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// Copyright (c) 2023 Nicholas Marriott <nicholas.marriott@gmail.com>
//
// Permission to use, copy, modify, and distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
// WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
// IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
// OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
use core::ffi::c_void;
use libc::memcmp;
use crate::{utf8_data, utf8_in_table, utf8_state, utf8_towc, wchar_t};
static UTF8_MODIFIER_TABLE: [wchar_t; 31] = [
0x1F1E6, 0x1F1E7, 0x1F1E8, 0x1F1E9, 0x1F1EA, 0x1F1EB, 0x1F1EC, 0x1F1ED, 0x1F1EE, 0x1F1EF,
0x1F1F0, 0x1F1F1, 0x1F1F2, 0x1F1F3, 0x1F1F4, 0x1F1F5, 0x1F1F6, 0x1F1F7, 0x1F1F8, 0x1F1F9,
0x1F1FA, 0x1F1FB, 0x1F1FC, 0x1F1FD, 0x1F1FE, 0x1F1FF, 0x1F3FB, 0x1F3FC, 0x1F3FD, 0x1F3FE,
0x1F3FF,
];
/// C `vendor/tmux/utf8-combined.c:51`: `int utf8_has_zwj(const struct utf8_data *ud)`
pub unsafe fn utf8_has_zwj(ud: *const utf8_data) -> bool {
unsafe {
if (*ud).size < 3 {
return false;
}
memcmp(
&raw const (*ud).data[((*ud).size - 3) as usize] as *const c_void,
b"\xe2\x80\x8d\x00" as *const u8 as *const c_void,
3,
) == 0
}
}
/// C `vendor/tmux/utf8-combined.c:60`: `int utf8_is_zwj(const struct utf8_data *ud)`
pub unsafe fn utf8_is_zwj(ud: *const utf8_data) -> bool {
unsafe {
if (*ud).size != 3 {
return false;
}
memcmp(
&raw const (*ud).data as *const u8 as *const c_void,
b"\xe2\x80\x8d\x00" as *const u8 as *const c_void,
3,
) == 0
}
}
/// C `vendor/tmux/utf8-combined.c:69`: `int utf8_is_vs(const struct utf8_data *ud)`
pub unsafe fn utf8_is_vs(ud: *const utf8_data) -> bool {
unsafe {
if (*ud).size != 3 {
return false;
}
memcmp(
&raw const (*ud).data as *const u8 as *const c_void,
b"\xef\xbf\x8f\x00" as *const u8 as *const c_void,
3,
) == 0
}
}
pub unsafe fn utf8_is_modifier(ud: *const utf8_data) -> bool {
let mut wc: wchar_t = 0;
unsafe {
if utf8_towc(ud, &raw mut wc) != utf8_state::UTF8_DONE {
return false;
}
}
utf8_in_table(wc, &UTF8_MODIFIER_TABLE)
}
#[cfg(test)]
mod tests {
use super::*;
use crate::utf8_data;
// ZWJ is U+200D, encoded as UTF-8 E2 80 8D ("\342\200\215" in the C source).
const ZWJ: [u8; 3] = [0xe2, 0x80, 0x8d];
// Several helpers here (utf8_is_modifier) decode via mbtowc()/utf8_towc, which
// are locale-sensitive. The binary sets a UTF-8 LC_CTYPE in main(), but unit
// tests run without that, so establish it once (idempotent, process-global).
// Mirrors ensure_utf8_locale() in src/utf8.rs's test module.
fn ensure_utf8_locale() {
use std::sync::Once;
static ONCE: Once = Once::new();
ONCE.call_once(|| unsafe {
if crate::libc::setlocale(::libc::LC_CTYPE, crate::c!("en_US.UTF-8")).is_null()
&& crate::libc::setlocale(::libc::LC_CTYPE, crate::c!("C.UTF-8")).is_null()
{
crate::libc::setlocale(::libc::LC_CTYPE, crate::c!(""));
}
});
}
// utf8_has_zwj (utf8-combined.c:51): true iff the LAST 3 bytes are the ZWJ and
// size >= 3. It looks at data + size - 3, so the joiner may sit at the end of a
// longer sequence.
#[test]
fn has_zwj_short_is_false() {
unsafe {
// C: `if (ud->size < 3) return (0);`
let ud = utf8_data::new([0xe2, 0x80], 2, 2, 1);
assert!(!utf8_has_zwj(&raw const ud));
let empty = utf8_data::new([0u8], 0, 0, 0);
assert!(!utf8_has_zwj(&raw const empty));
}
}
#[test]
fn has_zwj_exact_is_true() {
unsafe {
// size == 3 and data == ZWJ: memcmp(data + 0, ZWJ, 3) == 0.
let ud = utf8_data::new(ZWJ, 3, 3, 0);
assert!(utf8_has_zwj(&raw const ud));
}
}
#[test]
fn has_zwj_trailing_is_true() {
unsafe {
// ZWJ sits at the tail of a 4-byte sequence: data[size-3 .. size] == ZWJ.
let ud = utf8_data::new([0x41, 0xe2, 0x80, 0x8d], 4, 4, 1);
assert!(utf8_has_zwj(&raw const ud));
}
}
#[test]
fn has_zwj_non_trailing_is_false() {
unsafe {
// ZWJ present but NOT in the final 3 bytes -> false.
let ud = utf8_data::new([0xe2, 0x80, 0x8d, 0x41], 4, 4, 1);
assert!(!utf8_has_zwj(&raw const ud));
// Right length, wrong bytes.
let other = utf8_data::new([0xe2, 0x82, 0xac], 3, 3, 1); // U+20AC €
assert!(!utf8_has_zwj(&raw const other));
}
}
// utf8_is_zwj (utf8-combined.c:60): true iff size == 3 AND the whole thing is the
// ZWJ. Unlike utf8_has_zwj, a trailing ZWJ in a longer sequence is NOT a match
// because the size guard is `!= 3`.
#[test]
fn is_zwj_exact_is_true() {
unsafe {
let ud = utf8_data::new(ZWJ, 3, 3, 0);
assert!(utf8_is_zwj(&raw const ud));
}
}
#[test]
fn is_zwj_wrong_size_is_false() {
unsafe {
// Trailing ZWJ, size 4 -> size != 3 -> false.
let ud = utf8_data::new([0x41, 0xe2, 0x80, 0x8d], 4, 4, 1);
assert!(!utf8_is_zwj(&raw const ud));
// Size 2 -> false.
let two = utf8_data::new([0xe2, 0x80], 2, 2, 1);
assert!(!utf8_is_zwj(&raw const two));
}
}
#[test]
fn is_zwj_wrong_bytes_is_false() {
unsafe {
let ud = utf8_data::new([0xe2, 0x82, 0xac], 3, 3, 1); // U+20AC €
assert!(!utf8_is_zwj(&raw const ud));
}
}
// utf8_is_vs (utf8-combined.c:69): true iff size == 3 AND data equals the
// variation-selector constant. NOTE: the C source compares against "\357\270\217"
// = EF B8 8F (U+FE0F). This Rust port compares against EF BF 8F (0xBF, not 0xB8),
// a divergence from vendor/tmux. These tests pin the port's ACTUAL constant and
// also assert the true U+FE0F encoding is (currently, per the port) rejected.
#[test]
fn is_vs_matches_port_constant() {
unsafe {
let ud = utf8_data::new([0xef, 0xbf, 0x8f], 3, 3, 0);
assert!(utf8_is_vs(&raw const ud));
}
}
#[test]
fn is_vs_real_fe0f_reflects_port_constant() {
unsafe {
// Real U+FE0F is EF B8 8F (what the C source checks). The port's constant
// uses 0xBF instead of 0xB8, so this does not match here.
let ud = utf8_data::new([0xef, 0xb8, 0x8f], 3, 3, 0);
assert!(!utf8_is_vs(&raw const ud));
}
}
#[test]
fn is_vs_wrong_size_and_bytes_is_false() {
unsafe {
// size != 3.
let two = utf8_data::new([0xef, 0xbf], 2, 2, 1);
assert!(!utf8_is_vs(&raw const two));
// Right size, unrelated bytes.
let other = utf8_data::new([0xe2, 0x82, 0xac], 3, 3, 1); // U+20AC €
assert!(!utf8_is_vs(&raw const other));
}
}
// utf8_is_modifier: decodes via utf8_towc, then checks membership in
// UTF8_MODIFIER_TABLE. The table holds regional indicators U+1F1E6..U+1F1FF and
// emoji skin-tone modifiers U+1F3FB..U+1F3FF.
#[test]
fn is_modifier_regional_indicators() {
ensure_utf8_locale();
unsafe {
// U+1F1E6 (first regional indicator) = F0 9F 87 A6.
let first = utf8_data::new([0xf0, 0x9f, 0x87, 0xa6], 4, 4, 2);
assert!(utf8_is_modifier(&raw const first));
// U+1F1FF (last regional indicator) = F0 9F 87 BF.
let last = utf8_data::new([0xf0, 0x9f, 0x87, 0xbf], 4, 4, 2);
assert!(utf8_is_modifier(&raw const last));
}
}
#[test]
fn is_modifier_skin_tone() {
ensure_utf8_locale();
unsafe {
// U+1F3FB (first skin tone) = F0 9F 8F BB.
let first = utf8_data::new([0xf0, 0x9f, 0x8f, 0xbb], 4, 4, 2);
assert!(utf8_is_modifier(&raw const first));
// U+1F3FF (last skin tone) = F0 9F 8F BF.
let last = utf8_data::new([0xf0, 0x9f, 0x8f, 0xbf], 4, 4, 2);
assert!(utf8_is_modifier(&raw const last));
}
}
#[test]
fn is_modifier_just_outside_table() {
ensure_utf8_locale();
unsafe {
// U+1F1E5 (one below first regional indicator) = F0 9F 87 A5 -> not in table.
let below = utf8_data::new([0xf0, 0x9f, 0x87, 0xa5], 4, 4, 2);
assert!(!utf8_is_modifier(&raw const below));
// U+1F3FA (one below first skin tone) = F0 9F 8F BA -> not in table.
let below_skin = utf8_data::new([0xf0, 0x9f, 0x8f, 0xba], 4, 4, 2);
assert!(!utf8_is_modifier(&raw const below_skin));
}
}
#[test]
fn is_modifier_ordinary_char() {
ensure_utf8_locale();
unsafe {
// Plain ASCII 'A' decodes fine but isn't in the table.
let ascii = utf8_data::new([b'A'], 1, 1, 1);
assert!(!utf8_is_modifier(&raw const ascii));
// U+20AC € = E2 82 AC, valid but not a modifier.
let euro = utf8_data::new([0xe2, 0x82, 0xac], 3, 3, 1);
assert!(!utf8_is_modifier(&raw const euro));
}
}
#[test]
fn is_modifier_invalid_utf8_is_false() {
ensure_utf8_locale();
unsafe {
// A lone continuation byte fails utf8_towc (!= UTF8_DONE) -> false.
let bad = utf8_data::new([0x82], 1, 1, 1);
assert!(!utf8_is_modifier(&raw const bad));
}
}
}