Remove ExactSpelling from GeneratedDllImport (dotnet#65343)

* Update conversion code fix to offer multiple fixes for appending each previously probed entry-point suffix when ExactSpelling is false.

* Remove ExactSpelling property and move properties that were relying on ExactSpelling = false to use explicit entrypoint names.

* Emit ExactSpelling = true for all of our emitted target DllImports.

* Fix a few entry points

* Add a comment around CharSet.Auto

* Update compatibility doc.

* Update docs/design/libraries/DllImportGenerator/Compatibility.md

Co-authored-by: Elinor Fung <elfung@microsoft.com>

Co-authored-by: Elinor Fung <elfung@microsoft.com>

Author: jkoritzinsky

docs/design/libraries/DllImportGenerator/Compatibility.md

@@ -20,6 +20,8 @@ The built-in system treats `CharSet.None` as `CharSet.Ansi`. The P/Invoke source
 
 [`CallingConvention`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.dllimportattribute.callingconvention) will not be supported for `GeneratedDllImportAttribute`. Users will be required to use the new `UnmanagedCallConvAttribute` attribute instead. This attribute provides support for extensible calling conventions and provides parity with the `UnmanagedCallersOnlyAttribute` attribute and C# function pointer syntax. We will enable our conversion code-fix to automatically convert explicit and known calling convention usage to use the `UnmanagedCallConvAttribute`.
 
+[`ExactSpelling`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.dllimportattribute.exactspelling) will not be supported for `GeneratedDllImportAttribute`. If `ExactSpelling` is used on an existing `DllImport`, the offered code-fix will provide users with additional options for using `A` or `W` suffixed variants depending on the provided `CharSet` so they can explicitly choose which spelling is correct for their scenario.
+
 ### Required references
 
 The following framework references are required:

src/coreclr/nativeaot/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs

@@ -26,12 +26,12 @@ public static partial class RuntimeImports
     {
         private const string RuntimeLibrary = "*";
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         [SuppressGCTransition]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static partial ulong RhpGetTickCount64();
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static partial IntPtr RhpGetCurrentThread();
 
@@ -69,7 +69,7 @@ internal static void RhReRegisterForFinalize(object obj)
         private static extern bool _RhReRegisterForFinalize(object obj);
 
         // Wait for all pending finalizers. This must be a p/invoke to avoid starving the GC.
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         private static partial void RhWaitForPendingFinalizers(int allowReentrantWait);
 
         // Temporary workaround to unblock shareable assembly bring-up - without shared interop,
@@ -82,7 +82,7 @@ internal static void RhWaitForPendingFinalizers(bool allowReentrantWait)
             RhWaitForPendingFinalizers(allowReentrantWait ? 1 : 0);
         }
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         internal static partial void RhInitializeFinalizerThread();
 
         // Get maximum GC generation number.
@@ -187,18 +187,18 @@ internal static void RhWaitForPendingFinalizers(bool allowReentrantWait)
         [RuntimeImport(RuntimeLibrary, "RhGetTotalAllocatedBytes")]
         internal static extern long RhGetTotalAllocatedBytes();
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static partial long RhGetTotalAllocatedBytesPrecise();
 
         [MethodImpl(MethodImplOptions.InternalCall)]
         [RuntimeImport(RuntimeLibrary, "RhGetMemoryInfo")]
         internal static extern void RhGetMemoryInfo(ref byte info, GCKind kind);
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         internal static unsafe partial void RhAllocateNewArray(IntPtr pArrayEEType, uint numElements, uint flags, void* pResult);
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         internal static unsafe partial void RhAllocateNewObject(IntPtr pEEType, uint flags, void* pResult);
 
         [MethodImpl(MethodImplOptions.InternalCall)]
@@ -368,25 +368,25 @@ internal static unsafe void RhUnbox(object? obj, ref byte data, EETypePtr pUnbox
         internal static extern object RhMemberwiseClone(object obj);
 
         // Busy spin for the given number of iterations.
-        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhSpinWait", ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhSpinWait")]
         [SuppressGCTransition]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static partial void RhSpinWait(int iterations);
 
         // Yield the cpu to another thread ready to process, if one is available.
-        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhYield", ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhYield")]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         private static partial int _RhYield();
         internal static bool RhYield() { return (_RhYield() != 0); }
 
-        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhFlushProcessWriteBuffers", ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhFlushProcessWriteBuffers")]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static partial void RhFlushProcessWriteBuffers();
 
 #if !TARGET_UNIX
         // Wait for any object to be signalled, in a way that's compatible with the CLR's behavior in an STA.
         // ExactSpelling = 'true' to force MCG to resolve it to default
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         private static unsafe partial int RhCompatibleReentrantWaitAny(int alertable, int timeout, int count, IntPtr* handles);
 
         // Temporary workaround to unblock shareable assembly bring-up - without shared interop,
@@ -617,7 +617,7 @@ internal static IntPtr RhGetModuleSection(TypeManagerHandle module, ReadyToRunSe
         internal static extern void RhCallDescrWorker(IntPtr callDescr);
 
         // For Managed to Native calls
-        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhCallDescrWorker", ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary, EntryPoint = "RhCallDescrWorker")]
         internal static partial void RhCallDescrWorkerNative(IntPtr callDescr);
 
         // Moves memory from smem to dmem. Size must be a positive value.
@@ -935,14 +935,14 @@ internal struct ConservativelyReportedRegionDesc
         [RuntimeImport(RuntimeLibrary, "modff")]
         internal static extern unsafe float modff(float x, float* intptr);
 
-        [GeneratedDllImport(RuntimeImports.RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeImports.RuntimeLibrary)]
         internal static unsafe partial void* memmove(byte* dmem, byte* smem, nuint size);
 
-        [GeneratedDllImport(RuntimeImports.RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeImports.RuntimeLibrary)]
         internal static unsafe partial void* memset(byte* mem, int value, nuint size);
 
 #if TARGET_X86 || TARGET_AMD64
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         [UnmanagedCallConv(CallConvs = new Type[] { typeof(CallConvCdecl) })]
         internal static unsafe partial void RhCpuIdEx(int* cpuInfo, int functionId, int subFunctionId);
 #endif

src/coreclr/nativeaot/Test.CoreLib/src/System/Runtime/RuntimeImports.cs

@@ -85,7 +85,7 @@ internal static unsafe object RhNewObject(EETypePtr pEEType)
         internal static unsafe Array RhNewArray(EETypePtr pEEType, int length)
             => RhNewArray(pEEType.ToPointer(), length);
 
-        [GeneratedDllImport(RuntimeLibrary, ExactSpelling = true)]
+        [GeneratedDllImport(RuntimeLibrary)]
         internal static unsafe partial void RhAllocateNewObject(IntPtr pEEType, uint flags, void* pResult);
 
         [MethodImpl(MethodImplOptions.InternalCall)]

src/libraries/Common/src/Interop/Unix/System.Native/Interop.GetTimestamp.cs

@@ -7,7 +7,7 @@ internal static partial class Interop
 {
     internal static partial class Sys
     {
-        [GeneratedDllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetTimestamp", ExactSpelling = true)]
+        [GeneratedDllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetTimestamp")]
         [SuppressGCTransition]
         internal static partial ulong GetTimestamp();
     }

src/libraries/Common/src/Interop/Windows/Activeds/Interop.ADsOpenObject.cs

@@ -8,7 +8,7 @@ internal static partial class Interop
 {
     internal static partial class Activeds
     {
-        [GeneratedDllImport(Interop.Libraries.Activeds, CharSet = CharSet.Unicode, ExactSpelling = true)]
+        [GeneratedDllImport(Interop.Libraries.Activeds, CharSet = CharSet.Unicode)]
         internal static partial int ADsOpenObject(string path, string? userName, string? password, int flags, ref Guid iid, out IntPtr ppObject);
     }
 }

src/libraries/Common/src/Interop/Windows/Advapi32/Interop.ChangeServiceConfig2.cs

@@ -9,7 +9,7 @@ internal static partial class Interop
 {
     internal static partial class Advapi32
     {
-        [GeneratedDllImport(Libraries.Advapi32, EntryPoint = "ChangeServiceConfig2W", ExactSpelling = true, SetLastError = true)]
+        [GeneratedDllImport(Libraries.Advapi32, EntryPoint = "ChangeServiceConfig2W", SetLastError = true)]
         public static partial bool ChangeServiceConfig2(SafeServiceHandle serviceHandle, uint infoLevel, ref SERVICE_DESCRIPTION serviceDesc);
 
 #pragma warning disable DLLIMPORTGENANALYZER015 // Use 'GeneratedDllImportAttribute' instead of 'DllImportAttribute' to generate P/Invoke marshalling code at compile time

src/libraries/Common/src/Interop/Windows/Advapi32/Interop.ClearEventLog.cs

@@ -8,7 +8,7 @@ internal static partial class Interop
 {
     internal static partial class Advapi32
     {
-        [GeneratedDllImport(Libraries.Advapi32, CharSet = CharSet.Unicode, SetLastError = true)]
+        [GeneratedDllImport(Libraries.Advapi32, EntryPoint = "ClearEventLogW", CharSet = CharSet.Unicode, SetLastError = true)]
         public static partial bool ClearEventLog(SafeEventLogReadHandle hEventLog, string lpBackupFileName);
     }
 }

src/libraries/Common/src/Interop/Windows/Advapi32/Interop.ConvertSdToStringSd.cs

@@ -9,7 +9,7 @@ internal static partial class Interop
     internal static partial class Advapi32
     {
         [GeneratedDllImport(Interop.Libraries.Advapi32, EntryPoint = "ConvertSecurityDescriptorToStringSecurityDescriptorW",
-            CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
+            CharSet = CharSet.Unicode, SetLastError = true)]
         internal static partial bool ConvertSdToStringSd(
             byte[] securityDescriptor,
             /* DWORD */ uint requestedRevision,

src/libraries/Common/src/Interop/Windows/Advapi32/Interop.ConvertSidToStringSid.cs

@@ -8,7 +8,7 @@ internal static partial class Interop
 {
     internal static partial class Advapi32
     {
-        [GeneratedDllImport(Libraries.Advapi32, EntryPoint = "ConvertSidToStringSidW", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
+        [GeneratedDllImport(Libraries.Advapi32, EntryPoint = "ConvertSidToStringSidW", CharSet = CharSet.Unicode, SetLastError = true)]
         internal static partial BOOL ConvertSidToStringSid(IntPtr sid, out string stringSid);
     }
 }

src/libraries/Common/src/Interop/Windows/Advapi32/Interop.ConvertStringSdToSd.cs

@@ -9,7 +9,7 @@ internal static partial class Interop
     internal static partial class Advapi32
     {
         [GeneratedDllImport(Interop.Libraries.Advapi32, EntryPoint = "ConvertStringSecurityDescriptorToSecurityDescriptorW",
-            CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = true)]
+            CharSet = CharSet.Unicode, SetLastError = true)]
         internal static partial bool ConvertStringSdToSd(
             string stringSd,
             /* DWORD */ uint stringSdRevision,