Adds tools/difftest: a Zig driver built against a copy of Ghostty
1.3.1's own src/terminal (Zig 0.15.2, set up under target/ by
tools/difftest/setup.sh) and a Rust twin on ghostty-terminal, both
printing a canonical dump of every scrollback/active row (cells,
graphemes, styles, hyperlinks, row flags), cursor, modes, regions,
tabstops and colors. A seeded generator produces escape-heavy streams
(UTF-8/wide/combining/emoji, C0, CSI with edge params, SGR, modes, ESC,
OSC, DCS, margins, insert/delete); `just difftest` runs it with Zig
assertions on (ReleaseSafe vs debug Rust) and off (ReleaseFast vs
production Rust), with minimizers and a triage script.
Divergences found and fixed in Rust (each with a regression test):
- ill-formed UTF-8 decoding follows the SIMD path a default Ghostty
build uses (not Zig's scalar fallback)
- PageList::erase_rows keeps Zig's row-flag behavior on regrow
- grapheme move on wrap with left/right margins uses the original cell
Upstream bugs found and deliberately NOT replicated (per the project
rule): a stale cell pointer after page growth in Terminal.zig:482/539
that drops a grapheme, plus several Zig assertion failures/segfaults;
documented with minimized repros in docs/rewrite/notes/difftest-DF.md.
Final run: 390k cases across many geometries, 0 divergences (Zig-abort
cases, ~0.1-0.5%, are not compared).
Test Plan:
- just difftest 20000 "1 2 3"
- cargo test -p ghostty-terminal (regression tests)
Resolves the 8 gaps in docs/rewrite/notes/review-rv10-codex.md
(final-Z13.md):
- P1 memory safety: the C key-table action (and hovered-link/open-URL
payloads) could advertise a length larger than the NUL-truncated
allocation. A counted_bytes helper now passes the full bytes plus a
trailing NUL with len == byte count, like Zig's backing slices; all
C pointer+len structs were audited and tested to read exactly len.
- ghostty-bench args follow cli/args.zig (ordered duplicates, empty
value resets, first bad value errors, parseBool spellings); the C
benchmark tokenizer uses the ArgIteratorGeneral port.
- OSC 7 derived titles, desktop notifications and OSC 8 hover links
forward raw bytes to the runtime; GTK converts only for display.
- C diagnostic getter exports original bytes; escaped surrogates report
Utf8CannotEncodeSurrogateHalf; config float formatters print `nan`.
- Config::finalize_for(AppRuntime): GTK-only finalization (gtk-single-
instance=detect) and termio's cgroup hooks apply only to the GTK
runtime, so libghostty keeps `detect` like Zig.
Test Plan:
- cargo test --workspace --no-fail-fast (exit 0)
- cargo test -p ghostty-lib --features test-platform
- just check-wasm (macOS/Windows clippy re-run after the concurrent
terminal changes land)
Rust's str::parse accepts and rejects different inputs than Zig's
std.fmt.parseInt/parseFloat (underscores, base prefixes, signs). The
config layer already used the Zig ports; now the protocol parsers do
too (call site -> Zig reference -> status in final-Z12.md):
- zig_fmt moves into the leaf crate ghostty-zigfmt (ghostty-vt cannot
depend on ghostty-os); ghostty-os re-exports it unchanged.
- ghostty-vt: kitty graphics keys, kitty text sizing, OSC 4/5/10-19
color indices, hex color components and intensities, OSC 9 sleep and
progress, OSC 133 exit codes, OSC 3008 fields, kitty color palette.
- ghostty-terminal: tmux layout, format variables and pane tabs.
- ghostty-os: URI ports and %XX decoding; ghostty-bench CLI arguments.
Expected values were cross-checked against the real Zig toolchain.
Test Plan:
- cargo test --workspace --no-fail-fast
- just check-macos (both), just check-windows, just check-wasm
Resolves the 6 differential gap groups in docs/rewrite/notes/review-
rv9-codex.md (details in final-Z11.md):
- ghostty_os::zig_fmt ports std.fmt.parseInt/parseUnsigned/parseFloat
(underscores, 0x/0o/0b prefixes, hex floats, inf/nan) with the Zig std
tests and replaces every int/float parse in config, keybind
parameters, ssh-cache and desktop detection.
- Interior NUL no longer panics in font names and ends C strings like
Zig's backing bytes (fontconfig, C config getters, title actions,
clipboard callback, relative paths, config-file, shaders, background
image, GTK CSS).
- GTK new-window arguments are trimmed of ASCII whitespace only.
- Command tokenization uses a port of std.process.ArgIteratorGeneral
(incl. CR/LF separators) with its std tests.
- UTF-8 validation happens where Zig's field parsers do it, so error
kinds match (metric modifiers, quick-terminal size, link, ...).
A scripted differential run of 202 fields x ~220 hostile/valid values
against /usr/bin/ghostty (+validate-config and +show-config: exit code,
stdout, stderr) now has zero mismatches besides build-specific defaults
(theme resources path, auto-update-channel, gtk-opengl-debug); it also
surfaced and fixed background-blur failure state, NaN formatting and
NaN/-0 finalize clamps. Regression tests: ghostty-config/tests/
zig_parity.rs.
Test Plan:
- cargo test --workspace --no-fail-fast (3456 passed, exit 0)
- just check-macos (both), just check-windows, just check-wasm
Zig parses config values (cli/args.zig, Config.zig field parsers,
config/string.zig) from raw byte slices, and each field type decides
whether it requires UTF-8 (InvalidValue otherwise) or stores bytes. The
port escape-encoded raw bytes into Strings at the line reader and let
fields parse the escaped text, so fields could observe encoding
artifacts; successive audits kept finding such leaks (RV5-RV8).
Field parsers now receive the original bytes: text fields validate UTF-8
where Zig does, byte/path fields store bytes (EncodedOs/OsString). This
resolves all 9 RV8 findings (docs/rewrite/notes/review-rv8-codex.md),
each with a regression test: Windows path conversion fails with
BadPathName instead of substituting U+FFFD; Windows process launch uses
strict UTF-8 like Zig's Command; the WTF-8 decoder accepts paired-
surrogate encodings like Zig; literal U+FDD0 Unicode key triggers;
selection-word-chars and clipboard-codepoint-map reject invalid UTF-8;
font style / codepoint-map family names use original bytes; C title
actions forward bytes; D-Bus new-window/Flatpak conversions match Zig.
Design, sweep and validation: docs/rewrite/notes/final-bytes-refactor.md.
Also moves the bundled iTerm2-Color-Schemes license out of
resources/themes/ so +list-themes no longer lists it as a theme
(output is now byte-identical to Ghostty 1.3.1).
Done by Codex (gpt-6-astra), reviewed and verified by the orchestrator.
Test Plan:
- cargo test --workspace --no-fail-fast (3428 passed, exit 0)
- just check-macos (both), just check-windows, just check-wasm
- +show-config --default --docs, +list-keybinds, +list-actions --docs,
+list-themes --plain compared with /usr/bin/ghostty
Zig's KeyEvent.utf8 and the embedded API's key/preedit text are byte
slices passed through to key encoding and the pty; the port converted
them lossily to UTF-8.
- KeyEvent.utf8 is &[u8] end to end (ghostty-input encoder, core,
ghostty-lib C API, libghostty-vt key events, GTK callers). Where Zig
validates with Utf8View (alternates, modify-other-keys, ctrl CSI-u,
associated text, binding unicode lookup) invalid text takes the same
"no UTF-8" fallback.
- Invalid preedit UTF-8 behaves like Zig's `try Utf8View.init`: the
prior preedit is cleared and marked dirty, the callback returns an
error (logged by the C API) and no preedit is set.
- The inspector key widget shows invalid key text lossily, display only.
Test Plan:
- cargo test --workspace --no-fail-fast (3407 passed)
- cargo test -p ghostty-lib --features test-platform (C-API key text
0xff 0xfe reaches the pty unchanged)
- just check-macos (both), just check-windows, just check-wasm
Resolves the 9 gap groups in docs/rewrite/notes/review-rv7-codex.md and
audits every string-typed config field against its consumers
(field -> consumers -> decode status table in final-Z9.md):
- Windows EnvMap keys use a port of Zig's nls.zig uppercase table
(upcaseW); Windows locale init follows Zig's chain (setlocale +
_putenv_s); malformed WTF-8 now fails process launch conversions like
Zig instead of substituting U+FFFD; kitty file paths convert WTF-8.
- bash --rcfile/--init-file, configured TERM and inherited GTK LANG
keep their original bytes.
- C API clipboard completion and ghostty_surface_binding_action take
bytes; complete_clipboard_request is byte-typed through the core.
- text:/csi:/esc: bindings, enquiry-response, input = path:, embedded
initial_input, search needles, titles, link regexes, clipboard
codepoint map, command palette text and GTK font/namespace values
decode the escape encoding before use.
Remaining by design: D-Bus a{ss} values and +new-window arguments are
UTF-8 by D-Bus type. C API key/preedit text follows separately.
Test Plan:
- cargo test --workspace
- just check-macos (both), just check-windows, just check-wasm
Resolves the 7 gap groups in docs/rewrite/notes/review-rv6-codex.md
(final-Z8.md):
- crash (macOS): request_abort_dump returns false on mach_msg receive
timeout/error so the signal-path fallback runs; EXC_SOFT_SIGNAL keeps
the signal number in the minidump exception info.
- Default SHELL read as an OS string and stored in encoded command form.
- macOS executable search works on raw PATH bytes; the default path is
used only when PATH is unset.
- Windows: config env overrides are decoded; EnvMap compares keys as
WTF-16 units with per-unit Unicode simple uppercasing (no lossy
conversion, distinct lone-surrogate keys stay distinct).
- +show-config writes original bytes for encoded OS data, so export +
reload round-trips; UTF-8 configs are byte-identical as before.
- Zig's ensureLocale chain lives in ghostty-os for all Unix targets and
is used by both the GTK app and the C API init.
Also makes the quick-terminal GTK replay test independent of compositor
focus: GTK's is-active is read-only, so when niri actually focuses the
layer surface the simulated focus-out cannot drive autohide and that
assertion is skipped (the production logic is unchanged and matches Zig).
Test Plan:
- cargo test --workspace (3390 passed, incl. tests/gtk_replay.rs)
- just check-macos (both), just check-windows, just check-wasm
Escaped config strings (ghostty_os::osbytes) kept reaching OS
boundaries undecoded, and decoding was occasionally applied to plain
text. The root cause was that both were plain `String`s. Now:
- `EncodedOs` is a newtype (no Display/AsRef<Path>) that decodes only
via to_os/to_path/to_bytes/to_wide; plain text enters via
from_plain_text. OS helpers (env, home, xdg, passwd, resources dir,
path expansion), config::Path, WorkingDirectory, theme/file_load/edit
paths, terminal pwd, OpenUrl/Pwd actions and termio cwd use it, so the
compiler forces decoding at every boundary. os::open takes &OsStr.
Config output is unchanged.
Fixes all rows of docs/rewrite/notes/review-rv5-codex.md (final-Z7.md):
screen-file copy; regex/OSC 8 URLs no longer decoded (regression);
lossless Windows WTF-8/WTF-16 for args, env and CreateProcessW; Windows
resources dir/TERMINFO; color OSC request lists and X11 color lookup no
longer allocate globally (C zero-allocation test extended); macOS Mach
handler resumes all threads before KERN_FAILURE (hang regression) and
SIGABRT minidumps go through the exception thread; plus open-config,
background images, crash dir, ssh cache, exe dir/PATH, fontconfig
filenames, file links, kitty TMPDIR, .hushlogin and benchmark paths.
The typing also surfaced and fixed gtk-custom-css, bell audio, bash
HISTFILE, OSC 52 writes and the C config getters.
Test Plan:
- cargo test --workspace (3376 passed)
- just check-macos (both), just check-windows, just check-wasm
- diff <(ghostty-rs +show-config --default --docs) \
<(ghostty +show-config --default --docs)
Ghostty links sentry-native with the breakpad backend on every platform
(SharedDeps.zig), so it writes minidumps on macOS and Windows as well.
- macOS: a Mach exception port handler thread (structured like
Breakpad's exception_handler) catches EXC_BAD_ACCESS/BAD_INSTRUCTION/
ARITHMETIC/BREAKPOINT, suspends other threads, reads the crashed
thread state and writes a minidump via minidump-writer as the
event.minidump attachment, then restores the previous ports so the
BSD signal and default termination follow. The signal path remains
the fallback (and handles SIGABRT); a watchdog alarm bounds dumping.
- Windows: SetUnhandledExceptionFilter hands off to a pre-started dump
thread using minidump-writer's dump_crash_context.
- The screen-file open action decodes the escaped path to raw OS bytes
(also for the C action passed to embedders).
macOS/Windows code is compile-checked (clippy -D warnings) only; the
shared Mach message decoding and minidump attachment logic have Linux
unit tests. Platform matrix in docs/rewrite/notes/crash-CR.md.
Test Plan:
- cargo test --workspace (3348 passed)
- just check-macos; just check-macos x86_64-apple-darwin; just check-windows
Resolves the 13 rows still partial in docs/rewrite/notes/review-rv4-
codex.md (details in final-Z5.md):
- Escaped config strings are decoded to raw bytes at every OS boundary:
Flatpak cwd/argv to D-Bus, screen-file paths, the default config
template, GHOSTTY_RESOURCES_DIR/TERMINFO/shell integration/
bindtextdomain consumers, custom shader loading, list-themes hyperlinks.
- osbytes escapes literal U+FDD0 on non-Unix too (bijective everywhere);
the GTK paste dialog only decodes text that was actually encoded.
- shadertoy: whole-array uses of iChannelTime rebuild a plain float[4]
from the std140-padded members (naga-validated, MSL offsets checked).
- libghostty-vt: the OSC parser holds caller-allocated storage inline
and command payloads borrow from it, so ghostty_osc_end performs no
global allocations (verified from Rust and C).
- crash: aarch64 Linux minidump context fixed; macOS fatal signals record
siginfo, registers and a fault-safe stack walk.
- tripwire: selectionString map allocation-failure cleanup test ported.
- libghostty-vt emits the versioned soname libghostty-vt.so.0 at build
time (no patchelf needed at install).
Test Plan:
- cargo test --workspace (3342 passed)
- just check-macos; just check-macos x86_64-apple-darwin;
just check-windows; just check-wasm
- cargo check --target aarch64-unknown-linux-gnu -p ghostty-crash
Zig treats paths, arguments and environment values as byte slices; the
port converted them lossily in many places. Now (final-Z1.md):
- argv, env (incl. present non-UTF-8 values), HOME, PATH lookup,
passwd, resources dir, TMPDIR, cgroup, config path canonicalization,
+validate-config, +list-themes and Zig-string escapes (\xFF) keep raw
bytes. String-based config values carry bytes via ghostty_os::osbytes,
a bijective escape (noncharacter U+FDD0 + byte) that leaves all valid
UTF-8 - including Nerd Font private-use icons - unchanged.
- os/file rlimit fallbacks exist on all targets.
- i18n locale canonicalization is an exact port of libintl's tables
(e.g. pa-Guru -> pa_IN).
- New ghostty-build-info crate is the single source of version, channel,
commit and build mode for all consumers.
Test Plan:
- cargo test -p ghostty-os -p ghostty-config -p ghostty-cli
(incl. randomized osbytes round-trip property tests)
Closes the remaining artifact rows of the final audit
(docs/rewrite/notes/final-Z4.md):
- webgen: config.mdx, actions.mdx, commands.mdx (byte-identical to
Zig's webgen output once its missing stdout flush is added)
- `just install-lib`: libghostty (+ ghostty.h, modulemap) and
libghostty-vt with versioned symlinks, headers and libghostty-vt.pc
- scripts/xcframework.sh: per-arch builds, lipo and
xcodebuild -create-xcframework for GhosttyKit (dry-run verified only)
- `just install` builds --profile production so the installed app id is
com.mitchellh.ghostty; other profiles install the -debug id/name
- `just update-translations`: xgettext/msgmerge pipeline; extracted
msgids equal upstream's .pot (found and fixed an untranslated string
in the child-exited banner)
- `just dist` / `distcheck`: versioned source tarball with VERSION and a
prebuilt GTK resource bundle
- Windows: icon, version resource and DPI/common-controls manifest
embedded via embed-resource, GUI subsystem
Test Plan:
- just install-lib /tmp/p release all && pkg-config --cflags \
--libs /tmp/p/share/pkgconfig/libghostty-vt.pc
- just distcheck
Closes the remaining library rows of the final completeness audit
(docs/rewrite/notes/final-Z3.md):
- libghostty-vt: OSC parser storage goes through the caller-supplied C
allocator via a ByteStorage abstraction; ghostty_osc_new reports
GHOSTTY_OUT_OF_MEMORY and failed grows invalidate the OSC like Zig.
Tested with a counting/failing/limiting C allocator.
- shadertoy: sampler parameter rewriting is keyed by full signature so
overloads work; the Metal uniform block keeps std140 strides for
iChannelTime[4] (MSL offsets checked against the upload layout).
- tripwire.zig ported (named trip points, hit counts, verification) and
used to port the previously skipped allocation-failure tests that have
a fallible Rust path; the rest are documented.
- crash: fatal signals capture siginfo + registers and a forked helper
writes a minidump (minidump-writer) as an envelope attachment, like
sentry-native/Breakpad; tests parse it with the minidump crate.
- kitty LoadingImage::debug_dump (debug builds) and the Darwin
Instruments signpost around benchmark runs.
Test Plan:
- cargo test -p ghostty-vt-capi --test c_allocator
- cargo test -p ghostty-crash --test minidump
Ports apprt/embedded.zig, main_c.zig and config/CApi.zig + c_get.zig as
crates/ghostty-lib (cdylib/staticlib/rlib `libghostty`), exporting every
function of the unchanged include/ghostty.h - the ABI Ghostty's Swift
macOS/iOS app links against. The embedded runtime implements the
runtime traits over the host's C callbacks, so the real core drives it.
- ghostty-core selects the renderer per target: Metal on Apple (surface
NSView/UIView via RtSurface::platform_view), OpenGL elsewhere.
- ghostty_config_get follows Zig's c_get rules via a CValue type (143
supported keys, checked against the Zig field types).
- The inspector C API is complete; its Metal backend replaces ImGui's
Metal renderer and has not run.
Verification: generated C ABI probe (sizeof/alignof/offsetof of every
struct/union, 755 enum values, every function linked, nm exports, headers
byte-identical to upstream); a C host on Linux covering init, CLI
actions, config, app, keys, focus and color scheme; an opt-in
test-platform feature creating real surfaces on Linux with headless EGL
and a pty (13 tests). Apple targets are clippy-clean but not run; the
Swift app has not been built against it.
Test Plan:
- cargo test -p ghostty-lib (and --features test-platform)
- cargo clippy --target aarch64-apple-darwin -p ghostty-lib (cross env
in docs/rewrite/notes/macos-M1.md)
- apprt-gtk: Ghostty's runtime+build-time version gating (at_least)
with cargo features adw_1_3/adw_1_4/adw_1_5/gtk_4_16 (default on) and
the fallbacks for older libraries: MessageDialog (adw < 1.5),
clipboard dialog without SwitchRow, pre-Banner debug warning and
child-exited widgets, the old about dialog, GTK 4.16 CSS error source
bytes. The minimum stays GTK 4.14 / libadwaita 1.5 (Ghostty's floor).
The root build links with -z lazy so version-gated symbols don't keep
older libraries from loading.
- ghostty-helpgen (port of helpgen.zig) generates CLI action help and
keybinding action docs from doc comments at build time, replacing the
checked-in help/*.txt; +help and +list-actions --docs stay
byte-identical to Ghostty 1.3.1.
- ghostty-bench: libc wcwidth mode and separate simd/table and
uucode/table code paths like Zig.
- ghostty-cli: Windows branches of edit-config, list-colors,
list-keybinds and boo; ssh-cache DiskCache flock locking (no-op on
Windows, as in Zig) with an exclusivity test.
Test Plan:
- cargo test --workspace
- diff <(cargo run -q -- +list-actions --docs) \
<(ghostty +list-actions --docs)
Ports the macOS-specific Zig code behind cfg(target_os = "macos"):
- renderer: a GraphicsApi trait with generic::Renderer<G>; Metal backend
(all renderer/metal/* files, shaders.metal verbatim, runtime library
compile, IOSurface layer, CVDisplayLink), shadertoy -> MSL via naga;
OpenGL remains the backend elsewhere.
- font: CoreText face, shaper and discovery with build.rs backend
selection (coretext default; coretext-freetype / coretext-harfbuzz /
coretext-noshape features), no fontconfig/freetype/harfbuzz on Apple.
- input: KeymapDarwin via UCKeyTranslate, option-as-alt, mac keycodes.
- os: macos, mach, cf_release_thread, NSProcessInfo args and macOS
branches; config: macOS defaults, keybinds, Application Support paths.
- termio/core: login(1) wrapping, openpty/execvpe, Darwin child exit
handling, os_log logging.
Compile-checked for aarch64/x86_64-apple-darwin (clippy -D warnings
clean) using the cross setup in docs/rewrite/notes/macos-M1.md; cannot
run here. The embedded runtime/C API (embedded.zig) is the next step.
Also includes the cross-platform integration edits shared by the crash,
verification, Windows and macOS work (Cargo target-gating, thread
crash-context hooks, apprt-gtk surface/IME refactor, termio/os cfg
gates), a cfg fix so ghostty-config builds on wasm32, and an allow for
the intentional recursion in the crash overflow test.
Test Plan:
- cargo test --workspace (3224 passed)
- cargo clippy --workspace --all-targets -- -D warnings
- cargo check --target aarch64-apple-darwin -p ghostty-renderer (with
the documented cross env)
Ports the Windows branches of the Zig code behind cfg(windows):
ConPTY pty (CreatePseudoConsole, pipes, resize), CreateProcessW with the
pseudo-console attribute list, env blocks and command-line quoting, a
pipe read thread with CancelIoEx and a WaitForMultipleObjects IO loop,
plus os helpers (home dir, env, paths, temp dirs, hostname, XDG via
LOCALAPPDATA) and config/input/terminal/crash Windows branches.
Compile-checked with `cargo check --target x86_64-pc-windows-gnu` for
vt, unicode, datastruct, input, os, config, terminal and termio (setup
in docs/rewrite/notes/windows-WIN.md); cannot run here.
Platform-independent pieces (quoting with a CommandLineToArgvW
round-trip, env block encoding) have unit tests.
Test Plan:
- cargo test -p ghostty-termio windows_args
- cargo check --target x86_64-pc-windows-gnu -p ghostty-termio
Exercises the runtime paths that had never run (details in
docs/rewrite/notes/verification-VR.md):
- IME: replay steps drive the surface's real GtkIMContext handlers with
a real preedit + attributes; preedit renders under the cursor and
commits reach the pty, incl. dead-key and compose orderings.
- Paste and OSC 52 read/write confirmation dialogs: allow, deny and
remember flows.
- Quick terminal on niri via wlr-layer-shell: positions, sizes, toggle
and autohide. Fixes a real bug: link order could put libwayland-client
ahead of libgtk4-layer-shell, silently disabling the quick terminal;
apprt-gtk now loads libwayland-client via wayland-sys dlopen.
- Flatpak host commands against a zbus mock of
org.freedesktop.Flatpak.Development under dbus-run-session: spawn,
exit status, cwd/env/fd forwarding and SIGHUP on stop, both directly
and through termio Exec (flatpak-info path seam added).
- Horizontal-scroll tab switching thresholds and reset.
tests/gtk_replay.rs runs the real binary against the session display
(skips without one).
Test Plan:
- cargo test --test gtk_replay (needs a Wayland/X11 display)
- cargo test -p ghostty-os --test flatpak_mock; -p ghostty-termio
--test flatpak_exec
Ports ZIG/src/crash/* as crates/ghostty-crash. Like Ghostty (which uses
sentry-native only to write local files), crashes are written as Sentry
envelopes (<uuid>.ghosttycrash) to $XDG_STATE_HOME/ghostty/crash:
- envelope parse/serialize (all Zig tests ported)
- panic hook plus SIGSEGV/SIGBUS/SIGILL/SIGFPE/SIGABRT handlers on an
alternate stack; the signal path is allocation-free and re-raises with
the default action so exit status and core dumps are unchanged
- thread-local crash context (main/renderer/io/read thread, surface
dimensions) set from the corresponding threads
- `sentry` cargo feature on the root binary, off by default like
upstream's -Dsentry; +crash-report lists exactly what is written
Deviation: attachments always carry "type":"attachment" (Zig's
in-memory attachments omit it and become unparseable).
Test Plan:
- cargo test -p ghostty-crash (19)
- cargo test --test crash (child panics, SIGSEGV, stack overflow and
abort each produce a valid envelope listed by +crash-report)
Ghostty's wasm code talks to JavaScript through the zig-js library
(mitchellh/zig-js, pinned in build.zig.zon). The first port invented its
own import ABI because the dependency wasn't available; now:
- ghostty-os/src/wasm/js.rs is a Rust port of zig-js's Zig side (Ref,
Value, Object get/set/call/new, global, runtime, string) using its
"zig-js" import module, function names and NaN-boxed value refs.
- web_canvas face and the atlas debug canvas make the same JS calls as
Ghostty's Zig code.
- zig-js's unmodified JS host (+ LICENSE) is vendored under
crates/ghostty-wasm/js/zig-js and drives the node test.
Test Plan:
- cargo test -p ghostty-wasm (node >= 24; asserts zig-js imports and no
leaked host values)
- RenderState stores styles sparsely (per-cell u16 style ids plus one
Style per distinct run) and skips plain cells with a single mask test
(Cell::is_plain). screen-clone render: 11.5 ms -> 4.1 ms (Zig 4.7).
row::never_extend_bg now takes a style accessor instead of a slice.
- Parser::next_with(byte, |action| ..) hands actions to a closure
instead of moving a 64-byte action array out; Parser::next remains a
wrapper over the same core (equivalence test added).
terminal-parser SGR: 538 ms -> 231 ms (Zig 354).
All Ghostty benchmarks are now at or below Zig's time; table in
docs/rewrite/notes/perf-P1.md (the parser benchmark uses next_with with
a discarding closure, which like Zig's `_ = actions` lets the optimizer
skip unused work).
Test Plan:
- cargo test --workspace
- ghostty-bench +screen-clone --mode=render / +terminal-parser
Ports main_wasm.zig as crates/ghostty-wasm (cdylib exporting the Zig
names: atlas_*, face_*, deferred_face_*, shaper_*, config_*), the
web_canvas font face and shaper (backend selected on wasm32), os/wasm
(logging, target, JS interop) and config/Wasm.zig.
C-library dependencies (freetype, harfbuzz, fontconfig, onig, gettext,
D-Bus, rustix) are target-gated. Like Zig's wasm build, link regex
search (StringMap::search_iterator) is unavailable without Oniguruma;
Collection/SharedGrid/harfbuzz are compiled out on wasm32. ghostty-os
switches from forbid to deny unsafe_code for the JS import blocks.
The JS import ABI is currently a documented handle-based interface with
a reference host (js/ghostty_host.js); aligning it with zig-js's exact
import names follows separately.
Test Plan:
- cargo build --target wasm32-unknown-unknown -p ghostty-font \
-p ghostty-config -p ghostty-terminal -p ghostty-vt -p ghostty-wasm
- cargo test -p ghostty-wasm (node runs the module against a fake canvas)
Ports ZIG/src/lib_vt.zig and terminal/c/* as crates/ghostty-vt-capi
(cdylib + staticlib + rlib, soname libghostty-vt.so) implementing the
unchanged include/ghostty/vt.h + vt/*.h ABI: OSC parser, SGR parser,
key events and key encoding, paste safety, colors, result codes - all
38 native symbols, plus the ghostty_wasm_* helpers on wasm32.
Verification:
- tests/abi.rs generates a C probe from the headers, compiled with cc,
that checks sizeof/alignof/offsetof of every struct/union, every
enumerator and #define against Rust, and links every declared symbol;
nm -D exports equal the declared functions.
- Ghostty's example/c-vt* programs compile unchanged against the Rust
library (shared and static) and produce the expected output.
- The wasm32 build runs Ghostty's wasm-key-encode/wasm-sgr example
scripts unmodified under node (upstream's wasm-sgr tag table is stale
vs sgr.h; a regenerated copy checks full output).
Test Plan:
- cargo test -p ghostty-vt-capi (22 unit + 2 ABI + 5 C + 3 wasm tests)
The GTK mouse handlers now delegate to *_impl methods taking button and
modifier state, so the real controllers and the debug input replay share
one code path. The replay hook gained mouse-move/press/release, click,
drag, scroll, resize, clipboard-set/dump, windows-dump and
window-screenshot steps (replayed presses bypass the focus-transfer
first-click rule since the replay window isn't compositor-focused).
Verified in the real app on Wayland (docs/rewrite/notes/verification-
V3.md): nvim (colors, status line, cursor shapes, alt-screen restore),
htop (rendering, mouse-click column sorting), less (alternate scroll),
tmux (splits, status bar), drag/double/triple-click selection into
PRIMARY, clipboard copy, context menu, scrollback and reflow on resize,
CJK/emoji/ZWJ/nerd-font widths, kitty graphics images and the unsafe
paste confirmation dialog. No product bugs were found.
Test Plan:
- cargo test -p ghostty-apprt-gtk (incl. parse_mouse_steps)
Addresses the partial ports listed in
docs/rewrite/notes/review-completeness-codex.md (details in
docs/rewrite/notes/gaps-X2.md):
- Flatpak: the exit watcher no longer consumes the host command; a
shared FlatpakSignalHandle lets closing a surface still SIGHUP the
host process group.
- Child environment is byte-preserving end to end (ghostty_os::EnvMap
of OsStrings) and Snap paths are filtered like filterSnapPaths.
- argv handling no longer panics on non-UTF-8 arguments.
- URI percent-decoding keeps raw bytes; OSC 7 pwd is passed through
without lossy conversion.
- Keybinding comparison/hashing uses full Unicode case folding from a
table generated from CaseFolding.txt (Unicode 17.0.0).
- Link regexes set Oniguruma's whole-search retry limit through the new
minimal ghostty-onig crate (one SAFETY-commented FFI call).
- OSC 9 NUL-capacity check ordering matches Zig.
- Wayland registry binds/clears globals advertised after startup.
- Custom shaders may pass sampler2D to helper functions (naga adapter).
- +list-themes preview renders OSC 8 links, styled underlines and
follows color-scheme reports.
Also includes the inspector's integration edits in shared files
(renderer state hook, termio VT recording, core/apprt-gtk wiring), X1's
config/input/cli additions for completion generation, and a fix for a
race in the termio backpressure test (it wrote before `stty raw`
applied, so the cooked line discipline dropped bytes past MAX_CANON).
Test Plan:
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
Ports ZIG/src/inspector (the Dear ImGui terminal inspector) as the
ghostty-inspector crate using dear-imgui-rs + dear-imgui-glow (imgui-rs
lacks a safe docking API): screen, modes, keyboard events, terminal IO
/ VT sequence log with filtering, cell inspector with picking, page
list, renderer and size/font info, with Ghostty's docking layout. The
crate denies unsafe except a single dock.rs module wrapping DockBuilder.
GTK: imgui_widget, inspector_widget and inspector_window classes with
their blueprints replace the former no-op; ctrl+shift+i toggles the
inspector window.
Core: activate/deactivate hooks, key event and mouse recording, and VT
stream recording in termio while an inspector is active, as in Zig;
overlay features reach the renderer through an InspectorHook on the
render state. The debug input replay hook gained inspector-screenshot/
click/scroll steps used to verify all tabs in the real app.
Deviations: font size scales with the display scale instead of Zig's
fixed 16*2; pop-out dock splits apply one frame later; DCS/APC
descriptions are approximated.
Test Plan:
- cargo test -p ghostty-inspector (15 incl. headless full-UI draw)
- cargo test -p ghostty-core --test e2e_inspector (4)
Ports Ghostty's build-data helpers (main_build_data.zig, src/extra/*,
build/mdgen) as the ghostty-build-data binary: bash/zsh/fish
completions, Vim syntax/ftdetect/ftplugin/compiler, Sublime syntax (also
used by bat), terminfo source and ghostty(1)/ghostty(5) markdown. With
the version set to the installed 1.3.1-arch2, all generated files are
byte-identical to the installed Ghostty's.
- `just docs` renders man pages and HTML with pandoc.
- po/: Ghostty's 29 translation catalogs; `just locales` compiles them
into the com.mitchellh.ghostty gettext domain.
- `just install PREFIX FLATPAK SYSTEM_PACKAGE` installs everything incl.
terminfo text/termcap outputs and mirrors GhosttyResources.zig install
modes (Flatpak D-Bus template without systemd; lib/systemd/user for
system packages).
- Build metadata (version, tip/stable channel, commit, build mode) is
derived at build time like build_config.zig; GTK/libadwaita
compile-time versions come from pkg-config instead of constants.
Test Plan:
- cargo run -p ghostty-build-data -- +bash | diff - \
/usr/share/bash-completion/completions/ghostty (same for zsh/fish/vim)
- just install /tmp/prefix
Adds crates/ghostty-core/tests/e2e_*.rs: 81 tests that drive the real
core Surface, termio, pty and child processes through a fake runtime
(recording apprt actions, in-memory clipboard) with a headless renderer
(ghostty-renderer/src/headless.rs). They cover keys (legacy, DECCKM,
kitty, modifyOtherKeys), keybinding actions and sequences, mouse
selection/reporting/scrolling/links, clipboard incl. OSC 52 and paste
safety, resize, focus, titles/pwd/bell/notifications/progress, child
exit, and IME preedit.
Fixes for issues found by the tests and by the Codex audit
(docs/rewrite/notes/review-core-codex.md, all 9 items):
- replacing a selection with copy-on-select panicked (stale tracked
handles); global new_window no longer inherits a parent; the child
environment uses the runtime's env wholesale so GTK's removals stick;
Flatpak host resources path; locale recovery (ensureLocale) in
apprt-gtk before GTK init and for CLI actions; failed screen-file
opens propagate errors; OSC 52 base64 rules, CSI/ESC binding length
limits and GHOSTTY_LOG parsing match Zig.
- Also includes V2's termio cleanups (tmux viewer wiring in the stream
handler, Pty slave semantics docs, shared cgroup wait loop).
apprt-gtk gains a debug input replay hook (GHOSTTY_DEBUG_INPUT_SCRIPT)
exercising the real GTK key path. With it, the real app was verified on
Wayland: typing and output, new tab, splits, select-all/copy/paste and
font size all work (docs/rewrite/notes/verification-V1.md). Not yet
exercised at GTK level: mouse, real IM-context IME, clipboard dialogs.
Test Plan:
- cargo test --workspace (2983 passed)
- cargo test -p ghostty-core --tests (81 e2e tests)
screen-clone was 2.6x slower than Zig. The main cost was in
PageList::clone_range: it created a throwaway page, recycled it into the
pool and Page::reinit then memset the entire page again, faulting in
every cell. Untouched pages now go to a clean_pool that create_node
reuses without re-zeroing. Page::init allocates cells with
bytemuck::allocation::try_zeroed_vec (Cell derives Zeroable), getting
lazily-zeroed memory from the allocator without unsafe code, and
clone_partial_row_from bulk-copies plain-cell runs in rows with managed
memory. screen-clone clone: 78 ms -> ~28 ms (Zig ~27.8 ms).
osc::Parser::next_slice appends payload bytes in bulk while behaving
exactly like per-byte next() (2048 limit, overflow), verified by a
property test; the osc-parser bench uses it (54.5 -> ~32 ms, Zig ~28).
Still slower: screen-clone render (~2.4x), dominated by per-row style
vectors in RenderState::update.
Test Plan:
- cargo test --workspace (no failures)
- ghostty-bench +screen-clone / +osc-parser with --profile production
Cleanup pass over items collected in docs/rewrite/INTEGRATION_TODO.md:
- OSC 133 printf-q / percent decoders live once in
ghostty_vt::string_encoding; ghostty-os re-exports them.
- CursorStyle and clipboard codepoint map entries have one definition
(ghostty-terminal); ghostty-config now depends on ghostty-terminal.
- ActionKey::docs() trailing blank lines fixed at the source; cli's
workaround removed (+list-actions --docs still byte-identical).
- x11_color exposes names in original case; cli no longer re-parses
rgb.txt.
- One cgroup scope wait loop (ghostty_os::cgroup::wait_for_scope).
- Flatpak passwd lookup implemented in ghostty-os via a local pty.
- +version shows the rustc version captured at build time.
Resources: dev builds find <workspace>/resources automatically (keeping
Ghostty's sentinel-file detection and GHOSTTY_RESOURCES_DIR);
scripts/gen-terminfo.sh (just terminfo) regenerates the compiled
terminfo; `just install [PREFIX]` installs binary, share/ghostty,
terminfo, desktop/D-Bus/systemd/metainfo files and icons.
Test Plan:
- cargo test for vt, os, config, input, cli
- diff `+list-keybinds`, `+list-actions --docs`, `+show-config --default`
against /usr/bin/ghostty
Adds crates/ghostty-bench, a port of ZIG/src/benchmark and src/synthetic:
the ghostty-bench binary (terminal-stream, terminal-parser,
codepoint-width, grapheme-break, is-symbol, osc-parser, screen-clone
with Zig's CLI) and ghostty-synthetic data generators (+ascii, +utf8,
+osc, plus a Rust-only +sgr mode).
Measured against Ghostty's own ghostty-bench built with Zig 0.15.2
(ReleaseFast) vs --profile production, the hot paths were optimized
without behaviour changes:
- Terminal::print single-lookup fast path for width-1 chars mid-line
- page grapheme allocator: bitmap first-fit instead of a linear scan
(was 38% of utf8 stream time; randomized equivalence test added)
- plain cells skip per-cell work in clear_cells and row cloning
- ASCII fast path + strict hand-written UTF-8 decoder (exhaustive
equivalence test against std)
- parser/OSC parser split into inlined fast and state-change paths
- RenderState allocates grapheme vectors only for grapheme rows
- Page::assert_integrity no-op stub so the production profile builds
terminal-stream is now at parity (ascii 1.08x, utf8 0.97x, SGR 1.04x of
Zig's time). Still slower: screen-clone (~2.6x, zero-filling fresh
cell Vecs vs Zig's lazily-zeroed mmap), osc-parser (1.9x), and the raw
parser on SGR data (1.5x). Full table in docs/rewrite/notes/perf-P1.md.
Test Plan:
- cargo test --workspace (no failures)
- cargo run --profile production -p ghostty-bench -- +terminal-stream
--data=<file> and compare with Zig's ghostty-bench
This is the integration step that turns the ported crates into a working
terminal: `cargo run` now opens a GTK window running the user's shell.
ghostty-core ports App.zig, Surface.zig (split into keyboard, mouse,
binding, clipboard and config submodules), surface_mouse.zig and
global.zig, and implements the runtime traits. perform_binding_action
handles every binding action.
Cross-crate integration:
- The core<->runtime traits (CoreApp, CoreSurface, RtApp, RtSurface,
Waker) move from apprt-gtk into ghostty_apprt::runtime_api so the core
stays runtime-agnostic; Scrollbar/RendererHealth stand-ins are replaced
by the real terminal/renderer types.
- termio now uses ghostty_renderer::state::{State, SharedState}; the
renderer calls kitty_update; image-storage-limit is applied at init
and on config change.
- The search thread locks the terminal through a TerminalLock trait so
it can share the render state mutex; termio's Wakeup gained a hook to
wake the renderer thread.
- apprt-gtk: GL proc addresses are resolved through libepoxy's
epoxy_glFoo pointer variables (plain glFoo symbols resolved to null),
default DPI fixed to 96, libadwaita version read without GTK init so
--version works headless.
The root binary dispatches +actions to ghostty-cli (list-fonts,
show-face and new-window are now wired) and otherwise runs the GTK app
with the real core.
Verified at runtime on Wayland and X11: shell prompt and colored output
render, child exit closes the window cleanly. Not yet verified: keyboard
and mouse input, clipboard, IME, tabs and splits (no key injection was
possible in this environment). GHOSTTY_DEBUG_SCREENSHOT=<png> dumps the
renderer's last frame for headless checks.
Test Plan:
- cargo test --workspace (2890 passed)
- cargo clippy --workspace --all-targets -- -D warnings
- GSETTINGS_BACKEND=memory GHOSTTY_RESOURCES_DIR=/usr/share/ghostty \
cargo run
Ports renderer/{generic,cell,row,link,State,Overlay,image,Thread}.zig:
- generic.rs builds GPU cell buffers from terminal RenderState each
frame: backgrounds, shaped text runs with glyph atlases and nerd font
constraints, all cursor styles, decorations via sprites, selection and
search colors, min-contrast, bold/faint/blink handling, preedit,
padding extension, background image, custom shader uniforms, link
hover underlines, scrollbar and health reporting.
- The renderer thread updates CPU-side state only and asks the host to
redraw; the app runtime calls draw_frame from the GLArea render signal
(the GL context lives on the GTK thread, as in Ghostty).
- ghostty_renderer::state::{State, SharedState} is the canonical shared
renderer state (termio's interim copy will switch to it).
Deviations: overlay uses a direct RGBA rasterizer instead of z2d; bg
images decode with png/jpeg-decoder instead of wuffs; zero-length link
matches advance by one char (Zig would loop forever).
Kitty image rendering is implemented in image::State but not yet called
from generic::update_kitty (raced with the terminal-side wiring).
Test Plan:
- cargo test -p ghostty-renderer (69 unit + 9 headless EGL tests that
render a Terminal through the full pipeline and check pixels)
Ports the remainder of ZIG/src/termio: Options, backend, message,
mailbox, Termio, Thread, Exec and stream_handler.
Threading model (replacing libxev): the IO thread owns Termio and runs a
single poll(2) loop over the mailbox eventfd, a stop eventfd, the child
pidfd and pty POLLOUT, driving Ghostty's timers (25 ms resize
coalescing, 1 s synchronized-output, 15 ms selection scroll, 200 ms
termios polling). A separate pty read thread locks the shared renderer
state and feeds the terminal. Renderer and surface interaction go
through RendererMailbox/SurfaceMailbox traits.
The stream handler answers all queries (DA, DSR, XTVERSION, DECRQM,
OSC color queries, XTGETTCAP, DECRQSS, ...) and forwards titles, pwd,
OSC 52, notifications, progress and bell as surface messages. Zig
unlocks the renderer mutex when a mailbox is full; here overflow goes to
an ordered outbox flushed after the locks drop.
IO1's local stand-ins are replaced with the real config types.
Open: RendererState lives in termio for now (renderer State.zig is
being ported); kitty graphics replies and tmux viewer are not hooked up;
wait-after-command lives in Surface (core); Flatpak stop path needs a
ghostty-os change.
Test Plan:
- cargo test -p ghostty-termio (102 unit + 21 end-to-end tests on a
real pty, incl. backpressure, DA1 replies, resize coalescing, exits)
Integration pass over the terminal core (Codex/gpt-6-astra, reviewed):
- Screen now owns the real kitty ImageStorage; new/reset/teardown,
erase-display deletes and alternate-screen limit inheritance hook in
where Zig does, and Terminal implements ExecTerminal so kitty APC
commands execute against it. Exec tests use a real Terminal.
- The PageList gains the APIs Screen/Terminal needed (pin iterators,
cross-page row/partial-row clone, string allocator probing, dedup
before allocating hyperlinks, Top viewport fixup after erase, append_
grapheme no longer marking rows dirty), and the Screen/Terminal
workarounds for their absence are removed so the code mirrors Zig.
Public signatures are unchanged; downstream crates build as before.
Test Plan:
- cargo test -p ghostty-terminal (1252 passed, 0 ignored)
- cargo clippy -p ghostty-terminal --all-targets -- -D warnings
Ports ZIG/src/apprt/gtk into ghostty-apprt-gtk: every GObject class
(application, window, tab, split tree, surface + scrolled window,
child-exited banner, search/key-state/resize overlays, command palette,
global shortcuts, all dialogs, config wrapper) as glib subclasses with
the same GType names, properties, signals and template children; GDK
key translation; X11 and Wayland window-protocol helpers (blur, CSD,
quick terminal via gtk4-layer-shell); single-instance D-Bus IPC;
gsettings; cgroup scope creation.
build.rs compiles Ghostty's blueprints with blueprint-compiler and
bundles UI, CSS and icons into a gresource, as Ghostty's build does.
The core is not ported yet, so the crate defines the boundary it needs
in src/core.rs (CoreApp, CoreSurface, RtApp, RtSurface, Waker); the
spec is in docs/rewrite/notes/ghostty-apprt-gtk.md. ghostty-core will
implement these traits (the crate no longer depends on core to avoid a
cycle). examples/demo.rs runs the app with a dummy core that clears the
GLArea; it launches on Wayland without GTK criticals.
Stubs/open items: toggle_visibility, float_window, secure_input and
close_all_windows return false; inspector is a no-op; X11/Wayland
protocol code is untested against real compositors; gtk4-rs doesn't
expose the GLArea framebuffer id, so the renderer must query it.
Also registers ghostty-apprt and ghostty-cli in workspace.dependencies.
Test Plan:
- cargo test -p ghostty-apprt-gtk (36 tests)
- DEMO_QUIT_AFTER_MS=3000 cargo run -p ghostty-apprt-gtk --example demo
Ports ZIG/src/terminal/kitty/graphics_*.zig:
- image loading for direct, file, temp-file and shared-memory
transmissions (rustix::shm, no unsafe), chunking, zlib and PNG decode
- image storage with placements (incl. virtual) tracked by PageList pins,
all delete modes, byte-limit eviction and dirty tracking
- unicode placeholder decoding and placement iteration
- command execution, generic over an ExecTerminal trait
Deviations: storage methods take the PageList explicitly; evicted or
replaced placements now release their tracked pins (Zig leaks them);
file transmissions with S= truncate per the kitty spec. Zig quirks kept
for parity: delete-range matches all placements, eviction stops only
after freeing strictly more than requested, set_limit(0) resets.
Not yet wired: Screen still holds the KittyImages placeholder, so
Terminal does not implement ExecTerminal; integration steps are in
docs/rewrite/notes/ghostty-terminal-kitty.md.
Test Plan:
- cargo test -p ghostty-terminal (66 kitty tests; all Zig tests ported)
ddidderr