win: Add UUID::InitializeFromSystemUUID().

The new call is also used in
CrashReportDatabaseWin::PrepareNewCrashReport(). Previously, that method
used the UUID::InitializeFromBytes() constructor. That actually caused
various fields of the UUID to be byte-swapped so that the ::UUID and
crashpad::UUID would be different UUIDs. Although a UUID is mostly
random, the version field in data_3 is used as a namespace and should be
4 for random UUIDs, and this was not the case under swapping.

TEST=crashpad_util_test UUID.FromSystem
BUG=crashpad:1
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/1004913004

client/crash_report_database_win.cc

@@ -576,12 +576,9 @@ OperationStatus CrashReportDatabaseWin::PrepareNewCrashReport(
   ::UUID system_uuid;
   if (UuidCreate(&system_uuid) != RPC_S_OK)
     return kFileSystemError;
-  static_assert(sizeof(system_uuid) == 16, "unexpected system uuid size");
-  static_assert(offsetof(::UUID, Data1) == 0, "unexpected uuid layout");
 
   scoped_ptr<NewReport> new_report(new NewReport());
-  new_report->uuid.InitializeFromBytes(
-      reinterpret_cast<const uint8_t*>(&system_uuid.Data1));
+  new_report->uuid.InitializeFromSystemUUID(&system_uuid);
   new_report->path = base_dir_.Append(kReportsDirectory)
                          .Append(new_report->uuid.ToString16() + L"." +
                                  kCrashReportFileExtension);

util/misc/uuid.cc

@@ -88,6 +88,16 @@ bool UUID::InitializeFromString(const base::StringPiece& string) {
   return true;
 }
 
+#if defined(OS_WIN)
+void UUID::InitializeFromSystemUUID(const ::UUID* system_uuid) {
+  static_assert(sizeof(::UUID) == sizeof(UUID),
+                "unexpected system uuid size");
+  static_assert(offsetof(::UUID, Data1) == offsetof(UUID, data_1),
+                "unexpected system uuid layout");
+  memcpy(this, system_uuid, sizeof(::UUID));
+}
+#endif  // OS_WIN
+
 std::string UUID::ToString() const {
   return base::StringPrintf("%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
                             data_1,

util/misc/uuid.h

@@ -23,6 +23,10 @@
 #include "base/strings/string_piece.h"
 #include "build/build_config.h"
 
+#if defined(OS_WIN)
+#include <rpc.h>
+#endif
+
 namespace crashpad {
 
 //! \brief A universally unique identifier (%UUID).
@@ -63,12 +67,19 @@ struct UUID {
   //!     parsed, with the object state untouched.
   bool InitializeFromString(const base::StringPiece& string);
 
+#if defined(OS_WIN) || DOXYGEN
+  //! \brief Initializes the %UUID from a system `UUID` or `GUID` structure.
+  //!
+  //! \param[in] system_uuid A system `UUID` or `GUID` structure.
+  void InitializeFromSystemUUID(const ::UUID* system_uuid);
+#endif  // OS_WIN
+
   //! \brief Formats the %UUID per RFC 4122 §3.
   //!
   //! \return A string of the form `"00112233-4455-6677-8899-aabbccddeeff"`.
   std::string ToString() const;
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) || DOXYGEN
   //! \brief The same as ToString, but returned as a string16.
   base::string16 ToString16() const;
 #endif  // OS_WIN

util/misc/uuid_test.cc

@@ -20,6 +20,7 @@
 
 #include "base/basictypes.h"
 #include "base/format_macros.h"
+#include "base/scoped_generic.h"
 #include "base/strings/stringprintf.h"
 #include "gtest/gtest.h"
 
@@ -204,6 +205,33 @@ TEST(UUID, FromString) {
   EXPECT_EQ("5762c15d-50b5-4171-a2e9-7429c9ec6cab", uuid.ToString());
 }
 
+#if defined(OS_WIN)
+
+TEST(UUID, FromSystem) {
+  ::GUID system_uuid;
+  ASSERT_EQ(RPC_S_OK, UuidCreate(&system_uuid));
+
+  UUID uuid;
+  uuid.InitializeFromSystemUUID(&system_uuid);
+
+  RPC_WSTR system_string;
+  ASSERT_EQ(RPC_S_OK, UuidToString(&system_uuid, &system_string));
+
+  struct ScopedRpcStringFreeTraits {
+    static RPC_WSTR* InvalidValue() { return nullptr; }
+    static void Free(RPC_WSTR* rpc_string) {
+      EXPECT_EQ(RPC_S_OK, RpcStringFree(rpc_string));
+    }
+  };
+  using ScopedRpcString =
+      base::ScopedGeneric<RPC_WSTR*, ScopedRpcStringFreeTraits>;
+  ScopedRpcString scoped_system_string(&system_string);
+
+  EXPECT_EQ(reinterpret_cast<wchar_t*>(system_string), uuid.ToString16());
+}
+
+#endif  // OS_WIN
+
 }  // namespace
 }  // namespace test
 }  // namespace crashpad

util/util.gyp

@@ -208,6 +208,7 @@
         ['OS=="win"', {
           'link_settings': {
             'libraries': [
+              '-lrpcrt4.lib',
               '-lwinhttp.lib',
             ],
           },