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.

llvm-svn: 163428

1 files changed, 3 insertions, 5 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
index 78554c4e891..ed8e1dc9ec1 100644
--- a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
@@ -22,10 +22,6 @@
 using namespace clang;
 using namespace ento;
 
-// Give the vtable for ConstraintManager somewhere to live.
-// FIXME: Move this elsewhere.
-ConstraintManager::~ConstraintManager() {}
-
 namespace clang { namespace  ento {
 /// Increments the number of times this state is referenced.
 
@@ -238,7 +234,9 @@ SVal ProgramState::getSVal(Loc location, QualType T) const {
   // about).
   if (!T.isNull()) {
     if (SymbolRef sym = V.getAsSymbol()) {
-      if (const llvm::APSInt *Int = getSymVal(sym)) {
+      if (const llvm::APSInt *Int = getStateManager()
+                                    .getConstraintManager()
+                                    .getSymVal(this, sym)) {
         // FIXME: Because we don't correctly model (yet) sign-extension
         // and truncation of symbolic values, we need to convert
         // the integer value to the correct signedness and bitwidth.