/* radare - LGPL - Copyright 2009-2024 - nibble, pancake */

#include <r_asm.h>

// 16 bit examples
//    0x0001f3a4      9a67620eca       call word 0xca0e:0x6267
//    0x0001f41c      eabe76de12       jmp word 0x12de:0x76be [2]
//    0x0001f56a      ea7ed73cd3       jmp word 0xd33c:0xd77e [6]

// XXX seems like '(#)' doesnt works.. so it needs to be '( # )'
// this is a bug somewhere else
static char *replace(int argc, char *argv[]) {
#define MAXPSEUDOOPS 10
	int i, j, d;
	char ch;
	struct {
		const char *op;
		const char *str;
		int args[MAXPSEUDOOPS];  // XXX can't use flex arrays, all unused will be 0
	} ops[] = {
		{ "adc",  "# += #", {1, 2}},
		{ "add",  "# += #", {1, 2}},
		{ "and",  "# &= #", {1, 2}},
		{ "andn", "# = (~#) & #", {1, 2, 3}},
		{ "ret", "return", {0}},
		{ "iret", "return", {0}},
		{ "endbr64", "", {0}},
		{ "endbr", "", {0}},
		{ "call", "# ()", {1}},
		{ "bextr", "# = bextr(#, #)", {1, 2, 3}},
		{ "blsi", "# = # & -#", {1, 2, 2}},
		{ "blsr", "# = # & (# - 1)", {1, 2, 2}},
		{ "blsmsk", "# = # ^ (# - 1)", {1, 2, 2}},
		{ "cmove", "if (!v) # = #", {1, 2}},
		{ "cmovl","if (v < 0) # = #", {1, 2}},
		{ "cmp", "v = # - #", {1, 2}},
		{ "cmpsq", "v = # - #", {1, 2}},
		{ "cmpsb", "while (CX != 0) { v = *(DS*16 + SI) - *(ES*16 + DI); SI++; DI++; CX--; if (!v) break; }", {0}},
		{ "cmpsw", "while (CX != 0) { v = *(DS*16 + SI) - *(ES*16 + DI); SI+=4; DI+=4; CX--; if (!v) break; }", {0}},
		{ "dec",  "#--", {1}},
		{ "div",  "# /= #", {1, 2}},
		{ "fabs",  "abs(#)", {1}},
		{ "fadd",  "# = # + #", {1, 1, 2}},
		{ "fcomp",  "v = # - #", {1, 2}},
		{ "fcos",  "# = cos(#)", {1, 1}},
		{ "fdiv",  "# = # / #", {1, 1, 2}},
		{ "fiadd",  "# = # / #", {1, 1, 2}},
		{ "ficom",  "v = # - #", {1, 2}},
		{ "fidiv",  "# = # / #", {1, 1, 2}},
		{ "fidiv",  "# = # * #", {1, 1, 2}},
		{ "fisub",  "# = # - #", {1, 1, 2}},
		{ "fnul",  "# = # * #", {1, 1, 2}},
		{ "fnop",  " ", {0}},
		{ "frndint",  "# = (int) #", {1, 1}},
		{ "fsin",  "# = sin(#)", {1, 1}},
		{ "fsqrt",  "# = sqrt(#)", {1, 1}},
		{ "fsub",  "# = # - #", {1, 1, 2}},
		{ "fxch",  "#,# = #,#", {1, 2, 2, 1}},
		{ "idiv",  "# /= #", {1, 2}},
		{ "imul",  "# = # * #", {1, 2, 3}},
		{ "in",   "# = io[ # ]", {1, 2}},
		{ "inc",  "#++", {1}},
		{ "ja", "if (((unsigned) v) > 0) goto #", {1}},
		{ "jb", "if (((unsigned) v) < 0) goto #", {1}},
		{ "jbe", "if (((unsigned) v) <= 0) goto #", {1}},
		{ "jae", "if (((unsigned) v) >= 0) goto loc_#", {1}},
		{ "je", "if (!v) goto loc_#", {1}},
		{ "jz", "if (!v) goto loc_#", {1}},
		{ "jg", "if (v > 0) goto loc_#", {1}},
		{ "jge", "if (v >= 0) goto loc_#", {1}},
		{ "jl", "if (v < 0) goto loc_#", {1}},
		{ "jle", "if (v <= 0) goto loc_#", {1}},
		{ "jmp",  "goto loc_#", {1}},
		{ "jne", "if (v) goto loc_#", {1}},
		{ "jno", "if (!overflow) goto loc_#", {1}},
		{ "jnp", "if (!parity) goto loc_#", {1}},
		{ "jns", "if (v >= 0) goto loc_#", {1}},
		{ "jo", "if (overflow) goto loc_#", {1}},
		{ "jp", "if (parity) goto loc_#", {1}},
		{ "js", "if (v < 0) goto loc_#", {1}},
		{ "leav",  ";", {0}},
		{ "lea",  "# = #", {1, 2}},
		{ "mov",  "# = #", {1, 2}},
		{ "movabs", "# = #", {1, 2}},
		{ "cmovne", "if (!zf) # = #", {1, 2}},
		{ "cmove", "if (zf) # = #", {1, 2}},
		{ "movq",  "# = #", {1, 2}},
		{ "movaps",  "# = #", {1, 2}},
		{ "movups",  "# = #", {1, 2}},
		{ "movsd",  "# = #", {1, 2}},
		{ "movsx","# = #", {1, 2}},
		{ "movsxd","# = #", {1, 2}},
		{ "movzx", "# = #", {1, 2}},
		{ "movntdq", "# = #", {1, 2}},
		{ "movnti", "# = #", {1, 2}},
		{ "movntpd", "# = #", {1, 2}},
		{ "pcmpeqb", "# == #", {1, 2}},
		{ "movdqu", "# = #", {1, 2}},
		{ "movdqa", "# = #", {1, 2}},
		{ "pextrb", "# = (byte) # [ # ]", {1, 2, 3}},
		{ "palignr", "# = # align #", {1, 2, 3}},
		{ "pxor", "# ^= #", {1, 2}},
		{ "xorps", "# ^= #", {1, 2}},
		{ "mul",  "# = # * #", {1, 2, 3}},
		{ "mulss",  "# = # * #", {1, 2, 3}},
		{ "neg",  "# ~= #", {1, 1}},
		{ "nop",  "", {0}},
		{ "not",  "# = !#", {1, 1}},
		{ "or",   "# |= #", {1, 2}},
		{ "out",  "io[ # ] = #", {1, 2}},
		{ "pop",  "# = pop ()", {1}},
		{ "pushf", "push (cpuflags)", {0}},
		{ "push", "push (#)", {1}},
		{ "sal",  "# <<= #", {1, 2}},
		{ "sar",  "# >>= #", {1, 2}},
		{ "sete",  "# = v == 0", {1}},
		{ "setz",  "# = v == 0", {1}},
		{ "setne",  "# = v != 0", {1}},
		{ "setnz",  "# = v != 0", {1}},
		{ "shl",  "# <<<= #", {1, 2}},
		{ "shld",  "# <<<= #", {1, 2}},
		{ "sbb",  "# = # - #", {1, 1, 2}},
		{ "shr",  "# >>>= #", {1, 2}},
		{ "shlr",  "# >>>= #", {1, 2}},
		//{ "strd",  "# = # - #", {1, 2, 3}},
		{ "sub",  "# -= #", {1, 2}},
		{ "swap", "v = #; # = #; # = v", {1, 1, 2, 2}},
		{ "test", "v = # & #", {1, 2}},
		{ "tzcnt", "# = __builtin_ctz(#)", {1, 2}},
		{ "xchg",  "#,# = #,#", {1, 2, 2, 1}},
		{ "xadd",  "#,# = #,# + #", {1, 2, 2, 1, 2}},
		{ "xor",  "# ^= #", {1, 2}},
		{ NULL }
	};
	if (argc == 1) {
		if (argv[0][0] && !argv[0][1]) {
			return strdup ("");
		}
	}

	if (argc > 2 && !strcmp (argv[0], "xor")) {
		if (!strcmp (argv[1], argv[2])) {
			argv[0] = "mov";
			argv[2] = "0";
		}
	}
	RStrBuf *sb = r_strbuf_new ("");
	for (i = 0; ops[i].op; i++) {
		if (strcmp (ops[i].op, argv[0])) {
			continue;
		}
		d = 0;
		j = 0;
		ch = ops[i].str[j];
		for (j = 0; ch != '\0'; j++) {
			ch = ops[i].str[j];
			if (ch == '#') {
				if (d >= MAXPSEUDOOPS) {
					// XXX Shouldn't ever happen...
					continue;
				}
				int idx = ops[i].args[d++];
				if (idx <= 0) {
					// XXX Shouldn't ever happen...
					continue;
				}
				const char *w = argv[idx];
				if (w) {
					r_strbuf_append (sb, w);
				}
			} else {
				r_strbuf_append_n (sb, &ch, 1);
			}
		}
		return r_strbuf_drain (sb);
	}

	for (i = 0; i < argc; i++) {
		r_strbuf_append (sb, argv[i]);
		r_strbuf_append (sb, (i == argc - 1)? "": " ");
	}
	return r_strbuf_drain (sb);
}

static char *parse(RAsmPluginSession *aps, const char *data) {
	RParse *p = aps->rasm->parse;
	char w0[256], w1[256], w2[256], w3[256];
	int i;
	size_t len = strlen (data);
	int sz = 32;
	char *ptr, *optr, *end;
	if (len >= sizeof (w0) || sz >= sizeof (w0)) {
		return NULL;
	}
	// strdup can be slow here :?
	char *buf = strdup (data);
	if (!buf) {
		return NULL;
	}
	*w0 = *w1 = *w2 = *w3 = '\0';
	if (strchr (data, '(')) {
		// avoid double-pseudo calls
		free (buf);
		return NULL;
	}
	char *str = NULL;
	if (*buf) {
		end = buf + strlen (buf);
		ptr = strchr (buf, '(');
		if (!ptr) {
			ptr = strchr (buf, ' ');
			if (!ptr) {
				ptr = strchr (buf, '\t');
				if (!ptr) {
					ptr = end;
				}
			}
		}
		bool par = (ptr != buf && *ptr == '(');
		for (; ptr < end; ptr++) {
			if (*ptr != ' ') {
				if (*ptr == ')') {
					ptr--;
				}
				break;
			}
		}
		int delta = 1;
		if (par) {
			delta = 0;
			ptr++;
		}
		r_str_ncpy (w0, buf, R_MIN (ptr - buf + delta, sizeof (w0)));
		r_str_trim (w0);
		if (par) {
			ptr--;
		}
		r_str_ncpy (w1, ptr, R_MIN (end - ptr + 1, sizeof (w1)));
		optr = ptr;
		ptr = strchr (ptr, ',');
		if (ptr) {
			*ptr++ = '\0';
			for (ptr++; ptr < end ; ptr++) {
				if (*ptr != ')' && *ptr != ' ') {
					// ptr++;
					break;
				}
			}
			r_str_ncpy (w1, optr, sizeof (w1));
			r_str_ncpy (w2, ptr, sizeof (w2));
			optr = ptr;
			ptr = strchr (ptr, ',');
			if (ptr) {
				*ptr = '\0';
				ptr = (char *)r_str_trim_head_ro (ptr + 1);
				r_str_ncpy (w2, optr, sizeof (w2));
				r_str_ncpy (w3, ptr, sizeof (w3));
			}
		}
	}
	char *wa[] = { w0, w1, w2, w3 };
	int nw = 0;
	for (i = 0; i < 4; i++) {
		if (wa[i][0] != '\0') {
			nw++;
		}
	}
	/* TODO: interpretation of memory location fails*/
	// ensure imul & mul interpretations works
	if (strstr (w0, "mul")) {
		if (nw == 2) {
			r_str_ncpy (wa[3], wa[1], sizeof (w3));
			switch (wa[3][0]) {
			case 'q':
			case 'r': //qword, r..
				r_str_ncpy (wa[1], "rax", sizeof (w1));
				r_str_ncpy (wa[2], "rax", sizeof (w2));
				break;
			case 'd':
			case 'e': //dword, e..
				if (strlen (wa[3]) > 2) {
					r_str_ncpy (wa[1], "eax", sizeof (w1));
					r_str_ncpy (wa[2], "eax", sizeof (w2));
					break;
				}
			default : // .x, .p, .i or word
				if (wa[3][1] == 'x' || wa[3][1] == 'p' || \
					wa[3][1] == 'i' || wa[3][0] == 'w') {
					r_str_ncpy (wa[1], "ax", sizeof (w1));
					r_str_ncpy (wa[2], "ax", sizeof (w2));
				} else { // byte and lowest 8 bit registers
					r_str_ncpy (wa[1], "al", sizeof (w1));
					r_str_ncpy (wa[2], "al", sizeof (w2));
				}
			}
		} else if (nw == 3) {
			r_str_ncpy (wa[3], wa[2], sizeof (w3));
			r_str_ncpy (wa[2], wa[1], sizeof (w2));
		}
		str = replace (nw, wa);
	} else if (strstr (w0, "lea")) {
		r_str_replace_char (w2, '[', 0);
		r_str_replace_char (w2, ']', 0);
		str = replace (nw, wa);
	} else if (R_STR_CMP_ANY (w1, "rax", "eax", "ax", "ah", "al") && !p->retleave_asm) {
		p->retleave_asm = r_str_newf ("return %s", !strcmp (w0, "mov")? w2: w1);
		str = replace (nw, wa);
	} else if (strstr (w0, "ret") && p->retleave_asm) {
		str = strdup (p->retleave_asm);
		R_FREE (p->retleave_asm);
	} else {
		R_FREE (p->retleave_asm);
		str = replace (nw, wa);
	}
	if (str) {
		str = r_str_fixspaces (str);
	}
	free (buf);
	return str;
}

static void parse_localvar(RAsm *a, char *newstr, size_t newstr_len, const char *var, const char *reg, char sign, char *ireg, bool att) {
	RParse *p = a->parse;
	RStrBuf *sb = r_strbuf_new ("");
	if (att) {
		if (p->localvar_only) {
			if (ireg) {
				r_strbuf_setf (sb, "(%%%s)", ireg);
			}
			snprintf (newstr, newstr_len - 1, "%s%s", var, r_strbuf_get (sb));
		} else {
			if (ireg) {
				r_strbuf_setf (sb, ", %%%s", ireg);
			}
			snprintf (newstr, newstr_len - 1, "%s(%%%s%s)", var, reg, r_strbuf_get (sb));
		}
	} else {
		if (ireg) {
			r_strbuf_setf (sb, " + %s", ireg);
		}
		if (p->localvar_only) {
			snprintf (newstr, newstr_len - 1, "%s%s", var, r_strbuf_get (sb));
		} else {
			snprintf (newstr, newstr_len - 1, "%s%s %c %s", reg, r_strbuf_get (sb), sign, var);
		}
	}
	r_strbuf_free (sb);
}

static void mk_reg_str(const char *regname, int delta, bool sign, bool att, char *ireg, char *dest, int len) {
	RStrBuf *sb = r_strbuf_new ("");
	if (att) {
		if (ireg) {
			r_strbuf_setf (sb, ", %%%s", ireg);
		}
		if (delta == 0) {
			snprintf (dest, len - 1, "(%%%s%s)", regname, r_strbuf_get (sb));
		} else if (delta < 10) {
			snprintf (dest, len - 1, "%s%d(%%%s%s)", sign ? "" : "-", delta, regname, r_strbuf_get (sb));
		} else {
			snprintf (dest, len - 1, "%s0x%x(%%%s%s)", sign ? "" : "-", delta, regname, r_strbuf_get (sb));
		}
	} else {
		if (ireg) {
			r_strbuf_setf (sb, " + %s", ireg);
		}
		if (delta == 0) {
			snprintf (dest, len - 1, "%s%s", regname, r_strbuf_get (sb));
		} else if (delta < 10) {
			snprintf (dest, len - 1, "%s%s %c %d", regname, r_strbuf_get (sb), sign ? '+':'-', delta);
		} else {
			snprintf (dest, len - 1, "%s%s %c 0x%x", regname, r_strbuf_get (sb), sign ? '+':'-', delta);
		}
	}
	r_strbuf_free (sb);
}

static char *patch(RAsmPluginSession *aps, RAnalOp *aop, const char *op) {
	const ut8 *b = aop->bytes;
	int i, size = aop->size;
	char *hcmd = NULL;
	const char *cmd = NULL;
	if (!strcmp (op, "nop")) {
		if (size * 2 + 1 < size) {
			R_LOG_ERROR ("Cant fit a nop in here");
			return false;
		}
		hcmd = malloc ((size * 2) + 5);
		if (!hcmd) {
			return false;
		}
		strcpy (hcmd, "wx ");
		for (i = 0; i < size; i++) {
			memcpy (hcmd + 3 + (i * 2), "90", 2);
		}
		cmd = hcmd;
		hcmd[3 + (size * 2)] = '\0';
	} else if (!strcmp (op, "trap")) {
		cmd = "wx cc";
	} else if (!strcmp (op, "jz") || !strcmp (op, "je")) {
		if (b[0] == 0x75) {
			cmd = "wx 74";
		} else {
			R_LOG_ERROR ("Current opcode is not conditional");
		}
	} else if (!strcmp (op, "jinf")) {
		cmd = "wx ebfe";
	} else if (!strcmp (op, "jnz") || !strcmp (op, "jne")) {
		if (b[0] == 0x74) {
			cmd = "wx 75";
		} else {
			R_LOG_ERROR ("Current opcode is not conditional");
		}
	} else if (!strcmp (op, "nocj")) {
		if (*b == 0xf) {
			cmd = "wx 90e9";
		} else if (b[0] >= 0x70 && b[0] <= 0x7f) {
			cmd = "wx eb";
		} else {
			R_LOG_ERROR ("Current opcode is not conditional");
		}
	} else if (!strcmp (op, "recj")) {
		int is_near = (*b == 0xf);
		if (b[0] < 0x80 && b[0] >= 0x70) { // short jmps: jo, jno, jb, jae, je, jne, jbe, ja, js, jns
			cmd = hcmd = r_str_newf ("wx %x", (b[0]%2)? b[0] - 1: b[0] + 1);
		} else if (is_near && b[1] < 0x90 && b[1] >= 0x80) { // near jmps: jo, jno, jb, jae, je, jne, jbe, ja, js, jns
			cmd = hcmd = r_str_newf ("wx 0f%x", (b[1]%2)? b[1] - 1: b[1] + 1);
		} else {
			R_LOG_ERROR ("Invalid conditional jump opcode");
		}
	} else if (!strcmp (op, "ret1")) {
		cmd = "wx c20100";
	} else if (!strcmp (op, "ret0")) {
		cmd = "wx c20000";
	} else if (!strcmp (op, "retn")) {
		cmd = "wx c2ffff";
	} else {
		R_LOG_ERROR ("Invalid operation '%s'", op);
	}
	if (cmd) {
		if (hcmd) {
			return hcmd;
		}
		return strdup (cmd);
	}
	free (hcmd);
	return NULL;
}

static char *subvar(RAsmPluginSession *aps, RAnalFunction *f, ut64 addr, int oplen, const char *data) {
	RAsm *a = aps->rasm;
	RParse *p = a->parse;
	RAnal *anal = a->analb.anal;
	RListIter *iter;
	char oldstr[64], newstr[64];
	char *tstr = strdup (data);
	if (!tstr) {
		return NULL;
	}

	bool att = strchr (data, '%');

	if (p->subrel) {
		if (att) {
			char *rip = (char *) r_str_casestr (tstr, "(%rip)");
			if (rip) {
				*rip = 0;
				char *pre = tstr;
				char *pos = rip + 6;
				char *word = rip;
				while (word > tstr && *word != ' ') {
					word--;
				}

				if (word > tstr) {
					*word++ = 0;
					*rip = 0;
					st64 n = r_num_math (NULL, word);
					ut64 repl_num = oplen + addr + n;
					char *tstr_new = r_str_newf ("%s 0x%08"PFMT64x"%s", pre, repl_num, pos);
					*rip = '(';
					free (tstr);
					tstr = tstr_new;
				}
			}
		} else {
			char *rip = (char *) r_str_casestr (tstr, "[rip");
			if (rip) {
				char *ripend = strchr (rip + 3, ']');
				const char *plus = strchr (rip, '+');
				const char *neg = strchr (rip, '-');
				char *tstr_new;
				ut64 repl_num = oplen + addr;

				if (!ripend) {
					ripend = "]";
				}
				if (plus) {
					repl_num += r_num_get (NULL, plus + 1);
				}
				if (neg) {
					repl_num -= r_num_get (NULL, neg + 1);
				}

				rip[1] = '\0';
				tstr_new = r_str_newf ("%s0x%08"PFMT64x"%s", tstr, repl_num, ripend);
				free (tstr);
				tstr = tstr_new;
			}
		}
	}

	if (f && p->varlist) {
		RList *bpargs = p->varlist (f, 'b');
		RList *spargs = p->varlist (f, 's');
		/* Iterate over stack pointer arguments/variables */
		bool ucase = *tstr >= 'A' && *tstr <= 'Z';
		if (ucase && tstr[1]) {
			ucase = tstr[1] >= 'A' && tstr[1] <= 'Z';
		}
		char *ireg = p->get_op_ireg? p->get_op_ireg (p->user, addr): NULL;
		RList *groups[] = { spargs, bpargs };
		int kind;
		for (kind = 0; kind < R_ARRAY_SIZE (groups); kind++) {
			RAnalVarField *var;
			r_list_foreach (groups[kind], iter, var) {
				char sign = '+';
				st64 delta = p->get_ptr_at
					? p->get_ptr_at (f, var->delta, addr)
					: ST64_MAX;
				if (delta == ST64_MAX && var->field) {
					delta = var->delta + (kind? f->bp_off: f->maxstack);
				} else if (delta == ST64_MAX) {
					R_FREE (ireg);
					continue;
				}
				if (delta < 0) {
					sign = '-';
					delta = -delta;
				}
				const char *reg = p->get_reg_at? p->get_reg_at (f, var->delta, addr): NULL;
				if (!reg) {
					reg = anal->reg->alias[kind? R_REG_ALIAS_BP: R_REG_ALIAS_SP];
				}
				mk_reg_str (reg, delta, sign == '+', att, ireg, oldstr, sizeof (oldstr));
				if (ucase) {
					r_str_case (oldstr, true);
				}
				parse_localvar (a, newstr, sizeof (newstr), var->name, reg, sign, ireg, att);
				char *ptr = strstr (tstr, oldstr);
				if (ptr && (!att || (ptr > tstr && ptr[-1] == ' '))) {
					if (delta == 0) {
						char *end = ptr + strlen (oldstr);
						if (*end != ']' && *end != '\0') {
							continue;
						}
					}
					tstr = r_str_replace (tstr, oldstr, newstr, 1);
					break;
				} else {
					r_str_case (oldstr, false);
					ptr = strstr (tstr, oldstr);
					if (ptr && (!att || (ptr > tstr && ptr[-1] == ' '))) {
						tstr = r_str_replace (tstr, oldstr, newstr, 1);
						break;
					}
				}
				// BP operands can also omit spaces.
				if (!kind) {
					continue;
				}
				snprintf (oldstr, sizeof (oldstr) - 1, "[%s%c0x%x]", reg, sign, (int)delta);
				if (strstr (tstr, oldstr)) {
					r_strf_var (replacement, sizeof (newstr) + 2, "[%s]", newstr);
					tstr = r_str_replace (tstr, oldstr, replacement, 1);
					break;
				}
			}
		}
		R_FREE (ireg);
		r_list_free (spargs);
		r_list_free (bpargs);
	}

	return tstr;
}

static void fini(RAsmPluginSession *aps) {
	RParse *p = aps->rasm->parse;
	R_FREE (p->retleave_asm);
}

RAsmPlugin r_asm_plugin_x86 = {
	.meta = {
		.name = "x86",
		.desc = "X86 pseudo syntax",
		.author = "pancake",
		.license = "LGPL-3.0-only",
	},
	.parse = parse,
	.subvar = subvar,
	.patch = patch,
	.fini = fini,
};

#ifndef R2_PLUGIN_INCORE
R_API RLibStruct radare_plugin = {
	.type = R_LIB_TYPE_ASM,
	.data = &r_asm_plugin_x86,
	.version = R2_VERSION
};
#endif