Disable default marshalling for bool (dotnet#65749)

Author: jkoritzinsky

docs/design/libraries/DllImportGenerator/Compatibility.md

@@ -58,6 +58,12 @@ When marshalling as [ANSI](https://docs.microsoft.com/windows/win32/intl/code-pa
 
 The p/invoke source generator does not provide an equivalent to using `CharSet.Auto` in the built-in system. If platform-dependent behaviour is desired, it is left to the user to define different p/invokes with different marshalling configurations.
 
+### `bool` marshalling
+
+We have decided to use `System.Runtime.CompilerServices.DisableRuntimeMarshalling` to enable our custom value type marshalling support. As a result, when a value type that has a `bool` field is passed to native code through source-generated marshalling, the `bool` field is treated as a 1-byte value and is not normalized. Since this default is a little odd and unlikely to be the majority use case, we're going to generally take a stance that all `bool` marshalling must be explicitly specified via `MarshalAs` or other mechanisms.
+
+To aid in conversion from `DllImport` to source-generated marshalling, the code-fix will automatically apply a `[MarshalAs(UnmangedType.Bool)]` attribute to `bool` parameters and return values to ensure the marshalling rules are not changed by the code fix.
+
 ### Custom marshaller support
 
 Using a custom marshaller (i.e. [`ICustomMarshaler`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.icustommarshaler)) with the `UnmanagedType.CustomMarshaler` value on `MarshalAsAttribute` is not supported. This also implies `MarshalAsAttribute` fields: [`MarshalTypeRef`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.marshalasattribute.marshaltyperef), [`MarshalType`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.marshalasattribute.marshaltype), and [`MarshalCookie`](https://docs.microsoft.com/dotnet/api/system.runtime.interopservices.marshalasattribute.marshalcookie) are unsupported.

src/coreclr/System.Private.CoreLib/src/System/CLRConfig.cs

@@ -16,6 +16,7 @@ internal static bool GetBoolValue(string switchName, out bool exist)
         }
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "ClrConfig_GetConfigBoolValue", StringMarshalling = StringMarshalling.Utf16)]
-        private static partial bool GetConfigBoolValue(string configSwitchName, out bool exist);
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static partial bool GetConfigBoolValue(string configSwitchName, [MarshalAs(UnmanagedType.Bool)] out bool exist);
     }
 }

src/coreclr/System.Private.CoreLib/src/System/Diagnostics/Debugger.cs

@@ -52,6 +52,7 @@ public static void NotifyOfCrossThreadDependency()
         }
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "DebugDebugger_Launch")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         private static partial bool LaunchInternal();
 
         // Returns whether or not a debugger is attached to the process.

src/coreclr/System.Private.CoreLib/src/System/Diagnostics/Eventing/EventPipe.CoreCLR.cs

@@ -50,9 +50,11 @@ private static unsafe partial ulong Enable(
         // These PInvokes are used as part of the EventPipeEventDispatcher.
         //
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "EventPipeInternal_GetSessionInfo")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         internal static unsafe partial bool GetSessionInfo(ulong sessionID, EventPipeSessionInfo* pSessionInfo);
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "EventPipeInternal_GetNextEvent")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         internal static unsafe partial bool GetNextEvent(ulong sessionID, EventPipeEventInstanceData* pInstance);
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "EventPipeInternal_GetWaitHandle")]

src/coreclr/System.Private.CoreLib/src/System/Diagnostics/Eventing/NativeRuntimeEventSource.PortableThreadPool.NativeSinks.CoreCLR.cs

@@ -52,7 +52,7 @@ internal static partial void LogThreadPoolWorkerThreadAdjustmentStats(
         internal static partial void LogThreadPoolIOEnqueue(
             IntPtr NativeOverlapped,
             IntPtr Overlapped,
-            bool MultiDequeues,
+            [MarshalAs(UnmanagedType.Bool)] bool MultiDequeues,
             ushort ClrInstanceID);
 
         [NonEvent]

src/coreclr/System.Private.CoreLib/src/System/GC.cs

@@ -78,7 +78,7 @@ public static GCMemoryInfo GetGCMemoryInfo(GCKind kind)
         }
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "GCInterface_StartNoGCRegion")]
-        internal static partial int _StartNoGCRegion(long totalSize, bool lohSizeKnown, long lohSize, bool disallowFullBlockingGC);
+        internal static partial int _StartNoGCRegion(long totalSize, [MarshalAs(UnmanagedType.Bool)] bool lohSizeKnown, long lohSize, [MarshalAs(UnmanagedType.Bool)] bool disallowFullBlockingGC);
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "GCInterface_EndNoGCRegion")]
         internal static partial int _EndNoGCRegion();

src/coreclr/System.Private.CoreLib/src/System/Reflection/Emit/TypeBuilder.cs

@@ -160,7 +160,7 @@ internal static partial int DefineField(QCallModule module, int tkParent, string
             FieldAttributes attributes);
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "TypeBuilder_SetMethodIL")]
-        private static partial void SetMethodIL(QCallModule module, int tk, bool isInitLocals,
+        private static partial void SetMethodIL(QCallModule module, int tk, [MarshalAs(UnmanagedType.Bool)] bool isInitLocals,
             byte[]? body, int bodyLength,
             byte[] LocalSig, int sigLength,
             int maxStackSize,

src/coreclr/System.Private.CoreLib/src/System/Reflection/LoaderAllocator.cs

@@ -26,6 +26,7 @@ internal sealed partial class LoaderAllocatorScout
         internal IntPtr m_nativeLoaderAllocator;
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "LoaderAllocator_Destroy")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         private static partial bool Destroy(IntPtr nativeLoaderAllocator);
 
         ~LoaderAllocatorScout()

src/coreclr/System.Private.CoreLib/src/System/Reflection/Metadata/MetadataUpdater.cs

@@ -13,6 +13,7 @@ public static partial class MetadataUpdater
         private static unsafe partial void ApplyUpdate(QCallAssembly assembly, byte* metadataDelta, int metadataDeltaLength, byte* ilDelta, int ilDeltaLength, byte* pdbDelta, int pdbDeltaLength);
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "AssemblyNative_IsApplyUpdateSupported")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         private static unsafe partial bool IsApplyUpdateSupported();
 
         /// <summary>

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeAssembly.cs

@@ -69,6 +69,7 @@ public override event ModuleResolveEventHandler? ModuleResolve
         }
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "AssemblyNative_GetCodeBase")]
+        [return: MarshalAs(UnmanagedType.Bool)]
         private static partial bool GetCodeBase(QCallAssembly assembly,
                                                StringHandleOnStack retString);
 
@@ -177,8 +178,8 @@ public override MethodInfo? EntryPoint
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "AssemblyNative_GetType", StringMarshalling = StringMarshalling.Utf16)]
         private static partial void GetType(QCallAssembly assembly,
                                             string name,
-                                            bool throwOnError,
-                                            bool ignoreCase,
+                                            [MarshalAs(UnmanagedType.Bool)] bool throwOnError,
+                                            [MarshalAs(UnmanagedType.Bool)] bool ignoreCase,
                                             ObjectHandleOnStack type,
                                             ObjectHandleOnStack keepAlive,
                                             ObjectHandleOnStack assemblyLoadContext);
@@ -349,7 +350,7 @@ internal static RuntimeAssembly InternalLoad(AssemblyName assemblyName,
         private static partial void InternalLoad(ObjectHandleOnStack assemblyName,
                                                 ObjectHandleOnStack requestingAssembly,
                                                 StackCrawlMarkHandle stackMark,
-                                                bool throwOnFileNotFound,
+                                                [MarshalAs(UnmanagedType.Bool)] bool throwOnFileNotFound,
                                                 ObjectHandleOnStack assemblyLoadContext,
                                                 ObjectHandleOnStack retAssembly);
 
@@ -605,8 +606,8 @@ public override Assembly GetSatelliteAssembly(CultureInfo culture!!, Version? ve
 
         [GeneratedDllImport(RuntimeHelpers.QCall, EntryPoint = "AssemblyNative_GetModules")]
         private static partial void GetModules(QCallAssembly assembly,
-                                              bool loadIfNotFound,
-                                              bool getResourceModules,
+                                              [MarshalAs(UnmanagedType.Bool)] bool loadIfNotFound,
+                                              [MarshalAs(UnmanagedType.Bool)] bool getResourceModules,
                                               ObjectHandleOnStack retModuleHandles);
 
         private RuntimeModule[] GetModulesInternal(bool loadIfNotFound,