[cxx2a] P1236R1: the validity of a left shift does not depend on the

value of the LHS operand.

llvm-svn: 364265

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp b/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp
index 9ae30b605a0..7cd48bf4437 100644
--- a/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BasicValueFactory.cpp
@@ -231,9 +231,6 @@ BasicValueFactory::evalAPSInt(BinaryOperator::Opcode Op,
       // FIXME: This logic should probably go higher up, where we can
       // test these conditions symbolically.
 
-      if (V1.isSigned() && V1.isNegative())
-        return nullptr;
-
       if (V2.isSigned() && V2.isNegative())
         return nullptr;
 
@@ -242,8 +239,13 @@ BasicValueFactory::evalAPSInt(BinaryOperator::Opcode Op,
       if (Amt >= V1.getBitWidth())
         return nullptr;
 
-      if (V1.isSigned() && Amt > V1.countLeadingZeros())
+      if (!Ctx.getLangOpts().CPlusPlus2a) {
+        if (V1.isSigned() && V1.isNegative())
+          return nullptr;
+
+        if (V1.isSigned() && Amt > V1.countLeadingZeros())
           return nullptr;
+      }
 
       return &getValue( V1.operator<<( (unsigned) Amt ));
     }