Change Auto charset to mean UTF-8 off-Windows (#23664)

Match Mono's behavior by changing the Auto character set to mean UTF-8 on non-Windows platforms (new behavior) and UCS-2/UTF-16 on Windows (current behavior).

Fixes #23464
Fixes dotnet/corefx#32442

Impact of breaking change: It is highly unlikely that anyone is actively using current behavior since it is inconsistent with Mono and doesn't match any native system APIs on non-Windows platforms (they're all UTF-8 based).

We will need to update our documentation to reflect this updated behavior.

diff --git a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Unix.cs b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Unix.cs
index 1f049bd..08892b1 100644 (file)
--- a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Unix.cs
+++ b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Unix.cs
@@ -9,6 +9,26 @@ namespace System.Runtime.InteropServices
 {
     public static partial class Marshal
     {
+        public static string PtrToStringAuto(IntPtr ptr, int len)
+        {
+            return PtrToStringUTF8(ptr, len);
+        }
+
+        public static string PtrToStringAuto(IntPtr ptr)
+        {
+            return PtrToStringUTF8(ptr);
+        }
+
+        public static IntPtr StringToHGlobalAuto(string s)
+        {
+            return StringToHGlobalUTF8(s);
+        }
+
+        public static IntPtr StringToCoTaskMemAuto(string s)
+        {
+            return StringToCoTaskMemUTF8(s);
+        }
+
         private static int GetSystemMaxDBCSCharSize() => 3;
 
         private static bool IsWin32Atom(IntPtr ptr) => false;
@@ -29,4 +49,4 @@ namespace System.Runtime.InteropServices
             return convertedBytes;
         }
     }
-}
\ No newline at end of file
+}

diff --git a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Windows.cs b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Windows.cs
index 5a44e49..c9e1baf 100644 (file)
--- a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Windows.cs
+++ b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.Windows.cs
@@ -8,6 +8,26 @@ namespace System.Runtime.InteropServices
 {
     public static partial class Marshal
     {
+        public static string PtrToStringAuto(IntPtr ptr, int len)
+        {
+            return PtrToStringUni(ptr, len);
+        }
+
+        public static string PtrToStringAuto(IntPtr ptr)
+        {
+            return PtrToStringUni(ptr);
+        }
+
+        public static IntPtr StringToHGlobalAuto(string s)
+        {
+            return StringToHGlobalUni(s);
+        }
+
+        public static IntPtr StringToCoTaskMemAuto(string s)
+        {
+            return StringToCoTaskMemUni(s);
+        }
+
         private static unsafe int GetSystemMaxDBCSCharSize()
         {
             Interop.Kernel32.CPINFO cpInfo = default;
@@ -63,4 +83,4 @@ namespace System.Runtime.InteropServices
             return nb;
         }
     }
-}
\ No newline at end of file
+}

diff --git a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.cs b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.cs
index a1c2f17..99ab101 100644 (file)
--- a/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.cs
+++ b/src/System.Private.CoreLib/shared/System/Runtime/InteropServices/Marshal.cs
@@ -87,18 +87,6 @@ namespace System.Runtime.InteropServices
             return new string((char*)ptr, 0, len);
         }
 
-        public static string PtrToStringAuto(IntPtr ptr, int len)
-        {
-            // Ansi platforms are no longer supported
-            return PtrToStringUni(ptr, len);
-        }
-
-        public static string PtrToStringAuto(IntPtr ptr)
-        {
-            // Ansi platforms are no longer supported
-            return PtrToStringUni(ptr);
-        }
-
         public static unsafe string PtrToStringUTF8(IntPtr ptr)
         {
             if (ptr == IntPtr.Zero)
@@ -726,10 +714,28 @@ namespace System.Runtime.InteropServices
             return hglobal;
         }
 
-        public static IntPtr StringToHGlobalAuto(string s)
+        private static unsafe IntPtr StringToHGlobalUTF8(string s)
         {
-            // Ansi platforms are no longer supported
-            return StringToHGlobalUni(s);
+            if (s == null)
+            {
+                return IntPtr.Zero;
+            }
+
+            int nb = Encoding.UTF8.GetMaxByteCount(s.Length);
+
+            IntPtr pMem = AllocHGlobal(nb + 1);
+
+            int nbWritten;
+            byte* pbMem = (byte*)pMem;
+
+            fixed (char* firstChar = s)
+            {
+                nbWritten = Encoding.UTF8.GetBytes(firstChar, s.Length, pbMem, nb);
+            }
+
+            pbMem[nbWritten] = 0;
+
+            return pMem;
         }
 
         public static unsafe IntPtr StringToCoTaskMemUni(string s)
@@ -780,12 +786,6 @@ namespace System.Runtime.InteropServices
             return pMem;
         }
 
-        public static IntPtr StringToCoTaskMemAuto(string s)
-        {
-            // Ansi platforms are no longer supported
-            return StringToCoTaskMemUni(s);
-        }
-
         public static unsafe IntPtr StringToCoTaskMemAnsi(string s)
         {
             if (s == null)

diff --git a/src/vm/dllimport.cpp b/src/vm/dllimport.cpp
index 5fa9ac4..252ec56 100644 (file)
--- a/src/vm/dllimport.cpp
+++ b/src/vm/dllimport.cpp
@@ -2965,8 +2965,14 @@ PInvokeStaticSigInfo::PInvokeStaticSigInfo(MethodDesc* pMD, ThrowOnError throwOn
         case nltAnsi:
             nlt = nltAnsi; break;
         case nltUnicode:
-        case nltAuto:   // Since Win9x isn't supported anymore, nltAuto always represents unicode strings.
             nlt = nltUnicode; break;
+        case nltAuto:
+#ifdef PLATFORM_WINDOWS
+            nlt = nltUnicode;
+#else
+            nlt = nltAnsi; // We don't have a utf8 charset in metadata yet, but ANSI == UTF-8 off-Windows
+#endif
+        break;
         default:
             hr = E_FAIL; goto ErrExit;
         }
@@ -3088,7 +3094,6 @@ void PInvokeStaticSigInfo::DllImportInit(MethodDesc* pMD, LPCUTF8 *ppLibName, LP
     if (mappingFlags & pmNoMangle)
         SetLinkFlags ((CorNativeLinkFlags)(GetLinkFlags() | nlfNoMangle));
 
-    // XXX Tue 07/19/2005
     // Keep in sync with the handling of CorNativeLinkType in
     // PInvokeStaticSigInfo::PInvokeStaticSigInfo.
     
@@ -3098,11 +3103,18 @@ void PInvokeStaticSigInfo::DllImportInit(MethodDesc* pMD, LPCUTF8 *ppLibName, LP
     {
         SetCharSet (nltAnsi);
     }
-    else if (charSetMask == pmCharSetUnicode || charSetMask == pmCharSetAuto)
+    else if (charSetMask == pmCharSetUnicode)
     {
-        // Since Win9x isn't supported anymore, pmCharSetAuto always represents unicode strings.
         SetCharSet (nltUnicode);
     }
+    else if (charSetMask == pmCharSetAuto)
+    {
+#ifdef PLATFORM_WINDOWS
+        SetCharSet(nltUnicode);
+#else
+        SetCharSet(nltAnsi); // We don't have a utf8 charset in metadata yet, but ANSI == UTF-8 off-Windows
+#endif
+    }
     else
     {
         SetError(IDS_EE_NDIRECT_BADNATL);

diff --git a/src/vm/methodtablebuilder.cpp b/src/vm/methodtablebuilder.cpp
index d4ce5b0..b946026 100644 (file)
--- a/src/vm/methodtablebuilder.cpp
+++ b/src/vm/methodtablebuilder.cpp
@@ -11913,10 +11913,18 @@ BOOL HasLayoutMetadata(Assembly* pAssembly, IMDInternalImport* pInternalImport,
     {
         *pNLTType = nltAnsi;
     }
-    else if (IsTdUnicodeClass(clFlags) || IsTdAutoClass(clFlags))
+    else if (IsTdUnicodeClass(clFlags))
     {
         *pNLTType = nltUnicode;
     }
+    else if (IsTdAutoClass(clFlags))
+    {
+#ifdef PLATFORM_WINDOWS
+        *pNLTType = nltUnicode;
+#else
+        *pNLTType = nltAnsi; // We don't have a utf8 charset in metadata yet, but ANSI == UTF-8 off-Windows
+#endif
+    }
     else
     {
         pAssembly->ThrowTypeLoadException(pInternalImport, cl, IDS_CLASSLOAD_BADFORMAT);

diff --git a/tests/CoreFX/CoreFX.issues.json b/tests/CoreFX/CoreFX.issues.json
index 28eb929..faa6e4b 100644 (file)
--- a/tests/CoreFX/CoreFX.issues.json
+++ b/tests/CoreFX/CoreFX.issues.json
@@ -1057,6 +1057,14 @@
                 {
                     "name": "System.Runtime.InteropServices.Tests.ArrayWithOffsetTests.Ctor_Array_Offset",
                     "reason": "outdated"
+                },
+                {
+                    "name": "System.Runtime.InteropServices.Tests.StringToCoTaskMemAutoTests.StringToCoTaskMemAuto_NonNullString_Roundtrips",
+                    "reason": "outdated"
+                },
+                {
+                    "name": "System.Runtime.InteropServices.Tests.StringToHGlobalAutoTests.StringToHGlobalAuto_NonNullString_Roundtrips",
+                    "reason": "https://github.com/dotnet/coreclr/pull/23664"
                 }
             ]
         }

diff --git a/tests/src/Interop/PInvoke/ExactSpelling/ExactSpellingTest.cs b/tests/src/Interop/PInvoke/ExactSpelling/ExactSpellingTest.cs
index 7616e6d..f2e1a01 100644 (file)
--- a/tests/src/Interop/PInvoke/ExactSpelling/ExactSpellingTest.cs
+++ b/tests/src/Interop/PInvoke/ExactSpelling/ExactSpellingTest.cs
@@ -37,6 +37,12 @@ class ExactSpellingTest
         public static extern int MarshalPointer_Int_InOut2([In, Out] ref int intValue);
     }
 
+    class Auto
+    {
+        [DllImport("ExactSpellingNative", CharSet = CharSet.Auto, ExactSpelling = false)]
+        public static extern int Marshal_Int_InOut2([In, Out] int intValue);
+    }
+
     public static int Main(string[] args)
     {
         int failures = 0;
@@ -87,6 +93,15 @@ class ExactSpellingTest
         int int8 = intManaged;
         int intRet8 = Ansi.MarshalPointer_Int_InOut2(ref int8);
         failures += Verify(intReturnAnsi, intNative, intRet8, int8);
+
+        Console.WriteLine("Method Auto.Marshal_Int_InOut: ExactSpelling = false. Verify CharSet.Auto behavior per-platform.");
+        int int9 = intManaged;
+        int intRet9 = Auto.Marshal_Int_InOut2(int9);
+#if PLATFORM_WINDOWS
+        failures += Verify(intReturnUnicode, intManaged, intRet9, int9);
+#else
+        failures += Verify(intReturnAnsi, intManaged, intRet9, int9);
+#endif
         
         return 100 + failures;
     }

diff --git a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsLayoutSeq.cs b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsLayoutSeq.cs
index 22bb03c..6eb77a4 100644 (file)
--- a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsLayoutSeq.cs
+++ b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsLayoutSeq.cs
@@ -23,6 +23,7 @@ public class Managed
         S9Id,
         IncludeOuterIntegerStructSequentialId,
         S11Id,
+        AutoStringId,
         IntWithInnerSequentialId,
         SequentialWrapperId,
         SequentialDoubleWrapperId,
@@ -317,6 +318,9 @@ public class Managed
     static extern bool MarshalStructAsParam_AsSeqByValSequentialAggregateSequentialWrapper(AggregateSequentialWrapper wrapper);
 
     [DllImport("MarshalStructAsParam")]
+    static extern int GetStringLength(AutoString str);
+
+    [DllImport("MarshalStructAsParam")]
     static extern HFA GetHFA(float f1, float f2, float f3, float f4);
 
     [DllImport("MarshalStructAsParam")]
@@ -539,7 +543,20 @@ public class Managed
                         failures++;
                     }
                     break;
-
+                case StructID.AutoStringId:
+                    Console.WriteLine("\tCalling GetStringLength...");
+                    {
+                        AutoString autoStr = new AutoString
+                        {
+                            str = "Auto CharSet test string"
+                        };
+                        int actual = GetStringLength(autoStr);
+                        if (actual != autoStr.str.Length)
+                        {
+                            Console.WriteLine($"\tFAILED! Managed to Native failed in GetStringLength. Expected {autoStr.str.Length}, got {actual}");
+                        }
+                    }
+                    break;
                 case StructID.IntWithInnerSequentialId:
                     IntWithInnerSequential intWithInnerSeq = new IntWithInnerSequential
                     {
@@ -2217,6 +2234,7 @@ public class Managed
         MarshalStructAsParam_AsSeqByVal(StructID.S9Id);
         MarshalStructAsParam_AsSeqByVal(StructID.IncludeOuterIntegerStructSequentialId);
         MarshalStructAsParam_AsSeqByVal(StructID.S11Id);
+        MarshalStructAsParam_AsSeqByVal(StructID.AutoStringId);
         MarshalStructAsParam_AsSeqByVal(StructID.IntWithInnerSequentialId);
         MarshalStructAsParam_AsSeqByVal(StructID.SequentialWrapperId);
         MarshalStructAsParam_AsSeqByVal(StructID.SequentialDoubleWrapperId);

diff --git a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.cpp b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.cpp
index be3f046..9de3f78 100644 (file)
--- a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.cpp
+++ b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.cpp
@@ -1178,6 +1178,16 @@ extern "C" DLL_EXPORT BOOL STDMETHODCALLTYPE MarshalStructAsParam_AsExpByRefOutL
        return TRUE;
 }
 
+extern "C" DLL_EXPORT int GetStringLength(AutoString str)
+{
+#ifdef _WIN32
+    return (int)wcslen(str.str);
+#else
+    return (int)strlen(str.str);
+#endif
+}
+
+
 extern "C" DLL_EXPORT HFA STDMETHODCALLTYPE GetHFA(float f1, float f2, float f3, float f4)
 {
     return {f1, f2, f3, f4};

diff --git a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.h b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.h
index 494a8ea..dcedc46 100644 (file)
--- a/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.h
+++ b/tests/src/Interop/StructMarshalling/PInvoke/MarshalStructAsParamDLL.h
@@ -819,6 +819,15 @@ bool IsCorrectLongStructPack16Explicit(LongStructPack16Explicit* p)
        return true;
 }
 
+struct AutoString
+{
+#ifdef _WIN32
+    LPCWSTR str;
+#else
+    LPCSTR str;
+#endif
+};
+
 struct HFA
 {
     float f1;

diff --git a/tests/src/Interop/StructMarshalling/PInvoke/Struct.cs b/tests/src/Interop/StructMarshalling/PInvoke/Struct.cs
index af9d762..7ade4c3 100644 (file)
--- a/tests/src/Interop/StructMarshalling/PInvoke/Struct.cs
+++ b/tests/src/Interop/StructMarshalling/PInvoke/Struct.cs
@@ -298,6 +298,11 @@ public struct LongStructPack16Explicit
     public long l2;
 }
 
+[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
+public struct AutoString
+{
+    public string str;
+}
 
 [StructLayout(LayoutKind.Sequential)]
 public struct HFA