From cab0ccf0bd71bcdc17ee8590c0e68f4c3c2d47ee Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@cs.stanford.edu>
Date: Wed, 8 Sep 2021 19:02:38 +0900
Subject: [PATCH] [Mach-O] Add a stub for Mach-O

---
 Makefile      | 12 ++++++++----
 elf/main.cc   | 17 +++++------------
 elf/mold.h    |  3 +++
 macho/main.cc |  9 +++++++++
 macho/mold.h  |  5 +++++
 main.cc       | 14 ++++++++++++++
 6 files changed, 44 insertions(+), 16 deletions(-)
 create mode 100644 macho/main.cc
 create mode 100644 macho/mold.h
 create mode 100644 main.cc

diff --git a/Makefile b/Makefile
index 02644416..a282a479 100644
--- a/Makefile
+++ b/Makefile
@@ -17,9 +17,9 @@ CPPFLAGS = -g -pthread -std=c++20 -fPIE \
 LDFLAGS += $(EXTRA_LDFLAGS)
 LIBS = -pthread -lz -lxxhash -ldl -lm
 
-SRCS=$(wildcard elf/*.cc)
-HEADERS=$(wildcard elf/*.h)
-OBJS=$(SRCS:elf/%.cc=out/elf/%.o)
+SRCS=$(wildcard *.cc elf/*.cc macho/*.cc)
+HEADERS=$(wildcard *.h elf/*.h macho/*.h)
+OBJS=$(SRCS:%.cc=out/%.o)
 
 PREFIX ?= /usr
 DEST = $(DESTDIR)$(PREFIX)
@@ -79,13 +79,17 @@ mold: $(OBJS) $(MIMALLOC_LIB) $(TBB_LIB)
 mold-wrapper.so: elf/mold-wrapper.c Makefile
 	$(CC) -fPIC -shared -o $@ $< -ldl
 
-out/elf/%.o: elf/%.cc $(HEADERS) Makefile out/elf/.keep
+out/%.o: %.cc $(HEADERS) Makefile out/elf/.keep out/macho/.keep
 	$(CXX) $(CPPFLAGS) -c -o $@ $<
 
 out/elf/.keep:
 	mkdir -p out/elf
 	touch $@
 
+out/macho/.keep:
+	mkdir -p out/macho
+	touch $@
+
 $(MIMALLOC_LIB):
 	mkdir -p out/mimalloc
 	(cd out/mimalloc; CFLAGS=-DMI_USE_ENVIRON=0 cmake -G'Unix Makefiles' ../../third-party/mimalloc)
diff --git a/elf/main.cc b/elf/main.cc
index 725731bd..9a594eb5 100644
--- a/elf/main.cc
+++ b/elf/main.cc
@@ -323,7 +323,7 @@ static void show_stats(Context<E> &ctx) {
 }
 
 template <typename E>
-int do_main(int argc, char **argv) {
+int elf_main(int argc, char **argv) {
   Context<E> ctx;
 
   // Process -run option first. process_run_subcommand() does not return.
@@ -340,9 +340,9 @@ int do_main(int argc, char **argv) {
   if (ctx.arg.emulation != E::e_machine) {
     switch (ctx.arg.emulation) {
     case EM_386:
-      return do_main<I386>(argc, argv);
+      return elf_main<I386>(argc, argv);
     case EM_AARCH64:
-      return do_main<AARCH64>(argc, argv);
+      return elf_main<AARCH64>(argc, argv);
     }
     unreachable(ctx);
   }
@@ -673,18 +673,11 @@ int do_main(int argc, char **argv) {
 
 #define INSTANTIATE(E)                                                  \
   template void read_file(Context<E> &, MemoryMappedFile<E> *);         \
-  template std::string_view save_string(Context<E> &, const std::string &)
+  template std::string_view save_string(Context<E> &, const std::string &); \
+  template int elf_main<E>(int, char **);
 
 INSTANTIATE(X86_64);
 INSTANTIATE(I386);
 INSTANTIATE(AARCH64);
 
 } // namespace mold::elf
-
-int main(int argc, char **argv) {
-  std::string_view cmd = mold::elf::path_filename(argv[0]);
-  if (cmd == "ld" || cmd == "mold" || cmd == "ld.mold")
-    return mold::elf::do_main<mold::elf::X86_64>(argc, argv);
-  std::cerr << "mold: unknown command: " << argv[0] << "\n";
-  exit(1);
-}
diff --git a/elf/mold.h b/elf/mold.h
index efee91f6..edc79a06 100644
--- a/elf/mold.h
+++ b/elf/mold.h
@@ -1671,6 +1671,9 @@ std::regex glob_to_regex(std::string_view pat);
 std::string errno_string();
 std::string get_version_string();
 
+template <typename E>
+int elf_main(int argc, char **argv);
+
 //
 // Error output
 //
diff --git a/macho/main.cc b/macho/main.cc
new file mode 100644
index 00000000..d17ec932
--- /dev/null
+++ b/macho/main.cc
@@ -0,0 +1,9 @@
+#include "mold.h"
+
+namespace mold::macho {
+
+int macho_main(int argc, char **argv) {
+  return 0;
+}
+
+}
diff --git a/macho/mold.h b/macho/mold.h
new file mode 100644
index 00000000..9f7154cf
--- /dev/null
+++ b/macho/mold.h
@@ -0,0 +1,5 @@
+namespace mold::macho {
+
+int macho_main(int argc, char **argv);
+
+} // namespace mold::macho
diff --git a/main.cc b/main.cc
new file mode 100644
index 00000000..6c00c724
--- /dev/null
+++ b/main.cc
@@ -0,0 +1,14 @@
+#include "elf/mold.h"
+#include "macho/mold.h"
+
+int main(int argc, char **argv) {
+  std::string_view cmd = mold::elf::path_filename(argv[0]);
+
+  if (cmd == "ld" || cmd == "mold" || cmd == "ld.mold")
+    return mold::elf::elf_main<mold::elf::X86_64>(argc, argv);
+  if (cmd == "ld64" || cmd == "ld64.mold")
+    return mold::macho::macho_main(argc, argv);
+
+  std::cerr << "mold: unknown command: " << argv[0] << "\n";
+  exit(1);
+}