Question

我知道已经多次询问过了，但我似乎已经正确设置了所有必需的变量，并且cmake一直没有找到所需的组件。

我成功（有奋斗......）编译了boost库，他们有这个文件结构：

C:\boost_1_57_0 
   | - android
   |    | - lib
   |         | - libboost_date_time-gcc-mt-s-1_57.a
   |         | - libboost_random-gcc-mt-s-1_57.a
   |         | - libboost_system-gcc-mt-s-1_57.a
   | - boost
        | - date_time
        |    | - *.hpp
        | - random
        |    | - *.hpp
        | - system
            | - *.hpp

这是我的cmake的相关部分：

option(BUILD_SHARED_LIBS "Build the shared library" OFF)
option(Boost_USE_STATIC_LIBS "Use Boost static version" ON)

set(BOOST_VER "1.57.0" CACHE STRING "boost version" )
set(BOOST_ROOT "/cygdrive/c/boost_1_57_0/")
set(BOOST_INCLUDEDIR "/cygdrive/c/boost_1_57_0/boost/")
set(BOOST_LIBRARYDIR "/cygdrive/c/boost_1_57_0/android/lib/")
# I tried also C: instead of /cygdrive/c, with no success

message(STATUS "BOOST_ROOT = ${BOOST_ROOT}")
message(STATUS "BOOST_INCLUDEDIR = ${BOOST_INCLUDEDIR}")
message(STATUS "BOOST_LIBRARYDIR = ${BOOST_LIBRARYDIR}")

set(Boost_USE_MULTITHREADED ON) 
set(Boost_USE_STATIC_RUNTIME OFF) 
find_package(Boost ${BOOST_VER} REQUIRED COMPONENTS system date_time random)

这是我得到的输出：

$ cmake ./
-- not define build type, set to release
-- BOOST_ROOT = /cygdrive/c/boost_1_57_0/
-- BOOST_INCLUDEDIR = /cygdrive/c/boost_1_57_0/boost/
-- BOOST_LIBRARYDIR = /cygdrive/c/boost_1_57_0/android/lib/
CMake Error at /usr/share/cmake-3.3.2/Modules/FindBoost.cmake:1245 (message):
  Unable to find the requested Boost libraries.

  Boost version: 1.57.0

  Boost include path: /cygdrive/c/boost_1_57_0

  Could not find the following static Boost libraries:

          boost_system
          boost_date_time
          boost_random

  No Boost libraries were found.  You may need to set BOOST_LIBRARYDIR to the
  directory containing Boost libraries or BOOST_ROOT to the location of
  Boost.
Call Stack (most recent call first):
  CMakeLists.txt:32 (find_package)

为什么不起作用？为什么我将BOOST_INCLUDEDIR设置为/cygdrive/c/boost_1_57_0/boost/，但他似乎忽略了它并在whatever I set BOOST_ROOT to中查找包含文件？为什么他也忽略了BOOST_LIBRARYDIR？

Answer 1

好的，我找到了问题的原因。首先，我必须

set(Boost_DEBUG 1)

在我的CMakeLists.txt中，以便find_package(Boost ${BOOST_VER} ... )调用的FindBoost.cmake可以打印出他正在搜索的内容。

所以我发现问题在于：

-- [ /usr/share/cmake-3.3.2/Modules/FindBoost.cmake:827 ] guessed _boost_COMPILER = -gcc46

虽然应该是-gcc，但是：

-- [ /usr/share/cmake-3.3.2/Modules/FindBoost.cmake:1052 ] Searching for SYSTEM_LIBRARY_RELEASE: boost_system-gcc46-mt-1_57

所以我发现变量Boost_LIB_PREFIX没有设置。

第一个问题是由FindBoost.cmake中的_Boost_GUESS_COMPILER_PREFIX函数引起的。出于某种原因，我有这些变量：

CMAKE_CXX_COMPILER_ID : GNU #why?? I'm using Cygwin under Windows...
MINGW :  #unset 
UNIX : 1 
CMAKE_COMPILER_IS_GNUCXX : 1
Boost_MAJOR_VERSION : 1
Boost_MINOR_VERSION : 57

所以在某一点上：

if(${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION} VERSION_LESS 1.34)
    set(_boost_COMPILER "-gcc") # no GCC version encoding prior to 1.34
else()
    ....
    set(_boost_COMPILER "-gcc${_boost_COMPILER_VERSION}")
endif()

第二个问题是由于FindBoost.cmake中的这些行：

set(Boost_LIB_PREFIX "")
if ( (GHSMULTI AND Boost_USE_STATIC_LIBS) OR
    (WIN32 AND Boost_USE_STATIC_LIBS AND NOT CYGWIN) )
  set(Boost_LIB_PREFIX "lib")
endif()

我仍然不明白为什么它不应该添加前缀＆＃34; lib＆＃34;与cygwin。

最终，我并不确切地知道他为什么要搜索错误的库名，也许我搞砸了并使用不同的工具/版本进行编译。

cygwin cmake无法找到boost库

1 个答案: