test_customized_mnem.c

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/* Capstone Disassembly Engine */
/* By Nguyen Anh Quynh <aquynh@gmail.com>, 2015 */
 
// This sample code demonstrates the option CS_OPT_MNEMONIC
// to customize instruction mnemonic.
 
#include <stdio.h>
#include <stdlib.h>
 
#include <capstone/platform.h>
#include <capstone/capstone.h>
 
#define X86_CODE32 "\x75\x01"
 
// Print out the input code in hexadecimal format
static void print_string_hex(unsigned char *str, size_t len)
{
        unsigned char *c;
 
        for (c = str; c < str + len; c++) {
                printf("%02x ", *c & 0xff);
        }
        printf("\t");
}
 
// Print one instruction
static void print_insn(csh handle)
{
        cs_insn *insn;
        size_t count;
        
        count = cs_disasm(handle, (const uint8_t *)X86_CODE32, sizeof(X86_CODE32) - 1, 0x1000, 1, &insn);
        if (count) {
                print_string_hex((unsigned char *)X86_CODE32, sizeof(X86_CODE32) - 1);
                printf("\t%s\t%s\n", insn[0].mnemonic, insn[0].op_str); 
                // Free memory allocated by cs_disasm()
                cs_free(insn, count);
        } else {
                printf("ERROR: Failed to disasm given code!\n");
                abort();
        }
}
 
static void test()
{
        csh handle;
        cs_err err;
        // Customize mnemonic JNE to "jnz"
        cs_opt_mnem my_mnem = { X86_INS_JNE, "jnz" };
        // Set .mnemonic to NULL to reset to default mnemonic
        cs_opt_mnem default_mnem = { X86_INS_JNE, NULL };
 
        err = cs_open(CS_ARCH_X86, CS_MODE_32, &handle);
        if (err) {
                printf("Failed on cs_open() with error returned: %u\n", err);
                abort();
        }
 
        // 1. Print out the instruction in default setup.
        printf("Disassemble X86 code with default instruction mnemonic\n");
        print_insn(handle);
 
        // Customized mnemonic JNE to JNZ using CS_OPT_MNEMONIC option
        printf("\nNow customize engine to change mnemonic from 'JNE' to 'JNZ'\n");
        cs_option(handle, CS_OPT_MNEMONIC, (size_t)&my_mnem);
 
        // 2. Now print out the instruction in newly customized setup.
        print_insn(handle);
 
        // Reset engine to use the default mnemonic of JNE
        printf("\nReset engine to use the default mnemonic\n");
        cs_option(handle, CS_OPT_MNEMONIC, (size_t)&default_mnem);
 
        // 3. Now print out the instruction in default setup.
        print_insn(handle);
 
        // Done
        cs_close(&handle);
}
 
int main()
{
        test();
 
        return 0;
}