Index: cfe/trunk/lib/StaticAnalyzer/Core/Environment.cpp
===================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/Environment.cpp
+++ cfe/trunk/lib/StaticAnalyzer/Core/Environment.cpp
@@ -108,6 +108,7 @@
   case Stmt::ObjCStringLiteralClass:
   case Stmt::StringLiteralClass:
   case Stmt::TypeTraitExprClass:
+  case Stmt::SizeOfPackExprClass:
     // Known constants; defer to SValBuilder.
     return svalBuilder.getConstantVal(cast<Expr>(S)).getValue();
 
Index: cfe/trunk/test/Analysis/sizeofpack.cpp
===================================================================
--- cfe/trunk/test/Analysis/sizeofpack.cpp
+++ cfe/trunk/test/Analysis/sizeofpack.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection \
+// RUN:                    -verify %s
+
+typedef __typeof(sizeof(int)) size_t;
+
+void clang_analyzer_eval(bool);
+
+template <int... N> size_t foo() {
+  return sizeof...(N);
+}
+
+void bar() {
+  clang_analyzer_eval(foo<>() == 0); // expected-warning{{TRUE}}
+  clang_analyzer_eval(foo<1, 2, 3>() == 3); // expected-warning{{TRUE}}
+}