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, 5 insertions, 0 deletions

diff --git a/clang/lib/Checker/DereferenceChecker.cpp b/clang/lib/Checker/DereferenceChecker.cpp
index af929a7af72..f1d77204cbc 100644
--- a/clang/lib/Checker/DereferenceChecker.cpp
+++ b/clang/lib/Checker/DereferenceChecker.cpp
@@ -125,6 +125,11 @@ void DereferenceChecker::VisitLocation(CheckerContext &C, const Stmt *S,
 
       llvm::SmallString<100> buf;
       llvm::SmallVector<SourceRange, 2> Ranges;
+      
+      // Walk through lvalue casts to get the original expression
+      // that syntactically caused the load.
+      if (const Expr *expr = dyn_cast<Expr>(S))
+        S = expr->IgnoreParenLValueCasts();
 
       switch (S->getStmtClass()) {
         case Stmt::ArraySubscriptExprClass: {