Add field pointer handle (#113)

WoofWare.PawPrint/BasicCliType.fs

@@ -41,6 +41,7 @@ type ManagedPointerSource =
     | Argument of sourceThread : ThreadId * methodFrame : int * whichVar : uint16
     | Heap of ManagedHeapAddress
     | ArrayIndex of arr : ManagedHeapAddress * index : int
+    | Field of ManagedPointerSource * fieldName : string
     | Null
 
     override this.ToString () =
@@ -52,6 +53,7 @@ type ManagedPointerSource =
         | ManagedPointerSource.Argument (source, method, var) ->
             $"<argument %i{var} in method frame %i{method} of thread %O{source}>"
         | ManagedPointerSource.ArrayIndex (arr, index) -> $"<index %i{index} of array %O{arr}>"
+        | ManagedPointerSource.Field (source, name) -> $"<field %s{name} of %O{source}>"
 
 [<RequireQualifiedAccess>]
 type UnsignedNativeIntSource =
@@ -117,6 +119,7 @@ type CliNumericType =
 type CliRuntimePointerSource =
     | LocalVariable of sourceThread : ThreadId * methodFrame : int * whichVar : uint16
     | Argument of sourceThread : ThreadId * methodFrame : int * whichVar : uint16
+    | Field of source : CliRuntimePointerSource * fieldName : string
     | Heap of ManagedHeapAddress
     | ArrayIndex of arr : ManagedHeapAddress * index : int
     | Null
@@ -132,6 +135,10 @@ module CliRuntimePointerSource =
         | ManagedPointerSource.Heap managedHeapAddress -> CliRuntimePointerSource.Heap managedHeapAddress
         | ManagedPointerSource.Null -> CliRuntimePointerSource.Null
         | ManagedPointerSource.ArrayIndex (arr, ind) -> CliRuntimePointerSource.ArrayIndex (arr, ind)
+        | ManagedPointerSource.Field (a, ind) ->
+            let a = ofManagedPointerSource a
+            CliRuntimePointerSource.Field (a, ind)
+
 
 type CliRuntimePointer =
     | Unmanaged of int64

WoofWare.PawPrint/EvalStack.fs

@@ -319,6 +319,9 @@ module EvalStackValue =
                     |> EvalStackValue.ManagedPointer
                 | CliRuntimePointerSource.Heap addr -> EvalStackValue.ObjectRef addr
                 | CliRuntimePointerSource.Null -> EvalStackValue.ManagedPointer ManagedPointerSource.Null
+                | CliRuntimePointerSource.Field (source, fieldName) ->
+                    ManagedPointerSource.Field (failwith "TODO", fieldName)
+                    |> EvalStackValue.ManagedPointer
         | CliType.ValueType fields ->
             // TODO: this is a bit dubious; we're being a bit sloppy with possibly-overlapping fields here
             fields.Fields

WoofWare.PawPrint/EvalStackValueComparisons.fs

@@ -169,6 +169,7 @@ module EvalStackValueComparisons =
             match src with
             | ManagedPointerSource.Heap src -> src = var1
             | ManagedPointerSource.Null -> false
+            | ManagedPointerSource.Field _
             | ManagedPointerSource.LocalVariable _
             | ManagedPointerSource.Argument _ -> false
             | ManagedPointerSource.ArrayIndex (arr, index) -> failwith "todo"

WoofWare.PawPrint/ExternImplementations/System.Threading.Monitor.fs

@@ -88,6 +88,7 @@ module System_Threading_Monitor =
                         failwith "not really expecting to *edit* an argument..."
                     | ManagedPointerSource.Heap addr -> failwith "todo: managed heap"
                     | ManagedPointerSource.ArrayIndex _ -> failwith "todo: array index"
+                    | ManagedPointerSource.Field (managedPointerSource, fieldName) -> failwith "todo"
 
                 (state, WhatWeDid.Executed) |> ExecutionResult.Stepped
 

WoofWare.PawPrint/IlMachineState.fs

@@ -1602,6 +1602,12 @@ module IlMachineState =
             state.ThreadState.[sourceThread].MethodStates.[methodFrame].Arguments.[int<uint16> whichVar]
         | ManagedPointerSource.Heap addr -> failwith "todo"
         | ManagedPointerSource.ArrayIndex (arr, index) -> getArrayValue arr index state
+        | ManagedPointerSource.Field (addr, name) ->
+            let obj = dereferencePointer state addr
+
+            match obj with
+            | CliType.ValueType vt -> vt |> CliValueType.DereferenceField name
+            | v -> failwith $"could not find field {name} on object {v}"
 
     let lookupTypeDefn
         (baseClassTypes : BaseClassTypes<DumpedAssembly>)

WoofWare.PawPrint/IlMachineStateExecution.fs

@@ -62,6 +62,7 @@ module IlMachineStateExecution =
                 state, o.ConcreteType
             | ManagedPointerSource.ArrayIndex (arr, index) -> failwith "todo"
             | ManagedPointerSource.Null -> failwith "todo"
+            | ManagedPointerSource.Field (managedPointerSource, fieldName) -> failwith "todo"
         | EvalStackValue.ObjectRef addr ->
             let o = ManagedHeap.get addr state.ManagedHeap
             state, o.ConcreteType

WoofWare.PawPrint/Intrinsics.fs

@@ -112,6 +112,7 @@ module Intrinsics =
                         CliRuntimePointer.Managed (CliRuntimePointerSource.Heap managedHeapAddress)
                     | ManagedPointerSource.Null -> failwith "todo"
                     | ManagedPointerSource.ArrayIndex _ -> failwith "TODO"
+                    | ManagedPointerSource.Field _ -> failwith "TODO"
                 | x -> failwith $"TODO: Unsafe.AsPointer(%O{x})"
 
             IlMachineState.pushToEvalStack (CliType.RuntimePointer toPush) currentThread state

WoofWare.PawPrint/NullaryIlOp.fs

@@ -37,19 +37,6 @@ module NullaryIlOp =
         | LdindR4 -> CliType.Numeric (CliNumericType.Float32 0.0f)
         | LdindR8 -> CliType.Numeric (CliNumericType.Float64 0.0)
 
-    /// Retrieve a value from a pointer
-    let private loadFromPointerSource (state : IlMachineState) (src : ManagedPointerSource) : CliType =
-        match src with
-        | ManagedPointerSource.Null -> failwith "unexpected null pointer in Ldind operation"
-        | ManagedPointerSource.Argument (sourceThread, methodFrame, whichVar) ->
-            state.ThreadState.[sourceThread].MethodStates.[methodFrame].Arguments.[int<uint16> whichVar]
-        | ManagedPointerSource.LocalVariable (sourceThread, methodFrame, whichVar) ->
-            state.ThreadState.[sourceThread].MethodStates.[methodFrame].LocalVariables.[int<uint16> whichVar]
-        | ManagedPointerSource.Heap managedHeapAddress -> failwith "TODO: Heap pointer dereferencing not implemented"
-        | ManagedPointerSource.ArrayIndex (arr, index) ->
-            let arr = state.ManagedHeap.Arrays.[arr]
-            arr.Elements.[index]
-
     // Unified Ldind implementation
     let private executeLdind
         (targetType : LdindTargetType)
@@ -61,7 +48,7 @@ module NullaryIlOp =
 
         let loadedValue =
             match popped with
-            | EvalStackValue.ManagedPointer src -> loadFromPointerSource state src
+            | EvalStackValue.ManagedPointer src -> IlMachineState.dereferencePointer state src
             | EvalStackValue.NativeInt nativeIntSource ->
                 failwith $"TODO: Native int pointer dereferencing not implemented for {targetType}"
             | EvalStackValue.ObjectRef managedHeapAddress ->
@@ -125,6 +112,7 @@ module NullaryIlOp =
                 }
             | ManagedPointerSource.Heap managedHeapAddress -> failwith "todo"
             | ManagedPointerSource.ArrayIndex _ -> failwith "todo"
+            | ManagedPointerSource.Field (managedPointerSource, fieldName) -> failwith "todo"
         | EvalStackValue.ObjectRef managedHeapAddress -> failwith "todo"
 
     let internal ldElem
@@ -892,16 +880,7 @@ module NullaryIlOp =
 
             let referenced =
                 match addr with
-                | EvalStackValue.ManagedPointer src ->
-                    match src with
-                    | ManagedPointerSource.Null -> failwith "TODO: throw NRE"
-                    | ManagedPointerSource.LocalVariable (sourceThread, methodFrame, whichVar) ->
-                        state.ThreadState.[sourceThread].MethodStates.[methodFrame].LocalVariables
-                            .[int<uint16> whichVar]
-                    | ManagedPointerSource.Argument (sourceThread, methodFrame, whichVar) ->
-                        state.ThreadState.[sourceThread].MethodStates.[methodFrame].Arguments.[int<uint16> whichVar]
-                    | ManagedPointerSource.Heap managedHeapAddress -> failwith "todo"
-                    | ManagedPointerSource.ArrayIndex _ -> failwith "todo"
+                | EvalStackValue.ManagedPointer src -> IlMachineState.dereferencePointer state src
                 | a -> failwith $"TODO: {a}"
 
             let state =
@@ -929,6 +908,7 @@ module NullaryIlOp =
                             arr
                             (EvalStackValue.toCliTypeCoerced (CliType.ObjectRef None) value)
                             index
+                    | ManagedPointerSource.Field _ -> failwith "TODO"
                 | addr -> failwith $"TODO: {addr}"
 
             let state = state |> IlMachineState.advanceProgramCounter currentThread

WoofWare.PawPrint/UnaryMetadataIlOp.fs

@@ -601,6 +601,8 @@ module internal UnaryMetadataIlOp =
                         |> CliType.withFieldSet field.Name valueToStore
 
                     state |> IlMachineState.setArrayValue arr newValue index
+                | EvalStackValue.ManagedPointer (ManagedPointerSource.Field (managedPointerSource, fieldName)) ->
+                    failwith "todo"
                 | EvalStackValue.UserDefinedValueType _ -> failwith "todo"
 
             state
@@ -768,6 +770,8 @@ module internal UnaryMetadataIlOp =
                     IlMachineState.pushToEvalStack currentValue thread state
                 | EvalStackValue.ManagedPointer ManagedPointerSource.Null ->
                     failwith "TODO: raise NullReferenceException"
+                | EvalStackValue.ManagedPointer (ManagedPointerSource.Field _) ->
+                    failwith "TODO: get a field on a field ptr"
                 | EvalStackValue.UserDefinedValueType vt ->
                     let result = vt |> EvalStackValueUserType.DereferenceField field.Name
                     IlMachineState.pushToEvalStack' result thread state