Attempt to implement dynamic dispatch and dynamic call linking for c/…

…c++ (#46)

Signed-off-by: Prabhu Subramanian <[email protected]>

build.sbt

@@ -1,6 +1,6 @@
 name                     := "chen"
 ThisBuild / organization := "io.appthreat"
-ThisBuild / version      := "1.1.1"
+ThisBuild / version      := "1.1.2"
 ThisBuild / scalaVersion := "3.3.1"
 
 val cpgVersion = "1.4.22"

codemeta.json

@@ -7,7 +7,7 @@
   "downloadUrl": "https://github.com/AppThreat/chen",
   "issueTracker": "https://github.com/AppThreat/chen/issues",
   "name": "chen",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "description": "Code Hierarchy Exploration Net (chen) is an advanced exploration toolkit for your application source code and its dependency hierarchy.",
   "applicationCategory": "code-analysis",
   "keywords": [

meta.yaml

@@ -1,4 +1,4 @@
-{% set version = "1.1.1" %}
+{% set version = "1.1.2" %}
 
 package:
   name: chen

platform/frontends/c2cpg/src/main/scala/io/appthreat/c2cpg/astcreation/AstCreatorHelper.scala

@@ -1,12 +1,10 @@
 package io.appthreat.c2cpg.astcreation
 
 import io.appthreat.c2cpg.datastructures.CGlobal
-import io.appthreat.c2cpg.parser.FileDefaults
-import io.shiftleft.codepropertygraph.generated.nodes.{ExpressionNew, NewNode}
-import io.shiftleft.codepropertygraph.generated.{DispatchTypes, Operators}
-import io.appthreat.x2cpg.{Ast, SourceFiles, ValidationMode}
 import io.appthreat.x2cpg.utils.NodeBuilders.newDependencyNode
-import io.shiftleft.codepropertygraph.generated.EdgeTypes
+import io.appthreat.x2cpg.{Ast, SourceFiles, ValidationMode}
+import io.shiftleft.codepropertygraph.generated.nodes.{ExpressionNew, NewNode}
+import io.shiftleft.codepropertygraph.generated.{DispatchTypes, EdgeTypes, Operators}
 import io.shiftleft.utils.IOUtils
 import org.apache.commons.lang.StringUtils
 import org.eclipse.cdt.core.dom.ast.*
@@ -18,12 +16,8 @@ import org.eclipse.cdt.core.dom.ast.c.{
 import org.eclipse.cdt.core.dom.ast.cpp.*
 import org.eclipse.cdt.core.dom.ast.gnu.c.ICASTKnRFunctionDeclarator
 import org.eclipse.cdt.internal.core.dom.parser.c.CASTArrayRangeDesignator
-import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalBinding
-import org.eclipse.cdt.internal.core.dom.parser.cpp.{CPPASTIdExpression, CPPFunction}
-import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPASTArrayRangeDesignator
-import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalMemberAccess
-import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPASTFieldReference
-import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPMethod
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.{EvalBinding, EvalMemberAccess}
+import org.eclipse.cdt.internal.core.dom.parser.cpp.*
 import org.eclipse.cdt.internal.core.model.ASTStringUtil
 
 import java.nio.file.{Path, Paths}

platform/frontends/c2cpg/src/main/scala/io/appthreat/c2cpg/astcreation/AstForExpressionsCreator.scala

@@ -50,9 +50,16 @@ trait AstForExpressionsCreator(implicit withSchemaValidation: ValidationMode):
             case IASTBinaryExpression.op_ellipses        => "<operator>.op_ellipses"
             case _                                       => "<operator>.unknown"
 
-        val callNode_ = callNode(bin, nodeSignature(bin), op, op, DispatchTypes.STATIC_DISPATCH)
-        val left      = nullSafeAst(bin.getOperand1)
-        val right     = nullSafeAst(bin.getOperand2)
+        val callNode_ = callNode(
+          bin,
+          nodeSignature(bin),
+          op,
+          op,
+          if op == Operators.indirectFieldAccess then DispatchTypes.DYNAMIC_DISPATCH
+          else DispatchTypes.STATIC_DISPATCH
+        )
+        val left  = nullSafeAst(bin.getOperand1)
+        val right = nullSafeAst(bin.getOperand2)
         callAst(callNode_, List(left, right))
     end astForBinaryExpression
 
@@ -91,7 +98,7 @@ trait AstForExpressionsCreator(implicit withSchemaValidation: ValidationMode):
         val (dd, name) = call.getFunctionNameExpression match
             case _: ICPPASTLambdaExpression =>
                 (
-                  DispatchTypes.STATIC_DISPATCH,
+                  DispatchTypes.DYNAMIC_DISPATCH,
                   rec.root.get.asInstanceOf[NewMethodRef].methodFullName
                 )
             case _ if rec.root.exists(_.isInstanceOf[NewIdentifier]) =>
@@ -164,7 +171,9 @@ trait AstForExpressionsCreator(implicit withSchemaValidation: ValidationMode):
                   nodeSignature(unary),
                   operatorMethod,
                   operatorMethod,
-                  DispatchTypes.STATIC_DISPATCH
+                  if operatorMethod == Operators.addressOf || operatorMethod == Operators.indirectFieldAccess
+                  then DispatchTypes.DYNAMIC_DISPATCH
+                  else DispatchTypes.STATIC_DISPATCH
                 )
             val operand = nullSafeAst(unary.getOperand)
             callAst(cpgUnary, List(operand))

platform/frontends/c2cpg/src/main/scala/io/appthreat/c2cpg/astcreation/AstForPrimitivesCreator.scala

@@ -92,7 +92,14 @@ trait AstForPrimitivesCreator(implicit withSchemaValidation: ValidationMode):
     protected def astForFieldReference(fieldRef: IASTFieldReference): Ast =
         val op = if fieldRef.isPointerDereference then Operators.indirectFieldAccess
         else Operators.fieldAccess
-        val ma = callNode(fieldRef, nodeSignature(fieldRef), op, op, DispatchTypes.STATIC_DISPATCH)
+        val ma = callNode(
+          fieldRef,
+          nodeSignature(fieldRef),
+          op,
+          op,
+          if fieldRef.isPointerDereference then DispatchTypes.DYNAMIC_DISPATCH
+          else DispatchTypes.STATIC_DISPATCH
+        )
         val owner = astForExpression(fieldRef.getFieldOwner)
         val member = fieldIdentifierNode(
           fieldRef,

platform/frontends/c2cpg/src/main/scala/io/appthreat/c2cpg/astcreation/AstForTypesCreator.scala

@@ -120,16 +120,21 @@ trait AstForTypesCreator(implicit withSchemaValidation: ValidationMode):
         init match
             case i: IASTEqualsInitializer =>
                 val operatorName = Operators.assignment
+                val left         = astForNode(declarator.getName)
+                val right        = astForNode(i.getInitializerClause)
+                val code         = i.getInitializerClause.getRawSignature;
+                val dispatchType =
+                    if code.nonEmpty && (code.startsWith("&") || code.contains("->")) then
+                        DispatchTypes.DYNAMIC_DISPATCH
+                    else DispatchTypes.STATIC_DISPATCH
                 val callNode_ =
                     callNode(
                       declarator,
                       nodeSignature(declarator),
                       operatorName,
                       operatorName,
-                      DispatchTypes.STATIC_DISPATCH
+                      dispatchType
                     )
-                val left  = astForNode(declarator.getName)
-                val right = astForNode(i.getInitializerClause)
                 callAst(callNode_, List(left, right))
             case i: ICPPASTConstructorInitializer =>
                 val name = ASTStringUtil.getSimpleName(declarator.getName)

platform/frontends/c2cpg/src/test/scala/io/appthreat/c2cpg/passes/ast/AstCreationPassTests.scala

@@ -310,7 +310,7 @@ class AstCreationPassTests extends AbstractPassTest {
       inside(cpg.call(lambda2Name).l) { case List(lambda2call) =>
         lambda2call.name shouldBe lambda2Name
         lambda2call.methodFullName shouldBe lambda2Name
-        // TODO: lambda2call.dispatchType shouldBe DispatchTypes.DYNAMIC_DISPATCH
+        lambda2call.dispatchType shouldBe DispatchTypes.DYNAMIC_DISPATCH
         inside(lambda2call.astChildren.l) { case List(ref: MethodRef, lit: Literal) =>
           ref.methodFullName shouldBe lambda2Name
           ref.code should startWith("[](int n) -> int")

platform/frontends/c2cpg/src/test/scala/io/appthreat/c2cpg/querying/CallGraphQueryTests.scala

@@ -47,4 +47,46 @@ class CallGraphQueryTests extends CCodeToCpgSuite {
     cpg.method.name("printf").callIn.argument.inCall.name.toSetMutable shouldBe Set("printf")
   }
 
+    "CallTest 6" should {
+        val cpg = code(
+            """
+              |class Animal {
+              |	public:
+              |    virtual void eat() {
+              |		std::cout<<"eat nothing";
+              |	}
+              |};
+              |class Cat:public Animal {
+              |    public:
+              |	void eat() {
+              |        std::cout<<"eat fish";
+              |    }
+              |};
+              |class People {
+              |  Cat d;
+              |  Animal *pet = &d;
+              |  void eat() {
+              |    std::cout<<"people eat";
+              |  }
+              |  void feedPets() {
+              |    pet->eat();
+              |  }
+              |}
+              |int main( )
+              |{
+              |   Cat c;
+              |   Animal *a = &c;
+              |   a->eat();
+              |   return 0;
+              |}
+              |""".stripMargin,
+            "test.cpp"
+        )
+        "have correct type full names for calls" in {
+            cpg.method.name("eat").fullName.toSet shouldBe Set("Animal.eat", "Cat.eat", "People.eat")
+            cpg.method.fullName("main").callee.fullName.toSet shouldBe Set("Animal.eat", "Cat.eat")
+            cpg.method.fullName("Cat.eat").caller.fullName.toSet shouldBe Set("main")
+            cpg.method.fullName("Animal.eat").caller.fullName.toSet shouldBe Set("People.feedPets", "main")
+        }
+    }
 }

platform/frontends/x2cpg/src/main/scala/io/appthreat/x2cpg/passes/callgraph/DynamicCallLinker.scala

@@ -135,10 +135,13 @@ class DynamicCallLinker(cpg: Cpg) extends CpgPass(cpg):
             case None => None
 
     private def resolveCallInSuperClasses(call: Call): Boolean =
-        if !call.methodFullName.contains(":") then return false
+        if !call.methodFullName.contains(":") && !call.methodFullName.contains(".") then
+            return false
         def split(str: String, n: Int) = (str.take(n), str.drop(n + 1))
-        val (fullName, signature) = split(call.methodFullName, call.methodFullName.lastIndexOf(":"))
-        val typeDeclFullName      = fullName.replace(s".${call.name}", "")
+        val (fullName, signature) = if call.methodFullName.contains(":") then
+            split(call.methodFullName, call.methodFullName.lastIndexOf(":"))
+        else split(call.methodFullName, call.methodFullName.lastIndexOf("."))
+        val typeDeclFullName = fullName.replace(s".${call.name}", "")
         val candidateInheritedMethods =
             cpg.typeDecl
                 .fullNameExact(allSuperClasses(typeDeclFullName).toIndexedSeq*)
@@ -159,8 +162,30 @@ class DynamicCallLinker(cpg: Cpg) extends CpgPass(cpg):
               )
             )
             true
+        else if call.methodFullName == "<operator>.indirectFieldAccess" then
+            val calledMethodName = call.argument.last.code
+            val fieldTypes       = call.argument.head.typ.l
+            fieldTypes.foreach { ft =>
+                val ftSubClasses = allSubclasses(ft.fullName).filterNot(cn => cn == ft.fullName)
+                if ftSubClasses.nonEmpty then
+                    val candidateSubTypeMethods = cpg.typeDecl.fullNameExact(
+                      ftSubClasses.toIndexedSeq*
+                    ).astChildren.isMethod.name(calledMethodName).fullName.l
+                    if candidateSubTypeMethods.nonEmpty then
+                        validM.put(
+                          calledMethodName,
+                          validM.getOrElse(
+                            calledMethodName,
+                            mutable.LinkedHashSet.empty
+                          ) ++ mutable.LinkedHashSet.from(
+                            candidateSubTypeMethods
+                          )
+                        )
+            }
+            true
         else
             false
+        end if
     end resolveCallInSuperClasses
 
     private def linkDynamicCall(call: Call, dstGraph: DiffGraphBuilder): Unit =
@@ -170,9 +195,11 @@ class DynamicCallLinker(cpg: Cpg) extends CpgPass(cpg):
             )
         then return
         // Support for overriding
-        resolveCallInSuperClasses(call)
-
-        validM.get(call.methodFullName) match
+        val resolved        = resolveCallInSuperClasses(call)
+        var methodNameToUse = call.methodFullName
+        if call.methodFullName.startsWith("<operator>") && resolved then
+            methodNameToUse = call.argument.last.code
+        validM.get(methodNameToUse) match
             case Some(tgts) =>
                 val callsOut = call.callOut.fullName.toSetImmutable
                 val tgtMs = tgts

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "appthreat-chen"
-version = "1.1.1"
+version = "1.1.2"
 description = "Code Hierarchy Exploration Net (chen)"
 authors = ["Team AppThreat <[email protected]>"]
 license = "Apache-2.0"