asm_bf.c

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// SPDX-FileCopyrightText: 2009-2021 pancake <pancake@nopcode.org>
// SPDX-FileCopyrightText: 2009-2021 nibble <nibble.ds@gmail.com>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_asm.h>
 
static int disassemble(RzAsm *a, RzAsmOp *op, const ut8 *buf, int len) {
    const char *buf_asm = "invalid";
    switch (*buf) {
    case '[':
        buf_asm = "while [ptr]";
        break;
    case ']':
        buf_asm = "loop";
        break;
    case '>':
        buf_asm = "inc ptr";
        break;
    case '<':
        buf_asm = "dec ptr";
        break;
    case '+':
        buf_asm = "inc [ptr]";
        break;
    case '-':
        buf_asm = "dec [ptr]";
        break;
    case ',':
        buf_asm = "in [ptr]";
        break;
    case '.':
        buf_asm = "out [ptr]";
        break;
    case 0xff:
    case 0x00:
        buf_asm = "trap";
        break;
    default:
        buf_asm = "nop";
        break;
    }
 
    rz_strbuf_set(&op->buf_asm, buf_asm);
    op->size = 1;
    return op->size;
}
 
static bool _write_asm(RzAsmOp *op, int value, int n) {
    ut8 *opbuf = malloc(n);
    if (opbuf == NULL) {
        return true;
    }
    memset(opbuf, value, n);
    rz_strbuf_setbin(&op->buf, opbuf, n);
    free(opbuf);
    return false;
}
 
static int assemble(RzAsm *a, RzAsmOp *op, const char *buf) {
    int n = 0;
    if (buf[0] && buf[1] == ' ') {
        buf += 2;
    }
    const char *arg = strchr(buf, ',');
    const char *ref = strchr(buf, '[');
    bool write_err = false;
    if (arg) {
        n = atoi(arg + 1);
    } else {
        n = 1;
    }
    if (!strncmp(buf, "trap", 4)) {
        write_err = _write_asm(op, 0xcc, n);
    } else if (!strncmp(buf, "nop", 3)) {
        write_err = _write_asm(op, 0x90, n);
    } else if (!strncmp(buf, "inc", 3)) {
        char ch = ref ? '+' : '>';
        n = 1;
        write_err = _write_asm(op, ch, n);
    } else if (!strncmp(buf, "dec", 3)) {
        char ch = ref ? '-' : '<';
        n = 1;
        write_err = _write_asm(op, ch, n);
    } else if (!strncmp(buf, "sub", 3)) {
        char ch = ref ? '-' : '<';
        write_err = _write_asm(op, ch, n);
    } else if (!strncmp(buf, "add", 3)) {
        char ch = ref ? '+' : '>';
        write_err = _write_asm(op, ch, n);
    } else if (!strncmp(buf, "while", 5)) {
        n = 1;
        write_err = _write_asm(op, '[', 1);
    } else if (!strncmp(buf, "loop", 4)) {
        n = 1;
        write_err = _write_asm(op, ']', 1);
    } else if (!strncmp(buf, "in", 2)) {
        write_err = _write_asm(op, ',', n);
    } else if (!strncmp(buf, "out", 3)) {
        write_err = _write_asm(op, '.', n);
    } else {
        n = 0;
    }
    if (write_err) {
        return 0;
    }
    return n;
}
 
RzAsmPlugin rz_asm_plugin_bf = {
    .name = "bf",
    .author = "pancake, nibble",
    .version = "4.0.0",
    .arch = "bf",
    .license = "LGPL3",
    .bits = 16 | 32 | 64,
    .endian = RZ_SYS_ENDIAN_NONE,
    .desc = "Brainfuck",
    .disassemble = &disassemble,
    .assemble = &assemble
};
 
#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
    .type = RZ_LIB_TYPE_ASM,
    .data = &rz_asm_plugin_bf,
    .version = RZ_VERSION
};
#endif