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[WIP] Basic structures for strftime
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11 files changed

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‎libc/src/stdio/CMakeLists.txt

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@@ -239,6 +239,7 @@ add_entrypoint_object(
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add_subdirectory(printf_core)
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add_subdirectory(scanf_core)
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add_subdirectory(strftime_core)
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add_entrypoint_object(
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remove

‎libc/src/stdio/strftime_core/CMakeLists.txt

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add_header_library(
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core_structs
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HDRS
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core_structs.h
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DEPENDS
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libc.src.__support.CPP.string_view
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libc.src.__support.FPUtil.fp_bits
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)
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add_header_library(
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parser
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HDRS
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parser.h
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DEPENDS
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.core_structs
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libc.src.__support.arg_list
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libc.src.__support.ctype_utils
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libc.src.__support.str_to_integer
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libc.src.__support.CPP.algorithm
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libc.src.__support.CPP.bit
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libc.src.__support.CPP.optional
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libc.src.__support.CPP.string_view
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libc.src.__support.CPP.type_traits
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libc.src.__support.common
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)
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add_object_library(
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converter
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SRCS
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converter.cpp
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HDRS
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converter.h
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DEPENDS
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.core_structs
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libc.src.stdio.printf_core.writer
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libc.src.__support.big_int
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libc.src.math.log10
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libc.src.__support.common
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libc.src.__support.CPP.limits
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libc.src.__support.CPP.span
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libc.src.__support.CPP.string_view
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libc.src.__support.float_to_string
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libc.src.__support.FPUtil.fenv_impl
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libc.src.__support.FPUtil.fp_bits
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libc.src.__support.FPUtil.rounding_mode
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libc.src.__support.integer_to_string
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libc.src.__support.libc_assert
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libc.src.__support.uint128
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libc.src.__support.StringUtil.error_to_string
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)

‎libc/src/stdio/strftime_core/converter.cpp

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//===-- Format specifier converter for printf -------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
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#define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
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#include "src/__support/CPP/string.h"
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#include "src/__support/CPP/string_view.h"
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#include "src/__support/integer_to_string.h"
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#include "src/__support/macros/config.h"
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#include "src/math/log10.h"
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#include "src/stdio/printf_core/writer.h"
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#include "src/stdio/strftime_core/core_structs.h"
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#include "src/stdio/strftime_core/time_internal_def.h"
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#include <time.h>
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namespace LIBC_NAMESPACE_DECL {
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namespace strftime_core {
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namespace details {
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LIBC_INLINE cpp::optional<cpp::string_view>
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num_to_strview(uintmax_t num, cpp::span<char> bufref) {
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return IntegerToString<uintmax_t>::format_to(bufref, num);
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}
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template<int width>
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LIBC_INLINE int write_num(uintmax_t num,
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printf_core::Writer *writer) {
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cpp::array<char, width> buf;
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return writer->write(*num_to_strview(num, buf));
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}
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template <int width, char padding>
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LIBC_INLINE int write_num_with_padding(uintmax_t num,
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printf_core::Writer *writer) {
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cpp::array<char, width> buf;
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auto digits = log10(num) + 1;
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auto padding_needed = width - digits;
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int char_written = 0;
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for (int _ = 0; _ < padding_needed; _++) {
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char_written += writer->write(padding);
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}
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char_written += writer->write(*num_to_strview(num, buf));
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return char_written;
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}
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} // namespace details
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LIBC_INLINE int convert_weekday(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return writer->write(day_names[to_conv.time->tm_wday]);
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}
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LIBC_INLINE int convert_zero_padded_day_of_year(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<3, '0'>(to_conv.time->tm_yday + 1, writer);
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}
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LIBC_INLINE int convert_zero_padded_day_of_month(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<2, '0'>(to_conv.time->tm_mday, writer);
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}
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LIBC_INLINE int convert_space_padded_day_of_month(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<2, ' '>(to_conv.time->tm_mday, writer);
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}
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LIBC_INLINE int convert_decimal_weekday(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num<1>(to_conv.time->tm_wday == 0 ? 7 : to_conv.time->tm_wday, writer);
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}
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LIBC_INLINE int convert_decimal_weekday_iso(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num<1>(to_conv.time->tm_wday, writer);
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}
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LIBC_INLINE int convert_week_number_sunday(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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int wday = to_conv.time->tm_wday;
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int yday = to_conv.time->tm_yday;
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int week = (yday - wday + 7) / 7;
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return details::write_num_with_padding<2, '0'>(week, writer);
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}
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LIBC_INLINE int convert_week_number_monday(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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int wday = (to_conv.time->tm_wday + 6) % 7;
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int yday = to_conv.time->tm_yday;
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int week = (yday - wday + 7) / 7;
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return details::write_num_with_padding<2, '0'>(week, writer);
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}
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LIBC_INLINE int convert_full_month(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return writer->write(month_names[to_conv.time->tm_mon]);
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}
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LIBC_INLINE int convert_abbreviated_month(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return writer->write(abbreviated_month_names[to_conv.time->tm_mon]);
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}
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LIBC_INLINE int convert_zero_padded_month(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<2, '0'>(to_conv.time->tm_mon + 1, writer);
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}
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LIBC_INLINE int convert_full_year(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<4, '0'>(to_conv.time->tm_year + 1900, writer);
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}
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LIBC_INLINE int convert_two_digit_year(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<2, '0'>((to_conv.time->tm_year + 1900) % 100, writer);
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}
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LIBC_INLINE int convert_century(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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return details::write_num_with_padding<2, '0'>((to_conv.time->tm_year + 1900) / 100, writer);
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}
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LIBC_INLINE int convert_iso_year(printf_core::Writer *writer,
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const FormatSection &to_conv) {
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// TODO
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return details::write_num_with_padding<4, '0'>(to_conv.time->tm_year + 1900, writer);
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}
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int convert(printf_core::Writer *writer, const FormatSection &to_conv) {
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if (!to_conv.has_conv)
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return writer->write(to_conv.raw_string);
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switch (to_conv.conv_name) {
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// day of the week
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case 'a':
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return convert_weekday(writer, to_conv);
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case 'w':
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return convert_decimal_weekday(writer, to_conv);
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case 'u':
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return convert_decimal_weekday_iso(writer, to_conv);
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// day of the year/ month
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case 'j':
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return convert_zero_padded_day_of_year(writer, to_conv);
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case 'd':
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return convert_zero_padded_day_of_month(writer, to_conv);
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case 'e':
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return convert_space_padded_day_of_month(writer, to_conv);
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// week
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case 'U':
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return convert_week_number_sunday(writer, to_conv);
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case 'W':
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return convert_week_number_monday(writer, to_conv);
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case 'V': // TODO: ISO 8061
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// month
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case 'B':
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return convert_full_month(writer, to_conv);
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case 'b':
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case 'h':
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return convert_abbreviated_month(writer, to_conv);
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case 'm':
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return convert_zero_padded_month(writer, to_conv);
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// year
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case 'Y': // Full year (e.g., 2024)
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return convert_full_year(writer, to_conv);
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case 'y': // Two-digit year (e.g., 24 for 2024)
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return convert_two_digit_year(writer, to_conv);
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case 'C': // Century (e.g., 20 for 2024)
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return convert_century(writer, to_conv);
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case 'G': // ISO 8601 year
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// TODO
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return convert_iso_year(writer, to_conv);
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}
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return 0;
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}
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} // namespace strftime_core
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} // namespace LIBC_NAMESPACE_DECL
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#endif

‎libc/src/stdio/strftime_core/converter.h

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//===-- Format specifier converter for printf -------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
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#define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H
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#include "src/__support/macros/config.h"
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#include "src/stdio/strftime_core/core_structs.h"
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#include "src/stdio/printf_core/writer.h"
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#include <stddef.h>
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namespace LIBC_NAMESPACE_DECL {
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namespace strftime_core {
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// convert will call a conversion function to convert the FormatSection into
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// its string representation, and then that will write the result to the
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// writer.
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int convert(printf_core::Writer *writer, const FormatSection &to_conv);
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} // namespace strftime_core
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} // namespace LIBC_NAMESPACE_DECL
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#endif // LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CONVERTER_H

‎libc/src/stdio/strftime_core/core_structs.h

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//===-- Core Structures for printf ------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CORE_STRUCTS_H
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#define LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CORE_STRUCTS_H
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#include "src/__support/macros/config.h"
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#include "src/__support/CPP/string_view.h"
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#include "src/__support/CPP/type_traits.h"
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#include "src/__support/FPUtil/FPBits.h"
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#include <inttypes.h>
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#include <stddef.h>
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namespace LIBC_NAMESPACE_DECL {
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namespace strftime_core {
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struct tm {
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int tm_sec; /* seconds after the minute [0-60] */
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int tm_min; /* minutes after the hour [0-59] */
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int tm_hour; /* hours since midnight [0-23] */
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int tm_mday; /* day of the month [1-31] */
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int tm_mon; /* months since January [0-11] */
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int tm_year; /* years since 1900 */
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int tm_wday; /* days since Sunday [0-6] */
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int tm_yday; /* days since January 1 [0-365] */
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int tm_isdst; /* Daylight Savings Time flag */
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long tm_gmtoff; /* offset from UTC in seconds */
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char *tm_zone; /* timezone abbreviation */
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};
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struct FormatSection {
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bool has_conv {false};
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bool isE {false};
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bool isO {false};
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cpp::string_view raw_string;
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char conv_name;
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const struct tm *time;
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};
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enum PrimaryType : uint8_t {
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Unknown = 0,
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Float = 1,
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Pointer = 2,
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Integer = 3,
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FixedPoint = 4,
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};
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// TypeDesc stores the information about a type that is relevant to printf in
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// a relatively compact manner.
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struct TypeDesc {
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uint8_t size;
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PrimaryType primary_type;
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LIBC_INLINE constexpr bool operator==(const TypeDesc &other) const {
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return (size == other.size) && (primary_type == other.primary_type);
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}
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};
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template <typename T> LIBC_INLINE constexpr TypeDesc type_desc_from_type() {
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if constexpr (cpp::is_same_v<T, void>) {
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return TypeDesc{0, PrimaryType::Unknown};
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} else {
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constexpr bool IS_POINTER = cpp::is_pointer_v<T>;
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constexpr bool IS_FLOAT = cpp::is_floating_point_v<T>;
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#ifdef LIBC_INTERNAL_STRFTIME_HAS_FIXED_POINT
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constexpr bool IS_FIXED_POINT = cpp::is_fixed_point_v<T>;
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#else
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constexpr bool IS_FIXED_POINT = false;
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#endif // LIBC_INTERNAL_STRFTIME_HAS_FIXED_POINT
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return TypeDesc{sizeof(T), IS_POINTER ? PrimaryType::Pointer
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: IS_FLOAT ? PrimaryType::Float
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: IS_FIXED_POINT ? PrimaryType::FixedPoint
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: PrimaryType::Integer};
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}
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}
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// This is the value to be returned by conversions when no error has occurred.
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constexpr int WRITE_OK = 0;
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// These are the printf return values for when an error has occurred. They are
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// all negative, and should be distinct.
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constexpr int FILE_WRITE_ERROR = -1;
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constexpr int FILE_STATUS_ERROR = -2;
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constexpr int NULLPTR_WRITE_ERROR = -3;
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constexpr int INT_CONVERSION_ERROR = -4;
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constexpr int FIXED_POINT_CONVERSION_ERROR = -5;
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constexpr int ALLOCATION_ERROR = -6;
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} // namespace strftime_core
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} // namespace LIBC_NAMESPACE_DECL
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#endif // LLVM_LIBC_SRC_STDIO_STRFTIME_CORE_CORE_STRUCTS_H

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