cccp.c

gcc库的原代码,对编程有很大帮助.

	    int j;
	    inhibit_predefs = 1;
	    for (j = 0; j < i; j++)
	      pend_defs[j] = pend_assertions[j] = 0;
	  } else {
	    pend_assertions[i] = p;
	    pend_assertion_options[i] = "-A";
	  }
	}
	break;

      case 'U':		/* JF #undef something */
	if (argv[i][2] != 0)
	  pend_undefs[i] = argv[i] + 2;
	else if (i + 1 == argc)
	  fatal ("Macro name missing after -U option");
	else
	  pend_undefs[i] = argv[i+1], i++;
	break;

      case 'C':
	put_out_comments = 1;
	break;

      case 'E':			/* -E comes from cc -E; ignore it.  */
	break;

      case 'P':
	no_line_directives = 1;
	break;

      case '$':			/* Don't include $ in identifiers.  */
	dollars_in_ident = 0;
	break;

      case 'I':			/* Add directory to path for includes.  */
	{
	  struct file_name_list *dirtmp;

	  if (! ignore_srcdir && !strcmp (argv[i] + 2, "-")) {
	    ignore_srcdir = 1;
	    /* Don't use any preceding -I directories for #include <...>.  */
	    first_bracket_include = 0;
	  }
	  else {
	    dirtmp = (struct file_name_list *)
	      xmalloc (sizeof (struct file_name_list));
	    dirtmp->next = 0;		/* New one goes on the end */
	    dirtmp->control_macro = 0;
	    dirtmp->c_system_include_path = 0;
	    if (argv[i][2] != 0)
	      dirtmp->fname = argv[i] + 2;
	    else if (i + 1 == argc)
	      fatal ("Directory name missing after -I option");
	    else
	      dirtmp->fname = argv[++i];
	    dirtmp->got_name_map = 0;
	    append_include_chain (dirtmp, dirtmp);
	  }
	}
	break;

      case 'n':
	if (!strcmp (argv[i], "-nostdinc"))
	  /* -nostdinc causes no default include directories.
	     You must specify all include-file directories with -I.  */
	  no_standard_includes = 1;
	else if (!strcmp (argv[i], "-nostdinc++"))
	  /* -nostdinc++ causes no default C++-specific include directories. */
	  no_standard_cplusplus_includes = 1;
	else if (!strcmp (argv[i], "-noprecomp"))
	  no_precomp = 1;
	break;

      case 'u':
	/* Sun compiler passes undocumented switch "-undef".
	   Let's assume it means to inhibit the predefined symbols.  */
	inhibit_predefs = 1;
	break;

      case '\0': /* JF handle '-' as file name meaning stdin or stdout */
	if (in_fname == NULL) {
	  in_fname = "";
	  break;
	} else if (out_fname == NULL) {
	  out_fname = "";
	  break;
	}	/* else fall through into error */

      default:
	fatal ("Invalid option `%s'", argv[i]);
      }
    }
  }

  /* Add dirs from CPATH after dirs from -I.  */
  /* There seems to be confusion about what CPATH should do,
     so for the moment it is not documented.  */
  /* Some people say that CPATH should replace the standard include dirs,
     but that seems pointless: it comes before them, so it overrides them
     anyway.  */
  cp = getenv ("CPATH");
  if (cp && ! no_standard_includes)
    path_include (cp);

  /* Now that dollars_in_ident is known, initialize is_idchar.  */
  initialize_char_syntax ();

  /* Initialize output buffer */

  outbuf.buf = (U_CHAR *) xmalloc (OUTBUF_SIZE);
  outbuf.bufp = outbuf.buf;
  outbuf.length = OUTBUF_SIZE;

  /* Do partial setup of input buffer for the sake of generating
     early #line directives (when -g is in effect).  */

  fp = &instack[++indepth];
  if (in_fname == NULL)
    in_fname = "";
  fp->nominal_fname = fp->fname = in_fname;
  fp->lineno = 0;

  /* In C++, wchar_t is a distinct basic type, and we can expect
     __wchar_t to be defined by cc1plus.  */
  if (cplusplus)
    wchar_type = "__wchar_t";

  /* Install __LINE__, etc.  Must follow initialize_char_syntax
     and option processing.  */
  initialize_builtins (fp, &outbuf);

  /* Do standard #defines and assertions
     that identify system and machine type.  */

  if (!inhibit_predefs) {
    char *p = (char *) alloca (strlen (predefs) + 1);
    strcpy (p, predefs);
    while (*p) {
      char *q;
      while (*p == ' ' || *p == '\t')
	p++;
      /* Handle -D options.  */ 
      if (p[0] == '-' && p[1] == 'D') {
	q = &p[2];
	while (*p && *p != ' ' && *p != '\t')
	  p++;
	if (*p != 0)
	  *p++= 0;
	if (debug_output)
	  output_line_directive (fp, &outbuf, 0, same_file);
	make_definition (q, &outbuf);
	while (*p == ' ' || *p == '\t')
	  p++;
      } else if (p[0] == '-' && p[1] == 'A') {
	/* Handle -A options (assertions).  */ 
	char *assertion;
	char *past_name;
	char *value;
	char *past_value;
	char *termination;
	int save_char;

	assertion = &p[2];
	past_name = assertion;
	/* Locate end of name.  */
	while (*past_name && *past_name != ' '
	       && *past_name != '\t' && *past_name != '(')
	  past_name++;
	/* Locate `(' at start of value.  */
	value = past_name;
	while (*value && (*value == ' ' || *value == '\t'))
	  value++;
	if (*value++ != '(')
	  abort ();
	while (*value && (*value == ' ' || *value == '\t'))
	  value++;
	past_value = value;
	/* Locate end of value.  */
	while (*past_value && *past_value != ' '
	       && *past_value != '\t' && *past_value != ')')
	  past_value++;
	termination = past_value;
	while (*termination && (*termination == ' ' || *termination == '\t'))
	  termination++;
	if (*termination++ != ')')
	  abort ();
	if (*termination && *termination != ' ' && *termination != '\t')
	  abort ();
	/* Temporarily null-terminate the value.  */
	save_char = *termination;
	*termination = '\0';
	/* Install the assertion.  */
	make_assertion ("-A", assertion);
	*termination = (char) save_char;
	p = termination;
	while (*p == ' ' || *p == '\t')
	  p++;
      } else {
	abort ();
      }
    }
  }

  /* Now handle the command line options.  */

  /* Do -U's, -D's and -A's in the order they were seen.  */
  for (i = 1; i < argc; i++) {
    if (pend_undefs[i]) {
      if (debug_output)
        output_line_directive (fp, &outbuf, 0, same_file);
      make_undef (pend_undefs[i], &outbuf);
    }
    if (pend_defs[i]) {
      if (debug_output)
        output_line_directive (fp, &outbuf, 0, same_file);
      make_definition (pend_defs[i], &outbuf);
    }
    if (pend_assertions[i])
      make_assertion (pend_assertion_options[i], pend_assertions[i]);
  }

  done_initializing = 1;

  { /* read the appropriate environment variable and if it exists
       replace include_defaults with the listed path. */
    char *epath = 0;
    switch ((objc << 1) + cplusplus)
      {
      case 0:
	epath = getenv ("C_INCLUDE_PATH");
	break;
      case 1:
	epath = getenv ("CPLUS_INCLUDE_PATH");
	break;
      case 2:
	epath = getenv ("OBJC_INCLUDE_PATH");
	break;
      case 3:
	epath = getenv ("OBJCPLUS_INCLUDE_PATH");
	break;
      }
    /* If the environment var for this language is set,
       add to the default list of include directories.  */
    if (epath) {
      char *nstore = (char *) alloca (strlen (epath) + 2);
      int num_dirs;
      char *startp, *endp;

      for (num_dirs = 1, startp = epath; *startp; startp++)
	if (*startp == PATH_SEPARATOR)
	  num_dirs++;
      include_defaults
	= (struct default_include *) xmalloc ((num_dirs
					       * sizeof (struct default_include))
					      + sizeof (include_defaults_array));
      startp = endp = epath;
      num_dirs = 0;
      while (1) {
        /* Handle cases like c:/usr/lib:d:/gcc/lib */
        if ((*endp == PATH_SEPARATOR
#if 0 /* Obsolete, now that we use semicolons as the path separator.  */
#ifdef __MSDOS__
	     && (endp-startp != 1 || !isalpha (*startp))
#endif
#endif
	     )
            || *endp == 0) {
	  strncpy (nstore, startp, endp-startp);
	  if (endp == startp)
	    strcpy (nstore, ".");
	  else
	    nstore[endp-startp] = '\0';

	  include_defaults[num_dirs].fname = savestring (nstore);
	  include_defaults[num_dirs].cplusplus = cplusplus;
	  include_defaults[num_dirs].cxx_aware = 1;
	  num_dirs++;
	  if (*endp == '\0')
	    break;
	  endp = startp = endp + 1;
	} else
	  endp++;
      }
      /* Put the usual defaults back in at the end.  */
      bcopy ((char *) include_defaults_array,
	     (char *) &include_defaults[num_dirs],
	     sizeof (include_defaults_array));
    }
  }

  append_include_chain (before_system, last_before_system);
  first_system_include = before_system;

  /* Unless -fnostdinc,
     tack on the standard include file dirs to the specified list */
  if (!no_standard_includes) {
    struct default_include *p = include_defaults;
    char *specd_prefix = include_prefix;
    char *default_prefix = savestring (GCC_INCLUDE_DIR);
    int default_len = 0;
    /* Remove the `include' from /usr/local/lib/gcc.../include.  */
    if (!strcmp (default_prefix + strlen (default_prefix) - 8, "/include")) {
      default_len = strlen (default_prefix) - 7;
      default_prefix[default_len] = 0;
    }
    /* Search "translated" versions of GNU directories.
       These have /usr/local/lib/gcc... replaced by specd_prefix.  */
    if (specd_prefix != 0 && default_len != 0)
      for (p = include_defaults; p->fname; p++) {
	/* Some standard dirs are only for C++.  */
	if (!p->cplusplus || (cplusplus && !no_standard_cplusplus_includes)) {
	  /* Does this dir start with the prefix?  */
	  if (!strncmp (p->fname, default_prefix, default_len)) {
	    /* Yes; change prefix and add to search list.  */
	    struct file_name_list *new
	      = (struct file_name_list *) xmalloc (sizeof (struct file_name_list));
	    int this_len = strlen (specd_prefix) + strlen (p->fname) - default_len;
	    char *str = xmalloc (this_len + 1);
	    strcpy (str, specd_prefix);
	    strcat (str, p->fname + default_len);
	    new->fname = str;
	    new->control_macro = 0;
	    new->c_system_include_path = !p->cxx_aware;
	    new->got_name_map = 0;
	    append_include_chain (new, new);
	    if (first_system_include == 0)
	      first_system_include = new;
	  }
	}
      }
    /* Search ordinary names for GNU include directories.  */
    for (p = include_defaults; p->fname; p++) {
      /* Some standard dirs are only for C++.  */
      if (!p->cplusplus || (cplusplus && !no_standard_cplusplus_includes)) {
	struct file_name_list *new
	  = (struct file_name_list *) xmalloc (sizeof (struct file_name_list));
	new->control_macro = 0;
	new->c_system_include_path = !p->cxx_aware;
	new->fname = p->fname;
	new->got_name_map = 0;
	append_include_chain (new, new);
	if (first_system_include == 0)
	  first_system_include = new;
      }
    }
  }

  /* Tack the after_include chain at the end of the include chain.  */
  append_include_chain (after_include, last_after_include);
  if (first_system_include == 0)
    first_system_include = after_include;

  /* With -v, print the list of dirs to search.  */
  if (verbose) {
    struct file_name_list *p;
    fprintf (stderr, "#include \"...\" search starts here:\n");
    for (p = include; p; p = p->next) {
      if (p == first_bracket_include)
	fprintf (stderr, "#include <...> search starts here:\n");
      fprintf (stderr, " %s\n", p->fname);
    }
    fprintf (stderr, "End of search list.\n");
  }

  /* Scan the -imacros files before the main input.
     Much like #including them, but with no_output set
     so that only their macro definitions matter.  */

  no_output++; no_record_file++;
  for (i = 1; i < argc; i++)
    if (pend_files[i]) {
      int fd = open (pend_files[i], O_RDONLY, 0666);
      if (fd < 0) {
	perror_with_name (pend_files[i]);
	return FATAL_EXIT_CODE;
      }
      finclude (fd, pend_files[i], &outbuf, 0, NULL_PTR);
    }
  no_output--; no_record_file--;

  /* Copy the entire contents of the main input file into
     the stacked input buffer previously allocated for it.  */

  /* JF check for stdin */
  if (in_fname == NULL || *in_fname == 0) {
    in_fname = "";
    f = 0;
  } else if ((f = open (in_fname, O_RDONLY, 0666)) < 0)
    goto perror;

  /* -MG doesn't select the form of output and must be specified with one of
     -M or -MM.  -MG doesn't make sense with -MD or -MMD since they don't
     inhibit compilation.  */
  if (print_deps_missing_files && (print_deps == 0 || !inhibit_output))
    fatal ("-MG must be specified with one of -M or -MM");

  /* Either of two environment variables can specify output of deps.
     Its value is either "OUTPUT_FILE" or "OUTPUT_FILE DEPS_TARGET",
     where OUTPUT_FILE is the file to write deps info to
     and DEPS_TARGET is the target to mention in the deps.  */

  if (print_deps == 0
      && (getenv ("SUNPRO_DEPENDENCIES") != 0
	  || getenv ("DEPENDENCIES_OUTPUT") != 0)) {
    char *spec = getenv ("DEPENDENCIES_OUTPUT");
    char *s;
    char *output_file;

    if (spec == 0) {
      spec = getenv ("SUNPRO_DEPENDENCIES");
      print_deps = 2;
    }
    else
      print_deps = 1;

    s = spec;
    /* Find the space before the DEPS_TARGET, if there is one.  */
    /* This should use index.  (mrs) */
    while (*s != 0 && *s != ' ') s++;
    if (*s != 0) {
      deps_target = s + 1;
      output_file = xmalloc (s - spec + 1);
      bcopy (spec, output_file, s - spec);
      output_file[s - spec] = 0;
    }
    else {
      deps_target = 0;
      output_file