Analyzer: Teach analyzer how to handle TypeTraitExpr

Summary:
`TypeTraitExpr`s are not supported by the ExprEngine today. Analyzer
creates a sink, and aborts the block. Therefore, certain bugs that
involve type traits intrinsics cannot be detected (see PR24710).

This patch creates boolean `SVal`s for `TypeTraitExpr`s, which are
evaluated by the compiler.

Test within the patch is a summary of PR24710.

Reviewers: zaks.anna, dcoughlin, krememek

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D12482

llvm-svn: 248314

1 files changed, 2 insertions, 2 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index 00d9c7a9616..0865189193d 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -756,7 +756,6 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::MSPropertyRefExprClass:
     case Stmt::CXXUnresolvedConstructExprClass:
     case Stmt::DependentScopeDeclRefExprClass:
-    case Stmt::TypeTraitExprClass:
     case Stmt::ArrayTypeTraitExprClass:
     case Stmt::ExpressionTraitExprClass:
     case Stmt::UnresolvedLookupExprClass:
@@ -902,7 +901,8 @@ void ExprEngine::Visit(const Stmt *S, ExplodedNode *Pred,
     case Stmt::CXXPseudoDestructorExprClass:
     case Stmt::SubstNonTypeTemplateParmExprClass:
     case Stmt::CXXNullPtrLiteralExprClass:
-    case Stmt::OMPArraySectionExprClass: {
+    case Stmt::OMPArraySectionExprClass:
+    case Stmt::TypeTraitExprClass: {
       Bldr.takeNodes(Pred);
       ExplodedNodeSet preVisit;
       getCheckerManager().runCheckersForPreStmt(preVisit, Pred, S, *this);