[analyzer] Add a test that we are, in fact, doing a DFS on the ExplodedGraph.

Previously:
...the comment said DFS...
...the WorkList being instantiated said BFS...
...and the implementation was actually DFS...
...due to an unintentional change in 2010...
...and everything kept working anyway.

This fixes our std::deque implementation of BFS, but switches back to a
SmallVector-based implementation of DFS.

We should probably still investigate the ramifications of DFS vs. BFS,
especially for large functions (and especially when we hit our block path
limit), since this might completely change our memory use. It can also mask
some bugs and reveal others depending on when we halt analysis. But at least
we will not have this kind of little mistake creep in again.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159397 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 9 deletions

diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h b/include/clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h
index 5bd566ff63..e75cdd8759 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h
@@ -65,7 +65,7 @@ private:
   /// WList - A set of queued nodes that need to be processed by the
   ///  worklist algorithm.  It is up to the implementation of WList to decide
   ///  the order that nodes are processed.
-  WorkList* WList;
+  OwningPtr<WorkList> WList;
 
   /// BCounterFactory - A factory object for created BlockCounter objects.
   ///   These are used to record for key nodes in the ExplodedGraph the
@@ -107,20 +107,15 @@ private:
   ExplodedNode *generateCallExitBeginNode(ExplodedNode *N);
 
 public:
-  /// Construct a CoreEngine object to analyze the provided CFG using
-  ///  a DFS exploration of the exploded graph.
+  /// Construct a CoreEngine object to analyze the provided CFG.
   CoreEngine(SubEngine& subengine, SetOfConstDecls *VisitedCallees,
              FunctionSummariesTy *FS)
     : SubEng(subengine), G(new ExplodedGraph()),
-      WList(WorkList::makeBFS()),
+      WList(WorkList::makeDFS()),
       BCounterFactory(G->getAllocator()),
       AnalyzedCallees(VisitedCallees),
       FunctionSummaries(FS){}
 
-  ~CoreEngine() {
-    delete WList;
-  }
-
   /// getGraph - Returns the exploded graph.
   ExplodedGraph& getGraph() { return *G.get(); }
 
@@ -156,7 +151,7 @@ public:
     blocksAborted.push_back(std::make_pair(block, node));
   }
   
-  WorkList *getWorkList() const { return WList; }
+  WorkList *getWorkList() const { return WList.get(); }
 
   BlocksExhausted::const_iterator blocks_exhausted_begin() const {
     return blocksExhausted.begin();