Added initial support into the flow-sensitive dataflow solver to visit the Block-level expression

in a block's terminator.  This expression is visited within a block, but it is accessed by the
terminator.  This is important to observe because for live-variables analysis the block-level
expression is live between the terminator and where the expression occurs in the block.  So far
this hasn't been an issue to not observe this because the block-level expression used in the
terminator is always the last one in the block, and we have never queried the liveness information
about this point (but before the terminator).

llvm-svn: 49709

1 files changed, 19 insertions, 1 deletions

diff --git a/clang/lib/Analysis/LiveVariables.cpp b/clang/lib/Analysis/LiveVariables.cpp
index b704b2d8267..4cef30cab82 100644
--- a/clang/lib/Analysis/LiveVariables.cpp
+++ b/clang/lib/Analysis/LiveVariables.cpp
@@ -73,7 +73,8 @@ public:
   void VisitAssign(BinaryOperator* B);
   void VisitDeclStmt(DeclStmt* DS);
   void VisitUnaryOperator(UnaryOperator* U);
-  void Visit(Stmt *S);
+  void Visit(Stmt *S);  
+  void VisitTerminator(Stmt* S); 
 };
       
 void TransferFuncs::Visit(Stmt *S) {
@@ -90,6 +91,23 @@ void TransferFuncs::Visit(Stmt *S) {
     // For block-level expressions, mark that they are live.
     LiveState(S,AD) = Alive;
 }
+  
+void TransferFuncs::VisitTerminator(Stmt* S) {
+  return;
+  
+  for (Stmt::child_iterator I = S->child_begin(), E = S->child_end();
+       I != E; ++I) {
+    
+    Stmt* Child = *I;
+    if (!Child) continue;
+    
+    if (getCFG().isBlkExpr(Child)) {
+      LiveState(Child, AD) = Alive;
+      return;  // Only one "condition" expression.
+    }
+  }
+}
+
 
 void TransferFuncs::VisitDeclRefExpr(DeclRefExpr* DR) {
   if (VarDecl* V = dyn_cast<VarDecl>(DR->getDecl()))