Finish initialising class of the main method before execution (#59)

WoofWare.PawPrint.Domain/Assembly.fs

@@ -527,7 +527,7 @@ module DumpedAssembly =
         (baseTypeInfo : BaseTypeInfo option)
         : ResolvedBaseType
         =
-        let rec go (baseType : BaseTypeInfo option) =
+        let rec go (source : AssemblyName) (baseType : BaseTypeInfo option) =
             match baseType with
             | Some (BaseTypeInfo.TypeRef r) ->
                 let assy = loadedAssemblies.[source.FullName]
@@ -539,7 +539,7 @@ module DumpedAssembly =
                 | TypeResolutionResult.Resolved (assy, typeInfo) ->
                     match TypeInfo.isBaseType bct _.Name assy.Name typeInfo.TypeDefHandle with
                     | Some v -> v
-                    | None -> go typeInfo.BaseType
+                    | None -> go assy.Name typeInfo.BaseType
             | Some (BaseTypeInfo.ForeignAssemblyType (assy, ty)) ->
                 let assy = loadedAssemblies.[assy.FullName]
 
@@ -547,7 +547,7 @@ module DumpedAssembly =
                 | Some v -> v
                 | None ->
                     let ty = assy.TypeDefs.[ty]
-                    go ty.BaseType
+                    go assy.Name ty.BaseType
             | Some (BaseTypeInfo.TypeSpec _) -> failwith "TODO"
             | Some (BaseTypeInfo.TypeDef h) ->
                 let assy = loadedAssemblies.[source.FullName]
@@ -556,7 +556,7 @@ module DumpedAssembly =
                 | Some v -> v
                 | None ->
                     let ty = assy.TypeDefs.[h]
-                    go ty.BaseType
+                    go assy.Name ty.BaseType
             | None -> ResolvedBaseType.Object
 
-        go baseTypeInfo
+        go source baseTypeInfo

WoofWare.PawPrint.Domain/MethodInfo.fs

@@ -142,6 +142,17 @@ type MethodInstructions =
         ExceptionRegions : ImmutableArray<ExceptionRegion>
     }
 
+    static member OnlyRet : MethodInstructions =
+        let op = IlOp.Nullary NullaryIlOp.Ret
+
+        {
+            Instructions = [ op, 0 ]
+            Locations = Map.empty |> Map.add 0 op
+            LocalsInit = false
+            LocalVars = None
+            ExceptionRegions = ImmutableArray.Empty
+        }
+
 /// <summary>
 /// Represents detailed information about a method in a .NET assembly.
 /// This is a strongly-typed representation of MethodDefinition from System.Reflection.Metadata.

WoofWare.PawPrint/Program.fs

@@ -40,6 +40,29 @@ module Program =
 
         arrayAllocation, state
 
+    let rec pumpToReturn
+        (loggerFactory : ILoggerFactory)
+        (logger : ILogger)
+        (baseClassTypes : BaseClassTypes<DumpedAssembly>)
+        impls
+        (mainThread : ThreadId)
+        (state : IlMachineState)
+        : IlMachineState * ThreadId
+        =
+        match AbstractMachine.executeOneStep loggerFactory impls baseClassTypes state mainThread with
+        | ExecutionResult.Terminated (state, terminatingThread) -> state, terminatingThread
+        | ExecutionResult.Stepped (state', whatWeDid) ->
+
+        match whatWeDid with
+        | WhatWeDid.Executed ->
+            logger.LogInformation $"Executed one step; active assembly: {state'.ActiveAssembly(mainThread).Name.Name}"
+        | WhatWeDid.SuspendedForClassInit ->
+            logger.LogInformation "Suspended execution of current method for class initialisation."
+        | WhatWeDid.BlockedOnClassInit threadBlockingUs ->
+            logger.LogInformation "Unable to execute because class has not yet initialised."
+
+        pumpToReturn loggerFactory logger baseClassTypes impls mainThread state'
+
     /// Returns the abstract machine's state at the end of execution, together with the thread which
     /// caused execution to end.
     let run
@@ -83,7 +106,7 @@ module Program =
                     dumped
                     // pretend there are no instructions, so we avoid preparing anything
                     { mainMethod with
-                        Instructions = None
+                        Instructions = Some MethodInstructions.OnlyRet
                     }
                     None
                     (ImmutableArray.CreateRange [ CliType.ObjectRef None ])
@@ -153,7 +176,14 @@ module Program =
         | TypeDefn.PrimitiveType PrimitiveType.Int32 -> ()
         | _ -> failwith "Main method must return int32; other types not currently supported"
 
-        // Now that BCL initialisation has taken place, overwrite the main thread completely.
+        // We might be in the middle of class construction. Pump the static constructors to completion.
+        // We haven't yet entered the main method!
+
+        let state, _ =
+            pumpToReturn loggerFactory logger baseClassTypes impls mainThread state
+
+        // Now that BCL initialisation has taken place and the user-code classes are constructed,
+        // overwrite the main thread completely.
         let methodState =
             match
                 MethodState.Empty
@@ -171,27 +201,22 @@ module Program =
         let threadState =
             { state.ThreadState.[mainThread] with
                 MethodStates = ImmutableArray.Create methodState
+                ActiveMethodState = 0
             }
 
-        let state =
+        let state, init =
             { state with
                 ThreadState = state.ThreadState |> Map.add mainThread threadState
             }
+            |> IlMachineState.ensureTypeInitialised
+                loggerFactory
+                baseClassTypes
+                mainThread
+                methodState.ExecutingMethod.DeclaringType
 
-        let rec go (state : IlMachineState) =
-            match AbstractMachine.executeOneStep loggerFactory impls baseClassTypes state mainThread with
-            | ExecutionResult.Terminated (state, terminatingThread) -> state, terminatingThread
-            | ExecutionResult.Stepped (state', whatWeDid) ->
+        match init with
+        | WhatWeDid.SuspendedForClassInit -> failwith "TODO: suspended for class init"
+        | WhatWeDid.BlockedOnClassInit _ -> failwith "logic error: surely this thread can't be blocked on class init"
+        | WhatWeDid.Executed -> ()
 
-            match whatWeDid with
-            | WhatWeDid.Executed ->
-                logger.LogInformation
-                    $"Executed one step; active assembly: {state'.ActiveAssembly(mainThread).Name.Name}"
-            | WhatWeDid.SuspendedForClassInit ->
-                logger.LogInformation "Suspended execution of current method for class initialisation."
-            | WhatWeDid.BlockedOnClassInit threadBlockingUs ->
-                logger.LogInformation "Unable to execute because class has not yet initialised."
-
-            go state'
-
-        go state
+        pumpToReturn loggerFactory logger baseClassTypes impls mainThread state