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[Mono.Android] handle exceptions in RegisterNativeMembers #6672

Merged
merged 1 commit into from
Jan 27, 2022
Merged

[Mono.Android] handle exceptions in RegisterNativeMembers #6672

merged 1 commit into from
Jan 27, 2022

Commits on Jan 26, 2022

  1. [Mono.Android] handle exceptions in RegisterNativeMembers 

    Context: dotnet/maui#4262

`dotnet new maui-blazor` crashes at runtime, if you do:

    dotnet build -t:Run -c Release

You can turn *off* the linker to solve this issue:

    dotnet build -t:Run -c Release -p:AndroidLinkMode=None

(or `PublishTrimmed=false`)

The app crashes in way that you get a native crash:

    backtrace:
    #00 pc 000000000065d8fc  /apex/com.android.art/lib64/libart.so (void art::StackVisitor::WalkStack<(art::StackVisitor::CountTransitions)0>(bool)+156) (BuildId: 7fbaf2a1a3317bd634b00eb90e32291e)
    #1 pc 000000000069b25d  /apex/com.android.art/lib64/libart.so (art::Thread::GetCurrentMethod(unsigned int*, bool, bool) const+157) (BuildId: 7fbaf2a1a3317bd634b00eb90e32291e)
    #2 pc 0000000000430fed  /apex/com.android.art/lib64/libart.so (art::JNI<false>::FindClass(_JNIEnv*, char const*)+765) (BuildId: 7fbaf2a1a3317bd634b00eb90e32291e)
    #3 pc 0000000000047e5a  /data/app/~~0Qm6D1S0sO3f1lwfakN0PA==/com.companyname.mauiapp2-08UokVCH5k_PlbZEH_hhkA==/split_config.x86_64.apk!libmono-android.release.so (offset 0x11e000) (java_interop_jnienv_find_class+26) (BuildId: 3d04f8b946590175e97b89aee2e3b19ceed4b524)
    #4 pc 00000000000128ac  <anonymous:41640000>

After much investigation... We found that
`Java.IO.InputStreamHandler.GetReadHandler()` was linked away.

This is because:

1. `Mono.Android.dll` has it's Java stubs precompiled into
   `mono.android.jar` and `mono.android.dex`.

2. Since `Mono.Android.dll` doesn't go through `GenerateJavaStubs`,
   the linker has no way to know if the missing method is used -- it
   is only called from Java in the crashing app.

To make the crash better, we need to `try-catch` *all* exceptions in
`RegisterNativeMembers()` and pass them to
`AndroidRuntime.RaisePendingException()`. This is because
`RegisterNativeMembers()` is called directly from Java.

Now the crash shows:

    01-26 12:20:20.290 29264 29264 I MonoDroid: Android.Runtime.JavaProxyThrowable: Exception_WasThrown, Android.Runtime.JavaProxyThrowable
    01-26 12:20:20.290 29264 29264 I MonoDroid:
    01-26 12:20:20.290 29264 29264 I MonoDroid:   --- End of managed Android.Runtime.JavaProxyThrowable stack trace ---
    01-26 12:20:20.290 29264 29264 I MonoDroid: android.runtime.JavaProxyThrowable: System.ArgumentException: Arg_DlgtTargMeth
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at System.Delegate.CreateDelegate(Type , Type , String , Boolean , Boolean )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at System.Delegate.CreateDelegate(Type , Type , String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.AndroidTypeManager.RegisterNativeMembers(JniType , Type , String )
    01-26 12:20:20.290 29264 29264 I MonoDroid: --- End of stack trace from previous location ---
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Java.Interop.JniEnvironment.StaticMethods.CallStaticObjectMethod(JniObjectReference , JniMethodInfo , JniArgumentValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.CallStaticObjectMethod(IntPtr , IntPtr , JValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.CallStaticObjectMethod(IntPtr , IntPtr , JValue[] )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.FindClass(String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.AllocObject(String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue[] )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.InputStreamAdapter..ctor(Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.InputStreamAdapter.ToLocalJniHandle(Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Webkit.WebResourceResponse..ctor(String , String , Int32 , String , IDictionary`2 , Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Microsoft.AspNetCore.Components.WebView.Maui.WebKitWebViewClient.ShouldInterceptRequest(WebView view, IWebResourceRequest request)
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Webkit.WebViewClient.n_ShouldInterceptRequest_Landroid_webkit_WebView_Landroid_webkit_WebResourceRequest_(IntPtr , IntPtr , IntPtr , IntPtr )
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at crc64d693e2d9159537db.WebKitWebViewClient.n_shouldInterceptRequest(Native Method)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at crc64d693e2d9159537db.WebKitWebViewClient.shouldInterceptRequest(WebKitWebViewClient.java:39)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at Rr.a(chromium-TrichromeWebViewGoogle.apk-stable-410410686:16)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at org.chromium.android_webview.AwContentsBackgroundThreadClient.shouldInterceptRequestFromNative(chromium-TrichromeWebViewGoogle.apk-stable-410410686:2)
    01-26 12:20:20.290 29264 29264 I MonoDroid:
    01-26 12:20:20.290 29264 29264 I MonoDroid:   --- End of managed Android.Runtime.JavaProxyThrowable stack trace ---
    01-26 12:20:20.290 29264 29264 I MonoDroid: android.runtime.JavaProxyThrowable: System.ArgumentException: Arg_DlgtTargMeth
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at System.Delegate.CreateDelegate(Type , Type , String , Boolean , Boolean )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at System.Delegate.CreateDelegate(Type , Type , String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.AndroidTypeManager.RegisterNativeMembers(JniType , Type , String )
    01-26 12:20:20.290 29264 29264 I MonoDroid: --- End of stack trace from previous location ---
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Java.Interop.JniEnvironment.StaticMethods.CallStaticObjectMethod(JniObjectReference , JniMethodInfo , JniArgumentValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.CallStaticObjectMethod(IntPtr , IntPtr , JValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.CallStaticObjectMethod(IntPtr , IntPtr , JValue[] )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.FindClass(String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.AllocObject(String )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue* )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue[] )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.InputStreamAdapter..ctor(Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Runtime.InputStreamAdapter.ToLocalJniHandle(Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Webkit.WebResourceResponse..ctor(String , String , Int32 , String , IDictionary`2 , Stream )
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Microsoft.AspNetCore.Components.WebView.Maui.WebKitWebViewClient.ShouldInterceptRequest(WebView view, IWebResourceRequest request)
    01-26 12:20:20.290 29264 29264 I MonoDroid:    at Android.Webkit.WebViewClient.n_ShouldInterceptRequest_Landroid_webkit_WebView_Landroid_webkit_WebResourceRequest_(IntPtr , IntPtr , IntPtr , IntPtr )
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at crc64d693e2d9159537db.WebKitWebViewClient.n_shouldInterceptRequest(Native Method)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at crc64d693e2d9159537db.WebKitWebViewClient.shouldInterceptRequest(WebKitWebViewClient.java:39)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at Rr.a(chromium-TrichromeWebViewGoogle.apk-stable-410410686:16)
    01-26 12:20:20.290 29264 29264 I MonoDroid: 	at org.chromium.android_webview.AwContentsBackgroundThreadClient.shouldInterceptRequestFromNative(chromium-TrichromeWebViewGoogle.apk-stable-410410686:2)

This is much easier to reason about, and will save us time in the future.

A fix to the actual linker problem will be coming in another PR.
    @jonathanpeppers
    jonathanpeppers committed Jan 26, 2022
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