在 google-api-cpp-client 中构建专门的服务 API

Building specialized service APIs in google-api-cpp-client

我正在尝试构建专门的 Youtube API, which is included in the standard distribution of the google-api-cpp-client 库。文档指出:

If you download the C++ libraries and unzip them into the service_apis directory at the root of the source installation for this SDK then the default build scripts will automatically build them.

但是,构建脚本没有。构建包含在分布中的样本非常清楚地揭示了这一点。

Linking CXX executable ../../bin/calendar_sample
ld: library not found for -lgoogle_calendar_api

CMakeLists.txt的尾部内容如下:

add_subdirectory(src)

if (googleapis_build_samples)
  set(googleapis_build_service_apis true)  # force on
endif()
if (googleapis_build_service_apis)
  add_subdirectory(service_apis)
endif()

# Build samples after the service apis
# but keep them under src
if (googleapis_build_samples)
  add_subdirectory(src/samples)
endif()

这最终导致这个 CMakeLists.txt(在 service_apis 目录的根目录中):

file(GLOB all_valid_subdirs RELATIVE
          ${CMAKE_CURRENT_SOURCE_DIR} "*/CMakeLists.txt")

foreach(dir ${all_valid_subdirs})
    message(STATUS "path = ${dir}")
    if(${dir} MATCHES "^([^/]*)//CMakeLists.txt")
        string(REGEX REPLACE
               "^([^/]*)//CMakeLists.txt" "\1" dir_trimmed ${dir})
        add_subdirectory(${dir_trimmed})
    endif()
endforeach(dir)

我在 if 语句中放置了一个 message 输出。似乎 add_subdirectory 呼叫从未到达。 foreach 确实遍历了所有子目录。

为什么正则表达式比较失败?

其实我在做完这道题的时候发现了错误。正则表达式比较包含一个额外的正斜杠。以下正则表达式将成功包含库。

^([^/]*)/CMakeLists.txt

我会向开发者提出错误。