From e5e76b1192765fbd600ddee0b0f16fee7bfe6e38 Mon Sep 17 00:00:00 2001
From: mcbarton <150042563+mcbarton@users.noreply.github.com>
Date: Sat, 25 Nov 2023 19:37:46 +0000
Subject: [PATCH] Fixes issues that occur when building on Apple Silicon (#88)

Add .dylib option when building on MacOS
Disabled use of -march=native when on Apple Silicon
Link to CppInterOp (without this on MacOS you get undefined symbols error when building). Pick CppInterOp library file extension without hardcoding
---
 CMakeLists.txt                    |  5 +++++
 clingwrapper/setup.py             |  4 +++-
 clingwrapper/src/clingwrapper.cxx | 23 ++++++++++++++++++++++-
 python/cppyy_backend/loader.py    |  4 +++-
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4451f373..ea691ceb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required(VERSION 3.10)
 
 project(cppyy-backend)
 include(ExternalProject)
+include(CMakeSystemSpecificInformation)
 
 set(CMAKE_FIND_PACKAGE_SORT_ORDER NATURAL)
 set(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
@@ -64,4 +65,8 @@ endif()
 set_source_files_properties(clingwrapper/src/clingwrapper.cxx
   PROPERTIES COMPILE_DEFINITIONS "CPPINTEROP_DIR=\"${_interop_install_dir}\"")
 
+# Link to CppInterOp library. Without this can't build on MacOS due to undefined symbols
+target_link_libraries(cppyy-backend ${_interop_install_dir}/lib/libclangCppInterOp${CMAKE_SHARED_LIBRARY_SUFFIX})
+
+
 target_include_directories(cppyy-backend PUBLIC ${_interop_install_dir}/include)
diff --git a/clingwrapper/setup.py b/clingwrapper/setup.py
index 73acb8ba..530f4e9f 100644
--- a/clingwrapper/setup.py
+++ b/clingwrapper/setup.py
@@ -24,8 +24,10 @@
 
 if 'win32' in sys.platform:
     soext = '.dll'
-else:
+elif 'linux' in sys.platform:
     soext = '.so'
+else:
+    soext = '.dylib'
 
 #
 # platform-dependent helpers
diff --git a/clingwrapper/src/clingwrapper.cxx b/clingwrapper/src/clingwrapper.cxx
index 38c18835..a6ac2c13 100644
--- a/clingwrapper/src/clingwrapper.cxx
+++ b/clingwrapper/src/clingwrapper.cxx
@@ -171,11 +171,32 @@ class ApplicationStarter {
             Interp = existingInterp;
         }
         else {
+#ifdef __arm64__
+#ifdef __APPLE__
+            // If on apple silicon don't use -march=native
+            std::vector<const char *> InterpArgs({"-std=c++17"});
+#else
+            std::vector<const char *> InterpArgs(
+                {"-std=c++17", "-march=native"});
+#endif
+#else
             std::vector <const char *> InterpArgs({"-std=c++17", "-march=native"});
+#endif
             char *InterpArgString = getenv("CPPINTEROP_EXTRA_INTERPRETER_ARGS");
+
             if (InterpArgString)
-               push_tokens_from_string(InterpArgString, InterpArgs);
+              push_tokens_from_string(InterpArgString, InterpArgs);
+
+#ifdef __arm64__
+#ifdef __APPLE__
+            // If on apple silicon don't use -march=native
+            Interp = Cpp::CreateInterpreter({"-std=c++17"});
+#else
             Interp = Cpp::CreateInterpreter({"-std=c++17", "-march=native"});
+#endif
+#else
+            Interp = Cpp::CreateInterpreter({"-std=c++17", "-march=native"});
+#endif
         }
 
         // fill out the builtins
diff --git a/python/cppyy_backend/loader.py b/python/cppyy_backend/loader.py
index eaef7290..e0f765b6 100644
--- a/python/cppyy_backend/loader.py
+++ b/python/cppyy_backend/loader.py
@@ -19,8 +19,10 @@
 
 if 'win32' in sys.platform:
     soext = '.dll'
-else:
+elif 'linux' in sys.platform:
     soext = '.so'
+else:
+    soext = '.dylib'
 
 soabi = sysconfig.get_config_var("SOABI")
 soext2 = sysconfig.get_config_var("EXT_SUFFIX")