Start migration of static analyzer to using the

implicit lvalue-to-rvalue casts that John McCall
recently introduced.  This causes a whole bunch
of logic in the analyzer for handling lvalues
to vanish.  It does, however, raise a few issues
in the analyzer w.r.t to modeling various constructs
(e.g., field accesses to compound literals).

The .c/.m analysis test cases that fail are
due to a missing lvalue-to-rvalue cast that
will get introduced into the AST.  The .cpp
failures were more than I could investigate in
one go, and the patch was already getting huge.
I have XFAILED some of these tests, and they
should obviously be further investigated.

Some highlights of this patch include:

- CFG no longer requires an lvalue bit for
  CFGElements
- StackFrameContext doesn't need an 'asLValue'
  flag
- The "VisitLValue" path from GRExprEngine has
  been eliminated.

Besides the test case failures (XFAILed), there
are surely other bugs that are fallout from
this change.

llvm-svn: 121960

1 files changed, 3 insertions, 2 deletions

diff --git a/clang/lib/Checker/BugReporterVisitors.cpp b/clang/lib/Checker/BugReporterVisitors.cpp
index d466abe0684..20e1296997f 100644
--- a/clang/lib/Checker/BugReporterVisitors.cpp
+++ b/clang/lib/Checker/BugReporterVisitors.cpp
@@ -318,13 +318,14 @@ void clang::bugreporter::registerTrackNullOrUndefValue(BugReporterContext& BRC,
   GRStateManager &StateMgr = BRC.getStateManager();
   const GRState *state = N->getState();
 
+  // Walk through lvalue-to-rvalue conversions.  
   if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(S)) {
     if (const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl())) {
       const VarRegion *R =
-      StateMgr.getRegionManager().getVarRegion(VD, N->getLocationContext());
+        StateMgr.getRegionManager().getVarRegion(VD, N->getLocationContext());
 
       // What did we load?
-      SVal V = state->getSVal(S);
+      SVal V = state->getSVal(loc::MemRegionVal(R));
 
       if (isa<loc::ConcreteInt>(V) || isa<nonloc::ConcreteInt>(V)
           || V.isUndef()) {