gcc.c

这是完整的gcc源代码

int
do_spec (spec)
     char *spec;
{
  int value;

  clear_args ();
  arg_going = 0;
  delete_this_arg = 0;
  this_is_output_file = 0;
  this_is_library_file = 0;

  value = do_spec_1 (spec, 0);

  /* Force out any unfinished command.
     If -pipe, this forces out the last command if it ended in `|'.  */
  if (value == 0)
    {
      if (argbuf_index > 0 && !strcmp (argbuf[argbuf_index - 1], "|"))
	argbuf_index--;

      if (argbuf_index > 0)
	value = execute ();
    }

  return value;
}

/* Process the sub-spec SPEC as a portion of a larger spec.
   This is like processing a whole spec except that we do
   not initialize at the beginning and we do not supply a
   newline by default at the end.
   INSWITCH nonzero means don't process %-sequences in SPEC;
   in this case, % is treated as an ordinary character.
   This is used while substituting switches.
   INSWITCH nonzero also causes SPC not to terminate an argument.

   Value is zero unless a line was finished
   and the command on that line reported an error.  */

int
do_spec_1 (spec, inswitch)
     char *spec;
     int inswitch;
{
  register char *p = spec;
  register int c;
  char *string;

  while (c = *p++)
    /* If substituting a switch, treat all chars like letters.
       Otherwise, NL, SPC, TAB and % are special.  */
    switch (inswitch ? 'a' : c)
      {
      case '\n':
	/* End of line: finish any pending argument,
	   then run the pending command if one has been started.  */
	if (arg_going)
	  {
	    obstack_1grow (&obstack, 0);
	    string = obstack_finish (&obstack);
	    if (this_is_library_file)
	      string = find_file (string);
	    store_arg (string, delete_this_arg, this_is_output_file);
	    if (this_is_output_file)
	      outfiles[input_file_number] = string;
	  }
	arg_going = 0;

	if (argbuf_index > 0 && !strcmp (argbuf[argbuf_index - 1], "|"))
	  {
	    int i;
	    for (i = 0; i < n_switches; i++)
	      if (!strcmp (switches[i].part1, "pipe"))
		break;

	    /* A `|' before the newline means use a pipe here,
	       but only if -pipe was specified.
	       Otherwise, execute now and don't pass the `|' as an arg.  */
	    if (i < n_switches)
	      {
		switches[i].valid = 1;
		break;
	      }
	    else
	      argbuf_index--;
	  }

	if (argbuf_index > 0)
	  {
	    int value = execute ();
	    if (value)
	      return value;
	  }
	/* Reinitialize for a new command, and for a new argument.  */
	clear_args ();
	arg_going = 0;
	delete_this_arg = 0;
	this_is_output_file = 0;
	this_is_library_file = 0;
	break;

      case '|':
	/* End any pending argument.  */
	if (arg_going)
	  {
	    obstack_1grow (&obstack, 0);
	    string = obstack_finish (&obstack);
	    if (this_is_library_file)
	      string = find_file (string);
	    store_arg (string, delete_this_arg, this_is_output_file);
	    if (this_is_output_file)
	      outfiles[input_file_number] = string;
	  }

	/* Use pipe */
	obstack_1grow (&obstack, c);
	arg_going = 1;
	break;

      case '\t':
      case ' ':
	/* Space or tab ends an argument if one is pending.  */
	if (arg_going)
	  {
	    obstack_1grow (&obstack, 0);
	    string = obstack_finish (&obstack);
	    if (this_is_library_file)
	      string = find_file (string);
	    store_arg (string, delete_this_arg, this_is_output_file);
	    if (this_is_output_file)
	      outfiles[input_file_number] = string;
	  }
	/* Reinitialize for a new argument.  */
	arg_going = 0;
	delete_this_arg = 0;
	this_is_output_file = 0;
	this_is_library_file = 0;
	break;

      case '%':
	switch (c = *p++)
	  {
	  case 0:
	    fatal ("Invalid specification!  Bug in cc.");

	  case 'b':
	    obstack_grow (&obstack, input_basename, basename_length);
	    arg_going = 1;
	    break;

	  case 'd':
	    delete_this_arg = 2;
	    break;

	  case 'e':
	    /* {...:%efoo} means report an error with `foo' as error message
	       and don't execute any more commands for this file.  */
	    {
	      char *q = p;
	      char *buf;
	      while (*p != 0 && *p != '\n') p++;
	      buf = (char *) alloca (p - q + 1);
	      strncpy (buf, q, p - q);
	      buf[p - q] = 0;
	      error ("%s", buf);
	      return -1;
	    }
	    break;

	  case 'g':
	    obstack_grow (&obstack, temp_filename, temp_filename_length);
	    delete_this_arg = 1;
	    arg_going = 1;
	    break;

	  case 'i':
	    obstack_grow (&obstack, input_filename, input_filename_length);
	    arg_going = 1;
	    break;

	  case 'o':
	    {
	      register int f;
	      for (f = 0; f < n_infiles; f++)
		store_arg (outfiles[f], 0, 0);
	    }
	    break;

	  case 's':
	    this_is_library_file = 1;
	    break;

	  case 'W':
	    {
	      int index = argbuf_index;
	      /* Handle the {...} following the %W.  */
	      if (*p != '{')
		abort ();
	      p = handle_braces (p + 1);
	      if (p == 0)
		return -1;
	      /* If any args were output, mark the last one for deletion
		 on failure.  */
	      if (argbuf_index != index)
		record_temp_file (argbuf[argbuf_index - 1], 0, 1);
	      break;
	    }

	  case 'w':
	    this_is_output_file = 1;
	    break;

	  case '{':
	    p = handle_braces (p);
	    if (p == 0)
	      return -1;
	    break;

	  case '%':
	    obstack_1grow (&obstack, '%');
	    break;

/*** The rest just process a certain constant string as a spec.  */

	  case '1':
	    do_spec_1 (CC1_SPEC, 0);
	    break;

	  case 'a':
	    do_spec_1 (ASM_SPEC, 0);
	    break;

	  case 'c':
	    do_spec_1 (SIGNED_CHAR_SPEC, 0);
	    break;

	  case 'C':
	    do_spec_1 (CPP_SPEC, 0);
	    break;

	  case 'l':
	    do_spec_1 (LINK_SPEC, 0);
	    break;

	  case 'L':
	    do_spec_1 (LIB_SPEC, 0);
	    break;

	  case 'G':
	    do_spec_1 (LIBG_SPEC, 0);
	    break;

	  case 'p':
	    do_spec_1 (CPP_PREDEFINES, 0);
	    break;

	  case 'P':
	    {
	      char *x = (char *) alloca (strlen (CPP_PREDEFINES) * 2 + 1);
	      char *buf = x;
	      char *y = CPP_PREDEFINES;

	      /* Copy all of CPP_PREDEFINES into BUF,
		 but put __ after every -D and at the end of each arg,  */
	      while (1)
		{
		  if (! strncmp (y, "-D", 2))
		    {
		      *x++ = '-';
		      *x++ = 'D';
		      *x++ = '_';
		      *x++ = '_';
		      y += 2;
		    }
		  else if (*y == ' ' || *y == 0)
		    {
		      *x++ = '_';
		      *x++ = '_';
		      if (*y == 0)
			break;
		      else
			*x++ = *y++;
		    }
		  else
		    *x++ = *y++;
		}
	      *x = 0;

	      do_spec_1 (buf, 0);
	    }
	    break;

	  case 'S':
	    do_spec_1 (STARTFILE_SPEC, 0);
	    break;

	  case 'E':
	    do_spec_1 (ENDFILE_SPEC, 0);
	    break;

	  default:
	    abort ();
	  }
	break;

      default:
	/* Ordinary character: put it into the current argument.  */
	obstack_1grow (&obstack, c);
	arg_going = 1;
      }

  return 0;		/* End of string */
}

/* Return 0 if we call do_spec_1 and that returns -1.  */

char *
handle_braces (p)
     register char *p;
{
  register char *q;
  char *filter;
  int pipe = 0;
  int negate = 0;

  if (*p == '|')
    /* A `|' after the open-brace means,
       if the test fails, output a single minus sign rather than nothing.
       This is used in %{|!pipe:...}.  */
    pipe = 1, ++p;

  if (*p == '!')
    /* A `!' after the open-brace negates the condition:
       succeed if the specified switch is not present.  */
    negate = 1, ++p;

  filter = p;
  while (*p != ':' && *p != '}') p++;
  if (*p != '}')
    {
      register int count = 1;
      q = p + 1;
      while (count > 0)
	{
	  if (*q == '{')
	    count++;
	  else if (*q == '}')
	    count--;
	  else if (*q == 0)
	    abort ();
	  q++;
	}
    }
  else
    q = p + 1;

  if (p[-1] == '*' && p[0] == '}')
    {
      /* Substitute all matching switches as separate args.  */
      register int i;
      --p;
      for (i = 0; i < n_switches; i++)
	if (!strncmp (switches[i].part1, filter, p - filter))
	  give_switch (i);
    }
  else
    {
      /* Test for presence of the specified switch.  */
      register int i;
      int present = 0;

      /* If name specified ends in *, as in {x*:...},
	 check for presence of any switch name starting with x.  */
      if (p[-1] == '*')
	{
	  for (i = 0; i < n_switches; i++)
	    {
	      if (!strncmp (switches[i].part1, filter, p - filter - 1))
		{
		  switches[i].valid = 1;
		  present = 1;
		}
	    }
	}
      /* Otherwise, check for presence of exact name specified.  */
      else
	{
	  for (i = 0; i < n_switches; i++)
	    {
	      if (!strncmp (switches[i].part1, filter, p - filter)
		  && switches[i].part1[p - filter] == 0)
		{
		  switches[i].valid = 1;
		  present = 1;
		  break;
		}
	    }
	}

      /* If it is as desired (present for %{s...}, absent for %{-s...})
	 then substitute either the switch or the specified
	 conditional text.  */
      if (present != negate)
	{
	  if (*p == '}')
	    {
	      give_switch (i);
	    }
	  else
	    {
	      if (do_spec_1 (save_string (p + 1, q - p - 2), 0) < 0)
		return 0;
	    }
	}
      else if (pipe)
	{
	  /* Here if a %{|...} conditional fails: output a minus sign,
	     which means "standard output" or "standard input".  */
	  do_spec_1 ("-", 0);
	}
    }

  return q;
}

/* Pass a switch to the current accumulating command
   in the same form that we received it.
   SWITCHNUM identifies the switch; it is an index into
   the vector of switches gcc received, which is `switches'.
   This cannot fail since it never finishes a command line.  */

give_switch (switchnum)
     int switchnum;
{
  do_spec_1 ("-", 0);
  do_spec_1 (switches[switchnum].part1, 1);
  do_spec_1 (" ", 0);
  if (switches[switchnum].part2 != 0)
    {
      do_spec_1 (switches[switchnum].part2, 1);
      do_spec_1 (" ", 0);
    }
  switches[switchnum].valid = 1;
}

/* Search for a file named NAME trying various prefixes including the
   user's -B prefix and some standard ones.
   Return the absolute pathname found.  If nothing is found, return NAME.  */

char *
find_file (name)
     char *name;
{
  int size;
  char *temp;
  int win = 0;

  /* Compute maximum size of NAME plus any prefix we will try.  */

  size = strlen (standard_exec_prefix);
  if (user_exec_prefix != 0 && strlen (user_exec_prefix) > size)
    size = strlen (user_exec_prefix);
  if (env_exec_prefix != 0 && strlen (env_exec_prefix) > size)
    size = strlen (env_exec_prefix);
  if (strlen (standard_exec_prefix) > size)
    size = strlen (standard_exec_prefix);
  if (strlen (standard_exec_prefix_1) > size)
    size = strlen (standard_exec_prefix_1);
  if (strlen (standard_startfile_prefix) > size)
    size = strlen (standard_startfile_prefix);
  if (strlen (standard_startfile_prefix_1) > size)
    size = strlen (standard_startfile_prefix_1);
  if (strlen (standard_startfile_prefix_2) > size)
    size = strlen (standard_startfile_prefix_2);
  if (machine_suffix)
    size += strlen (machine_suffix) + 1;
  size += strlen (name) + 1;

  temp = (char *) alloca (size);

  if (user_exec_prefix)
    {
      if (machine_suffix)
	{
	  strcpy (temp, user_exec_prefix);
	  strcat (temp, machine_suffix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
      if (!win)
	{
	  strcpy (temp, user_exec_prefix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
    }

  if (!win && env_exec_prefix)
    {
      if (machine_suffix)
	{
	  strcpy (temp, env_exec_prefix);
	  strcat (temp, machine_suffix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
      if (!win)
	{
	  strcpy (temp, env_exec_prefix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
    }

  if (!win)
    {
      if (machine_suffix)
	{
	  strcpy (temp, standard_exec_prefix);
	  strcat (temp, machine_suffix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
      if (!win)
	{
	  strcpy (temp, standard_exec_prefix);
	  strcat (temp, name);
	  win = (access (temp, R_OK) == 0);
	}
    }

  if (!win)
    {