/* Copyright (c) 1992, Free Software Foundation, Inc.  All rights reserved.

   Copyright (c) 1985 Sun Microsystems, Inc. Copyright (c) 1980 The Regents
   of the University of California. Copyright (c) 1976 Board of Trustees of
   the University of Illinois. All rights reserved.

   Redistribution and use in source and binary forms are permitted
   provided that
   the above copyright notice and this paragraph are duplicated in all such
   forms and that any documentation, advertising materials, and other
   materials related to such distribution and use acknowledge that the
   software was developed by the University of California, Berkeley, the
   University of Illinois, Urbana, and Sun Microsystems, Inc.  The name of
   either University or Sun Microsystems may not be used to endorse or
   promote products derived from this software without specific prior written
   permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
   IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
   OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. */


/* NAME: pr_comment

FUNCTION: This routine takes care of scanning and printing comments.

ALGORITHM: 1) Decide where the comment should be aligned, and if lines should
   be broken. 2) If lines should not be broken and filled, just copy up to
   end of comment. 3) If lines should be filled, then scan thru input_buffer
   copying characters to com_buf.  Remember where the last blank, tab, or
   newline was.  When line is filled, print up to last blank and continue
   copying.

HISTORY: November 1976	D A Willcox of CAC	Initial coding 12/6/76
    A Willcox of CAC	Modification to handle UNIX-style comments

*/

/* this routine processes comments.  It makes an attempt to keep comments
   from going over the max line length.  If a line is too long, it moves
   everything from the last blank to the next comment line.  Blanks and tabs
   from the beginning of the input line are removed */


#include "sys.h"
#include "indent.h"

/* Declared and documented in indent.h.  */
int out_coms;

pr_comment ()
{
  int now_col;			/* column we are in now */
  int adj_max_col;		/* Adjusted max_col for when we decide to
				   spill comments over the right margin */
  char *last_bl;		/* points to the last blank in the output
				   buffer */
  char *t_ptr;			/* used for moving string */
  int unix_comment;		/* tri-state variable used to decide if it is
				   a unix-style comment. 0 means only blanks
				   since /*, 1 means regular style comment, 2
				   means unix style comment */
  int break_delim = comment_delimiter_on_blankline;
  int l_just_saw_decl = parser_state_tos->just_saw_decl;
  /* int         parser_state_tos->last_nl = 0;	/* true iff the last
     significant thing weve seen is a newline */
  int one_liner = 1;		/* true iff this comment is a one-liner */
  adj_max_col = max_col;
  parser_state_tos->just_saw_decl = 0;
  last_bl = 0;			/* no blanks found so far */
  parser_state_tos->box_com = false;	/* at first, assume that we are not
					   in a boxed comment or some other
					   comment that should not be touched */
  ++out_coms;			/* keep track of number of comments */
  unix_comment = 1;		/* set flag to let us figure out if there is
				   a unix-style comment ** DISABLED: use 0 to
				   reenable this hack! */

  /* Figure where to align and how to treat the comment */

  if (parser_state_tos->col_1 && !format_col1_comments)
    {				/* if comment starts in column 1 it should
				   not be touched */
      parser_state_tos->box_com = true;
      parser_state_tos->com_col = 1;
    }
  else
    {
      if (*buf_ptr == '-' || *buf_ptr == '*' || !format_comments)
	{
	  parser_state_tos->box_com = true;	/* a comment with a '-' or
						   '*' immediately after the
						   /* is assumed to be a
						   boxed comment */
	  break_delim = 0;
	}


      /* Used to also check that parser_state_tos->bl_line != 0 */
      if ((s_lab == e_lab) && (s_code == e_code))
	{
	  /* klg: check only if this line is blank */
	  /* If this (*and previous lines are*) blank, dont put comment way
	     out at left */
	  parser_state_tos->com_col
	    = (parser_state_tos->ind_level - unindent_displace) + 1;
	  adj_max_col = block_comment_max_col;
	  if (parser_state_tos->com_col <= 1)
	    parser_state_tos->com_col = 1 + !format_col1_comments;

	  /* If we have a comment in an old-style (pre-ANSI) parameter
	     declaration, indent it like we would the parameter declaration.
	     For example:
	       int destroy (what) / * N things to destroy.  * / int what;
	  */
	  if (parser_state_tos->in_parameter_declaration
	      && indent_parameters != 0
	      && parser_state_tos->dec_nest == 0)
	    {
	      parser_state_tos->com_col = indent_parameters + 1;
	      parser_state_tos->ind_stmt = 0;
	    }
	}
      else
	{
	  register target_col;
	  break_delim = 0;
	  if (s_code != e_code)
	    target_col = count_spaces (compute_code_target (), s_code);
	  else
	    {
	      target_col = 1;
	      if (s_lab != e_lab)
		target_col = count_spaces (compute_label_target (), s_lab);
	    }
	  parser_state_tos->com_col = parser_state_tos->decl_on_line
	    || parser_state_tos->ind_level == 0 ? decl_com_ind : com_ind;
	  /* If we are already past the position for the comment, put it at
	     the next tab stop.  */
	  if (parser_state_tos->com_col < target_col)
	    parser_state_tos->com_col = ((target_col + (tabsize - 1))
					 & ~(tabsize - 1)) + 1;
	  if (else_or_endif)
	    {
	      parser_state_tos->com_col = else_endif_col;
	      else_or_endif = false;
	      /* We want the comment to appear one space after the #else or
	         #endif.  */
	      if (parser_state_tos->com_col < target_col)
		parser_state_tos->com_col = target_col + 1;
	    }
	  if (parser_state_tos->com_col + 24 > adj_max_col)
	    adj_max_col = parser_state_tos->com_col + 24;
	}
    }
  if (parser_state_tos->box_com)
    {
      parser_state_tos->n_comment_delta = 1 - parser_state_tos->com_col;
#if 0
      buf_ptr[-2] = 0;
      parser_state_tos->n_comment_delta = 1 - count_spaces (1, cur_line);
      buf_ptr[-2] = '/';
#endif
    }
  else
    {
      parser_state_tos->n_comment_delta = 0;
      while (*buf_ptr == ' ' || *buf_ptr == '\t')
	buf_ptr++;
    }
  parser_state_tos->comment_delta = 0;
  *e_com++ = '/';		/* put '/*' into buffer */
  *e_com++ = '*';
  if (*buf_ptr != ' ' && !parser_state_tos->box_com)
    *e_com++ = ' ';

  *e_com = '\0';
  if (troff)
    {
      now_col = 1;
      adj_max_col = 80;
    }
  else
    /* figure what column we would be in if we printed the comment now */
    now_col = count_spaces (parser_state_tos->com_col, s_com);

  /* Start to copy the comment */

  while (1)
    {				/* this loop will go until the comment is
				   copied */
      if (*buf_ptr > 040 && *buf_ptr != '*')
	parser_state_tos->last_nl = 0;
      check_com_size;
      switch (*buf_ptr)
	{			/* this checks for various spcl cases */
	case 014:		/* check for a form feed */
	  if (!parser_state_tos->box_com)
	    {			/* in a text comment, break the line here */
	      parser_state_tos->use_ff = true;
	      /* fix so dump_line uses a form feed */
	      dump_line ();
	      last_bl = 0;
	      *e_com++ = ' ';
	      *e_com++ = '*';
	      *e_com++ = ' ';
	      while (*++buf_ptr == ' ' || *buf_ptr == '\t');
	    }
	  else
	    {
	      if (++buf_ptr >= buf_end)
		fill_buffer ();
	      *e_com++ = 014;
	    }
	  break;

	case '\n':
	  if (had_eof)
	    {			/* check for unexpected eof */
	      printf ("Unterminated comment\n");
	      *e_com = '\0';
	      dump_line ();
	      return;
	    }
	  one_liner = 0;
	  if (parser_state_tos->box_com || parser_state_tos->last_nl)
	    {			/* if this is a boxed comment, we dont ignore
				   the newline */
	      if (s_com == e_com)
		{
		  *e_com++ = ' ';
		  *e_com++ = ' ';
		}
	      *e_com = '\0';
	      if (!parser_state_tos->box_com && e_com - s_com > 3)
		{
		  if (break_delim == 1 && s_com[0] == '/'
		      && s_com[1] == '*' && s_com[2] == ' ')
		    {
		      char *t = e_com;
		      break_delim = 2;
		      e_com = s_com + 2;
		      *e_com = 0;
		      if (blanklines_before_blockcomments)
			prefix_blankline_requested = 1;
		      dump_line ();
		      e_com = t;
		      s_com[0] = s_com[1] = s_com[2] = ' ';
		    }
		  dump_line ();
		  check_com_size;
		  *e_com++ = ' ';
		  *e_com++ = ' ';
		}
	      dump_line ();
	      now_col = parser_state_tos->com_col;
	    }
	  else
	    {
	      parser_state_tos->last_nl = 1;
	      if (unix_comment != 1)
		{		/* we not are in unix_style comment */
		  if (unix_comment == 0 && s_code == e_code)
		    {
		      /* if it is a UNIX-style comment, ignore the
		         requirement that previous line be blank for
		         unindention */
		      parser_state_tos->com_col
			= ((parser_state_tos->ind_level - unindent_displace)
			   + ind_size);
		      if (parser_state_tos->com_col <= 1)
			parser_state_tos->com_col = 2;
		    }
		  unix_comment = 2;	/* permanently remember that we are
					   in this type of comment */
		  dump_line ();
		  ++line_no;
		  now_col = parser_state_tos->com_col;
		  *e_com++ = ' ';
		  /* fix so that the star at the start of the line will line
		     up */
		  do		/* flush leading white space */
		    if (++buf_ptr >= buf_end)
		      fill_buffer ();
		  while (*buf_ptr == ' ' || *buf_ptr == '\t');
		  break;
		}
	      if (*(e_com - 1) == ' ' || *(e_com - 1) == '\t')
		last_bl = e_com - 1;
	      /* if there was a space at the end of the last line, remember
	         where it was */
	      else
		{		/* otherwise, insert one */
		  last_bl = e_com;
		  check_com_size;
		  *e_com++ = ' ';
		  ++now_col;
		}
	    }
	  ++line_no;		/* keep track of input line number */
	  if (!parser_state_tos->box_com)
	    {
	      int nstar = 1;
	      do
		{		/* flush any blanks and/or tabs at start of
				   next line */
		  if (++buf_ptr >= buf_end)
		    fill_buffer ();
		  if (*buf_ptr == '*' && --nstar >= 0)
		    {
		      if (++buf_ptr >= buf_end)
			fill_buffer ();
		      if (*buf_ptr == '/')
			goto end_of_comment;
		    }
		}
	      while (*buf_ptr == ' ' || *buf_ptr == '\t');
	    }
	  else if (++buf_ptr >= buf_end)
	    fill_buffer ();
	  break;		/* end of case for newline */

	case '*':		/* must check for possibility of being at end
				   of comment */
	  if (++buf_ptr >= buf_end)	/* get to next char after * */
	    fill_buffer ();

	  if (unix_comment == 0)/* set flag to show we are not in unix-style
				   comment */
	    unix_comment = 1;

	  if (*buf_ptr == '/')
	    {			/* it is the end!!! */
	    end_of_comment:
	      if (++buf_ptr >= buf_end)
		fill_buffer ();

	      if (*(e_com - 1) != ' ' && !parser_state_tos->box_com)
		{		/* insure blank before end */
		  *e_com++ = ' ';
		  ++now_col;
		}
	      if (break_delim == 1 && !one_liner && s_com[0] == '/'
		  && s_com[1] == '*' && s_com[2] == ' ')
		{
		  char *t = e_com;
		  break_delim = 2;
		  e_com = s_com + 2;
		  *e_com = 0;
		  if (blanklines_before_blockcomments)
		    prefix_blankline_requested = 1;
		  dump_line ();
		  e_com = t;
		  s_com[0] = s_com[1] = s_com[2] = ' ';
		}
	      if (break_delim == 2 && e_com > s_com + 3
	      /* now_col > adj_max_col - 2 && !parser_state_tos->box_com */ )
		{
		  *e_com = '\0';
		  dump_line ();
		  now_col = parser_state_tos->com_col;
		}
	      check_com_size;
	      *e_com++ = '*';
	      *e_com++ = '/';
	      *e_com = '\0';
	      parser_state_tos->just_saw_decl = l_just_saw_decl;
	      return;
	    }
	  else
	    {			/* handle isolated '*' */
	      *e_com++ = '*';
	      ++now_col;
	    }
	  break;
	default:		/* we have a random char */
	  if (unix_comment == 0 && *buf_ptr != ' ' && *buf_ptr != '\t')
	    unix_comment = 1;	/* we are not in unix-style comment */

	  *e_com = *buf_ptr++;
	  if (buf_ptr >= buf_end)
	    fill_buffer ();

	  if (*e_com == '\t')	/* keep track of column */
	    now_col = now_col + tabsize - (now_col - 1) % tabsize;
	  else if (*e_com == '\b')	/* this is a backspace */
	    --now_col;
	  else
	    ++now_col;

	  if (*e_com == ' ' || *e_com == '\t')
	    last_bl = e_com;
	  /* remember we saw a blank */

	  ++e_com;
	  if (now_col > adj_max_col
	      && !parser_state_tos->box_com
	      && unix_comment == 1
	      && e_com[-1] > ' ')
	    {
	      /* the comment is too long, it must be broken up */
	      if (break_delim == 1 && s_com[0] == '/'
		  && s_com[1] == '*' && s_com[2] == ' ')
		{
		  char *t = e_com;
		  break_delim = 2;
		  e_com = s_com + 2;
		  *e_com = 0;
		  if (blanklines_before_blockcomments)
		    prefix_blankline_requested = 1;
		  dump_line ();
		  e_com = t;
		  s_com[0] = s_com[1] = s_com[2] = ' ';
		}
	      if (last_bl == 0)
		{		/* we have seen no blanks */
		  last_bl = e_com;	/* fake it */
		  *e_com++ = ' ';
		}
	      *e_com = '\0';	/* print what we have */
	      *last_bl = '\0';
	      while (last_bl > s_com && last_bl[-1] < 040)
		*--last_bl = 0;
	      e_com = last_bl;
	      dump_line ();

	      *e_com++ = ' ';	/* add blanks for continuation */
	      *e_com++ = ' ';
	      *e_com++ = ' ';

	      t_ptr = last_bl + 1;
	      last_bl = 0;
	      if (t_ptr >= e_com)
		{
		  while (*t_ptr == ' ' || *t_ptr == '\t')
		    t_ptr++;
		  while (*t_ptr != '\0')
		    {		/* move unprinted part of comment down in
				   buffer */
		      if (*t_ptr == ' ' || *t_ptr == '\t')
			last_bl = e_com;
		      *e_com++ = *t_ptr++;
		    }
		}
	      *e_com = '\0';
	      /* recompute current position */
	      now_col = count_spaces (parser_state_tos->com_col, s_com);
	    }
	  break;
	}
    }
}