Note on compiling for macos 13.6

No (immediate) action required, but I came across an issue when compiling on macos 13.6 and wanted to record the fix.

The default clang version 14.0 has not implemented some of the c++20 features used. Hence, install the latest llvm version:

brew update
brew install llvm

and add to .bashrc:

export PATH="/usr/local/opt/llvm/bin:$PATH"
export LDFLAGS="-L/usr/local/opt/llvm/lib"
export CPPFLAGS="-I/usr/local/opt/llvm/include"
export CMAKE_PREFIX_PATH="/usr/local/opt/llvm"

Then change the standard library used by editing the CMakeLists.txt:

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 49e3aa6..5724a2f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,9 @@ option(BUILD_X86_64_BMI2 "Build with x86-64 bmi2 optimization" OFF)
 option(BUILD_DEBUG "Build with debug information" OFF)
 option(BUILD_NATIVE "Build with native optimizations" ON)

+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
+set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -stdlib=libc++")
+
 # Set the build type
 if(BUILD_DEBUG)
     set(CMAKE_BUILD_TYPE Debug)
@@ -30,9 +33,9 @@ endif()
 set(CMAKE_CXX_FLAGS_RELEASE "-pthread -fopenmp -O3 -fomit-frame-pointer -DNDEBUG")
 set(CMAKE_CXX_FLAGS_DEBUG "-pthread -fopenmp -O0 -DNDEBUG")

-if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libstdc++")
-endif()
+# if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+#     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libstdc++")
+# endif()

 # Conditionally add static linking flag on Windows
 if(WIN32)

and compile with the newly installed version of clang instead:

mkdir build
cd build
cmake -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ..

Hope this helps someone!

aronpetko / integral

Note on compiling for macos 13.6 #4