diff options
| -rw-r--r-- | README | 0 | ||||
| -rw-r--r-- | brainfuck.c | 250 | ||||
| -rw-r--r-- | hello.bf | 4 |
3 files changed, 254 insertions, 0 deletions
diff --git a/brainfuck.c b/brainfuck.c new file mode 100644 index 0000000..ba573db --- /dev/null +++ b/brainfuck.c @@ -0,0 +1,250 @@ +/* + * gcc -ansi -pedantic -Wall -Wextra -Werror -o brainfuck brainfuck.c + */ + +#include <stdlib.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <getopt.h> + +#define DATATYPE int + +FILE * prog; + +char * code = NULL; +DATATYPE * data = NULL; +unsigned int * stack = NULL; + +unsigned int data_size = 30000; +unsigned int stack_size = 128; + +char format = 'u'; + +unsigned int cp = 0; +unsigned int dp = 0; +unsigned int sp = 0; + +void read_code() +{ + int allocated, n, c; + + allocated = 1000; + n = 0; + + code = (char*) malloc(allocated * sizeof(char)); + while (EOF != (c = getc(prog))) + { + if (n >= allocated) + { + allocated <<= 1; + code = (char*) realloc(code, allocated * sizeof(char)); + } + code[n++] = (char) c; + } + + if (n >= allocated) + { + allocated <<= 1; + code = (char*) realloc(code, allocated * sizeof(char)); + } + code[n++] = '\0'; +} + +void init_data() +{ + data = (DATATYPE*) calloc(data_size, sizeof(DATATYPE)); +} + +void init_stack() +{ + stack = (unsigned int*) malloc(stack_size); +} + + +int inc_dp() +{ + if (dp < data_size) + { + ++dp; + return 1; + } + else + { + fprintf(stderr, "Data overflow\n"); + return 0; + } +} + +void dec_dp() +{ + if (dp > 0) + --dp; + else + fprintf(stderr, "Data underflow\n"); +} + + +void push_cp() +{ + if (sp < stack_size) + stack[sp++] = cp; + else + fprintf(stderr, "Stack overflow\n"); +} + +void pop_cp() +{ + if (sp > 0) + cp = stack[--sp]; + else + fprintf(stderr, "Stack underflow\n"); +} + +int skip() +{ + while (code[cp] != '\0') + { + if (code[++cp] == ']') + return 1; + } + return 0; +} + + +void print() +{ + switch (format) + { + case 'i': printf("%i\n", data[dp]); break; + case 'u': printf("%u\n", data[dp]); break; + case 'c': printf("%c", data[dp]); break; + case 'o': printf("0%o\n", data[dp]); break; + case 'x': printf("0x%X\n", data[dp]); break; + } +} + +void run_code() +{ + char cmd; + while ('\0' != (cmd = code[cp])) + { + /*fprintf(stderr, "%c", cmd);*/ + switch (cmd) + { + case '[': if (data[dp]) + { + push_cp(); ++cp; + } + else + { + skip(); ++cp; + } + break; + case ']': pop_cp(); break; + case '+': ++(data[dp]); ++cp; break; + case '-': --(data[dp]); ++cp; break; + case '>': inc_dp(); ++cp; break; + case '<': dec_dp(); ++cp; break; + case '.': print(); ++cp; break; + + case 'i': + case 'u': + case 'c': + case 'o': + case 'x': + format = cmd; ++cp; break; + default: ++cp; + } + } +} + +void free_all() +{ + if (code != NULL) free(code); + if (data != NULL) free(data); + if (stack != NULL) free(stack); +} + +void usage(char * self) +{ + printf("%s: Brainfuck programming language interpreter\n", self); + printf("See http://en.wikipedia.org/wiki/Brainfuck for more details\n\n"); + + printf("Usage: %s [options] [file]\n\n", self); + + printf("Size of each data cell is %u byte(s)\n\n", sizeof(DATATYPE)); + printf("Options (defaults are in brackets):\n"); + printf(" -s num stack size (%u)\n", stack_size); + printf(" -d num data size (%u)\n", data_size); + printf("\n"); + printf("Output formats for operator '.':\n"); + printf(" -c, -i, -u, -o, -x char, signed int, unsigned int, octal, hexadecimal\n"); + printf("\n"); + printf(" -h this help message\n"); + printf("\n"); + printf(" file file to execute,\n"); + printf(" if omitted read stdin\n"); + printf("\n"); + printf("Standard operators: <>+-[].,\n"); + printf("Extensions: ciuox - change format output (same as -c & others, see above)\n"); + printf("\n"); + printf("Example:\n"); + printf(" echo '+++[.-]' | %s\n", self); + + exit(EXIT_SUCCESS); +} + +int main(int argc, char ** argv) +{ + char * filename; + char * self = argv[0]; + int opt; + + while (-1 != (opt = getopt(argc, argv, "s:d:h?iucox"))) + { + switch (opt) + { + case 's': + sscanf(optarg, "%u", &stack_size); + break; + case 'd': + sscanf(optarg, "%u", &data_size); + break; + case 'i': + case 'u': + case 'c': + case 'o': + case 'x': + format = opt; + break; + default: usage(self); + } + } + + if (optind < argc) + { + filename = argv[optind]; + if (NULL == (prog = fopen(filename, "r"))) + { + fprintf(stderr, "%s: open '%s': %s\n", self, filename, strerror(errno)); + exit(EXIT_FAILURE); + } + } + else + prog = stdin; + + read_code(); + + if (prog != stdin) + fclose(prog); + + init_data(); + init_stack(); + + run_code(); + + free_all(); + return 0; +} + diff --git a/hello.bf b/hello.bf new file mode 100644 index 0000000..a2fce2b --- /dev/null +++ b/hello.bf @@ -0,0 +1,4 @@ +c++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++ +.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++. +------.--------.>+.>. + |