sandbox: Avoid ~(flag1 | flag2 | ...) expressions

sandbox/linux/bpf_dsl/bpf_dsl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SANDBOX_LINUX_BPF_DSL_BPF_DSL_H_
 #define SANDBOX_LINUX_BPF_DSL_BPF_DSL_H_
 
 #include <stdint.h>
 
 #include <utility>
@@ skipping 25 matching lines @@
 //      using namespace sandbox::bpf_dsl;
 //
 //      class SillyPolicy : public SandboxBPFDSLPolicy {
 //       public:
 //        SillyPolicy() {}
 //        virtual ~SillyPolicy() {}
 //        virtual ResultExpr EvaluateSyscall(int sysno) const OVERRIDE {
 //          if (sysno == __NR_fcntl) {
 //            Arg<int> fd(0), cmd(1);
 //            Arg<unsigned long> flags(2);
-//            const unsigned long kBadFlags = ~(O_ACCMODE | O_NONBLOCK);
-//            return If(fd == 0 && cmd == F_SETFL && (flags & kBadFlags) == 0,
+//            const uint64_t kGoodFlags = O_ACCMODE | O_NONBLOCK;
+//            return If(fd == 0 && cmd == F_SETFL && (flags & ~kGoodFlags) == 0,
 //                      Allow())
 //                .ElseIf(cmd == F_DUPFD || cmd == F_DUPFD_CLOEXEC,
 //                        Error(EMFILE))
 //                .Else(Trap(SetFlagHandler, NULL));
 //          } else {
 //            return Allow();
 //          }
 //        }
 //
 //       private:
@@ skipping 322 matching lines @@
 
 template <typename T>
 ResultExpr Caser<T>::Default(ResultExpr result) const {
   return elser_.Else(result);
 }
 
 }  // namespace bpf_dsl
 }  // namespace sandbox
 
 #endif  // SANDBOX_LINUX_BPF_DSL_BPF_DSL_H_