[analyzer] Skip printing duplicate nodes, even if nodes have multiple predecessors/successors

Still generate a node, but leave the redundant field empty.

Differential Revision: https://reviews.llvm.org/D51821

llvm-svn: 342308

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 638fc5de10f..a1fcd121311 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -3177,7 +3177,12 @@ struct DOTGraphTraits<ExplodedNode*> : public DefaultDOTGraphTraits {
         << ")"
         << " NodeID: " << N->getID(&Graph) << " (" << (const void *)N << ")\\|";
 
-    State->printDOT(Out, N->getLocationContext());
+    bool SameAsAllPredecessors =
+        std::all_of(N->pred_begin(), N->pred_end(), [&](const ExplodedNode *P) {
+          return P->getState() == State;
+        });
+    if (!SameAsAllPredecessors)
+      State->printDOT(Out, N->getLocationContext());
     return Out.str();
   }
 };