# Tuesday, 23 October 2012
IKVM.NET 7.2 Release Candidate 3

The stream of release candidates seems to never end, but I really wanted to include the fix for bug #3575555. I also included some other low-risk fixes.

Changes (relative to rc 2):

  • Updated version to 7.2.4630.3
  • Bug fix. Off-by-one error in JNI local ref index reusing. Fix for bug #3575555.
  • Bug fix. Don't try to inject DynamicMethod in array types (applies to array.clone() method for MethodHandles).
  • IKVM.Reflection: Bug fix. ModuleReader.ResolveMember() should support types. Thanks to Jb Evain for finding this.
  • IKVM.Reflection: Bug fix. While reading the Mono.Cecil source I realized that array bounds are signed.
  • IKVM.Reflection: Bug fix. LocalBuilder should extend LocalVariableInfo.
  • IKVM.Reflection: Implemented LocalVariableInfo.ToString().

Binaries available here: ikvmbin-7.2.4630.3.zip

Sources: ikvmsrc-7.2.4630.3.zip, openjdk-7u6-b24-stripped.zip

Tuesday, 23 October 2012 10:24:01 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Monday, 08 October 2012
IKVM.NET 7.2 Release Candidate 2

More bug fixes.

Changes (relative to rc 1):

  • Updated version to 7.2.4630.2
  • Bug fix. Class.forName("") should not throw System.ArgumentException.
  • Bug fix. Transient field modifier should be retained on literal fields.
  • Bug fix. Field.getModifiers() should only return the relevant modifiers.
  • IKVM.Reflection: Bug fix. Ignore unknown metadata streams.
  • IKVM.Reflection: Bug fix. Set AddressOfRawData in IMAGE_DEBUG_DIRECTORY.

Binaries available here: ikvmbin-7.2.4630.2.zip

Sources: ikvmsrc-7.2.4630.2.zip, openjdk-7u6-b24-stripped.zip

Monday, 08 October 2012 09:48:54 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Wednesday, 03 October 2012
IKVM.NET 0.46 Update 2 Release Candidate 1

I forgot to include the fix for transient constant static final fields in the previous release candidate and a new bug was reported in how IKVM.Reflection writes the debug PE header that causes problems with Visual Studio 2012's code coverage tools.

Changes (relative to 0.46 Update 2 rc 0):

  • Updated version to 0.46.0.4.
  • Fixed ikvmc to retain transient modifier on constant static final fields.
  • Fixed Field.getModifiers() to only return the relevant modifiers.
  • Fixed IKVM.Reflection to set AddressOfRawData in IMAGE_DEBUG_DIRECTORY.

Binaries available here: ikvmbin-0.46.0.4.zip

Sources: ikvmsrc-0.46.0.4.zip, openjdk6-b22-stripped.zip

Wednesday, 03 October 2012 08:26:59 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Thursday, 27 September 2012
Bye Bye ConstructorBuilder

System.Reflection.Emit is a great .NET feature, especially if you consider that it shipped as part of .NET 1.0, but the design of System.Reflection.Emit leaves something to be desired.

One of the crazy features is ConstructorBuilder. On the System.Reflection side, ConstructorInfo isn't all that helpful, but it is not as actively harmful as ConstructorBuilder. The reason for this is that ConstructorInfo and MethodInfo both extend MethodBase, so most common APIs are available through MethodBase.

ConstructorBuilder and MethodBuilder share no common Builder base class (because they extend ConstructorInfo and MethodInfo), this causes a lot of code duplication and type testing/downcasting.

A long time ago I found out that you can mostly avoid ConstructorBuilder, since it is possible to use TypeBuilder.DefineMethod() to define constructors. Recently I finally got around to taking advantage of this and completely removing ConstructorBuiler from the IKVM.NET runtime and compiler.

The thing that pushed me over the edge was this experiment. In .NET 2.0 there is no ConstructorBuilder equivalent to MethodBuilder.CreateMethodBody(). So if I'm ever going to experiment with method level JIT it is nice to be able to use this more efficient method of installing the stub.

There is one problem with using MethodBuilder for constructors. If you define a custom attribute and want to apply that custom attribute while it is still unbaked, you need a ConstructorBuilder for the custom attribute constructor, because CustomAttributeBuilder requires it. Luckily, in dynamic mode IKVM doesn't need to do this and in static mode I use IKVM.Reflection so I added MethodInfo.__AsConstructorInfo() to wrap the MethodInfo in a ConstructorInfo.

I considered adding MethodInfo support to CustomAttributeBuilder, but that turned out to be much more complicated, so I went with the easy approach of reusing the existing wrapping strategy.

The result of this refactoring is the removal of a bunch of duplicate code and a lot of downcasting. It also saves a small bit of memory, because the ConstructorBuilder wrappers are not needed anymore.

Thursday, 27 September 2012 14:29:05 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Wednesday, 26 September 2012
IKVM.NET 0.46 Update 2 Release Candidate 0

The 0.46 version is the last version based on Java 6 and as mentioned previously would be supported longer than a typical release. Based on user feedback I decided to post an update that fixes a number of bugs that have been found since the previous release.

Changes (relative to 0.46 Update 1):

  • Updated version to 0.46.0.3.
  • Bug fix. java.lang.Package was not populated from manifest for ikvmc compiled assemblies.
  • Bug fix. When writing a direct ByteBuffer to a non-blocking socket and the write fails because there is no kernel buffer available, we should not advance the ByteBuffer position.
  • Bug fix. When adding certificates to virtual cacerts file make sure that the aliases are unique.
  • Bug fix. If a finally/fault handler contains reachable code before the handler's start index, the handler should branch to the handler start index.
  • Bug fix. After emitting a finally/fault handler block, we should emit the block leave stubs (even though you can't leave the block, they also emit the backward branch stubs).
  • Bug fix. If a Java class extends a remapped .NET type (cli.System.Object or cli.System.Exception), we should correctly report the base class.
  • Bug fix. If we encounter a jsr or ret instruction, we should throw a VerifyError (instead of NotImplementedException).
  • Bug fix. If an exception block ends with an astore, we need to propagate the local variable type after the astore to the exception handler.
  • Disable AppDomain.ProcessExit hook to run shutdown hooks when running on Mono to workaround https://bugzilla.xamarin.com/show_bug.cgi?id=5650
  • Bug fix. Custom attribute properties that don't have a public getter and setter should not be exposed as annotation properties.
  • Bug fix. Non-public property getter/setter methods should be ignored when we create properties to hide properties inherited from shadow types. This fixes a build break with .NET 4.5 beta which introduces a protected setter for Exception.HResult.
  • Bug fix. The $Method inner class for delegates should also be loadable for generic delegates. Thanks to Michael Bayne for reporting this.
  • Bug fix. When constructing a generic class loader we can't use GetWrapperFromType() on the type arguments, because they might refer to a subtype that is currently being loaded.
  • Replaced non-ascii character (micro) with ascii 'u' in Win32PrintService.java.
  • IKVM.Reflection: Bug fix. Resource Directory Entries must be sorted and names are case-insensitive.

Binaries available here: ikvmbin-0.46.0.3.zip

Sources: ikvmsrc-0.46.0.3.zip, openjdk6-b22-stripped.zip

Wednesday, 26 September 2012 08:16:30 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Monday, 17 September 2012
IKVM.NET 7.2 Release Candidate 1

The previous release candidate had a regression that caused custom attributes specified in the remap xml file not to be applied. This caused the build to fail on .NET 4.0.

Changes (relative to rc 0):

  • Updated version to 7.2.4630.1
  • Fixed build number in CommonAssemblyInfo.cs.in.
  • Fixed .NET 4.0 build issues.
  • Fixed map.xml custom attribute application regression.
  • Updated HOWTO.

Binaries available here: ikvmbin-7.2.4630.1.zip

Sources: ikvmsrc-7.2.4630.1.zip, openjdk-7u6-b24-stripped.zip

Monday, 17 September 2012 13:39:29 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Tuesday, 04 September 2012
IKVM.NET 7.2 Release Candidate 0

The first release candidate is available. Compared with the development snapshot some minor improvements to Object.getClass() and Class.getDeclaredField() instrinsics were made.

Changes (relative to IKVM.NET 7.1):

  • Integrated OpenJDK 7u6 b24.
  • Improved java.util.concurrent performance.
  • Removed org.omg.PortableInterceptor.UNKNOWN class, that is not part of [Open]JDK rt.jar.
  • Added ZipFile constructor that was added in Java 7.
  • Changed ikvmc to apply custom attribute annotations on annotation types to the corresponding custom attribute that is generated (and allow AttributeUsageAttribute to override the default AttributeUsageAttribute generated from the @Target annotation).
  • Added app.config files for executables to allow them to run on .NET 4.5 on Windows 8 without triggering the .NET 3.5 auto download.
  • Bug fixes.
  • Many IKVM.Reflection improvements.

Binaries available here: ikvmbin-7.2.4630.0.zip

Sources: ikvmsrc-7.2.4630.0.zip, openjdk-7u6-b24-stripped.zip

Tuesday, 04 September 2012 15:39:29 (W. Europe Daylight Time, UTC+02:00)  #    Comments [5]
# Friday, 31 August 2012
New Development Snapshot

I've integrated OpenJDK 7u6. The 7u7 security update is not included (as IKVM.NET is not suitable for running untrusted Java code anyway).

One divergence from 7u6 of note is that the new string hashing (used to protect against DoS attacks by intentionally causing hash collisions) has not been implemented. Instead the .NET String.GetHashCode() method is used for the alternative hash code. If DoS protection is required, .NET 4.5 should be used and randomized string hashing should be enabled.

Next stop the release candidate.

Changes:

  • Merged OpenJDK 7u6 b24.
  • Add support for running with headless awt toolkit. Fix for #3552089.
  • Fix a ClassCastException in printerJob.defaultPage() if the default paper format is not a standard paper format. This can occur with label printer.
  • Stop using ConstructorBuilder (always use MethodBuilder).
  • Remove usage of AssemblyName.ReferenceMatchesDefinition() because it is broken on .NET and not implemented on Mono.
  • Apply custom attribute annotations on annotation types to the corresponding custom attribute that is generated (and allow AttributeUsageAttribute to override the default AttributeUsageAttribute generated from the @Target annotation).
  • Fixed InternalsVisibleToAttribute handling to take the public key into account as well.
  • Win32 print service fixes.
  • Optimized String.valueOf(char).
  • Add app.config files for executables to allow them to run on .NET 4.5 on Windows 8 without triggering the .NET 3.5 auto download.
  • Fix Window.setIconImages(). Now all images are used. Before only the first image was used.
  • Disallow Unsafe.getUnsafe() from being called via reflection (for JDK compatibility).
  • Merged in security manager check to Font.createFont(int, File) from OpenJDK.
  • IKVM.Reflection: Bug fix. When enumerating virtual methods, we should only skip match actual base methods, not any method with the same signature.
  • IKVM.Reflection: Automatically add default constructor when necessary (using the same criteria as Ref.Emit).
  • IKVM.Reflection: Added API extension to wrap MethodInfo in a ConstructorInfo.

Binaries available here: ikvmbin-7.2.4626.zip

The stripped OpenJDK 7u6 b24 sources are available here: openjdk-7u6-b24-stripped.zip

Friday, 31 August 2012 13:43:50 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Tuesday, 24 July 2012
New Development Snapshot

I did some bytecode fuzzing and found and fixed a number of obscure bugs. Also fixed the bug reported here.

Changes:

  • Bug fix. If we encounter an invokedynamic in a method that has a jsr (which is always invalid because of class version rules), we need to throw a VerifyError.
  • Bug fix. If we encounter a jsr or ret instruction, we should throw a VerifyError (instead of NotImplementedException).
  • Bug fix. If a bytecode instruction refers to an invalid constant pool entry, MarkLinkRequiredConstantPoolItem should not throw an exception, but simply ignore the mark, the incorrect bytecode will be reported later during verification.
  • Bug fix. It is not valid to call TypeWrapper.IsInterfaceOrInterfaceArray on an UnloadableTypeWrapper.
  • Bug fix. There was a logic error in FindBaseMethods7() that caused LinkAndGetMethod() to be called if TryGetClassFileVersion() succeeded and the class version was greater than or equal to 51.
  • Bug fix. If a Java class extends a remapped .NET type (cli.System.Object or cli.System.Exception), we should correctly report the base class.
  • Bug fix. If a finally/fault handler contains reachable code before the handler's start index, the handler should branch to the handler start index.
  • Bug fix. After emitting a finally/fault handler block, we should emit the block leave stubs (even though you can't leave the block, they also emit the backward branch stubs).

Binaries available here: ikvmbin-7.2.4587.zip

Tuesday, 24 July 2012 08:12:29 (W. Europe Daylight Time, UTC+02:00)  #    Comments [0]
# Wednesday, 18 July 2012
New Development Snapshot

I've been working on IKVM.Reflection to fix some loose ends and add support for various .NET 4.5 features. I also managed to squeeze in some bug fixes for IKVM.NET itself and some improvements to the (experimental and disabled by default) MSIL optimizer. Finally, I added intrinsics for some sun.misc.Unsafe operations to make some of the java.util.concurrent classes more efficient.

Changes:

  • Bug fix. The interface fields exposed in the __Fields nested type should have a public field type.
  • Interface fields can always be marked as initonly and don't need final access stubs.
  • Disable AppDomain.ProcessExit hook to run shutdown hooks when running on Mono to workaround https://bugzilla.xamarin.com/show_bug.cgi?id=5650
  • Changed NoClassDefFoundError resulting from type initialization failure to be consistent with OpenJDK behavior.
  • Many improvements to the (disabled) MSIL optimizer.
  • Added intrinsics for (some usages of) Unsafe methods: putObject, putOrderedObject, putObjectVolatile, getObjectVolatile, getObject, compareAndSwapObject.
  • Marked String.compareTo(Object) as bridge method.
  • Remove org.omg.PortableInterceptor.UNKNOWN class, that is not part of [Open]JDK rt.jar.
  • Add ZipFile constructor that was added in Java 7.
  • Deprecated the ikvmstub -serialver option and added a -japi option instead that also adds non-public interfaces and members. Also added a hack to fix the fact that String instance methods were all marked as deprecated.
  • Internal stub generator now reproduces exact class modifier bits.
  • Unused class modifier bits are now properly masked and returned.
  • Non-abstract interfaces now properly return ACC_ABSTRACT modifier.
  • IKVM.Reflection: Added .NET 4.5 ModuleBuilder APIs GetMethodToken(MethodInfo, IEnumerable) and GetConstructorToken(MethodInfo, IEnumerable).
  • IKVM.Reflection: Added API extensions ModuleBuilder.__GetMethodToken() and ModuleBuilder.__GetConstructorToken().
  • IKVM.Reflection: Bug fix. SignatureHelper.AddArguments() should accept a null reference for arguments parameter.
  • IKVM.Reflection: Bug fix. SignatureHelper.GetMethodSigHelper(Module, Type, Type[]) should accept null reference for parameterTypes argument.
  • IKVM.Reflection: Bug fix. SignatureHelper.AddArguments(Type[], Type[][], Type[][]) should accept null references for requiredCustomModifiers and optionalCustomModifiers.
  • IKVM.Reflection: Bug fix. SignatureHelper.AddSentinel() should not affect the calling convention.
  • IKVM.Reflection: Simplified SignatureHelper implementation to make it more compatible with .NET and more efficient.
  • IKVM.Reflection: Added .NET 4.5 AssemblyName.ContentType property and ContentType=WindowsRuntime in AssemblyName.
  • IKVM.Reflection: Bug fix. ModuleBuilder.ResolveMethod() should return ConstructorInfo for constructors.
  • IKVM.Reflection: Made MethodSpec handling more consistent with MemberRef handling. This avoids the need for the caching the MethodInfo to token mappings (which leaks memory, because generic method instances are not canonicalized).
  • IKVM.Reflection: Removed unnecessary (and memory leaking) member ref caching level.
  • IKVM.Reflection: Explicitly disallow modifying a method signature after it has been used.
  • IKVM.Reflection: Added experimental support for generating Windows Runtime (.winmd) assemblies.
  • IKVM.Reflection: Added missing DefineResource() APIs to ModuleBuilder and AssemblyBuilder.
  • IKVM.Reflection: Fixed regression. Type.GetConstructor() should also return the class constructor. This also fixes Type.TypeInitializer.
  • IKVM.Reflection: Updated Assembly.CreateQualifiedName() to be compatible with current .NET versions.
  • IKVM.Reflection: Added new .NET 4.5 API Type.IsConstructedGenericType.
  • IKVM.Reflection: Added co-/contra-variance support to Type.IsAssignableFrom().
  • IKVM.Reflection: Added support for using the .NETCore v4.5 aka Metro profile mscorlib.dll.
  • IKVM.Reflection: Ignore HasFieldMarshal attribute and always return the pseudo custom attribute if a FieldMarshal record exists. This is similar to .NET reflection.
  • IKVM.Reflection: If a FieldLayout record exists, always return the pseudo custom attribute FieldOffset, regardless of the declaring type's layout.
  • IKVM.Reflection: Added new API [Field|Parameter]Info.__TryGetFieldMarshal().
  • IKVM.Reflection: Added new API FieldInfo.__TryGetFieldOffset().
  • IKVM.Reflection: Keep track of whether a ModuleBuilder has been saved (and only allow it to be saved once).
  • IKVM.Reflection: Fixed various builders to throw NotImplementedException (like .NET) when getting custom attributes before the type has been baked.
  • IKVM.Reflection: Fixed various builders to properly return custom attributes after the module has been saved.
  • IKVM.Reflection: Bug fix. FieldBuilder.GetRawConstantValue() didn't work after saving the module.
  • IKVM.Reflection: Bug fix. MethodInfo should return PreserveSigAttribute pseudo custom attribute if MethodImplAttributes.PreserveSig is set.
  • IKVM.Reflection: Added new API MethodInfo.__TryGetImplMap().
  • IKVM.Reflection: Changed DllImportAttribute synthesis to always include CharSet, BestFitMapping and ThrowOnUnmappableChar to be compatible with .NET. Now that we have __TryGetImplMap() we don't need to distinguish anymore between not set and set to the default value.
  • IKVM.Reflection: Added .NET 4.5 API CustomAttributeData.AttributeType property.
  • IKVM.Reflection: Made MarshalAsAttribute synthesis more compatible with .NET by always setting ArraySubType, SizeParamIndex, SizeConst and SafeArraySubType properties.
  • IKVM.Reflection: Made CustomAttributeData.ToString() output more compatible with .NET (by "casting" enum values, except zero).
  • IKVM.Reflection: Fixed MarshalAsAttribute values. Use enum underlying values, instead of the enum values.
  • IKVM.Reflection: Added UniverseOptions.DisablePseudoCustomAttributeRetrieval to disable returning pseudo custom attributes.

Binaries available here: ikvmbin-7.2.4582.zip

Wednesday, 18 July 2012 08:35:08 (W. Europe Daylight Time, UTC+02:00)  #    Comments [2]