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| 1 | +//===-- Linux implementation of the localtime function --------------------===// |
| 2 | +// |
| 3 | +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | +// See https://llvm.org/LICENSE.txt for license information. |
| 5 | +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | +// |
| 7 | +//===----------------------------------------------------------------------===// |
| 8 | + |
| 9 | +#include "localtime_utils.h" |
| 10 | +#include "src/time/linux/timezone.h" |
| 11 | +#include "src/time/time_utils.h" |
| 12 | + |
| 13 | +namespace LIBC_NAMESPACE_DECL { |
| 14 | +namespace localtime_utils { |
| 15 | + |
| 16 | +timezone::tzset *get_localtime(struct tm *tm) { |
| 17 | + char *tz_filename = time_utils::get_env_var("TZ"); |
| 18 | + if ((tz_filename == nullptr) == 1 || tz_filename[0] == '\0') { |
| 19 | + static char localtime[] = "/etc/localtime"; |
| 20 | + tz_filename = localtime; |
| 21 | + } else { |
| 22 | + char tmp[64]; |
| 23 | + char prefix[21] = "/usr/share/zoneinfo/"; |
| 24 | + size_t i = 0; |
| 25 | + while (prefix[i] != '\0') { |
| 26 | + tmp[i] = prefix[i]; |
| 27 | + i++; |
| 28 | + } |
| 29 | + |
| 30 | + i = 0; |
| 31 | + while (tz_filename[i] != '\0') { |
| 32 | + tmp[i + 20] = tz_filename[i]; |
| 33 | + i++; |
| 34 | + } |
| 35 | + |
| 36 | + tz_filename = tmp; |
| 37 | + while (tz_filename[i] != '\0') { |
| 38 | + if (tz_filename[i] == (char)0xFFFFFFAA) { |
| 39 | + tz_filename[i] = '\0'; |
| 40 | + } |
| 41 | + i++; |
| 42 | + } |
| 43 | + } |
| 44 | + |
| 45 | + ErrorOr<File *> error_or_file = time_utils::acquire_file(tz_filename); |
| 46 | + File *file = error_or_file.value(); |
| 47 | + |
| 48 | + timezone::tzset *ptr_tzset = timezone::get_tzset(file); |
| 49 | + if (ptr_tzset == nullptr) { |
| 50 | + time_utils::release_file(file); |
| 51 | + return nullptr; |
| 52 | + } |
| 53 | + |
| 54 | + for (size_t i = 0; i < *ptr_tzset->ttinfo->size; i++) { |
| 55 | + if (time_utils::is_dst(tm) == ptr_tzset->ttinfo[i].tt_isdst) { |
| 56 | + ptr_tzset->global_offset = |
| 57 | + static_cast<int8_t>(ptr_tzset->ttinfo[i].tt_utoff / 3600); |
| 58 | + ptr_tzset->global_isdst = |
| 59 | + static_cast<int8_t>(ptr_tzset->ttinfo[i].tt_isdst); |
| 60 | + } |
| 61 | + } |
| 62 | + |
| 63 | + if (time_utils::file_usage == 1) { |
| 64 | + time_utils::release_file(file); |
| 65 | + } |
| 66 | + |
| 67 | + return ptr_tzset; |
| 68 | +} |
| 69 | + |
| 70 | +} // namespace localtime_utils |
| 71 | +} // namespace LIBC_NAMESPACE_DECL |
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