When processing the transfer function for a statement, evaluate

RemoveDeadBindings early because (1) it will always be called and (2) we can
dispatch to a plug-in transfer function that can evaluate the effect of dead
symbols (not yet added).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@48114 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 16 insertions, 17 deletions

diff --git a/Analysis/GRExprEngine.cpp b/Analysis/GRExprEngine.cpp
index e8d0306e21..932372c3a3 100644
--- a/Analysis/GRExprEngine.cpp
+++ b/Analysis/GRExprEngine.cpp
@@ -39,16 +39,6 @@ using llvm::dyn_cast;
 using llvm::cast;
 using llvm::APSInt;
 
-ValueState* GRExprEngine::RemoveDeadBindings(ValueState* St) {
-  
-  if (StateCleaned || !CurrentStmt)
-    return St;
-  
-  StateCleaned = true;
-  
-  return StateMgr.RemoveDeadBindings(St, CurrentStmt, Liveness);
-}
-
 
 ValueState* GRExprEngine::getInitialState() {
 
@@ -420,7 +410,13 @@ void GRExprEngine::ProcessStmt(Stmt* S, StmtNodeBuilder& builder) {
   StmtEntryNode = builder.getLastNode();
   CurrentStmt = S;
   NodeSet Dst;
-  StateCleaned = false;
+  
+  // Create the cleaned state.
+
+  RDBInState = StmtEntryNode->getState();
+  RDBOutState = StateMgr.RemoveDeadBindings(RDBInState, CurrentStmt, Liveness);
+
+  // Visit the statement.
 
   Visit(S, StmtEntryNode, Dst);
 
@@ -428,10 +424,7 @@ void GRExprEngine::ProcessStmt(Stmt* S, StmtNodeBuilder& builder) {
   // dead mappings removed.
   
   if (Dst.size() == 1 && *Dst.begin() == StmtEntryNode) {
-    ValueState* St =
-      StateCleaned ? StmtEntryNode->getState() : 
-                     RemoveDeadBindings(StmtEntryNode->getState());
-    
+    ValueState* St = RemoveDeadBindings(StmtEntryNode->getState());
     builder.generateNode(S, St, StmtEntryNode);
   }
   
@@ -440,6 +433,8 @@ void GRExprEngine::ProcessStmt(Stmt* S, StmtNodeBuilder& builder) {
   CurrentStmt = NULL;
   StmtEntryNode = NULL;
   Builder = NULL;
+  RDBInState = NULL;
+  RDBOutState = NULL;
 }
 
 void GRExprEngine::VisitDeclRefExpr(DeclRefExpr* D, NodeTy* Pred, NodeSet& Dst){
diff --git a/include/clang/Analysis/PathSensitive/GRExprEngine.h b/include/clang/Analysis/PathSensitive/GRExprEngine.h
index 7b1115bee8..74ad499ab7 100644
--- a/include/clang/Analysis/PathSensitive/GRExprEngine.h
+++ b/include/clang/Analysis/PathSensitive/GRExprEngine.h
@@ -120,7 +120,8 @@ protected:
   ///   where a pass-by-value argument has an undefined value.
   UndefArgsTy UndefArgs;
   
-  bool StateCleaned;
+  ValueState* RDBInState;
+  ValueState* RDBOutState;
   
 public:
   GRExprEngine(GraphTy& g) : 
@@ -265,7 +266,10 @@ protected:
   ///  that all subexpression mappings are removed and that any
   ///  block-level expressions that are not live at 'CurrentStmt' also have 
   ///  their mappings removed.
-  ValueState* RemoveDeadBindings(ValueState* St);
+  ValueState* RemoveDeadBindings(ValueState* St) {
+    assert (St);
+    return St == RDBInState ? RDBOutState : St;
+  }
   
   ValueState* SetRVal(ValueState* St, Expr* Ex, RVal V);