iOS/AOT: XmlSerializer.Deserialize throws Attempting to JIT compile method 'void Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializerContract:.ctor ()' while running in aot-only mode.

[rolfbjarne]

Description

Calling XmlSerializer.Deserialize ends up throwing a System.ExecutionEngineException: "Attempting to JIT compile method 'void Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializerContract:.ctor ()' while running in aot-only mode."

EXCEPTION: System.InvalidOperationException: XmlSerializeErrorDetails, 0, 0
 ---> System.ExecutionEngineException: Attempting to JIT compile method 'void Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializerContract:.ctor ()' while running in aot-only mode. See https://docs.microsoft.com/xamarin/ios/internals/limitations for more information.
   at System.Reflection.RuntimeConstructorInfo.InternalInvoke(Object , Object[] , Boolean ) in System.Private.CoreLib.dll:token 0x600269a+0x5
   Exception_EndOfInnerExceptionStack
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader , String , XmlDeserializationEvents ) in System.Private.Xml.dll:token 0x6001b05+0x10d
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader , String ) in System.Private.Xml.dll:token 0x6001b04+0x0
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader ) in System.Private.Xml.dll:token 0x6001b02+0x0
   at MySimpleApp.Program.XmlSerializationTest.Response.Deserialize(String xml) in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 67
   at MySimpleApp.Program.XmlSerializationTest.Bug1820_GenericList() in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 184
   at MySimpleApp.Program.Main(String[] args) in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 22

Test code: https://github.com/rolfbjarne/xamarin-macios/blob/c8014a6b6fd759159b409df19062f11b57ae8e2c/tests/dotnet/MySimpleApp/AppDelegate.cs#L21-L187

To reproduce:

1. Download & install Xcode 13 beta 3.

2. Clone my fork of xamarin-macios, and checkout the Bug1820_GenericList-testcase branch, and build it:

    git clone https://github.com/rolfbjarne/xamarin-macios
    git checkout Bug1820_GenericList-testcase
    cd xamarin-macios
    ./configure --enable-dotnet --enable-xamarin
    make reset
    make all -j8
    make install -j8
   

3. Connect an iOS device

4. Build & run the test project:

    make -C tests/dotnet/MySimpleApp/iOS run-dev
   

Configuration

6.0.100-rc.1.21377.4

Regression?

With regards to legacy Xamarin, yes.

[rolfbjarne]

CC @steveisok

[steveisok]

@MaximLipnin We probably want to set ReflectionOnly as a default for iOS, tvOS, and MacCatalyst.

runtime/src/libraries/System.Private.Xml/src/System/Xml/Serialization/XmlSerializer.cs

Line 112 in 8b87ada

internal static SerializationMode Mode { get; set; } = SerializationMode.ReflectionAsBackup;

Tagging subscribers to 'arch-ios': @steveisok, @akoeplinger
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

Calling XmlSerializer.Deserialize ends up throwing a System.ExecutionEngineException: "Attempting to JIT compile method 'void Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializerContract:.ctor ()' while running in aot-only mode."

EXCEPTION: System.InvalidOperationException: XmlSerializeErrorDetails, 0, 0
 ---> System.ExecutionEngineException: Attempting to JIT compile method 'void Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializerContract:.ctor ()' while running in aot-only mode. See https://docs.microsoft.com/xamarin/ios/internals/limitations for more information.
   at System.Reflection.RuntimeConstructorInfo.InternalInvoke(Object , Object[] , Boolean ) in System.Private.CoreLib.dll:token 0x600269a+0x5
   Exception_EndOfInnerExceptionStack
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader , String , XmlDeserializationEvents ) in System.Private.Xml.dll:token 0x6001b05+0x10d
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader , String ) in System.Private.Xml.dll:token 0x6001b04+0x0
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader ) in System.Private.Xml.dll:token 0x6001b02+0x0
   at MySimpleApp.Program.XmlSerializationTest.Response.Deserialize(String xml) in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 67
   at MySimpleApp.Program.XmlSerializationTest.Bug1820_GenericList() in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 184
   at MySimpleApp.Program.Main(String[] args) in /Users/rolf/work/maccore/main/xamarin-macios/tests/dotnet/MySimpleApp/AppDelegate.cs:line 22

Test code: https://github.com/rolfbjarne/xamarin-macios/blob/c8014a6b6fd759159b409df19062f11b57ae8e2c/tests/dotnet/MySimpleApp/AppDelegate.cs#L21-L187

To reproduce:

1. Download & install Xcode 13 beta 3.

2. Clone my fork of xamarin-macios, and checkout the Bug1820_GenericList-testcase branch, and build it:

    git clone https://github.com/rolfbjarne/xamarin-macios
    git checkout Bug1820_GenericList-testcase
    cd xamarin-macios
    ./configure --enable-dotnet --enable-xamarin
    make reset
    make all -j8
    make install -j8
   

3. Connect an iOS device

4. Build & run the test project:

    make -C tests/dotnet/MySimpleApp/iOS run-dev
   

Configuration

6.0.100-rc.1.21377.4

Regression?

With regards to legacy Xamarin, yes.

Author:	rolfbjarne
Assignees:	MaximLipnin
Labels:	area-Serialization, os-ios, os-maccatalyst, os-tvos
Milestone:	6.0.0

[rolfbjarne]

This looks similar to #47114 (comment) (make the serialization mode dependent on RuntimeFeature.IsDynamicCodeSupported).