1 files changed, 18 insertions, 44 deletions

diff --git a/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp b/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
index 025891adf8..07aa5b074a 100644
--- a/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
+++ b/lib/StaticAnalyzer/Frontend/AnalysisConsumer.cpp
@@ -39,6 +39,7 @@
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Timer.h"
@@ -417,61 +418,34 @@ AnalysisConsumer::getInliningModeForFunction(const Decl *D,
 }
 
 void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
-  // Otherwise, use the Callgraph to derive the order.
-  // Build the Call Graph.
-  CallGraph CG;
-
-  // Add all the top level declarations to the graph.
+  // Build the Call Graph by adding all the top level declarations to the graph.
   // Note: CallGraph can trigger deserialization of more items from a pch
   // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
   // We rely on random access to add the initially processed Decls to CG.
+  CallGraph CG;
   for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
     CG.addToCallGraph(LocalTUDecls[i]);
   }
 
-  // Find the top level nodes - children of root + the unreachable (parentless)
-  // nodes.
-  llvm::SmallVector<CallGraphNode*, 24> TopLevelFunctions;
-  for (CallGraph::nodes_iterator TI = CG.parentless_begin(),
-                                 TE = CG.parentless_end(); TI != TE; ++TI) {
-    TopLevelFunctions.push_back(*TI);
-    NumFunctionTopLevel++;
-  }
-  CallGraphNode *Entry = CG.getRoot();
-  for (CallGraphNode::iterator I = Entry->begin(),
-                               E = Entry->end(); I != E; ++I) {
-    TopLevelFunctions.push_back(*I);
-    NumFunctionTopLevel++;
-  }
-
-  // Make sure the nodes are sorted in order reverse of their definition in the 
-  // translation unit. This step is very important for performance. It ensures 
-  // that we analyze the root functions before the externally available 
-  // subroutines.
-  std::deque<CallGraphNode*> BFSQueue;
-  for (llvm::SmallVector<CallGraphNode*, 24>::reverse_iterator
-         TI = TopLevelFunctions.rbegin(), TE = TopLevelFunctions.rend();
-         TI != TE; ++TI)
-    BFSQueue.push_back(*TI);
-
-  // BFS over all of the functions, while skipping the ones inlined into
-  // the previously processed functions. Use external Visited set, which is
-  // also modified when we inline a function.
+  // Walk over all of the call graph nodes in topological order, so that we
+  // analyze parents before the children. Skip the functions inlined into
+  // the previously processed functions. Use external Visited set to identify
+  // inlined functions. The topological order allows the "do not reanalyze
+  // previously inlined function" performance heuristic to be triggered more
+  // often.
   SetOfConstDecls Visited;
   SetOfConstDecls VisitedAsTopLevel;
-  while(!BFSQueue.empty()) {
-    CallGraphNode *N = BFSQueue.front();
-    BFSQueue.pop_front();
-
-    // Push the children into the queue.
-    for (CallGraphNode::const_iterator CI = N->begin(),
-         CE = N->end(); CI != CE; ++CI) {
-      if (!shouldSkipFunction((*CI)->getDecl(), Visited, VisitedAsTopLevel))
-        BFSQueue.push_back(*CI);
-    }
+  llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
+  for (llvm::ReversePostOrderTraversal<clang::CallGraph*>::rpo_iterator
+         I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
+    NumFunctionTopLevel++;
 
+    CallGraphNode *N = *I;
     Decl *D = N->getDecl();
-    assert(D);
+    
+    // Skip the abstract root node.
+    if (!D)
+      continue;
 
     // Skip the functions which have been processed already or previously
     // inlined.