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/* Styling for ui_file
Copyright (C) 2018-2024 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "ui-style.h"
#include "gdbsupport/gdb_regex.h"
/* A regular expression that is used for matching ANSI terminal escape
sequences. */
static const char ansi_regex_text[] =
/* Introduction. */
"^\033\\["
#define DATA_SUBEXP 1
/* Capture parameter and intermediate bytes. */
"("
/* Parameter bytes. */
"[\x30-\x3f]*"
/* Intermediate bytes. */
"[\x20-\x2f]*"
/* End the first capture. */
")"
/* The final byte. */
#define FINAL_SUBEXP 2
"([\x40-\x7e])";
/* The number of subexpressions to allocate space for, including the
"0th" whole match subexpression. */
#define NUM_SUBEXPRESSIONS 3
/* The compiled form of ansi_regex_text. */
static regex_t ansi_regex;
/* This maps bright colors to RGB triples. The index is the bright
color index, starting with bright black. The values come from
xterm. */
static const uint8_t bright_colors[][3] = {
{ 127, 127, 127 }, /* Black. */
{ 255, 0, 0 }, /* Red. */
{ 0, 255, 0 }, /* Green. */
{ 255, 255, 0 }, /* Yellow. */
{ 92, 92, 255 }, /* Blue. */
{ 255, 0, 255 }, /* Magenta. */
{ 0, 255, 255 }, /* Cyan. */
{ 255, 255, 255 } /* White. */
};
/* See ui-style.h. */
bool
ui_file_style::color::append_ansi (bool is_fg, std::string *str) const
{
if (m_simple)
{
if (m_value >= BLACK && m_value <= WHITE)
str->append (std::to_string (m_value + (is_fg ? 30 : 40)));
else if (m_value > WHITE && m_value <= WHITE + 8)
str->append (std::to_string (m_value - WHITE + (is_fg ? 90 : 100)));
else if (m_value != -1)
{
str->append (is_fg ? "38;5;" : "48;5;");
str->append (std::to_string (m_value));
}
else
return false;
}
else
{
str->append (is_fg ? "38;2;" : "48;2;");
str->append (std::to_string (m_red)
+ ";" + std::to_string (m_green)
+ ";" + std::to_string (m_blue));
}
return true;
}
/* See ui-style.h. */
void
ui_file_style::color::get_rgb (uint8_t *rgb) const
{
if (m_simple)
{
/* Can't call this for a basic color or NONE -- those will end
up in the assert below. */
if (m_value >= 8 && m_value <= 15)
memcpy (rgb, bright_colors[m_value - 8], 3 * sizeof (uint8_t));
else if (m_value >= 16 && m_value <= 231)
{
int value = m_value;
value -= 16;
/* This obscure formula seems to be what terminals actually
do. */
int component = value / 36;
rgb[0] = component == 0 ? 0 : (55 + component * 40);
value %= 36;
component = value / 6;
rgb[1] = component == 0 ? 0 : (55 + component * 40);
value %= 6;
rgb[2] = value == 0 ? 0 : (55 + value * 40);
}
else if (m_value >= 232)
{
uint8_t v = (m_value - 232) * 10 + 8;
rgb[0] = v;
rgb[1] = v;
rgb[2] = v;
}
else
gdb_assert_not_reached ("get_rgb called on invalid color");
}
else
{
rgb[0] = m_red;
rgb[1] = m_green;
rgb[2] = m_blue;
}
}
/* See ui-style.h. */
std::string
ui_file_style::to_ansi () const
{
std::string result ("\033[");
bool need_semi = m_foreground.append_ansi (true, &result);
if (!m_background.is_none ())
{
if (need_semi)
result.push_back (';');
m_background.append_ansi (false, &result);
need_semi = true;
}
if (m_intensity != NORMAL)
{
if (need_semi)
result.push_back (';');
result.append (std::to_string (m_intensity));
need_semi = true;
}
if (m_reverse)
{
if (need_semi)
result.push_back (';');
result.push_back ('7');
}
result.push_back ('m');
return result;
}
/* Read a ";" and a number from STRING. Return the number of
characters read and put the number into *NUM. */
static bool
read_semi_number (const char *string, regoff_t *idx, long *num)
{
if (string[*idx] != ';')
return false;
++*idx;
if (string[*idx] < '0' || string[*idx] > '9')
return false;
char *tail;
*num = strtol (string + *idx, &tail, 10);
*idx = tail - string;
return true;
}
/* A helper for ui_file_style::parse that reads an extended color
sequence; that is, and 8- or 24- bit color. */
static bool
extended_color (const char *str, regoff_t *idx, ui_file_style::color *color)
{
long value;
if (!read_semi_number (str, idx, &value))
return false;
if (value == 5)
{
/* 8-bit color. */
if (!read_semi_number (str, idx, &value))
return false;
if (value >= 0 && value <= 255)
*color = ui_file_style::color (value);
else
return false;
}
else if (value == 2)
{
/* 24-bit color. */
long r, g, b;
if (!read_semi_number (str, idx, &r)
|| r > 255
|| !read_semi_number (str, idx, &g)
|| g > 255
|| !read_semi_number (str, idx, &b)
|| b > 255)
return false;
*color = ui_file_style::color (r, g, b);
}
else
{
/* Unrecognized sequence. */
return false;
}
return true;
}
/* See ui-style.h. */
bool
ui_file_style::parse (const char *buf, size_t *n_read)
{
regmatch_t subexps[NUM_SUBEXPRESSIONS];
int match = regexec (&ansi_regex, buf, ARRAY_SIZE (subexps), subexps, 0);
if (match == REG_NOMATCH)
{
*n_read = 0;
return false;
}
/* Other failures mean the regexp is broken. */
gdb_assert (match == 0);
/* The regexp is anchored. */
gdb_assert (subexps[0].rm_so == 0);
/* The final character exists. */
gdb_assert (subexps[FINAL_SUBEXP].rm_eo - subexps[FINAL_SUBEXP].rm_so == 1);
if (buf[subexps[FINAL_SUBEXP].rm_so] != 'm')
{
/* We don't handle this sequence, so just drop it. */
*n_read = subexps[0].rm_eo;
return false;
}
/* Examine each setting in the match and apply it to the result.
See the Select Graphic Rendition section of
https://en.wikipedia.org/wiki/ANSI_escape_code. In essence each
code is just a number, separated by ";"; there are some more
wrinkles but we don't support them all.. */
/* "\033[m" means the same thing as "\033[0m", so handle that
specially here. */
if (subexps[DATA_SUBEXP].rm_so == subexps[DATA_SUBEXP].rm_eo)
*this = ui_file_style ();
for (regoff_t i = subexps[DATA_SUBEXP].rm_so;
i < subexps[DATA_SUBEXP].rm_eo;
++i)
{
if (buf[i] == ';')
{
/* Skip. */
}
else if (buf[i] >= '0' && buf[i] <= '9')
{
char *tail;
long value = strtol (buf + i, &tail, 10);
i = tail - buf;
switch (value)
{
case 0:
/* Reset. */
*this = ui_file_style ();
break;
case 1:
/* Bold. */
m_intensity = BOLD;
break;
case 2:
/* Dim. */
m_intensity = DIM;
break;
case 7:
/* Reverse. */
m_reverse = true;
break;
case 21:
m_intensity = NORMAL;
break;
case 22:
/* Normal. */
m_intensity = NORMAL;
break;
case 27:
/* Inverse off. */
m_reverse = false;
break;
case 30:
case 31:
case 32:
case 33:
case 34:
case 35:
case 36:
case 37:
/* Note: not 38. */
case 39:
m_foreground = color (value - 30);
break;
case 40:
case 41:
case 42:
case 43:
case 44:
case 45:
case 46:
case 47:
/* Note: not 48. */
case 49:
m_background = color (value - 40);
break;
case 90:
case 91:
case 92:
case 93:
case 94:
case 95:
case 96:
case 97:
m_foreground = color (value - 90 + 8);
break;
case 100:
case 101:
case 102:
case 103:
case 104:
case 105:
case 106:
case 107:
m_background = color (value - 100 + 8);
break;
case 38:
/* If we can't parse the extended color, fail. */
if (!extended_color (buf, &i, &m_foreground))
{
*n_read = subexps[0].rm_eo;
return false;
}
break;
case 48:
/* If we can't parse the extended color, fail. */
if (!extended_color (buf, &i, &m_background))
{
*n_read = subexps[0].rm_eo;
return false;
}
break;
default:
/* Ignore everything else. */
break;
}
}
else
{
/* Unknown, let's just ignore. */
}
}
*n_read = subexps[0].rm_eo;
return true;
}
/* See ui-style.h. */
bool
skip_ansi_escape (const char *buf, int *n_read)
{
regmatch_t subexps[NUM_SUBEXPRESSIONS];
int match = regexec (&ansi_regex, buf, ARRAY_SIZE (subexps), subexps, 0);
if (match == REG_NOMATCH || buf[subexps[FINAL_SUBEXP].rm_so] != 'm')
return false;
*n_read = subexps[FINAL_SUBEXP].rm_eo;
return true;
}
void _initialize_ui_style ();
void
_initialize_ui_style ()
{
int code = regcomp (&ansi_regex, ansi_regex_text, REG_EXTENDED);
/* If the regular expression was incorrect, it was a programming
error. */
gdb_assert (code == 0);
}