CMake notes

Why “file(GLOB xxx)” is evil

• It will cause inconspicuous problem during teamwork.
• A adds a new file and does not change CMakeLists.txt
• B does a git pull, and since there have been no modifications to the CMakeLists.txt, CMake isn’t run again and B causes linker errors when compiling.
• Reference: https://stackoverflow.com/questions/32411963/why-is-cmake-file-glob-evil

About find_package

• Check local modules: cmake –help-module-list

• Manual for a specific module: cmake –help-module FindCUDA

• find_package(CUDA 10.1 REQUIRED)

  • It is no longer necessary to use this module or call find_package(CUDA) for compiling CUDA code. Instead, list CUDA among the languages named in the top-level call to the project() command, or call the
    enable_language() command with CUDA.
  • However, if you want to some functions defined in FindCUDA module like cuda_select_nvcc_arch_flags(ARCH_FLAGS), you need explicitly use this module.
  • The following code will automatically pass nvidia graphic’s compute capability to nvcc.

  find_package(CUDA ${MIN_CUDA_VERSION} REQUIRED)
  
  set(CUDA_SEPARABLE_COMPILATION ON)
  cuda_select_nvcc_arch_flags(ARCH_FLAGS)
  string(REGEX MATCH "[0-9][0-9]" ARCH "${ARCH_FLAGS}")
  set(CMAKE_CUDA_ARCHITECTURES ${ARCH})

• find_package(CUDATookit 10.1 REQUIRED)

  • This module will define CUDAToolkit_INCLUDE_DIRS (normally /usr/local/cuda/include), CUDAToolkit_LIBRARY_DIR and etc.

• set_source_files_properties(${CUDA_SOURCE_FILES} PROPERTIES LANGUAGE CUDA)

  • This command should in the same CMakeLists.txt file with the add_library(xxx) command.

CMake Command

• shell command: cmake . -B build -G “Unix Makefiles”
• shell command: cmake –build build
• shell command: cmake –build build –target test
• shell command: cmake –build build –target install

Template for future referance

cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
project(projectname LANGUAGES CXX CUDA)

option(ENABLE_DEBUG_SYMBOLS "whether to build with debug symbols" OFF)
option(ENABLE_SANITY_CHECK  "whether to build with sanity cheks"  OFF)

if(ENABLE_DEBUG_SYMBOLS)
set(CMAKE_CXX_FLAGS "{CMAKE_CXX_FLAGS} -g")
endif(ENABLE_DEBUG_SYMBOLS)

if(ENABLE_SANITY_CHECK)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O0 -DNDEBUG -fsanitize=address -fno-omit-frame-pointer -Wno-unused-parameter")
else(ENABLE_SANITY_CHECK)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")
endif(ENABLE_SANITY_CHECK)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
set(MIN_CUDA_VERSION "10.0")

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")

add_subdirectory(projectname)