Metadata ordering issues

Some of the metadata tables have requirements on sort order. ILPack doesn’t currently ensure these rules aren’t violated. The main two that seem to be causing issues is the order of the generic parameters table and the interface map.

These are difficult to reproduce in the unit tests because the ordering and interleaving of things can be affected by other things in the project. Here’s how to reproduce both issues in Sandbox.

Add the following to SandboxSubject\MyClass.cs, just below MyClass:

public class GPOrder1
{
    public void Function1<T>()
    {
    }
    public void Function2<T>()
    {
    }
}

public class GPOrder2<T>
{
}

Result:

Metadata table GenericParam not sorted.
   at System.Reflection.Throw.InvalidOperation_TableNotSorted(TableIndex tableIndex)
   at System.Reflection.Metadata.Ecma335.MetadataBuilder.ValidateGenericParamTable()
   at System.Reflection.Metadata.Ecma335.MetadataBuilder.ValidateOrder()
   at System.Reflection.Metadata.Ecma335.MetadataRootBuilder.Serialize(BlobBuilder builder, Int32 methodBodyStreamRva, Int32 mappedFieldDataStreamRva)

For the interface map problem, remove the above code and add this instead:

interface Itf1
{
}
interface Itf2
{
}
class MyImpl : Itf2, Itf1
{
}

Result:

Metadata table InterfaceImpl not sorted.
   at System.Reflection.Throw.InvalidOperation_TableNotSorted(TableIndex tableIndex)
   at System.Reflection.Metadata.Ecma335.MetadataBuilder.ValidateInterfaceImplTable()
   at System.Reflection.Metadata.Ecma335.MetadataBuilder.ValidateOrder()
   at System.Reflection.Metadata.Ecma335.MetadataRootBuilder.Serialize(BlobBuilder builder, Int32 methodBodyStreamRva, Int32 mappedFieldDataStreamRva)

[vermorel]

@SvenGroot Thanks a lot for spotting a solution! have extended the unit tests as well, and indeed, we do increase the coverage with your fix.

CC @per-samuelsson @TalAloni

[OlegRa]

@vermorel I’ve tested this and can confirm that the original problem is already solved so we can close this issue.