[c#] take into account global using directives

joern-cli/frontends/csharpsrc2cpg/src/main/scala/io/joern/csharpsrc2cpg/astcreation/AstSummaryVisitor.scala

@@ -58,6 +58,8 @@ trait AstSummaryVisitor(implicit withSchemaValidation: ValidationMode) { this: A
 
     def imports = cpg.imports.importedEntity.toSet
 
+    def globalImports = cpg.imports.filter(_.code.startsWith("global")).importedEntity.toSet
+
     def toMethod(m: Method): CSharpMethod = {
       CSharpMethod(
         m.name,
@@ -78,7 +80,7 @@ trait AstSummaryVisitor(implicit withSchemaValidation: ValidationMode) { this: A
         })
       })
       .asInstanceOf[NamespaceToTypeMap]
-    CSharpProgramSummary(mapping, imports)
+    CSharpProgramSummary(mapping, imports, globalImports)
   }
 
 }

joern-cli/frontends/csharpsrc2cpg/src/main/scala/io/joern/csharpsrc2cpg/datastructures/CSharpProgramSummary.scala

@@ -10,7 +10,6 @@ import upickle.default.*
 
 import java.io.{ByteArrayInputStream, InputStream}
 import scala.annotation.targetName
-import scala.collection.mutable.ListBuffer
 import scala.io.Source
 import scala.util.{Failure, Success, Try}
 import java.net.JarURLConnection
@@ -27,14 +26,19 @@ type NamespaceToTypeMap = mutable.Map[String, mutable.Set[CSharpType]]
   * @see
   *   [[CSharpProgramSummary.jsonToInitialMapping]] for generating initial mappings.
   */
-case class CSharpProgramSummary(namespaceToType: NamespaceToTypeMap, imports: Set[String])
+case class CSharpProgramSummary(namespaceToType: NamespaceToTypeMap, imports: Set[String], globalImports: Set[String])
     extends ProgramSummary[CSharpType, CSharpMethod, CSharpField] {
 
-  def findGlobalTypes: Set[CSharpType] = namespaceToType.getOrElse(Constants.Global, Set.empty).toSet
+  def findGlobalTypes: Set[CSharpType] =
+    (globalImports ++ Set(Constants.Global)).flatMap(namespaceToType.getOrElse(_, Set.empty))
 
   @targetName("appendAll")
   def ++=(other: CSharpProgramSummary): CSharpProgramSummary = {
-    new CSharpProgramSummary(ProgramSummary.merge(namespaceToType, other.namespaceToType), imports ++ other.imports)
+    new CSharpProgramSummary(
+      ProgramSummary.merge(namespaceToType, other.namespaceToType),
+      imports ++ other.imports,
+      globalImports ++ other.globalImports
+    )
   }
 
 }
@@ -47,9 +51,10 @@ object CSharpProgramSummary {
 
   def apply(
     namespaceToType: NamespaceToTypeMap = mutable.Map.empty,
-    imports: Set[String] = Set.empty
+    imports: Set[String] = Set.empty,
+    globalImports: Set[String] = Set.empty
   ): CSharpProgramSummary =
-    new CSharpProgramSummary(namespaceToType, imports)
+    new CSharpProgramSummary(namespaceToType, imports, globalImports)
 
   def apply(summaries: Iterable[CSharpProgramSummary]): CSharpProgramSummary =
     summaries.foldLeft(CSharpProgramSummary())(_ ++= _)

joern-cli/frontends/csharpsrc2cpg/src/test/scala/io/joern/csharpsrc2cpg/querying/ast/UsingDirectiveTests.scala

@@ -0,0 +1,59 @@
+package io.joern.csharpsrc2cpg.querying.ast
+
+import io.joern.csharpsrc2cpg.testfixtures.CSharpCode2CpgFixture
+import io.shiftleft.semanticcpg.language.*
+
+class UsingDirectiveTests extends CSharpCode2CpgFixture {
+
+  "`global using` directive in another file" should {
+    val cpg = code("""
+        |class Foo
+        |{
+        | static void Run()
+        | {
+        |   Console.WriteLine("Hello");
+        | }
+        |}""".stripMargin)
+      .moreCode(
+        """
+          |global using System;
+          |""".stripMargin,
+        "globals.cs"
+      )
+
+    "make the imported namespace available in the current file" in {
+      inside(cpg.call("WriteLine").l) {
+        case writeLine :: Nil =>
+          writeLine.methodFullName shouldBe "System.Console.WriteLine:System.Void(System.String)"
+        case xs =>
+          fail(s"Expected single WriteLine call, but found $xs")
+      }
+    }
+  }
+
+  "`using` directive in another file" should {
+    val cpg = code("""
+        |class Foo
+        |{
+        | static void Run()
+        | {
+        |   Console.WriteLine("Hello");
+        | }
+        |}""".stripMargin)
+      .moreCode(
+        """
+          |using System;
+          |""".stripMargin,
+        "dummy.cs"
+      )
+
+    "not affect the imported namespaces in the current file" in {
+      inside(cpg.call("WriteLine").l) {
+        case writeLine :: Nil =>
+          writeLine.methodFullName shouldBe "<unresolvedNamespace>.WriteLine:<unresolvedSignature>"
+        case xs =>
+          fail(s"Expected single WriteLine call, but found $xs")
+      }
+    }
+  }
+}