MathGL和Cmake

Question

我試圖運行mathgl與cmake，我遇到了一些問題。該文件test001.cpp的代碼如下：

#include <stdio.h> 
#include <mgl2/qt.h> 
int sample(mglGraph *gr) 
{ 
    gr->Rotate(60,40); 
    gr->Box(); 
    return 0; 
} 
int main(int argc,char **argv) 
{ 
    mglQT gr(sample,"MathGL examples"); 
    return gr.Run(); 
} 

我這個CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3) 
project (test001) 
SET(CMAKE_MODULE_PATH ${test001_SOURCE_DIR}) 

# FIND_PACKAGE(Qt REQUIRED) 
find_package(MathGL) 
include_directories(
    ${MathGL_INCLUDE_DIRS} 
) 
add_executable(test001 test001.cpp) 
target_link_libraries(test001 ${MathGL_LIBRARIES}) 

這就需要下面cmake module編譯：

FIND_PATH(MATHGL_INCLUDE_DIR NAMES mgl2/mgl.h 
    PATHS 
    /opt/local/include 
    /usr/include 
    /usr/local/include 
) 

FIND_LIBRARY(MATHGL_LIB NAMES mgl 
    PATHS 
    /opt/local/lib 
    /usr/local/lib 
    /usr/lib 
) 

IF (MATHGL_INCLUDE_DIR AND MATHGL_LIB) 
    SET(MATHGL_FOUND TRUE) 
    MESSAGE(STATUS "MATHGL found") 
    MESSAGE(STATUS "MATHGL Include dirs:" ${MATHGL_INCLUDE_DIR}) 
    MESSAGE(STATUS "MATHGL Library:" ${MATHGL_LIB}) 
ELSE (MATHGL_INCLUDE_DIR AND MATHGL_LIB) 
    MESSAGE(STATUS "MATHGL was not found") 
ENDIF(MATHGL_INCLUDE_DIR AND MATHGL_LIB) 

所有文件都在同夾。

我跑那麼cmake ..一個文件夾，名爲內搭，我也得到明顯一個很好的答案：

-- The C compiler identification is GNU 4.9.2 
-- The CXX compiler identification is GNU 4.9.2 
-- Check for working C compiler: /usr/bin/cc 
-- Check for working C compiler: /usr/bin/cc -- works 
-- Detecting C compiler ABI info 
-- Detecting C compiler ABI info - done 
-- Check for working CXX compiler: /usr/bin/c++ 
-- Check for working CXX compiler: /usr/bin/c++ -- works 
-- Detecting CXX compiler ABI info 
-- Detecting CXX compiler ABI info - done 
-- MATHGL found 
-- MATHGL Include dirs:/usr/include 
-- MATHGL Library:/usr/lib/libmgl.so 
-- Configuring done 
-- Generating done 
-- Build files have been written to: /home/fogg/dev/c/mathgl/build 

但後來我得到一個編譯錯誤，如果我沒有鏈接程序，但我做的它在CMakeLists.txt文件中。

Scanning dependencies of target test001 
[100%] Building CXX object CMakeFiles/test001.dir/test001.cpp.o 
Linking CXX executable test001 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::mglGraph(int, int, int)': 
test001.cpp:(.text._ZN8mglGraphC2Eiii[_ZN8mglGraphC5Eiii]+0x3b): undefined reference to `mgl_create_graph_gl' 
test001.cpp:(.text._ZN8mglGraphC2Eiii[_ZN8mglGraphC5Eiii]+0x57): undefined reference to `mgl_create_graph' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::~mglGraph()': 
test001.cpp:(.text._ZN8mglGraphD2Ev[_ZN8mglGraphD5Ev]+0x28): undefined reference to `mgl_use_graph' 
test001.cpp:(.text._ZN8mglGraphD2Ev[_ZN8mglGraphD5Ev]+0x42): undefined reference to `mgl_delete_graph' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::SetFontSize(double)': 
test001.cpp:(.text._ZN8mglGraph11SetFontSizeEd[_ZN8mglGraph11SetFontSizeEd]+0x2a): undefined reference to `mgl_set_font_size' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::Rotate(double, double, double)': 
test001.cpp:(.text._ZN8mglGraph6RotateEddd[_ZN8mglGraph6RotateEddd]+0x4e): undefined reference to `mgl_rotate' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglGraph::Box(char const*, bool)': 
test001.cpp:(.text._ZN8mglGraph3BoxEPKcb[_ZN8mglGraph3BoxEPKcb]+0x2c): undefined reference to `mgl_box_str' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglQT::mglQT(int (*)(mglGraph*), char const*)': 
test001.cpp:(.text._ZN5mglQTC2EPFiP8mglGraphEPKc[_ZN5mglQTC5EPFiP8mglGraphEPKc]+0x34): undefined reference to `mgl_draw_graph' 
test001.cpp:(.text._ZN5mglQTC2EPFiP8mglGraphEPKc[_ZN5mglQTC5EPFiP8mglGraphEPKc]+0x50): undefined reference to `mgl_create_graph_qt' 
CMakeFiles/test001.dir/test001.cpp.o: In function `mglQT::Run()': 
test001.cpp:(.text._ZN5mglQT3RunEv[_ZN5mglQT3RunEv]+0xd): undefined reference to `mgl_qt_run' 
collect2: error: ld returned 1 exit status 
make[2]: *** [test001] Error 1 
make[1]: *** [CMakeFiles/test001.dir/all] Error 2 
make: *** [all] Error 2 

附註：當使用g++ test001.cpp -lmgl-qt -lmgl -o test001時，該程序的編譯效果非常好。有任何想法嗎？

Answer 1

我正在使用FindMathGL.cmake，我從this site下載它，顯然它包含一些錯誤。我糾正了這個文件，然後發佈它，這對未來的某個人可能會有用。

FIND_PATH(MathGL_INCLUDE_DIRS NAMES mgl2/mgl.h 
    PATHS 
    /opt/local/include 
    /usr/include 
    /usr/local/include 
) 

FIND_LIBRARY(MathGL_LIB NAMES mgl 
    PATHS 
    /opt/local/lib 
    /usr/local/lib 
    /usr/lib 
) 
FIND_LIBRARY(MathGL_QT_LIB NAMES mgl-qt 
    PATHS 
    /opt/local/lib 
    /usr/local/lib 
    /usr/lib 
) 


SET(MathGL_LIBRARIES ${MathGL_LIB} ${MathGL_QT_LIB}) 

IF (MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES) 
    SET(MathGL_FOUND TRUE) 
    MESSAGE(STATUS "MathGL found") 
    MESSAGE(STATUS "MathGL Include dirs:" ${MathGL_INCLUDE_DIRS}) 
    MESSAGE(STATUS "MathGL Library:" ${MathGL_LIB}) 
ELSE (MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES) 
    MESSAGE(STATUS "MathGL was not found") 
ENDIF(MathGL_INCLUDE_DIRS AND MathGL_LIBRARIES)