Remove ProgramState::getSymVal(). It was being misused by Checkers,

with at least one subtle bug in MacOSXKeyChainAPIChecker where the
calling the method was a substitute for assuming a symbolic value
was null (which is not the case).

We still keep ConstraintManager::getSymVal(), but we use that as
an optimization in SValBuilder and ProgramState::getSVal() to
constant-fold SVals.  This is only if the ConstraintManager can
provide us with that information, which is no longer a requirement.
As part of this, introduce a default implementation of
ConstraintManager::getSymVal() which returns null.

For Checkers, introduce ConstraintManager::isNull(), which queries
the state to see if the symbolic value is constrained to be a null
value.  It does this without assuming it has been implicitly constant
folded.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163428 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 3 deletions

diff --git a/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp b/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
index 5d10575d83..3338c479be 100644
--- a/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -3445,9 +3445,8 @@ ProgramStateRef RetainCountChecker::evalAssume(ProgramStateRef state,
   RefBindings::Factory &RefBFactory = state->get_context<RefBindings>();
 
   for (RefBindings::iterator I = B.begin(), E = B.end(); I != E; ++I) {
-    // Check if the symbol is null (or equal to any constant).
-    // If this is the case, stop tracking the symbol.
-    if (state->getSymVal(I.getKey())) {
+    // Check if the symbol is null stop tracking the symbol.
+    if (state->getConstraintManager().isNull(state, I.getKey()).isTrue()) {
       changed = true;
       B = RefBFactory.remove(B, I.getKey());
     }