交叉编译中的CMake CMAKE_AUTOMOC [英] CMake CMAKE_AUTOMOC in cross compilation

问题描述

我正在关注问题。我正在尝试使用CMake中的本机机制进行交叉编译。我准备了以下toolchain.cmake文件：

I've following issue. I'm tring to use native mechanism build in CMake for cross compilation. I prepared following toolchain.cmake file:

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)

set(CMAKE_SYSROOT /tmp/filesystem)

set(tools /opt/gcc-linaro-arm-linux-gnueabihf-4.8-2014.04_linux/bin/arm-linux-gnueabihf)
set(CMAKE_C_COMPILER ${tools}-gcc)
set(CMAKE_CXX_COMPILER ${tools}-g++)

set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

并在目标 CMakeList.txt 被使用：

set(CMAKE_AUTOMOC ON)

我希望当我使用 CMAKE_FIND_ROOT_PATH_MODE_PROGRAM 设置为 Never 根据文档，CMake将使用 HOST 中的moc：

I expect that when I use CMAKE_FIND_ROOT_PATH_MODE_PROGRAM set to NEVER the CMake, according to documentation, will use moc from HOST:

如果设置为NEVER，则根目录为CMAKE_FIND_ROOT_PA TH将被
忽略，仅使用主机系统根目录。

If set to NEVER, then the roots in CMAKE_FIND_ROOT_PATH will be ignored and only the host system root will be used.

但是它仍然尝试使用 TARGET 手臂映像rootfs。

However it still try to use moc from TARGET arm image rootfs.

我尝试重新引用moc可执行文件，如本帖子的第一个答案：如何使用CMake包括某些Qt安装？但没有

I try to refind the moc executable like in first answer from this post: How to include a certain Qt installation using CMake? but with no luck.

我还尝试将 QT_MOC_EXECUTABLE 变量设置为从 HOST rootfs而不是 TARGET 之一，但也没有运气。我事件认为将 CMAKE_AUTOMOC 设置为 ON 时，CMake不使用此变量，因为在强制更改后此缓存变量cmake仍然使用 TARGET rootfs中的moc。

I also try to set the QT_MOC_EXECUTABLE variable to proper path from HOST rootfs instead of TARGET one but also with no luck there. I event think that this variable isn't use by CMake when CMAKE_AUTOMOC is set to ON since after forcing change this cached variable cmake still use moc from TARGET rootfs.

有什么想法可以解决此问题吗？

Any ideas how to resolve this issue?

＃编辑1

我发现automoc在生成文件夹中生成了此类文件：

I found that the automoc generates such file in build folder:

CMakeFiles / * target_name * _automoc.dir / AutogenInfo.cmake

在我的情况下，此类变量设置为错误的路径：

And in my case such variable is set to wrong path:

set（AM_QT_MOC_EXECUTABLE / tmp / filesystem / usr / lib / arm- linux-gnueabihf / qt5 / bin / moc）

应为：

set（AM_QT_MOC_EXECUTABLE / usr / bin / moc）

我设置 AM_QT_MOC_EXECUTABLE 来更正主 CMakeList.txt 中的值，但仍然在从 TARGET rootfs。

I set AM_QT_MOC_EXECUTABLE to correct value in main CMakeList.txt but still after mentioned file is generated with wrong path from TARGET rootfs.

推荐答案

由于这篇文章，我终于找到了解决方案：如何将CMake的AUTOMOC功能与自定义Qt软件包一起使用？。我假设 AUTOMOC 不直接使用 QT_MOC_EXECUTABLE 。

I finally found the solution thanks to this post: How can I use CMake's AUTOMOC feature with a custom Qt package?. As I assumed the QT_MOC_EXECUTABLE isn't use directly by AUTOMOC.

在第一个qt find_package 之前必须添加以下行：

Before first qt find_package following lines must be added:

set(QT_MOC_EXECUTABLE /usr/bin/moc)
add_executable(Qt5::moc IMPORTED)
set_property(TARGET Qt5::moc PROPERTY IMPORTED_LOCATION ${QT_MOC_EXECUTABLE})

这里的问题是不仅变量 QT_MOC_EXECUTABLE 必须设置为适当的值但最后automoc仅使用 Qt5：moc 目标，必须在将任何qt软件包包含在 CMakeList.txt 文件。

The issue here was that not only the variable QT_MOC_EXECUTABLE has to be set to proper value but finally the automoc uses just Qt5:moc target which must be declared before any qt package will be included in CMakeList.txt file.

其他qt工具也存在此问题，因此更通用的选择是：

This same issue is with other qt tools so more generic option will be:

file(GLOB Qt_bin /usr/bin)
find_program(QT_MOC_EXECUTABLE qt_moc moc PATHS ${Qt_bin})
add_executable(Qt5::moc IMPORTED)
set_property(TARGET Qt5::moc PROPERTY IMPORTED_LOCATION ${QT_MOC_EXECUTABLE})

这篇关于交叉编译中的CMake CMAKE_AUTOMOC的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！