[analyzer] Allow TrackConstraintBRVisitor to work when the value it’s tracking is not live in the last node of the path

We always register the visitor on a node in which the value we are tracking is live and constrained. However,
the visitation can restart at a node, later on the path, in which the value is under constrained because
it is no longer live. Previously, we just silently stopped tracking in that case.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179731 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 1 deletions

diff --git a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
index 2e5f207f4b..2e67180bea 100644
--- a/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
+++ b/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitor.h
@@ -134,10 +134,15 @@ class TrackConstraintBRVisitor
   bool IsSatisfied;
   bool IsZeroCheck;
 
+  /// We should start tracking from the last node along the path in which the
+  /// value is constrained.
+  bool IsTrackingTurnedOn;
+
 public:
   TrackConstraintBRVisitor(DefinedSVal constraint, bool assumption)
   : Constraint(constraint), Assumption(assumption), IsSatisfied(false),
-    IsZeroCheck(!Assumption && Constraint.getAs<Loc>()) {}
+    IsZeroCheck(!Assumption && Constraint.getAs<Loc>()),
+    IsTrackingTurnedOn(false) {}
 
   void Profile(llvm::FoldingSetNodeID &ID) const;