Add UUID, strlcpy, and their tests to util

util/misc/uuid.h

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CRASHPAD_UTIL_MISC_UUID_H_
+#define CRASHPAD_UTIL_MISC_UUID_H_
+
+#include <stdint.h>
+
+namespace crashpad {
+
+//! \brief A universally unique identifier (%UUID).
+//!
+//! An alternate term for %UUID is “globally unique identifier” (GUID), used
+//! primarily by Microsoft.
+//!
+//! A %UUID is a unique 128-bit number specified by RFC 4122.
+struct UUID {

[Robert Sesek, 2014/08/01 17:28:18]

No default constructor to zero-initialize everything?

[Mark Mentovai, 2014/08/01 18:05:49]

rsesek wrote:
I kinda wanted to keep it POD, but maybe it’s enough that it’s standard layout
now that we’re using C++11?

+  //! \brief Initializes the %UUID from a sequence of bytes.
+  //!
+  //! \a bytes is taken as a %UUID laid out in big-endian format in memory. On
+  //! little-endian machines, appropriate byte-swapping will be performed to
+  //! initialize an object’s data members.
+  //!
+  //! \param[in] bytes A buffer of exactly 16 bytes that will be assigned to the
+  //!     %UUID.
+  void InitializeFromBytes(const uint8_t* bytes);
+
+  //! \brief The contents of the %UUID.
+  //! \{
+  uint32_t data_1;
+  uint16_t data_2;
+  uint16_t data_3;
+  uint8_t data_4[8];

[Robert Sesek, 2014/08/01 17:28:18]

You may want to split data_4 into two fields: data_4[2] and data_5[6]. Because
the string representation of a UUID actually contains five fields:
29C24D52-A794-4887-B392-C855C155A28C, per the RFC:

"""
 UUID                   = time-low "-" time-mid "-"
                               time-high-and-version "-"
                               clock-seq-and-reserved
                               clock-seq-low "-" node
      time-low               = 4hexOctet
      time-mid               = 2hexOctet
      time-high-and-version  = 2hexOctet
      clock-seq-and-reserved = hexOctet
      clock-seq-low          = hexOctet
      node                   = 6hexOctet
      hexOctet               = hexDigit hexDigit
"""

And just for contrast, uuid_t on Mac is just a unsigned char[16].

[Mark Mentovai, 2014/08/01 18:05:49]

rsesek wrote:
This definition came from Microsoft’s GUID definition, but we don’t actually use
that anywhere (which is why I renamed this to UUID). I was concerned about
byte-swapping, but if we always treat it as a uint8_t[16], we don’t really need
to worry about that. I’ll change it.

+  //! \}
+};
+

[Robert Sesek, 2014/08/01 17:28:18]

A little surprised to not see an ostream operator or a ToString() method.

+}  // namespace crashpad
+
+#endif  // CRASHPAD_UTIL_MISC_UUID_H_