Commit | Line | Data |
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1adfc4f4 AT |
1 | /* |
2 | * (c) 2019 Aaron Taylor <ataylor at subgeniuskitty dot com> | |
3 | * All rights reserved. | |
4 | */ | |
5 | ||
6 | #include <stdio.h> | |
7 | #include <stdlib.h> | |
8 | #include <unistd.h> | |
9 | #include <string.h> | |
10 | #include <errno.h> | |
11 | #include <stdint.h> | |
12 | #include <sys/select.h> | |
13 | #include <getopt.h> | |
14 | ||
15 | #define VERSION 1 | |
16 | ||
17 | #define STACKSIZE 1024 | |
18 | #define HEAPSIZE 1024 | |
19 | #define RETURNSTACKSIZE 1024 | |
20 | ||
21 | void | |
22 | print_usage(char ** argv) | |
23 | { | |
bf43fa3f | 24 | printf( "VVhitespace Interpreter v%d (www.subgeniuskitty.com)\n" |
1adfc4f4 AT |
25 | "Usage: %s -i <file>\n" |
26 | " -h Help (prints this message)\n" | |
bf43fa3f | 27 | " -i <file> Specify a VVhitespace source file to interpret.\n" |
1adfc4f4 AT |
28 | , VERSION, argv[0] |
29 | ); | |
30 | } | |
31 | ||
32 | int | |
33 | stdin_empty(void) | |
34 | { | |
35 | fd_set read_fds; | |
36 | FD_ZERO(&read_fds); | |
37 | FD_SET(STDIN_FILENO, &read_fds); | |
38 | ||
39 | struct timeval timeout; | |
40 | timeout.tv_sec = 0; | |
41 | timeout.tv_usec = 0; | |
42 | ||
43 | int retval = select(1, &read_fds, NULL, NULL, &timeout); | |
44 | /* retval could be -1. Ignoring that for now. */ | |
45 | if (retval > 0) return 0; | |
46 | return 1; | |
47 | } | |
48 | ||
49 | void | |
50 | ws_die(size_t * pc, char * msg) | |
51 | { | |
52 | printf("\n"); | |
53 | printf("SIM_ERROR @ PC %lu: %s\n", *pc, msg); | |
54 | fflush(stdout); | |
55 | exit(EXIT_FAILURE); | |
56 | } | |
57 | ||
58 | void | |
59 | stack_push(int32_t ** sp, int32_t word) | |
60 | { | |
61 | *((*sp)++) = word; | |
62 | } | |
63 | ||
64 | int32_t | |
65 | stack_pop(int32_t ** sp) | |
66 | { | |
67 | return *(--(*sp)); | |
68 | } | |
69 | ||
70 | int32_t | |
71 | stack_peek(int32_t ** sp, size_t offset) | |
72 | /* offset=0 peeks TOS, offset=1 peeks NOS, etc. */ | |
73 | { | |
74 | return *((*sp)-offset-1); | |
75 | } | |
76 | ||
77 | uint8_t | |
78 | next_code_byte(uint8_t * code, size_t * pc) | |
79 | { | |
80 | return code[(*pc)++]; | |
81 | } | |
82 | ||
83 | uint16_t | |
84 | parse_label(uint8_t * code, size_t * pc) | |
85 | { | |
bf43fa3f | 86 | // TODO: Check for invalid label and die. |
1adfc4f4 AT |
87 | uint16_t label = 0; |
88 | uint8_t c; | |
89 | while ((c = code[(*pc)++]) != '\n') { | |
90 | label = label << 1; | |
91 | if (c == ' ') label++; | |
92 | } | |
93 | return label; | |
94 | } | |
95 | ||
bf43fa3f AT |
96 | void |
97 | populate_labels(uint32_t * labels, uint8_t * code, size_t code_size) | |
98 | { | |
99 | // TODO | |
100 | } | |
101 | ||
1adfc4f4 AT |
102 | void |
103 | process_imp_stack(uint8_t * code, size_t * pc, int32_t ** sp) | |
104 | { | |
105 | switch (next_code_byte(code,pc)) { | |
106 | case ' ': | |
107 | /* Push number onto TOS. */ | |
108 | { | |
109 | /* First, pick off the sign */ | |
110 | int32_t sign = 0; | |
111 | switch (next_code_byte(code,pc)) { | |
112 | case ' ' : sign = 1; break; | |
113 | case '\t': sign = -1; break; | |
bf43fa3f | 114 | default : ws_die(pc, "expected sign"); break; |
1adfc4f4 AT |
115 | } |
116 | ||
117 | /* Now, construct the number and push to TOS. */ | |
118 | /* I'm assuming the numbers are read MSb first. */ | |
119 | int32_t temp, number = 0; | |
120 | while ((temp = next_code_byte(code,pc)) != '\n') { | |
bf43fa3f | 121 | if (temp == '\v') ws_die(pc, "non-binary digit in number"); |
1adfc4f4 AT |
122 | number <<= 1; |
123 | if (temp == '\t') number++; | |
124 | } | |
125 | stack_push(sp, number*sign); | |
126 | } | |
127 | break; | |
128 | case '\n': | |
129 | /* Stack sub-command */ | |
130 | { | |
131 | switch (next_code_byte(code,pc)) { | |
132 | /* Duplicate the TOS. */ | |
133 | case ' ': | |
134 | stack_push(sp, stack_peek(sp,0)); | |
135 | break; | |
136 | /* Swap TOS and NOS. */ | |
137 | case '\t': | |
138 | { | |
139 | int32_t t1 = stack_pop(sp); | |
140 | int32_t t2 = stack_pop(sp); | |
141 | stack_push(sp, t1); | |
142 | stack_push(sp, t2); | |
143 | } | |
144 | break; | |
145 | /* Discard TOS. */ | |
146 | case '\n': | |
147 | stack_pop(sp); | |
148 | break; | |
bf43fa3f AT |
149 | default: |
150 | ws_die(pc, "malformed stack IMP"); | |
151 | break; | |
1adfc4f4 AT |
152 | } |
153 | } | |
154 | break; | |
bf43fa3f | 155 | default: ws_die(pc, "malformed stack IMP"); break; |
1adfc4f4 AT |
156 | } |
157 | } | |
158 | ||
159 | void | |
160 | process_imp_arithmetic(uint8_t * code, size_t * pc, int32_t ** sp) | |
161 | { | |
162 | int32_t temp; | |
163 | switch (next_code_byte(code,pc)) { | |
164 | case ' ': | |
165 | { | |
166 | switch (next_code_byte(code,pc)) { | |
167 | case ' ': | |
168 | /* Addition */ | |
169 | stack_push(sp, stack_pop(sp)+stack_pop(sp)); | |
170 | break; | |
171 | case '\t': | |
172 | /* Subtraction */ | |
173 | temp = stack_pop(sp); | |
174 | stack_push(sp, stack_pop(sp)-temp); | |
175 | break; | |
176 | case '\n': | |
177 | /* Multiplication */ | |
178 | stack_push(sp, stack_pop(sp)*stack_pop(sp)); | |
179 | break; | |
bf43fa3f AT |
180 | default: |
181 | ws_die(pc, "malformed arithmetic IMP"); | |
182 | break; | |
1adfc4f4 AT |
183 | } |
184 | } | |
185 | break; | |
186 | case '\t': | |
187 | { | |
188 | switch (next_code_byte(code,pc)) { | |
189 | case ' ': | |
190 | /* Division */ | |
191 | temp = stack_pop(sp); | |
192 | stack_push(sp, stack_pop(sp)/temp); | |
193 | break; | |
194 | case '\t': | |
195 | /* Modulo */ | |
196 | temp = stack_pop(sp); | |
197 | stack_push(sp, stack_pop(sp)%temp); | |
198 | break; | |
bf43fa3f | 199 | default: ws_die(pc, "malformed arithmetic IMP"); break; |
1adfc4f4 AT |
200 | } |
201 | } | |
202 | break; | |
bf43fa3f | 203 | default: ws_die(pc, "malformed arithmetic IMP"); break; |
1adfc4f4 AT |
204 | } |
205 | } | |
206 | ||
207 | void | |
208 | process_imp_flowcontrol(uint8_t * code, size_t * pc, int32_t ** sp, uint32_t * labels, | |
209 | uint32_t ** rsp) | |
210 | { | |
211 | switch (next_code_byte(code,pc)) { | |
212 | case '\n': | |
213 | /* Technically another LF is required but we ignore it. */ | |
214 | printf("\n"); | |
215 | fflush(stdout); | |
216 | exit(EXIT_SUCCESS); | |
217 | case ' ': | |
218 | { | |
219 | switch (next_code_byte(code,pc)) { | |
220 | case ' ': | |
221 | /* Mark a location in the program. */ | |
bf43fa3f | 222 | // TODO: Verify this is a label, but do nothing else. |
1adfc4f4 AT |
223 | labels[parse_label(code, pc)] = *pc; |
224 | break; | |
225 | case '\t': | |
226 | /* Call a subroutine. */ | |
227 | *((*rsp)++) = *pc; | |
228 | *pc = labels[parse_label(code, pc)]; | |
229 | break; | |
230 | case '\n': | |
231 | /* Jump unconditionally to a label. */ | |
232 | *pc = labels[parse_label(code, pc)]; | |
233 | break; | |
bf43fa3f AT |
234 | default: |
235 | ws_die(pc, "malformed flow control IMP"); | |
236 | break; | |
1adfc4f4 AT |
237 | } |
238 | } | |
239 | break; | |
240 | case '\t': | |
241 | { | |
242 | switch (next_code_byte(code,pc)) { | |
243 | case ' ': | |
244 | /* Jump to a label if TOS == 0 */ | |
245 | if (stack_peek(sp,0) == 0) *pc = labels[parse_label(code, pc)]; | |
246 | break; | |
247 | case '\t': | |
248 | /* Jump to a label if TOS < 0. */ | |
249 | if (stack_peek(sp,0) < 0) *pc = labels[parse_label(code, pc)]; | |
250 | break; | |
251 | case '\n': | |
252 | /* Return from subroutine. */ | |
253 | *pc = *(--(*rsp)); | |
254 | break; | |
bf43fa3f AT |
255 | default: |
256 | ws_die(pc, "malformed flow control IMP"); | |
257 | break; | |
1adfc4f4 AT |
258 | } |
259 | } | |
260 | break; | |
bf43fa3f AT |
261 | default: |
262 | ws_die(pc, "malformed flow control IMP"); | |
263 | break; | |
1adfc4f4 AT |
264 | } |
265 | } | |
266 | ||
267 | void | |
268 | process_imp_heap(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp) | |
269 | { | |
270 | switch (next_code_byte(code,pc)) { | |
271 | case ' ' : /* Store to heap */ *(*hp + *((*sp)-1)) = **sp; *sp -= 2; break; | |
272 | case '\t': /* Retrieve from heap */ **sp = *(*hp + **sp); break; | |
bf43fa3f | 273 | default: ws_die(pc, "malformed heap IMP"); break; |
1adfc4f4 AT |
274 | } |
275 | } | |
276 | ||
277 | void | |
278 | process_imp_io(uint8_t * code, size_t * pc, int32_t ** sp, int32_t ** hp) | |
279 | { | |
280 | switch (next_code_byte(code,pc)) { | |
281 | case ' ': | |
282 | /* Output */ | |
283 | { | |
284 | switch (next_code_byte(code,pc)) { | |
285 | case ' ' : /* Output character from TOS */ printf("%c", stack_pop(sp)); break; | |
286 | case '\t': /* Output number from TOS */ printf("%d", stack_pop(sp)); break; | |
bf43fa3f | 287 | default: ws_die(pc, "malformed output IMP"); break; |
1adfc4f4 AT |
288 | } |
289 | fflush(stdout); | |
290 | } | |
291 | break; | |
292 | case '\t': | |
293 | /* Input */ | |
294 | { | |
295 | while (stdin_empty()) continue; | |
296 | char c = getchar(); | |
297 | switch (next_code_byte(code,pc)) { | |
298 | case '\t': /* Input digit */ c -= '0'; /* fallthrough */ | |
299 | case ' ' : /* Input character */ *(*hp + *((*sp)--)) = c; break; | |
bf43fa3f | 300 | default: ws_die(pc, "malformed input IMP"); break; |
1adfc4f4 AT |
301 | } |
302 | } | |
303 | break; | |
bf43fa3f | 304 | default: ws_die(pc, "malformed i/o IMP"); break; |
1adfc4f4 AT |
305 | } |
306 | } | |
307 | ||
1adfc4f4 AT |
308 | int |
309 | main(int argc, char ** argv) | |
310 | { | |
311 | /* | |
312 | * Process command line arguments | |
313 | */ | |
314 | int c; | |
315 | FILE * input = NULL; | |
316 | while ((c = getopt(argc,argv,"i:h")) != -1) { | |
317 | switch (c) { | |
318 | case 'i': | |
319 | if ((input = fopen(optarg, "r")) == NULL) { | |
320 | fprintf(stderr, "ERROR: %s: %s\n", optarg, strerror(errno)); | |
321 | } | |
322 | break; | |
323 | case 'h': | |
324 | print_usage(argv); | |
325 | exit(EXIT_SUCCESS); | |
326 | break; | |
327 | default: | |
328 | break; | |
329 | } | |
330 | } | |
331 | if (input == NULL) { | |
bf43fa3f | 332 | fprintf(stderr, "ERROR: Must specify a VVhitespace source file with -f flag.\n"); |
1adfc4f4 AT |
333 | print_usage(argv); |
334 | exit(EXIT_FAILURE); | |
335 | } | |
336 | ||
337 | /* | |
bf43fa3f | 338 | * Read just the VVhitespace source code into memory. |
1adfc4f4 AT |
339 | * We will use the array indices as addresses for the virtual PC when jumping to labels. |
340 | */ | |
341 | size_t ws_code_size = 0; | |
342 | uint8_t temp_byte; | |
343 | while (fread(&temp_byte, 1, 1, input)) { | |
bf43fa3f AT |
344 | if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') { |
345 | ws_code_size++; | |
346 | } | |
1adfc4f4 AT |
347 | } |
348 | rewind(input); | |
349 | uint8_t * ws_code_space = malloc(ws_code_size); | |
350 | ws_code_size = 0; | |
351 | while (fread(&temp_byte, 1, 1, input)) { | |
bf43fa3f AT |
352 | if (temp_byte == ' ' || temp_byte == '\t' || temp_byte == '\n' || temp_byte == '\v') { |
353 | ws_code_space[ws_code_size++] = temp_byte; | |
354 | } | |
1adfc4f4 AT |
355 | } |
356 | fclose(input); | |
357 | ||
358 | /* | |
359 | * Setup a stack and heap. | |
360 | * Assume a 32-bit word size. | |
361 | */ | |
bf43fa3f | 362 | // TODO: Make everything 64-bit. |
1adfc4f4 AT |
363 | int32_t * hp = malloc(HEAPSIZE*4); |
364 | int32_t * sp = malloc(STACKSIZE*4); | |
365 | ||
366 | /* | |
367 | * Setup the return stack and the label array. | |
368 | */ | |
369 | uint32_t * rsp = malloc(RETURNSTACKSIZE*4); | |
bf43fa3f AT |
370 | uint32_t labels[65536] = {0}; |
371 | populate_labels(labels, ws_code_space, ws_code_size); | |
1adfc4f4 AT |
372 | |
373 | /* | |
374 | * Main Loop | |
375 | */ | |
376 | ||
377 | size_t pc = 0; /* Virtual program counter. Operates in the ws_code_space[] address space. */ | |
378 | while (1) { | |
379 | if (pc >= ws_code_size) { | |
bf43fa3f AT |
380 | fprintf(stderr, "SIM_ERROR: PC Overrun\n Requested PC: %lu\n Max Address: %lu\n", |
381 | pc, ws_code_size-1); | |
1adfc4f4 AT |
382 | exit(EXIT_FAILURE); |
383 | } | |
384 | ||
385 | /* Decode the IMPs */ | |
386 | switch (ws_code_space[pc++]) { | |
387 | case ' ': | |
388 | /* Stack Manipulation */ | |
389 | process_imp_stack(ws_code_space, &pc, &sp); | |
390 | break; | |
391 | case '\n': | |
392 | /* Flow Control */ | |
393 | process_imp_flowcontrol(ws_code_space, &pc, &sp, labels, &rsp); | |
394 | break; | |
395 | case '\t': | |
396 | /* Arithmetic, Heap Access, or I/O */ | |
397 | { | |
398 | switch (ws_code_space[pc++]) { | |
399 | case ' ': | |
400 | /* Arithmetic */ | |
401 | process_imp_arithmetic(ws_code_space, &pc, &sp); | |
402 | break; | |
403 | case '\t': | |
404 | /* Heap Access */ | |
405 | process_imp_heap(ws_code_space, &pc, &sp, &hp); | |
406 | break; | |
407 | case '\n': | |
408 | /* I/O */ | |
409 | process_imp_io(ws_code_space, &pc, &sp, &hp); | |
410 | break; | |
411 | } | |
412 | } | |
413 | break; | |
bf43fa3f | 414 | default: ws_die(pc, "unexpected VTab"); break; |
1adfc4f4 AT |
415 | } |
416 | } | |
417 | ||
418 | printf("\n"); | |
419 | printf("Program executed.\n"); | |
420 | ||
421 | exit(EXIT_SUCCESS); | |
422 | } |