Add CFG check for branch extensions.

src/Compilers/Core/Portable/CodeAnalysisResources.Designer.cs

@@ -1081,6 +1081,15 @@ internal class CodeAnalysisResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to The provided operation must not be part of a Control Flow Graph..
+        /// </summary>
+        internal static string OperationMustNotBeControlFlowGraphPart {
+            get {
+                return ResourceManager.GetString("OperationMustNotBeControlFlowGraphPart", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Output kind not supported..
         /// </summary>

src/Compilers/Core/Portable/CodeAnalysisResources.resx

@@ -630,4 +630,7 @@
   <data name="InvalidBranchKindForFindingCorrespondingSwitch" xml:space="preserve">
     <value>Invalid branch kind. Finding a corresponding switch requires 'break' kind, but the current branch kind provided is '{0}'.</value>
   </data>
+  <data name="OperationMustNotBeControlFlowGraphPart" xml:space="preserve">
+    <value>The provided operation must not be part of a Control Flow Graph.</value>
+  </data>
 </root>
\ No newline at end of file

src/Compilers/Core/Portable/Operations/OperationExtensions.cs

@@ -330,7 +330,8 @@ internal static IOperation GetRootOperation(this IOperation operation)
         /// <returns>The corresponding loop operation or <c>null</c> in case not found (e.g. no loop syntax or the branch
         /// belongs to switch instead of loop operation)</returns>
         /// <exception cref="ArgumentNullException"><paramref name="branchOperation"/> is null</exception>
-        /// <exception cref="InvalidOperationException">Invalid branch kind. Applicable kinds: <see cref="BranchKind.Break"/> and <see cref="BranchKind.Continue"/>.</exception>
+        /// <exception cref="InvalidOperationException">The operation is a part of Control Flow Graph or it has an invalid branch kind. 
+        /// Applicable kinds: <see cref="BranchKind.Break"/> and <see cref="BranchKind.Continue"/>.</exception>
         public static ILoopOperation GetCorrespondingLoop(this IBranchOperation branchOperation)
         {
             if (branchOperation == null)
@@ -338,6 +339,11 @@ public static ILoopOperation GetCorrespondingLoop(this IBranchOperation branchOp
                 throw new ArgumentNullException(nameof(branchOperation));
             }
 
+            if (branchOperation.SemanticModel == null)
+            {
+                throw new InvalidOperationException(CodeAnalysisResources.OperationMustNotBeControlFlowGraphPart);
+            }
+
             if (branchOperation.BranchKind != BranchKind.Break && branchOperation.BranchKind != BranchKind.Continue)
             {
                 throw new InvalidOperationException(
@@ -355,7 +361,8 @@ public static ILoopOperation GetCorrespondingLoop(this IBranchOperation branchOp
         /// <returns>The corresponding switch operation or <c>null</c> in case not found (e.g. no switch syntax or the branch
         /// belongs to loop instead of switch operation)</returns>
         /// <exception cref="ArgumentNullException"><paramref name="branchOperation"/> is null</exception>
-        /// <exception cref="InvalidOperationException">Invalid branch kind. Applicable kinds: <see cref="BranchKind.Break"/>.</exception>
+        /// <exception cref="InvalidOperationException">The operation is a part of Control Flow Graph or it has an invalid branch kind. 
+        /// Applicable kinds: <see cref="BranchKind.Break"/>.</exception>
         public static ISwitchOperation GetCorrespondingSwitch(this IBranchOperation branchOperation)
         {
             if (branchOperation == null)
@@ -363,6 +370,11 @@ public static ISwitchOperation GetCorrespondingSwitch(this IBranchOperation bran
                 throw new ArgumentNullException(nameof(branchOperation));
             }
 
+            if (branchOperation.SemanticModel == null)
+            {
+                throw new InvalidOperationException(CodeAnalysisResources.OperationMustNotBeControlFlowGraphPart);
+            }
+
             if (branchOperation.BranchKind != BranchKind.Break)
             {
                 throw new InvalidOperationException(

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.cs.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Druh výstupu se nepodporuje.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.de.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Ausgabetyp wird nicht unterstützt.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.es.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Tipo de salida no admitida.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.fr.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Type de sortie non pris en charge.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.it.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Il tipo di output non è supportato.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ja.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">出力の種類がサポートされていません。</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ko.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">출력 종류가 지원되지 않습니다.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pl.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Rodzaj wyjścia nie jest obsługiwany.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.pt-BR.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Tipo de saída sem suporte.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.ru.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Неподдерживаемый тип выходных данных.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.tr.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">Çıkış türü desteklenmiyor.</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hans.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">输出类型不受支持。</target>

src/Compilers/Core/Portable/xlf/CodeAnalysisResources.zh-Hant.xlf

@@ -34,6 +34,11 @@
         <target state="new">Given operation has a null semantic model.</target>
         <note />
       </trans-unit>
+      <trans-unit id="OperationMustNotBeControlFlowGraphPart">
+        <source>The provided operation must not be part of a Control Flow Graph.</source>
+        <target state="new">The provided operation must not be part of a Control Flow Graph.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="OutputKindNotSupported">
         <source>Output kind not supported.</source>
         <target state="translated">輸出種類不支援。</target>