#include <stdint.h>
#include <sys/select.h>
#include <getopt.h>
+#include <termios.h>
#define VERSION 1
-#define STACKSIZE 1024
-#define HEAPSIZE 1024
-#define RETURNSTACKSIZE 1024
+#define HEAPSIZE 1024 /* Size of heap in words */
+#define DATASTACKSIZE 1024 /* Size of stack in words */
+#define RETURNSTACKSIZE 1024 /* Max subroutine call depth */
void
print_usage(char ** argv)
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("SIM_ERROR @ PC %lu: %s\n", *pc, msg);
fflush(stdout);
+ unset_terminal_mode();
exit(EXIT_FAILURE);
}
void
-stack_push(int32_t ** sp, int32_t word)
+stack_push(int64_t ** sp, int64_t word)
{
*((*sp)++) = word;
}
-int32_t
-stack_pop(int32_t ** sp)
+int64_t
+stack_pop(int64_t ** sp)
{
return *(--(*sp));
}
-int32_t
-stack_peek(int32_t ** sp, size_t offset)
+int64_t
+stack_peek(int64_t ** sp, size_t offset)
/* offset=0 peeks TOS, offset=1 peeks NOS, etc. */
{
return *((*sp)-offset-1);
uint8_t c;
while ((c = code[(*pc)++]) != '\n') {
label = label << 1;
- if (c == ' ') label++;
+ if (c == '\t') label++;
}
// TODO: Where should I handle attempts to access an unitialized label?
// For now, leave it undefined in a nasal demon sense.
}
void
-populate_labels(uint32_t * labels, uint8_t * code, size_t code_size)
+populate_labels(size_t * labels, uint8_t * code, size_t code_size)
{
size_t cp = 0;
while (cp <= code_size) {
- if (code[cp] == '\v') {
+ 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)
+process_imp_stack(uint8_t * code, size_t * pc, int64_t ** sp)
{
switch (next_code_byte(code,pc)) {
case ' ':
/* Push number onto TOS. */
{
/* First, pick off the sign */
- int32_t sign = 0;
+ int64_t sign = 0;
switch (next_code_byte(code,pc)) {
case ' ' : sign = 1; break;
case '\t': sign = -1; break;
/* Now, construct the number and push to TOS. */
/* I'm assuming the numbers are read MSb first. */
- int32_t temp, number = 0;
+ int64_t number = 0;
+ uint8_t temp;
while ((temp = next_code_byte(code,pc)) != '\n') {
if (temp == '\v') ws_die(pc, "non-binary digit in number");
number <<= 1;
/* Swap TOS and NOS. */
case '\t':
{
- int32_t t1 = stack_pop(sp);
- int32_t t2 = stack_pop(sp);
+ int64_t t1 = stack_pop(sp);
+ int64_t t2 = stack_pop(sp);
stack_push(sp, t1);
stack_push(sp, t2);
}
}
void
-process_imp_arithmetic(uint8_t * code, size_t * pc, int32_t ** sp)
+process_imp_arithmetic(uint8_t * code, size_t * pc, int64_t ** sp)
{
- int32_t temp;
+ int64_t temp;
switch (next_code_byte(code,pc)) {
case ' ':
{
}
void
-process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * labels,
- uint32_t ** rsp)
+process_imp_flowcontrol(uint8_t * code, size_t * pc, int64_t ** sp, size_t * labels,
+ size_t ** rsp)
{
+ size_t temp_pc;
switch (next_code_byte(code,pc)) {
case '\n':
/* Technically another LF is required but we ignore it. */
fflush(stdout);
+ unset_terminal_mode();
exit(EXIT_SUCCESS);
case ' ':
{
break;
case '\t':
/* Call a subroutine. */
- {
- size_t temp_pc = labels[parse_label(code, pc)];
- *((*rsp)++) = *pc;
- *pc = temp_pc;
- }
+ temp_pc = labels[parse_label(code, pc)];
+ *((*rsp)++) = *pc;
+ *pc = temp_pc;
break;
case '\n':
/* Jump unconditionally to a label. */
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)];
+ temp_pc = labels[parse_label(code, pc)];
+ if (stack_pop(sp) == 0) *pc = temp_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)];
+ temp_pc = labels[parse_label(code, pc)];
+ if (stack_pop(sp) < 0) *pc = temp_pc;
break;
case '\n':
/* Return from subroutine. */
}
void
-process_imp_heap(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp)
+process_imp_heap(uint8_t * code, size_t * pc, int64_t ** sp, int64_t ** hp)
{
switch (next_code_byte(code,pc)) {
case ' ' :
/* Store to heap */
{
- int32_t value = stack_pop(sp);
- int32_t addr = stack_pop(sp);
+ int64_t value = stack_pop(sp);
+ int64_t addr = stack_pop(sp);
*(*hp + addr) = value;
}
break;
}
void
-process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp)
+process_imp_io(uint8_t * code, size_t * pc, int64_t ** sp, int64_t ** hp)
{
switch (next_code_byte(code,pc)) {
case ' ':
/* Output */
{
switch (next_code_byte(code,pc)) {
- case ' ' : /* Output char from TOS */ printf("%c", stack_pop(sp)); break;
- case '\t': /* Output digit from TOS */ printf("%c", stack_pop(sp)+'0'); break;
+ case ' ' : /* Output char from TOS */ printf("%c", (uint8_t) stack_pop(sp)); break;
+ case '\t': /* Output digit from TOS */ printf("%c", (uint8_t) 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 ' ' : /* Input character */ *(*hp + *(--(*sp))) = c; break;
default : ws_die(pc, "malformed input IMP"); break;
}
}
}
/*
- * Read just the VVhitespace source code into memory.
+ * Read just the VVhitespace source code into memory, stripping comment characters.
* We will use the array indices as addresses for the virtual PC when jumping to labels.
*/
size_t ws_code_size = 0;
/*
* 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);
+ int64_t * hp = malloc(HEAPSIZE*sizeof(int64_t));
+ int64_t * sp = malloc(DATASTACKSIZE*sizeof(int64_t));
/*
* Setup the return stack and the label array.
*/
- uint32_t * rsp = malloc(RETURNSTACKSIZE*4);
- uint32_t labels[65536] = {0};
+ size_t * rsp = malloc(RETURNSTACKSIZE*sizeof(size_t));
+ size_t labels[65536] = {0}; /* 65536 = 2^16 => Holds all possible labels. */
+ /* Default value of zero indicates an uninitialized label. */
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);
exit(EXIT_FAILURE);
+ unset_terminal_mode();
}
-// TODO: Have the SIGTERM signal handler and normal term point return the value
-// on TOS so I can do rudimentary automated tests.
/* Decode the IMPs */
switch (ws_code_space[pc++]) {
}
}
break;
- default: ws_die(&pc, "unexpected VTab"); break;
+ default: ws_die(&pc, "unexpected byte"); break;
}
}
-
- printf("\n");
- printf("Program executed.\n");
-
- exit(EXIT_SUCCESS);
}