aromaa / managedclr

A really, really, really, really basic (and messy) implementation of C# runtime made in C# (For learning purposes)

Joni Aromaa 😻🐱🐈

Nerd with glasses. A guy who primary writes C# and tries to understand the internals of CoreCLR. Likes the blocky game known as Minecraft ⛏ and loves building creative, complex and big software with performance in the mind. I may be seen around on all kinds of communities :)

I also like cats, if you didn't figure that out yet..

managedclr's Issues

Implement all IL instructions

There are few special IL instructions that most likely won't get implemented but keeping them all listed up to track their progress.

Currently implemented instructions are:

• add
• add.ovf
• add.ovf.un
• and
• arglist
• beq
• beq.s
• bge
• bge.s
• bge.un
• bge.un.s
• bgt
• bgt.s
• bgt.un
• bgt.un.s
• ble
• ble.s
• ble.un
• ble.un.s
• blt
• blt.s
• blt.un
• blt.un.s
• bne.un
• bne.un.s
• box
• br
• br.s
• break
• brfalse
• brfalse.s
• brinst
• brinst.s
• brnull
• brnull.s
• brtrue
• brtrue.s
• brzero
• brzero.s
• call
• calli
• callvirt
• castclass
• ceq
• cgt
• cgt.un
• ckfinite
• clt
• clt.un
• constrained
• conv.i
• conv.i1
• conv.i2
• conv.i4
• conv.i8
• conv.ovf.i
• conv.ovf.i.un
• conv.ovf.i1
• conv.ovf.i1.un
• conv.ovf.i2
• conv.ovf.i2.un
• conv.ovf.i4
• conv.ovf.i4.un
• conv.ovf.i8
• conv.ovf.i8.un
• conv.ovf.u
• conv.ovf.u.un
• conv.ovf.u1
• conv.ovf.u1.un
• conv.ovf.u2
• conv.ovf.u2.un
• conv.ovf.u4
• conv.ovf.u4.un
• conv.ovf.u8
• conv.ovf.u8.un
• conv.r.un
• conv.r4
• conv.r8
• conv.u
• conv.u1
• conv.u2
• conv.u4
• conv.u8
• cpblk
• cpobj
• div
• div.un
• dup
• endfault
• endfilter
• endfinally
• initblk
• initobj
  • Basic support for value types
    • Reserve stack space
    • Zero-init
  • Basic support for reference types
• isinst
• jmp
• ldarg
• ldarg.0
• ldarg.1
• ldarg.2
• ldarg.3
• ldarg.s
• ldarga
• ldarga.s
• ldc.i4
• ldc.i4.0
• ldc.i4.1
• ldc.i4.2
• ldc.i4.3
• ldc.i4.4
• ldc.i4.5
• ldc.i4.6
• ldc.i4.7
• ldc.i4.8
• ldc.i4.m1
• ldc.i4.M1
• ldc.i4.s
• ldc.i8
• ldc.r4
• ldc.r8
• ldelem
• ldelem.i
• ldelem.i1
• ldelem.i2
• ldelem.i4
• ldelem.i8
• ldelem.r4
• ldelem.r8
• ldelem.ref
• ldelem.u1
• ldelem.u2
• ldelem.u4
• ldelem.u8
• ldelema
• ldfld
  • Value types
  • Reference types
• ldflda
• ldftn
• ldind.i
• ldind.i1
• ldind.i2
• ldind.i4
• ldind.i8
• ldind.r4
• ldind.r8
• ldind.ref
• ldind.u1
• ldind.u2
• ldind.u4
• ldind.u8
• ldlen
• ldloc
• ldloc.0
• ldloc.1
• ldloc.2
• ldloc.3
• ldloc.s
• ldloca
• ldloca.s
• ldnull
• ldobj
• ldsfld
• ldsflda
• ldstr
• ldtoken
• ldvirtftn
• leave
• leave.s
• localloc
• mkrefany
• mul
• mul.ovf
• mul.ovf.un
• neg
• newarr
• newobj
• no
• nop
• not
• or
• pop
• readonly.
• refanytype
• refanyval
• rem
• rem.un
• ret
• rethrow
• shl
• shr
• shr.un
• sizeof
• starg
• starg.s
• stelem
• stelem.i
• stelem.i1
• stelem.i2
• stelem.i4
• stelem.i8
• stelem.r4
• stelem.r8
• stelem.ref
• stfld
  • Value types
  • Reference types
• stind.i
• stind.i1
• stind.i2
• stind.i4
• stind.i8
• stind.r4
• stind.r8
• stind.ref
• stloc
• stloc.0
• stloc.1
• stloc.2
• stloc.3
• stloc.s
• stobj
• stsfld
• sub
• sub.ovf
• sub.ovf.un
• switch
• tail.
• throw
• unaligned
• unbox
• unbox.any
• volatile.
• xor

Type loader

The JIT needs to know type layout to be able to generate code for instance objects or structs.

• Type layout
  • Non-generic
  • Generic
  • Distinct between blittable and non-blittable fields
• Type methods
  • Non-generic
  • Generic

Support instance objects

In order to support basic instance objects we first need a type system and basic GC.

• Type loader (Tracked by #3)
• Basic GC (Tracked by #4)

Basic GC

The goal for the first basic GC is able to ask for allocation space, the other tasks are for more general

• GC can allocate memory
• GC knows which objects are reachable
  • GC can track objects fields
  • GC can solve circular dependency
• GC is able to free memory

Support value types

The value types mostly are only accessed on the stack but we also need to support boxing.

• Type loader (Tracked by #3)
• GC can track reference type fields
• Boxing

Make JIT compile methods only on demand

Currently we are recursively compiling methods as we come across them on IL. This should be pretty straight forward to change by introducing indirection to calls.

Support other platforms

Currently there is only Windows support but I would like to add Linux and macOS support too, these should be fairly simple to do.

• Windows
• Linux
  • Ubuntu
• MacOS