dotoify.c

#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <getopt.h>
#include <string.h>
#include <libgen.h>
#include <errno.h>
#include <sys/stat.h>

typedef enum OutFormat {
  OUTF_C,
  OUTF_GAS
} OutFormat;

bool y_or_n_p(const char* question, bool y_default)
{ // Yes-or-No prompt. If y_default is true, pressing enter counts as 'Yes',
  // otherwise - as 'No'
  char ch;
  const char* pr;

  if(y_default)
    pr = "[Y/n]";
  else
    pr = "[y/N]";
  printf("%s %s: ", question, pr);
  while(true) {
    ch = getchar();
    switch(ch)
    {
      case 'y':
      case 'Y':
        return true;
      case 'n':
      case 'N':
        return false;
      case '\n':
        if(y_default)
          return true;
        else
          return false;
      default:
        printf("\nSorry, try again: ");
        break;
    }
  }
}

void dashelp(char* progname)
{ // Print help message and exit
  printf(
      "Usage: %s [-h|--help]\n"
      "       %s [[-o|--out] <out-file>] [[-t|--type] <output-type>] " 
              "<files...>\n\n"
      " -h --help  - show this help message\n"
      " -o --out   - write to <out-file> instead of stdout"
      " -t --type  - set output type to <output-type>, which can be `c' or "
                     "`gas'.",
      progname, progname);
  exit(1);
}

void chsub(char* s, char ch1, char ch2)
{ // Substitute each ch1 in string with ch2
  size_t len = strlen(s);

  for(int i = 0; i < len; i++) {
    if(s[i] == ch1)
      s[i] = ch2;
  }
}

char* sympathf(char* path)
{ // Make symbol from pathname. Returned pointer is free'able.
  char* sym = NULL;

  sym = malloc(strlen(basename(path)) + 1);
  if(sym == NULL) {
    fprintf(stderr, "error in sympathf: %s\n", strerror(errno));
    exit(1);
  }
  strcpy(sym, basename(path));
  chsub(sym, '.', '_');
  chsub(sym, '-', '_');
  chsub(sym, '~', '_');
  chsub(sym, ' ', '_');

  return sym;
}

FILE* freopen_wpie(const char* path, FILE* stream)
{ // Create file or open for writing after prompting user if exists already
  errno = 0;
  struct stat st;
  if(stat(path, &st) == 0) {
    if(S_ISREG(st.st_mode)) {
      if(!y_or_n_p("File already exists, overwrite?", false))
        exit(1);
    } else {
      fprintf(stderr, "Error: %s is a directory or special file", path);
      exit(1);
    }
  } else if(errno != ENOENT) {
      fprintf(stderr, "Error when opening file: %s", strerror(errno));
      exit(1);
  }
  stream = freopen(path, "w", stream);
  if(errno != 0) {
    printf("error in `freopen_wpie': %s\n", strerror(errno));
    exit(1);
  }
  return stream;
}

void print_res_block_c(FILE* out, char* path)
{ // Outputs to `out' definions and incbin for resource at `path'.
  char* sym;
  sym = sympathf(path);
  fprintf(out,
        "// file %s\n"
        "extern char res_%s[];\n"
        "extern size_t res_%s_len;\n"
        "asm(\n"
        "  \".data\\n\"\n"
        "  \".global res_%s\\n\"\n"
        "  \".global res_%s_len\\n\"\n"
        "  \"res_%s:\\n\"\n"
        "  \"  .incbin \\\"%s\\\"\\n\"\n"
        "  \"res_%s_len:\\n\"\n"
        "  \"  .quad .-res_%s\\n\"\n"
        ");\n\n",
        path, sym, sym, sym, sym, sym, path, sym, sym
        );
  free(sym);
}

int main(int argc, char** argv)
{
  FILE* out = stdout;
  OutFormat f = OUTF_C;
  
  puts("started...");
  
  if(argc <= 1)
    dashelp(argv[0]);
  while(1) { // Get options
    static struct option opts[] =
    {
      { "help", no_argument, NULL, 'h' },
      { "out", required_argument, NULL, 'o' },
      { "type", required_argument, NULL, 't' },
      { NULL, 0, NULL, 0 }
    };
    int opti;
    int c;

    if((c = getopt_long(argc, argv, "ho:t:", opts, &opti)) == -1)
      break;
    switch(c)
    {
      case 'h':
        dashelp(argv[0]);
        exit(0);
      case 'o':
        out = freopen_wpie(optarg, out);
        break;
      case 't':
        if(strcmp(optarg, "c") == 0)
          f = OUTF_C;
        else if(strcmp(optarg, "gas") == 0)
          f = OUTF_GAS;
        else {
          fprintf(stderr, "Wrong output type. "
              "Can only be either `c' or `gas'\n");
          exit(1);
        }
        break;
    }
  }
  switch(f)
  {
    case OUTF_GAS: // TODO, obviously >___>
      printf("Woops, gas format has yet to be implemented~ =^д^=\n");
      exit(1);
    case OUTF_C:
      fprintf(out,
          "// Generated by DOTOIFY to be compiled with gcc or compatible "
          "compiler.\n"
          "#include <stddef.h>\n\n"
          );
      while(optind < argc) {
        print_res_block_c(out, argv[optind++]);
      }
  }
  if(out != stdout)
    fclose(out);

  return 0;
}