dotnet · gewarren · Oct 9, 2024 · Oct 8, 2024 · Oct 8, 2024 · Oct 8, 2024
@@ -441,45 +441,49 @@
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1089.md",
             "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1070-1089"
         },
+        {
+            "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1090-1099.md",
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
+        },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1090.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1091.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1092.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1093.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1094.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1095.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1096.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1097.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1098.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1099.md",
-            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib1090-1099"
+            "redirect_url": "/dotnet/fundamentals/syslib-diagnostics/syslib-cominterfacegenerator"
         },
         {
             "source_path_from_root": "/docs/fundamentals/syslib-diagnostics/syslib1100.md",

@@ -167,6 +167,7 @@ The following table provides an index to the `SYSLIB1XXX` diagnostics in .NET 6
 | [SYSLIB1227][1227] | (Reserved for System.Text.Json.SourceGeneration.) |
 | [SYSLIB1228][1228] | (Reserved for System.Text.Json.SourceGeneration.) |
 | [SYSLIB1229][1229] | (Reserved for System.Text.Json.SourceGeneration.) |
+| [SYSLIB1230][1230] | Deriving from a `GeneratedComInterface`-attributed interface defined in another assembly is not supported. |
 
 <!-- Include adds ## Suppress warnings (H2 heading) -->
 [!INCLUDE [suppress-source-generator-diagnostics](includes/suppress-source-generator-diagnostics.md)]
@@ -253,16 +254,16 @@ The following table provides an index to the `SYSLIB1XXX` diagnostics in .NET 6
 [1087]: syslib1070-1089.md
 [1088]: syslib1070-1089.md
 [1089]: syslib1070-1089.md
-[1090]: syslib1090-1099.md
-[1091]: syslib1090-1099.md
-[1092]: syslib1090-1099.md
-[1093]: syslib1090-1099.md
-[1094]: syslib1090-1099.md
-[1095]: syslib1090-1099.md
-[1096]: syslib1090-1099.md
-[1097]: syslib1090-1099.md
-[1098]: syslib1090-1099.md
-[1099]: syslib1090-1099.md
+[1090]: syslib-cominterfacegenerator.md
+[1091]: syslib-cominterfacegenerator.md
+[1092]: syslib-cominterfacegenerator.md
+[1093]: syslib-cominterfacegenerator.md
+[1094]: syslib-cominterfacegenerator.md
+[1095]: syslib-cominterfacegenerator.md
+[1096]: syslib-cominterfacegenerator.md
+[1097]: syslib-cominterfacegenerator.md
+[1098]: syslib-cominterfacegenerator.md
+[1099]: syslib-cominterfacegenerator.md
 [1100]: syslib1100-1118.md
 [1101]: syslib1100-1118.md
 [1102]: syslib1100-1118.md
@@ -311,3 +312,4 @@ The following table provides an index to the `SYSLIB1XXX` diagnostics in .NET 6
 [1227]: syslib1220-1229.md
 [1228]: syslib1220-1229.md
 [1229]: syslib1220-1229.md
+[1230]: syslib1230.md
@@ -1,7 +1,7 @@
 ---
-title: SYSLIB diagnostics for Microsoft.Interop.COMInteropGenerator
-description: Learn about the COM interop source-generation analyzers that generate compile-time suggestions SYSLIB1090 through SYSLIB1099.
-ms.date: 10/28/2023
+title: SYSLIB diagnostics for Microsoft.Interop.ComInterfaceGenerator
+description: Learn about the COM interop source-generation analyzers that generate compile-time suggestions SYSLIB1090 through SYSLIB1099 and SYSLIB1230 through SYSLIB1239.
+ms.date: 10/08/2024
 f1_keywords:
   - syslib1090
   - syslib1091
@@ -16,12 +16,12 @@ f1_keywords:
 ---
 # SYSLIB diagnostics for COM interop source generation
 
-The following table shows the diagnostic IDs for COM interop source-generation analyzers in .NET 8 and later versions.
+The following table shows the diagnostic IDs for COM interop source-generation analyzers.
 
-| Diagnostic ID | Description |
-| - | - |
-|  `SYSLIB1090` | Invalid `GeneratedComInterfaceAttribute` usage. |
-|  `SYSLIB1091` | Method is declared in different partial declaration than the `GeneratedComInterface` attribute. To ensure reliable calculation for virtual method table offsets, all methods must be declared in the same partial definition of a `GeneratedComInterface`-attributed interface type. |
+| Diagnostic ID | Description                                     |
+|---------------|-------------------------------------------------|
+| `SYSLIB1090`  | Invalid `GeneratedComInterfaceAttribute` usage. |
+| `SYSLIB1091`  | Method is declared in different partial declaration than the `GeneratedComInterface` attribute. To ensure reliable calculation for virtual method table offsets, all methods must be declared in the same partial definition of a `GeneratedComInterface`-attributed interface type. |
 | `SYSLIB1092` | Usage of `LibraryImport` or `GeneratedComInterface` attribute does not follow recommendation. |
 | `SYSLIB1093` | Analysis for COM interface generation has failed. |
 | `SYSLIB1094` | The base COM interface failed to generate source. Code will not be generated for this interface. |
@@ -30,3 +30,4 @@ The following table shows the diagnostic IDs for COM interop source-generation a
 | `SYSLIB1097` | This type implements at least one type with the `GeneratedComInterfaceAttribute` attribute. Add the `GeneratedComClassAttribute` to enable passing this type to COM and exposing the COM interfaces for the types with the `GeneratedComInterfaceAttribute` from objects of this type. |
 | `SYSLIB1098` | .NET COM hosting with `EnableComHosting` only supports built-in COM interop. It does not support source-generated COM interop with `GeneratedComInterfaceAttribute`. |
 | `SYSLIB1099` | COM Interop APIs on `System.Runtime.InteropServices.Marshal` do not support source-generated COM and will fail at run time. |
+| [`SYSLIB1230`](syslib1230.md) | Deriving from a `GeneratedComInterface`-attributed interface defined in another assembly is not supported. |
@@ -0,0 +1,36 @@
+---
+title: SYSLIB1230 warning
+description: Learn about the diagnostic that generates compile-time warning SYSLIB1230.
+ms.date: 10/08/2024
+f1_keywords:
+  - syslib1230
+---
+
+# SYSLIB1230: Deriving from a `GeneratedComInterface`-attributed interface defined in another assembly is not supported
+
+In .NET 9 and later versions, defining an interface with the <xref:System.Runtime.InteropServices.Marshalling.GeneratedComInterfaceAttribute> attribute that derives from a `GeneratedComInterface`-attributed interface that's defined in another assembly is supported with the following restrictions:
+
+- The base interface type must be compiled targeting the same framework as the derived type.
+- The base interface type must not shadow any members of its base interface, if it has one.
+
+Additionally, any changes to any generated virtual method offsets in the base interface chain defined in another assembly won't be accounted for in the derived interfaces until the project is rebuilt.
+
+When you define an interface with the <xref:System.Runtime.InteropServices.Marshalling.GeneratedComInterfaceAttribute> attribute that derives from a `GeneratedComInterface`-attributed interface that's defined in another assembly, the SYSLIB1230 warning is emitted to inform you of the limitations. To acknowledge the limitations, suppress the warning in code as follows:
+
+```csharp
+// Disable the warning.
+#pragma warning disable SYSLIB1230
+[GeneratedComInterface]
+interface IDerived : IBaseInOtherAssembly
+// Re-enable the warning.
+#pragma warning restore SYSLIB1230
+{
+    // the interface definition
+}
+```
+
+[!INCLUDE [suppress-syslib-warning](includes/suppress-source-generator-diagnostics.md)]
+
+## See also
+
+- [SYSLIB diagnostics for COM interop source generation](syslib-cominterfacegenerator.md)
@@ -1879,7 +1879,7 @@ items:
             href: ../../fundamentals/syslib-diagnostics/syslib1070-1089.md
             displayProperty: syslib1071, syslib1072, syslib1073, syslib1074, syslib1075, syslib1076, syslib1077, syslib1078, syslib1079, syslib1080, syslib1081, syslib1082, syslib1083, syslib1084, syslib1085, syslib1086, syslib1087, syslib1088, syslib1089
           - name: SYSLIB1090-SYSLIB1099
-            href: ../../fundamentals/syslib-diagnostics/syslib1090-1099.md
+            href: ../../fundamentals/syslib-diagnostics/syslib-cominterfacegenerator.md
             displayProperty: syslib1091, syslib1092, syslib1093, syslib1094, syslib1095, syslib1096, syslib1097, syslib1098, syslib1099
           - name: SYSLIB1100-SYSLIB1118
             href: ../../fundamentals/syslib-diagnostics/syslib1100-1118.md
@@ -1890,6 +1890,9 @@ items:
           - name: SYSLIB1220-SYSLIB1229
             href: ../../fundamentals/syslib-diagnostics/syslib1220-1229.md
             displayProperty: syslib1220, syslib1221, syslib1222, syslib1223, syslib1224, syslib1225, syslib1226, syslib1227, syslib1228, syslib1229
+          - name: SYSLIB1230
+            href: ../../fundamentals/syslib-diagnostics/syslib1230.md
+            displayProperty: syslib1230, syslib1231, syslib1232, syslib1233, syslib1234, syslib1235, syslib1236, syslib1237, syslib1238, syslib1239
   - name: API compatibility
     items:
       - name: Overview