Added a new ProgramPoint: PostPurgeDeadSymbols. This new program point distinguishes between the cases when we just evaluated the transfer function of a Stmt* (PostStmt) or performed a load (PostLoad). This solves a caching bug observed in a recent bug report.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52443 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 2 deletions

diff --git a/lib/Analysis/GRExprEngine.cpp b/lib/Analysis/GRExprEngine.cpp
index 837d910091..2580172d53 100644
--- a/lib/Analysis/GRExprEngine.cpp
+++ b/lib/Analysis/GRExprEngine.cpp
@@ -214,6 +214,9 @@ void GRExprEngine::ProcessStmt(Stmt* S, StmtNodeBuilder& builder) {
     SaveAndRestore<bool> OldSink(Builder->BuildSinks);
     SaveOr OldHasGen(Builder->HasGeneratedNode);
 
+    SaveAndRestore<bool> OldPurgeDeadSymbols(Builder->PurgingDeadSymbols);
+    Builder->PurgingDeadSymbols = true;
+    
     TF->EvalDeadSymbols(Tmp, *this, *Builder, EntryNode, S, 
                         CleanedState, DeadSymbols);
 
@@ -965,7 +968,10 @@ ValueState* GRExprEngine::EvalLocation(Expr* Ex, NodeTy* Pred,
   
   // Check for loads/stores from/to undefined values.  
   if (location.isUndef()) {
-    if (NodeTy* Succ = Builder->generateNode(Ex, St, Pred, isLoad)) {
+    ProgramPoint::Kind K =
+      isLoad ? ProgramPoint::PostLoadKind : ProgramPoint::PostStmtKind;
+    
+    if (NodeTy* Succ = Builder->generateNode(Ex, St, Pred, K)) {
       Succ->markAsSink();
       UndefDeref.insert(Succ);
     }
@@ -1000,7 +1006,10 @@ ValueState* GRExprEngine::EvalLocation(Expr* Ex, NodeTy* Pred,
     // We don't use "MakeNode" here because the node will be a sink
     // and we have no intention of processing it later.
     
-    NodeTy* NullNode = Builder->generateNode(Ex, StNull, Pred, isLoad);
+    ProgramPoint::Kind K =
+      isLoad ? ProgramPoint::PostLoadKind : ProgramPoint::PostStmtKind;
+
+    NodeTy* NullNode = Builder->generateNode(Ex, StNull, Pred, K);
     
     if (NullNode) {
       
@@ -2437,6 +2446,7 @@ struct VISIBILITY_HIDDEN DOTGraphTraits<GRExprEngine::NodeTy*> :
         break;
         
       case ProgramPoint::PostLoadKind:
+      case ProgramPoint::PostPurgeDeadSymbolsKind:
       case ProgramPoint::PostStmtKind: {
         const PostStmt& L = cast<PostStmt>(Loc);        
         Stmt* S = L.getStmt();