为Android构建Mailcore2

Question

我遵循官方建筑指示来重新编译库。就我而言：

> export ANDROID_SDK=$HOME/Library/Android/sdk
> export ANDROID_NDK=$ANDROID_SDK/ndk-bundle
> ./build.sh

并在编译过程中得到一些错误，如：

[arm64-v8a] Compile++      : MailCore <= MCIMAPAsyncSession.cpp
In file included from /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../include/MailCore/MCObject.h:11:0,
                 from /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../include/MailCore/MCAutoreleasePool.h:5,
                 from /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../include/MailCore/MCBaseTypes.h:5,
                 from /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.h:13,
                 from /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp:9:
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp: In member function 'virtual void mailcore::IMAPAsyncSession::automaticConfigurationDone(mailcore::IMAPSession*)':
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp:874:87: warning: 'virtual mailcore::String* mailcore::IMAPSession::gmailUserDisplayName()' is deprecated (declared at /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/core/imap/MCIMAPSession.h:196) [-Wdeprecated-declarations]
     MC_SAFE_REPLACE_COPY(String, mGmailUserDisplayName, session->gmailUserDisplayName());
                                                                                       ^
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../include/MailCore/MCUtils.h:8:27: note: in definition of macro 'MC_SAFE_COPY'
 #define MC_SAFE_COPY(o) ((o) != NULL ? (o)->copy() : NULL)
                           ^
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp:874:5: note: in expansion of macro 'MC_SAFE_REPLACE_COPY'
     MC_SAFE_REPLACE_COPY(String, mGmailUserDisplayName, session->gmailUserDisplayName());
     ^
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp:874:87: warning: 'virtual mailcore::String* mailcore::IMAPSession::gmailUserDisplayName()' is deprecated (declared at /Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/core/imap/MCIMAPSession.h:196) [-Wdeprecated-declarations]
     MC_SAFE_REPLACE_COPY(String, mGmailUserDisplayName, session->gmailUserDisplayName());
                                                                                       ^
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../include/MailCore/MCUtils.h:8:41: note: in definition of macro 'MC_SAFE_COPY'
 #define MC_SAFE_COPY(o) ((o) != NULL ? (o)->copy() : NULL)
                                         ^
/Users/nikolay/Documents/Mailcore/mailcore2/build-android/jni/../../src/async/imap/MCIMAPAsyncSession.cpp:874:5: note: in expansion of macro 'MC_SAFE_REPLACE_COPY'
     MC_SAFE_REPLACE_COPY(String, mGmailUserDisplayName, session->gmailUserDisplayName());
     ^

... compiling goes ok...
... and again some errors...

诸若此类。最后我得到：

[arm64-v8a] StaticLibrary  : libstdc++.a
[arm64-v8a] SharedLibrary  : libMailCore.so
[arm64-v8a] Install        : libMailCore.so => libs/arm64-v8a/libMailCore.so
warning: [options] bootstrap class path not set in conjunction with -source 1.6
com/libmailcore/MainThreadUtils.java:3: error: package android.os does not exist
import android.os.Handler;
                 ^
com/libmailcore/MainThreadUtils.java:4: error: package android.os does not exist
import android.os.Looper;
                 ^
com/libmailcore/MainThreadUtils.java:5: error: package android.util does not exist
import android.util.Log;
                   ^
com/libmailcore/MainThreadUtils.java:10: error: cannot find symbol
    private Handler handler;
            ^
  symbol:   class Handler
  location: class MainThreadUtils
com/libmailcore/MainThreadUtils.java:21: error: cannot find symbol
        handler = new Handler(Looper.getMainLooper());
                      ^
  symbol:   class Handler
  location: class MainThreadUtils
com/libmailcore/MainThreadUtils.java:21: error: cannot find symbol
        handler = new Handler(Looper.getMainLooper());
                              ^
  symbol:   variable Looper
  location: class MainThreadUtils
6 errors
1 warning

如何重新编译库？最后，我想要修复一个文本重定位错误，但是它甚至没有做一个干净的构建

Answer 1

它正在寻找Android平台16和21，却找不到它们，这就是它显示错误信息的原因：

error: package android.os does not exist

它们通常安装在文件夹$ANDROID_SDK/platforms中。

(将其添加到build-android/build.sh顶部附近，查看它正在做什么：

set -v
set -x

这将显示它正在运行的命令和shell变量的内容。)

如果您打开文件build-android/build.sh，在Mailcore2中，您将看到如下行：

# Start building.
ANDROID_PLATFORM=android-16
archs="armeabi armeabi-v7a x86"

用您安装的任何版本替换android-16，或者更好的是安装android-16，因为它期望这样做。另外，armeabi平台支持已经从最新的Android中删除，这给我带来了一些错误。因此，删除armeabi，只留下armeabi-v7a和x86。

此外，还有以下几个方面：

ANDROID_PLATFORM=android-21
archs="arm64-v8a"

以及：

ANDROID_PLATFORM=android-16
cd "$current_dir/../src/java"
...

因此，安装android-16 和 android-21 来解决此问题是最容易的。

我也收到了错误：

Android NDK: APP_PLATFORM not set. Defaulting to minimum supported version android-16. 

找到这一行：

$ANDROID_NDK/ndk-build TARGET_PLATFORM=$ANDROID_PLATFORM TARGET_ARCH_ABI=$TARGET_ARCH_ABI \

并将APP_PLATFORM添加到其中，就像这样，修正了这个错误：

$ANDROID_NDK/ndk-build TARGET_PLATFORM=$ANDROID_PLATFORM APP_PLATFORM=$ANDROID_PLATFORM TARGET_ARCH_ABI=$TARGET_ARCH_ABI \

我也收到了错误：

*** Android NDK: Invalid NDK_TOOLCHAIN_VERSION value: 4.9. GCC is no longer supported. See https://android.googlesource.com/platform/ndk/+/master/docs/ClangMigration.md.    .  Stop.

显然，GCC不再得到支持。我安装了clang，然后它继续编译该项目，但由于另一个错误而停止。

此外，我还必须删除包含以下内容的行：

NDK_TOOLCHAIN_VERSION=4.9 \

正如所描述的这里。

我收到了错误：

MailCore2/build-android/jni/../../src/java/TypesUtils.cpp:84:32: error: member access into incomplete type 'const std::type_info'
MCLog("info name: %s", info->name());
                           ^

这显然与本期有关

GCC似乎只是含蓄地宣布了std::type_info__。当您第一次使用Clang和libstdc++做一个典型的Hello时，您通常会遇到这个问题。-2月26日至13日20时42分

我还没能解决这个问题，但是我会在有机会的时候更新这篇文章。