From 1b46884e726ce063f183fbb119a6ac07fb7c7ba1 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Sat, 20 Sep 2025 20:47:37 -0700
Subject: [PATCH] terminal: add build option for oniguruma, which controls tmux
 cc mode

---
 src/build/GhosttyZig.zig       |  1 +
 src/terminal/build_options.zig |  9 +++++++++
 src/terminal/dcs.zig           | 34 ++++++++++++++++++++++++++--------
 src/terminal/main.zig          |  3 ++-
 4 files changed, 38 insertions(+), 9 deletions(-)

diff --git a/src/build/GhosttyZig.zig b/src/build/GhosttyZig.zig
index e3c22bc67..571428233 100644
--- a/src/build/GhosttyZig.zig
+++ b/src/build/GhosttyZig.zig
@@ -23,6 +23,7 @@ pub fn init(
     deps.unicode_tables.addModuleImport(vt);
     vt_options.addOptions(b, vt, .{
         .artifact = .lib,
+        .oniguruma = false,
         .slow_runtime_safety = switch (cfg.optimize) {
             .Debug => true,
             .ReleaseSafe,
diff --git a/src/terminal/build_options.zig b/src/terminal/build_options.zig
index 33cf7a2ef..98d9bc8fa 100644
--- a/src/terminal/build_options.zig
+++ b/src/terminal/build_options.zig
@@ -4,6 +4,10 @@ pub const Options = struct {
     /// The target artifact to build. This will gate some functionality.
     artifact: Artifact = .ghostty,
 
+    /// Whether Oniguruma regex support is available. If this isn't
+    /// available, some features will be disabled.
+    oniguruma: bool = true,
+
     /// True if we should enable the "slow" runtime safety checks. These
     /// are runtime safety checks that are slower than typical and should
     /// generally be disabled in production builds.
@@ -26,6 +30,11 @@ pub fn addOptions(
 ) void {
     const opts = b.addOptions();
     opts.addOption(Artifact, "artifact", v.artifact);
+    opts.addOption(bool, "oniguruma", v.oniguruma);
     opts.addOption(bool, "slow_runtime_safety", v.slow_runtime_safety);
+
+    // These are synthesized based on other options.
+    opts.addOption(bool, "tmux_control_mode", v.oniguruma);
+
     m.addOptions("terminal_options", opts);
 }
diff --git a/src/terminal/dcs.zig b/src/terminal/dcs.zig
index db5f95c4f..e4d0f3de2 100644
--- a/src/terminal/dcs.zig
+++ b/src/terminal/dcs.zig
@@ -1,4 +1,5 @@
 const std = @import("std");
+const build_options = @import("terminal_options");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const terminal = @import("main.zig");
@@ -51,6 +52,11 @@ pub const Handler = struct {
             0 => switch (dcs.final) {
                 // Tmux control mode
                 'p' => tmux: {
+                    if (comptime !build_options.tmux_control_mode) {
+                        log.debug("tmux control mode not enabled in build, ignoring", .{});
+                        break :tmux null;
+                    }
+
                     // Tmux control mode must start with ESC P 1000 p
                     if (dcs.params.len != 1 or dcs.params[0] != 1000) break :tmux null;
 
@@ -121,9 +127,11 @@ pub const Handler = struct {
             .ignore,
             => {},
 
-            .tmux => |*tmux| return .{
-                .tmux = (try tmux.put(byte)) orelse return null,
-            },
+            .tmux => |*tmux| if (comptime build_options.tmux_control_mode) {
+                return .{
+                    .tmux = (try tmux.put(byte)) orelse return null,
+                };
+            } else unreachable,
 
             .xtgettcap => |*list| {
                 if (list.items.len >= self.max_bytes) {
@@ -157,10 +165,10 @@ pub const Handler = struct {
             .ignore,
             => null,
 
-            .tmux => tmux: {
+            .tmux => if (comptime build_options.tmux_control_mode) tmux: {
                 self.state.deinit();
                 break :tmux .{ .tmux = .{ .exit = {} } };
-            },
+            } else unreachable,
 
             .xtgettcap => |list| xtgettcap: {
                 for (list.items, 0..) |b, i| {
@@ -203,7 +211,10 @@ pub const Command = union(enum) {
     decrqss: DECRQSS,
 
     /// Tmux control mode
-    tmux: terminal.tmux.Notification,
+    tmux: if (build_options.tmux_control_mode)
+        terminal.tmux.Notification
+    else
+        void,
 
     pub fn deinit(self: Command) void {
         switch (self) {
@@ -269,7 +280,10 @@ const State = union(enum) {
     },
 
     /// Tmux control mode: https://github.com/tmux/tmux/wiki/Control-Mode
-    tmux: terminal.tmux.Client,
+    tmux: if (build_options.tmux_control_mode)
+        terminal.tmux.Client
+    else
+        void,
 
     pub fn deinit(self: *State) void {
         switch (self.*) {
@@ -279,7 +293,9 @@ const State = union(enum) {
 
             .xtgettcap => |*v| v.deinit(),
             .decrqss => {},
-            .tmux => |*v| v.deinit(),
+            .tmux => |*v| if (comptime build_options.tmux_control_mode) {
+                v.deinit();
+            } else unreachable,
         }
     }
 };
@@ -395,6 +411,8 @@ test "DECRQSS invalid command" {
 }
 
 test "tmux enter and implicit exit" {
+    if (comptime !build_options.tmux_control_mode) return error.SkipZigTest;
+
     const testing = std.testing;
     const alloc = testing.allocator;
 
diff --git a/src/terminal/main.zig b/src/terminal/main.zig
index 74ffe6341..1fea9934e 100644
--- a/src/terminal/main.zig
+++ b/src/terminal/main.zig
@@ -1,4 +1,5 @@
 const builtin = @import("builtin");
+const build_options = @import("terminal_options");
 
 const charsets = @import("charsets.zig");
 const sanitize = @import("sanitize.zig");
@@ -20,7 +21,7 @@ pub const page = @import("page.zig");
 pub const parse_table = @import("parse_table.zig");
 pub const search = @import("search.zig");
 pub const size = @import("size.zig");
-pub const tmux = @import("tmux.zig");
+pub const tmux = if (build_options.tmux_control_mode) @import("tmux.zig") else struct {};
 pub const x11_color = @import("x11_color.zig");
 
 pub const Charset = charsets.Charset;