compiler.c

UNIX、linux密码的破密程序源代码实现

			if (c_block('}', locals)) break; else continue;
		} else

		if (!strcmp(token, "void") || !strcmp(token, "int")) {
			if (c_define(term, &locals, vars)) break;
		} else

		if (!strcmp(token, "if") || !strcmp(token, "while")) {
			if (c_cond(term, locals, token)) break;
		} else

		if (!strcmp(token, "else"))
			return c_errno = C_ERROR_NOTINIF;
		else

		if (!strcmp(token, "continue")) {
			if (c_continue()) break;
		} else

		if (!strcmp(token, "break")) {
			if (c_break()) break;
		} else

		if (!strcmp(token, "return")) {
			if (c_return(term)) break;
		} else

		if (*token != ';')
			if (c_expr(term, locals, token)) break;

		if (c_errno) break;
	}

	c_free_ident(locals, vars);

	if (c_errno && c_EOF) c_errno = C_ERROR_EOF;

	return c_errno;
}

#ifdef __GNUC__
static void c_direct(union c_insn *addr);
#endif

int c_compile(int (*ext_getchar)(void), void (*ext_rewind)(void),
	struct c_ident *externs)
{
#ifdef __GNUC__
	c_direct(NULL);
#endif

	c_ext_getchar = ext_getchar;
	c_ext_rewind = ext_rewind;

	c_code_start = NULL;
	c_data_start = NULL;

	for (c_pass = 0; c_pass < 2; c_pass++) {
		c_init();
		c_block(0, externs);

		if (!c_pass) {
			c_free_ident(c_funcs, NULL);
			c_free_fixup(c_break_fixups, NULL);
		}

		if (c_errno || c_pass) break;

		c_code_start = mem_alloc((size_t)c_code_ptr);
		c_data_start = mem_alloc((size_t)c_data_ptr);
	}

	return c_errno;
}

struct c_ident *c_lookup(char *name)
{
	return c_find_ident(c_funcs, NULL, name);
}

void c_execute(struct c_ident *fn)
{
#ifndef __GNUC__
	register void (*op)(void);
#endif

	if (!fn) return;

#ifdef __GNUC__
	c_direct(fn->addr);
#else
	c_stack[0].pc = NULL;
	c_sp = &c_stack[2];

	c_pc = fn->addr;
	do {
		op = (c_pc++)->op;
		op();
	} while (c_pc);
#endif
}

#ifdef __GNUC__

static void c_direct(union c_insn *addr)
{
	union c_insn *pc = addr;
	union c_insn *sp = c_stack;
	c_int imm = 0;

	static void *ops[] = {
		&&op_index,
		&&op_assign,
		&&op_add_a,
		&&op_sub_a,
		&&op_mul_a,
		&&op_div_a,
		&&op_mod_a,
		&&op_or_a,
		&&op_xor_a,
		&&op_and_a,
		&&op_shl_a,
		&&op_shr_a,
		&&op_or_i,
		&&op_and_b,
		&&op_not_b,
		&&op_eq,
		&&op_sub,
		&&op_gt,
		&&op_lt,
		&&op_ge,
		&&op_le,
		&&op_or_i,
		&&op_xor_i,
		&&op_and_i,
		&&op_shl,
		&&op_shr,
		&&op_add,
		&&op_sub,
		&&op_mul,
		&&op_div,
		&&op_mod,
		&&op_not_i,
		&&op_neg,
		&&op_inc_l,
		&&op_dec_l,
		&&op_inc_r,
		&&op_dec_r,
	};

	if (!addr) {
		int op = 0;

		c_op_return = &&op_return;
		c_op_bz = &&op_bz;
		c_op_ba = &&op_ba;
		c_op_push_imm = &&op_push_imm;
		c_op_push_mem = &&op_push_mem;
		c_op_pop = &&op_pop;

		c_op_push_imm_imm = &&op_push_imm_imm;
		c_op_push_imm_mem = &&op_push_imm_mem;
		c_op_push_mem_imm = &&op_push_mem_imm;
		c_op_push_mem_mem = &&op_push_mem_mem;

		do {
			c_ops[op].op = ops[op];
		} while (c_ops[++op].prec);

		return;
	}

	goto *(pc++)->op;

op_return:
	return;

op_bz:
	if (imm) {
		pc += 2;
		sp -= 2;
		goto *(pc - 1)->op;
	}
	sp -= 2;

op_ba:
	pc = pc->pc;
	goto *(pc++)->op;

op_push_imm:
	(sp - 2)->imm = imm;
	imm = pc->imm;
	pc += 2;
	sp += 2;
	goto *(pc - 1)->op;

op_push_mem:
	(sp - 2)->imm = imm;
	imm = *((sp + 1)->mem = pc->mem);
	pc += 2;
	sp += 2;
	goto *(pc - 1)->op;

op_pop:
	sp -= 2;
	goto *(pc++)->op;

op_push_imm_imm:
	(sp - 2)->imm = imm;
	sp->imm = pc->imm;
	imm = (pc + 1)->imm;
	pc += 3;
	sp += 4;
	goto *(pc - 1)->op;

op_push_imm_mem:
	(sp - 2)->imm = imm;
	sp->imm = pc->imm;
	imm = *((sp + 3)->mem = (pc + 1)->mem);
	pc += 3;
	sp += 4;
	goto *(pc - 1)->op;

op_push_mem_imm:
	(sp - 2)->imm = imm;
	sp->imm = *((sp + 1)->mem = pc->mem);
	imm = (pc + 1)->imm;
	pc += 3;
	sp += 4;
	goto *(pc - 1)->op;

op_push_mem_mem:
	(sp - 2)->imm = imm;
	sp->imm = *((sp + 1)->mem = pc->mem);
	imm = *((sp + 3)->mem = (pc + 1)->mem);
	pc += 3;
	sp += 4;
	goto *(pc - 1)->op;

op_index:
	imm = *((sp - 3)->mem += imm);
	sp -= 2;
	goto *(pc++)->op;

op_assign:
	*(sp - 3)->mem = imm;
	sp -= 2;
	goto *(pc++)->op;

op_add_a:
	imm = *(sp - 3)->mem += imm;
	sp -= 2;
	goto *(pc++)->op;

op_sub_a:
	imm = *(sp - 3)->mem -= imm;
	sp -= 2;
	goto *(pc++)->op;

op_mul_a:
	imm = *(sp - 3)->mem *= imm;
	sp -= 2;
	goto *(pc++)->op;

op_div_a:
	imm = *(sp - 3)->mem /= imm;
	sp -= 2;
	goto *(pc++)->op;

op_mod_a:
	imm = *(sp - 3)->mem %= imm;
	sp -= 2;
	goto *(pc++)->op;

op_or_a:
	imm = *(sp - 3)->mem |= imm;
	sp -= 2;
	goto *(pc++)->op;

op_xor_a:
	imm = *(sp - 3)->mem ^= imm;
	sp -= 2;
	goto *(pc++)->op;

op_and_a:
	imm = *(sp - 3)->mem &= imm;
	sp -= 2;
	goto *(pc++)->op;

op_shl_a:
	imm = *(sp - 3)->mem <<= imm;
	sp -= 2;
	goto *(pc++)->op;

op_shr_a:
	imm = *(sp - 3)->mem >>= imm;
	sp -= 2;
	goto *(pc++)->op;

op_or_i:
	imm |= (sp - 4)->imm;
	sp -= 2;
	goto *(pc++)->op;

op_and_b:
	imm = (sp - 4)->imm && imm;
	sp -= 2;
	goto *(pc++)->op;

op_not_b:
	imm = !imm;
	goto *(pc++)->op;

op_eq:
	imm = (sp - 4)->imm == imm;
	sp -= 2;
	goto *(pc++)->op;

op_gt:
	imm = (sp - 4)->imm > imm;
	sp -= 2;
	goto *(pc++)->op;

op_lt:
	imm = (sp - 4)->imm < imm;
	sp -= 2;
	goto *(pc++)->op;

op_ge:
	imm = (sp - 4)->imm >= imm;
	sp -= 2;
	goto *(pc++)->op;

op_le:
	imm = (sp - 4)->imm <= imm;
	sp -= 2;
	goto *(pc++)->op;

op_xor_i:
	imm ^= (sp - 4)->imm;
	sp -= 2;
	goto *(pc++)->op;

op_and_i:
	imm &= (sp - 4)->imm;
	sp -= 2;
	goto *(pc++)->op;

op_shl:
	imm = (sp - 4)->imm << imm;
	sp -= 2;
	goto *(pc++)->op;

op_shr:
	imm = (sp - 4)->imm >> imm;
	sp -= 2;
	goto *(pc++)->op;

op_add:
	imm += (sp - 4)->imm;
	sp -= 2;
	goto *(pc++)->op;

op_sub:
	imm = (sp - 4)->imm - imm;
	sp -= 2;
	goto *(pc++)->op;

op_mul:
	imm *= (sp - 4)->imm;
	sp -= 2;
	goto *(pc++)->op;

op_div:
	imm = (sp - 4)->imm / imm;
	sp -= 2;
	goto *(pc++)->op;

op_mod:
	imm = (sp - 4)->imm % imm;
	sp -= 2;
	goto *(pc++)->op;

op_not_i:
	imm = ~imm;
	goto *(pc++)->op;

op_neg:
	imm = -imm;
	goto *(pc++)->op;

op_inc_l:
	*(sp - 1)->mem = ++imm;
	goto *(pc++)->op;

op_dec_l:
	*(sp - 1)->mem = --imm;
	goto *(pc++)->op;

op_inc_r:
	*(sp - 1)->mem = imm + 1;
	goto *(pc++)->op;

op_dec_r:
	*(sp - 1)->mem = imm - 1;
	goto *(pc++)->op;
}

#endif

static void c_f_op_return(void)
{
	c_pc = (c_sp -= 2)->pc;
}

static void c_f_op_bz(void)
{
	if ((c_sp -= 2)->imm)
		c_pc++;
	else
		c_pc = c_pc->pc;
}

static void c_f_op_ba(void)
{
	c_pc = c_pc->pc;
}

static void c_f_op_push_imm(void)
{
	c_sp->imm = (c_pc++)->imm;
	c_sp += 2;
}

static void c_f_op_push_mem(void)
{
	(c_sp++)->imm = *c_pc->mem;
	(c_sp++)->mem = (c_pc++)->mem;
}

static void c_f_op_pop(void)
{
	c_sp -= 2;
}

static void c_f_op_push_imm_imm(void)
{
	c_sp->imm = (c_pc++)->imm;
	(c_sp + 2)->imm = (c_pc++)->imm;
	c_sp += 4;
}

static void c_f_op_push_imm_mem(void)
{
	c_sp->imm = (c_pc++)->imm;
	(c_sp + 2)->imm = *c_pc->mem;
	(c_sp + 3)->mem = (c_pc++)->mem;
	c_sp += 4;
}

static void c_f_op_push_mem_imm(void)
{
	c_sp->imm = *c_pc->mem;
	(c_sp + 1)->mem = (c_pc++)->mem;
	(c_sp + 2)->imm = (c_pc++)->imm;
	c_sp += 4;
}

static void c_f_op_push_mem_mem(void)
{
	c_sp->imm = *c_pc->mem;
	(c_sp + 1)->mem = (c_pc++)->mem;
	(c_sp + 2)->imm = *c_pc->mem;
	(c_sp + 3)->mem = (c_pc++)->mem;
	c_sp += 4;
}

static void c_op_index(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *((c_sp - 1)->mem += c_sp->imm);
}

static void c_op_assign(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem = c_sp->imm;
}

static void c_op_add_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem += c_sp->imm;
}

static void c_op_sub_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem -= c_sp->imm;
}

static void c_op_mul_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem *= c_sp->imm;
}

static void c_op_div_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem /= c_sp->imm;
}

static void c_op_mod_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem %= c_sp->imm;
}

static void c_op_or_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem |= c_sp->imm;
}

static void c_op_xor_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem ^= c_sp->imm;
}

static void c_op_and_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem &= c_sp->imm;
}

static void c_op_shl_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem <<= c_sp->imm;
}

static void c_op_shr_a(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = *(c_sp - 1)->mem >>= c_sp->imm;
}

static void c_op_or_i(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm |= c_sp->imm;
}

static void c_op_and_b(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm && c_sp->imm;
}

static void c_op_not_b(void)
{
	(c_sp - 2)->imm = !(c_sp - 2)->imm;
}

static void c_op_eq(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm == c_sp->imm;
}

static void c_op_gt(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm > c_sp->imm;
}

static void c_op_lt(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm < c_sp->imm;
}

static void c_op_ge(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm >= c_sp->imm;
}

static void c_op_le(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm = (c_sp - 2)->imm <= c_sp->imm;
}

static void c_op_xor_i(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm ^= c_sp->imm;
}

static void c_op_and_i(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm &= c_sp->imm;
}

static void c_op_shl(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm <<= c_sp->imm;
}

static void c_op_shr(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm >>= c_sp->imm;
}

static void c_op_add(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm += c_sp->imm;
}

static void c_op_sub(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm -= c_sp->imm;
}

static void c_op_mul(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm *= c_sp->imm;
}

static void c_op_div(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm /= c_sp->imm;
}

static void c_op_mod(void)
{
	c_sp -= 2;
	(c_sp - 2)->imm %= c_sp->imm;
}

static void c_op_not_i(void)
{
	(c_sp - 2)->imm = ~(c_sp - 2)->imm;
}

static void c_op_neg(void)
{
	(c_sp - 2)->imm = -(c_sp - 2)->imm;
}

static void c_op_inc_l(void)
{
	*(c_sp - 1)->mem = ++(c_sp - 2)->imm;
}

static void c_op_dec_l(void)
{
	*(c_sp - 1)->mem = --(c_sp - 2)->imm;
}

static void c_op_inc_r(void)
{
	*(c_sp - 1)->mem = (c_sp - 2)->imm + 1;
}

static void c_op_dec_r(void)
{
	*(c_sp - 1)->mem = (c_sp - 2)->imm - 1;
}

static void (*c_op_return)(void) = c_f_op_return;
static void (*c_op_bz)(void) = c_f_op_bz;
static void (*c_op_ba)(void) = c_f_op_ba;
static void (*c_op_push_imm)(void) = c_f_op_push_imm;
static void (*c_op_push_mem)(void) = c_f_op_push_mem;
static void (*c_op_pop)(void) = c_f_op_pop;

static void (*c_op_push_imm_imm)(void) = c_f_op_push_imm_imm;
static void (*c_op_push_imm_mem)(void) = c_f_op_push_imm_mem;
static void (*c_op_push_mem_imm)(void) = c_f_op_push_mem_imm;
static void (*c_op_push_mem_mem)(void) = c_f_op_push_mem_mem;

static struct c_op c_ops[] = {
	{1, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "[", c_op_index},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "=", c_op_assign},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "+=", c_op_add_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "-=", c_op_sub_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "*=", c_op_mul_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "/=", c_op_div_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "%=", c_op_mod_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "|=", c_op_or_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "^=", c_op_xor_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "&=", c_op_and_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, "<<=", c_op_shl_a},
	{2, C_RIGHT_TO_LEFT, C_CLASS_BINARY, ">>=", c_op_shr_a},
	{3, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "||", c_op_or_i},
	{4, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "&&", c_op_and_b},
	{5, C_RIGHT_TO_LEFT, C_CLASS_LEFT, "!", c_op_not_b},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "==", c_op_eq},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "!=", c_op_sub},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, ">", c_op_gt},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "<", c_op_lt},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, ">=", c_op_ge},
	{6, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "<=", c_op_le},
	{7, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "|", c_op_or_i},
	{7, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "^", c_op_xor_i},
	{8, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "&", c_op_and_i},
	{9, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "<<", c_op_shl},
	{9, C_LEFT_TO_RIGHT, C_CLASS_BINARY, ">>", c_op_shr},
	{10, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "+", c_op_add},
	{10, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "-", c_op_sub},
	{11, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "*", c_op_mul},
	{11, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "/", c_op_div},
	{11, C_LEFT_TO_RIGHT, C_CLASS_BINARY, "%", c_op_mod},
	{12, C_RIGHT_TO_LEFT, C_CLASS_LEFT, "~", c_op_not_i},
	{12, C_RIGHT_TO_LEFT, C_CLASS_LEFT, "-", c_op_neg},
	{12, C_LEFT_TO_RIGHT, C_CLASS_LEFT, "++", c_op_inc_l},
	{12, C_LEFT_TO_RIGHT, C_CLASS_LEFT, "--", c_op_dec_l},
	{12, C_LEFT_TO_RIGHT, C_CLASS_RIGHT, "++", c_op_inc_r},
	{12, C_LEFT_TO_RIGHT, C_CLASS_RIGHT, "--", c_op_dec_r},
	{0}
};