1  /* Terminal color manipulation macros.
       2     Copyright (C) 2005-2023 Free Software Foundation, Inc.
       3  
       4  This file is part of GCC.
       5  
       6  GCC is free software; you can redistribute it and/or modify it under
       7  the terms of the GNU General Public License as published by the Free
       8  Software Foundation; either version 3, or (at your option) any later
       9  version.
      10  
      11  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      12  WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14  for more details.
      15  
      16  You should have received a copy of the GNU General Public License
      17  along with GCC; see the file COPYING3.  If not see
      18  <http://www.gnu.org/licenses/>.  */
      19  
      20  #ifndef GCC_COLOR_MACROS_H
      21  #define GCC_COLOR_MACROS_H
      22  
      23  /* Select Graphic Rendition (SGR, "\33[...m") strings.  */
      24  /* Also Erase in Line (EL) to Right ("\33[K") by default.  */
      25  /*    Why have EL to Right after SGR?
      26  	 -- The behavior of line-wrapping when at the bottom of the
      27  	    terminal screen and at the end of the current line is often
      28  	    such that a new line is introduced, entirely cleared with
      29  	    the current background color which may be different from the
      30  	    default one (see the boolean back_color_erase terminfo(5)
      31  	    capability), thus scrolling the display by one line.
      32  	    The end of this new line will stay in this background color
      33  	    even after reverting to the default background color with
      34  	    "\33[m', unless it is explicitly cleared again with "\33[K"
      35  	    (which is the behavior the user would instinctively expect
      36  	    from the whole thing).  There may be some unavoidable
      37  	    background-color flicker at the end of this new line because
      38  	    of this (when timing with the monitor's redraw is just right).
      39  	 -- The behavior of HT (tab, "\t") is usually the same as that of
      40  	    Cursor Forward Tabulation (CHT) with a default parameter
      41  	    of 1 ("\33[I"), i.e., it performs pure movement to the next
      42  	    tab stop, without any clearing of either content or screen
      43  	    attributes (including background color); try
      44  	       printf 'asdfqwerzxcv\rASDF\tZXCV\n'
      45  	    in a bash(1) shell to demonstrate this.  This is not what the
      46  	    user would instinctively expect of HT (but is ok for CHT).
      47  	    The instinctive behavior would include clearing the terminal
      48  	    cells that are skipped over by HT with blank cells in the
      49  	    current screen attributes, including background color;
      50  	    the boolean dest_tabs_magic_smso terminfo(5) capability
      51  	    indicates this saner behavior for HT, but only some rare
      52  	    terminals have it (although it also indicates a special
      53  	    glitch with standout mode in the Teleray terminal for which
      54  	    it was initially introduced).  The remedy is to add "\33K"
      55  	    after each SGR sequence, be it START (to fix the behavior
      56  	    of any HT after that before another SGR) or END (to fix the
      57  	    behavior of an HT in default background color that would
      58  	    follow a line-wrapping at the bottom of the screen in another
      59  	    background color, and to complement doing it after START).
      60  	    Piping GCC's output through a pager such as less(1) avoids
      61  	    any HT problems since the pager performs tab expansion.
      62  
      63        Generic disadvantages of this remedy are:
      64  	 -- Some very rare terminals might support SGR but not EL (nobody
      65  	    will use "gcc -fdiagnostics-color" on a terminal that does not
      66  	    support SGR in the first place).
      67  	 -- Having these extra control sequences might somewhat complicate
      68  	    the task of any program trying to parse "gcc -fdiagnostics-color"
      69  	    output in order to extract structuring information from it.
      70        A specific disadvantage to doing it after SGR START is:
      71  	 -- Even more possible background color flicker (when timing
      72  	    with the monitor's redraw is just right), even when not at the
      73  	    bottom of the screen.
      74        There are no additional disadvantages specific to doing it after
      75        SGR END.
      76  
      77        It would be impractical for GCC to become a full-fledged
      78        terminal program linked against ncurses or the like, so it will
      79        not detect terminfo(5) capabilities.  */
      80  
      81  #define COLOR_SEPARATOR		";"
      82  #define COLOR_NONE		"00"
      83  #define COLOR_BOLD		"01"
      84  #define COLOR_UNDERSCORE	"04"
      85  #define COLOR_BLINK		"05"
      86  #define COLOR_REVERSE		"07"
      87  #define COLOR_FG_BLACK		"30"
      88  #define COLOR_FG_RED		"31"
      89  #define COLOR_FG_GREEN		"32"
      90  #define COLOR_FG_YELLOW		"33"
      91  #define COLOR_FG_BLUE		"34"
      92  #define COLOR_FG_MAGENTA	"35"
      93  #define COLOR_FG_CYAN		"36"
      94  #define COLOR_FG_WHITE		"37"
      95  #define COLOR_BG_BLACK		"40"
      96  #define COLOR_BG_RED		"41"
      97  #define COLOR_BG_GREEN		"42"
      98  #define COLOR_BG_YELLOW		"43"
      99  #define COLOR_BG_BLUE		"44"
     100  #define COLOR_BG_MAGENTA	"45"
     101  #define COLOR_BG_CYAN		"46"
     102  #define COLOR_BG_WHITE		"47"
     103  #define SGR_START		"\33["
     104  #define SGR_END			"m\33[K"
     105  #define SGR_SEQ(str)		SGR_START str SGR_END
     106  #define SGR_RESET		SGR_SEQ("")
     107  
     108  #endif  /* GCC_COLOR_MACROS_H */