Merge pull request #417 from secure-software-engineering/f-InterproceduralFFEnhancements

Bug fixes and enhancements in interprocedural flow functions

Author: pdschubert

include/phasar/PhasarLLVM/DataFlowSolver/IfdsIde/LLVMFlowFunctions.h

@@ -180,12 +180,14 @@ class MapFactsToCallee : public FlowFunction<const llvm::Value *, Container> {
       }
       return {};
     }
+    container_type Res;
     // Pass global variables as is, if desired
+    // Globals could also be actual arguments, then the formal argument needs to
+    // be generated below.
     // Need llvm::Constant here to cover also ConstantExpr and ConstantAggregate
     if (PropagateGlobals && llvm::isa<llvm::Constant>(Source)) {
-      return {Source};
+      Res.insert(Source);
     }
-    container_type Res;
     // Handle back propagation of return value in backwards analysis.
     // We add it to the result here. Later, normal flow in callee can identify
     // it
@@ -259,6 +261,7 @@ class MapFactsToCaller : public FlowFunction<const llvm::Value *, Container> {
   const llvm::Function *CalleeFun;
   const llvm::ReturnInst *ExitInst;
   bool PropagateGlobals;
+  const bool PropagateZeroToCaller;
   std::vector<const llvm::Value *> Actuals;
   std::vector<const llvm::Value *> Formals;
   std::function<bool(const llvm::Value *)> ParamPredicate;
@@ -271,10 +274,12 @@ class MapFactsToCaller : public FlowFunction<const llvm::Value *, Container> {
       std::function<bool(const llvm::Value *)> ParamPredicate =
           [](const llvm::Value *) { return true; },
       std::function<bool(const llvm::Function *)> ReturnPredicate =
-          [](const llvm::Function *) { return true; })
+          [](const llvm::Function *) { return true; },
+      bool PropagateZeroToCaller = true)
       : CallSite(CallSite), CalleeFun(CalleeFun),
         ExitInst(llvm::dyn_cast<llvm::ReturnInst>(ExitInst)),
         PropagateGlobals(PropagateGlobals),
+        PropagateZeroToCaller(PropagateZeroToCaller),
         ParamPredicate(std::move(ParamPredicate)),
         ReturnPredicate(std::move(ReturnPredicate)) {
     assert(ExitInst && "Should not be null");
@@ -294,12 +299,16 @@ class MapFactsToCaller : public FlowFunction<const llvm::Value *, Container> {
   container_type computeTargets(const llvm::Value *Source) override {
     assert(!CalleeFun->isDeclaration() &&
            "Cannot perform mapping to caller for function declaration");
-    // Pass ZeroValue as is
+    // Pass ZeroValue as is, if desired
     if (LLVMZeroValue::getInstance()->isLLVMZeroValue(Source)) {
-      return {Source};
+      if (PropagateZeroToCaller) {
+        return {Source};
+      }
+      return {};
     }
     // Pass global variables as is, if desired
-    if (PropagateGlobals && llvm::isa<llvm::GlobalVariable>(Source)) {
+    // Need llvm::Constant here to cover also ConstantExpr and ConstantAggregate
+    if (PropagateGlobals && llvm::isa<llvm::Constant>(Source)) {
       return {Source};
     }
     // Do the parameter mapping
@@ -340,7 +349,8 @@ class MapFactsToCaller : public FlowFunction<const llvm::Value *, Container> {
       }
     }
     // Collect return value facts
-    if (Source == ExitInst->getReturnValue() && ReturnPredicate(CalleeFun)) {
+    if (ExitInst != nullptr && Source == ExitInst->getReturnValue() &&
+        ReturnPredicate(CalleeFun)) {
       Res.insert(CallSite);
     }
     return Res;