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|
#include <platform.h>
#include <ducky.h>
#include "opcodes.h"
#define STACK_SZ 1024
#define CALLSTACK_SZ 64
#define MAX_VARS 65536
static imm_t callstack[CALLSTACK_SZ];
static unsigned callstack_pointer;
static imm_t stack[STACK_SZ];
static unsigned stack_pointer;
static jmp_buf exit_point;
struct var_t {
enum { TYPE_PLAIN, TYPE_SPECIAL } type;
union {
vartype val;
struct {
enum special_id special;
};
};
bool constant;
};
static struct var_t vars[MAX_VARS];
static int file_des;
static unsigned current_line, num_lines;
static off_t *line_offset;
static bool want_quit;
static int repeats_left;
static imm_t repeat_line;
static void vid_write(const char *str);
instr_t read_instr(void)
{
instr_t ret;
if(read(file_des, &ret, sizeof(ret)) != sizeof(ret))
want_quit = true;
return ret;
}
imm_t read_imm(void)
{
imm_t ret;
if(read(file_des, &ret, sizeof(ret)) != sizeof(ret))
want_quit = true;
return ret;
}
imm_t read_varid(void)
{
varid_t ret;
if(read(file_des, &ret, sizeof(ret)) != sizeof(ret))
want_quit = true;
return ret;
}
imm_t read_byte(void)
{
unsigned char ret;
if(read(file_des, &ret, sizeof(ret)) != sizeof(ret))
want_quit = true;
return ret;
}
static void vid_write(const char *str)
{
printf("%s", str);
}
static void __attribute__((format(printf,1,2))) vid_writef(const char *fmt, ...)
{
char fmtbuf[256];
va_list ap;
va_start(ap, fmt);
vsnprintf(fmtbuf, sizeof(fmtbuf), fmt, ap);
vid_write(fmtbuf);
va_end(ap);
}
static void __attribute__((format(printf,1,2))) warning(const char *fmt, ...)
{
char fmtbuf[256];
va_list ap;
va_start(ap, fmt);
vsnprintf(fmtbuf, sizeof(fmtbuf), fmt, ap);
vid_writef("Line %d: WARNING: %s\n", current_line, fmtbuf);
va_end(ap);
}
static void init_globals(void)
{
current_line = 0;
stack_pointer = 0;
callstack_pointer = 0;
want_quit = false;
repeats_left = 0;
repeat_line = 0;
}
static inline void push(imm_t n)
{
if(stack_pointer < STACK_SZ)
stack[stack_pointer++] = n;
else
ERROR("stack overflow");
}
static inline imm_t pop(void)
{
if(stack_pointer > 0)
return stack[--stack_pointer];
else
ERROR("stack underflow");
}
static inline vartype getvar(varid_t varid)
{
if(varid < ARRAYLEN(vars))
{
struct var_t *var = vars+varid;
if(var->type == TYPE_PLAIN)
return vars[varid].val;
else
return get_special(vars[varid].special);
}
}
static inline void setvar(varid_t varid, vartype val)
{
if(varid < ARRAYLEN(vars) && !vars[varid].constant)
vars[varid].val = val;
else
ERROR("cannot modify variable");
}
static inline void mkconst(varid_t varid)
{
if(varid < ARRAYLEN(vars))
vars[varid].constant = true;
}
static inline void jump(imm_t line)
{
if(1 <= line && line <= num_lines)
{
lseek(file_des, line_offset[line], SEEK_SET);
current_line = line;
}
else
ERROR("jump target out of bounds");
}
static void pushimm_handler(void)
{
push(read_imm());
}
static void pushvar_handler(void)
{
push(getvar(read_varid()));
}
static void pop_handler(void)
{
setvar(read_varid(), pop());
}
static void mkconst_handler(void)
{
mkconst(read_varid());
}
static void incvar_handler(void)
{
varid_t varid = read_varid();
if(varid < ARRAYLEN(vars))
++vars[varid].val;
}
static void decvar_handler(void)
{
varid_t varid = read_varid();
if(varid < ARRAYLEN(vars))
--vars[varid].val;
}
static void writestr_handler(void)
{
while(1)
{
char c = read_byte();
if(c)
vid_writef("%c", c);
else
break;
}
}
static void repeat_handler(void)
{
if(repeats_left > 0)
{
if(repeat_line + 1 != current_line)
ERROR("nested REPEAT");
--repeats_left;
if(repeats_left > 0)
{
jump(repeat_line);
}
}
else
{
repeat_line = pop();
repeats_left = pop() - 1;
jump(repeat_line);
}
}
static void jump_handler(void)
{
jump(pop());
}
static void subcall_handler(void)
{
if(callstack_pointer < CALLSTACK_SZ)
{
callstack[callstack_pointer++] = current_line + 1;
jump(pop());
}
else
ERROR("call stack overflow");
}
static void subret_handler(void)
{
if(callstack_pointer > 0)
{
jump(callstack[--callstack_pointer]);
}
else
ERROR("call stack underflow");
}
static void if_handler(void)
{
imm_t line = pop();
if(!pop())
jump(line);
}
static void delay_handler(void)
{
imm_t ms = pop();
struct timespec t;
t.tv_sec = ms / 1000;
t.tv_nsec = (ms % 1000) * 1000000;
nanosleep(&t, NULL);
}
static void logvar_handler(void)
{
vid_writef(VARFORMAT, pop());
}
static void quit_handler(void)
{
want_quit = true;
}
static void logascii_handler(void)
{
vid_writef("%c", pop());
}
static void neg_handler(void)
{
stack[stack_pointer - 1] = -stack[stack_pointer - 1];
}
static vartype eval_exp(vartype a1, vartype a2)
{
return a2<0 ? 0 : (a2==0?1:a1*eval_exp(a1, a2-1));
}
static void pow_handler(void)
{
imm_t pow = pop();
imm_t base = pop();
push(eval_exp(base, pow));
}
static void mul_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a*b);
}
static void div_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a/b);
}
static void mod_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a%b);
}
static void add_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a+b);
}
static void sub_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a-b);
}
static void eq_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a==b);
}
static void neq_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a!=b);
}
static void leq_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a<=b);
}
static void geq_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a>=b);
}
static void lt_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a<b);
}
static void gt_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a>b);
}
static void lognot_handler(void)
{
push(!pop());
}
static void logand_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a&&b);
}
static void logor_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a||b);
}
static void bitand_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a&b);
}
static void bitor_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a|b);
}
static void bitxor_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a^b);
}
static void bitcomp_handler(void)
{
push(~pop());
}
static void lsh_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a<<b);
}
static void rsh_handler(void)
{
imm_t b = pop();
imm_t a = pop();
push(a>>b);
}
static void sqrt_handler(void)
{
push(sqrt(pop()));
}
static void decl_const(void)
{
/* no checking, only the compiler can output this instruction */
varid_t varid = read_varid();
vars[varid].val = read_imm();
vars[varid].constant = true;
}
static void newline_handler(void)
{
vid_writef("\n");
}
static void input_handler(void)
{
vartype val;
scanf(VARFORMAT, &val);
setvar(read_varid(), val);
}
static void mkspecial_handler(void)
{
varid_t varid = read_varid();
vars[varid].constant = true;
vars[varid].type = TYPE_SPECIAL;
vars[varid].special = read_imm();
}
static void inc_line_pointer(void)
{
++current_line;
vars[0].val = current_line;
}
static void (*instr_tab[0x100])(void) = {
pushimm_handler, /* 0x0 */
pushvar_handler, /* 0x1 */
pop_handler, /* 0x2 */
mkconst_handler, /* 0x3 */
incvar_handler, /* 0x4 */
decvar_handler, /* 0x5 */
writestr_handler, /* 0x6 */
repeat_handler, /* 0x7 */
jump_handler, /* 0x8 */
subcall_handler, /* 0x9 */
subret_handler, /* 0xa */
if_handler, /* 0xb */
delay_handler, /* 0xc */
logvar_handler, /* 0xd */
quit_handler, /* 0xe */
logascii_handler, /* 0xf */
neg_handler, /* 0x10 */
pow_handler, /* 0x11 */
mul_handler, /* 0x12 */
div_handler, /* 0x13 */
mod_handler, /* 0x14 */
add_handler, /* 0x15 */
sub_handler, /* 0x16 */
eq_handler, /* 0x17 */
neq_handler, /* 0x18 */
leq_handler, /* 0x19 */
geq_handler, /* 0x1a */
lt_handler, /* 0x1b */
gt_handler, /* 0x1c */
lognot_handler, /* 0x1d */
logand_handler, /* 0x1e */
logor_handler, /* 0x1f */
bitand_handler, /* 0x20 */
bitor_handler, /* 0x21 */
bitxor_handler, /* 0x22 */
bitcomp_handler, /* 0x23 */
lsh_handler, /* 0x24 */
rsh_handler, /* 0x25 */
sqrt_handler, /* 0x26 */
decl_const, /* 0x27 */
NULL, /* 0x28 */
NULL, /* 0x29 */
NULL, /* 0x2a */
NULL, /* 0x2b */
NULL, /* 0x2c */
NULL, /* 0x2d */
newline_handler, /* 0x2e */
input_handler, /* 0x2f */
mkspecial_handler, /* 0x30 */
NULL, /* 0x31 */
NULL, /* 0x32 */
NULL, /* 0x33 */
NULL, /* 0x34 */
NULL, /* 0x35 */
NULL, /* 0x36 */
NULL, /* 0x37 */
NULL, /* 0x38 */
NULL, /* 0x39 */
NULL, /* 0x3a */
NULL, /* 0x3b */
NULL, /* 0x3c */
NULL, /* 0x3d */
NULL, /* 0x3e */
NULL, /* 0x3f */
NULL, /* 0x40 */
NULL, /* 0x41 */
NULL, /* 0x42 */
NULL, /* 0x43 */
NULL, /* 0x44 */
NULL, /* 0x45 */
NULL, /* 0x46 */
NULL, /* 0x47 */
NULL, /* 0x48 */
NULL, /* 0x49 */
NULL, /* 0x4a */
NULL, /* 0x4b */
NULL, /* 0x4c */
NULL, /* 0x4d */
NULL, /* 0x4e */
NULL, /* 0x4f */
NULL, /* 0x50 */
NULL, /* 0x51 */
NULL, /* 0x52 */
NULL, /* 0x53 */
NULL, /* 0x54 */
NULL, /* 0x55 */
NULL, /* 0x56 */
NULL, /* 0x57 */
NULL, /* 0x58 */
NULL, /* 0x59 */
NULL, /* 0x5a */
NULL, /* 0x5b */
NULL, /* 0x5c */
NULL, /* 0x5d */
NULL, /* 0x5e */
NULL, /* 0x5f */
NULL, /* 0x60 */
NULL, /* 0x61 */
NULL, /* 0x62 */
NULL, /* 0x63 */
NULL, /* 0x64 */
NULL, /* 0x65 */
NULL, /* 0x66 */
NULL, /* 0x67 */
NULL, /* 0x68 */
NULL, /* 0x69 */
NULL, /* 0x6a */
NULL, /* 0x6b */
NULL, /* 0x6c */
NULL, /* 0x6d */
NULL, /* 0x6e */
NULL, /* 0x6f */
NULL, /* 0x70 */
NULL, /* 0x71 */
NULL, /* 0x72 */
NULL, /* 0x73 */
NULL, /* 0x74 */
NULL, /* 0x75 */
NULL, /* 0x76 */
NULL, /* 0x77 */
NULL, /* 0x78 */
NULL, /* 0x79 */
NULL, /* 0x7a */
NULL, /* 0x7b */
NULL, /* 0x7c */
NULL, /* 0x7d */
NULL, /* 0x7e */
NULL, /* 0x7f */
NULL, /* 0x80 */
NULL, /* 0x81 */
NULL, /* 0x82 */
NULL, /* 0x83 */
NULL, /* 0x84 */
NULL, /* 0x85 */
NULL, /* 0x86 */
NULL, /* 0x87 */
NULL, /* 0x88 */
NULL, /* 0x89 */
NULL, /* 0x8a */
NULL, /* 0x8b */
NULL, /* 0x8c */
NULL, /* 0x8d */
NULL, /* 0x8e */
NULL, /* 0x8f */
NULL, /* 0x90 */
NULL, /* 0x91 */
NULL, /* 0x92 */
NULL, /* 0x93 */
NULL, /* 0x94 */
NULL, /* 0x95 */
NULL, /* 0x96 */
NULL, /* 0x97 */
NULL, /* 0x98 */
NULL, /* 0x99 */
NULL, /* 0x9a */
NULL, /* 0x9b */
NULL, /* 0x9c */
NULL, /* 0x9d */
NULL, /* 0x9e */
NULL, /* 0x9f */
NULL, /* 0xa0 */
NULL, /* 0xa1 */
NULL, /* 0xa2 */
NULL, /* 0xa3 */
NULL, /* 0xa4 */
NULL, /* 0xa5 */
NULL, /* 0xa6 */
NULL, /* 0xa7 */
NULL, /* 0xa8 */
NULL, /* 0xa9 */
NULL, /* 0xaa */
NULL, /* 0xab */
NULL, /* 0xac */
NULL, /* 0xad */
NULL, /* 0xae */
NULL, /* 0xaf */
NULL, /* 0xb0 */
NULL, /* 0xb1 */
NULL, /* 0xb2 */
NULL, /* 0xb3 */
NULL, /* 0xb4 */
NULL, /* 0xb5 */
NULL, /* 0xb6 */
NULL, /* 0xb7 */
NULL, /* 0xb8 */
NULL, /* 0xb9 */
NULL, /* 0xba */
NULL, /* 0xbb */
NULL, /* 0xbc */
NULL, /* 0xbd */
NULL, /* 0xbe */
NULL, /* 0xbf */
NULL, /* 0xc0 */
NULL, /* 0xc1 */
NULL, /* 0xc2 */
NULL, /* 0xc3 */
NULL, /* 0xc4 */
NULL, /* 0xc5 */
NULL, /* 0xc6 */
NULL, /* 0xc7 */
NULL, /* 0xc8 */
NULL, /* 0xc9 */
NULL, /* 0xca */
NULL, /* 0xcb */
NULL, /* 0xcc */
NULL, /* 0xcd */
NULL, /* 0xce */
NULL, /* 0xcf */
NULL, /* 0xd0 */
NULL, /* 0xd1 */
NULL, /* 0xd2 */
NULL, /* 0xd3 */
NULL, /* 0xd4 */
NULL, /* 0xd5 */
NULL, /* 0xd6 */
NULL, /* 0xd7 */
NULL, /* 0xd8 */
NULL, /* 0xd9 */
NULL, /* 0xda */
NULL, /* 0xdb */
NULL, /* 0xdc */
NULL, /* 0xdd */
NULL, /* 0xde */
NULL, /* 0xdf */
NULL, /* 0xe0 */
NULL, /* 0xe1 */
NULL, /* 0xe2 */
NULL, /* 0xe3 */
NULL, /* 0xe4 */
NULL, /* 0xe5 */
NULL, /* 0xe6 */
NULL, /* 0xe7 */
NULL, /* 0xe8 */
NULL, /* 0xe9 */
NULL, /* 0xea */
NULL, /* 0xeb */
NULL, /* 0xec */
NULL, /* 0xed */
NULL, /* 0xee */
NULL, /* 0xef */
NULL, /* 0xf0 */
NULL, /* 0xf1 */
NULL, /* 0xf2 */
NULL, /* 0xf3 */
NULL, /* 0xf4 */
NULL, /* 0xf5 */
NULL, /* 0xf6 */
NULL, /* 0xf7 */
NULL, /* 0xf8 */
NULL, /* 0xf9 */
NULL, /* 0xfa */
NULL, /* 0xfb */
NULL, /* 0xfc */
NULL, /* 0xfd */
NULL, /* 0xfe */
inc_line_pointer, /* 0xff */
};
int ducky_vm(int fd)
{
if(!setjmp(exit_point))
{
file_des = fd;
init_globals();
if(read_imm() != DUCKY_MAGIC)
ERROR("unknown format");
num_lines = read_imm();
line_offset = malloc(num_lines + 1);
for(unsigned int i = 1; i <= num_lines; ++i)
{
line_offset[i] = read_imm();
}
/* and... execute! */
while(!want_quit)
{
instr_t instr = read_instr();
if(want_quit)
break;
void (*handler)(void) = instr_tab[instr];
if(handler)
handler();
else
ERROR("invalid instruction");
}
return 0;
}
else
return 1;
}
|
