cmake 模板集成 Coverage 功能

[condy0919]

例如这样

if(SPBLAS_ENABLE_COVERAGE)
  include(CheckCXXCompilerFlag)
  if(CMAKE_COMPILER_IS_GNUCXX)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --coverage")
    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} --coverage")
    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --coverage")
    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} --coverage")
  else()
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fprofile-arcs -ftest-coverage -fno-elide-constructors -fprofile-instr-generate -fcoverage-mapping")
    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fprofile-arcs -ftest-coverage -fprofile-instr-generate -fcoverage-mapping")
  endif()
endif()