Merge pull request #3245 from AlekseyTs/Bug1129404

Check current language version for “Global” keyword only if it starts namespace name in namespace declaration.

src/Compilers/VisualBasic/Portable/Parser/Parser.vb

@@ -158,7 +158,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
                             Optional nonArrayName As Boolean = False,
                             Optional disallowGenericArgumentsOnLastQualifiedName As Boolean = False,
                             Optional allowEmptyGenericArguments As Boolean = False,
-                            Optional ByRef allowedEmptyGenericArguments As Boolean = False
+                            Optional ByRef allowedEmptyGenericArguments As Boolean = False,
+                            Optional isNameInNamespaceDeclaration As Boolean = False
                         ) As NameSyntax
 
             Debug.Assert(allowGenericArguments OrElse Not allowEmptyGenericArguments, "Inconsistency in generic arguments parsing requirements!!!")
@@ -171,7 +172,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
             If CurrentToken.Kind = SyntaxKind.GlobalKeyword Then
 
                 result = SyntaxFactory.GlobalName(DirectCast(CurrentToken, KeywordSyntax))
-                result = CheckFeatureAvailability(Feature.GlobalNamespace, result)
+
+                If isNameInNamespaceDeclaration Then
+                    result = CheckFeatureAvailability(Feature.GlobalNamespace, result)
+                End If
 
                 GetNextToken()
 
@@ -1641,7 +1645,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
                 requireQualification:=False,
                 allowGlobalNameSpace:=True,
                 allowGenericArguments:=False,
-                allowGenericsWithoutOf:=True)
+                allowGenericsWithoutOf:=True,
+                isNameInNamespaceDeclaration:=True)
 
             If namespaceName.ContainsDiagnostics Then
                 ' Resync at EOS so we don't get expecting EOS errors

src/Compilers/VisualBasic/Test/Syntax/Parser/ParseLanguageVersionTests.vb

@@ -234,4 +234,69 @@ End Class
             Diagnostic(ERRID.ERR_LanguageVersion, "?").WithArguments("9.0", "null conditional operations").WithLocation(4, 31),
             Diagnostic(ERRID.ERR_LanguageVersion, "?").WithArguments("9.0", "null conditional operations").WithLocation(5, 22))
     End Sub
+
+    <[Fact]>
+    Public Sub GlobalKeyword_01()
+        Dim source = "
+Imports System
+
+Namespace Global
+    Module Program
+
+        Sub Main()
+        End Sub
+
+    End Module
+End Namespace"
+
+        For Each version In {LanguageVersion.VisualBasic9, LanguageVersion.VisualBasic10}
+            ParseAndVerify(source, version,
+                Diagnostic(ERRID.ERR_LanguageVersion, "Global").WithArguments($"{CInt(version)}.0", "declaring a Global namespace").WithLocation(4, 11))
+        Next
+
+        For Each version In {LanguageVersion.VisualBasic11, LanguageVersion.VisualBasic12, LanguageVersion.VisualBasic14, VisualBasicParseOptions.Default.LanguageVersion}
+            ParseAndVerify(source, version, False, Nothing)
+        Next
+    End Sub
+
+    <[Fact]>
+    Public Sub GlobalKeyword_02()
+        Dim source = "
+Module Program
+    Function getValue() As Global.System.Int32
+        Return 14
+    End Function
+End Module"
+
+        For Each version In {LanguageVersion.VisualBasic9, LanguageVersion.VisualBasic10,
+                             LanguageVersion.VisualBasic11, LanguageVersion.VisualBasic12,
+                             LanguageVersion.VisualBasic14, VisualBasicParseOptions.Default.LanguageVersion}
+            ParseAndVerify(source, version, False, Nothing)
+        Next
+    End Sub
+
+    <[Fact]>
+    Public Sub GlobalKeyword_03()
+        Dim source = "
+Imports System
+
+Namespace Global.Ns1
+    Module Program
+
+        Sub Main()
+        End Sub
+
+    End Module
+End Namespace"
+
+        For Each version In {LanguageVersion.VisualBasic9, LanguageVersion.VisualBasic10}
+            ParseAndVerify(source, version,
+                Diagnostic(ERRID.ERR_LanguageVersion, "Global").WithArguments($"{CInt(version)}.0", "declaring a Global namespace").WithLocation(4, 11))
+        Next
+
+        For Each version In {LanguageVersion.VisualBasic11, LanguageVersion.VisualBasic12, LanguageVersion.VisualBasic14, VisualBasicParseOptions.Default.LanguageVersion}
+            ParseAndVerify(source, version, False, Nothing)
+        Next
+    End Sub
+
 End Class
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