fix-header.c

gcc库的原代码,对编程有很大帮助.

void
recognized_extern (name, name_length, type, type_length)
     char *name;
     char *type;
     int name_length, type_length;
{
  switch (special_file_handling)
    {
    case errno_h:
      if (strncmp (name, "errno", name_length) == 0) missing_errno = 0;
      break;
    }
}

/* Called by scan_decls if it saw a function definition for a function
   named FNAME, with return type RTYPE, and argument list ARGS,
   in source file FILE_SEEN on line LINE_SEEN.
   KIND is 'I' for an inline function;
   'F' if a normal function declaration preceded by 'extern "C"'
   (or nested inside 'extern "C"' braces); or
   'f' for other function declarations. */

void
recognized_function (fname, fname_length,
		     kind, rtype, rtype_length,
		     have_arg_list, file_seen, line_seen)
     char *fname;
     int fname_length;
     int kind; /* One of 'f' 'F' or 'I' */
     char *rtype;
     int rtype_length;
     int have_arg_list;
     char *file_seen;
     int line_seen;
{
  struct partial_proto *partial;
  int i;
  struct fn_decl *fn;
#if ADD_MISSING_EXTERN_C
  if (kind == 'f')
    missing_extern_C_count++;
#endif

  fn = lookup_std_proto (fname, fname_length);

  /* Remove the function from the list of required function. */
  if (fn)
    {
      if (REQUIRED (fn))
	required_unseen_count--;
      SET_SEEN (fn);
    }

  /* If we have a full prototype, we're done. */
  if (have_arg_list)
    return;
      
  if (kind == 'I')  /* don't edit inline function */
    return;

  /* If the partial prototype was included from some other file,
     we don't need to patch it up (in this run). */
  i = strlen (file_seen);
  if (i < inc_filename_length
      || strcmp (inc_filename, file_seen + (i - inc_filename_length)) != 0)
    return;

  if (fn == NULL)
    return;
  if (fn->params[0] == '\0' || strcmp (fn->params, "void") == 0)
    return;

  /* We only have a partial function declaration,
     so remember that we have to add a complete prototype. */
  partial_count++;
  partial = (struct partial_proto*)
    obstack_alloc (&scan_file_obstack, sizeof (struct partial_proto));
  partial->fname = obstack_alloc (&scan_file_obstack, fname_length + 1);
  bcopy (fname, partial->fname, fname_length);
  partial->fname[fname_length] = 0;
  partial->rtype = obstack_alloc (&scan_file_obstack, rtype_length + 1);
  sprintf (partial->rtype, "%.*s", rtype_length, rtype);
  partial->line_seen = line_seen;
  partial->fn = fn;
  fn->partial = partial;
  partial->next = partial_proto_list;
  partial_proto_list = partial;
  if (verbose)
    {
      fprintf (stderr, "(%s: %s non-prototype function declaration.)\n",
	       inc_filename, partial->fname);
    }
}

/* For any name in NAMES that is defined as a macro,
   call recognized_macro on it. */

void
check_macro_names (pfile, names)
     struct parse_file *pfile;
     namelist names;
{
  while (*names)
    {
      if (cpp_lookup (pfile, names, -1, -1))
	recognized_macro (names);
      names += strlen (names) + 1;
    }
}

void
read_scan_file (in_fname, argc, argv)
     char *in_fname;
     int argc;
     char **argv;
{
  cpp_reader scan_in;
  cpp_options scan_options;
  struct fn_decl *fn;
  int i;

  obstack_init (&scan_file_obstack); 

  init_parse_file (&scan_in);
  scan_in.data = &scan_options;
  init_parse_options (&scan_options);
  i = cpp_handle_options (&scan_in, argc, argv);
  if (i < argc)
    fatal ("Invalid option `%s'", argv[i]);
  push_parse_file (&scan_in, in_fname);
  CPP_OPTIONS (&scan_in)->no_line_commands = 1;

  scan_decls (&scan_in, argc, argv);
  check_macro_names (&scan_in, include_entry->required);
  check_macro_names (&scan_in, include_entry->extra);

  if (verbose && (scan_in.errors + warnings) > 0)
    fprintf (stderr, "(%s: %d errors and %d warnings from cpp)\n",
	     inc_filename, scan_in.errors, warnings);
  if (scan_in.errors)
    exit (0);

  /* Traditionally, getc and putc are defined in terms of _filbuf and _flsbuf.
     If so, those functions are also required. */
  if (special_file_handling == stdio_h
      && (fn = lookup_std_proto ("_filbuf", 7)) != NULL)
    {
      static char getchar_call[] = "getchar();";
      cpp_buffer *buf =
	cpp_push_buffer (&scan_in, getchar_call, sizeof(getchar_call) - 1);
      int old_written = CPP_WRITTEN (&scan_in);
      int seen_filbuf = 0;

      /* Scan the macro expansion of "getchar();". */
      for (;;)
	{
	  enum cpp_token token = cpp_get_token (&scan_in);
	  int length = CPP_WRITTEN (&scan_in) - old_written;
	  CPP_SET_WRITTEN (&scan_in, old_written);
	  if (token == CPP_EOF) /* Should not happen ... */
	    break;
	  if (token == CPP_POP && CPP_BUFFER (&scan_in) == buf)
	    {
	      cpp_pop_buffer (&scan_in);
	      break;
	    }
	  if (token == CPP_NAME && length == 7
	      && strcmp ("_filbuf", scan_in.token_buffer + old_written) == 0)
	    seen_filbuf++;
	}
      if (seen_filbuf)
	{
	  int need_filbuf = !SEEN (fn) && !REQUIRED (fn);
	  struct fn_decl *flsbuf_fn = lookup_std_proto ("_flsbuf", 7);
	  int need_flsbuf
	    = flsbuf_fn && !SEEN (flsbuf_fn) && !REQUIRED (flsbuf_fn);

	  /* Append "_filbuf" and/or "_flsbuf" to end of
	     required_functions_list. */
	  if (need_filbuf + need_flsbuf)
	    {
	      int old_len = namelist_end (required_functions_list)
		- required_functions_list;
	      char *new_list = (char*) xmalloc (old_len + 20);
	      bcopy (required_functions_list, new_list, old_len);
	      if (need_filbuf)
		{
		  strcpy (new_list + old_len, "_filbuf");
		  old_len += 8;
		  SET_REQUIRED (fn);
		}
	      if (need_flsbuf)
		{
		  strcpy (new_list + old_len, "_flsbuf");
		  old_len += 8;
		  SET_REQUIRED (flsbuf_fn);
		}
	      new_list[old_len] = '\0';
	      required_functions_list = (namelist)new_list;
	      required_unseen_count += need_filbuf + need_flsbuf;
	    }
	}
    }

  if (required_unseen_count + partial_count + missing_errno
#if ADD_MISSING_EXTERN_C
      + missing_extern_C_count
#endif      
      == 0)
    {
      if (verbose)
	fprintf (stderr, "%s: OK, nothing needs to be done.\n", inc_filename);
      exit (0);
    }
  if (!verbose)
    fprintf (stderr, "%s: fixing %s\n", progname, inc_filename);
  else
    {
      if (required_unseen_count)
	fprintf (stderr, "%s: %d missing function declarations.\n",
		 inc_filename, required_unseen_count);
      if (partial_count)
	fprintf (stderr, "%s: %d non-prototype function declarations.\n",
		 inc_filename, partial_count);
#if ADD_MISSING_EXTERN_C
      if (missing_extern_C_count)
	fprintf (stderr,
		 "%s: %d declarations not protected by extern \"C\".\n",
		 inc_filename, missing_extern_C_count);
#endif
    }
}

void
write_rbrac ()
{
  struct fn_decl *fn;
  const char *cptr;

  if (required_unseen_count)
    {
      fprintf (outf,
	"#if defined(__cplusplus) || defined(__USE_FIXED_PROTOTYPES__)\n");
#ifdef NO_IMPLICIT_EXTERN_C
      fprintf (outf, "#ifdef __cplusplus\nextern \"C\" {\n#endif\n");
#endif
    }

  /* Now we print out prototypes for those functions that we haven't seen. */
  for (cptr = required_functions_list; *cptr!= '\0'; )
    {
      int macro_protect = 0;
      int name_len = strlen (cptr);

      fn = lookup_std_proto (cptr, name_len);
      cptr+= name_len + 1;
      if (fn == NULL || !REQUIRED (fn))
	continue;

      /* In the case of memmove, protect in case the application
	 defines it as a macro before including the header.  */
      if (!strcmp (fn->fname, "memmove")
	  || !strcmp (fn->fname, "vprintf")
	  || !strcmp (fn->fname, "vfprintf")
	  || !strcmp (fn->fname, "vsprintf")
	  || !strcmp (fn->fname, "rewinddir"))
	macro_protect = 1;

      if (macro_protect)
	fprintf (outf, "#ifndef %s\n", fn->fname);
      fprintf (outf, "extern %s %s (%s);\n",
	       fn->rtype, fn->fname, fn->params);
      if (macro_protect)
	fprintf (outf, "#endif\n");
    }
  if (required_unseen_count)
    {
#ifdef NO_IMPLICIT_EXTERN_C
      fprintf (outf, "#ifdef __cplusplus\n}\n#endif\n");
#endif
      fprintf (outf,
	"#endif /* defined(__cplusplus) || defined(__USE_FIXED_PROTOTYPES__*/\n");
    }

  switch (special_file_handling)
    {
    case errno_h:
      if (missing_errno)
	fprintf (outf, "extern int errno;\n");
      break;
    case sys_stat_h:
      if (!seen_S_ISBLK && seen_S_IFBLK)
	fprintf (outf,
		 "#define S_ISBLK(mode) (((mode) & S_IFMT) == S_IFBLK)\n");
      if (!seen_S_ISCHR && seen_S_IFCHR)
	fprintf (outf,
		 "#define S_ISCHR(mode) (((mode) & S_IFMT) == S_IFCHR)\n");
      if (!seen_S_ISDIR && seen_S_IFDIR)
	fprintf (outf,
		 "#define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR)\n");
      if (!seen_S_ISFIFO && seen_S_IFIFO)
	fprintf (outf,
		 "#define S_ISFIFO(mode) (((mode) & S_IFMT) == S_IFIFO)\n");
      if (!seen_S_ISLNK && seen_S_IFLNK)
	fprintf (outf,
		 "#define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)\n");
      if (!seen_S_ISREG && seen_S_IFREG)
	fprintf (outf,
		 "#define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG)\n");
      break;
    }


#if ADD_MISSING_EXTERN_C
  if (missing_extern_C_count + required_unseen_count > 0)
    fprintf (outf, "#ifdef __cplusplus\n}\n#endif\n");
#endif
}

char *
xstrdup (str)
     char *str;
{
  char *copy = (char *) xmalloc (strlen (str) + 1);
  strcpy (copy, str);
  return copy;
}

/* Returns 1 iff the file is properly protected from multiple inclusion:
   #ifndef PROTECT_NAME
   #define PROTECT_NAME
   #endif

 */

#define INF_GET() (inf_ptr < inf_limit ? *(unsigned char*)inf_ptr++ : EOF)
#define INF_UNGET(c) ((c)!=EOF && inf_ptr--)

int
inf_skip_spaces (c)
     int c;
{
  for (;;)
    {
      if (c == ' ' || c == '\t')
	c = INF_GET ();
      else if (c == '/')
	{
	  c = INF_GET ();
	  if (c != '*')
	    {
	      INF_UNGET (c);
	      return '/';
	    }
	  c = INF_GET ();
	  for (;;)
	    {
	      if (c == EOF)
		return EOF;
	      else if (c != '*')
		{
		  if (c == '\n')
		    source_lineno++, lineno++;
		  c = INF_GET ();
		}
	      else if ((c = INF_GET ()) == '/')
		return INF_GET ();
	    }
	}
      else
	break;
    }
  return c;
}

/* Read into STR from inf_buffer upto DELIM. */

int
inf_read_upto (str, delim)
     sstring *str;
     int delim;
{
  int ch;
  for (;;)
    {
      ch = INF_GET ();
      if (ch == EOF || ch == delim)
	break;
      SSTRING_PUT (str, ch);
    }
  MAKE_SSTRING_SPACE (str, 1);
  *str->ptr = 0;
  return ch;
}

int
inf_scan_ident (s, c)
     register sstring *s;
     int c;
{
  s->ptr = s->base;