From: Ted Kremenek <kremenek@apple.com>
Date: Fri, 14 Nov 2008 21:07:14 +0000 (+0000)
Subject: Minor tweaks to liveness analysis:
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=06529aeadf03c2a2231a4c7221c422e3650a2a71;p=clang

Minor tweaks to liveness analysis:
- Block-expression for 'ObjCForCollectionStmt' is not alive before it occurs
- Recursively visit 'element' expression for ObjCForCollectionStmt to get liveness for referenced block-level expressions and variables.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59316 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/LiveVariables.cpp b/lib/Analysis/LiveVariables.cpp
index 7b04beb2b5..4b181a954c 100644
--- a/lib/Analysis/LiveVariables.cpp
+++ b/lib/Analysis/LiveVariables.cpp
@@ -179,6 +179,9 @@ void TransferFuncs::VisitBinaryOperator(BinaryOperator* B) {
 void
 TransferFuncs::BlockStmt_VisitObjCForCollectionStmt(ObjCForCollectionStmt* S) {
   
+  // This is a block-level expression.  Its value is 'dead' before this point.
+  LiveState(S, AD) = Dead;
+
   // This represents a 'use' of the collection.
   Visit(S->getCollection());
   
@@ -193,6 +196,10 @@ TransferFuncs::BlockStmt_VisitObjCForCollectionStmt(ObjCForCollectionStmt* S) {
     Expr* ElemExpr = cast<Expr>(Element)->IgnoreParens();    
     if ((DR = dyn_cast<DeclRefExpr>(ElemExpr)))
       VD = cast<VarDecl>(DR->getDecl());
+    else {
+      Visit(ElemExpr);
+      return;
+    }
   }
 
   if (VD) {