#include <stdint.h>
#include <sys/select.h>
#include <getopt.h>
+#include <termios.h>
#define VERSION 1
void
print_usage(char ** argv)
{
- printf( "Whitespace Interpreter v%d (www.subgeniuskitty.com)\n"
+ printf( "VVhitespace Interpreter v%d (www.subgeniuskitty.com)\n"
"Usage: %s -i <file>\n"
" -h Help (prints this message)\n"
- " -i <file> Specify a Whitespace source file to interpret.\n"
+ " -i <file> Specify a VVhitespace source file to interpret.\n"
, VERSION, argv[0]
);
}
return 1;
}
+void
+set_terminal_mode(void)
+{
+ struct termios options;
+ tcgetattr(STDIN_FILENO, &options);
+ /* Create a cbreak-like environment through the following options. */
+ options.c_lflag &= ~ECHO; /* Disable echoing of input characters. */
+ options.c_lflag &= ~ICANON; /* Disable cooked/line-oriented mode. */
+ options.c_cc[VMIN] = 1;
+ options.c_cc[VTIME] = 0;
+ tcsetattr(STDIN_FILENO, TCSANOW, &options);
+}
+
+void
+unset_terminal_mode(void)
+{
+ struct termios options;
+ tcgetattr(STDIN_FILENO, &options);
+ /* Undo the changes made in set_terminal_mode(). */
+ options.c_lflag |= ECHO; /* Enable echoing of input characters. */
+ options.c_lflag |= ICANON; /* Enable cooked/line-oriented mode. */
+ options.c_cc[VMIN] = 1; /* Default value from /usr/src/sys/sys/ttydefaults.h */
+ options.c_cc[VTIME] = 0; /* Default value from /usr/src/sys/sys/ttydefaults.h */
+ tcsetattr(STDIN_FILENO, TCSANOW, &options);
+}
+
void
ws_die(size_t * pc, char * msg)
{
- printf("\n");
printf("SIM_ERROR @ PC %lu: %s\n", *pc, msg);
fflush(stdout);
+ unset_terminal_mode();
exit(EXIT_FAILURE);
}
return code[(*pc)++];
}
+/*
+ * In addition to returning the parsed label, this function advances the PC to
+ * the next instruction.
+ */
uint16_t
parse_label(uint8_t * code, size_t * pc)
{
label = label << 1;
if (c == ' ') label++;
}
+ // TODO: Where should I handle attempts to access an unitialized label?
+ // For now, leave it undefined in a nasal demon sense.
return label;
}
+void
+populate_labels(uint32_t * labels, uint8_t * code, size_t code_size)
+{
+ size_t cp = 0;
+ while (cp <= code_size) {
+ if (code[cp] == '\v') {
+ uint16_t temp_label = parse_label(code, &cp);
+ labels[temp_label] = cp;
+ }
+ cp++;
+ }
+}
+
void
process_imp_stack(uint8_t * code, size_t * pc, int32_t ** sp)
{
switch (next_code_byte(code,pc)) {
case ' ' : sign = 1; break;
case '\t': sign = -1; break;
- case '\n': ws_die(pc, "expected sign"); break;
+ default : ws_die(pc, "expected sign"); break;
}
/* Now, construct the number and push to TOS. */
/* I'm assuming the numbers are read MSb first. */
int32_t temp, number = 0;
while ((temp = next_code_byte(code,pc)) != '\n') {
+ if (temp == '\v') ws_die(pc, "non-binary digit in number");
number <<= 1;
if (temp == '\t') number++;
}
case '\n':
stack_pop(sp);
break;
+ default:
+ ws_die(pc, "malformed stack IMP");
+ break;
}
}
break;
- case '\t': ws_die(pc, "malformed stack IMP"); break;
+ default: ws_die(pc, "malformed stack IMP"); break;
}
}
/* Multiplication */
stack_push(sp, stack_pop(sp)*stack_pop(sp));
break;
+ default:
+ ws_die(pc, "malformed arithmetic IMP");
+ break;
}
}
break;
temp = stack_pop(sp);
stack_push(sp, stack_pop(sp)%temp);
break;
- case '\n': ws_die(pc, "malformed arithmetic IMP"); break;
+ default: ws_die(pc, "malformed arithmetic IMP"); break;
}
}
break;
- case '\n': ws_die(pc, "malformed arithmetic IMP"); break;
+ default: ws_die(pc, "malformed arithmetic IMP"); break;
}
}
switch (next_code_byte(code,pc)) {
case '\n':
/* Technically another LF is required but we ignore it. */
- printf("\n");
fflush(stdout);
+ unset_terminal_mode();
exit(EXIT_SUCCESS);
case ' ':
{
switch (next_code_byte(code,pc)) {
case ' ':
/* Mark a location in the program. */
- labels[parse_label(code, pc)] = *pc;
+ if (next_code_byte(code,pc) != '\v') ws_die(pc,"expected vtab, "
+ "perhaps a whitespace program, rather than vvhitespace?");
+ /* Jump to next instruction since labels were parsed during startup. */
+ parse_label(code, pc);
break;
case '\t':
/* Call a subroutine. */
- *((*rsp)++) = *pc;
- *pc = labels[parse_label(code, pc)];
+ {
+ size_t temp_pc = labels[parse_label(code, pc)];
+ *((*rsp)++) = *pc;
+ *pc = temp_pc;
+ }
break;
case '\n':
/* Jump unconditionally to a label. */
*pc = labels[parse_label(code, pc)];
break;
+ default:
+ ws_die(pc, "malformed flow control IMP");
+ break;
}
}
break;
switch (next_code_byte(code,pc)) {
case ' ':
/* Jump to a label if TOS == 0 */
+ /* TODO: Does WS pop or peek the TOS? */
if (stack_peek(sp,0) == 0) *pc = labels[parse_label(code, pc)];
break;
case '\t':
/* Jump to a label if TOS < 0. */
+ /* TODO: Does WS pop or peek the TOS? */
if (stack_peek(sp,0) < 0) *pc = labels[parse_label(code, pc)];
break;
case '\n':
/* Return from subroutine. */
*pc = *(--(*rsp));
break;
+ default:
+ ws_die(pc, "malformed flow control IMP");
+ break;
}
}
break;
+ default:
+ ws_die(pc, "malformed flow control IMP");
+ break;
}
}
process_imp_heap(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp)
{
switch (next_code_byte(code,pc)) {
- case ' ' : /* Store to heap */ *(*hp + *((*sp)-1)) = **sp; *sp -= 2; break;
- case '\t': /* Retrieve from heap */ **sp = *(*hp + **sp); break;
- case '\n': ws_die(pc, "malformed heap IMP"); break;
+ case ' ' :
+ /* Store to heap */
+ {
+ int32_t value = stack_pop(sp);
+ int32_t addr = stack_pop(sp);
+ *(*hp + addr) = value;
+ }
+ break;
+ case '\t':
+ /* Retrieve from heap */
+ stack_push(sp, *(*hp + stack_pop(sp)));
+ break;
+ default:
+ ws_die(pc, "malformed heap IMP");
+ break;
}
}
/* Output */
{
switch (next_code_byte(code,pc)) {
- case ' ' : /* Output character from TOS */ printf("%c", stack_pop(sp)); break;
- case '\t': /* Output number from TOS */ printf("%d", stack_pop(sp)); break;
- case '\n': ws_die(pc, "malformed output IMP"); break;
+ case ' ' : /* Output char from TOS */ printf("%c", stack_pop(sp)); break;
+ case '\t': /* Output digit from TOS */ printf("%c", stack_pop(sp)+'0'); break;
+ default : ws_die(pc, "malformed output IMP"); break;
}
fflush(stdout);
}
char c = getchar();
switch (next_code_byte(code,pc)) {
case '\t': /* Input digit */ c -= '0'; /* fallthrough */
- case ' ' : /* Input character */ *(*hp + *((*sp)--)) = c; break;
- case '\n': ws_die(pc, "malformed input IMP"); break;
+ case ' ' : /* Input character */ *(*hp + *(--(*sp))) = c; break;
+ default : ws_die(pc, "malformed input IMP"); break;
}
}
break;
- case '\n': ws_die(pc, "malformed i/o IMP"); break;
+ default: ws_die(pc, "malformed i/o IMP"); break;
}
}
-/* TODO: Continue cleanup here */
-
int
main(int argc, char ** argv)
{
}
}
if (input == NULL) {
- fprintf(stderr, "ERROR: Must specify a Whitespace source file with -f flag.\n");
+ fprintf(stderr, "ERROR: Must specify a VVhitespace source file with -f flag.\n");
print_usage(argv);
exit(EXIT_FAILURE);
}
/*
- * Read just the Whitespace source code into memory.
+ * Read just the VVhitespace source code into memory.
* We will use the array indices as addresses for the virtual PC when jumping to labels.
*/
size_t ws_code_size = 0;
uint8_t temp_byte;
while (fread(&temp_byte, 1, 1, input)) {
- if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n') ws_code_size++;
+ if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') {
+ ws_code_size++;
+ }
}
rewind(input);
uint8_t * ws_code_space = malloc(ws_code_size);
ws_code_size = 0;
while (fread(&temp_byte, 1, 1, input)) {
- if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n') ws_code_space[ws_code_size++] = temp_byte;
+ if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') {
+ ws_code_space[ws_code_size++] = temp_byte;
+ }
}
fclose(input);
* Setup a stack and heap.
* Assume a 32-bit word size.
*/
+ // TODO: Make everything 64-bit.
int32_t * hp = malloc(HEAPSIZE*4);
int32_t * sp = malloc(STACKSIZE*4);
* Setup the return stack and the label array.
*/
uint32_t * rsp = malloc(RETURNSTACKSIZE*4);
- uint32_t labels[65536];
+ uint32_t labels[65536] = {0};
+ populate_labels(labels, ws_code_space, ws_code_size);
/*
* Main Loop
*/
-
+ set_terminal_mode();
size_t pc = 0; /* Virtual program counter. Operates in the ws_code_space[] address space. */
while (1) {
if (pc >= ws_code_size) {
- fprintf(stderr, "SIM_ERROR: PC Overrun\n Requested PC: %lu\n Max Address: %lu\n", pc, ws_code_size-1);
+ fprintf(stderr, "SIM_ERROR: PC Overrun\n Requested PC: %lu\n Max Address: %lu\n",
+ pc, ws_code_size-1);
exit(EXIT_FAILURE);
+ unset_terminal_mode();
}
/* Decode the IMPs */
}
}
break;
+ default: ws_die(&pc, "unexpected VTab"); break;
}
}
printf("Program executed.\n");
exit(EXIT_SUCCESS);
+ unset_terminal_mode();
}