[PATCH] TUI: Expand TABs into spaces

[Eli Zaretskii]

Ping!  OK to install, master and 7.9 branch?

> Date: Sat, 03 Jan 2015 13:30:08 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> "gdb -tui" relies on the curses library and the underlying terminal
> driver to expand TAB characters into spaces.  But ncurses on Windows
> doesn't do that, and instead displays an IBM graphics character.
> 
> The patches below fix that in the command window and in displaying the
> registers.
> 
> OK to commit?
> 
> 2015-01-03  Eli Zaretskii  <eliz@gnu.org>
> 
> 	* tui/tui-regs.c (tui_register_format): Expand TABs into the
> 	appropriate number of spaces.
> 
> 	* tui/tui-io.c (tui_puts, tui_redisplay_readline): Expand TABs
> 	into the appropriate number of spaces.
> 
> 
> --- gdb/tui/tui-io.c~0	2014-10-29 21:45:50.000000000 +0200
> +++ gdb/tui/tui-io.c	2015-01-03 11:12:52.187500000 +0200
> @@ -179,7 +179,19 @@ tui_puts (const char *string)
>        else if (tui_skip_line != 1)
>          {
>            tui_skip_line = -1;
> -          waddch (w, c);
> +	  if (c == '\t')
> +	    {
> +	      int line, col;
> +
> +	      getyx (w, line, col);
> +	      do
> +		{
> +		  waddch (w, ' ');
> +		  col++;
> +		} while ((col % 8) != 0);
> +	    }
> +	  else
> +	    waddch (w, c);
>          }
>        else if (c == '\n')
>          tui_skip_line = -1;
> @@ -254,6 +266,15 @@ tui_redisplay_readline (void)
>            waddch (w, '^');
>            waddch (w, CTRL_CHAR (c) ? UNCTRL (c) : '?');
>  	}
> +      else if (c == '\t')
> +	{
> +	  getyx (w, line, col);
> +	  do
> +	    {
> +	      waddch (w, ' ');
> +	      col++;
> +	    } while ((col % 8) != 0);
> +	}
>        else
>  	{
>            waddch (w, c);
> 
> 
> --- gdb/tui/tui-regs.c~0	2014-10-29 21:45:50.000000000 +0200
> +++ gdb/tui/tui-regs.c	2015-01-03 12:52:42.062500000 +0200
> @@ -676,8 +676,9 @@ tui_register_format (struct frame_info *
>    struct ui_file *stream;
>    struct ui_file *old_stdout;
>    struct cleanup *cleanups;
> -  char *p, *s;
> +  char *p, *s, *q;
>    char *ret;
> +  int n_adjust, col;
>  
>    pagination_enabled = 0;
>    old_stdout = gdb_stdout;
> @@ -694,7 +695,47 @@ tui_register_format (struct frame_info *
>    if (s && s[1] == 0)
>      *s = 0;
>  
> -  ret = xstrdup (p);
> +  /* Expand tabs into spaces.  */
> +  /* 1. How many additional characters do we need?  */
> +  for (col = n_adjust = 0, s = p; s; )
> +    {
> +      s = strpbrk (s, "\t");
> +      if (s)
> +	{
> +	  col = (s - p) + n_adjust;
> +	  /* Adjustment for the next tab stop, minus one for the TAB
> +	     we replace with spaces.  */
> +	  n_adjust += 8 - (col % 8) - 1;
> +	  s++;
> +	}
> +    }
> +
> +  /* Allocate the copy.  */
> +  ret = q = xmalloc (strlen (p) + n_adjust + 1);
> +
> +  /* 2. Copy the original string while replacing TABs with spaces.  */
> +  for (col = 0, s = p; s; )
> +    {
> +      char *s1 = strpbrk (s, "\t");
> +      if (s1)
> +	{
> +	  if (s1 > s)
> +	    {
> +	      strncpy (q, s, s1 - s);
> +	      q += s1 - s;
> +	      col += s1 - s;
> +	    }
> +	  do {
> +	    *q++ = ' ';
> +	    col++;
> +	  } while ((col % 8) != 0);
> +	  s1++;
> +	}
> +      else
> +	strcpy (q, s);
> +      s = s1;
> +    }
> +
>    do_cleanups (cleanups);
>  
>    return ret;
>