cmake无法在build_command中正确运行ExternalProject_Add

Question

我只想下载一个via cmake的git存储库，并将源文件夹复制到其他地方。下面是一个最小的工作示例：

cmake_minimum_required (VERSION 2.8)
project ("myProject")
include(ExternalProject)

# Download and copy the repository
set(PROJECT_NAME_CHIBIOS "ChibiOS")
ExternalProject_Add(${PROJECT_NAME_CHIBIOS}
                    PREFIX ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME_CHIBIOS}-Download
                    GIT_REPOSITORY https://github.com/ChibiOS/ChibiOS-RT.git
                    GIT_TAG b440caa10ced9532a467e4cbb96e1b3f0b99060a
                    CONFIGURE_COMMAND ""
                    BUILD_COMMAND "${CMAKE_COMMAND} -E copy_directory <SOURCE_DIR> ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME_CHIBIOS}"
                    UPDATE_COMMAND ""
                    INSTALL_COMMAND ""
                    LOG_DOWNLOAD 1
                    LOG_UPDATE 1
                    LOG_CONFIGURE 1
                    LOG_BUILD 1
                    LOG_TEST 1
                    LOG_INSTALL 1
                  )

除了BUILD_COMMAND中的copy命令之外，所有东西都可以从框内运行。make刚刚说：

Scanning dependencies of target ChibiOS
[ 12%] Creating directories for 'ChibiOS'
[ 25%] Performing download step (git clone) for 'ChibiOS'
-- ChibiOS download command succeeded.  See also /tmp/ChibiOS-Download/src/ChibiOS-stamp/ChibiOS-download-*.log

[ 37%] No patch step for 'ChibiOS'
[ 50%] No update step for 'ChibiOS'
[ 62%] No configure step for 'ChibiOS'
[ 75%] Performing build step for 'ChibiOS'
CMake Error at /tmp/ChibiOS-Download/src/ChibiOS-stamp/ChibiOS-build.cmake:16 (message):
  Command failed: No such file or directory

  '/usr/bin/cmake -E copy_directory /tmp/ChibiOS-Download/src/ChibiOS /tmp/ChibiOS' 

但是，如果我将/usr/bin/cmake -E copy_directory /tmp/ChibiOS-Download/src/ChibiOS /tmp/ChibiOS复制到shell中，它会在之后工作。

我做错了什么？

Answer 1

对于您的BUILD_COMMAND，您已经用引号包装了整个命令，因此CMake将其视为一个参数。

您只需要删除引号就可以让CMake将其解析为一个带有4个参数的命令：

...
BUILD_COMMAND ${CMAKE_COMMAND} -E copy_directory <SOURCE_DIR> ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME_CHIBIOS}
...