FIX mac openmp and add_external_project

Author: petrasvestartas

CMakeLists.txt

@@ -12,7 +12,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 # Build options
 option(ENABLE_PRECOMPILED_HEADERS "Enable precompiled headers" ON)
 option(FAST_COMPILE "Optimize for faster compilation (-O0) vs execution (-O3)" OFF)
-option(USE_OPENMP "Enable OpenMP support for parallel processing" ON)
+option(USE_OPENMP "Enable OpenMP support for parallel processing" OFF)
 
 # Apply optimization flags
 if(FAST_COMPILE)
@@ -24,50 +24,93 @@ endif()
 # ==============================================================================
 # Dependencies
 # ==============================================================================
+include(ExternalProject)
 
+# Define source directories for external dependencies
+set(EXTERNAL_DIR "${CMAKE_CURRENT_SOURCE_DIR}/external")
+set(EIGEN_INCLUDE_DIR "${EXTERNAL_DIR}/eigen")
+
+# Create a custom target for all external dependencies
+add_custom_target(external_downloads ALL)
+
+# ========================================================================
 # Setup Eigen
-set(EIGEN_INCLUDE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/external/eigen)
-find_package(Eigen3 QUIET)
-if(NOT Eigen3_FOUND)
-  # Download Eigen if not found
-  if(NOT EXISTS ${EIGEN_INCLUDE_DIR})
-    message(STATUS "Downloading Eigen...")
-    file(MAKE_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/external)
-    file(DOWNLOAD
-      https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.zip
-      ${CMAKE_CURRENT_SOURCE_DIR}/eigen.zip
-      SHOW_PROGRESS
-    )
-    execute_process(
-      COMMAND ${CMAKE_COMMAND} -E tar xf ${CMAKE_CURRENT_SOURCE_DIR}/eigen.zip
-      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/external
-    )
-    execute_process(
-      COMMAND ${CMAKE_COMMAND} -E rename 
-        ${CMAKE_CURRENT_SOURCE_DIR}/external/eigen-3.4.0 
-        ${EIGEN_INCLUDE_DIR}
-    )
-    file(REMOVE ${CMAKE_CURRENT_SOURCE_DIR}/eigen.zip)
-  endif()
-  set(EIGEN3_INCLUDE_DIRS ${EIGEN_INCLUDE_DIR})
+# ========================================================================
+if(NOT EXISTS "${EIGEN_INCLUDE_DIR}")
+  message(STATUS "Downloading Eigen...")
+  ExternalProject_Add(
+      eigen_download
+      URL https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.zip
+      SOURCE_DIR "${EIGEN_INCLUDE_DIR}"
+      CONFIGURE_COMMAND ""
+      BUILD_COMMAND ""
+      INSTALL_COMMAND ""
+      LOG_DOWNLOAD ON
+      UPDATE_COMMAND ""
+      PATCH_COMMAND ""
+      TLS_VERIFY ON
+  )
+  add_dependencies(external_downloads eigen_download)
 endif()
+set(EIGEN3_INCLUDE_DIRS "${EIGEN_INCLUDE_DIR}")
+
+# Print include directories for verification
+message(STATUS "============= Dependencies =============")
+message(STATUS "EIGEN INCLUDE DIRECTORY: ${EIGEN_INCLUDE_DIR}")
+message(STATUS "=========================================")
 
 # Find Python and nanobind
 find_package(Python 3.8 REQUIRED COMPONENTS Interpreter Development.Module)
 find_package(nanobind CONFIG REQUIRED)
 find_package(Threads REQUIRED)
 
-# Setup OpenMP
+# Setup OpenMP - Properly handle macOS and make it optional
 if(USE_OPENMP)
-  find_package(OpenMP QUIET)
-  if(OpenMP_CXX_FOUND)
-    message(STATUS "OpenMP found - enabling parallel processing")
-    add_definitions(-DSHAPEOP_OPENMP)
+  # Check what platform we're on
+  if(APPLE)
+    # On macOS, OpenMP might not be available with the default Clang
+    # Check if we have Homebrew's LLVM/Clang with OpenMP support
+    find_program(BREW NAMES brew)
+    if(BREW)
+      execute_process(
+        COMMAND ${BREW} --prefix llvm
+        OUTPUT_VARIABLE LLVM_DIR
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+      )
+      if(LLVM_DIR)
+        # Use Homebrew's LLVM for OpenMP support
+        set(OpenMP_CXX_FLAGS "-fopenmp")
+        set(OpenMP_CXX_LIB_NAMES "omp")
+        set(OpenMP_omp_LIBRARY "${LLVM_DIR}/lib/libomp.dylib")
+        message(STATUS "Using Homebrew LLVM for OpenMP support: ${LLVM_DIR}")
+        add_definitions(-DSHAPEOP_OPENMP)
+      else()
+        message(STATUS "Homebrew LLVM not found. OpenMP support disabled on macOS.")
+        set(USE_OPENMP OFF)
+      endif()
+    else()
+      message(STATUS "Homebrew not found. OpenMP support disabled on macOS.")
+      set(USE_OPENMP OFF)
+    endif()
   else()
-    message(STATUS "OpenMP not found - parallel processing disabled")
+    # For non-macOS platforms, use standard FindOpenMP
+    find_package(OpenMP QUIET)
+    if(OpenMP_CXX_FOUND)
+      message(STATUS "OpenMP found - enabling parallel processing")
+      add_definitions(-DSHAPEOP_OPENMP)
+    else()
+      message(STATUS "OpenMP not found - parallel processing disabled")
+      set(USE_OPENMP OFF)
+    endif()
   endif()
 endif()
 
+# Add include directories
+include_directories(
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  ${EIGEN3_INCLUDE_DIRS}
+)
+
 # ==============================================================================
 # ShapeOp library
 # ==============================================================================
@@ -87,16 +130,23 @@ add_library(shapeop STATIC
   ${SHAPEOP_SRC_DIR}/custom_constraints/NormalForce.cpp
 )
 
-target_include_directories(shapeop PUBLIC
-  ${CMAKE_CURRENT_SOURCE_DIR}/src
-  ${EIGEN3_INCLUDE_DIRS}
-)
+# Make shapeop depend on the external downloads
+add_dependencies(shapeop external_downloads)
 
 target_compile_options(shapeop PRIVATE -fPIC)
 target_compile_definitions(shapeop PUBLIC SHAPEOP_EXPORT)
-if(OpenMP_CXX_FOUND)
-  target_compile_options(shapeop PUBLIC ${OpenMP_CXX_FLAGS})
-  target_link_libraries(shapeop PUBLIC ${OpenMP_CXX_LIBRARIES})
+
+# Apply OpenMP flags only if enabled and available
+if(USE_OPENMP)
+  if(DEFINED OpenMP_CXX_FLAGS)
+    target_compile_options(shapeop PUBLIC ${OpenMP_CXX_FLAGS})
+    if(DEFINED OpenMP_CXX_LIBRARIES)
+      target_link_libraries(shapeop PUBLIC ${OpenMP_CXX_LIBRARIES})
+    endif()
+    if(APPLE AND DEFINED OpenMP_omp_LIBRARY)
+      target_link_libraries(shapeop PUBLIC ${OpenMP_omp_LIBRARY})
+    endif()
+  endif()
 endif()
 
 # ==============================================================================
@@ -117,26 +167,47 @@ endif()
 # Python module
 # ==============================================================================
 
-# Add the Solver Python module
-nanobind_add_module(
-  _shapeop
-  STABLE_ABI
-  NB_STATIC
-  src/shapeop.cpp
-)
+# Function to add a nanobind module with include directories
+function(add_nanobind_module module_name source_file)
+  nanobind_add_module(
+    ${module_name}
+    STABLE_ABI
+    NB_STATIC
+    ${source_file}
+  )
 
-target_include_directories(_shapeop PRIVATE
-  ${CMAKE_CURRENT_SOURCE_DIR}/src
-  ${EIGEN3_INCLUDE_DIRS}
-  ${nanobind_INCLUDE_DIRS}
-)
+  target_include_directories(${module_name} PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}/src
+    ${EIGEN3_INCLUDE_DIRS}
+    ${nanobind_INCLUDE_DIRS}
+  )
 
-target_link_libraries(_shapeop PRIVATE shapeop)
-if(ENABLE_PRECOMPILED_HEADERS)
-  target_link_libraries(_shapeop PRIVATE compas_pch)
-endif()
+  # Make module depend on the external downloads
+  add_dependencies(${module_name} external_downloads)
+
+  # Apply OpenMP flags only if enabled and available
+  if(USE_OPENMP)
+    if(DEFINED OpenMP_CXX_FLAGS)
+      target_compile_options(${module_name} PRIVATE ${OpenMP_CXX_FLAGS})
+      if(DEFINED OpenMP_CXX_LIBRARIES)
+        target_link_libraries(${module_name} PRIVATE ${OpenMP_CXX_LIBRARIES})
+      endif()
+      if(APPLE AND DEFINED OpenMP_omp_LIBRARY)
+        target_link_libraries(${module_name} PRIVATE ${OpenMP_omp_LIBRARY})
+      endif()
+    endif()
+  endif()
 
-install(TARGETS _shapeop LIBRARY DESTINATION compas_shapeop)
+  if(ENABLE_PRECOMPILED_HEADERS)
+    target_link_libraries(${module_name} PRIVATE compas_pch)
+  endif()
+
+  install(TARGETS ${module_name} LIBRARY DESTINATION compas_shapeop)
+endfunction()
+
+# Add ShapeOp module
+add_nanobind_module(_shapeop src/shapeop.cpp)
+target_link_libraries(_shapeop PRIVATE shapeop)
 
 # ==============================================================================
 # Summary
@@ -147,4 +218,7 @@ message(STATUS "Build Type: ${CMAKE_BUILD_TYPE}")
 message(STATUS "C++ Standard: C++${CMAKE_CXX_STANDARD}")
 message(STATUS "Optimization: ${FAST_COMPILE} (O0 if ON, O3 if OFF)")
 message(STATUS "Precompiled Headers: ${ENABLE_PRECOMPILED_HEADERS}")
-message(STATUS "=============================================")
+message(STATUS "OpenMP Support: ${USE_OPENMP}")
+message(STATUS "Eigen Include Dir: ${EIGEN3_INCLUDE_DIRS}")
+message(STATUS "External Dir: ${EXTERNAL_DIR}")
+message(STATUS "===============================================")