Question about missing DFG edges when generating CPG from C++ code

[kimchangsu9487]

Hello — and first of all, thank you for your hard work on this project. I really appreciate the effort you’ve put into developing and maintaining it.

I’m using this project for research to analyze C++ code. I wrote the following Kotlin snippet to extract the CPG, DFG, and related structures from C++ sources:

Kotlin Code

val cppLang = CPPLanguage()

// include C++ front-end
val translationConfig = TranslationConfiguration.builder()
    .sourceLocations(listOf(sourceDir))
    .registerLanguage("de.fraunhofer.aisec.cpg.frontends.cxx.CPPLanguage")
    .defaultPasses()                  // register default pass
    .debugParser(false)
    .failOnError(true)
    .build()

// TranslationManager → CPG 생성
val manager = TranslationManager.builder().config(translationConfig ).build()
val result = manager.analyze().get()  // Future.get()

I noticed that Codyze creates many nodes in DirtyNode, but I don’t see any CPG/DFG edges in the result.
What I expected was the data flow graph edges described on this page:
https://github.com/Fraunhofer-AISEC/cpg/blob/main/docs/docs/CPG/specs/dfg.md

Is there something I’m missing or a configuration/pass I need to enable to get DFG edges?
Thanks in advance for any pointers or suggestions.

Best regards,
CS Kim

Analysis Result (TranslationManager Analyze Result)

additionalNodes: []
benchmarks: [de.fraunhofer.aisec.cpg.helpers.Benchmark@636e1bcd, de.fraunhofer.aisec.cpg.helpers.Benchmark@29443ae9, de.fraunhofer.aisec.cpg.helpers.Benchmark@1ac16861, de.fraunhofer.aisec.cpg.helpers.Benchmark@6f4757a2, de.fraunhofer.aisec.cpg.helpers.Benchmark@836a205, de.fraunhofer.aisec.cpg.helpers.Benchmark@4eb3f1fa, de.fraunhofer.aisec.cpg.helpers.Benchmark@5e4b04a9, de.fraunhofer.aisec.cpg.helpers.Benchmark@7b7d41e8, de.fraunhofer.aisec.cpg.helpers.Benchmark@51852fb9, de.fraunhofer.aisec.cpg.helpers.Benchmark@56238536, de.fraunhofer.aisec.cpg.helpers.Benchmark@59c12ff0, de.fraunhofer.aisec.cpg.helpers.Benchmark@52f1e504, de.fraunhofer.aisec.cpg.helpers.Benchmark@481b12e7]
componentDependencies: {Component[name=application,location=]=de.fraunhofer.aisec.cpg.helpers.IdentitySet@0}
componentEdges: [AstEdge[end=Component[name=application,location=]]]
components: [Component[name=application,location=]]
config:
{"addIncludesToGraph":true,"codeInNodes":true,"compilationDatabase":null,"debugParser":false,"disableCleanup":false,"disableTypeObserver":false,"exclusionPatternsByRegex":[],"exclusionPatternsByString":[],"failOnError":true,"functionSummaries":"de.fraunhofer.aisec.cpg.passes.inference.DFGFunctionSummaries@48e7b3d2","includeBlocklist":[],"includePaths":[],"includeWhitelist":[],"inferenceConfiguration":{"inferRecords":true,"inferDfgForUnresolvedCalls":true},"languages":["class de.fraunhofer.aisec.cpg.frontends.cxx.CPPLanguage"],"loadIncludes":false,"matchCommentsToNodes":false,"maxPassExecutions":5,"passConfigurations":{},"processAnnotations":false,"registeredPasses":[["class de.fraunhofer.aisec.cpg.passes.ImportResolver"],["class de.fraunhofer.aisec.cpg.passes.TypeResolver","class de.fraunhofer.aisec.cpg.passes.ResolveMemberExpressionAmbiguityPass"],["class de.fraunhofer.aisec.cpg.passes.TypeHierarchyResolver","class de.fraunhofer.aisec.cpg.passes.CXXExtraPass"],["class de.fraunhofer.aisec.cpg.passes.ResolveCallExpressionAmbiguityPass"],["class de.fraunhofer.aisec.cpg.passes.EvaluationOrderGraphPass"],["class de.fraunhofer.aisec.cpg.passes.SymbolResolver"],["class de.fraunhofer.aisec.cpg.passes.DFGPass"],["class de.fraunhofer.aisec.cpg.passes.ControlFlowSensitiveDFGPass"],["class de.fraunhofer.aisec.cpg.passes.DynamicInvokeResolver"]],"replacedPasses":{},"softwareComponents":{"application":[".\abstract_hardware_model.cc"]},"symbols":{},"topLevels":{},"useParallelFrontends":false,"useParallelPasses":false,"useUnityBuild":false}
ctx: de.fraunhofer.aisec.cpg.TranslationContext@c96a4ea
dirtyNodes: {Reference[name=fgets,location=abstract_hardware_model.cc(60:10-60:15),type=FunctionType[name=fgets(char[], char[], FILE*)UNKNOWN],refersTo=FunctionDeclaration[name=fgets,location=,parameters=[ParameterDeclaration[name=charPtr0,location=], ParameterDeclaration[name=charPtr1,location=], ParameterDeclaration[name=filePtr2,location=]]]]=[], RecordDeclaration[name=std::nullptr_t,location=,name=std::nullptr_t,kind=struct,superTypeDeclarations=[],fields=[],methods=[],constructors=[],records=[]]=[], Literal[location=abstract_hardware_model.cc(55:17-55:21),type=ObjectType[name=std::nullptr_t],value=]=[], NamespaceDeclaration[name=std,location=]=[], VariableDeclaration[name=fp,location=abstract_hardware_model.cc(47:8-47:18),initializer=Literal[location=abstract_hardware_model.cc(47:14-47:18),type=ObjectType[name=std::nullptr_t],value=]]=[], MethodDeclaration[name=simt_stack::resume,location=abstract_hardware_model.cc(51:1-64:2),parameters=[ParameterDeclaration[name=fname,location=abstract_hardware_model.cc(51:25-51:36)]]]=[], DeclarationStatement[location=abstract_hardware_model.cc(58:3-58:18),declarations=[VariableDeclaration[name=line,location=abstract_hardware_model.cc(58:8-58:17),initializer=]]]=[], Reference[name=assert,location=abstract_hardware_model.cc(55:3-55:9),type=FunctionType[name=assert(UNKNOWN)UNKNOWN],refersTo=FunctionDeclaration[name=assert,location=,parameters=[ParameterDeclaration[name=unknown0,location=]]]]=[], CallExpression[name=assert,location=abstract_hardware_model.cc(55:3-55:23),type=UNKNOWN]=[], CallExpression[name=fclose,location=abstract_hardware_model.cc(62:5-62:17),type=UNKNOWN]=[], CallExpression[name=reset,location=abstract_hardware_model.cc(52:3-52:11),type=UNKNOWN]=[], WhileStatement[location=abstract_hardware_model.cc(60:3-63:4),statement=Block[location=abstract_hardware_model.cc(61:3-63:4),type=UNKNOWN],else=,condition=BinaryOperator[lhs=fgets,rhs=,operatorCode=!=,location=abstract_hardware_model.cc(60:10-60:47)],conditionDeclaration=]=[], VariableDeclaration[name=line,location=abstract_hardware_model.cc(58:8-58:17),initializer=]=[],
Reference[name=reset,location=abstract_hardware_model.cc(52:3-52:8),type=FunctionType[name=reset()UNKNOWN],refersTo=FunctionDeclaration[name=reset,location=,parameters=[]]]=[], DeclarationStatement[location=abstract_hardware_model.cc(47:3-47:18),declarations=[VariableDeclaration[name=fp,location=abstract_hardware_model.cc(47:8-47:18),initializer=Literal[location=abstract_hardware_model.cc(47:14-47:18),type=ObjectType[name=std::nullptr_t],value=]]]]=[], Reference[name=fclose,location=abstract_hardware_model.cc(62:5-62:11),type=FunctionType[name=fclose(FILE*)UNKNOWN],refersTo=FunctionDeclaration[name=fclose,location=,parameters=[ParameterDeclaration[name=filePtr0,location=]]]]=[], AssignExpression[name==,location=abstract_hardware_model.cc(57:3-57:13),type=UNKNOWN]=[], Reference[name=line,location=abstract_hardware_model.cc(60:29-60:33),type=PointerType[name=char[]],refersTo=VariableDeclaration[name=line,location=abstract_hardware_model.cc(58:8-58:17),initializer=]]=[],
AstEdge[end=RecordDeclaration[name=FILE,location=,name=FILE,kind=struct,superTypeDeclarations=[],fields=[],methods=[],constructors=[],records=[]]],
AstEdge[end=NamespaceDeclaration[name=std,location=]], AstEdge[end=FunctionDeclaration[name=reset,location=,parameters=[]]],
AstEdge[end=FunctionDeclaration[name=assert,location=,parameters=[ParameterDeclaration[name=unknown0,location=]]]],
AstEdge[end=FunctionDeclaration[name=fgets,location=,parameters=[ParameterDeclaration[name=charPtr0,location=], ParameterDeclaration[name=charPtr1,location=], ParameterDeclaration[name=filePtr2,location=]]]],
AstEdge[end=FunctionDeclaration[name=fclose,location=,parameters=[ParameterDeclaration[name=filePtr0,location=]]]]]]=[],
BinaryOperator[lhs=fp2,rhs=,operatorCode=!=,location=abstract_hardware_model.cc(55:10-55:21)]=[], BinaryOperator[lhs=fgets,rhs=,operatorCode=!=,location=abstract_hardware_model.cc(60:10-60:47)]=[], ReturnStatement[location=,returnValues=[]]=[], Literal[location=abstract_hardware_model.cc(57:9-57:13),type=ObjectType[name=std::nullptr_t],value=]=[], ReturnStatement[location=,returnValues=[]]=[], UnaryOperator[name=sizeof,location=abstract_hardware_model.cc(60:22-60:33),type=PointerType[name=char[]],operatorCode=sizeof,postfix=false,prefix=true]=[], Block[location=abstract_hardware_model.cc(61:3-63:4),type=UNKNOWN]=[], CallExpression[name=fgets,location=abstract_hardware_model.cc(60:10-60:39),type=UNKNOWN]=[], Literal[location=abstract_hardware_model.cc(60:43-60:47),type=ObjectType[name=std::nullptr_t],value=]=[],
IncludeDeclaration[name=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,location=,name=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,filename=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,includes=[],problems=[]]=[], FunctionDeclaration[name=fopen,location=abstract_hardware_model.cc(46:1-49:2),parameters=[ParameterDeclaration[name=filename,location=abstract_hardware_model.cc(46:13-46:27)], ParameterDeclaration[name=option,location=abstract_hardware_model.cc(46:29-46:41)]]]=[], Literal[location=abstract_hardware_model.cc(47:14-47:18),type=ObjectType[name=std::nullptr_t],value=]=[], Literal[location=abstract_hardware_model.cc(54:28-54:31),type=PointerType[name=char[]],value=r]=[], RecordDeclaration[name=FILE,location=,name=FILE,kind=struct,superTypeDeclarations=[],fields=[],methods=[],constructors=[],records=[]]=[], Reference[name=line,location=abstract_hardware_model.cc(60:16-60:20),type=PointerType[name=char[]],refersTo=VariableDeclaration[name=line,location=abstract_hardware_model.cc(58:8-58:17),initializer=]]=[], Reference[name=fp2,location=abstract_hardware_model.cc(60:35-60:38),type=PointerType[name=FILE*],refersTo=VariableDeclaration[name=fp2,location=abstract_hardware_model.cc(54:8-54:32),initializer=CallExpression[name=fopen,location=abstract_hardware_model.cc(54:15-54:32),type=PointerType[name=FILE*]]]]=[], Reference[name=fp2,location=abstract_hardware_model.cc(62:12-62:15),type=PointerType[name=FILE*],refersTo=VariableDeclaration[name=fp2,location=abstract_hardware_model.cc(54:8-54:32),initializer=CallExpression[name=fopen,location=abstract_hardware_model.cc(54:15-54:32),type=PointerType[name=FILE*]]]]=[]}
finalCtx: de.fraunhofer.aisec.cpg.TranslationContext@c96a4ea
isCancelled: false
language: CPPLanguage[name=CPPLanguage,location=]
scratch: {sourceLocationsToFrontend={abstract_hardware_model.cc=CXXLanguageFrontend}}
translatedFiles: [abstract_hardware_model.cc]
translationManager: (접근 불가 또는 오류 발생)
translationUnits: [TranslationUnitDeclaration[declarations=[
AstEdge[end=FunctionDeclaration[name=fopen,location=abstract_hardware_model.cc(46:1-49:2),parameters=[ParameterDeclaration[name=filename,location=abstract_hardware_model.cc(46:13-46:27)], ParameterDeclaration[name=option,location=abstract_hardware_model.cc(46:29-46:41)]]]],
AstEdge[end=MethodDeclaration[name=simt_stack::resume,location=abstract_hardware_model.cc(51:1-64:2),parameters=[ParameterDeclaration[name=fname,location=abstract_hardware_model.cc(51:25-51:36)]]]], AstEdge[end=IncludeDeclaration[name=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,location=,name=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,filename=C:\Users\njkjh\Work\CpgGradle\abstract_hardware_model.h,includes=[],problems=[]]], AstEdge[end=RecordDeclaration[name=FILE,location=,name=FILE,kind=struct,superTypeDeclarations=[],fields=[],methods=[],constructors=[],records=[]]], AstEdge[end=NamespaceDeclaration[name=std,location=]], AstEdge[end=FunctionDeclaration[name=reset,location=,parameters=[]]], AstEdge[end=FunctionDeclaration[name=assert,location=,parameters=[ParameterDeclaration[name=unknown0,location=]]]], AstEdge[end=FunctionDeclaration[name=fgets,location=,parameters=[ParameterDeclaration[name=charPtr0,location=], ParameterDeclaration[name=charPtr1,location=], ParameterDeclaration[name=filePtr2,location=]]]], AstEdge[end=FunctionDeclaration[name=fclose,location=,parameters=[ParameterDeclaration[name=filePtr0,location=]]]]]]]
usedLanguages: [CPPLanguage[name=CPPLanguage,location=]]
additionalProblems: []
annotationEdges: []
annotations: []
argumentIndex: 0
assumptions: []
astChildren: [Component[name=application,location=]]
astParent: null
benchmarkResults: de.fraunhofer.aisec.cpg.helpers.BenchmarkResults@6c8a68c1
code: null
comment: null
id: 00000000-0000-0000-ffff-ffffce71fefe
isImplicit: false
isInferred: false
legacyId: null
location: null
name:
nextCDG: []
nextCDGEdges: []
nextDFG: []
nextDFGEdges: []
nextEOG: []
nextEOGEdges: []
nextFullDFG: []
nextPDG: []
nextPDGEdges: []
overlayEdges: []
overlays: []
prevCDG: []
prevCDGEdges: []
prevDFG: []
prevDFGEdges: []
prevEOG: []
prevEOGEdges: []
prevFullDFG: []
prevPDG: []
prevPDGEdges: []
scope: null

[konradweiss]

Hello :)

thanks for taking interest in our project. To help you I would need some further information from you:

• As I see you are using the CPG as a Library dependence in another project. What version of the CPG are you using as a dependency?
• How are you printing the CPG? Edges like the DFG and EOG may start lower in the AST hierarchy, depending on the parsed code, so if your printing does not go that deep, that may be the reason.
• Are you able to share the code that you are analyzing? Then I would be able to look into it be running the same version of the CPG over the same code.

Best regards,
Konrad

[konradweiss]

@kimchangsu9487 Did you solve your issue, or does it persist? If you have the time to follow up on my questions above, I would love to investigate the Issue. Otherwise, I will consider closing this discussion.

Best regards,
Konrad