Apply suggestions from code review

Alvaro Muñoz · owen-mc · web-flow · commit 6b3d4588657c · 2023-02-03T16:20:21.000+01:00
Co-authored-by: Owen Mansel-Chan &lt;62447351+owen-mc@users.noreply.github.com&gt;
diff --git a/go/ql/lib/semmle/go/frameworks/Twirp.qll b/go/ql/lib/semmle/go/frameworks/Twirp.qll
@@ -160,21 +160,17 @@ module Twirp {
     }
   }
 
+
   /**
-   * A request coming to the service handler
+   * A request coming to the service handler.
    */
-  class Request extends UntrustedFlowSource::Range, DataFlow::ParameterNode {
-    ServiceHandler handler;
-
+  class Request extends UntrustedFlowSource::Range instanceof DataFlow::ParameterNode {
     Request() {
-      handler.getParameter(0).getType().hasQualifiedName("context", "Context") and
-      handler.getParameter(_) = this.asParameter() and
-      this.getType().(PointerType).getBaseType() instanceof ProtobufMessageType
-    }
-
-    override predicate isParameterOf(Callable c, int i) {
-      c.asFunction() = handler and
-      i = 1
+      exists(Callable c, ServiceHandler handler | c.asFunction() = handler |
+        this.isParameterOf(c, 1) and
+        handler.getParameterType(0).hasQualifiedName("context", "Context") and
+        this.getType().(PointerType).getBaseType() instanceof ProtobufMessageType
+      )
     }
   }
 }

Original file line number	Diff line number	Diff line change
`@@ -160,21 +160,17 @@ module Twirp {`
`160`	`160`	`}`
`161`	`161`	`}`
`162`	`162`
	`163`	`+`
`163`	`164`	`/**`
`164`		`- * A request coming to the service handler`
	`165`	`+ * A request coming to the service handler.`
`165`	`166`	`*/`
`166`		`- class Request extends UntrustedFlowSource::Range, DataFlow::ParameterNode {`
`167`		`- ServiceHandler handler;`
`168`		`-`
	`167`	`+ class Request extends UntrustedFlowSource::Range instanceof DataFlow::ParameterNode {`
`169`	`168`	`Request() {`
`170`		`- handler.getParameter(0).getType().hasQualifiedName("context", "Context") and`
`171`		`- handler.getParameter(_) = this.asParameter() and`
`172`		`- this.getType().(PointerType).getBaseType() instanceof ProtobufMessageType`
`173`		`- }`
`174`		`-`
`175`		`- override predicate isParameterOf(Callable c, int i) {`
`176`		`- c.asFunction() = handler and`
`177`		`- i = 1`
	`169`	`+ exists(Callable c, ServiceHandler handler \| c.asFunction() = handler \|`
	`170`	`+ this.isParameterOf(c, 1) and`
	`171`	`+ handler.getParameterType(0).hasQualifiedName("context", "Context") and`
	`172`	`+ this.getType().(PointerType).getBaseType() instanceof ProtobufMessageType`
	`173`	`+ )`
`178`	`174`	`}`
`179`	`175`	`}`
`180`	`176`	`}`