如何使用 CMake 在我的项目中链接已编译的 cmph 库

Question

为了在使用 CMake 组织的项目中使用完美的最小哈希库 cmph，我在 ubuntu 机器上安装了 cmph 库，并使用名为 main.c 的单个 c 文件对其进行了测试。

如果我尝试使用 gcc 5.3.0 使用以下命令编译此文件：

gcc main.c

我会得到以下输出

/tmp/ccSOH5ob.o: In function `main':
testperfect.c:(.text+0x63): undefined reference to   `cmph_io_vector_adapter'
testperfect.c:(.text+0x73): undefined reference to `cmph_config_new'
testperfect.c:(.text+0x88): undefined reference to `cmph_config_set_algo'
testperfect.c:(.text+0x9b): undefined reference to `cmph_config_set_mphf_fd'
testperfect.c:(.text+0xa7): undefined reference to `cmph_new'
testperfect.c:(.text+0xb7): undefined reference to `cmph_config_destroy'
testperfect.c:(.text+0xca): undefined reference to `cmph_dump'
testperfect.c:(.text+0xd6): undefined reference to `cmph_destroy'
testperfect.c:(.text+0xe2): undefined reference to `cmph_load'
testperfect.c:(.text+0x118): undefined reference to `cmph_search'
testperfect.c:(.text+0x153): undefined reference to `cmph_destroy'
testperfect.c:(.text+0x15f): undefined reference to  `cmph_io_vector_adapter_destroy'

但是如果我运行这个命令：

gcc main.c $(pkg-config --libs cmph) -o main

它将被编译并正常运行。

现在我需要在我的项目中添加一段类似的代码，CMakeList.txt 是这样写的：

set(PROJECT_EXECUTABLE ${PROJECT_NAME}) 

# Compiling flags. 
if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR 
   CMAKE_CXX_COMPILER_ID MATCHES "Clang") 
  set(CMAKE_CXX_FLAGS_RELEASE        "-O2") 
  set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g") 
  set(CMAKE_CXX_FLAGS_DEBUG          "-g") 
  set(CMAKE_CXX_FLAGS_MINSIZEREL     "-Os") 
  endif() 
# Inject project config. 
configure_file( 
  ${PROJECT_INCLUDE_DIR}/phsim/config.hpp.in 
  ${PROJECT_INCLUDE_DIR}/phsim/config.hpp 
  ) 

include(FindPkgConfig) 
find_package(PkgConfig REQUIRED) 
pkg_search_module(CMPH REQUIRED cmph) 
target_link_libraries(Phsim ${CMPH_LIBRARIES}) 
target_include_directories(Phsim PUBLIC ${CMPH_INCLUDE_DIRS}) 
target_compile_options(Phsim PUBLIC ${CMPH_CFLAGS_OTHER}) 

# Compile executable. 
file(GLOB SOURCES ${PROJECT_SRC_DIR}/*.cpp) 
add_executable(${PROJECT_EXECUTABLE} ${SOURCES}) 

set_target_properties(${PROJECT_EXECUTABLE} PROPERTIES 
  VERSION ${PHSIM_VERSION_LITER} 
  ) 

然后我尝试运行 cmake 。和make，但只得到错误信息：

CMake Error at src/CMakeLists.txt:20 (target_link_libraries):
  Cannot specify link libraries for target "Phsim" which is not built by this
  project.

但是除非我编译项目，否则我不会得到目标可执行文件。如果我尝试在没有与库链接相关的命令的情况下编译我的项目，编译器将给出问题开头提供的类似链接错误。

我检查了以下问题：

Undefined reference to cmph functions even after installing cpmh library

我尝试了这些网站提供的说明：

https://cmake.org/Wiki/CMake:How_To_Find_Libraries

https://cmake.org/cmake/help/v3.6/module/FindPkgConfig.html

非常感谢。

Answer 1

终于解决了。

cmake_minimum_required(VERSION 3.0.2)
project(TestGamma)

set(GAMMATEST_VERSION_MAJOR 1)
set(GAMMATEST_VERSION_MINOR 0)
set(CMPH_INCLUDE_DIR /usr/local/lib)

include(FindPkgConfig)
configure_file(
    "${PROJECT_SOURCE_DIR}/TestGammaConfig.h.in"
    "${PROJECT_BINARY_DIR}/TestGammaConfig.h"
)

include_directories(${PROJECT_BINARY_DIR})

set(CMAKE_CXX_FLAGS " ${CMAKE_CXX_FLAGS} -std=c++11")

set(SOURCE_FILES main.cpp)

add_executable(testgamma ${SOURCE_FILES})
pkg_check_modules(CMPH REQUIRED cmph)
include_directories(${CMPH_INDLUDE_DIR})
link_directories(${CMPH_INCLUDE_DIR})
target_link_libraries(testgamma cmph ${CMPH_INCLUDE_DIR})

确保首先包含pkgconfig，并在调用“add_executable”后添加链接操作

@usr1234567 感谢您的关注。