Add: check exploded time is properly converted

base/time/time.h

 // Copyright (c) 2012 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.
 
 // Time represents an absolute point in coordinated universal time (UTC),
 // internally represented as microseconds (s/1,000,000) since the Windows epoch
 // (1601-01-01 00:00:00 UTC). System-dependent clock interface routines are
 // defined in time_PLATFORM.cc. Note that values for Time may skew and jump
 // around as the operating system makes adjustments to synchronize (e.g., with
 // NTP servers). Thus, client code that uses the Time class must account for
@@ skipping 402 matching lines @@
     int hour;          // Hour within the current day (0-23)
     int minute;        // Minute within the current hour (0-59)
     int second;        // Second within the current minute (0-59 plus leap
                        //   seconds which may take it up to 60).
     int millisecond;   // Milliseconds within the current second (0-999)
 
     // A cursory test for whether the data members are within their
     // respective ranges. A 'true' return value does not guarantee the
     // Exploded value can be successfully converted to a Time value.
     bool HasValidValues() const;
+    bool operator!=(const Exploded& rhs);
   };
 
   // Contains the NULL time. Use Time::Now() to get the current time.
   Time() : TimeBase(0) {
   }
 
   // Returns the time for epoch in Unix-like system (Jan 1, 1970).
   static Time UnixEpoch();
 
   // Returns the current time. Watch out, the system might adjust its clock
@@ skipping 82 matching lines @@
 
   // Converts an exploded structure representing either the local time or UTC
   // into a Time class.
   static Time FromUTCExploded(const Exploded& exploded) {
     return FromExploded(false, exploded);
   }
   static Time FromLocalExploded(const Exploded& exploded) {
     return FromExploded(true, exploded);
   }
 
+  // Converts an exploded structure representing either the local time or UTC
+  // into a Time class.
+  // This is a transition to a new format, where the converted time is set to
+  // |time| and FromUTCExploded, FromLocalExploded and FromExploded return true
+  // on success or false on failure. For example, FromExploded can fail when
+  // 31st of a month is set on a 28-30 day month, which results in 1st day of
+  // the next month.
+  static bool FromUTCExploded(const Exploded& exploded, Time& time) {

[mmenke, 2016/05/20 19:44:56]

Per Google C++ style guide, non-const refs are forbidden.  These should be
passing in a Time*.

[maksims (do not use this acc), 2016/05/24 09:14:21]

Done.

+    return FromExploded(false, exploded, time);
+  }
+  static bool FromLocalExploded(const Exploded& exploded, Time& time) {

[mmenke, 2016/05/20 19:44:56]

These two should use WARN_UNUSED_RESULT.

[maksims (do not use this acc), 2016/05/24 09:14:21]

Done.

+    return FromExploded(true, exploded, time);
+  }

[mmenke, 2016/05/20 19:44:56]

Is the plan to replace calls to the old methods with calls to these?

[maksims (do not use this acc), 2016/05/24 09:14:21]

Yes, I would like to do so.

+
   // Converts a string representation of time to a Time object.
   // An example of a time string which is converted is as below:-
   // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified
   // in the input string, FromString assumes local time and FromUTCString
   // assumes UTC. A timezone that cannot be parsed (e.g. "UTC" which is not
   // specified in RFC822) is treated as if the timezone is not specified.
   // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to
   // a new time converter class.
   static bool FromString(const char* time_string, Time* parsed_time) {
     return FromStringInternal(time_string, true, parsed_time);
@@ skipping 19 matching lines @@
   friend class time_internal::TimeBase<Time>;
 
   explicit Time(int64_t us) : TimeBase(us) {}
 
   // Explodes the given time to either local time |is_local = true| or UTC
   // |is_local = false|.
   void Explode(bool is_local, Exploded* exploded) const;
 
   // Unexplodes a given time assuming the source is either local time
   // |is_local = true| or UTC |is_local = false|.
   static Time FromExploded(bool is_local, const Exploded& exploded);

[mmenke, 2016/05/20 19:44:56]

If we're going to keep the old methods around (Permanently?  Temporarily?), we
should probably still get rid of this method, and make the two old public
functions wrap the new FromExploded function.

Also, since the new methods have WARN_UNUSED_RESULT in the new methods, you'll
need to use ignore_result on the calls in the two old methods to the new
FromExploded method.

[maksims (do not use this acc), 2016/05/24 09:14:21]

Done.

 
+  // Unexplodes a given time assuming the source is either local time
+  // |is_local = true| or UTC |is_local = false|.
+  // This is a transition to a newer form. Function returns false on failure
+  // and sets |time| to Time(0). Otherwise returns true and sets |time| to
+  // non-exploded time.
+  static bool FromExploded(bool is_local, const Exploded& exploded, Time& time);

[mmenke, 2016/05/20 19:44:56]

WARN_UNUSED_RESULT

[maksims (do not use this acc), 2016/05/24 09:14:21]

Done.

+
   // Converts a string representation of time to a Time object.
   // An example of a time string which is converted is as below:-
   // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified
   // in the input string, local time |is_local = true| or
   // UTC |is_local = false| is assumed. A timezone that cannot be parsed
   // (e.g. "UTC" which is not specified in RFC822) is treated as if the
   // timezone is not specified.
   static bool FromStringInternal(const char* time_string,
                                  bool is_local,
                                  Time* parsed_time);
@@ skipping 200 matching lines @@
   static void WaitUntilInitializedWin();
 #endif
 };
 
 // For logging use only.
 BASE_EXPORT std::ostream& operator<<(std::ostream& os, ThreadTicks time_ticks);
 
 }  // namespace base
 
 #endif  // BASE_TIME_TIME_H_