Question

我通常使用CMake和本地环境在Ubuntu上工作。我的项目编译并运行良好。现在我改为OSX，首先在编译QCustomPlot时收到一些警告：

QCustomPlot/include/qcustomplot.h:6007:15: warning: 
      'findEnd' overrides a member function but is not marked 'override'
      [-Winconsistent-missing-override]
  virtual int findEnd(double sortKey, bool expandedRange=true) const;
              ^
../QCustomPlot/include/qcustomplot.h:3830:15: note: 
      overridden virtual function is here
  virtual int findEnd(double sortKey, bool expandedRange=true) const = 0;

我想我可以压制这个警告。但是，我不喜欢压制警告，如果它们意味着真正的危险。（在Ubuntu下，没有警告）。为什么这是一个警告？我认为覆盖虚函数并不是非常不寻常或危险。

无论如何，有警告，但是没有警告。链接

会出现真正的问题

[  4%] Building CXX object QCustomPlot/CMakeFiles/libQCustomPlot.dir/libQCustomPlot_automoc.cpp.o
[  5%] Linking CXX shared library libQCustomPlot.dylib
Undefined symbols for architecture x86_64:
  "qt_assert_x(char const*, char const*, char const*, int)", referenced from:
      QList<QCPDataRange>::at(int) const in qcustomplot.cpp.o
      QList<QCPDataRange>::operator[](int) in qcustomplot.cpp.o

这是什么问题？（因为使用多平台开发环境，我没想到任何丢失的文件，组件或类似问题。）

编辑：这里是生成它的CMake文件

set(CMAKE_AUTOMOC ON)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
find_package(Qt5 COMPONENTS Core Widgets PrintSupport REQUIRED)

include_directories(
      ${Qt5Widgets_INCLUDE_DIRS}
      ${Qt5Printer_INCLUDE_DIRS}
      include
      )

add_definitions(${Qt5Widgets_DEFINITIONS} ${Qt5Printer_DEFINITIONS})

QT5_WRAP_CPP(qcustomplot_moc include/qcustomplot.h)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${Qt5Widgets_EXECUTABLE_COMPILE_FLAGS}  -std=c++11 -Wall")

ADD_LIBRARY(libQCustomPlot
    qcustomplot.cpp
    ${qcustomplot_moc} # The MOC headers, generated
)

set_target_properties(libQCustomPlot
                      PROPERTIES OUTPUT_NAME QCustomPlot
                      )
target_include_directories(libQCustomPlot PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
)

Answer 1

CMakeLists.txt缺少

行

target_link_libraries(libQCustomPlot Qt5::Widgets)

请参阅Qt documentation on compiling with CMake。此外，除非CMakeLists.txt需要支持3.0以上的CMake版本，否则可以删除许多当前内容。它可以简化为：

set(CMAKE_AUTOMOC ON)
set(CMAKE_INCLUDE_CURRENT_DIR ON)
find_package(Qt5 COMPONENTS Core Widgets PrintSupport REQUIRED)

include_directories(include)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -W -Wall")

ADD_LIBRARY(libQCustomPlot
    qcustomplot.cpp
)

set_target_properties(libQCustomPlot
                      PROPERTIES OUTPUT_NAME QCustomPlot
                      )

target_link_libraries(libQCustomPlot Qt5::Widgets)

target_include_directories(libQCustomPlot PUBLIC
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
)

有关GCC未在未定义引用上失败的更多详细信息，请参见in this question。

警告是关于覆盖另一个函数的函数中缺少override specifier。以下将避免警告：

virtual int findEnd(double sortKey, bool expandedRange=true) const override;

如何为OSX编译QCustomPlot？

1 个答案: