cs.c - platform/external/capstone - Git at Google

 /* Capstone Disassembler Engine */
 /* By Nguyen Anh Quynh <[email protected]>, 2013> */

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <capstone.h>

 #include "cs_priv.h"

 #include "MCRegisterInfo.h"

 #include "utils.h"

 void (*arch_init[MAX_ARCH])(cs_struct *) = { NULL };
 cs_err (*arch_option[MAX_ARCH]) (cs_struct*, cs_opt_type, size_t value);

 unsigned int all_arch = 0;

 unsigned int cs_version(int *major, int *minor)
 {
 	*major = CS_API_MAJOR;
 	*minor = CS_API_MINOR;

 	return (CS_API_MAJOR << 8) + CS_API_MINOR;
 }

 bool cs_support(cs_arch arch)
 {
 	if (arch == CS_ARCH_ALL)
 		return all_arch == ((1 << CS_ARCH_ARM) | (1 << CS_ARCH_ARM64) |
 				(1 << CS_ARCH_MIPS) | (1 << CS_ARCH_X86));

 	return all_arch & (1 << arch);
 }

 cs_err cs_errno(csh handle)
 {
 	if (!handle)
 		return CS_ERR_CSH;

 	cs_struct *ud = (cs_struct *)(uintptr_t)handle;

 	return ud->errnum;
 }

 cs_err cs_open(cs_arch arch, cs_mode mode, csh *handle)
 {
 	cs_struct *ud;

 	ud = calloc(1, sizeof(*ud));
 	if (!ud) {
 		// memory insufficient
 		return CS_ERR_MEM;
 	}

 	if (arch < CS_ARCH_MAX && arch_init[ud->arch]) {
 		ud->errnum = CS_ERR_OK;
 		ud->arch = arch;
 		ud->mode = mode;
 		ud->big_endian = mode & CS_MODE_BIG_ENDIAN;
 		ud->reg_name = NULL;
 		ud->detail = CS_OPT_ON;	// by default break instruction into details

 		arch_init[ud->arch](ud);
 	} else {
 		*handle = 0;
 		return CS_ERR_ARCH;
 	}

 	*handle = (uintptr_t)ud;

 	return CS_ERR_OK;
 }

 cs_err cs_close(csh handle)
 {
 	if (!handle)
 		return CS_ERR_CSH;

 	cs_struct *ud = (cs_struct *)(uintptr_t)handle;

 	switch (ud->arch) {
 		case CS_ARCH_X86:
 			break;
 		case CS_ARCH_ARM:
 		case CS_ARCH_MIPS:
 		case CS_ARCH_ARM64:
 			free(ud->printer_info);
 			break;
 		default:	// unsupported architecture
 			return CS_ERR_HANDLE;
 	}

 	memset(ud, 0, sizeof(*ud));
 	free(ud);

 	return CS_ERR_OK;
 }

 #define MIN(x, y) ((x) < (y) ? (x) : (y))

 // fill insn with mnemonic & operands info
 static void fill_insn(cs_struct *handle, cs_insn *insn, char *buffer, MCInst *mci,
 		PostPrinter_t printer, const uint8_t *code)
 {
 	if (handle->detail) {
 		memcpy(insn, &mci->pub_insn, sizeof(*insn));

 		// fill the instruction bytes
 		memcpy(insn->bytes, code, MIN(sizeof(insn->bytes), insn->size));

 	} else {
 		insn->address = mci->address;
 		insn->size = mci->insn_size;
 	}

 	// map internal instruction opcode to public insn ID
 	if (handle->insn_id)
 		handle->insn_id(insn, MCInst_getOpcode(mci), handle->detail);

 	// alias instruction might have ID saved in OpcodePub
 	if (MCInst_getOpcodePub(mci))
 		insn->id = MCInst_getOpcodePub(mci);

 	// post printer handles some corner cases (hacky)
 	if (printer)
 		printer((csh)handle, insn, buffer);

 	// fill in mnemonic & operands
 	// find first space or tab
 	char *sp = buffer;
 	for (sp = buffer; *sp; sp++)
 		if (*sp == ' '||*sp == '\t')
 			break;
 	if (*sp) {
 		*sp = '\0';
 		// find the next non-space char
 		sp++;
 		for (; ((*sp == ' ') || (*sp == '\t')); sp++);
 		strncpy(insn->op_str, sp, sizeof(insn->op_str) - 1);
 		insn->op_str[sizeof(insn->op_str) - 1] = '\0';
 	} else
 		insn->op_str[0] = '\0';

 	strncpy(insn->mnemonic, buffer, sizeof(insn->mnemonic) - 1);
 	insn->mnemonic[sizeof(insn->mnemonic) - 1] = '\0';
 }

 cs_err cs_option(csh ud, cs_opt_type type, size_t value)
 {
 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;
 	if (!handle)
 		return CS_ERR_CSH;

 	if (type == CS_OPT_DETAIL) {
 		handle->detail = value;
 		return CS_ERR_OK;
 	}

 	return arch_option[handle->arch](handle, type, value);
 }

 size_t cs_disasm(csh ud, const uint8_t *buffer, size_t size, uint64_t offset, size_t count, cs_insn *insn)
 {
 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;
 	MCInst mci;
 	uint16_t insn_size;
 	size_t c = 0;

 	if (!handle) {
 		// FIXME: handle this case?
 		// handle->errnum = CS_ERR_HANDLE;
 		return 0;
 	}

 	handle->errnum = CS_ERR_OK;
 	memset(insn, 0, count * sizeof(*insn));

 	while (size > 0) {
 		MCInst_Init(&mci);
 		mci.detail = handle->detail;
 		mci.mode = handle->mode;

 		bool r = handle->disasm(ud, buffer, size, &mci, &insn_size, offset, handle->getinsn_info);
 		if (r) {
 			SStream ss;
 			SStream_Init(&ss);

 			// relative branches need to know the address & size of current insn
 			mci.insn_size = insn_size;
 			mci.address = offset;

 			if (handle->detail) {
 				// save all the information for non-detailed mode
 				mci.pub_insn.address = offset;
 				mci.pub_insn.size = insn_size;
 			}

 			handle->printer(&mci, &ss, handle->printer_info);

 			fill_insn(handle, insn, ss.buffer, &mci, handle->post_printer, buffer);

 			c++;
 			insn++;
 			buffer += insn_size;
 			size -= insn_size;
 			offset += insn_size;

 			if (c == count)
 				return c;
 		} else
 			// face a broken instruction? then we stop here
 			return c;
 	}

 	return c;
 }

 // dynamicly allocate memory to contain disasm insn
 // NOTE: caller must free() the allocated memory itself to avoid memory leaking
 size_t cs_disasm_dyn(csh ud, const uint8_t *buffer, size_t size, uint64_t offset, size_t count, cs_insn **insn)
 {
 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;
 	MCInst mci;
 	uint16_t insn_size;
 	size_t c = 0, f = 0;
 	cs_insn insn_cache[64];
 	void *total = NULL;
 	size_t total_size = 0;

 	if (!handle) {
 		// FIXME: how to handle this case:
 		// handle->errnum = CS_ERR_HANDLE;
 		return 0;
 	}

 	handle->errnum = CS_ERR_OK;

 	memset(insn_cache, 0, sizeof(insn_cache));

 	while (size > 0) {
 		MCInst_Init(&mci);
 		mci.detail = handle->detail;
 		mci.mode = handle->mode;

 		bool r = handle->disasm(ud, buffer, size, &mci, &insn_size, offset, handle->getinsn_info);
 		if (r) {
 			SStream ss;
 			SStream_Init(&ss);

 			// relative branches need to know the address & size of current insn
 			mci.insn_size = insn_size;
 			mci.address = offset;

 			if (handle->detail) {
 				// save all the information for non-detailed mode
 				mci.pub_insn.address = offset;
 				mci.pub_insn.size = insn_size;
 			}

 			handle->printer(&mci, &ss, handle->printer_info);

 			fill_insn(handle, &insn_cache[f], ss.buffer, &mci, handle->post_printer, buffer);

 			f++;

 			if (f == ARR_SIZE(insn_cache)) {
 				// resize total to contain newly disasm insns
 				total_size += sizeof(insn_cache);
 				void *tmp = realloc(total, total_size);
 				if (tmp == NULL) {	// insufficient memory
 					free(total);
 					handle->errnum = CS_ERR_MEM;
 					return 0;
 				}

 				total = tmp;
 				memcpy(total + total_size - sizeof(insn_cache), insn_cache, sizeof(insn_cache));
 				// reset f back to 0
 				f = 0;
 			}

 			c++;
 			buffer += insn_size;
 			size -= insn_size;
 			offset += insn_size;

 			if (count > 0 && c == count)
 				break;
 		} else	{
 			// encounter a broken instruction
 			// XXX: TODO: JOXEAN continue here
 			break;
 		}
 	}

 	if (f) {
 		// resize total to contain newly disasm insns
 		void *tmp = realloc(total, total_size + f * sizeof(insn_cache[0]));
 		if (tmp == NULL) {	// insufficient memory
 			free(total);
 			handle->errnum = CS_ERR_MEM;
 			return 0;
 		}

 		total = tmp;
 		memcpy(total + total_size, insn_cache, f * sizeof(insn_cache[0]));
 	}

 	*insn = total;

 	return c;
 }

 void cs_free(void *m)
 {
 	free(m);
 }

 // return friendly name of regiser in a string
 const char *cs_reg_name(csh ud, unsigned int reg)
 {
 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;

 	if (!handle || handle->reg_name == NULL) {
 		return NULL;
 	}

 	return handle->reg_name(ud, reg);
 }

 const char *cs_insn_name(csh ud, unsigned int insn)
 {
 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;

 	if (!handle || handle->insn_name == NULL) {
 		return NULL;
 	}

 	return handle->insn_name(ud, insn);
 }

 static bool arr_exist(unsigned char *arr, unsigned char max, unsigned int id)
 {
 	int i;

 	for (i = 0; i < max; i++) {
 		if (arr[i] == id)
 			return true;
 	}

 	return false;
 }

 bool cs_insn_group(csh handle, cs_insn *insn, unsigned int group_id)
 {
 	if (!handle)
 		return false;

 	return arr_exist(insn->groups, insn->groups_count, group_id);
 }

 bool cs_reg_read(csh handle, cs_insn *insn, unsigned int reg_id)
 {
 	if (!handle)
 		return false;

 	return arr_exist(insn->regs_read, insn->regs_read_count, reg_id);
 }

 bool cs_reg_write(csh handle, cs_insn *insn, unsigned int reg_id)
 {
 	if (!handle)
 		return false;

 	return arr_exist(insn->regs_write, insn->regs_write_count, reg_id);
 }

 int cs_op_count(csh ud, cs_insn *insn, unsigned int op_type)
 {
 	if (!ud)
 		return -1;

 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;
 	unsigned int count = 0, i;

 	handle->errnum = CS_ERR_OK;

 	switch (handle->arch) {
 		default:
 			handle->errnum = CS_ERR_HANDLE;
 			return -1;
 		case CS_ARCH_ARM:
 			for (i = 0; i < insn->arm.op_count; i++)
 				if (insn->arm.operands[i].type == op_type)
 					count++;
 			break;
 		case CS_ARCH_ARM64:
 			for (i = 0; i < insn->arm64.op_count; i++)
 				if (insn->arm64.operands[i].type == op_type)
 					count++;
 			break;
 		case CS_ARCH_X86:
 			for (i = 0; i < insn->x86.op_count; i++)
 				if (insn->x86.operands[i].type == op_type)
 					count++;
 			break;
 		case CS_ARCH_MIPS:
 			for (i = 0; i < insn->mips.op_count; i++)
 				if (insn->mips.operands[i].type == op_type)
 					count++;
 			break;
 	}

 	return count;
 }

 int cs_op_index(csh ud, cs_insn *insn, unsigned int op_type,
 		unsigned int post)
 {
 	if (!ud)
 		return -1;

 	cs_struct *handle = (cs_struct *)(uintptr_t)ud;
 	unsigned int count = 0, i;

 	handle->errnum = CS_ERR_OK;

 	switch (handle->arch) {
 		default:
 			handle->errnum = CS_ERR_HANDLE;
 			return -1;
 		case CS_ARCH_ARM:
 			for (i = 0; i < insn->arm.op_count; i++) {
 				if (insn->arm.operands[i].type == op_type)
 					count++;
 				if (count == post)
 					return i;
 			}
 			break;
 		case CS_ARCH_ARM64:
 			for (i = 0; i < insn->arm64.op_count; i++) {
 				if (insn->arm64.operands[i].type == op_type)
 					count++;
 				if (count == post)
 					return i;
 			}
 			break;
 		case CS_ARCH_X86:
 			for (i = 0; i < insn->x86.op_count; i++) {
 				if (insn->x86.operands[i].type == op_type)
 					count++;
 				if (count == post)
 					return i;
 			}
 			break;
 		case CS_ARCH_MIPS:
 			for (i = 0; i < insn->mips.op_count; i++) {
 				if (insn->mips.operands[i].type == op_type)
 					count++;
 				if (count == post)
 					return i;
 			}
 			break;
 	}

 	return -1;
 }
	/* Capstone Disassembler Engine */
	/* By Nguyen Anh Quynh <[email protected]>, 2013> */

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <capstone.h>

	#include "cs_priv.h"

	#include "MCRegisterInfo.h"

	#include "utils.h"

	void (arch_init[MAX_ARCH])(cs_struct ) = { NULL };
	cs_err (arch_option[MAX_ARCH]) (cs_struct, cs_opt_type, size_t value);

	unsigned int all_arch = 0;

	unsigned int cs_version(int major, int minor)
	{
	*major = CS_API_MAJOR;
	*minor = CS_API_MINOR;

	return (CS_API_MAJOR << 8) + CS_API_MINOR;
	}

	bool cs_support(cs_arch arch)
	{
	if (arch == CS_ARCH_ALL)
	return all_arch == ((1 << CS_ARCH_ARM) \| (1 << CS_ARCH_ARM64) \|
	(1 << CS_ARCH_MIPS) \| (1 << CS_ARCH_X86));

	return all_arch & (1 << arch);
	}

	cs_err cs_errno(csh handle)
	{
	if (!handle)
	return CS_ERR_CSH;

	cs_struct ud = (cs_struct )(uintptr_t)handle;

	return ud->errnum;
	}

	cs_err cs_open(cs_arch arch, cs_mode mode, csh *handle)
	{
	cs_struct *ud;

	ud = calloc(1, sizeof(*ud));
	if (!ud) {
	// memory insufficient
	return CS_ERR_MEM;
	}

	if (arch < CS_ARCH_MAX && arch_init[ud->arch]) {
	ud->errnum = CS_ERR_OK;
	ud->arch = arch;
	ud->mode = mode;
	ud->big_endian = mode & CS_MODE_BIG_ENDIAN;
	ud->reg_name = NULL;
	ud->detail = CS_OPT_ON; // by default break instruction into details

	arch_init[ud->arch](ud);
	} else {
	*handle = 0;
	return CS_ERR_ARCH;
	}

	*handle = (uintptr_t)ud;

	return CS_ERR_OK;
	}

	cs_err cs_close(csh handle)
	{
	if (!handle)
	return CS_ERR_CSH;

	cs_struct ud = (cs_struct )(uintptr_t)handle;

	switch (ud->arch) {
	case CS_ARCH_X86:
	break;
	case CS_ARCH_ARM:
	case CS_ARCH_MIPS:
	case CS_ARCH_ARM64:
	free(ud->printer_info);
	break;
	default: // unsupported architecture
	return CS_ERR_HANDLE;
	}

	memset(ud, 0, sizeof(*ud));
	free(ud);

	return CS_ERR_OK;
	}

	#define MIN(x, y) ((x) < (y) ? (x) : (y))

	// fill insn with mnemonic & operands info
	static void fill_insn(cs_struct handle, cs_insn insn, char buffer, MCInst mci,
	PostPrinter_t printer, const uint8_t *code)
	{
	if (handle->detail) {
	memcpy(insn, &mci->pub_insn, sizeof(*insn));

	// fill the instruction bytes
	memcpy(insn->bytes, code, MIN(sizeof(insn->bytes), insn->size));

	} else {
	insn->address = mci->address;
	insn->size = mci->insn_size;
	}

	// map internal instruction opcode to public insn ID
	if (handle->insn_id)
	handle->insn_id(insn, MCInst_getOpcode(mci), handle->detail);

	// alias instruction might have ID saved in OpcodePub
	if (MCInst_getOpcodePub(mci))
	insn->id = MCInst_getOpcodePub(mci);

	// post printer handles some corner cases (hacky)
	if (printer)
	printer((csh)handle, insn, buffer);

	// fill in mnemonic & operands
	// find first space or tab
	char *sp = buffer;
	for (sp = buffer; *sp; sp++)
	if (sp == ' '\|\|sp == '\t')
	break;
	if (*sp) {
	*sp = '\0';
	// find the next non-space char
	sp++;
	for (; ((sp == ' ') \|\| (sp == '\t')); sp++);
	strncpy(insn->op_str, sp, sizeof(insn->op_str) - 1);
	insn->op_str[sizeof(insn->op_str) - 1] = '\0';
	} else
	insn->op_str[0] = '\0';

	strncpy(insn->mnemonic, buffer, sizeof(insn->mnemonic) - 1);
	insn->mnemonic[sizeof(insn->mnemonic) - 1] = '\0';
	}

	cs_err cs_option(csh ud, cs_opt_type type, size_t value)
	{
	cs_struct handle = (cs_struct )(uintptr_t)ud;
	if (!handle)
	return CS_ERR_CSH;

	if (type == CS_OPT_DETAIL) {
	handle->detail = value;
	return CS_ERR_OK;
	}

	return arch_option[handle->arch](handle, type, value);
	}

	size_t cs_disasm(csh ud, const uint8_t buffer, size_t size, uint64_t offset, size_t count, cs_insn insn)
	{
	cs_struct handle = (cs_struct )(uintptr_t)ud;
	MCInst mci;
	uint16_t insn_size;
	size_t c = 0;

	if (!handle) {
	// FIXME: handle this case?
	// handle->errnum = CS_ERR_HANDLE;
	return 0;
	}

	handle->errnum = CS_ERR_OK;
	memset(insn, 0, count * sizeof(*insn));

	while (size > 0) {
	MCInst_Init(&mci);
	mci.detail = handle->detail;
	mci.mode = handle->mode;

	bool r = handle->disasm(ud, buffer, size, &mci, &insn_size, offset, handle->getinsn_info);
	if (r) {
	SStream ss;
	SStream_Init(&ss);

	// relative branches need to know the address & size of current insn
	mci.insn_size = insn_size;
	mci.address = offset;

	if (handle->detail) {
	// save all the information for non-detailed mode
	mci.pub_insn.address = offset;
	mci.pub_insn.size = insn_size;
	}

	handle->printer(&mci, &ss, handle->printer_info);

	fill_insn(handle, insn, ss.buffer, &mci, handle->post_printer, buffer);

	c++;
	insn++;
	buffer += insn_size;
	size -= insn_size;
	offset += insn_size;

	if (c == count)
	return c;
	} else
	// face a broken instruction? then we stop here
	return c;
	}

	return c;
	}

	// dynamicly allocate memory to contain disasm insn
	// NOTE: caller must free() the allocated memory itself to avoid memory leaking
	size_t cs_disasm_dyn(csh ud, const uint8_t buffer, size_t size, uint64_t offset, size_t count, cs_insn *insn)
	{
	cs_struct handle = (cs_struct )(uintptr_t)ud;
	MCInst mci;
	uint16_t insn_size;
	size_t c = 0, f = 0;
	cs_insn insn_cache[64];
	void *total = NULL;
	size_t total_size = 0;

	if (!handle) {
	// FIXME: how to handle this case:
	// handle->errnum = CS_ERR_HANDLE;
	return 0;
	}

	handle->errnum = CS_ERR_OK;

	memset(insn_cache, 0, sizeof(insn_cache));

	while (size > 0) {
	MCInst_Init(&mci);
	mci.detail = handle->detail;
	mci.mode = handle->mode;

	bool r = handle->disasm(ud, buffer, size, &mci, &insn_size, offset, handle->getinsn_info);
	if (r) {
	SStream ss;
	SStream_Init(&ss);

	// relative branches need to know the address & size of current insn
	mci.insn_size = insn_size;
	mci.address = offset;

	if (handle->detail) {
	// save all the information for non-detailed mode
	mci.pub_insn.address = offset;
	mci.pub_insn.size = insn_size;
	}

	handle->printer(&mci, &ss, handle->printer_info);

	fill_insn(handle, &insn_cache[f], ss.buffer, &mci, handle->post_printer, buffer);

	f++;

	if (f == ARR_SIZE(insn_cache)) {
	// resize total to contain newly disasm insns
	total_size += sizeof(insn_cache);
	void *tmp = realloc(total, total_size);
	if (tmp == NULL) { // insufficient memory
	free(total);
	handle->errnum = CS_ERR_MEM;
	return 0;
	}

	total = tmp;
	memcpy(total + total_size - sizeof(insn_cache), insn_cache, sizeof(insn_cache));
	// reset f back to 0
	f = 0;
	}

	c++;
	buffer += insn_size;
	size -= insn_size;
	offset += insn_size;

	if (count > 0 && c == count)
	break;
	} else {
	// encounter a broken instruction
	// XXX: TODO: JOXEAN continue here
	break;
	}
	}

	if (f) {
	// resize total to contain newly disasm insns
	void tmp = realloc(total, total_size + f sizeof(insn_cache[0]));
	if (tmp == NULL) { // insufficient memory
	free(total);
	handle->errnum = CS_ERR_MEM;
	return 0;
	}

	total = tmp;
	memcpy(total + total_size, insn_cache, f * sizeof(insn_cache[0]));
	}

	*insn = total;

	return c;
	}

	void cs_free(void *m)
	{
	free(m);
	}

	// return friendly name of regiser in a string
	const char *cs_reg_name(csh ud, unsigned int reg)
	{
	cs_struct handle = (cs_struct )(uintptr_t)ud;

	if (!handle \|\| handle->reg_name == NULL) {
	return NULL;
	}

	return handle->reg_name(ud, reg);
	}

	const char *cs_insn_name(csh ud, unsigned int insn)
	{
	cs_struct handle = (cs_struct )(uintptr_t)ud;

	if (!handle \|\| handle->insn_name == NULL) {
	return NULL;
	}

	return handle->insn_name(ud, insn);
	}

	static bool arr_exist(unsigned char *arr, unsigned char max, unsigned int id)
	{
	int i;

	for (i = 0; i < max; i++) {
	if (arr[i] == id)
	return true;
	}

	return false;
	}

	bool cs_insn_group(csh handle, cs_insn *insn, unsigned int group_id)
	{
	if (!handle)
	return false;

	return arr_exist(insn->groups, insn->groups_count, group_id);
	}

	bool cs_reg_read(csh handle, cs_insn *insn, unsigned int reg_id)
	{
	if (!handle)
	return false;

	return arr_exist(insn->regs_read, insn->regs_read_count, reg_id);
	}

	bool cs_reg_write(csh handle, cs_insn *insn, unsigned int reg_id)
	{
	if (!handle)
	return false;

	return arr_exist(insn->regs_write, insn->regs_write_count, reg_id);
	}

	int cs_op_count(csh ud, cs_insn *insn, unsigned int op_type)
	{
	if (!ud)
	return -1;

	cs_struct handle = (cs_struct )(uintptr_t)ud;
	unsigned int count = 0, i;

	handle->errnum = CS_ERR_OK;

	switch (handle->arch) {
	default:
	handle->errnum = CS_ERR_HANDLE;
	return -1;
	case CS_ARCH_ARM:
	for (i = 0; i < insn->arm.op_count; i++)
	if (insn->arm.operands[i].type == op_type)
	count++;
	break;
	case CS_ARCH_ARM64:
	for (i = 0; i < insn->arm64.op_count; i++)
	if (insn->arm64.operands[i].type == op_type)
	count++;
	break;
	case CS_ARCH_X86:
	for (i = 0; i < insn->x86.op_count; i++)
	if (insn->x86.operands[i].type == op_type)
	count++;
	break;
	case CS_ARCH_MIPS:
	for (i = 0; i < insn->mips.op_count; i++)
	if (insn->mips.operands[i].type == op_type)
	count++;
	break;
	}

	return count;
	}

	int cs_op_index(csh ud, cs_insn *insn, unsigned int op_type,
	unsigned int post)
	{
	if (!ud)
	return -1;

	cs_struct handle = (cs_struct )(uintptr_t)ud;
	unsigned int count = 0, i;

	handle->errnum = CS_ERR_OK;

	switch (handle->arch) {
	default:
	handle->errnum = CS_ERR_HANDLE;
	return -1;
	case CS_ARCH_ARM:
	for (i = 0; i < insn->arm.op_count; i++) {
	if (insn->arm.operands[i].type == op_type)
	count++;
	if (count == post)
	return i;
	}
	break;
	case CS_ARCH_ARM64:
	for (i = 0; i < insn->arm64.op_count; i++) {
	if (insn->arm64.operands[i].type == op_type)
	count++;
	if (count == post)
	return i;
	}
	break;
	case CS_ARCH_X86:
	for (i = 0; i < insn->x86.op_count; i++) {
	if (insn->x86.operands[i].type == op_type)
	count++;
	if (count == post)
	return i;
	}
	break;
	case CS_ARCH_MIPS:
	for (i = 0; i < insn->mips.op_count; i++) {
	if (insn->mips.operands[i].type == op_type)
	count++;
	if (count == post)
	return i;
	}
	break;
	}

	return -1;
	}