OpenHarmony开发——CMake方式组织编译的库移植

   set(CMAKE_CROSSCOMPILING TRUE)
   set(CMAKE_SYSTEM_NAME Generic)
   set(CMAKE_CXX_COMPILER_ID Clang)
   set(CMAKE_TOOLCHAIN_PREFIX llvm-)
   #指定c编译工具（确保工具链所在路径已经添加到了PATH环境变量中）和编译标志，使用clang编译时标志中必须指定--target，否则无法交叉编译。
   set(CMAKE_C_COMPILER clang)
   set(CMAKE_C_FLAGS "--target=arm-liteos -D__clang__ -march=armv7-a -w -mfloat-abi=softfp -mcpu=cortex-a7 -mfpu=neon-vfpv4")
   #指定c++编译工具（确保工具链所在路径已经添加到了PATH环境变量中）和编译标志，必须指定--target，否则无法交叉编译。
   set(CMAKE_CXX_COMPILER clang++) 
   set(CMAKE_CXX_FLAGS "--target=arm-liteos -D__clang__ -march=armv7-a -w -mfloat-abi=softfp -mcpu=cortex-a7 -mfpu=neon-vfpv4")
   #指定链接工具和链接标志，必须指定--target和--sysroot，其中OHOS_ROOT_PATH可通过cmake命令后缀参数来指定。
   set(MY_LINK_FLAGS "--target=arm-liteos --sysroot=${OHOS_SYSROOT_PATH}")
   set(CMAKE_LINKER clang)
   set(CMAKE_CXX_LINKER clang++)
   set(CMAKE_C_LINKER clang)
   set(CMAKE_C_LINK_EXECUTABLE
       "${CMAKE_C_LINKER} ${MY_LINK_FLAGS} <FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
   set(CMAKE_CXX_LINK_EXECUTABLE
       "${CMAKE_CXX_LINKER} ${MY_LINK_FLAGS} <FLAGS> <LINK_FLAGS> <OBJECTS> -o <TARGET> <LINK_LIBRARIES>")
   #指定链接库的查找路径。
   set(CMAKE_SYSROOT ${OHOS_SYSROOT_PATH})

   mkdir build && cd build
   cmake .. -DBUILD_TESTING=ON -DOHOS_SYSROOT_PATH="..."
   make -j

     cd nfs
     ./cctest --list

     test-bignum/Assign<
     test-bignum/ShiftLeft<
     test-bignum/AddUInt64<
     test-bignum/AddBignum<
     test-bignum/SubtractBignum<
     test-bignum/MultiplyUInt32<
     test-bignum/MultiplyUInt64<
     test-bignum/MultiplyPowerOfTen<
     test-bignum/DivideModuloIntBignum<
     test-bignum/Compare<
     test-bignum/PlusCompare<
     test-bignum/Square<
     test-bignum/AssignPowerUInt16<
     test-bignum-dtoa/BignumDtoaVariousDoubles<
     test-bignum-dtoa/BignumDtoaShortestVariousFloats<
     test-bignum-dtoa/BignumDtoaGayShortest<
     test-bignum-dtoa/BignumDtoaGayShortestSingle<
     test-bignum-dtoa/BignumDtoaGayFixed<
     test-bignum-dtoa/BignumDtoaGayPrecision<
     test-conversions/DoubleToShortest<
     test-conversions/DoubleToShortestSingle<
     ...

     ./cctest test-bignum

     Ran 13 tests.

     import("config.gni")
     group("double-conversion") {
         if (ohos_build_thirdparty_migrated_from_fuchisa == true) {
             deps = [":make"]
         }
     }
     if (ohos_build_thirdparty_migrated_from_fuchisa == true) {
         action("make") {
             script = "//third_party/double-conversion/build_thirdparty.py"
             outputs = ["$root_out_dir/log_dc.txt"]
             exec_path = rebase_path(rebase_path("./build", ohos_third_party_dir))
             command = "rm * .* -rf && $CMAKE_TOOLS_PATH/cmake .. $CMAKE_FLAG $CMAKE_TOOLCHAIN_FLAG && make -j"
             args = [
                 "--path=$exec_path",
                 "--command=${command}"
             ]
         }
     }

     #CMAKE_FLAG: config compile feature
     CMAKE_FLAG = "-DBUILD_TESTING=ON -DCMAKE_CXX_STANDARD=11"
   
     #toolchain：follow up-layer，depend on $ohos_build_compiler
     if (ohos_build_compiler == "clang") {
         CMAKE_TOOLCHAIN_FLAG = "-DOHOS_SYSROOT_PATH=${root_out_dir}sysroot"
     } else {
         CMAKE_TOOLCHAIN_FLAG = ""
     }
   
     #CMake tools path,no need setting if this path already joined to $PATH.
     CMAKE_TOOLS_PATH = "setting CMake tools path..."

     import os
     import sys
     from subprocess import Popen
     import argparse
     import shlex
   
     def cmd_exec(command):
         cmd = shlex.split(command)
         proc = Popen(cmd)
         proc.wait()
         ret_code = proc.returncode
         if ret_code != 0:
             raise Exception("{} failed, return code is {}".format(cmd, ret_code))
   
     def main():
         parser = argparse.ArgumentParser()
         parser.add_argument('--path', help='Build path.')
         parser.add_argument('--command', help='Build command.')
         parser.add_argument('--enable', help='enable python.', nargs='*')
         args = parser.parse_args()
   
         if args.enable:
             if args.enable[0] == 'false':
               return
   
         if args.path:
             curr_dir = os.getcwd()
             os.chdir(args.path)
             if args.command:
                 if '&&' in args.command:
                     command = args.command.split('&&')
                     for data in command:
                       cmd_exec(data)
               else:
                   cmd_exec(args.command)
           os.chdir(curr_dir)
   
      if __name__ == '__main__':
         sys.exit(main())

     declare_args() {
         ohos_build_thirdparty_migrated_from_fuchisa = true
      }

   hb build -T //third_party/double-conversion:double-conversion