From b56cbdd23834a65682c0b46f367f8679e83bc894 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Fri, 18 Sep 2020 15:55:15 -0700 Subject: Abseil LTS 20200923 What's New: * `absl::StatusOr` has been released. See our [blog post](https://abseil.io/blog/2020-091021-status) for more information. * Abseil Flags reflection interfaces have been released. * Abseil Flags memory usage has been significantly optimized. * Abseil now supports a "hardened" build mode. This build mode enables runtime checks that guard against programming errors that may lead to security vulnerabilities. Notable Fixes: * Sanitizer dynamic annotations like `AnnotateRWLockCreate` that are also defined by the compiler sanitizer implementation are no longer also defined by Abseil. * Sanitizer macros are now prefixed with `ABSL_` to avoid naming collisions. * Sanitizer usage is now automatically detected and no longer requires macros like `ADDRESS_SANITIZER` to be defined on the command line. Breaking Changes: * Abseil no longer contains a `dynamic_annotations` library. Users using a supported build system (Bazel or CMake) are unaffected by this, but users manually specifying link libraries may get an error about a missing linker input. Baseline: 7680a5f8efe32de4753baadbd63e74e59d95bac1 Cherry picks: None --- absl/time/internal/cctz/src/time_zone_format.cc | 165 +++++++++++++++++++----- 1 file changed, 136 insertions(+), 29 deletions(-) (limited to 'absl/time/internal/cctz/src/time_zone_format.cc') diff --git a/absl/time/internal/cctz/src/time_zone_format.cc b/absl/time/internal/cctz/src/time_zone_format.cc index 950b23a1..d8cb0474 100644 --- a/absl/time/internal/cctz/src/time_zone_format.cc +++ b/absl/time/internal/cctz/src/time_zone_format.cc @@ -67,6 +67,48 @@ char* strptime(const char* s, const char* fmt, std::tm* tm) { } #endif +// Convert a cctz::weekday to a tm_wday value (0-6, Sunday = 0). +int ToTmWday(weekday wd) { + switch (wd) { + case weekday::sunday: + return 0; + case weekday::monday: + return 1; + case weekday::tuesday: + return 2; + case weekday::wednesday: + return 3; + case weekday::thursday: + return 4; + case weekday::friday: + return 5; + case weekday::saturday: + return 6; + } + return 0; /*NOTREACHED*/ +} + +// Convert a tm_wday value (0-6, Sunday = 0) to a cctz::weekday. +weekday FromTmWday(int tm_wday) { + switch (tm_wday) { + case 0: + return weekday::sunday; + case 1: + return weekday::monday; + case 2: + return weekday::tuesday; + case 3: + return weekday::wednesday; + case 4: + return weekday::thursday; + case 5: + return weekday::friday; + case 6: + return weekday::saturday; + } + return weekday::sunday; /*NOTREACHED*/ +} + std::tm ToTM(const time_zone::absolute_lookup& al) { std::tm tm{}; tm.tm_sec = al.cs.second(); @@ -84,34 +126,19 @@ std::tm ToTM(const time_zone::absolute_lookup& al) { tm.tm_year = static_cast(al.cs.year() - 1900); } - switch (get_weekday(al.cs)) { - case weekday::sunday: - tm.tm_wday = 0; - break; - case weekday::monday: - tm.tm_wday = 1; - break; - case weekday::tuesday: - tm.tm_wday = 2; - break; - case weekday::wednesday: - tm.tm_wday = 3; - break; - case weekday::thursday: - tm.tm_wday = 4; - break; - case weekday::friday: - tm.tm_wday = 5; - break; - case weekday::saturday: - tm.tm_wday = 6; - break; - } + tm.tm_wday = ToTmWday(get_weekday(al.cs)); tm.tm_yday = get_yearday(al.cs) - 1; tm.tm_isdst = al.is_dst ? 1 : 0; return tm; } +// Returns the week of the year [0:53] given a civil day and the day on +// which weeks are defined to start. +int ToWeek(const civil_day& cd, weekday week_start) { + const civil_day d(cd.year() % 400, cd.month(), cd.day()); + return static_cast((d - prev_weekday(civil_year(d), week_start)) / 7); +} + const char kDigits[] = "0123456789"; // Formats a 64-bit integer in the given field width. Note that it is up @@ -189,7 +216,7 @@ void FormatTM(std::string* out, const std::string& fmt, const std::tm& tm) { // strftime(3) returns the number of characters placed in the output // array (which may be 0 characters). It also returns 0 to indicate // an error, like the array wasn't large enough. To accommodate this, - // the following code grows the buffer size from 2x the format std::string + // the following code grows the buffer size from 2x the format string // length up to 32x. for (std::size_t i = 2; i != 32; i *= 2) { std::size_t buf_size = fmt.size() * i; @@ -290,6 +317,7 @@ const std::int_fast64_t kExp10[kDigits10_64 + 1] = { // - %E#S - Seconds with # digits of fractional precision // - %E*S - Seconds with full fractional precision (a literal '*') // - %E4Y - Four-character years (-999 ... -001, 0000, 0001 ... 9999) +// - %ET - The RFC3339 "date-time" separator "T" // // The standard specifiers from RFC3339_* (%Y, %m, %d, %H, %M, and %S) are // handled internally for performance reasons. strftime(3) is slow due to @@ -354,7 +382,7 @@ std::string format(const std::string& format, const time_point& tp, if (cur == end || (cur - percent) % 2 == 0) continue; // Simple specifiers that we handle ourselves. - if (strchr("YmdeHMSzZs%", *cur)) { + if (strchr("YmdeUuWwHMSzZs%", *cur)) { if (cur - 1 != pending) { FormatTM(&result, std::string(pending, cur - 1), tm); } @@ -375,6 +403,22 @@ std::string format(const std::string& format, const time_point& tp, if (*cur == 'e' && *bp == '0') *bp = ' '; // for Windows result.append(bp, static_cast(ep - bp)); break; + case 'U': + bp = Format02d(ep, ToWeek(civil_day(al.cs), weekday::sunday)); + result.append(bp, static_cast(ep - bp)); + break; + case 'u': + bp = Format64(ep, 0, tm.tm_wday ? tm.tm_wday : 7); + result.append(bp, static_cast(ep - bp)); + break; + case 'W': + bp = Format02d(ep, ToWeek(civil_day(al.cs), weekday::monday)); + result.append(bp, static_cast(ep - bp)); + break; + case 'w': + bp = Format64(ep, 0, tm.tm_wday); + result.append(bp, static_cast(ep - bp)); + break; case 'H': bp = Format02d(ep, al.cs.hour()); result.append(bp, static_cast(ep - bp)); @@ -448,7 +492,14 @@ std::string format(const std::string& format, const time_point& tp, if (*cur != 'E' || ++cur == end) continue; // Format our extensions. - if (*cur == 'z') { + if (*cur == 'T') { + // Formats %ET. + if (cur - 2 != pending) { + FormatTM(&result, std::string(pending, cur - 2), tm); + } + result.append("T"); + pending = ++cur; + } else if (*cur == 'z') { // Formats %Ez. if (cur - 2 != pending) { FormatTM(&result, std::string(pending, cur - 2), tm); @@ -551,7 +602,7 @@ const char* ParseOffset(const char* dp, const char* mode, int* offset) { } else { dp = nullptr; } - } else if (first == 'Z') { // Zulu + } else if (first == 'Z' || first == 'z') { // Zulu *offset = 0; } else { dp = nullptr; @@ -602,12 +653,32 @@ const char* ParseTM(const char* dp, const char* fmt, std::tm* tm) { return dp; } +// Sets year, tm_mon and tm_mday given the year, week_num, and tm_wday, +// and the day on which weeks are defined to start. Returns false if year +// would need to move outside its bounds. +bool FromWeek(int week_num, weekday week_start, year_t* year, std::tm* tm) { + const civil_year y(*year % 400); + civil_day cd = prev_weekday(y, week_start); // week 0 + cd = next_weekday(cd - 1, FromTmWday(tm->tm_wday)) + (week_num * 7); + if (const year_t shift = cd.year() - y.year()) { + if (shift > 0) { + if (*year > std::numeric_limits::max() - shift) return false; + } else { + if (*year < std::numeric_limits::min() - shift) return false; + } + *year += shift; + } + tm->tm_mon = cd.month() - 1; + tm->tm_mday = cd.day(); + return true; +} + } // namespace // Uses strptime(3) to parse the given input. Supports the same extended // format specifiers as format(), although %E#S and %E*S are treated // identically (and similarly for %E#f and %E*f). %Ez and %E*z also accept -// the same inputs. +// the same inputs. %ET accepts either 'T' or 't'. // // The standard specifiers from RFC3339_* (%Y, %m, %d, %H, %M, and %S) are // handled internally so that we can normally avoid strptime() altogether @@ -651,6 +722,8 @@ bool parse(const std::string& format, const std::string& input, const char* fmt = format.c_str(); // NUL terminated bool twelve_hour = false; bool afternoon = false; + int week_num = -1; + weekday week_start = weekday::sunday; bool saw_percent_s = false; std::int_fast64_t percent_s = 0; @@ -689,10 +762,27 @@ bool parse(const std::string& format, const std::string& input, case 'm': data = ParseInt(data, 2, 1, 12, &tm.tm_mon); if (data != nullptr) tm.tm_mon -= 1; + week_num = -1; continue; case 'd': case 'e': data = ParseInt(data, 2, 1, 31, &tm.tm_mday); + week_num = -1; + continue; + case 'U': + data = ParseInt(data, 0, 0, 53, &week_num); + week_start = weekday::sunday; + continue; + case 'W': + data = ParseInt(data, 0, 0, 53, &week_num); + week_start = weekday::monday; + continue; + case 'u': + data = ParseInt(data, 0, 1, 7, &tm.tm_wday); + if (data != nullptr) tm.tm_wday %= 7; + continue; + case 'w': + data = ParseInt(data, 0, 0, 6, &tm.tm_wday); continue; case 'H': data = ParseInt(data, 2, 0, 23, &tm.tm_hour); @@ -742,6 +832,15 @@ bool parse(const std::string& format, const std::string& input, data = (*data == '%' ? data + 1 : nullptr); continue; case 'E': + if (fmt[0] == 'T') { + if (*data == 'T' || *data == 't') { + ++data; + ++fmt; + } else { + data = nullptr; + } + continue; + } if (fmt[0] == 'z' || (fmt[0] == '*' && fmt[1] == 'z')) { data = ParseOffset(data, ":", &offset); if (data != nullptr) saw_offset = true; @@ -839,7 +938,7 @@ bool parse(const std::string& format, const std::string& input, // Skip any remaining whitespace. while (std::isspace(*data)) ++data; - // parse() must consume the entire input std::string. + // parse() must consume the entire input string. if (*data != '\0') { if (err != nullptr) *err = "Illegal trailing data in input string"; return false; @@ -874,6 +973,14 @@ bool parse(const std::string& format, const std::string& input, year += 1900; } + // Compute year, tm.tm_mon and tm.tm_mday if we parsed a week number. + if (week_num != -1) { + if (!FromWeek(week_num, week_start, &year, &tm)) { + if (err != nullptr) *err = "Out-of-range field"; + return false; + } + } + const int month = tm.tm_mon + 1; civil_second cs(year, month, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); -- cgit v1.2.3