2 files changed, 34 insertions, 57 deletions

diff --git a/lib/Analysis/CallGraph.cpp b/lib/Analysis/CallGraph.cpp
index 424e5c795e..4082e2dc0e 100644
--- a/lib/Analysis/CallGraph.cpp
+++ b/lib/Analysis/CallGraph.cpp
@@ -16,6 +16,7 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/StmtVisitor.h"
+#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/GraphWriter.h"
 
@@ -141,14 +142,8 @@ bool CallGraph::includeInGraph(const Decl *D) {
 void CallGraph::addNodeForDecl(Decl* D, bool IsGlobal) {
   assert(D);
 
-  // Do nothing if the node already exists.
-  if (FunctionMap.find(D) != FunctionMap.end())
-    return;
-
   // Allocate a new node, mark it as root, and process it's calls.
   CallGraphNode *Node = getOrInsertNode(D);
-  if (IsGlobal)
-    Root->addCallee(Node, this);
 
   // Process all the calls by this function as well.
   CGBuilder builder(this, Node);
@@ -168,23 +163,31 @@ CallGraphNode *CallGraph::getOrInsertNode(Decl *F) {
     return Node;
 
   Node = new CallGraphNode(F);
-  // If not root, add to the parentless list.
+  // Make Root node a parent of all functions to make sure all are reachable.
   if (F != 0)
-    ParentlessNodes.insert(Node);
+    Root->addCallee(Node, this);
   return Node;
 }
 
 void CallGraph::print(raw_ostream &OS) const {
   OS << " --- Call graph Dump --- \n";
-  for (const_iterator I = begin(), E = end(); I != E; ++I) {
+
+  // We are going to print the graph in reverse post order, partially, to make
+  // sure the output is deterministic.
+  llvm::ReversePostOrderTraversal<const clang::CallGraph*> RPOT(this);
+  for (llvm::ReversePostOrderTraversal<const clang::CallGraph*>::rpo_iterator
+         I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
+    const CallGraphNode *N = *I;
+
     OS << "  Function: ";
-    if (I->second == Root)
+    if (N == Root)
       OS << "< root >";
     else
-      I->second->print(OS);
+      N->print(OS);
+
     OS << " calls: ";
-    for (CallGraphNode::iterator CI = I->second->begin(),
-        CE = I->second->end(); CI != CE; ++CI) {
+    for (CallGraphNode::const_iterator CI = N->begin(),
+                                       CE = N->end(); CI != CE; ++CI) {
       assert(*CI != Root && "No one can call the root node.");
       (*CI)->print(OS);
       OS << " ";
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.