hwc.c

   1 /* Hello world program compiler */
   2 #include <ctype.h>
   3 #include <stdarg.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "vm.h"
   9
  10 static int parse(FILE *, FILE *);
  11 static void write_hw_header(FILE *, int);
  12 static HwInstruction *get_instr(int);
  13 static void compiler_error(const char *, ...);
  14
  15 int
  16 main(int argc, char *argv[])
  17 {
  18     FILE *in, *out;
  19     int in_count;
  20     char *file_name = NULL;
  21     if (argc == 1)
  22        compiler_error("No input files!\n");
  23
  24     file_name = argv[1];
  25     in = fopen(file_name, "rt");
  26     if (in == NULL)
  27         compiler_error("Cannot open file %s\n", file_name);
  28
  29     file_name[strlen(file_name)-1] = 'x';
  30     out = fopen(file_name, "wb");
  31     if (out == NULL)
  32         compiler_error("Cannot open file %s\n", file_name);
  33
  34     fseek(out, sizeof(HwHeader), SEEK_SET);
  35     in_count = parse(in, out);
  36     write_hw_header(out, in_count);
  37
  38     fclose(in);
  39     fclose(out);
  40     return 0;
  41 }
  42
  43 static int
  44 parse(FILE *in, FILE *out)
  45 {
  46     int input;
  47     int i, count = 0;
  48     int is_comment = 0;
  49     HwInstruction *inst = NULL;
  50
  51     while (!feof(in)) {
  52         fscanf(in, "%c", (char *)&input);
  53
  54         switch (input) {
  55             case '#' :
  56             is_comment = 1;
  57             continue;
  58
  59             case '\n' :
  60             is_comment = 0;
  61             continue;
  62         }
  63
  64         if (is_comment)
  65             continue;
  66
  67         if (!isalpha(input))
  68             continue;
  69
  70         inst = get_instr(input);
  71         if (inst == NULL)
  72             continue;
  73
  74         fwrite((void *)&inst->i_opcode, sizeof(uint8_t), 1, out);
  75         count++;
  76     }
  77     return count;
  78 }
  79
  80 static void
  81 write_hw_header(FILE *out, int count)
  82 {
  83     HwHeader head = {
  84            .hw_magic = HW_HEADER_MAGIC,
  85            .hw_version = HW_HEADER_VERSION,
  86            .hw_instr_count = count
  87     };
  88
  89     fseek(out, 0L, SEEK_SET);
  90     fwrite(&head, sizeof(HwHeader), 1, out);
  91 }
  92
  93 static HwInstruction *
  94 get_instr(int inst)
  95 {
  96     int i;
  97     HwInstruction *hi = NULL;
  98     for (i = 0; i < LAST_INSTRUCTION; i++) {
  99        if (instructions[i].i_char == inst) {
 100            hi = &instructions[i];
 101            return hi;
 102        }
 103     }
 104     return NULL;
 105 }
 106
 107 static void
 108 compiler_error(const char *fmt, ...)
 109 {
 110     va_list ap;
 111     va_start(ap, fmt);
 112     fprintf(stderr, "HW Compiler - (C) Akos Kovacs\n\nError: ");
 113     vfprintf(stderr, fmt, ap);
 114     va_end(ap);
 115     exit(1);
 116 }