[cfe-commits] r97225 - /cfe/trunk/lib/Checker/GRExprEngine.cpp

[Zhongxing Xu]

Author: zhongxingxu
Date: Fri Feb 26 09:43:34 2010
New Revision: 97225

URL: http://llvm.org/viewvc/llvm-project?rev=97225&view=rev
Log:
Use a GDM to record the returned expression in the state when VisitReturnStmt.
Use this information to find the returned value and bind it to CallExpr in
ProcessCallExit.
And there is no need to remove dead bindings in ProcessCallExit, because
a. it would clean up the return value bound to CallExpr
b. we still would do it in the next ProcessStmt(), where we would not misclean
   up the return value.

Modified:
    cfe/trunk/lib/Checker/GRExprEngine.cpp

Modified: cfe/trunk/lib/Checker/GRExprEngine.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Checker/GRExprEngine.cpp?rev=97225&r1=97224&r2=97225&view=diff
==============================================================================
--- cfe/trunk/lib/Checker/GRExprEngine.cpp (original)
+++ cfe/trunk/lib/Checker/GRExprEngine.cpp Fri Feb 26 09:43:34 2010
@@ -37,6 +37,15 @@
 using llvm::cast;
 using llvm::APSInt;
 
+namespace {
+  // Trait class for recording returned expression in the state.
+  struct ReturnExpr {
+    static int TagInt;
+    typedef const Stmt *data_type;
+  };
+  int ReturnExpr::TagInt; 
+}
+
 //===----------------------------------------------------------------------===//
 // Utility functions.
 //===----------------------------------------------------------------------===//
@@ -1309,16 +1318,15 @@
   const ExplodedNode *Pred = B.getPredecessor();
   const StackFrameContext *LocCtx = 
                             cast<StackFrameContext>(Pred->getLocationContext());
-  const StackFrameContext *ParentSF = 
-                            cast<StackFrameContext>(LocCtx->getParent());
-
-  SymbolReaper SymReaper(*ParentSF->getLiveVariables(), getSymbolManager(),
-                         ParentSF);
   const Stmt *CE = LocCtx->getCallSite();
 
-  state = getStateManager().RemoveDeadBindings(state, const_cast<Stmt*>(CE),
-                                               SymReaper);
-  
+  // If the callee returns an expression, bind its value to CallExpr.
+  const Stmt *ReturnedExpr = state->get<ReturnExpr>();
+  if (ReturnedExpr) {
+    SVal RetVal = state->getSVal(ReturnedExpr);
+    state = state->BindExpr(CE, RetVal);
+  }
+
   B.GenerateNode(state);
 }
 
@@ -2889,10 +2897,20 @@
 
 void GRExprEngine::VisitReturnStmt(ReturnStmt *RS, ExplodedNode *Pred,
                                    ExplodedNodeSet &Dst) {
-
   ExplodedNodeSet Src;
   if (Expr *RetE = RS->getRetValue()) {
-    Visit(RetE, Pred, Src);
+    // Record the returned expression in the state.
+    {
+      static int Tag;
+      SaveAndRestore<const void *> OldTag(Builder->Tag);
+      Builder->Tag = &Tag;
+      const GRState *state = GetState(Pred);
+      state = state->set<ReturnExpr>(RetE);
+      Pred = Builder->generateNode(RetE, state, Pred);
+    }
+    // We may get a NULL Pred because we generated a cached node.
+    if (Pred)
+      Visit(RetE, Pred, Src);
   }
   else {
     Src.Add(Pred);