sta.c

gcc-2.95.3 Linux下最常用的C编译器

  ffesta_possible_execs_.nil = ffesta_possible_nonexecs_.nil = NULL;
}

/* ffesta_init_3 -- Initialize for any program unit

   ffesta_init_3();  */

void
ffesta_init_3 ()
{
  ffesta_output_pool = NULL;	/* May be doing this just before reaching */
  ffesta_scratch_pool = NULL;	/* ffesta_zero or ffesta_two. */
  /* NOTE: we let the ffe_terminate_2 action of killing the program_unit pool
     handle the killing of the output and scratch pools for us, which is why
     we don't have a terminate_3 action to do so. */
  ffesta_construct_name = NULL;
  ffesta_label_token = NULL;
  ffesta_seen_first_exec = FALSE;
}

/* ffesta_is_inhibited -- Test whether the current possibility is inhibited

   if (!ffesta_is_inhibited())
       // implement the statement.

   Just make sure the current possibility has been confirmed.  If anyone
   really needs to test whether the current possibility is inhibited prior
   to confirming it, that indicates a need to begin statement processing
   before it is certain that the given possibility is indeed the statement
   to be processed.  As of this writing, there does not appear to be such
   a need.  If there is, then when confirming a statement would normally
   immediately disable the inhibition (whereas currently we leave the
   confirmed statement disabled until we've tried the other possibilities,
   to check for ambiguities), we must check to see if the possibility has
   already tested for inhibition prior to confirmation and, if so, maintain
   inhibition until the end of the statement (which may be forced right
   away) and then rerun the entire statement from the beginning.  Otherwise,
   initial calls to ffestb functions won't have been made, but subsequent
   calls (after confirmation) will, which is wrong.  Of course, this all
   applies only to those statements implemented via multiple calls to
   ffestb, although if a statement requiring only a single ffestb call
   tested for inhibition prior to confirmation, it would likely mean that
   the ffestb call would be completely dropped without this mechanism.	*/

bool
ffesta_is_inhibited ()
{
  assert (ffesta_confirmed_current_ || ffesta_inhibit_confirmation_);
  return ffesta_is_inhibited_;
}

/* ffesta_ffebad_1p -- Issue diagnostic with one source character

   ffelexToken names_token;
   ffeTokenLength index;
   ffelexToken next_token;
   ffesta_ffebad_1p(FFEBAD_SOME_ERROR,names_token,index,next_token);

   Equivalent to "if (ffest_ffebad_start(FFEBAD_SOME_ERROR))" followed by
   sending one argument, the location of index with names_token, if TRUE is
   returned.  If index is equal to the length of names_token, meaning it
   points to the end of the token, then uses the location in next_token
   (which should be the token sent by the lexer after it sent names_token)
   instead.  */

void
ffesta_ffebad_1p (ffebad errnum, ffelexToken names_token, ffeTokenLength index,
		  ffelexToken next_token)
{
  ffewhereLine line;
  ffewhereColumn col;

  assert (index <= ffelex_token_length (names_token));

  if (ffesta_ffebad_start (errnum))
    {
      if (index == ffelex_token_length (names_token))
	{
	  assert (next_token != NULL);
	  line = ffelex_token_where_line (next_token);
	  col = ffelex_token_where_column (next_token);
	  ffebad_here (0, line, col);
	}
      else
	{
	  ffewhere_set_from_track (&line, &col,
				   ffelex_token_where_line (names_token),
				   ffelex_token_where_column (names_token),
				   ffelex_token_wheretrack (names_token),
				   index);
	  ffebad_here (0, line, col);
	  ffewhere_line_kill (line);
	  ffewhere_column_kill (col);
	}
      ffebad_finish ();
    }
}

void
ffesta_ffebad_1sp (ffebad errnum, const char *s, ffelexToken names_token,
		   ffeTokenLength index, ffelexToken next_token)
{
  ffewhereLine line;
  ffewhereColumn col;

  assert (index <= ffelex_token_length (names_token));

  if (ffesta_ffebad_start (errnum))
    {
      ffebad_string (s);
      if (index == ffelex_token_length (names_token))
	{
	  assert (next_token != NULL);
	  line = ffelex_token_where_line (next_token);
	  col = ffelex_token_where_column (next_token);
	  ffebad_here (0, line, col);
	}
      else
	{
	  ffewhere_set_from_track (&line, &col,
				   ffelex_token_where_line (names_token),
				   ffelex_token_where_column (names_token),
				   ffelex_token_wheretrack (names_token),
				   index);
	  ffebad_here (0, line, col);
	  ffewhere_line_kill (line);
	  ffewhere_column_kill (col);
	}
      ffebad_finish ();
    }
}

void
ffesta_ffebad_1st (ffebad errnum, const char *s, ffelexToken t)
{
  if (ffesta_ffebad_start (errnum))
    {
      ffebad_string (s);
      ffebad_here (0, ffelex_token_where_line (t), ffelex_token_where_column (t));
      ffebad_finish ();
    }
}

/* ffesta_ffebad_1t -- Issue diagnostic with one source token

   ffelexToken t;
   ffesta_ffebad_1t(FFEBAD_SOME_ERROR,t);

   Equivalent to "if (ffesta_ffebad_start(FFEBAD_SOME_ERROR))" followed by
   sending one argument, the location of the token t, if TRUE is returned.  */

void
ffesta_ffebad_1t (ffebad errnum, ffelexToken t)
{
  if (ffesta_ffebad_start (errnum))
    {
      ffebad_here (0, ffelex_token_where_line (t), ffelex_token_where_column (t));
      ffebad_finish ();
    }
}

void
ffesta_ffebad_2st (ffebad errnum, const char *s, ffelexToken t1, ffelexToken t2)
{
  if (ffesta_ffebad_start (errnum))
    {
      ffebad_string (s);
      ffebad_here (0, ffelex_token_where_line (t1), ffelex_token_where_column (t1));
      ffebad_here (1, ffelex_token_where_line (t2), ffelex_token_where_column (t2));
      ffebad_finish ();
    }
}

/* ffesta_ffebad_2t -- Issue diagnostic with two source tokens

   ffelexToken t1, t2;
   ffesta_ffebad_2t(FFEBAD_SOME_ERROR,t1,t2);

   Equivalent to "if (ffesta_ffebad_start(FFEBAD_SOME_ERROR))" followed by
   sending two argument, the locations of the tokens t1 and t2, if TRUE is
   returned.  */

void
ffesta_ffebad_2t (ffebad errnum, ffelexToken t1, ffelexToken t2)
{
  if (ffesta_ffebad_start (errnum))
    {
      ffebad_here (0, ffelex_token_where_line (t1), ffelex_token_where_column (t1));
      ffebad_here (1, ffelex_token_where_line (t2), ffelex_token_where_column (t2));
      ffebad_finish ();
    }
}

ffestaPooldisp
ffesta_outpooldisp ()
{
  return ffesta_outpooldisp_;
}

void
ffesta_set_outpooldisp (ffestaPooldisp d)
{
  ffesta_outpooldisp_ = d;
}

/* Shut down current parsing possibility, but without bothering the
   user with a diagnostic if we're not inhibited.  */

void
ffesta_shutdown ()
{
  if (ffesta_is_inhibited_)
    ffesta_current_shutdown_ = TRUE;
}

/* ffesta_two -- Deal with the first two tokens after a swallowed statement

   return ffesta_two(first_token,second_token);	 // to lexer.

   Like ffesta_zero, except instead of expecting an EOS or SEMICOLON, it
   expects the first two tokens of a statement that is part of another
   statement: the first two tokens of statement in "IF (expr) statement" or
   "WHERE (expr) statement", in particular.  The first token must be a NAME
   or NAMES, the second can be basically anything.  The statement type MUST
   be confirmed by now.

   If we're not inhibited, just handle things as if we were ffesta_zero
   and saw an EOS just before the two tokens.

   If we're inhibited, set ffesta_current_shutdown_ to shut down the current
   statement and continue with other possibilities, then (presumably) come
   back to this one for real when not inhibited.  */

ffelexHandler
ffesta_two (ffelexToken first, ffelexToken second)
{
#if FFESTA_ABORT_ON_CONFIRM_
  ffelexHandler next;
#endif

  assert ((ffelex_token_type (first) == FFELEX_typeNAME)
	  || (ffelex_token_type (first) == FFELEX_typeNAMES));
  assert (ffesta_tokens[0] != NULL);

  if (ffesta_is_inhibited_)	/* Oh, not really done with statement. */
    {
      ffesta_current_shutdown_ = TRUE;
      /* To catch the EOS on shutdown. */
      return (ffelexHandler) ffelex_swallow_tokens (second,
					       (ffelexHandler) ffesta_zero);
    }

  ffestw_display_state ();

  ffelex_token_kill (ffesta_tokens[0]);

  if (ffesta_output_pool != NULL)
    {
      if (ffesta_outpooldisp_ == FFESTA_pooldispDISCARD)
	malloc_pool_kill (ffesta_output_pool);
      ffesta_output_pool = NULL;
    }

  if (ffesta_scratch_pool != NULL)
    {
      malloc_pool_kill (ffesta_scratch_pool);
      ffesta_scratch_pool = NULL;
    }

  ffesta_reset_possibles_ ();
  ffesta_confirmed_current_ = FALSE;

  /* What happens here is somewhat interesting.	 We effectively derail the
     line of handlers for these two tokens, the first two in a statement, by
     setting a flag to TRUE.  This flag tells ffesta_save_ (or, conceivably,
     the lexer via ffesta_second_'s case 1:, where it has only one possible
     kind of statement -- someday this will be more likely, i.e. after
     confirmation causes an immediate switch to only the one context rather
     than just setting a flag and running through the remaining possibles to
     look for ambiguities) that the last two tokens it sent did not reach the
     truly desired targets (ffest_first and ffesta_second_) since that would
     otherwise attempt to recursively invoke ffesta_save_ in most cases,
     while the existing ffesta_save_ was still alive and making use of static
     (nonrecursive) variables.	Instead, ffesta_save_, upon seeing this flag
     set TRUE, sets it to FALSE and resubmits the two tokens copied here to
     ffest_first and, presumably, ffesta_second_, kills them, and returns the
     handler returned by the handler for the second token.  Thus, even though
     ffesta_save_ is still (likely to be) recursively invoked, the former
     invocation is past the use of any static variables possibly changed
     during the first-two-token invocation of the latter invocation. */

#if FFESTA_ABORT_ON_CONFIRM_
  /* Shouldn't be in ffesta_save_ at all here. */

  next = (ffelexHandler) ffesta_first (first);
  return (ffelexHandler) (*next) (second);
#else
  ffesta_twotokens_1_ = ffelex_token_use (first);
  ffesta_twotokens_2_ = ffelex_token_use (second);

  ffesta_is_two_into_statement_ = TRUE;
  return (ffelexHandler) ffesta_send_two_;	/* Shouldn't get called. */
#endif
}

/* ffesta_zero -- Deal with the end of a swallowed statement

   return ffesta_zero;	// to lexer.

   NOTICE that this code is COPIED, largely, into a
   similar function named ffesta_two that gets invoked in place of
   _zero_ when the end of the statement happens before EOS or SEMICOLON and
   to tokens into the next statement have been read (as is the case with the
   logical-IF and WHERE-stmt statements).  So any changes made here should
   probably be made in _two_ at the same time.	*/

ffelexHandler
ffesta_zero (ffelexToken t)
{
  assert ((ffelex_token_type (t) == FFELEX_typeEOS)
	  || (ffelex_token_type (t) == FFELEX_typeSEMICOLON));
  assert (ffesta_tokens[0] != NULL);

  if (ffesta_is_inhibited_)
    ffesymbol_retract (TRUE);
  else
    ffestw_display_state ();

  /* Do CONTINUE if nothing else.  This is done specifically so that "IF
     (...) BLAH" causes the same things to happen as if "IF (...) CONTINUE"
     was done, so that tracking of labels and such works.  (Try a small
     program like "DO 10 ...", "IF (...) BLAH", "10 CONTINUE", "END".)

     But it turns out that just testing "!ffesta_confirmed_current_"
     isn't enough, because then typing "GOTO" instead of "BLAH" above
     doesn't work -- the statement is confirmed (we know the user
     attempted a GOTO) but ffestc hasn't seen it.  So, instead, just
     always tell ffestc to do "any" statement it needs to reset.  */

  if (!ffesta_is_inhibited_
      && ffesta_seen_first_exec)
    {
      ffestc_any ();
    }

  ffelex_token_kill (ffesta_tokens[0]);

  if (ffesta_is_inhibited_)	/* Oh, not really done with statement. */
    return (ffelexHandler) ffesta_zero;	/* Call me again when done! */

  if (ffesta_output_pool != NULL)
    {
      if (ffesta_outpooldisp_ == FFESTA_pooldispDISCARD)
	malloc_pool_kill (ffesta_output_pool);
      ffesta_output_pool = NULL;
    }

  if (ffesta_scratch_pool != NULL)
    {
      malloc_pool_kill (ffesta_scratch_pool);
      ffesta_scratch_pool = NULL;
    }

  ffesta_reset_possibles_ ();
  ffesta_confirmed_current_ = FALSE;

  if (ffelex_token_type (t) == FFELEX_typeSEMICOLON)
    {
      ffesta_line_has_semicolons = TRUE;
      if (ffe_is_pedantic_not_90 ())
	{
	  ffebad_start (FFEBAD_SEMICOLON);
	  ffebad_here (0, ffelex_token_where_line (t), ffelex_token_where_column (t));
	  ffebad_finish ();
	}
    }
  else
    ffesta_line_has_semicolons = FALSE;

  if (ffesta_label_token != NULL)
    {
      ffelex_token_kill (ffesta_label_token);
      ffesta_label_token = NULL;
    }

  if (ffe_is_ffedebug ())
    {
      ffestorag_report ();
#if FFECOM_targetCURRENT == FFECOM_targetFFE
      ffesymbol_report_all ();
#endif
    }

  ffelex_set_names (TRUE);
  return (ffelexHandler) ffesta_first;
}