parse_chip8_pseudo.c

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// SPDX-FileCopyrightText: 2019 Vasilij Schneidermann <mail@vasilij.de>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_lib.h>
#include <rz_util.h>
#include <rz_flag.h>
#include <rz_analysis.h>
#include <rz_parse.h>
 
#define MAXARGS 4
#define BUFSIZE 64
 
static void concat(char *buf, size_t len, char **args) {
    char *arg;
    char *dest = buf;
    int arg_len;
 
    while ((arg = *args++)) {
        if (snprintf(dest, len, "%s", arg) >= len) {
            break;
        }
        arg_len = strlen(arg);
        dest += arg_len;
        len -= arg_len;
    }
}
 
static int replace(int argc, char *argv[], char *newstr, size_t len) {
    int i;
    struct {
        char *op;
        char **res;
    } ops[] = {
        { "add", (char *[]){ argv[1], " += ", argv[2], NULL } },
        { "and", (char *[]){ argv[1], " &= ", argv[2], NULL } },
        { "cls", (char *[]){ "clear_screen()", NULL } },
        { "drw", (char *[]){ "draw(", argv[1], ", ", argv[2], ", ", argv[3], ")", NULL } },
        { "exit", (char *[]){ "exit()", NULL } },
        { "high", (char *[]){ "high_res()", NULL } },
        { "jp", (char *[]){ "goto ", argv[1], NULL } },
        { "ld", (char *[]){ argv[1], " = ", argv[2], NULL } },
        { "low", (char *[]){ "low_res()", NULL } },
        { "or", (char *[]){ argv[1], " |= ", argv[2], NULL } },
        { "rnd", (char *[]){ argv[1], " = random(256) & ", argv[2], NULL } },
        { "scd", (char *[]){ "scroll_down(", argv[1], ")", NULL } },
        { "scl", (char *[]){ "scroll_left()", NULL } },
        { "scr", (char *[]){ "scroll_right()", NULL } },
        { "se", (char *[]){ "skip_next_instr if ", argv[1], " == ", argv[2], NULL } },
        { "shl", (char *[]){ argv[1], " <<= 1", NULL } },
        { "shr", (char *[]){ argv[1], " >>= 1", NULL } },
        { "sknp", (char *[]){ "skip_next_instr if !key_pressed(", argv[1], ")", NULL } },
        { "skp", (char *[]){ "skip_next_instr if key_pressed(", argv[1], ")", NULL } },
        { "sne", (char *[]){ "skip_next_instr if ", argv[1], " != ", argv[2], NULL } },
        { "sub", (char *[]){ argv[1], " -= ", argv[2], NULL } },
        { "subn", (char *[]){ argv[1], " = ", argv[2], " - ", argv[1], NULL } },
        { "xor", (char *[]){ argv[1], " ^= ", argv[2], NULL } },
        { NULL }
    };
 
    for (i = 0; ops[i].op; i++) {
        if (!strcmp(ops[i].op, argv[0]) && newstr) {
            concat(newstr, len, ops[i].res);
            return true;
        }
    }
 
    return false;
}
 
static int tokenize(const char *in, char *out[]) {
    int len = strlen(in), count = 0, i = 0, tokenlen = 0, seplen = 0;
    char *token, *buf = (char *)in;
    const char *tokcharset = ", \t\n";
 
    while (i < len) {
        tokenlen = strcspn(buf, tokcharset);
        token = calloc(tokenlen + 1, sizeof(char));
        memcpy(token, buf, tokenlen);
        out[count] = token;
        i += tokenlen;
        buf += tokenlen;
        count++;
 
        seplen = strspn(buf, tokcharset);
        i += seplen;
        buf += seplen;
    }
 
    return count;
}
 
static bool parse(RzParse *p, const char *data, RzStrBuf *sb) {
    int i;
    char str[1024] = { 0 };
    char *argv[MAXARGS] = { NULL, NULL, NULL, NULL };
    int argc = tokenize(data, argv);
 
    if (!replace(argc, argv, str, BUFSIZE)) {
        strcpy(str, data);
    }
 
    for (i = 0; i < MAXARGS; i++) {
        free(argv[i]);
    }
    rz_strbuf_set(sb, str);
 
    return true;
}
 
RzParsePlugin rz_parse_plugin_chip8_pseudo = {
    .name = "chip8.pseudo",
    .desc = "chip8 pseudo syntax",
    .parse = parse,
};
 
#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
    .type = RZ_LIB_TYPE_PARSE,
    .data = &rz_parse_plugin_chip8_pseudo,
    .version = RZ_VERSION
};
#endif