Avoid pseudo-errors in C# output

We used VS Code's C# languageId before, which triggered several C#
features we didn't need, sometimes showing red pseudo-errors in editor.
We avoid that now by defining an own ILSpy languageId, which re-uses VS
Code's built-in grammar for proper syntax highlighting, but nothing else
C#-related.

Author: Rpinski

vscode-extension/package.json

@@ -684,6 +684,27 @@
 					}
 				}
 			}
+		],
+		"languages": [
+			{
+				"id": "ilspy-code-cs",
+				"aliases": [
+					"ILSpy (C#)"
+				]
+			},
+			{
+				"id": "ilspy-code-il",
+				"aliases": [
+					"ILSpy (IL)"
+				]
+			}
+		],
+		"grammars": [
+			{
+				"language": "ilspy-code-cs",
+				"scopeName": "source.ilspy-code-cs",
+				"path": "resources/ilspy-code-cs.tmLanguage.json"
+			}
 		]
 	},
 	"scripts": {

vscode-extension/resources/ilspy-code-cs.tmLanguage.json

@@ -0,0 +1,8 @@
+{
+	"scopeName": "source.ilspy-code-cs",
+	"patterns": [
+		{
+			"include": "source.cs"
+		}
+	]
+}

vscode-extension/src/decompiler/languageInfos.ts

@@ -1,97 +1,104 @@
 import { LanguageName } from "../protocol/LanguageName";
 
+const ILSPY_CODE_CS_LANG = "ilspy-code-cs";
+const ILSPY_CODE_IL_LANG = "ilspy-code-il";
+
 export interface LanguageInfo {
   name: LanguageName;
   displayName: string;
   vsLanguageMode: string;
 }
 
 export const languageInfos = createLanguageMap([
-  { name: LanguageName.IL, displayName: "IL", vsLanguageMode: "il" },
+  {
+    name: LanguageName.IL,
+    displayName: "IL",
+    vsLanguageMode: ILSPY_CODE_IL_LANG,
+  },
   {
     name: LanguageName.CSharp_1,
     displayName: "C# 1.0 / VS .NET",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_2,
     displayName: "C# 2.0 / VS 2005",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_3,
     displayName: "C# 3.0 / VS 2008",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_4,
     displayName: "C# 4.0 / VS 2010",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_5,
     displayName: "C# 5.0 / VS 2012",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_6,
     displayName: "C# 6.0 / VS 2015",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_7,
     displayName: "C# 7.0 / VS 2017",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_7_1,
     displayName: "C# 7.1 / VS 2017.3",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_7_2,
     displayName: "C# 7.2 / VS 2017.4",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_7_3,
     displayName: "C# 7.3 / VS 2017.7",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_8,
     displayName: "C# 8.0 / VS 2019",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_9,
     displayName: "C# 9.0 / VS 2019.8",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_10,
     displayName: "C# 10.0 / VS 2022",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_11,
     displayName: "C# 11.0 / VS 2022.4",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_12,
     displayName: "C# 12.0 / VS 2022.8",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_13,
     displayName: "C# 13.0 / VS 2022.12",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
   {
     name: LanguageName.CSharp_14,
     displayName: "C# 14.0 / VS 2026",
-    vsLanguageMode: "csharp",
+    vsLanguageMode: ILSPY_CODE_CS_LANG,
   },
 ]);