[analyzer] Fix a rare crash for valist check.

It looks like on some host-triples the result of a valist related expr can be
a LazyCompoundVal. Handle that case in the check.

Patch by Abramo Bagnara!

llvm-svn: 297619

1 files changed, 2 insertions, 6 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/ValistChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ValistChecker.cpp
index 9515c67a4d2..d12ba625807 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ValistChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ValistChecker.cpp
@@ -165,11 +165,8 @@ void ValistChecker::checkPreCall(const CallEvent &Call,
 const MemRegion *ValistChecker::getVAListAsRegion(SVal SV, const Expr *E,
                                                   bool &IsSymbolic,
                                                   CheckerContext &C) const {
-  // FIXME: on some platforms CallAndMessage checker finds some instances of
-  // the uninitialized va_list usages. CallAndMessage checker is disabled in
-  // the tests so they can verify platform independently those issues. As a
-  // side effect, this check is required here.
-  if (SV.isUnknownOrUndef())
+  const MemRegion *Reg = SV.getAsRegion();
+  if (!Reg)
     return nullptr;
   // TODO: In the future this should be abstracted away by the analyzer.
   bool VaListModelledAsArray = false;
@@ -178,7 +175,6 @@ const MemRegion *ValistChecker::getVAListAsRegion(SVal SV, const Expr *E,
     VaListModelledAsArray =
         Ty->isPointerType() && Ty->getPointeeType()->isRecordType();
   }
-  const MemRegion *Reg = SV.getAsRegion();
   if (const auto *DeclReg = Reg->getAs<DeclRegion>()) {
     if (isa<ParmVarDecl>(DeclReg->getDecl()))
       Reg = C.getState()->getSVal(SV.castAs<Loc>()).getAsRegion();