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@@ -0,0 +1,1356 @@
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+/*
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+ * Copyright (c) 2006-2024, RT-Thread Development Team
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+ *
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+ * SPDX-License-Identifier: Apache-2.0
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+ *
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+ * Change Logs:
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+ * Date Author Notes
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+ * 2021-11-27 Meco Man porting for rt_vsnprintf as the fully functional version
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+ * 2024-11-19 Meco Man move into rtklibc
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+ */
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+
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+/**
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+ * @author (c) Eyal Rozenberg <eyalroz1@gmx.com>
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+ * 2021-2022, Haifa, Palestine/Israel
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+ * @author (c) Marco Paland (info@paland.com)
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+ * 2014-2019, PALANDesign Hannover, Germany
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+ *
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+ * @note Others have made smaller contributions to this file: see the
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+ * contributors page at https://github.com/eyalroz/printf/graphs/contributors
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+ * or ask one of the authors. The original code for exponential specifiers was
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+ * contributed by Martijn Jasperse <m.jasperse@gmail.com>.
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+ *
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+ * @brief Small stand-alone implementation of the printf family of functions
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+ * (`(v)printf`, `(v)s(n)printf` etc., geared towards use on embedded systems with
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+ * a very limited resources.
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+ *
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+ * @note the implementations are thread-safe; re-entrant; use no functions from
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+ * the standard library; and do not dynamically allocate any memory.
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+ *
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+ * @license The MIT License (MIT)
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+ *
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+ * Permission is hereby granted, free of charge, to any person obtaining a copy
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+ * of this software and associated documentation files (the "Software"), to deal
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+ * in the Software without restriction, including without limitation the rights
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+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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+ * copies of the Software, and to permit persons to whom the Software is
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+ * furnished to do so, subject to the following conditions:
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+ *
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+ * The above copyright notice and this permission notice shall be included in
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+ * all copies or substantial portions of the Software.
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+ *
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+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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+ * THE SOFTWARE.
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+ */
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+
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+#include <rtthread.h>
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+
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+#ifdef RT_KLIBC_USING_VSNPRINTF_STANDARD
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+
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+#include <stdio.h>
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+#include <stdint.h>
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+#include <limits.h>
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+#include <stdbool.h>
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+
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+// 'ntoa' conversion buffer size, this must be big enough to hold one converted
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+// numeric number including padded zeros (dynamically created on stack)
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+#ifndef RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE
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+#define RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE 32
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+#endif
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+
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+// size of the fixed (on-stack) buffer for printing individual decimal numbers.
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+// this must be big enough to hold one converted floating-point value including
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+// padded zeros.
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+#ifndef RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE
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+#define RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE 32
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+#endif
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+
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+// Support for the decimal notation floating point conversion specifiers (%f, %F)
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+#ifndef RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS
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+#define RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS
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+#endif
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+
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+// Support for the exponential notation floating point conversion specifiers (%e, %g, %E, %G)
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+#ifndef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
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+#define RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
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+#endif
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+
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+// Support for the length write-back specifier (%n)
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+#ifndef RT_KLIBC_USING_VSNPRINTF_WRITEBACK_SPECIFIER
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+#define RT_KLIBC_USING_VSNPRINTF_WRITEBACK_SPECIFIER
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+#endif
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+
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+// Default precision for the floating point conversion specifiers (the C standard sets this at 6)
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+#ifndef RT_KLIBC_USING_VSNPRINTF_FLOAT_PRECISION
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+#define RT_KLIBC_USING_VSNPRINTF_FLOAT_PRECISION 6
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+#endif
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+
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+// According to the C languages standard, printf() and related functions must be able to print any
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+// integral number in floating-point notation, regardless of length, when using the %f specifier -
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+// possibly hundreds of characters, potentially overflowing your buffers. In this implementation,
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+// all values beyond this threshold are switched to exponential notation.
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+#ifndef RT_KLIBC_USING_VSNPRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL
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+#define RT_KLIBC_USING_VSNPRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL 9
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+#endif
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+
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+// Support for the long long integral types (with the ll, z and t length modifiers for specifiers
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+// %d,%i,%o,%x,%X,%u, and with the %p specifier). Note: 'L' (long double) is not supported.
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+#ifndef RT_KLIBC_USING_VSNPRINTF_LONGLONG
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+#define RT_KLIBC_USING_VSNPRINTF_LONGLONG
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+#endif
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+
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+// The number of terms in a Taylor series expansion of log_10(x) to
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+// use for approximation - including the power-zero term (i.e. the
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+// value at the point of expansion).
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+#ifndef RT_KLIBC_USING_VSNPRINTF_LOG10_TAYLOR_TERMS
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+#define RT_KLIBC_USING_VSNPRINTF_LOG10_TAYLOR_TERMS 4
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+#endif
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+
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+// Be extra-safe, and don't assume format specifiers are completed correctly
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+// before the format string end.
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+#if !defined(RT_KLIBC_USING_VSNPRINTF_CHECK_NUL_IN_FORMAT_SPECIFIER) || defined(RT_USING_DEBUG)
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+#define RT_KLIBC_USING_VSNPRINTF_CHECK_NUL_IN_FORMAT_SPECIFIER
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+#endif
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+
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+#if RT_KLIBC_USING_VSNPRINTF_LOG10_TAYLOR_TERMS <= 1
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+#error "At least one non-constant Taylor expansion is necessary for the log10() calculation"
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+#endif
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+
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+///////////////////////////////////////////////////////////////////////////////
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+
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+#define PRINTF_PREFER_DECIMAL false
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+#define PRINTF_PREFER_EXPONENTIAL true
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+
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+// The following will convert the number-of-digits into an exponential-notation literal
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+#define PRINTF_CONCATENATE(s1, s2) s1##s2
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+#define PRINTF_EXPAND_THEN_CONCATENATE(s1, s2) PRINTF_CONCATENATE(s1, s2)
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+#define PRINTF_FLOAT_NOTATION_THRESHOLD PRINTF_EXPAND_THEN_CONCATENATE(1e,RT_KLIBC_USING_VSNPRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL)
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+
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+// internal flag definitions
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+#define FLAGS_ZEROPAD (1U << 0U)
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+#define FLAGS_LEFT (1U << 1U)
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+#define FLAGS_PLUS (1U << 2U)
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+#define FLAGS_SPACE (1U << 3U)
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+#define FLAGS_HASH (1U << 4U)
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+#define FLAGS_UPPERCASE (1U << 5U)
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+#define FLAGS_CHAR (1U << 6U)
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+#define FLAGS_SHORT (1U << 7U)
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+#define FLAGS_INT (1U << 8U)
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+// Only used with RT_KLIBC_USING_VSNPRINTF_MSVC_STYLE_INTEGER_SPECIFIERS
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+#define FLAGS_LONG (1U << 9U)
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+#define FLAGS_LONG_LONG (1U << 10U)
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+#define FLAGS_PRECISION (1U << 11U)
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+#define FLAGS_ADAPT_EXP (1U << 12U)
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+#define FLAGS_POINTER (1U << 13U)
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+// Note: Similar, but not identical, effect as FLAGS_HASH
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+#define FLAGS_SIGNED (1U << 14U)
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+// Only used with RT_KLIBC_USING_VSNPRINTF_MSVC_STYLE_INTEGER_SPECIFIERS
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+
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+#ifdef RT_KLIBC_USING_VSNPRINTF_MSVC_STYLE_INTEGER_SPECIFIERS
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+
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+#define FLAGS_INT8 FLAGS_CHAR
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+
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+#if (SHRT_MAX == 32767LL)
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+#define FLAGS_INT16 FLAGS_SHORT
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+#elif (INT_MAX == 32767LL)
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+#define FLAGS_INT16 FLAGS_INT
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+#elif (LONG_MAX == 32767LL)
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+#define FLAGS_INT16 FLAGS_LONG
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+#elif (LLONG_MAX == 32767LL)
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+#define FLAGS_INT16 FLAGS_LONG_LONG
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+#else
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+#error "No basic integer type has a size of 16 bits exactly"
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+#endif
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+
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+#if (SHRT_MAX == 2147483647LL)
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+#define FLAGS_INT32 FLAGS_SHORT
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+#elif (INT_MAX == 2147483647LL)
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+#define FLAGS_INT32 FLAGS_INT
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+#elif (LONG_MAX == 2147483647LL)
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+#define FLAGS_INT32 FLAGS_LONG
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+#elif (LLONG_MAX == 2147483647LL)
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+#define FLAGS_INT32 FLAGS_LONG_LONG
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+#else
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+#error "No basic integer type has a size of 32 bits exactly"
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+#endif
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+
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+#if (SHRT_MAX == 9223372036854775807LL)
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+#define FLAGS_INT64 FLAGS_SHORT
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+#elif (INT_MAX == 9223372036854775807LL)
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+#define FLAGS_INT64 FLAGS_INT
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+#elif (LONG_MAX == 9223372036854775807LL)
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+#define FLAGS_INT64 FLAGS_LONG
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+#elif (LLONG_MAX == 9223372036854775807LL)
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+#define FLAGS_INT64 FLAGS_LONG_LONG
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+#else
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+#error "No basic integer type has a size of 64 bits exactly"
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+#endif
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+
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+#endif // RT_KLIBC_USING_VSNPRINTF_MSVC_STYLE_INTEGER_SPECIFIERS
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+
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+
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+typedef unsigned int printf_flags_t;
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+
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+#define BASE_BINARY 2
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+#define BASE_OCTAL 8
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+#define BASE_DECIMAL 10
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+#define BASE_HEX 16
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+
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+typedef uint8_t numeric_base_t;
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+
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+#ifdef RT_KLIBC_USING_VSNPRINTF_LONGLONG
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+typedef unsigned long long printf_unsigned_value_t;
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+typedef long long printf_signed_value_t;
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+#else
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+typedef unsigned long printf_unsigned_value_t;
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+typedef long printf_signed_value_t;
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+#endif
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+
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+// The printf()-family functions return an `int`; it is therefore
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+// unnecessary/inappropriate to use size_t - often larger than int
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+// in practice - for non-negative related values, such as widths,
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+// precisions, offsets into buffers used for printing and the sizes
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+// of these buffers. instead, we use:
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+typedef unsigned int printf_size_t;
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+#define PRINTF_MAX_POSSIBLE_BUFFER_SIZE INT_MAX
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+ // If we were to nitpick, this would actually be INT_MAX + 1,
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+ // since INT_MAX is the maximum return value, which excludes the
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+ // trailing '\0'.
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+
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+#if defined(RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS) || defined(RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS)
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+#include <float.h>
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+#if FLT_RADIX != 2
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+#error "Non-binary-radix floating-point types are unsupported."
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+#endif
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+
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+#if DBL_MANT_DIG == 24
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+
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+#define DOUBLE_SIZE_IN_BITS 32
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+typedef uint32_t double_uint_t;
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+#define DOUBLE_EXPONENT_MASK 0xFFU
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+#define DOUBLE_BASE_EXPONENT 127
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+#define DOUBLE_MAX_SUBNORMAL_EXPONENT_OF_10 -38
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+#define DOUBLE_MAX_SUBNORMAL_POWER_OF_10 1e-38
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+
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+#elif DBL_MANT_DIG == 53
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+
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+#define DOUBLE_SIZE_IN_BITS 64
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+typedef uint64_t double_uint_t;
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+#define DOUBLE_EXPONENT_MASK 0x7FFU
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+#define DOUBLE_BASE_EXPONENT 1023
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+#define DOUBLE_MAX_SUBNORMAL_EXPONENT_OF_10 -308
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+#define DOUBLE_MAX_SUBNORMAL_POWER_OF_10 ((double)1e-308L)
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+
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+#else
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+#error "Unsupported double type configuration"
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+#endif
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+#define DOUBLE_STORED_MANTISSA_BITS (DBL_MANT_DIG - 1)
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+
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+typedef union {
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+ double_uint_t U;
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+ double F;
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+} double_with_bit_access;
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+
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+// This is unnecessary in C99, since compound initializers can be used,
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+// but:
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+// 1. Some compilers are finicky about this;
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+// 2. Some people may want to convert this to C89;
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+// 3. If you try to use it as C++, only C++20 supports compound literals
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+static inline double_with_bit_access get_bit_access(double x)
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+{
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+ double_with_bit_access dwba;
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+ dwba.F = x;
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+ return dwba;
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+}
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+
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+static inline int get_sign_bit(double x)
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+{
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+ // The sign is stored in the highest bit
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+ return (int) (get_bit_access(x).U >> (DOUBLE_SIZE_IN_BITS - 1));
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+}
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+
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+static inline int get_exp2(double_with_bit_access x)
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+{
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+ // The exponent in an IEEE-754 floating-point number occupies a contiguous
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+ // sequence of bits (e.g. 52..62 for 64-bit doubles), but with a non-trivial representation: An
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+ // unsigned offset from some negative value (with the extremal offset values reserved for
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+ // special use).
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+ return (int)((x.U >> DOUBLE_STORED_MANTISSA_BITS ) & DOUBLE_EXPONENT_MASK) - DOUBLE_BASE_EXPONENT;
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+}
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+#define PRINTF_ABS(_x) ( (_x) > 0 ? (_x) : -(_x) )
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+
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+#endif // (RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS || RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS)
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+
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+// Note in particular the behavior here on LONG_MIN or LLONG_MIN; it is valid
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+// and well-defined, but if you're not careful you can easily trigger undefined
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+// behavior with -LONG_MIN or -LLONG_MIN
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+#define ABS_FOR_PRINTING(_x) ((printf_unsigned_value_t) ( (_x) > 0 ? (_x) : -((printf_signed_value_t)_x) ))
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+
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+// wrapper (used as buffer) for output function type
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+//
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+// One of the following must hold:
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+// 1. max_chars is 0
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+// 2. buffer is non-null
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+// 3. function is non-null
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+//
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+// ... otherwise bad things will happen.
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+typedef struct {
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+ void (*function)(char c, void* extra_arg);
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+ void* extra_function_arg;
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+ char* buffer;
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+ printf_size_t pos;
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+ printf_size_t max_chars;
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+} output_gadget_t;
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+
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+// Note: This function currently assumes it is not passed a '\0' c,
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+// or alternatively, that '\0' can be passed to the function in the output
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+// gadget. The former assumption holds within the printf library. It also
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+// assumes that the output gadget has been properly initialized.
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+static inline void putchar_via_gadget(output_gadget_t* gadget, char c)
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+{
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+ printf_size_t write_pos = gadget->pos++;
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+ // We're _always_ increasing pos, so as to count how may characters
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+ // _would_ have been written if not for the max_chars limitation
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+ if (write_pos >= gadget->max_chars) {
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+ return;
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+ }
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+ if (gadget->function != NULL) {
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+ // No check for c == '\0' .
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+ gadget->function(c, gadget->extra_function_arg);
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+ }
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+ else {
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+ // it must be the case that gadget->buffer != NULL , due to the constraint
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+ // on output_gadget_t ; and note we're relying on write_pos being non-negative.
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+ gadget->buffer[write_pos] = c;
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+ }
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+}
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+
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+// Possibly-write the string-terminating '\0' character
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+static inline void append_termination_with_gadget(output_gadget_t* gadget)
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+{
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+ if (gadget->function != NULL || gadget->max_chars == 0) {
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+ return;
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+ }
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+ if (gadget->buffer == NULL) {
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+ return;
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+ }
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+ printf_size_t null_char_pos = gadget->pos < gadget->max_chars ? gadget->pos : gadget->max_chars - 1;
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+ gadget->buffer[null_char_pos] = '\0';
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+}
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+
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+static inline output_gadget_t discarding_gadget(void)
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+{
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+ output_gadget_t gadget;
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+ gadget.function = NULL;
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|
|
+ gadget.extra_function_arg = NULL;
|
|
|
+ gadget.buffer = NULL;
|
|
|
+ gadget.pos = 0;
|
|
|
+ gadget.max_chars = 0;
|
|
|
+ return gadget;
|
|
|
+}
|
|
|
+
|
|
|
+static inline output_gadget_t buffer_gadget(char* buffer, size_t buffer_size)
|
|
|
+{
|
|
|
+ printf_size_t usable_buffer_size = (buffer_size > PRINTF_MAX_POSSIBLE_BUFFER_SIZE) ?
|
|
|
+ PRINTF_MAX_POSSIBLE_BUFFER_SIZE : (printf_size_t) buffer_size;
|
|
|
+ output_gadget_t result = discarding_gadget();
|
|
|
+ if (buffer != NULL) {
|
|
|
+ result.buffer = buffer;
|
|
|
+ result.max_chars = usable_buffer_size;
|
|
|
+ }
|
|
|
+ return result;
|
|
|
+}
|
|
|
+
|
|
|
+// internal secure strlen
|
|
|
+// @return The length of the string (excluding the terminating 0) limited by 'maxsize'
|
|
|
+// @note strlen uses size_t, but wes only use this function with printf_size_t
|
|
|
+// variables - hence the signature.
|
|
|
+static inline printf_size_t strnlen_s_(const char* str, printf_size_t maxsize)
|
|
|
+{
|
|
|
+ const char* s;
|
|
|
+ for (s = str; *s && maxsize--; ++s);
|
|
|
+ return (printf_size_t)(s - str);
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+// internal test if char is a digit (0-9)
|
|
|
+// @return true if char is a digit
|
|
|
+static inline bool is_digit_(char ch)
|
|
|
+{
|
|
|
+ return (ch >= '0') && (ch <= '9');
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+// internal ASCII string to printf_size_t conversion
|
|
|
+static printf_size_t atou_(const char** str)
|
|
|
+{
|
|
|
+ printf_size_t i = 0U;
|
|
|
+ while (is_digit_(**str)) {
|
|
|
+ i = i * 10U + (printf_size_t)(*((*str)++) - '0');
|
|
|
+ }
|
|
|
+ return i;
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+// output the specified string in reverse, taking care of any zero-padding
|
|
|
+static void out_rev_(output_gadget_t* output, const char* buf, printf_size_t len, printf_size_t width, printf_flags_t flags)
|
|
|
+{
|
|
|
+ const printf_size_t start_pos = output->pos;
|
|
|
+
|
|
|
+ // pad spaces up to given width
|
|
|
+ if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) {
|
|
|
+ for (printf_size_t i = len; i < width; i++) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // reverse string
|
|
|
+ while (len) {
|
|
|
+ putchar_via_gadget(output, buf[--len]);
|
|
|
+ }
|
|
|
+
|
|
|
+ // append pad spaces up to given width
|
|
|
+ if (flags & FLAGS_LEFT) {
|
|
|
+ while (output->pos - start_pos < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+// Invoked by print_integer after the actual number has been printed, performing necessary
|
|
|
+// work on the number's prefix (as the number is initially printed in reverse order)
|
|
|
+static void print_integer_finalization(output_gadget_t* output, char* buf, printf_size_t len, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags)
|
|
|
+{
|
|
|
+ printf_size_t unpadded_len = len;
|
|
|
+
|
|
|
+ // pad with leading zeros
|
|
|
+ {
|
|
|
+ if (!(flags & FLAGS_LEFT)) {
|
|
|
+ if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
|
|
|
+ width--;
|
|
|
+ }
|
|
|
+ while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ while ((len < precision) && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ }
|
|
|
+
|
|
|
+ if (base == BASE_OCTAL && (len > unpadded_len)) {
|
|
|
+ // Since we've written some zeros, we've satisfied the alternative format leading space requirement
|
|
|
+ flags &= ~FLAGS_HASH;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // handle hash
|
|
|
+ if (flags & (FLAGS_HASH | FLAGS_POINTER)) {
|
|
|
+ if (!(flags & FLAGS_PRECISION) && len && ((len == precision) || (len == width))) {
|
|
|
+ // Let's take back some padding digits to fit in what will eventually
|
|
|
+ // be the format-specific prefix
|
|
|
+ if (unpadded_len < len) {
|
|
|
+ len--; // This should suffice for BASE_OCTAL
|
|
|
+ }
|
|
|
+ if (len && (base == BASE_HEX || base == BASE_BINARY) && (unpadded_len < len)) {
|
|
|
+ len--; // ... and an extra one for 0x or 0b
|
|
|
+ }
|
|
|
+ }
|
|
|
+ if ((base == BASE_HEX) && !(flags & FLAGS_UPPERCASE) && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = 'x';
|
|
|
+ }
|
|
|
+ else if ((base == BASE_HEX) && (flags & FLAGS_UPPERCASE) && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = 'X';
|
|
|
+ }
|
|
|
+ else if ((base == BASE_BINARY) && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = 'b';
|
|
|
+ }
|
|
|
+ if (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ if (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE) {
|
|
|
+ if (negative) {
|
|
|
+ buf[len++] = '-';
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_PLUS) {
|
|
|
+ buf[len++] = '+'; // ignore the space if the '+' exists
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_SPACE) {
|
|
|
+ buf[len++] = ' ';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ out_rev_(output, buf, len, width, flags);
|
|
|
+}
|
|
|
+
|
|
|
+// An internal itoa-like function
|
|
|
+static void print_integer(output_gadget_t* output, printf_unsigned_value_t value, bool negative, numeric_base_t base, printf_size_t precision, printf_size_t width, printf_flags_t flags)
|
|
|
+{
|
|
|
+ char buf[RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE];
|
|
|
+ printf_size_t len = 0U;
|
|
|
+
|
|
|
+ if (!value) {
|
|
|
+ if ( !(flags & FLAGS_PRECISION) ) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ flags &= ~FLAGS_HASH;
|
|
|
+ // We drop this flag this since either the alternative and regular modes of the specifier
|
|
|
+ // don't differ on 0 values, or (in the case of octal) we've already provided the special
|
|
|
+ // handling for this mode.
|
|
|
+ }
|
|
|
+ else if (base == BASE_HEX) {
|
|
|
+ flags &= ~FLAGS_HASH;
|
|
|
+ // We drop this flag this since either the alternative and regular modes of the specifier
|
|
|
+ // don't differ on 0 values
|
|
|
+ }
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ do {
|
|
|
+ const char digit = (char)(value % base);
|
|
|
+ buf[len++] = (char)(digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10);
|
|
|
+ value /= base;
|
|
|
+ } while (value && (len < RT_KLIBC_USING_VSNPRINTF_INTEGER_BUFFER_SIZE));
|
|
|
+ }
|
|
|
+
|
|
|
+ print_integer_finalization(output, buf, len, negative, base, precision, width, flags);
|
|
|
+}
|
|
|
+
|
|
|
+#if defined(RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS) || defined(RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS)
|
|
|
+
|
|
|
+// Stores a fixed-precision representation of a double relative
|
|
|
+// to a fixed precision (which cannot be determined by examining this structure)
|
|
|
+struct double_components {
|
|
|
+ int_fast64_t integral;
|
|
|
+ int_fast64_t fractional;
|
|
|
+ // ... truncation of the actual fractional part of the double value, scaled
|
|
|
+ // by the precision value
|
|
|
+ bool is_negative;
|
|
|
+};
|
|
|
+
|
|
|
+#define NUM_DECIMAL_DIGITS_IN_INT64_T 18
|
|
|
+#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 NUM_DECIMAL_DIGITS_IN_INT64_T
|
|
|
+static const double powers_of_10[NUM_DECIMAL_DIGITS_IN_INT64_T] = {
|
|
|
+ 1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08,
|
|
|
+ 1e09, 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17
|
|
|
+};
|
|
|
+
|
|
|
+#define PRINTF_MAX_SUPPORTED_PRECISION NUM_DECIMAL_DIGITS_IN_INT64_T - 1
|
|
|
+
|
|
|
+
|
|
|
+// Break up a double number - which is known to be a finite non-negative number -
|
|
|
+// into its base-10 parts: integral - before the decimal point, and fractional - after it.
|
|
|
+// Taken the precision into account, but does not change it even internally.
|
|
|
+static struct double_components get_components(double number, printf_size_t precision)
|
|
|
+{
|
|
|
+ struct double_components number_;
|
|
|
+ number_.is_negative = get_sign_bit(number);
|
|
|
+ double abs_number = (number_.is_negative) ? -number : number;
|
|
|
+ number_.integral = (int_fast64_t)abs_number;
|
|
|
+ double remainder = (abs_number - (double) number_.integral) * powers_of_10[precision];
|
|
|
+ number_.fractional = (int_fast64_t)remainder;
|
|
|
+
|
|
|
+ remainder -= (double) number_.fractional;
|
|
|
+
|
|
|
+ if (remainder > 0.5) {
|
|
|
+ ++number_.fractional;
|
|
|
+ // handle rollover, e.g. case 0.99 with precision 1 is 1.0
|
|
|
+ if ((double) number_.fractional >= powers_of_10[precision]) {
|
|
|
+ number_.fractional = 0;
|
|
|
+ ++number_.integral;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ else if ((remainder == 0.5) && ((number_.fractional == 0U) || (number_.fractional & 1U))) {
|
|
|
+ // if halfway, round up if odd OR if last digit is 0
|
|
|
+ ++number_.fractional;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (precision == 0U) {
|
|
|
+ remainder = abs_number - (double) number_.integral;
|
|
|
+ if ((!(remainder < 0.5) || (remainder > 0.5)) && (number_.integral & 1)) {
|
|
|
+ // exactly 0.5 and ODD, then round up
|
|
|
+ // 1.5 -> 2, but 2.5 -> 2
|
|
|
+ ++number_.integral;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return number_;
|
|
|
+}
|
|
|
+
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+struct scaling_factor {
|
|
|
+ double raw_factor;
|
|
|
+ bool multiply; // if true, need to multiply by raw_factor; otherwise need to divide by it
|
|
|
+};
|
|
|
+
|
|
|
+static double apply_scaling(double num, struct scaling_factor normalization)
|
|
|
+{
|
|
|
+ return normalization.multiply ? num * normalization.raw_factor : num / normalization.raw_factor;
|
|
|
+}
|
|
|
+
|
|
|
+static double unapply_scaling(double normalized, struct scaling_factor normalization)
|
|
|
+{
|
|
|
+#if defined(__GNUC__) && !defined(__ARMCC_VERSION) /* GCC */
|
|
|
+// accounting for a static analysis bug in GCC 6.x and earlier
|
|
|
+#pragma GCC diagnostic push
|
|
|
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
|
|
|
+#endif
|
|
|
+ return normalization.multiply ? normalized / normalization.raw_factor : normalized * normalization.raw_factor;
|
|
|
+#if defined(__GNUC__) && !defined(__ARMCC_VERSION) /* GCC */
|
|
|
+#pragma GCC diagnostic pop
|
|
|
+#endif
|
|
|
+}
|
|
|
+
|
|
|
+static struct scaling_factor update_normalization(struct scaling_factor sf, double extra_multiplicative_factor)
|
|
|
+{
|
|
|
+ struct scaling_factor result;
|
|
|
+ if (sf.multiply) {
|
|
|
+ result.multiply = true;
|
|
|
+ result.raw_factor = sf.raw_factor * extra_multiplicative_factor;
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ int factor_exp2 = get_exp2(get_bit_access(sf.raw_factor));
|
|
|
+ int extra_factor_exp2 = get_exp2(get_bit_access(extra_multiplicative_factor));
|
|
|
+
|
|
|
+ // Divide the larger-exponent raw raw_factor by the smaller
|
|
|
+ if (PRINTF_ABS(factor_exp2) > PRINTF_ABS(extra_factor_exp2)) {
|
|
|
+ result.multiply = false;
|
|
|
+ result.raw_factor = sf.raw_factor / extra_multiplicative_factor;
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ result.multiply = true;
|
|
|
+ result.raw_factor = extra_multiplicative_factor / sf.raw_factor;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ return result;
|
|
|
+}
|
|
|
+
|
|
|
+static struct double_components get_normalized_components(bool negative, printf_size_t precision, double non_normalized, struct scaling_factor normalization, int floored_exp10)
|
|
|
+{
|
|
|
+ struct double_components components;
|
|
|
+ components.is_negative = negative;
|
|
|
+ double scaled = apply_scaling(non_normalized, normalization);
|
|
|
+
|
|
|
+ bool close_to_representation_extremum = ( (-floored_exp10 + (int) precision) >= DBL_MAX_10_EXP - 1 );
|
|
|
+ if (close_to_representation_extremum) {
|
|
|
+ // We can't have a normalization factor which also accounts for the precision, i.e. moves
|
|
|
+ // some decimal digits into the mantissa, since it's unrepresentable, or nearly unrepresentable.
|
|
|
+ // So, we'll give up early on getting extra precision...
|
|
|
+ return get_components(negative ? -scaled : scaled, precision);
|
|
|
+ }
|
|
|
+ components.integral = (int_fast64_t) scaled;
|
|
|
+ double remainder = non_normalized - unapply_scaling((double) components.integral, normalization);
|
|
|
+ double prec_power_of_10 = powers_of_10[precision];
|
|
|
+ struct scaling_factor account_for_precision = update_normalization(normalization, prec_power_of_10);
|
|
|
+ double scaled_remainder = apply_scaling(remainder, account_for_precision);
|
|
|
+ double rounding_threshold = 0.5;
|
|
|
+
|
|
|
+ components.fractional = (int_fast64_t) scaled_remainder; // when precision == 0, the assigned value should be 0
|
|
|
+ scaled_remainder -= (double) components.fractional; //when precision == 0, this will not change scaled_remainder
|
|
|
+
|
|
|
+ components.fractional += (scaled_remainder >= rounding_threshold);
|
|
|
+ if (scaled_remainder == rounding_threshold) {
|
|
|
+ // banker's rounding: Round towards the even number (making the mean error 0)
|
|
|
+ components.fractional &= ~((int_fast64_t) 0x1);
|
|
|
+ }
|
|
|
+ // handle rollover, e.g. the case of 0.99 with precision 1 becoming (0,100),
|
|
|
+ // and must then be corrected into (1, 0).
|
|
|
+ // Note: for precision = 0, this will "translate" the rounding effect from
|
|
|
+ // the fractional part to the integral part where it should actually be
|
|
|
+ // felt (as prec_power_of_10 is 1)
|
|
|
+ if ((double) components.fractional >= prec_power_of_10) {
|
|
|
+ components.fractional = 0;
|
|
|
+ ++components.integral;
|
|
|
+ }
|
|
|
+ return components;
|
|
|
+}
|
|
|
+#endif // RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+
|
|
|
+static void print_broken_up_decimal(
|
|
|
+ struct double_components number_, output_gadget_t* output, printf_size_t precision,
|
|
|
+ printf_size_t width, printf_flags_t flags, char *buf, printf_size_t len)
|
|
|
+{
|
|
|
+ if (precision != 0U) {
|
|
|
+ // do fractional part, as an unsigned number
|
|
|
+
|
|
|
+ printf_size_t count = precision;
|
|
|
+
|
|
|
+ // %g/%G mandates we skip the trailing 0 digits...
|
|
|
+ if ((flags & FLAGS_ADAPT_EXP) && !(flags & FLAGS_HASH) && (number_.fractional > 0)) {
|
|
|
+ while(true) {
|
|
|
+ int_fast64_t digit = number_.fractional % 10U;
|
|
|
+ if (digit != 0) {
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ --count;
|
|
|
+ number_.fractional /= 10U;
|
|
|
+
|
|
|
+ }
|
|
|
+ // ... and even the decimal point if there are no
|
|
|
+ // non-zero fractional part digits (see below)
|
|
|
+ }
|
|
|
+
|
|
|
+ if (number_.fractional > 0 || !(flags & FLAGS_ADAPT_EXP) || (flags & FLAGS_HASH) ) {
|
|
|
+ while (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) {
|
|
|
+ --count;
|
|
|
+ buf[len++] = (char)('0' + number_.fractional % 10U);
|
|
|
+ if (!(number_.fractional /= 10U)) {
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // add extra 0s
|
|
|
+ while ((len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) && (count > 0U)) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ --count;
|
|
|
+ }
|
|
|
+ if (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) {
|
|
|
+ buf[len++] = '.';
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ if ((flags & FLAGS_HASH) && (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = '.';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // Write the integer part of the number (it comes after the fractional
|
|
|
+ // since the character order is reversed)
|
|
|
+ while (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) {
|
|
|
+ buf[len++] = (char)('0' + (number_.integral % 10));
|
|
|
+ if (!(number_.integral /= 10)) {
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // pad leading zeros
|
|
|
+ if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) {
|
|
|
+ if (width && (number_.is_negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
|
|
|
+ width--;
|
|
|
+ }
|
|
|
+ while ((len < width) && (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE)) {
|
|
|
+ buf[len++] = '0';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ if (len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) {
|
|
|
+ if (number_.is_negative) {
|
|
|
+ buf[len++] = '-';
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_PLUS) {
|
|
|
+ buf[len++] = '+'; // ignore the space if the '+' exists
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_SPACE) {
|
|
|
+ buf[len++] = ' ';
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ out_rev_(output, buf, len, width, flags);
|
|
|
+}
|
|
|
+
|
|
|
+ // internal ftoa for fixed decimal floating point
|
|
|
+static void print_decimal_number(output_gadget_t* output, double number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len)
|
|
|
+{
|
|
|
+ struct double_components value_ = get_components(number, precision);
|
|
|
+ print_broken_up_decimal(value_, output, precision, width, flags, buf, len);
|
|
|
+}
|
|
|
+
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+
|
|
|
+// A floor function - but one which only works for numbers whose
|
|
|
+// floor value is representable by an int.
|
|
|
+static int bastardized_floor(double x)
|
|
|
+{
|
|
|
+ if (x >= 0) { return (int) x; }
|
|
|
+ int n = (int) x;
|
|
|
+ return ( ((double) n) == x ) ? n : n-1;
|
|
|
+}
|
|
|
+
|
|
|
+// Computes the base-10 logarithm of the input number - which must be an actual
|
|
|
+// positive number (not infinity or NaN, nor a sub-normal)
|
|
|
+static double log10_of_positive(double positive_number)
|
|
|
+{
|
|
|
+ // The implementation follows David Gay (https://www.ampl.com/netlib/fp/dtoa.c).
|
|
|
+ //
|
|
|
+ // Since log_10 ( M * 2^x ) = log_10(M) + x , we can separate the components of
|
|
|
+ // our input number, and need only solve log_10(M) for M between 1 and 2 (as
|
|
|
+ // the base-2 mantissa is always 1-point-something). In that limited range, a
|
|
|
+ // Taylor series expansion of log10(x) should serve us well enough; and we'll
|
|
|
+ // take the mid-point, 1.5, as the point of expansion.
|
|
|
+
|
|
|
+ double_with_bit_access dwba = get_bit_access(positive_number);
|
|
|
+ // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c)
|
|
|
+ int exp2 = get_exp2(dwba);
|
|
|
+ // drop the exponent, so dwba.F comes into the range [1,2)
|
|
|
+ dwba.U = (dwba.U & (((double_uint_t) (1) << DOUBLE_STORED_MANTISSA_BITS) - 1U)) |
|
|
|
+ ((double_uint_t) DOUBLE_BASE_EXPONENT << DOUBLE_STORED_MANTISSA_BITS);
|
|
|
+ double z = (dwba.F - 1.5);
|
|
|
+ return (
|
|
|
+ // Taylor expansion around 1.5:
|
|
|
+ 0.1760912590556812420 // Expansion term 0: ln(1.5) / ln(10)
|
|
|
+ + z * 0.2895296546021678851 // Expansion term 1: (M - 1.5) * 2/3 / ln(10)
|
|
|
+#if RT_KLIBC_USING_VSNPRINTF_LOG10_TAYLOR_TERMS > 2
|
|
|
+ - z*z * 0.0965098848673892950 // Expansion term 2: (M - 1.5)^2 * 2/9 / ln(10)
|
|
|
+#if RT_KLIBC_USING_VSNPRINTF_LOG10_TAYLOR_TERMS > 3
|
|
|
+ + z*z*z * 0.0428932821632841311 // Expansion term 2: (M - 1.5)^3 * 8/81 / ln(10)
|
|
|
+#endif
|
|
|
+#endif
|
|
|
+ // exact log_2 of the exponent x, with logarithm base change
|
|
|
+ + exp2 * 0.30102999566398119521 // = exp2 * log_10(2) = exp2 * ln(2)/ln(10)
|
|
|
+ );
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+static double pow10_of_int(int floored_exp10)
|
|
|
+{
|
|
|
+ // A crude hack for avoiding undesired behavior with barely-normal or slightly-subnormal values.
|
|
|
+ if (floored_exp10 == DOUBLE_MAX_SUBNORMAL_EXPONENT_OF_10) {
|
|
|
+ return DOUBLE_MAX_SUBNORMAL_POWER_OF_10;
|
|
|
+ }
|
|
|
+ // Compute 10^(floored_exp10) but (try to) make sure that doesn't overflow
|
|
|
+ double_with_bit_access dwba;
|
|
|
+ int exp2 = bastardized_floor(floored_exp10 * 3.321928094887362 + 0.5);
|
|
|
+ const double z = floored_exp10 * 2.302585092994046 - exp2 * 0.6931471805599453;
|
|
|
+ const double z2 = z * z;
|
|
|
+ dwba.U = ((double_uint_t)(exp2) + DOUBLE_BASE_EXPONENT) << DOUBLE_STORED_MANTISSA_BITS;
|
|
|
+ // compute exp(z) using continued fractions,
|
|
|
+ // see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
|
|
|
+ dwba.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
|
|
|
+ return dwba.F;
|
|
|
+}
|
|
|
+
|
|
|
+static void print_exponential_number(output_gadget_t* output, double number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len)
|
|
|
+{
|
|
|
+ const bool negative = get_sign_bit(number);
|
|
|
+ // This number will decrease gradually (by factors of 10) as we "extract" the exponent out of it
|
|
|
+ double abs_number = negative ? -number : number;
|
|
|
+
|
|
|
+ int floored_exp10;
|
|
|
+ bool abs_exp10_covered_by_powers_table;
|
|
|
+ struct scaling_factor normalization;
|
|
|
+
|
|
|
+
|
|
|
+ // Determine the decimal exponent
|
|
|
+ if (abs_number == 0.0) {
|
|
|
+ // TODO: This is a special-case for 0.0 (and -0.0); but proper handling is required for denormals more generally.
|
|
|
+ floored_exp10 = 0; // ... and no need to set a normalization factor or check the powers table
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ double exp10 = log10_of_positive(abs_number);
|
|
|
+ floored_exp10 = bastardized_floor(exp10);
|
|
|
+ double p10 = pow10_of_int(floored_exp10);
|
|
|
+ // correct for rounding errors
|
|
|
+ if (abs_number < p10) {
|
|
|
+ floored_exp10--;
|
|
|
+ p10 /= 10;
|
|
|
+ }
|
|
|
+ abs_exp10_covered_by_powers_table = PRINTF_ABS(floored_exp10) < PRINTF_MAX_PRECOMPUTED_POWER_OF_10;
|
|
|
+ normalization.raw_factor = abs_exp10_covered_by_powers_table ? powers_of_10[PRINTF_ABS(floored_exp10)] : p10;
|
|
|
+ }
|
|
|
+
|
|
|
+ // We now begin accounting for the widths of the two parts of our printed field:
|
|
|
+ // the decimal part after decimal exponent extraction, and the base-10 exponent part.
|
|
|
+ // For both of these, the value of 0 has a special meaning, but not the same one:
|
|
|
+ // a 0 exponent-part width means "don't print the exponent"; a 0 decimal-part width
|
|
|
+ // means "use as many characters as necessary".
|
|
|
+
|
|
|
+ bool fall_back_to_decimal_only_mode = false;
|
|
|
+ if (flags & FLAGS_ADAPT_EXP) {
|
|
|
+ int required_significant_digits = (precision == 0) ? 1 : (int) precision;
|
|
|
+ // Should we want to fall-back to "%f" mode, and only print the decimal part?
|
|
|
+ fall_back_to_decimal_only_mode = (floored_exp10 >= -4 && floored_exp10 < required_significant_digits);
|
|
|
+ // Now, let's adjust the precision
|
|
|
+ // This also decided how we adjust the precision value - as in "%g" mode,
|
|
|
+ // "precision" is the number of _significant digits_, and this is when we "translate"
|
|
|
+ // the precision value to an actual number of decimal digits.
|
|
|
+ int precision_ = fall_back_to_decimal_only_mode ?
|
|
|
+ (int) precision - 1 - floored_exp10 :
|
|
|
+ (int) precision - 1; // the presence of the exponent ensures only one significant digit comes before the decimal point
|
|
|
+ precision = (precision_ > 0 ? (unsigned) precision_ : 0U);
|
|
|
+ flags |= FLAGS_PRECISION; // make sure print_broken_up_decimal respects our choice above
|
|
|
+ }
|
|
|
+
|
|
|
+ normalization.multiply = (floored_exp10 < 0 && abs_exp10_covered_by_powers_table);
|
|
|
+ bool should_skip_normalization = (fall_back_to_decimal_only_mode || floored_exp10 == 0);
|
|
|
+ struct double_components decimal_part_components =
|
|
|
+ should_skip_normalization ?
|
|
|
+ get_components(negative ? -abs_number : abs_number, precision) :
|
|
|
+ get_normalized_components(negative, precision, abs_number, normalization, floored_exp10);
|
|
|
+
|
|
|
+ // Account for roll-over, e.g. rounding from 9.99 to 100.0 - which effects
|
|
|
+ // the exponent and may require additional tweaking of the parts
|
|
|
+ if (fall_back_to_decimal_only_mode) {
|
|
|
+ if ((flags & FLAGS_ADAPT_EXP) && floored_exp10 >= -1 && decimal_part_components.integral == powers_of_10[floored_exp10 + 1]) {
|
|
|
+ floored_exp10++; // Not strictly necessary, since floored_exp10 is no longer really used
|
|
|
+ precision--;
|
|
|
+ // ... and it should already be the case that decimal_part_components.fractional == 0
|
|
|
+ }
|
|
|
+ // TODO: What about rollover strictly within the fractional part?
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ if (decimal_part_components.integral >= 10) {
|
|
|
+ floored_exp10++;
|
|
|
+ decimal_part_components.integral = 1;
|
|
|
+ decimal_part_components.fractional = 0;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // the floored_exp10 format is "E%+03d" and largest possible floored_exp10 value for a 64-bit double
|
|
|
+ // is "307" (for 2^1023), so we set aside 4-5 characters overall
|
|
|
+ printf_size_t exp10_part_width = fall_back_to_decimal_only_mode ? 0U : (PRINTF_ABS(floored_exp10) < 100) ? 4U : 5U;
|
|
|
+
|
|
|
+ printf_size_t decimal_part_width =
|
|
|
+ ((flags & FLAGS_LEFT) && exp10_part_width) ?
|
|
|
+ // We're padding on the right, so the width constraint is the exponent part's
|
|
|
+ // problem, not the decimal part's, so we'll use as many characters as we need:
|
|
|
+ 0U :
|
|
|
+ // We're padding on the left; so the width constraint is the decimal part's
|
|
|
+ // problem. Well, can both the decimal part and the exponent part fit within our overall width?
|
|
|
+ ((width > exp10_part_width) ?
|
|
|
+ // Yes, so we limit our decimal part's width.
|
|
|
+ // (Note this is trivially valid even if we've fallen back to "%f" mode)
|
|
|
+ width - exp10_part_width :
|
|
|
+ // No; we just give up on any restriction on the decimal part and use as many
|
|
|
+ // characters as we need
|
|
|
+ 0U);
|
|
|
+
|
|
|
+ const printf_size_t printed_exponential_start_pos = output->pos;
|
|
|
+ print_broken_up_decimal(decimal_part_components, output, precision, decimal_part_width, flags, buf, len);
|
|
|
+
|
|
|
+ if (! fall_back_to_decimal_only_mode) {
|
|
|
+ putchar_via_gadget(output, (flags & FLAGS_UPPERCASE) ? 'E' : 'e');
|
|
|
+ print_integer(output,
|
|
|
+ ABS_FOR_PRINTING(floored_exp10),
|
|
|
+ floored_exp10 < 0, 10, 0, exp10_part_width - 1,
|
|
|
+ FLAGS_ZEROPAD | FLAGS_PLUS);
|
|
|
+ if (flags & FLAGS_LEFT) {
|
|
|
+ // We need to right-pad with spaces to meet the width requirement
|
|
|
+ while (output->pos - printed_exponential_start_pos < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+#endif // RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+
|
|
|
+static void print_floating_point(output_gadget_t* output, double value, printf_size_t precision, printf_size_t width, printf_flags_t flags, bool prefer_exponential)
|
|
|
+{
|
|
|
+ char buf[RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE];
|
|
|
+ printf_size_t len = 0U;
|
|
|
+
|
|
|
+ // test for special values
|
|
|
+ if (value != value) {
|
|
|
+ out_rev_(output, "nan", 3, width, flags);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ if (value < -DBL_MAX) {
|
|
|
+ out_rev_(output, "fni-", 4, width, flags);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ if (value > DBL_MAX) {
|
|
|
+ out_rev_(output, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags);
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (!prefer_exponential &&
|
|
|
+ ((value > PRINTF_FLOAT_NOTATION_THRESHOLD) || (value < -PRINTF_FLOAT_NOTATION_THRESHOLD))) {
|
|
|
+ // The required behavior of standard printf is to print _every_ integral-part digit -- which could mean
|
|
|
+ // printing hundreds of characters, overflowing any fixed internal buffer and necessitating a more complicated
|
|
|
+ // implementation.
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+ print_exponential_number(output, value, precision, width, flags, buf, len);
|
|
|
+#endif
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ // set default precision, if not set explicitly
|
|
|
+ if (!(flags & FLAGS_PRECISION)) {
|
|
|
+ precision = RT_KLIBC_USING_VSNPRINTF_FLOAT_PRECISION;
|
|
|
+ }
|
|
|
+
|
|
|
+ // limit precision so that our integer holding the fractional part does not overflow
|
|
|
+ while ((len < RT_KLIBC_USING_VSNPRINTF_DECIMAL_BUFFER_SIZE) && (precision > PRINTF_MAX_SUPPORTED_PRECISION)) {
|
|
|
+ buf[len++] = '0'; // This respects the precision in terms of result length only
|
|
|
+ precision--;
|
|
|
+ }
|
|
|
+
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+ if (prefer_exponential)
|
|
|
+ print_exponential_number(output, value, precision, width, flags, buf, len);
|
|
|
+ else
|
|
|
+#endif
|
|
|
+ print_decimal_number(output, value, precision, width, flags, buf, len);
|
|
|
+}
|
|
|
+
|
|
|
+#endif // (RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS || RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS)
|
|
|
+
|
|
|
+// Advances the format pointer past the flags, and returns the parsed flags
|
|
|
+// due to the characters passed
|
|
|
+static printf_flags_t parse_flags(const char** format)
|
|
|
+{
|
|
|
+ printf_flags_t flags = 0U;
|
|
|
+ do {
|
|
|
+ switch (**format) {
|
|
|
+ case '0': flags |= FLAGS_ZEROPAD; (*format)++; break;
|
|
|
+ case '-': flags |= FLAGS_LEFT; (*format)++; break;
|
|
|
+ case '+': flags |= FLAGS_PLUS; (*format)++; break;
|
|
|
+ case ' ': flags |= FLAGS_SPACE; (*format)++; break;
|
|
|
+ case '#': flags |= FLAGS_HASH; (*format)++; break;
|
|
|
+ default : return flags;
|
|
|
+ }
|
|
|
+ } while (true);
|
|
|
+}
|
|
|
+
|
|
|
+static inline void format_string_loop(output_gadget_t* output, const char* format, va_list args)
|
|
|
+{
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_CHECK_NUL_IN_FORMAT_SPECIFIER
|
|
|
+#define ADVANCE_IN_FORMAT_STRING(cptr_) do { (cptr_)++; if (!*(cptr_)) return; } while(0)
|
|
|
+#else
|
|
|
+#define ADVANCE_IN_FORMAT_STRING(cptr_) (cptr_)++
|
|
|
+#endif
|
|
|
+
|
|
|
+
|
|
|
+ while (*format)
|
|
|
+ {
|
|
|
+ if (*format != '%') {
|
|
|
+ // A regular content character
|
|
|
+ putchar_via_gadget(output, *format);
|
|
|
+ format++;
|
|
|
+ continue;
|
|
|
+ }
|
|
|
+ // We're parsing a format specifier: %[flags][width][.precision][length]
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+
|
|
|
+ printf_flags_t flags = parse_flags(&format);
|
|
|
+
|
|
|
+ // evaluate width field
|
|
|
+ printf_size_t width = 0U;
|
|
|
+ if (is_digit_(*format)) {
|
|
|
+ width = (printf_size_t) atou_(&format);
|
|
|
+ }
|
|
|
+ else if (*format == '*') {
|
|
|
+ const int w = va_arg(args, int);
|
|
|
+ if (w < 0) {
|
|
|
+ flags |= FLAGS_LEFT; // reverse padding
|
|
|
+ width = (printf_size_t)-w;
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ width = (printf_size_t)w;
|
|
|
+ }
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ }
|
|
|
+
|
|
|
+ // evaluate precision field
|
|
|
+ printf_size_t precision = 0U;
|
|
|
+ if (*format == '.') {
|
|
|
+ flags |= FLAGS_PRECISION;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (is_digit_(*format)) {
|
|
|
+ precision = (printf_size_t) atou_(&format);
|
|
|
+ }
|
|
|
+ else if (*format == '*') {
|
|
|
+ const int precision_ = va_arg(args, int);
|
|
|
+ precision = precision_ > 0 ? (printf_size_t) precision_ : 0U;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ // evaluate length field
|
|
|
+ switch (*format) {
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_MSVC_STYLE_INTEGER_SPECIFIERS
|
|
|
+ case 'I' : {
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ // Greedily parse for size in bits: 8, 16, 32 or 64
|
|
|
+ switch(*format) {
|
|
|
+ case '8': flags |= FLAGS_INT8;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ break;
|
|
|
+ case '1':
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (*format == '6') { format++; flags |= FLAGS_INT16; }
|
|
|
+ break;
|
|
|
+ case '3':
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (*format == '2') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT32; }
|
|
|
+ break;
|
|
|
+ case '6':
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (*format == '4') { ADVANCE_IN_FORMAT_STRING(format); flags |= FLAGS_INT64; }
|
|
|
+ break;
|
|
|
+ default: break;
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ }
|
|
|
+#endif
|
|
|
+ case 'l' :
|
|
|
+ flags |= FLAGS_LONG;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (*format == 'l') {
|
|
|
+ flags |= FLAGS_LONG_LONG;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ case 'h' :
|
|
|
+ flags |= FLAGS_SHORT;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ if (*format == 'h') {
|
|
|
+ flags |= FLAGS_CHAR;
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ case 't' :
|
|
|
+ flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ break;
|
|
|
+ case 'j' :
|
|
|
+ flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ break;
|
|
|
+ case 'z' :
|
|
|
+ flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
|
|
|
+ ADVANCE_IN_FORMAT_STRING(format);
|
|
|
+ break;
|
|
|
+ default:
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ // evaluate specifier
|
|
|
+ switch (*format) {
|
|
|
+ case 'd' :
|
|
|
+ case 'i' :
|
|
|
+ case 'u' :
|
|
|
+ case 'x' :
|
|
|
+ case 'X' :
|
|
|
+ case 'o' :
|
|
|
+ case 'b' : {
|
|
|
+
|
|
|
+ if (*format == 'd' || *format == 'i') {
|
|
|
+ flags |= FLAGS_SIGNED;
|
|
|
+ }
|
|
|
+
|
|
|
+ numeric_base_t base;
|
|
|
+ if (*format == 'x' || *format == 'X') {
|
|
|
+ base = BASE_HEX;
|
|
|
+ }
|
|
|
+ else if (*format == 'o') {
|
|
|
+ base = BASE_OCTAL;
|
|
|
+ }
|
|
|
+ else if (*format == 'b') {
|
|
|
+ base = BASE_BINARY;
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ base = BASE_DECIMAL;
|
|
|
+ flags &= ~FLAGS_HASH; // decimal integers have no alternative presentation
|
|
|
+ }
|
|
|
+
|
|
|
+ if (*format == 'X') {
|
|
|
+ flags |= FLAGS_UPPERCASE;
|
|
|
+ }
|
|
|
+
|
|
|
+ format++;
|
|
|
+ // ignore '0' flag when precision is given
|
|
|
+ if (flags & FLAGS_PRECISION) {
|
|
|
+ flags &= ~FLAGS_ZEROPAD;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (flags & FLAGS_SIGNED) {
|
|
|
+ // A signed specifier: d, i or possibly I + bit size if enabled
|
|
|
+
|
|
|
+ if (flags & FLAGS_LONG_LONG) {
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_LONGLONG
|
|
|
+ const long long value = va_arg(args, long long);
|
|
|
+ print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags);
|
|
|
+#endif
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_LONG) {
|
|
|
+ const long value = va_arg(args, long);
|
|
|
+ print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags);
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ // We never try to interpret the argument as something potentially-smaller than int,
|
|
|
+ // due to integer promotion rules: Even if the user passed a short int, short unsigned
|
|
|
+ // etc. - these will come in after promotion, as int's (or unsigned for the case of
|
|
|
+ // short unsigned when it has the same size as int)
|
|
|
+ const int value =
|
|
|
+ (flags & FLAGS_CHAR) ? (signed char) va_arg(args, int) :
|
|
|
+ (flags & FLAGS_SHORT) ? (short int) va_arg(args, int) :
|
|
|
+ va_arg(args, int);
|
|
|
+ print_integer(output, ABS_FOR_PRINTING(value), value < 0, base, precision, width, flags);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ // An unsigned specifier: u, x, X, o, b
|
|
|
+
|
|
|
+ flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
|
|
|
+
|
|
|
+ if (flags & FLAGS_LONG_LONG) {
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_LONGLONG
|
|
|
+ print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long long), false, base, precision, width, flags);
|
|
|
+#endif
|
|
|
+ }
|
|
|
+ else if (flags & FLAGS_LONG) {
|
|
|
+ print_integer(output, (printf_unsigned_value_t) va_arg(args, unsigned long), false, base, precision, width, flags);
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ const unsigned int value =
|
|
|
+ (flags & FLAGS_CHAR) ? (unsigned char)va_arg(args, unsigned int) :
|
|
|
+ (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(args, unsigned int) :
|
|
|
+ va_arg(args, unsigned int);
|
|
|
+ print_integer(output, (printf_unsigned_value_t) value, false, base, precision, width, flags);
|
|
|
+ }
|
|
|
+ }
|
|
|
+ break;
|
|
|
+ }
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_DECIMAL_SPECIFIERS
|
|
|
+ case 'f' :
|
|
|
+ case 'F' :
|
|
|
+ if (*format == 'F') flags |= FLAGS_UPPERCASE;
|
|
|
+ print_floating_point(output, va_arg(args, double), precision, width, flags, PRINTF_PREFER_DECIMAL);
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+#endif
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+ case 'e':
|
|
|
+ case 'E':
|
|
|
+ case 'g':
|
|
|
+ case 'G':
|
|
|
+ if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP;
|
|
|
+ if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE;
|
|
|
+ print_floating_point(output, va_arg(args, double), precision, width, flags, PRINTF_PREFER_EXPONENTIAL);
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+#endif // RT_KLIBC_USING_VSNPRINTF_EXPONENTIAL_SPECIFIERS
|
|
|
+ case 'c' : {
|
|
|
+ printf_size_t l = 1U;
|
|
|
+ // pre padding
|
|
|
+ if (!(flags & FLAGS_LEFT)) {
|
|
|
+ while (l++ < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // char output
|
|
|
+ putchar_via_gadget(output, (char) va_arg(args, int) );
|
|
|
+ // post padding
|
|
|
+ if (flags & FLAGS_LEFT) {
|
|
|
+ while (l++ < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ case 's' : {
|
|
|
+ const char* p = va_arg(args, char*);
|
|
|
+ if (p == NULL) {
|
|
|
+ out_rev_(output, ")llun(", 6, width, flags);
|
|
|
+ }
|
|
|
+ else {
|
|
|
+ printf_size_t l = strnlen_s_(p, precision ? precision : PRINTF_MAX_POSSIBLE_BUFFER_SIZE);
|
|
|
+ // pre padding
|
|
|
+ if (flags & FLAGS_PRECISION) {
|
|
|
+ l = (l < precision ? l : precision);
|
|
|
+ }
|
|
|
+ if (!(flags & FLAGS_LEFT)) {
|
|
|
+ while (l++ < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+ // string output
|
|
|
+ while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision)) {
|
|
|
+ putchar_via_gadget(output, *(p++));
|
|
|
+ --precision;
|
|
|
+ }
|
|
|
+ // post padding
|
|
|
+ if (flags & FLAGS_LEFT) {
|
|
|
+ while (l++ < width) {
|
|
|
+ putchar_via_gadget(output, ' ');
|
|
|
+ }
|
|
|
+ }
|
|
|
+ }
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ case 'p' : {
|
|
|
+ width = sizeof(void*) * 2U + 2; // 2 hex chars per byte + the "0x" prefix
|
|
|
+ flags |= FLAGS_ZEROPAD | FLAGS_POINTER;
|
|
|
+ uintptr_t value = (uintptr_t)va_arg(args, void*);
|
|
|
+ (value == (uintptr_t) NULL) ?
|
|
|
+ out_rev_(output, ")lin(", 5, width, flags) :
|
|
|
+ print_integer(output, (printf_unsigned_value_t) value, false, BASE_HEX, precision, width, flags);
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+
|
|
|
+ case '%' :
|
|
|
+ putchar_via_gadget(output, '%');
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+
|
|
|
+ // Many people prefer to disable support for %n, as it lets the caller
|
|
|
+ // engineer a write to an arbitrary location, of a value the caller
|
|
|
+ // effectively controls - which could be a security concern in some cases.
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_WRITEBACK_SPECIFIER
|
|
|
+ case 'n' : {
|
|
|
+ if (flags & FLAGS_CHAR) *(va_arg(args, char*)) = (char) output->pos;
|
|
|
+ else if (flags & FLAGS_SHORT) *(va_arg(args, short*)) = (short) output->pos;
|
|
|
+ else if (flags & FLAGS_LONG) *(va_arg(args, long*)) = (long) output->pos;
|
|
|
+#ifdef RT_KLIBC_USING_VSNPRINTF_LONGLONG
|
|
|
+ else if (flags & FLAGS_LONG_LONG) *(va_arg(args, long long*)) = (long long int) output->pos;
|
|
|
+#endif // RT_KLIBC_USING_VSNPRINTF_LONGLONG
|
|
|
+ else *(va_arg(args, int*)) = (int) output->pos;
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+#endif // RT_KLIBC_USING_VSNPRINTF_WRITEBACK_SPECIFIER
|
|
|
+
|
|
|
+ default :
|
|
|
+ putchar_via_gadget(output, *format);
|
|
|
+ format++;
|
|
|
+ break;
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// internal vsnprintf - used for implementing _all library functions
|
|
|
+static int vsnprintf_impl(output_gadget_t* output, const char* format, va_list args)
|
|
|
+{
|
|
|
+ // Note: The library only calls vsnprintf_impl() with output->pos being 0. However, it is
|
|
|
+ // possible to call this function with a non-zero pos value for some "remedial printing".
|
|
|
+ format_string_loop(output, format, args);
|
|
|
+
|
|
|
+ // termination
|
|
|
+ append_termination_with_gadget(output);
|
|
|
+
|
|
|
+ // return written chars without terminating \0
|
|
|
+ return (int)output->pos;
|
|
|
+}
|
|
|
+
|
|
|
+///////////////////////////////////////////////////////////////////////////////
|
|
|
+
|
|
|
+/**
|
|
|
+ * @brief This function will fill a formatted string to buffer.
|
|
|
+ *
|
|
|
+ * @param buf is the buffer to save formatted string.
|
|
|
+ *
|
|
|
+ * @param size is the size of buffer.
|
|
|
+ *
|
|
|
+ * @param fmt is the format parameters.
|
|
|
+ *
|
|
|
+ * @param args is a list of variable parameters.
|
|
|
+ *
|
|
|
+ * @return The number of characters actually written to buffer.
|
|
|
+ */
|
|
|
+int rt_vsnprintf(char *buf, rt_size_t size, const char *fmt, va_list args)
|
|
|
+{
|
|
|
+ output_gadget_t gadget = buffer_gadget(buf, size);
|
|
|
+ return vsnprintf_impl(&gadget, fmt, args);
|
|
|
+}
|
|
|
+
|
|
|
+#endif /* RT_KLIBC_USING_VSNPRINTF_STANDARD */
|
Meco Man