FindBoost 查找Boost的inlude目录和库

查找Boost的inlude目录和库

用如下形式通过调用find_package使用这个模块

find_package( Boost [version][EXACT]   #Minimum or EXACT version e.g. 1.36.0  [REQUIRED]       #Fail with error if Boost is not found  [COMPONENTS <libs>...]     #Boost libraries by their canonical name  )       #e.g. "date_time" for "libboost_date_time"

该模块查找头文件和要求的组件库，或者一个通过“BoostCMake”构建提供的CMake包配置文件。对于后者情形，跳过下面的“BoostCMake”段落，对于前者，用变量报告这个结果:

Boost_FOUND - True if headers and requested libraries were found Boost_INCLUDE_DIRS       - Boost include directories Boost_LIBRARY_DIRS      - Link directories for Boost libraries Boost_LIBRARIES   - Boost component libraries to be linked Boost_<C>_FOUND       - True if component <C> was found (<C> is upper-case) Boost_<C>_LIBRARY       - Libraries to link for component <C> (may include target_link_libraries debug/optimized keywords) Boost_VERSION     - BOOST_VERSION value from boost/version.hpp Boost_LIB_VERSION      - Version string appended to library filenames Boost_MAJOR_VERSION       - Boost major version number (X in X.y.z) Boost_MINOR_VERSION       - Boost minor version number (Y in x.Y.z) Boost_SUBMINOR_VERSION          - Boost subminor version number (Z in x.y.Z) Boost_LIB_DIAGNOSTIC_DEFINITIONS (Windows)                         -Pass to add_definitions() to have diagnostic information about Boost's automatic linking displayed during compilation

该模块从这些变量中读取关于搜索位置的提示:

BOOST_ROOT - Preferred installation prefix 首选安装前缀  (or BOOSTROOT) BOOST_INCLUDEDIR     - Preferred include directory e.g. <prefix>/include BOOST_LIBRARYDIR    - Preferred library directory e.g. <prefix>/lib Boost_NO_SYSTEM_PATHS         - Set to ON to disable searching in locations not specified by these hint variables. Default is OFF. Boost_ADDITIONAL_VERSIONS     -List of Boost versions not known to this module (Boost installlocations may contain the version)

并在CMake的cache记录中持续（persistently）存储结果:

Boost_INCLUDE_DIR      - Directory containing Boost headers Boost_LIBRARY_DIR_RELEASE     - Directory containing release Boost libraries Boost_LIBRARY_DIR_DEBUG      - Directory containing debug Boost libraries Boost_<C>_LIBRARY_DEBUG      - Component <C> library debug variant Boost_<C>_LIBRARY_RELEASE     - Component <C> library release variant

用户可以设置这些提示或结果作为cache记录。工程项目不应直接读取这些这些记录，但可替代的是，可以使用以上结果变量。注意一些提示（hints）以大写的“BOOST”开始。如果它们没有被指定为CMake变量或者cache记录，可以指定这些变量为环境变量。

该模块首先用上面的提示变量（不包括BOOST_LIBRARYDIR）搜索Boost头文件，且存储结果于Boost_INCLUDE_DIR。然后，用上面的提示（不包括BOOST_INCLUDEDIRand Boost_ADDITIONAL_VERSIONS）搜索组建库，在Boost_INCLUDE_DIR附近的”lib”目录boost string find，库名配置设置如下。它保存库路径在Boost_LIBRARY_DIR_DEBUG和Boost_LIBRARY_DIR_RELEASE中boost string find，在Boost_<C>_LIBRARY_DEBUG和Boost_<C>_LIBRARY_RELEASE中单独的库位置。当在相同的构建树（不包括环境变量）中，对以前的搜索使用的设置进行改变时，该模块会弃用受以前的改变所影响的搜索结果，且再进行搜索。

Boost库开始使用用它们的文件名编码的变种。用户或者项目工程能区分这些模块，通过设置变量来寻找何种变种。:

Boost_USE_MULTITHREADED             - Set to OFF to use the non-multithreaded libraries ('mt' tag). Default is ON. Boost_USE_STATIC_LIBS             - Set to ON to force the use of the static libraries. Default is OFF. Boost_USE_STATIC_RUNTIME            - Set to ON or OFF to specify whether to use libraries linked statically to the C++ runtime ('s'tag). Default is platform dependent. Boost_USE_DEBUG_RUNTIME             - Set to ON or OFF to specify whether to use libraries linked to the MS debug C++ runtime('g'tag). Default is ON. Boost_USE_DEBUG_PYTHON             - Set to ON to use libraries compiled with a debug Python build ('y' tag). Default is OFF. Boost_USE_STLPORT             - Set to ON to use libraries compiled with STLPort('p' tag). Default is OFF. Boost_USE_STLPORT_DEPRECATED_NATIVE_IOSTREAMS   -Set to ON to use libraries compiled with STLPort deprecated "native iostreams"('n'tag). Default is OFF. Boost_COMPILER             - Set to the compiler-specific library suffix(e.g."-gcc43"). Default is auto-computed for the C++ compiler in use. Boost_THREADAPI             - Suffix for "thread" component library name,such as "pthread" or "win32". Names with and without this suffix will both be tried. Boost_NAMESPACE             - Alternate namespace used to build boost with e.g.if set to "myboost", will search for myboost_thread instead of boost_thread.

能设置来控制该模块的的别的一些变量是:

Boost_DEBUG       - Set to ON to enable debug output from FindBoost. Please enable this before filing any bug report. Boost_DETAILED_FAILURE_MSG   -Set to ON to add detailed information to the failure message even when the REQUIRED option is not given to the find_package call. Boost_REALPATH      - Set to ON to resolve symlinks for discovered libraries to assist with packaging. For example,the "system" component library may be resolved to                         "/usr/lib/libboost_system.so.1.42.0" instead of "/usr/lib/libboost_system.so". This does not affect linking and should not be enabled unless the user                                 needs this information. Boost_LIBRARY_DIR             - Default value for Boost_LIBRARY_DIR_RELEASE and Boost_LIBRARY_DIR_DEBUG.

如果我们要链接很多个静态库，可能就需要在编译静态库的时候/fd给静态库的符号重命名了。[0048]其中静态特征匹配的过程可以将脚本的静态特征与杀毒引擎的静态特征库中的已知静态特征进行匹配。当c运行时[crt]库和ms基础类mfc库链接、顺序有误是.同样也会导致lnk2005错误.主要是因为crt库对new、delete、dllmain函数使用弱外部链接方式.mfc库也包含了new、delete、dllmain函数定义.这些函数要求先链接mfc库然后再链接crt库.。

使用：

add_definitions(${Boost_LIB_DIAGNOSTIC_DEFINITIONS})

来要求Boost去报告关于自动链接请求的信息。

仅仅查找Boostheaders的例子:

find_package(Boost 1.36.0) if(Boost_FOUND)     include_directories(${Boost_INCLUDE_DIRS})     add_executable(foo foo.cc) endif()

寻找Boostheaders和一些静态库的例子:

set(Boost_USE_STATIC_LIBS ON) # only find static libs set(Boost_USE_MULTITHREADED ON) set(Boost_USE_STATIC_RUNTIME OFF) find_package(Boost 1.36.0 COMPONENTS date_time filesystem system ...) if(Boost_FOUND)     include_directories(${Boost_INCLUDE_DIRS})     add_executable(foo foo.cc)     target_link_libraries(foo ${Boost_LIBRARIES}) endif()

如果Boost使用boost-cmake项目工程来构建，它用一个find_package的配置模式为使用提供一个包配置文件。这个模块寻找称之为BoostConfig.cmakeor boost-config.cmake的包配置文件，且在cache记录“Boost_DIR”中存储结果。如果找到，加载包配置文件，这个模块没有返回进一步的动作。要详细了解，请见BoostCMake包配置的文档。

置Boost_NO_BOOST_CMAKE为ON将禁止对boost-cmake的搜索。