Fix part of 3465 - allow nativeptr address in 'let x = &&expr' (#3525)

* Fix part of 3465 - allow nativeptr address of in 'let'

* fix tests

* fix test

* fix test

src/fsharp/PostInferenceChecks.fs

@@ -624,7 +624,7 @@ and CheckExpr (cenv:cenv) (env:env) expr (context:ByrefContext) =
         CheckExprsPermitByrefs cenv env rest
 
     | Expr.Op (c,tyargs,args,m) ->
-          CheckExprOp cenv env (c,tyargs,args,m) context
+          CheckExprOp cenv env (c,tyargs,args,m) context expr
 
     // Allow 'typeof<System.Void>' calls as a special case, the only accepted use of System.Void! 
     | TypeOfExpr cenv.g ty when isVoidTy cenv.g ty ->
@@ -734,7 +734,7 @@ and CheckInterfaceImpls cenv env baseValOpt l =
 and CheckInterfaceImpl cenv env baseValOpt (_ty,overrides) = 
     CheckMethods cenv env baseValOpt overrides 
 
-and CheckExprOp cenv env (op,tyargs,args,m) context =
+and CheckExprOp cenv env (op,tyargs,args,m) context expr =
     let limitedCheck() = 
         if env.limited then errorR(Error(FSComp.SR.chkObjCtorsCantUseExceptionHandling(), m))
     List.iter (CheckTypePermitByrefs cenv env m) tyargs
@@ -828,13 +828,13 @@ and CheckExprOp cenv env (op,tyargs,args,m) context =
         CheckTypeInstNoByrefs cenv env m tyargs        
 
     | TOp.ValFieldGetAddr rfref,tyargs,[] ->
-        if noByrefs context && cenv.reportErrors then
+        if noByrefs context && cenv.reportErrors && isByrefLikeTy cenv.g (tyOfExpr cenv.g expr) then
             errorR(Error(FSComp.SR.chkNoAddressStaticFieldAtThisPoint(rfref.FieldName), m)) 
         CheckTypeInstNoByrefs cenv env m tyargs
         // NOTE: there are no arg exprs to check in this case 
 
     | TOp.ValFieldGetAddr rfref,tyargs,[rx] ->
-        if noByrefs context && cenv.reportErrors then
+        if noByrefs context && cenv.reportErrors  && isByrefLikeTy cenv.g (tyOfExpr cenv.g expr) then
             errorR(Error(FSComp.SR.chkNoAddressFieldAtThisPoint(rfref.FieldName), m))
         // This construct is used for &(rx.rfield) and &(rx->rfield). Relax to permit byref types for rx. [See Bug 1263]. 
         CheckTypeInstNoByrefs cenv env m tyargs
@@ -849,7 +849,7 @@ and CheckExprOp cenv env (op,tyargs,args,m) context =
         CheckExprPermitByref cenv env arg1  // allow byref - it may be address-of-struct
 
     | TOp.UnionCaseFieldGetAddr (uref, _idx),tyargs,[rx] ->
-        if noByrefs context && cenv.reportErrors then
+        if noByrefs context && cenv.reportErrors  && isByrefLikeTy cenv.g (tyOfExpr cenv.g expr) then
           errorR(Error(FSComp.SR.chkNoAddressFieldAtThisPoint(uref.CaseName), m))
         CheckTypeInstNoByrefs cenv env m tyargs
         // allow rx to be byref here, for struct unions
@@ -870,12 +870,12 @@ and CheckExprOp cenv env (op,tyargs,args,m) context =
             // permit byref for lhs lvalue of readonly value 
             CheckExprPermitByref cenv env lhs
         | [ I_ldflda (fspec) | I_ldsflda (fspec) ],[lhs] ->
-            if noByrefs context && cenv.reportErrors then
+            if noByrefs context && cenv.reportErrors  && isByrefLikeTy cenv.g (tyOfExpr cenv.g expr) then
                 errorR(Error(FSComp.SR.chkNoAddressFieldAtThisPoint(fspec.Name), m))
             // permit byref for lhs lvalue
             CheckExprPermitByref cenv env lhs
         | [ I_ldelema (_,isNativePtr,_,_) ],lhsArray::indices ->
-            if not(isNativePtr) && noByrefs context && cenv.reportErrors then
+            if noByrefs context && cenv.reportErrors && not isNativePtr && isByrefLikeTy cenv.g (tyOfExpr cenv.g expr) then
                 errorR(Error(FSComp.SR.chkNoAddressOfArrayElementAtThisPoint(), m))
             // permit byref for lhs lvalue 
             CheckExprPermitByref cenv env lhsArray
@@ -982,7 +982,7 @@ and CheckLambdas isTop (memInfo: ValMemberInfo option) cenv env inlined topValIn
     | _ -> 
         // Permit byrefs for let x = ...
         CheckTypePermitByrefs cenv env m ety
-        if not inlined && isByrefLikeTy cenv.g ety then
+        if not inlined && (isByrefLikeTy cenv.g ety || isNativePtrTy cenv.g ety) then
             // allow byref to occur as RHS of byref binding. 
             CheckExprPermitByref cenv env e
         else 

tests/fsharp/tests.fs

@@ -1681,6 +1681,12 @@ module TypecheckTests =
 
         peverify cfg "pos27.exe"
 
+    [<Test>]
+    let ``sigs pos28`` () = 
+        let cfg = testConfig "typecheck/sigs"
+        fsc cfg "%s --target:exe -o:pos28.exe" cfg.fsc_flags ["pos28.fs"]
+        peverify cfg "pos28.exe"
+
     [<Test>]
     let ``sigs pos26`` () = 
         let cfg = testConfig "typecheck/sigs"

tests/fsharp/typecheck/sigs/pos28.fs

+module Pos28
+
+open FSharp.NativeInterop
+
+module Test1 = 
+    [<Struct>]
+    type Point =
+        val mutable X: int
+        val mutable Y: int
+        new(x,y) = { X=x; Y=y; }    
+
+    let fixPoint1() =
+        let mutable point = Point(1,2)
+        let p1 = &&point.X
+        NativePtr.read<int> p1
+
+module Test2 = 
+    [<Struct>]
+    type Point = { mutable x : int; mutable y : int }
+
+    let fixPoint1() =
+        let mutable point = Unchecked.defaultof<Point>
+        let p1 = &&point.x
+        NativePtr.read<int> p1
+

tests/fsharpqa/Source/Conformance/Expressions/DataExpressions/AddressOf/E_byrefvaluesnotpermitted002.fs

-// #Regression #Conformance #DataExpressions 
-// AddressOf Operator (warnings)
-// Verify we can the compiler always issue warnings about using & and && operators
-//<Expects status="warning" span="(9,11-9,14)" id="FS0051">The use of native pointers may result in unverifiable \.NET IL code$</Expects>
-//<Expects status="error" span="(9,13-9,14)" id="FS0421">The address of the variable 'x' cannot be used at this point$</Expects>
-
-module M =
-  let mutable x = 10
-  let w = &&x
-

tests/fsharpqa/Source/Conformance/Expressions/DataExpressions/AddressOf/env.lst

@@ -3,4 +3,3 @@ NoMT	SOURCE=addressof001.fsx PRECMD="\$CSC_PIPE /t:library addressof001dll.cs"
 NoMT	SOURCE=addressof002.fsx PRECMD="\$CSC_PIPE /t:library addressof002dll.cs"							# addressof002.fsx
 NOMONO	SOURCE=addressof003.fs SCFLAGS="--test:ErrorRanges" PRECMD="copy /y addressof003dll_%OSARCH%.dll addressof003dll.dll" PEVER=/MD	# addressof003.fs
 	SOURCE=E_byrefvaluesnotpermitted001.fs SCFLAGS="--test:ErrorRanges"								# E_byrefvaluesnotpermitted001.fs
-	SOURCE=E_byrefvaluesnotpermitted002.fs SCFLAGS="--test:ErrorRanges"								# E_byrefvaluesnotpermitted002.fs