C#: Convert System.IO.Compression flow to CSV format.

csharp/ql/lib/semmle/code/csharp/dataflow/ExternalFlow.qll

@@ -99,6 +99,7 @@ private module Frameworks {
   private import semmle.code.csharp.frameworks.system.web.ui.WebControls
   private import semmle.code.csharp.frameworks.JsonNET
   private import semmle.code.csharp.frameworks.system.IO
+  private import semmle.code.csharp.frameworks.system.io.Compression
 }
 
 /**

csharp/ql/lib/semmle/code/csharp/dataflow/LibraryTypeDataFlow.qll

@@ -1779,24 +1779,6 @@ library class SystemTextEncodingFlow extends LibraryTypeDataFlow, SystemTextEnco
   }
 }
 
-/** Data flow for `System.IO.Compression.DeflateStream`. */
-class SystemIOCompressionDeflateStreamFlow extends LibraryTypeDataFlow,
-  SystemIOCompressionDeflateStream {
-  override predicate callableFlow(
-    CallableFlowSource source, CallableFlowSink sink, SourceDeclarationCallable c,
-    boolean preservesValue
-  ) {
-    this.constructorFlow(source, sink, c) and
-    preservesValue = false
-  }
-
-  private predicate constructorFlow(CallableFlowSource source, CallableFlowSink sink, Constructor c) {
-    c = this.getAMember() and
-    source = TCallableFlowSourceArg(0) and
-    sink = TCallableFlowSinkReturn()
-  }
-}
-
 /** Data flow for `System.Xml.XmlReader`. */
 class SystemXmlXmlReaderFlow extends LibraryTypeDataFlow, SystemXmlXmlReaderClass {
   override predicate callableFlow(

csharp/ql/lib/semmle/code/csharp/frameworks/system/io/Compression.qll

@@ -2,6 +2,7 @@
 
 import csharp
 private import semmle.code.csharp.frameworks.system.IO
+private import semmle.code.csharp.dataflow.ExternalFlow
 
 /** The `System.IO.Compression` namespace. */
 class SystemIOCompressionNamespace extends Namespace {
@@ -20,3 +21,16 @@ class SystemIOCompressionClass extends Class {
 class SystemIOCompressionDeflateStream extends SystemIOCompressionClass {
   SystemIOCompressionDeflateStream() { this.hasName("DeflateStream") }
 }
+
+/** Data flow for `System.IO.Compression.DeflateStream`. */
+private class SystemIOCompressionDeflateStreamFlowModelCsv extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        "System.IO.Compression;DeflateStream;false;DeflateStream;(System.IO.Stream,System.IO.Compression.CompressionLevel);;Argument[0];ReturnValue;taint",
+        "System.IO.Compression;DeflateStream;false;DeflateStream;(System.IO.Stream,System.IO.Compression.CompressionLevel,System.Boolean);;Argument[0];ReturnValue;taint",
+        "System.IO.Compression;DeflateStream;false;DeflateStream;(System.IO.Stream,System.IO.Compression.CompressionMode);;Argument[0];ReturnValue;taint",
+        "System.IO.Compression;DeflateStream;false;DeflateStream;(System.IO.Stream,System.IO.Compression.CompressionMode,System.Boolean);;Argument[0];ReturnValue;taint"
+      ]
+  }
+}