addr)) != SP_ERROR_NONE)

 	{

 		return err;

 	}

 	memcpy(ph_addr, array, numcells * sizeof(cell_t));

 	if ((err = PushCell(*local_addr)) != SP_ERROR_NONE)

 	{

 		HeapRelease(*local_addr);

 		return err;

 	}

 	if (phys_addr)

 	{

 		*phys_addr = ph_addr;

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::LocalToString(cell_t local_addr, char **addr)

 {

 	if (((local_addr >= ctx->hp) && (local_addr < ctx->sp)) || (local_addr < 0) || ((ucell_t)local_addr >= ctx->mem_size))

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	*addr = (char *)(ctx->memory + local_addr);

 	return SP_ERROR_NONE;

 }

 int BaseContext::PushString(cell_t *local_addr, char **phys_addr, const char *string)

 {

 	char *ph_addr;

 	int err;

 	unsigned int len, numcells = ((len=strlen(string)) + sizeof(cell_t)) / sizeof(cell_t);

 	if ((err = HeapAlloc(numcells, local_addr, (cell_t **)&ph_addr)) != SP_ERROR_NONE)

 	{

 		return err;

 	}

 	memcpy(ph_addr, string, len);

 	ph_addr[len] = '\0';

 	if ((err = PushCell(*local_addr)) != SP_ERROR_NONE)

 	{

 		HeapRelease(*local_addr);

 		return err;

 	}

 	if (phys_addr)

 	{

 		*phys_addr = ph_addr;

 	}

 	return SP_ERROR_NONE;

 }

 int BaseContext::StringToLocal(cell_t local_addr, size_t chars, const char *source)

 {

 	char *dest;

 	int len;

 	if (((local_addr >= ctx->hp) && (local_addr < ctx->sp)) || (local_addr < 0) || ((ucell_t)local_addr >= ctx->mem_size))

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	len = strlen(source);

 	dest = (char *)(ctx->memory + local_addr);

 	if ((size_t)len >= chars)

 	{

 		len = chars - 1;

 	}

 	if (len <= 0)

 	{

 		return SP_ERROR_NONE;

 	}

 	memcpy(dest, source, len);

 	dest[len] = '\0';

 	return SP_ERROR_NONE;

 }

 inline int __CheckValidChar(char *c)

 {

 	int count;

 	int bytecount = 0;

 	for (count=1; (*c & 0xC0) == 0x80; count++)

 	{

 		c--;

 	}

 	switch (*c & 0xF0)

 	{

 	case 0xC0:

 	case 0xD0:

 		{

 			bytecount = 2;

 			break;

 		}

 	case 0xE0:

 		{

 			bytecount = 3;

 			break;

 		}

 	case 0xF0:

 		{

 			bytecount = 4;

 			break;

 		}

 	}

 	if (bytecount != count)

 	{

 		return count;

 	}

 	return 0;

 }

 int BaseContext::StringToLocalUTF8(cell_t local_addr, size_t maxbytes, const char *source, size_t *wrtnbytes)

 {

 	char *dest;

 	int len;

 	bool needtocheck = false;

 	if (((local_addr >= ctx->hp) && (local_addr < ctx->sp)) || (local_addr < 0) || ((ucell_t)local_addr >= ctx->mem_size))

 	{

 		return SP_ERROR_INVALID_ADDRESS;

 	}

 	len = strlen(source);

 	dest = (char *)(ctx->memory + local_addr);

 	if ((size_t)len >= maxbytes)

 	{

 		len = maxbytes - 1;

 		needtocheck = true;

 	}

 	if (len <= 0)

 	{

 		return SP_ERROR_NONE;

 	}

 	memcpy(dest, source, len);

 	if ((dest[len-1] & 1<<7) && needtocheck)

 	{

 		len -= __CheckValidChar(dest+len-1);

 	}

 	dest[len] = '\0';

 	if (wrtnbytes)

 	{

 		*wrtnbytes = len;

 	}

 	return SP_ERROR_NONE;

 }

 #define USHR(x) ((unsigned int)(x)>>1)

 int BaseContext::LookupFile(ucell_t addr, const char **filename)

 {

 	int high, low, mid;

 	high = ctx->plugin->debug.files_num;

 	low = -1;

 	while (high - low > 1)

 	{

 		mid = USHR(low + high);

 		if (ctx->files[mid].addr <= addr)

 		{

 			low = mid;

 		} else {

 			high = mid;

 		}

 	}

 	if (low == -1)

 	{

 		return SP_ERROR_NOT_FOUND;

 	}

 	*filename = ctx->files[low].name;

 	return SP_ERROR_NONE;

 }

 int BaseContext::LookupFunction(ucell_t addr, const char **name)

 {

 	uint32_t iter, max = ctx->plugin->debug.syms_num;

 	for (iter=0; iter<max; iter++)

 	{

 		if ((ctx->symbols[iter].sym->ident == SP_SYM_FUNCTION) 

 			&& (ctx->symbols[iter].codestart <= addr) 

 			&& (ctx->symbols[iter].codeend > addr))

 		{

 			break;

 		}

 	}

 	if (iter >= max)

 	{

 		return SP_ERROR_NOT_FOUND;

 	}

 	*name = ctx->symbols[iter].name;

 	return SP_ERROR_NONE;

 }

 int BaseContext::LookupLine(ucell_t addr, uint32_t *line)

 {

 	int high, low, mid;

 	high = ctx->plugin->debug.lines_num;

 	low = -1;

 	while (high - low > 1)

 	{

 		mid = USHR(low + high);

 		if (ctx->lines[mid].addr <= addr)

 		{

 			low = mid;

 		} else {

 			high = mid;

 		}

 	}

 	if (low == -1)

 	{

 		return SP_ERROR_NOT_FOUND;

 	}

 	/* Since the CIP occurs BEFORE the line, we have to add one */

 	*line = ctx->lines[low].line + 1;

 	return SP_ERROR_NONE;

 }

 IPluginFunction *BaseContext::GetFunctionById(funcid_t func_id)

 {

 	CFunction *pFunc = NULL;

 	if (func_id & 1)

 	{

 		func_id >>= 1;

 		if (func_id >= ctx->plugin->info.publics_num)

 		{

 			return NULL;

 		}

 		pFunc = m_pub_funcs[func_id];

 		if (!pFunc)

 		{

 			m_pub_funcs[func_id] = new CFunction(ctx->publics[func_id].code_offs, this);

 			pFunc = m_pub_funcs[func_id];

 		} else if (pFunc->IsInvalidated()) {

 			pFunc->Set(ctx->publics[func_id].code_offs, this);

 		}

 	} else {

 		/* :TODO: currently not used */

 #if 0

 		func_id >>= 1;

 		unsigned int index;

 		if (!g_pVM->FunctionLookup(ctx, func_id, &index))

 		{

 			return NULL;

 		}

 		pFunc = m_priv_funcs[func_id];

 		if (!pFunc)

 		{

 			m_priv_funcs[func_id] = new CFunction(save, this);

 			pFunc = m_priv_funcs[func_id];

 		}

 #endif

 		assert(false);

 	}

 	return pFunc;

 }

 IPluginFunction *BaseContext::GetFunctionByName(const char *public_name)

 {

 	uint32_t index;

 	if (FindPublicByName(public_name, &index) != SP_ERROR_NONE)

 	{

 		return NULL;

 	}

 	CFunction *pFunc = m_pub_funcs[index];

 	if (!pFunc)

 	{

 		sp_public_t *pub = NULL;

 		GetPublicByIndex(index, &pub);

 		if (pub)

 		{

 			m_pub_funcs[index] = new CFunction(pub->code_offs, this);

 		}

 		pFunc = m_pub_funcs[index];

 	} else if (pFunc->IsInvalidated()) {

 		sp_public_t *pub = NULL;

 		GetPublicByIndex(index, &pub);

 		if (pub)

 		{

 			pFunc->Set(pub->code_offs, this);

 		} else {

 			pFunc = NULL;

 		}

 	}

 	return pFunc;

 }

 #if defined SOURCEMOD_BUILD

 SourceMod::IdentityToken_t *BaseContext::GetIdentity()

 {

 	return m_pToken;

 }

 void BaseContext::SetIdentity(SourceMod::IdentityToken_t *token)