Merge pull request #2441 from ghostty-org/push-sqsmtmrsswxp

macos: NSProcessInfo-based arg iterator so CLI args work

src/config/Config.zig

@@ -2290,8 +2290,12 @@ pub fn loadCliArgs(self: *Config, alloc_gpa: Allocator) !void {
     switch (builtin.os.tag) {
         .windows => {},
 
-        // Fast-path if we are non-Windows and no args, do nothing.
+        // Fast-path if we are Linux and have no args.
-        else => if (std.os.argv.len <= 1) return,
+        .linux => if (std.os.argv.len <= 1) return,
+
+        // Everything else we have to at least try because it may
+        // not use std.os.argv.
+        else => {},
     }
 
     // On Linux, we have a special case where if the executing
@@ -2360,9 +2364,13 @@ pub fn loadCliArgs(self: *Config, alloc_gpa: Allocator) !void {
         counter[i] = @field(self, field).list.items.len;
     }
 
-    // Parse the config from the CLI args
+    // Initialize our CLI iterator. The first argument is always assumed
-    var iter = try std.process.argsWithAllocator(alloc_gpa);
+    // to be the program name so we skip over that.
+    var iter = try internal_os.args.iterator(alloc_gpa);
     defer iter.deinit();
+    if (iter.next()) |argv0| log.debug("skipping argv0 value={s}", .{argv0});
+
+    // Parse the config from the CLI args
     try self.loadIter(alloc_gpa, &iter);
 
     // If we are not loading the default files, then we need to

src/os/args.zig

@@ -0,0 +1,131 @@
+const std = @import("std");
+const builtin = @import("builtin");
+const assert = std.debug.assert;
+const Allocator = std.mem.Allocator;
+const objc = @import("objc");
+const macos = @import("macos");
+
+/// Returns an iterator over the command line arguments. This may or may
+/// not allocate depending on the platform.
+///
+/// For Zig-aware readers: this is the same as std.process.argsWithAllocator
+/// but handles macOS using NSProcessInfo instead of libc argc/argv.
+pub fn iterator(allocator: Allocator) ArgIterator.InitError!ArgIterator {
+    //if (true) return try std.process.argsWithAllocator(allocator);
+    return ArgIterator.initWithAllocator(allocator);
+}
+
+/// Duck-typed to std.process.ArgIterator
+pub const ArgIterator = switch (builtin.os.tag) {
+    .macos => IteratorMacOS,
+    else => std.process.ArgIterator,
+};
+
+/// This is an ArgIterator (duck-typed for std.process.ArgIterator) for
+/// NSApplicationMain-based applications on macOS. It uses NSProcessInfo to
+/// get the command line arguments since libc argc/argv pointers are not
+/// valid.
+///
+/// I believe this should work for all macOS applications even if
+/// NSApplicationMain is not used, but I haven't tested that so I'm not
+/// sure. If/when libghostty is ever used outside of NSApplicationMain
+/// then we can revisit this.
+const IteratorMacOS = struct {
+    alloc: Allocator,
+    index: usize,
+    count: usize,
+    buf: [:0]u8,
+    args: objc.Object,
+
+    pub const InitError = Allocator.Error;
+
+    pub fn initWithAllocator(alloc: Allocator) InitError!IteratorMacOS {
+        const NSProcessInfo = objc.getClass("NSProcessInfo").?;
+        const info = NSProcessInfo.msgSend(objc.Object, objc.sel("processInfo"), .{});
+        const args = info.getProperty(objc.Object, "arguments");
+        errdefer args.release();
+
+        // Determine our maximum length so we can allocate the buffer to
+        // fit all values.
+        var max: usize = 0;
+        const count: usize = @intCast(args.getProperty(c_ulong, "count"));
+        for (0..count) |i| {
+            const nsstr = args.msgSend(
+                objc.Object,
+                objc.sel("objectAtIndex:"),
+                .{@as(c_ulong, @intCast(i))},
+            );
+
+            const maxlen: usize = @intCast(nsstr.msgSend(
+                c_ulong,
+                objc.sel("maximumLengthOfBytesUsingEncoding:"),
+                .{@as(c_ulong, 4)},
+            ));
+
+            max = @max(max, maxlen);
+        }
+
+        // Allocate our buffer. We add 1 for the null terminator.
+        const buf = try alloc.allocSentinel(u8, max, 0);
+        errdefer alloc.free(buf);
+
+        return .{
+            .alloc = alloc,
+            .index = 0,
+            .count = count,
+            .buf = buf,
+            .args = args,
+        };
+    }
+
+    pub fn deinit(self: *IteratorMacOS) void {
+        self.alloc.free(self.buf);
+
+        // Note: we don't release self.args because it is a pointer copy
+        // not a retained object.
+    }
+
+    pub fn next(self: *IteratorMacOS) ?[:0]const u8 {
+        if (self.index == self.count) return null;
+
+        // NSString. No release because not a copy.
+        const nsstr = self.args.msgSend(
+            objc.Object,
+            objc.sel("objectAtIndex:"),
+            .{@as(c_ulong, @intCast(self.index))},
+        );
+        self.index += 1;
+
+        // Convert to string using getCString. Our buffer should always
+        // be big enough because we precomputed the maximum length.
+        if (!nsstr.msgSend(
+            bool,
+            objc.sel("getCString:maxLength:encoding:"),
+            .{
+                @as([*]u8, @ptrCast(self.buf.ptr)),
+                @as(c_ulong, @intCast(self.buf.len)),
+                @as(c_ulong, 4), // NSUTF8StringEncoding
+            },
+        )) {
+            // This should never happen... if it does, we just return empty.
+            return "";
+        }
+
+        return std.mem.sliceTo(self.buf, 0);
+    }
+
+    pub fn skip(self: *IteratorMacOS) bool {
+        if (self.index == self.count) return false;
+        self.index += 1;
+        return true;
+    }
+};
+
+test "args" {
+    const testing = std.testing;
+    const alloc = testing.allocator;
+
+    var iter = try iterator(alloc);
+    defer iter.deinit();
+    try testing.expect(iter.next().?.len > 0);
+}

src/os/main.zig

@@ -15,6 +15,7 @@ const pipepkg = @import("pipe.zig");
 const resourcesdir = @import("resourcesdir.zig");
 
 // Namespaces
+pub const args = @import("args.zig");
 pub const cgroup = @import("cgroup.zig");
 pub const passwd = @import("passwd.zig");
 pub const xdg = @import("xdg.zig");