From ad31b13f91e40b40d75222923ac48f6682476b0c Mon Sep 17 00:00:00 2001
From: Ankit Meel <ankitjmeel@gmail.com>
Date: Sat, 27 Mar 2021 01:08:51 +0530
Subject: [PATCH] macOS/bpy: add support for OpenMP

Changes made:
* Add OpenMP linker flags.
* Copy the libomp.dylib to `2.93/lib/libomp.dylib`.
* Change the `LC_LOAD_DYLIB` item such that
  the lib is found at `bpy.so/../../Resources/2.93/lib/libomp.dylib`.
Installation is done by D10664.

Reviewed By: #platform_macos, brecht
Maniphest Tasks: T86579
Differential Revision: https://developer.blender.org/D10657
---
 CMakeLists.txt                |  1 +
 source/creator/CMakeLists.txt | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2743d2d334c..4d224eaf46c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1235,6 +1235,7 @@ if(WITH_OPENMP)
       string(APPEND CMAKE_C_FLAGS " ${OpenMP_C_FLAGS}")
       string(APPEND CMAKE_CXX_FLAGS " ${OpenMP_CXX_FLAGS}")
       string(APPEND CMAKE_EXE_LINKER_FLAGS " ${OpenMP_LINKER_FLAGS}")
+      string(APPEND CMAKE_MODULE_LINKER_FLAGS " ${OpenMP_LINKER_FLAGS}")
     else()
       # Typically avoid adding flags as defines but we can't
       # pass OpenMP flags to the linker for static builds, meaning
diff --git a/source/creator/CMakeLists.txt b/source/creator/CMakeLists.txt
index c7b940d0012..07bc1d5d83d 100644
--- a/source/creator/CMakeLists.txt
+++ b/source/creator/CMakeLists.txt
@@ -1005,6 +1005,24 @@ elseif(APPLE)
       FILES ${LIBDIR}/openmp/lib/libomp.dylib
       DESTINATION Blender.app/Contents/Resources/lib
     )
+    if(WITH_PYTHON_MODULE)
+      # Move the dylib in a Blender version folder to keep the corresponding OpenMP version.
+      # Also for easy copying of a single folder, `TARGETDIR_VER` to site-packages
+      # during installation.
+      install(
+        DIRECTORY   ${CMAKE_BINARY_DIR}/Resources/lib
+        DESTINATION ${TARGETDIR_VER}
+      )
+      add_custom_command(TARGET blender POST_BUILD
+        # The old `LC_LOAD_DYLIB` is the `LC_ID_DYLIB` of the LIBDIR OpenMP dylib.
+        # Change it to support multiple rpaths.
+        COMMAND xcrun install_name_tool -change "@executable_path/../Resources/lib/libomp.dylib" "@rpath/libomp.dylib" "$<TARGET_FILE:blender>"
+        # For installation into site-packages.
+        COMMAND xcrun install_name_tool -add_rpath "@loader_path/../Resources/${TARGETDIR_VER}/lib" "$<TARGET_FILE:blender>"
+        # For in-build-folder experiments.
+        COMMAND xcrun install_name_tool -add_rpath "@loader_path/${TARGETDIR_VER}/lib" "$<TARGET_FILE:blender>"
+      )
+    endif()
   endif()
 
   if(WITH_LLVM AND NOT LLVM_STATIC)