macho: recognise -r flag and error as unimplemented

src/MachO.zig

@@ -348,6 +348,9 @@ pub fn flush(self: *MachO) !void {
 
     try self.addUndefinedGlobals();
     try self.resolveSymbols();
+
+    if (self.options.relocatable) return relocatable.flush(self);
+
     try self.resolveSyntheticSymbols();
 
     try self.convertTentativeDefinitions();
@@ -3156,11 +3159,12 @@ const macho = std.macho;
 const math = std.math;
 const mem = std.mem;
 const meta = std.meta;
-const thunks = @import("MachO/thunks.zig");
-const trace = @import("tracy.zig").trace;
+const relocatable = @import("MachO/relocatable.zig");
 const synthetic = @import("MachO/synthetic.zig");
 const state_log = std.log.scoped(.state);
 const std = @import("std");
+const thunks = @import("MachO/thunks.zig");
+const trace = @import("tracy.zig").trace;
 
 const Allocator = mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;

src/MachO/Options.zig

@@ -61,6 +61,7 @@ const usage =
     \\-platform_version [platform] [min_version] [sdk_version]
     \\                                   Sets the platform, oldest supported version of that platform and 
     \\                                   the SDK it was built against
+    \\-r                                 Create a relocatable object file
     \\-reexport-l[name]                  Link against library and re-export it for the clients
     \\  -reexport_library [name]
     \\-rpath [path]                      Specify runtime path
@@ -91,6 +92,7 @@ const cmd = "ld64.zld";
 
 emit: Zld.Emit,
 dylib: bool = false,
+relocatable: bool = false,
 dynamic: bool = false,
 cpu_arch: ?std.Target.Cpu.Arch = null,
 platform: ?Platform = null,
@@ -238,6 +240,8 @@ pub fn parse(arena: Allocator, args: []const []const u8, ctx: anytype) !Options
             try force_undefined_symbols.put(name, {});
         } else if (p.flag1("S")) {
             opts.strip = true;
+        } else if (p.flag1("r")) {
+            opts.relocatable = true;
         } else if (p.flag1("all_load")) {
             opts.all_load = true;
         } else if (p.arg1("force_load")) |path| {

src/main.zig

@@ -112,6 +112,7 @@ pub fn main() !void {
         error.UndefinedSymbols,
         error.RelocError,
         error.ResolveFailed,
+        error.Unimplemented,
         => {
             zld.reportWarnings();
             zld.reportErrors();