Merge pull request #15164 from dotnet/merges/main-to-release/dev17.7

Merge main to release/dev17.7

src/Compiler/AbstractIL/ilread.fs

@@ -228,7 +228,7 @@ type WeakByteFile(fileName: string, chunk: (int * int) option) =
     let fileStamp = FileSystem.GetLastWriteTimeShim fileName
 
     /// The weak handle to the bytes for the file
-    let weakBytes = WeakReference<byte[]>(null)
+    let weakBytes = WeakReference<byte[] MaybeNull>(null)
 
     member _.FileName = fileName
 
@@ -254,7 +254,7 @@ type WeakByteFile(fileName: string, chunk: (int * int) option) =
 
                     weakBytes.SetTarget bytes
 
-                tg
+                nonNull tg
 
             ByteMemory.FromArray(strongBytes).AsReadOnly()
 
@@ -941,10 +941,11 @@ let mkCacheInt32 lowMem _inbase _nm _sz =
         fun f (idx: int32) ->
             let cache =
                 match cache with
-                | null -> cache <- ConcurrentDictionary<int32, _>(Environment.ProcessorCount, 11)
-                | _ -> ()
-
-                cache
+                | Null ->
+                    let v = ConcurrentDictionary<int32, _>(Environment.ProcessorCount, 11)
+                    cache <- v
+                    v
+                | NonNull v -> v
 
             match cache.TryGetValue idx with
             | true, res ->
@@ -969,10 +970,11 @@ let mkCacheGeneric lowMem _inbase _nm _sz =
         fun f (idx: 'T) ->
             let cache =
                 match cache with
-                | null -> cache <- ConcurrentDictionary<_, _>(Environment.ProcessorCount, 11 (* sz: int *) )
-                | _ -> ()
-
-                cache
+                | Null ->
+                    let v = ConcurrentDictionary<_, _>(Environment.ProcessorCount, 11 (* sz: int *) )
+                    cache <- v
+                    v
+                | NonNull v -> v
 
             match cache.TryGetValue idx with
             | true, v ->

src/Compiler/AbstractIL/ilreflect.fs

@@ -265,7 +265,7 @@ type TypeBuilder with
         let t = typB.CreateTypeAndLog()
 
         let m =
-            if t <> null then
+            if box t <> null then
                 t.GetMethod(nm, (args |> Seq.map (fun x -> x.GetType()) |> Seq.toArray))
             else
                 null
@@ -546,10 +546,10 @@ let emEnv0 =
         delayedFieldInits = []
     }
 
-let envBindTypeRef emEnv (tref: ILTypeRef) (typT, typB, typeDef) =
+let envBindTypeRef emEnv (tref: ILTypeRef) (typT: System.Type MaybeNull, typB, typeDef) =
     match typT with
-    | null -> failwithf "binding null type in envBindTypeRef: %s\n" tref.Name
-    | _ ->
+    | Null -> failwithf "binding null type in envBindTypeRef: %s\n" tref.Name
+    | NonNull typT ->
         { emEnv with
             emTypMap = Zmap.add tref (typT, typB, typeDef, None) emEnv.emTypMap
         }
@@ -1018,7 +1018,7 @@ let queryableTypeGetMethod cenv emEnv parentT (mref: ILMethodRef) : MethodInfo =
                     cconv ||| BindingFlags.Public ||| BindingFlags.NonPublic,
                     null,
                     argTs,
-                    (null: ParameterModifier[])
+                    (null: ParameterModifier[] MaybeNull)
                 )
             // This can fail if there is an ambiguity w.r.t. return type
             with _ ->
@@ -1102,14 +1102,14 @@ let queryableTypeGetConstructor cenv emEnv (parentT: Type) (mref: ILMethodRef) =
         parentT.GetConstructor(BindingFlags.Public ||| BindingFlags.NonPublic ||| BindingFlags.Instance, null, reqArgTs, null)
 
     match res with
-    | null ->
+    | Null ->
         error (
             Error(
                 FSComp.SR.itemNotFoundInTypeDuringDynamicCodeGen ("constructor", mref.Name, parentT.FullName, parentT.Assembly.FullName),
                 range0
             )
         )
-    | _ -> res
+    | NonNull res -> res
 
 let nonQueryableTypeGetConstructor (parentTI: Type) (consInfo: ConstructorInfo) : ConstructorInfo MaybeNull =
     if parentTI.IsGenericType then

src/Compiler/Checking/CheckExpressions.fs

@@ -4332,7 +4332,7 @@ and TcTypeOrMeasure kindOpt (cenv: cenv) newOk checkConstraints occ (iwsam: Warn
         TcLongIdentType kindOpt cenv newOk checkConstraints occ iwsam env tpenv synLongId
 
     | MultiDimensionArrayType (rank, elemTy, m) ->
-        TcElementType cenv newOk checkConstraints occ env tpenv rank elemTy m
+        TcArrayType cenv newOk checkConstraints occ env tpenv rank elemTy m
 
     | SynType.App (StripParenTypes (SynType.LongIdent longId), _, args, _, _, postfix, m) ->
         TcLongIdentAppType kindOpt cenv newOk checkConstraints occ iwsam env tpenv longId postfix args m
@@ -4353,7 +4353,7 @@ and TcTypeOrMeasure kindOpt (cenv: cenv) newOk checkConstraints occ (iwsam: Warn
         TcFunctionType cenv newOk checkConstraints occ env tpenv domainTy resultTy
 
     | SynType.Array (rank , elemTy, m) ->
-        TcElementType cenv newOk checkConstraints occ env tpenv rank elemTy m
+        TcArrayType cenv newOk checkConstraints occ env tpenv rank elemTy m
 
     | SynType.Var (tp, _) ->
         TcTypeParameter kindOpt cenv env newOk tpenv tp
@@ -4521,7 +4521,7 @@ and TcFunctionType (cenv: cenv) newOk checkConstraints occ env tpenv domainTy re
     let tyR = mkFunTy g domainTyR resultTyR
     tyR, tpenv
 
-and TcElementType (cenv: cenv) newOk checkConstraints occ env tpenv rank elemTy m =
+and TcArrayType (cenv: cenv) newOk checkConstraints occ env tpenv rank elemTy m =
     let g = cenv.g
     let elemTy, tpenv = TcTypeAndRecover cenv newOk checkConstraints occ WarnOnIWSAM.Yes env tpenv elemTy
     let tyR = mkArrayTy g rank elemTy m
@@ -5339,8 +5339,8 @@ and TcExprUndelayedNoType (cenv: cenv) env tpenv synExpr =
     let expr, tpenv = TcExprUndelayed cenv (MustEqual overallTy) env tpenv synExpr
     expr, overallTy, tpenv
 
-/// Process a leaf construct where the actual type (or an approximation of it such as 'list<_>'
-/// or 'array<_>') is already sufficiently pre-known, and the information in the overall type
+/// Process a leaf construct where the actual type (or an approximation of it such as '_ list'
+/// or '_ array') is already sufficiently pre-known, and the information in the overall type
 /// can be eagerly propagated into the actual type (UnifyOverallType), including pre-calculating
 /// any type-directed conversion. This must mean that types extracted when processing the expression are not
 /// considered in determining any type-directed conversion. 

src/Compiler/Checking/ConstraintSolver.fs

@@ -1203,7 +1203,9 @@ and SolveTypeEqualsType (csenv: ConstraintSolverEnv) ndeep m2 (trace: OptionalTr
         if not (typarsAEquiv g aenv tps1 tps2) then localAbortD else
         SolveTypeEqualsTypeKeepAbbrevs csenv ndeep m2 trace bodyTy1 bodyTy2 
 
-    | TType_ucase (uc1, l1), TType_ucase (uc2, l2) when g.unionCaseRefEq uc1 uc2  -> SolveTypeEqualsTypeEqns csenv ndeep m2 trace None l1 l2
+    | TType_ucase (uc1, l1), TType_ucase (uc2, l2) when g.unionCaseRefEq uc1 uc2 ->
+        SolveTypeEqualsTypeEqns csenv ndeep m2 trace None l1 l2
+
     | _  -> localAbortD
 
 and SolveTypeEqualsTypeKeepAbbrevs csenv ndeep m2 trace ty1 ty2 =

src/Compiler/Checking/MethodCalls.fs

@@ -1067,7 +1067,7 @@ let MakeMethInfoCall (amap: ImportMap) m (minfo: MethInfo) minst args staticTyOp
         let isProp = false // not necessarily correct, but this is only used post-creflect where this flag is irrelevant 
         let ilMethodRef = Import.ImportProvidedMethodBaseAsILMethodRef amap m mi
         let isConstructor = mi.PUntaint((fun c -> c.IsConstructor), m)
-        let isStruct = mi.PUntaint((fun c -> c.DeclaringType.IsValueType), m)
+        let isStruct = mi.PUntaint((fun c -> (nonNull<ProvidedType> c.DeclaringType).IsValueType), m)
         let actualTypeInst = [] // GENERIC TYPE PROVIDERS: for generics, we would have something here
         let actualMethInst = [] // GENERIC TYPE PROVIDERS: for generics, we would have something here
         let ilReturnTys = Option.toList (minfo.GetCompiledReturnType(amap, m, []))  // GENERIC TYPE PROVIDERS: for generics, we would have more here
@@ -1080,7 +1080,7 @@ let MakeMethInfoCall (amap: ImportMap) m (minfo: MethInfo) minst args staticTyOp
 // This imports a provided method, and checks if it is a known compiler intrinsic like "1 + 2"
 let TryImportProvidedMethodBaseAsLibraryIntrinsic (amap: Import.ImportMap, m: range, mbase: Tainted<ProvidedMethodBase>) = 
     let methodName = mbase.PUntaint((fun x -> x.Name), m)
-    let declaringType = Import.ImportProvidedType amap m (mbase.PApply((fun x -> x.DeclaringType), m))
+    let declaringType = Import.ImportProvidedType amap m (mbase.PApply((fun x -> nonNull<ProvidedType> x.DeclaringType), m))
     match tryTcrefOfAppTy amap.g declaringType with
     | ValueSome declaringEntity ->
         if not declaringEntity.IsLocalRef && ccuEq declaringEntity.nlr.Ccu amap.g.fslibCcu then
@@ -2042,7 +2042,7 @@ module ProvidedMethodCalls =
         let thisArg, paramVars = 
             match objArgs with
             | [objArg] -> 
-                let erasedThisTy = eraseSystemType (amap, m, mi.PApply((fun mi -> mi.DeclaringType), m))
+                let erasedThisTy = eraseSystemType (amap, m, mi.PApply((fun mi -> nonNull<ProvidedType> mi.DeclaringType), m))
                 let thisVar = erasedThisTy.PApply((fun ty -> ty.AsProvidedVar("this")), m)
                 Some objArg, Array.append [| thisVar |] paramVars
             | [] -> None, paramVars
@@ -2062,7 +2062,7 @@ module ProvidedMethodCalls =
             methInfoOpt, expr, exprTy
         with
             | :? TypeProviderError as tpe ->
-                let typeName = mi.PUntaint((fun mb -> mb.DeclaringType.FullName), m)
+                let typeName = mi.PUntaint((fun mb -> (nonNull<ProvidedType> mb.DeclaringType).FullName), m)
                 let methName = mi.PUntaint((fun mb -> mb.Name), m)
                 raise( tpe.WithContext(typeName, methName) )  // loses original stack trace
 #endif

src/Compiler/Checking/MethodOverrides.fs

@@ -621,7 +621,7 @@ module DispatchSlotChecking =
                     // dispatch slots are ordered from the derived classes to base
                     // so we can check the topmost dispatch slot if it is final
                     match dispatchSlots with
-                    | meth :: _ when meth.IsFinal -> errorR(Error(FSComp.SR.tcCannotOverrideSealedMethod (sprintf "%s::%s" (meth.ApparentEnclosingType.ToString()) meth.LogicalName), m))
+                    | meth :: _ when meth.IsFinal -> errorR(Error(FSComp.SR.tcCannotOverrideSealedMethod((sprintf "%s::%s" (NicePrint.stringOfTy denv meth.ApparentEnclosingType) meth.LogicalName)), m))
                     | _ -> ()
 
     /// Get the slots of a type that can or must be implemented. This depends

src/Compiler/Checking/TypeHierarchy.fs

@@ -41,44 +41,47 @@ let GetSuperTypeOfType g amap m ty =
     let ty = stripTyEqnsAndMeasureEqns g ty
 #endif
 
-    match metadataOfTy g ty with
+    let resBeforeNull = 
+        match metadataOfTy g ty with
 #if !NO_TYPEPROVIDERS
-    | ProvidedTypeMetadata info ->
-        let st = info.ProvidedType
-        let superOpt = st.PApplyOption((fun st -> match st.BaseType with null -> None | t -> Some t), m)
-        match superOpt with
-        | None -> None
-        | Some super -> Some(ImportProvidedType amap m super)
+        | ProvidedTypeMetadata info ->
+            let st = info.ProvidedType
+            let superOpt = st.PApplyOption((fun st -> match st.BaseType with null -> None | t -> Some t), m)
+            match superOpt with
+            | None -> None
+            | Some super -> Some(ImportProvidedType amap m super)
 #endif
-    | ILTypeMetadata (TILObjectReprData(scoref, _, tdef)) ->
-        let tinst = argsOfAppTy g ty
-        match tdef.Extends with
-        | None -> None
-        | Some ilTy -> Some (RescopeAndImportILType scoref amap m tinst ilTy)
-
-    | FSharpOrArrayOrByrefOrTupleOrExnTypeMetadata ->
-        if isFSharpObjModelTy g ty || isFSharpExceptionTy g ty then
-            let tcref = tcrefOfAppTy g ty
-            Some (instType (mkInstForAppTy g ty) (superOfTycon g tcref.Deref))
-        elif isArrayTy g ty then
-            Some g.system_Array_ty
-        elif isRefTy g ty && not (isObjTy g ty) then
-            Some g.obj_ty
-        elif isStructTupleTy g ty then
-            Some g.system_Value_ty
-        elif isFSharpStructOrEnumTy g ty then
-            if isFSharpEnumTy g ty then
-                Some g.system_Enum_ty
-            else
+        | ILTypeMetadata (TILObjectReprData(scoref, _, tdef)) ->
+            let tinst = argsOfAppTy g ty
+            match tdef.Extends with
+            | None -> None
+            | Some ilTy -> Some (RescopeAndImportILType scoref amap m tinst ilTy)
+
+        | FSharpOrArrayOrByrefOrTupleOrExnTypeMetadata ->
+            if isFSharpObjModelTy g ty || isFSharpExceptionTy g ty then
+                let tcref = tcrefOfAppTy g ty
+                Some (instType (mkInstForAppTy g ty) (superOfTycon g tcref.Deref))
+            elif isArrayTy g ty then
+                Some g.system_Array_ty
+            elif isRefTy g ty && not (isObjTy g ty) then
+                Some g.obj_ty
+            elif isStructTupleTy g ty then
+                Some g.system_Value_ty
+            elif isFSharpStructOrEnumTy g ty then
+                if isFSharpEnumTy g ty then
+                    Some g.system_Enum_ty
+                else
+                    Some g.system_Value_ty
+            elif isStructAnonRecdTy g ty then
                 Some g.system_Value_ty
-        elif isStructAnonRecdTy g ty then
-            Some g.system_Value_ty
-        elif isAnonRecdTy g ty then
-            Some g.obj_ty
-        elif isRecdTy g ty || isUnionTy g ty then
-            Some g.obj_ty
-        else
-            None
+            elif isAnonRecdTy g ty then
+                Some g.obj_ty
+            elif isRecdTy g ty || isUnionTy g ty then
+                Some g.obj_ty
+            else
+                None
+
+    resBeforeNull
 
 /// Make a type for System.Collections.Generic.IList<ty>
 let mkSystemCollectionsGenericIListTy (g: TcGlobals) ty =

src/Compiler/Checking/import.fs

@@ -38,7 +38,7 @@ type AssemblyLoader =
     /// Get a flag indicating if an assembly is a provided assembly, plus the
     /// table of information recording remappings from type names in the provided assembly to type
     /// names in the statically linked, embedded assembly.
-    abstract GetProvidedAssemblyInfo : CompilationThreadToken * range * Tainted<ProvidedAssembly> -> bool * ProvidedAssemblyStaticLinkingMap option
+    abstract GetProvidedAssemblyInfo : CompilationThreadToken * range * Tainted<ProvidedAssembly MaybeNull> -> bool * ProvidedAssemblyStaticLinkingMap option
 
     /// Record a root for a [<Generate>] type to help guide static linking & type relocation
     abstract RecordGeneratedTypeRoot : ProviderGeneratedType -> unit
@@ -183,16 +183,24 @@ let rec ImportILType (env: ImportMap) m tinst ty =
         ImportTyconRefApp env tcref inst
 
     | ILType.Byref ty -> mkByrefTy env.g (ImportILType env m tinst ty)
+
     | ILType.Ptr ILType.Void  when env.g.voidptr_tcr.CanDeref -> mkVoidPtrTy env.g
+
     | ILType.Ptr ty  -> mkNativePtrTy env.g (ImportILType env m tinst ty)
+
     | ILType.FunctionPointer _ -> env.g.nativeint_ty (* failwith "cannot import this kind of type (ptr, fptr)" *)
+
     | ILType.Modified(_, _, ty) -> 
          // All custom modifiers are ignored
          ImportILType env m tinst ty
+
     | ILType.TypeVar u16 -> 
-         try List.item (int u16) tinst
-         with _ -> 
-              error(Error(FSComp.SR.impNotEnoughTypeParamsInScopeWhileImporting(), m))
+        let ty = 
+            try 
+                List.item (int u16) tinst
+            with _ -> 
+                error(Error(FSComp.SR.impNotEnoughTypeParamsInScopeWhileImporting(), m))
+        ty
 
 /// Determines if an IL type can be imported as an F# type
 let rec CanImportILType (env: ImportMap) m ty =  
@@ -354,15 +362,15 @@ let rec ImportProvidedType (env: ImportMap) (m: range) (* (tinst: TypeInst) *) (
 
 /// Import a provided method reference as an Abstract IL method reference
 let ImportProvidedMethodBaseAsILMethodRef (env: ImportMap) (m: range) (mbase: Tainted<ProvidedMethodBase>) = 
-     let tref = GetILTypeRefOfProvidedType (mbase.PApply((fun mbase -> mbase.DeclaringType), m), m)
+     let tref = GetILTypeRefOfProvidedType (mbase.PApply((fun mbase -> nonNull<ProvidedType> mbase.DeclaringType), m), m)
 
      let mbase = 
          // Find the formal member corresponding to the called member
          match mbase.OfType<ProvidedMethodInfo>() with 
          | Some minfo when 
-                    minfo.PUntaint((fun minfo -> minfo.IsGenericMethod|| minfo.DeclaringType.IsGenericType), m) -> 
+                    minfo.PUntaint((fun minfo -> minfo.IsGenericMethod|| (nonNull<ProvidedType> minfo.DeclaringType).IsGenericType), m) -> 
 
-                let declaringType = minfo.PApply((fun minfo -> minfo.DeclaringType), m)
+                let declaringType = minfo.PApply((fun minfo -> nonNull<ProvidedType> minfo.DeclaringType), m)
 
                 let declaringGenericTypeDefn =  
                     if declaringType.PUntaint((fun t -> t.IsGenericType), m) then 
@@ -381,8 +389,8 @@ let ImportProvidedMethodBaseAsILMethodRef (env: ImportMap) (m: range) (mbase: Ta
                     error(Error(FSComp.SR.etIncorrectProvidedMethod(DisplayNameOfTypeProvider(minfo.TypeProvider, m), methodName, metadataToken, typeName), m))
          | _ -> 
          match mbase.OfType<ProvidedConstructorInfo>() with 
-         | Some cinfo when cinfo.PUntaint((fun x -> x.DeclaringType.IsGenericType), m) -> 
-                let declaringType = cinfo.PApply((fun x -> x.DeclaringType), m)
+         | Some cinfo when cinfo.PUntaint((fun x -> (nonNull<ProvidedType> x.DeclaringType).IsGenericType), m) -> 
+                let declaringType = cinfo.PApply((fun x -> nonNull<ProvidedType> x.DeclaringType), m)
                 let declaringGenericTypeDefn =  declaringType.PApply((fun x -> x.GetGenericTypeDefinition()), m)
 
                 // We have to find the uninstantiated formal signature corresponding to this instantiated constructor.