set(CMAKE_BUILD_TYPE "Release")
if( CMAKE_BUILD_TYPE STREQUAL "Debug" )
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -g -Wall -Wno-unused-variable -pthread")
else( CMAKE_BUILD_TYPE STREQUAL "Debug" )
set(CMAKE_BUILD_TYPE "Release")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -O2 -pthread -fopenmp")
endif( CMAKE_BUILD_TYPE STREQUAL "Debug" )
message("Build Type:"${CMAKE_BUILD_TYPE} ${CMAKE_CXX_FLAGS})
【转】:https://blog.csdn.net/d_o_n_g2/article/details/76043108?utm_source=blogxgwz6