[analyzer] Highlight nodes which have error reports in them in red in exploded graph

[george.karpenkov]

Summary

Add "blue" to the outline of nodes which have sinks.

Presenting the legend remains to be figured out.

[NoQ]

I still think we need to add some text as well, not just color.

[george.karpenkov]

@NoQ done

[NoQ]

Yay!

[Szelethus]

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

2957

Nit: missing space: static_cast<ExprEngine *>

[george.karpenkov]

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

2957

OK! Maybe I should just run clang-format automagically

clang/lib/StaticAnalyzer/Core/ExprEngine.cpp

 
 #ifndef NDEBUG
 namespace llvm {
 
 template<>
 struct DOTGraphTraits<ExplodedGraph*> : public DefaultDOTGraphTraits {
   DOTGraphTraits (bool isSimple = false) : DefaultDOTGraphTraits(isSimple) {}
 
-  // FIXME: Since we do not cache error nodes in ExprEngine now, this does not
-  // work.
-  static std::string getNodeAttributes(const ExplodedNode *N,
-                                       ExplodedGraph *G) {
-    if (N->isSink())
-      return "color=red";
-    return {};
-  }
+  static bool nodeHasBugReport(const ExplodedNode *N) {
+    BugReporter &BR = static_cast<ExprEngine*>(
+      N->getState()->getStateManager().getOwningEngine())->getBugReporter();
 
-  static bool isNodeHidden(const ExplodedNode *N) {
-    return N->isTrivial();
-  }
+    const auto EQClasses =
+        llvm::make_range(BR.EQClasses_begin(), BR.EQClasses_end());
 
-  static std::string getNodeLabel(const ExplodedNode *N, ExplodedGraph *G){
-    std::string sbuf;
-    llvm::raw_string_ostream Out(sbuf);
+    for (const auto &EQ : EQClasses) {
+      for (const BugReport &Report : EQ) {
+        if (Report.getErrorNode() == N)
+          return true;
+      }
+    }
+    return false;
+  }
 
-    // Find the first node which program point and tag has to be included in
-    // the output.
+  /// \p PreCallback: callback before break.
+  /// \p PostCallback: callback after break.
+  /// \p Stop: stop iteration if returns {@code true}
+  /// \return Whether {@code Stop} ever returned {@code true}.
+  static bool traverseHiddenNodes(
+      const ExplodedNode *N,
+      llvm::function_ref<void(const ExplodedNode *)> PreCallback,
+      llvm::function_ref<void(const ExplodedNode *)> PostCallback,
+      llvm::function_ref<bool(const ExplodedNode *)> Stop) {
     const ExplodedNode *FirstHiddenNode = N;
     while (FirstHiddenNode->pred_size() == 1 &&
            isNodeHidden(*FirstHiddenNode->pred_begin())) {
       FirstHiddenNode = *FirstHiddenNode->pred_begin();
     }
-
-    ProgramStateRef State = N->getState();
-
-    // Dump program point for all the previously skipped nodes.
     const ExplodedNode *OtherNode = FirstHiddenNode;
     while (true) {
-      OtherNode->getLocation().print(/*CR=*/"\\l", Out);
-
-      if (const ProgramPointTag *Tag = OtherNode->getLocation().getTag())
-        Out << "\\lTag:" << Tag->getTagDescription();
+      if (Stop(OtherNode))
+        return true;
 
       if (OtherNode == N)
         break;
 
       OtherNode = *OtherNode->succ_begin();
+    }
+    return false;
+  }
 
-      Out << "\\l--------\\l";
+  static std::string getNodeAttributes(const ExplodedNode *N,
+                                       ExplodedGraph *G) {
+    SmallVector<StringRef, 10> Out;
+    auto Noop = [](const ExplodedNode*){};
+    if (traverseHiddenNodes(N, Noop, Noop, &nodeHasBugReport)) {
+      Out.push_back("style=filled");
+      Out.push_back("fillcolor=red");
     }
 
+    if (traverseHiddenNodes(N, Noop, Noop,
+                            [](const ExplodedNode *C) { return C->isSink(); }))
+      Out.push_back("color=blue");
+    return llvm::join(Out, ",");
+  }
+
+  static bool isNodeHidden(const ExplodedNode *N) {
+    return N->isTrivial();
+  }
+
+  static std::string getNodeLabel(const ExplodedNode *N, ExplodedGraph *G){
+    std::string sbuf;
+    llvm::raw_string_ostream Out(sbuf);
+
+    ProgramStateRef State = N->getState();
+
+    // Dump program point for all the previously skipped nodes.
+    traverseHiddenNodes(
+        N,
+        [&](const ExplodedNode *OtherNode) {
+          OtherNode->getLocation().print(/*CR=*/"\\l", Out);
+          if (const ProgramPointTag *Tag = OtherNode->getLocation().getTag())
+            Out << "\\lTag:" << Tag->getTagDescription();
+          if (N->isSink())
+            Out << "\\lNode is sink\\l";
+          if (nodeHasBugReport(N))
+            Out << "\\lBug report attached\\l";
+        },
+        [&](const ExplodedNode *OtherNode) { Out << "\\l--------\\l"; },
+        [&](const ExplodedNode *N) { return false; });
+
     Out << "\\l\\|";
 
     Out << "StateID: ST" << State->getID() << ", NodeID: N" << N->getID(G)
         << " <" << (const void *)N << ">\\|";
 
     bool SameAsAllPredecessors =
         std::all_of(N->pred_begin(), N->pred_end(), [&](const ExplodedNode *P) {
           return P->getState() == State;