fix-header.c

gcc库的原代码,对编程有很大帮助.

  if (isalpha (c) || c == '_')
    {
      for (;;)
	{
	  SSTRING_PUT (s, c);
	  c = INF_GET ();
	  if (c == EOF || !(isalnum (c) || c == '_'))
	    break;
	}
    }
  MAKE_SSTRING_SPACE (s, 1);
  *s->ptr = 0;
  return c;
}

/* Returns 1 if the file is correctly protected against multiple
   inclusion, setting *ifndef_line to the line number of the initial #ifndef
   and setting *endif_line to the final #endif.
   Otherwise return 0. */

int
check_protection (ifndef_line, endif_line)
     int *ifndef_line, *endif_line;
{
  int c;
  int if_nesting = 1; /* Level of nesting of #if's */
  char *protect_name = NULL; /* Identifier following initial #ifndef */
  int define_seen = 0;

  /* Skip initial white space (including comments). */
  for (;; lineno++)
    {
      c = inf_skip_spaces (' ');
      if (c == EOF)
	return 0;
      if (c != '\n')
	break;
    }
  if (c != '#')
    return 0;
  c = inf_scan_ident (&buf, inf_skip_spaces (' '));
  if (SSTRING_LENGTH (&buf) == 0 || strcmp (buf.base, "ifndef") != 0)
    return 0;

  /* So far so good: We've seen an initial #ifndef. */
  *ifndef_line = lineno;
  c = inf_scan_ident (&buf, inf_skip_spaces (c));
  if (SSTRING_LENGTH (&buf) == 0 || c == EOF)
    return 0;
  protect_name = xstrdup (buf.base);

  INF_UNGET (c);
  c = inf_read_upto (&buf, '\n');
  if (c == EOF)
    return 0;
  lineno++;

  for (;;)
    {
      c = inf_skip_spaces (' ');
      if (c == EOF)
	return 0;
      if (c == '\n')
	{
	  lineno++;
	  continue;
	}
      if (c != '#')
	goto skip_to_eol;
      c = inf_scan_ident (&buf, inf_skip_spaces (' '));
      if (SSTRING_LENGTH (&buf) == 0)
	;
      else if (!strcmp (buf.base, "ifndef")
	  || !strcmp (buf.base, "ifdef") || !strcmp (buf.base, "if"))
	{
	  if_nesting++;
	}
      else if (!strcmp (buf.base, "endif"))
	{
	  if_nesting--;
	  if (if_nesting == 0)
	    break;
	}
      else if (!strcmp (buf.base, "else"))
	{
	  if (if_nesting == 1)
	    return 0;
	}
      else if (!strcmp (buf.base, "define"))
	{
	  if (if_nesting != 1)
	    goto skip_to_eol;
	  c = inf_skip_spaces (c);
	  c = inf_scan_ident (&buf, c);
	  if (buf.base[0] > 0 && strcmp (buf.base, protect_name) == 0)
	    define_seen = 1;
	}
    skip_to_eol:
      for (;;)
	{
	  if (c == '\n' || c == EOF)
	    break;
	  c = INF_GET ();
	}
      if (c == EOF)
	return 0;
      lineno++;
    }

  if (!define_seen)
     return 0;
  *endif_line = lineno;
  /* Skip final white space (including comments). */
  for (;;)
    {
      c = inf_skip_spaces (' ');
      if (c == EOF)
	break;
      if (c != '\n')
	return 0;
    }

  return 1;
}

int
main (argc, argv)
     int argc;
     char **argv;
{
  int inf_fd;
  struct stat sbuf;
  int c;
  int i, done;
  const char *cptr, **pptr;
  int ifndef_line;
  int endif_line;
  long to_read;
  long int inf_size;

  if (argv[0] && argv[0][0])
    {
      register char *p;

      progname = 0;
      for (p = argv[0]; *p; p++)
        if (*p == '/')
          progname = p;
      progname = progname ? progname+1 : argv[0];
    }

  if (argc < 4)
    {
      fprintf (stderr, "%s: Usage: foo.h infile.h outfile.h options\n",
	       progname);
      exit (-1);
    }

  inc_filename = argv[1];
  inc_filename_length = strlen (inc_filename);

#ifdef FIXPROTO_IGNORE_LIST
  for (i = 0; files_to_ignore[i] != NULL; i++)
    {
      char *ignore_name = files_to_ignore[i];
      int ignore_len = strlen (ignore_name);
      if (strncmp (inc_filename, ignore_name, ignore_len) == 0)
	{
	  if (ignore_name[ignore_len-1] == '/'
	      || inc_filename[ignore_len] == '\0')
	    {
	      if (verbose)
		fprintf (stderr, "%s: ignoring %s\n", progname, inc_filename);
	      exit (0);
	    }
	}
	  
    }
#endif

  if (strcmp (inc_filename, "sys/stat.h") == 0)
    special_file_handling = sys_stat_h;
  else if (strcmp (inc_filename, "errno.h") == 0)
    special_file_handling = errno_h, missing_errno = 1;
  else if (strcmp (inc_filename, "stdio.h") == 0)
    special_file_handling = stdio_h;
  include_entry = std_include_table;
  while (include_entry->name != NULL
	 && strcmp (inc_filename, include_entry->name) != 0)
    include_entry++;

  required_functions_list = include_entry->required;

  /* Count and mark the prototypes required for this include file. */ 
  for (cptr = required_functions_list; *cptr!= '\0'; )
    {
      int name_len = strlen (cptr);
      struct fn_decl *fn = lookup_std_proto (cptr, name_len);
      required_unseen_count++;
      if (fn == NULL)
	fprintf (stderr, "Internal error:  No prototype for %s\n", cptr);
      else
	SET_REQUIRED (fn);
      cptr += name_len + 1;
    }

  read_scan_file (argv[2], argc - 4, argv + 4);

  inf_fd = open (argv[2], O_RDONLY, 0666);
  if (inf_fd < 0)
    {
      fprintf (stderr, "%s: Cannot open '%s' for reading -",
	       progname, argv[2]);
      perror (NULL);
      exit (-1);
    }
  if (fstat (inf_fd, &sbuf) < 0)
    {
      fprintf (stderr, "%s: Cannot get size of '%s' -", progname, argv[2]);
      perror (NULL);
      exit (-1);
    }
  inf_size = sbuf.st_size;
  inf_buffer = (char*) xmalloc (inf_size + 2);
  inf_buffer[inf_size] = '\n';
  inf_buffer[inf_size + 1] = '\0';
  inf_limit = inf_buffer + inf_size;
  inf_ptr = inf_buffer;

  to_read = inf_size;
  while (to_read > 0)
    {
      long i = read (inf_fd, inf_buffer + inf_size - to_read, to_read);
      if (i < 0)
	{
	  fprintf (stderr, "%s: Failed to read '%s' -", progname, argv[2]);
	  perror (NULL);
	  exit (-1);
	}
      if (i == 0)
	{
	  inf_size -= to_read;
	  break;
	}
      to_read -= i;
    }

  close (inf_fd);

  /* If file doesn't end with '\n', add one. */
  if (inf_limit > inf_buffer && inf_limit[-1] != '\n')
    inf_limit++;

  unlink (argv[3]);
  outf = fopen (argv[3], "w");
  if (outf == NULL)
    {
      fprintf (stderr, "%s: Cannot open '%s' for writing -",
	       progname, argv[3]);
      perror (NULL);
      exit (-1);
    }

  lineno = 1;

  if (check_protection (&ifndef_line, &endif_line))
    {
      lbrac_line = ifndef_line+1;
      rbrac_line = endif_line;
    }
  else
    {
      lbrac_line = 1;
      rbrac_line = -1;
    }

  /* Reset input file. */
  inf_ptr = inf_buffer;
  lineno = 1;

  for (;;)
    {
      if (lineno == lbrac_line)
	write_lbrac ();
      if (lineno == rbrac_line)
	write_rbrac ();
      for (;;)
	{
	  struct fn_decl *fn;
	  c = INF_GET ();
	  if (c == EOF)
	    break;
	  if (isalpha (c) || c == '_')
	    {
	      c = inf_scan_ident (&buf, c);
	      INF_UNGET (c);
	      fputs (buf.base, outf);
	      fn = lookup_std_proto (buf.base, strlen (buf.base));
	      /* We only want to edit the declaration matching the one
		 seen by scan-decls, as there can be multiple
		 declarations, selected by #ifdef __STDC__ or whatever. */
	      if (fn && fn->partial && fn->partial->line_seen == lineno)
		{
		  c = inf_skip_spaces (' ');
		  if (c == EOF)
		    break;
		  if (c == '(')
		    {
		      c = inf_skip_spaces (' ');
		      if (c == ')')
			{
			  fprintf (outf, " _PARAMS((%s))", fn->params);
			}
		      else
			{
			  putc ('(', outf);
			  INF_UNGET (c);
			}
		    }
		  else
		    fprintf (outf, " %c", c);
		}
	    }
	  else
	    {
	      putc (c, outf);
	      if (c == '\n')
		break;
	    }
	}
      if (c == EOF)
	break;
      lineno++;
    }
  if (rbrac_line < 0)
    write_rbrac ();

  fclose (outf);

  return 0;
}

/* Stub error functions.  These replace cpperror.c,
   because we want to suppress error messages. */

void
cpp_file_line_for_message (pfile, filename, line, column)
     cpp_reader *pfile;
     char *filename;
     int line, column;
{
  if (!verbose)
    return;
  if (column > 0)
    fprintf (stderr, "%s:%d:%d: ", filename, line, column);
  else
    fprintf (stderr, "%s:%d: ", filename, line);
}

void
cpp_print_containing_files (pfile)
     cpp_reader *pfile;
{
}

/* IS_ERROR is 1 for error, 0 for warning */
void cpp_message (pfile, is_error, msg, arg1, arg2, arg3)
     int is_error;
     cpp_reader *pfile;
     char *msg;
     char *arg1, *arg2, *arg3;
{
  if (is_error)
    pfile->errors++;
  if (!verbose)
    return;
  if (!is_error)
    fprintf (stderr, "warning: ");
  fprintf (stderr, msg, arg1, arg2, arg3);
  fprintf (stderr, "\n");
}

void
fatal (str, arg)
     char *str, *arg;
{
  fprintf (stderr, "%s: %s: ", progname, inc_filename);
  fprintf (stderr, str, arg);
  fprintf (stderr, "\n");
  exit (FATAL_EXIT_CODE);
}

void
cpp_pfatal_with_name (pfile, name)
     cpp_reader *pfile;
     char *name;
{
  cpp_perror_with_name (pfile, name);
  exit (FATAL_EXIT_CODE);
}