Reapply "Refactor Date implementation in VM."

runtime/vm/os_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/os.h"
 
 #include <errno.h>
 #include <limits.h>
 #include <time.h>
 #include <sys/resource.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include "platform/utils.h"
 #include "vm/isolate.h"
 
 namespace dart {
 
-bool OS::GmTime(int64_t seconds_since_epoch, tm* tm_result) {
-  time_t seconds = static_cast<time_t>(seconds_since_epoch);
-  if (seconds != seconds_since_epoch) return false;
-  struct tm* error_code = gmtime_r(&seconds, tm_result);
-  return error_code != NULL;
-}
-
-
-bool OS::LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
+static bool LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
   time_t seconds = static_cast<time_t>(seconds_since_epoch);
   if (seconds != seconds_since_epoch) return false;
   struct tm* error_code = localtime_r(&seconds, tm_result);
   return error_code != NULL;
 }
 
 
-bool OS::MkGmTime(tm* tm, int64_t* seconds_result) {
-  // Set wday to an impossible day, so that we can catch bad input.
-  tm->tm_wday = -1;
-  time_t seconds = timegm(tm);
-  if ((seconds == -1) && (tm->tm_wday == -1)) {
-    return false;
-  }
-  *seconds_result = seconds;
-  return true;
+const char* OS::GetTimeZoneName(int64_t seconds_since_epoch) {
+  tm decomposed;
+  bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
+  ASSERT(succeeded);
+  return decomposed.tm_zone;
 }
 
 
-bool OS::MkTime(tm* tm, int64_t* seconds_result) {
-  // Let the libc figure out if daylight saving is active.
-  tm->tm_isdst = -1;
-  // Set wday to an impossible day, so that we can catch bad input.
-  tm->tm_wday = -1;
-  time_t seconds = mktime(tm);
-  if ((seconds == -1) && (tm->tm_wday == -1)) {
-    return false;
-  }
-  *seconds_result = seconds;
-  return true;
+int OS::GetTimeZoneOffsetInSeconds(int64_t seconds_since_epoch) {
+  tm decomposed;
+  bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
+  ASSERT(succeeded);
+  // Even if the offset was 24 hours it would still easily fit into 32 bits.
+  return static_cast<int>(decomposed.tm_gmtoff);
 }
 
 
-bool OS::GetTimeZoneName(int64_t seconds_since_epoch,
-                         const char** name_result) {
-  tm decomposed;
-  bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
-  if (!succeeded) return false;
-  *name_result = decomposed.tm_zone;
-  return true;
+int OS::GetLocalTimeZoneAdjustmentInSeconds() {
+  // TODO(floitsch): avoid excessive calls to tzset?
+  tzset();
+  // Even if the offset was 24 hours it would still easily fit into 32 bits.
+  // Note that Unix and Dart disagree on the sign.
+  return static_cast<int>(-timezone);
 }
 
 
-bool OS::GetTimeZoneOffsetInSeconds(int64_t seconds_since_epoch,
-                                    int* offset_result) {
-  tm decomposed;
-  bool succeeded = LocalTime(seconds_since_epoch, &decomposed);
-  if (!succeeded) return false;
-  // Even if the offset was 24 hours it would still easily fit into 32 bits.
-  *offset_result = static_cast<int>(decomposed.tm_gmtoff);
-  return true;
-}
-
-
 int64_t OS::GetCurrentTimeMillis() {
   return GetCurrentTimeMicros() / 1000;
 }
 
 
 int64_t OS::GetCurrentTimeMicros() {
   // gettimeofday has microsecond resolution.
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0) {
     UNREACHABLE();
@@ skipping 129 matching lines @@
 void OS::Abort() {
   abort();
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart