diff --git a/macho/cmdline.cc b/macho/cmdline.cc
new file mode 100644
index 00000000..e7fb848c
--- /dev/null
+++ b/macho/cmdline.cc
@@ -0,0 +1,89 @@
+#include "mold.h"
+
+#include <sstream>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <unordered_set>
+
+namespace mold::macho {
+
+static const char helpmsg[] = R"(
+Options:
+  --help                      Report usage information
+  -v                          Report version information
+  -o FILE                     Set output filename
+)";
+
+bool read_arg(Context &ctx, std::span<std::string_view> &args,
+              std::string_view &arg, std::string name) {
+  if (args[0] == name) {
+    if (args.size() == 1)
+      Fatal(ctx) << "option -" << name << ": argument missing";
+    arg = args[1];
+    args = args.subspan(2);
+    return true;
+  }
+  return false;
+}
+
+bool read_flag(std::span<std::string_view> &args, std::string name) {
+  if (args[0] == name) {
+    args = args.subspan(1);
+    return true;
+  }
+  return false;
+}
+
+void parse_nonpositional_args(Context &ctx,
+                              std::vector<std::string_view> &remaining) {
+  std::span<std::string_view> args = ctx.cmdline_args;
+  args = args.subspan(1);
+
+  bool version_shown = false;
+
+  while (!args.empty()) {
+    std::string_view arg;
+
+    auto read_arg = [&](std::string name) {
+      if (args[0] == name) {
+        if (args.size() == 1)
+          Fatal(ctx) << "option -" << name << ": argument missing";
+        arg = args[1];
+        args = args.subspan(2);
+        return true;
+      }
+      return false;
+    };
+
+    auto read_flag = [&](std::string name) {
+      if (args[0] == name) {
+        args = args.subspan(1);
+        return true;
+      }
+      return false;
+    };
+
+    if (read_flag("-help") || read_flag("--help")) {
+      SyncOut(ctx) << "Usage: " << ctx.cmdline_args[0]
+                   << " [options] file...\n" << helpmsg;
+      exit(0);
+    }
+
+    if (read_flag("-v")) {
+      SyncOut(ctx) << mold_version;
+    } else if (read_arg("-o")) {
+      ctx.arg.output = arg;
+    } else {
+      if (args[0][0] == '-')
+        Fatal(ctx) << "unknown command line option: " << args[0];
+      remaining.push_back(args[0]);
+      args = args.subspan(1);
+    }
+  }
+
+  if (ctx.arg.output.empty())
+    ctx.arg.output = "a.out";
+}
+
+} // namespace mold::macho
diff --git a/macho/main.cc b/macho/main.cc
index 7b4509ae..011a0094 100644
--- a/macho/main.cc
+++ b/macho/main.cc
@@ -69,12 +69,6 @@ static i64 assign_offsets(Context &ctx) {
 int main(int argc, char **argv) {
   Context ctx;
 
-  // Parse command line arguments
-  if (argc == 1) {
-    SyncOut(ctx) << "mold macho stub\n";
-    exit(0);
-  }
-
   if (std::string_view(argv[1]) == "-dump") {
     if (argc != 3)
       Fatal(ctx) << "usage: ld64.mold -dump <executable-name>\n";
@@ -82,29 +76,25 @@ int main(int argc, char **argv) {
     exit(0);
   }
 
-  if (std::string_view(argv[1]) == "-out") {
-    if (argc != 3)
-      Fatal(ctx) << "usage: ld64.mold -out <output-file>\n";
-    ctx.arg.output = argv[2];
+  ctx.cmdline_args = expand_response_files(ctx, argv);
+  std::vector<std::string_view> file_args;
+  parse_nonpositional_args(ctx, file_args);
 
-    create_synthetic_sections(ctx);
-    fill_symtab(ctx);
-    export_symbols(ctx);
-    ctx.load_cmd.compute_size(ctx);
-    i64 output_size = assign_offsets(ctx);
+  create_synthetic_sections(ctx);
+  fill_symtab(ctx);
+  export_symbols(ctx);
+  ctx.load_cmd.compute_size(ctx);
+  i64 output_size = assign_offsets(ctx);
 
-    ctx.output_file =
-      std::make_unique<OutputFile>(ctx, ctx.arg.output, output_size, 0777);
-    ctx.buf = ctx.output_file->buf;
+  ctx.output_file =
+    std::make_unique<OutputFile>(ctx, ctx.arg.output, output_size, 0777);
+  ctx.buf = ctx.output_file->buf;
 
-    for (OutputSegment *seg : ctx.segments)
-      seg->copy_buf(ctx);
+  for (OutputSegment *seg : ctx.segments)
+    seg->copy_buf(ctx);
 
-    ctx.output_file->close(ctx);
-    exit(0);
-  }
-
-  Fatal(ctx) << "usage: ld64.mold\n";
+  ctx.output_file->close(ctx);
+  return 0;
 }
 
 }
diff --git a/macho/mold.h b/macho/mold.h
index e7678bde..9309dff3 100644
--- a/macho/mold.h
+++ b/macho/mold.h
@@ -329,6 +329,13 @@ public:
 
 void dump_file(std::string path);
 
+//
+// cmdline.cc
+//
+
+void parse_nonpositional_args(Context &ctx,
+                              std::vector<std::string_view> &remaining);
+
 //
 // main.cc
 //
@@ -348,14 +355,20 @@ struct Context {
   struct {
     bool demangle = false;
     bool fatal_warnings = false;
+    std::string chroot;
     std::string output;
   } arg;
 
+  std::vector<std::string_view> cmdline_args;
+
   bool has_error = false;
 
   std::unique_ptr<OutputFile> output_file;
   u8 *buf;
 
+  tbb::concurrent_vector<std::unique_ptr<u8[]>> string_pool;
+  tbb::concurrent_vector<std::unique_ptr<MappedFile<Context>>> mf_pool;
+
   OutputSegment text_seg{"__TEXT", VM_PROT_READ | VM_PROT_EXECUTE, 0};
   OutputSegment data_const_seg{"__DATA_CONST", VM_PROT_READ | VM_PROT_WRITE,
                                SG_READ_ONLY};