feat: finish ghostty pane backend integration

1 files changed, 145 insertions, 0 deletions

diff --git a/vendor/libghostty-vt/src/lib/enum.zig b/vendor/libghostty-vt/src/lib/enum.zig
new file mode 100644
index 00000000..76e05fa9
--- /dev/null
+++ b/vendor/libghostty-vt/src/lib/enum.zig
@@ -0,0 +1,145 @@
+const std = @import("std");
+const Target = @import("target.zig").Target;
+
+/// Create an enum type with the given keys that is C ABI compatible
+/// if we're targeting C, otherwise a Zig enum with smallest possible
+/// backing type.
+///
+/// In all cases, the enum keys will be created in the order given.
+/// For C ABI, this means that the order MUST NOT be changed in order
+/// to preserve ABI compatibility. You can set a key to null to
+/// remove it from the Zig enum while keeping the "hole" in the C enum
+/// to preserve ABI compatibility.
+///
+/// C detection is up to the caller, since there are multiple ways
+/// to do that. We rely on the `target` parameter to determine whether we
+/// should create a C compatible enum or a Zig enum.
+///
+/// For the Zig enum, the enum value is not guaranteed to be stable, so
+/// it shouldn't be relied for things like serialization.
+pub fn Enum(
+    target: Target,
+    keys: []const ?[:0]const u8,
+) type {
+    var fields: [keys.len]std.builtin.Type.EnumField = undefined;
+    var fields_i: usize = 0;
+    var holes: usize = 0;
+    for (keys) |key_| {
+        const key: [:0]const u8 = key_ orelse {
+            switch (target) {
+                // For Zig we don't track holes because the enum value
+                // isn't guaranteed to be stable and we want to use the
+                // smallest possible backing type.
+                .zig => {},
+
+                // For C we must track holes to preserve ABI compatibility
+                // with subsequent values.
+                .c => holes += 1,
+            }
+            continue;
+        };
+
+        fields[fields_i] = .{
+            .name = key,
+            .value = fields_i + holes,
+        };
+        fields_i += 1;
+    }
+
+    // Assigned to var so that the type name is nicer in stack traces.
+    const Result = @Type(.{ .@"enum" = .{
+        .tag_type = switch (target) {
+            .c => c_int,
+            .zig => std.math.IntFittingRange(0, fields_i - 1),
+        },
+        .fields = fields[0..fields_i],
+        .decls = &.{},
+        .is_exhaustive = true,
+    } });
+    return Result;
+}
+
+test "zig" {
+    const testing = std.testing;
+    const T = Enum(.zig, &.{ "a", "b", "c", "d" });
+    const info = @typeInfo(T).@"enum";
+    try testing.expectEqual(u2, info.tag_type);
+}
+
+test "c" {
+    const testing = std.testing;
+    const T = Enum(.c, &.{ "a", "b", "c", "d" });
+    const info = @typeInfo(T).@"enum";
+    try testing.expectEqual(c_int, info.tag_type);
+}
+
+test "abi by removing a key" {
+    const testing = std.testing;
+    // C
+    {
+        const T = Enum(.c, &.{ "a", "b", null, "d" });
+        const info = @typeInfo(T).@"enum";
+        try testing.expectEqual(c_int, info.tag_type);
+        try testing.expectEqual(3, @intFromEnum(T.d));
+    }
+
+    // Zig
+    {
+        const T = Enum(.zig, &.{ "a", "b", null, "d" });
+        const info = @typeInfo(T).@"enum";
+        try testing.expectEqual(u2, info.tag_type);
+        try testing.expectEqual(2, @intFromEnum(T.d));
+    }
+}
+
+/// Verify that for every key in enum T, there is a matching declaration in
+/// `ghostty.h` with the correct value. This should only ever be called inside a `test`
+/// because the `ghostty.h` module is only available then.
+pub fn checkGhosttyHEnum(
+    comptime T: type,
+    comptime prefix: []const u8,
+) !void {
+    const info = @typeInfo(T);
+
+    try std.testing.expect(info == .@"enum");
+    try std.testing.expect(info.@"enum".tag_type == c_int);
+    try std.testing.expect(info.@"enum".is_exhaustive == true);
+
+    @setEvalBranchQuota(100_000);
+
+    const c = @import("ghostty.h");
+
+    var set: std.EnumSet(T) = .initFull();
+
+    const enum_fields = info.@"enum".fields;
+
+    inline for (enum_fields) |field| {
+        const expected_name: *const [prefix.len + field.name.len]u8 = comptime e: {
+            var buf: [prefix.len + field.name.len]u8 = undefined;
+            @memcpy(buf[0..prefix.len], prefix);
+            for (buf[prefix.len..], field.name) |*d, s| {
+                d.* = std.ascii.toUpper(s);
+            }
+            break :e &buf;
+        };
+
+        if (@hasDecl(c, expected_name)) {
+            std.testing.expectEqual(field.value, @field(c, expected_name)) catch |e| {
+                std.log.err(@typeName(T) ++ " key " ++ field.name ++ " does not have the same backing int as " ++ expected_name, .{});
+                return e;
+            };
+
+            set.remove(@enumFromInt(field.value));
+        }
+    }
+
+    std.testing.expect(set.count() == 0) catch |e| {
+        var it = set.iterator();
+        while (it.next()) |v| {
+            var buf: [128]u8 = undefined;
+            const upper_string = std.ascii.upperString(&buf, @tagName(v));
+            std.log.err("ghostty.h is missing value for {s}{s}", .{ prefix, upper_string });
+        }
+        return e;
+    };
+}