gcc/color-macros.h

   1 /* Terminal color manipulation macros.
   2    Copyright (C) 2005-2020 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 */