gentoo下编译arm64版本Qt5.5 for android
首先下载android sdk ndk 以及Qt源码qt-everywhere-opensource-src-5.5.1.tar.xz解压到/home/gentoo/qt-everywhere-opensource-src-5.5.1,然后在源码外其他位置新建编译目录，首先export ANDROID_API_VERSION=android-21
编译目标为android 5.0
/home/gentoo/qt-everywhere-opensource-src-5.5.1/configure -xplatform android-g++ -nomake tests -nomake examples -android-ndk /opt/android-ndk/ -android-sdk /opt/android-sdk-update-manager -android-ndk-host linux-x86_64 -android-toolchain-version 4.9 -skip qtwebkit -skip qtserialport -skip qttranslations -skip qtwebkit-examples -no-warnings-are-errors -android-ndk-platform android-21 -android-arch arm64-v8a --prefix=/home/gentoo/Qt5.5.1/5.5/android_arm64 -opensource -confirm-licensemake -j8
报错：
In file included from /opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.9/include/random:38:0,
from /opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_algo.h:66,
from /opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.9/include/algorithm:62,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/include/QtCore/../../src/corelib/global/qglobal.h:85,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/include/QtCore/qglobal.h:1,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/include/QtCore/../../src/corelib/thread/qatomic.h:34,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/include/QtCore/qatomic.h:1,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/src/3rdparty/harfbuzz-ng/src/hb-atomic-private.hh:45,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/src/3rdparty/harfbuzz-ng/src/hb-object-private.hh:37,
from /run/media/gentoo/sda5/qt-everywhere-opensource-src-5.5.1/qtbase/src/3rdparty/harfbuzz-ng/src/hb-blob.cc:34:
/opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.9/include/cmath: In function 'constexpr int std::fpclassify(float)':
/opt/android-ndk/sources/cxx-stl/gnu-libstdc++/4.9/include/cmath:562:33: error: 'FP_NAN' was not declared in this scope
{ return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL,
解决:
修改qtbase/src/3rdparty/harfbuzz-ng/Makefile,将里面的-std=c++11删掉
继续make
报错:
qt-everywhere-opensource-src-5.5.1/qtimageformats/src/3rdparty/libwebp/src/dsp/dec.o:dec.c:function VP8DspInit: error: undefined reference to 'VP8DspInitNEON'
解决:
修改qt-everywhere-opensource-src-5.5.1/qtimageformats/src/3rdparty/libwebp/src/dsp/dsp.h
将#define WEBP_USE_NEON改为#define WEBP_USE_NEON1
android arm64似乎不支持neon。
继续make
报错:
qt-everywhere-opensource-src-5.5.1/qttools/src/assistant/3rdparty/clucene/src/CLucene/util/Misc.cpp:24:24: fatal error: sys/timeb.h: No such file or directory
# include
解决：
新版ndk移除了这个头文件，自己touch一个空文件即可
touch /opt/android-ndk/platforms/android-21/arch-arm64/usr/include/sys/timeb.h
继续make
接下来make install
报错：
mkdir: 无法创建目录"/libs": 权限不够
解决：
sudo mkdir /libs
sudo chmod 777 /libs
重新make install
/libs创建了目录arm64-v8a,里面有个文件libqtplugininfo.so,不知道有什么用。
现在可以在qt-creator中添加安装的Qt version了。
但是你会发现用这个版本的Qt编译出来的程序无法在android5.x下运行，这不是Qt的错，是android的bug.
在androidl下，如果一个app是arm64-v8a的，假设包名为org.qt.example,那么/data/data/org.qt.example/lib是一个无效的软链接，指向了错误的位置。
所以我们要在Qt中修复这个链接。
在安装目录android_arm64/src/android/java/src/org/qtproject/qt5/android/bindings/QtActivity.java文件中增加几行：
+++ QtActivity.java 2015-12-26 21:29:24.000000000 +0800
@@ -37,6 +37,7 @@
package org.qtproject.qt5.android.bindings;
import java.io.File;
+import android.system.Os;
import java.io.IOException;
import java.io.OutputStream;
import java.io.InputStream;
@@ -843,6 +844,11 @@
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
+ try{
+ Os.remove(getApplicationInfo().dataDir+"/lib");
+ Os.symlink(getApplicationInfo().nativeLibraryDir,getApplicationInfo().dataDir+"/lib");
+ }catch(Exception e){}
+
try {
m_activityInfo = getPackageManager().getActivityInfo(getComponentName(), PackageManager.GET_META_DATA);重新构建Qt工程，部署到手机上即可成功运行。