diff --git a/kernel/Makefile b/kernel/Makefile index c085fa6..e437f76 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -5,10 +5,12 @@ ldflags := cflags := buildtype ?= release -include $(platform)/src.mk include $(platform)/flags.mk include generic/flags.mk +include $(platform)/src.mk +include libk/src.mk + all: build/kernel.elf build/kernel.elf: $(o) diff --git a/kernel/amd64/bootmain.c b/kernel/amd64/bootmain.c index eace362..9fb423a 100644 --- a/kernel/amd64/bootmain.c +++ b/kernel/amd64/bootmain.c @@ -1,5 +1,11 @@ #include +#include +#include void bootmain(void) { + amd64_init(); + + DEBUG("Hello from amd64!\n"); + for (;;); } diff --git a/kernel/amd64/debug.c b/kernel/amd64/debug.c new file mode 100644 index 0000000..d45692c --- /dev/null +++ b/kernel/amd64/debug.c @@ -0,0 +1,46 @@ +#include +#include +#include +#include +#include +#include + +#define PORT_COM1 0x03F8 +#define BUFFER_SIZE 1024 + +static bool amd64_debug_serial_tx_empty(void) { + return (bool)(amd64_io_inb(PORT_COM1 + 5) & 0x20); +} + +static void amd64_debug_serial_write(char x) { + while (!amd64_debug_serial_tx_empty()); + amd64_io_outb(PORT_COM1, (uint8_t)x); +} + +void debugprintf(const char *fmt, ...) { + char buffer[BUFFER_SIZE]; + memset(buffer, 0, sizeof(buffer)); + + va_list ap; + va_start(ap, fmt); + vsnprintf(buffer, sizeof(buffer), fmt, ap); + va_end(ap); + + buffer[sizeof(buffer) - 1] = '\0'; + + const char *p = buffer; + while (*p) { + amd64_debug_serial_write(*p); + p++; + } +} + +void amd64_debug_init(void) { + amd64_io_outb(PORT_COM1 + 1, 0x00); + amd64_io_outb(PORT_COM1 + 3, 0x80); + amd64_io_outb(PORT_COM1 + 0, 0x03); + amd64_io_outb(PORT_COM1 + 1, 0x00); + amd64_io_outb(PORT_COM1 + 3, 0x03); + amd64_io_outb(PORT_COM1 + 2, 0xC7); + amd64_io_outb(PORT_COM1 + 4, 0x0B); +} diff --git a/kernel/amd64/debug.h b/kernel/amd64/debug.h new file mode 100644 index 0000000..4f2bcf8 --- /dev/null +++ b/kernel/amd64/debug.h @@ -0,0 +1,6 @@ +#ifndef _KERNEL_AMD64_DEBUG_H +#define _KERNEL_AMD64_DEBUG_H + +void amd64_debug_init(void); + +#endif // _KERNEL_AMD64_DEBUG_H diff --git a/kernel/amd64/flags.mk b/kernel/amd64/flags.mk index 71e3de7..62b72cb 100644 --- a/kernel/amd64/flags.mk +++ b/kernel/amd64/flags.mk @@ -1,3 +1,4 @@ cflags += --target=x86_64-pc-none-elf -ldflags += --target=x86_64-pc-none-elf +ldflags += --target=x86_64-pc-none-elf \ + -Wl,-zmax-page-size=0x1000 diff --git a/kernel/amd64/init.c b/kernel/amd64/init.c new file mode 100644 index 0000000..3a1b6ad --- /dev/null +++ b/kernel/amd64/init.c @@ -0,0 +1,105 @@ +#include +#include +#include +#include +#include + +#define GDT_KCODE 0x08 +#define GDT_KDATA 0x10 +#define GDT_UCODE 0x18 +#define GDT_UDATA 0x20 +#define GDT_TSS 0x28 + +#define TSS 0x80 +#define TSS_PRESENT 0x89 + +#define KSTACK_SIZE (8*1024) + +struct gdt_entry { + uint16_t limitlow; + uint16_t baselow; + uint8_t basemid; + uint8_t access; + uint8_t gran; + uint8_t basehigh; +} __attribute__((packed)); + +struct gdt_ptr { + uint16_t limit; + uint64_t base; +} __attribute__((packed)); + +struct gdt_extended { + struct gdt_entry old[5]; + struct gdt_entry tsslow; + struct gdt_entry tsshigh; +} __attribute__((packed)); + +__attribute__((aligned(16))) static volatile uint8_t kernel_stack[KSTACK_SIZE]; +__attribute__((aligned(16))) static volatile struct gdt_extended gdt; + +static void amd64_gdt_set(volatile struct gdt_entry *ent, uint32_t base, + uint32_t limit, uint8_t acc, uint8_t gran) { + ent->baselow = (base & 0xFFFF); + ent->basemid = (base >> 16) & 0xFF; + ent->basehigh = (base >> 24) & 0xFF; + ent->limitlow = (limit & 0xFFFF); + ent->gran = ((limit >> 16) & 0x0F) | (gran & 0xF0); + ent->access = acc; +} + +static void amd64_gdt_init(void) { + volatile struct tss *tss = amd64_get_tss(); + + memset((void *)&gdt, 0, sizeof(gdt)); + memset((void *)kernel_stack, 0, sizeof(kernel_stack)); + memset((void *)tss, 0, sizeof(*tss)); + + tss->iopb_off = sizeof(*tss); + tss->rsp0 = (uint64_t)((uintptr_t)kernel_stack + sizeof(kernel_stack)); + + uint64_t tssbase = (uint64_t)&tss; + uint64_t tsslimit = sizeof(*tss) - 1; + + amd64_gdt_set(&gdt.old[0], 0, 0, 0, 0); + amd64_gdt_set(&gdt.old[1], 0, 0xFFFFF, 0x9A, 0xA0); + amd64_gdt_set(&gdt.old[2], 0, 0xFFFFF, 0x92, 0xC0); + amd64_gdt_set(&gdt.old[3], 0, 0xFFFFF, 0xFA, 0xA0); + amd64_gdt_set(&gdt.old[4], 0, 0xFFFFF, 0xF2, 0xC0); + amd64_gdt_set(&gdt.tsslow, (tssbase & 0xFFFFFFFF), tsslimit, TSS_PRESENT | TSS, 0); + + uint32_t tssbasehigh = (tssbase >> 32); + gdt.tsshigh.limitlow = (tssbasehigh & 0xFFFF); + gdt.tsshigh.baselow = (tssbasehigh >> 16) & 0xFFFF; + gdt.tsshigh.basemid = 0; + gdt.tsshigh.basehigh = 0; + gdt.tsshigh.access = 0; + gdt.tsshigh.gran = 0; + + struct gdt_ptr gdtr; + gdtr.limit = sizeof(gdt) - 1; + gdtr.base = (uint64_t)&gdt; + __asm__ volatile("lgdt %0" :: "m"(gdtr) : "memory"); + + __asm__ volatile( + "pushq %[kcode]\n" + "lea 1f(%%rip), %%rax\n" + "pushq %%rax\n" + "lretq\n" + "1:\n" + "movw %[kdata], %%ax\n" + "movw %%ax, %%ds\n" + "movw %%ax, %%es\n" + "movw %%ax, %%ss\n" + : + : [kcode] "i"(GDT_KCODE), [kdata] "i"(GDT_KDATA) + : "rax", "memory" + ); + + __asm__ volatile("ltr %0" :: "r"((uint16_t)GDT_TSS)); +} + +void amd64_init(void) { + amd64_gdt_init(); + amd64_debug_init(); +} diff --git a/kernel/amd64/init.h b/kernel/amd64/init.h new file mode 100644 index 0000000..82cec66 --- /dev/null +++ b/kernel/amd64/init.h @@ -0,0 +1,6 @@ +#ifndef _KERNEL_AMD64_INIT_H +#define _KERNEL_AMD64_INIT_H + +void amd64_init(void); + +#endif // _KERNEL_AMD64_INIT_H diff --git a/kernel/amd64/io.c b/kernel/amd64/io.c new file mode 100644 index 0000000..d636e63 --- /dev/null +++ b/kernel/amd64/io.c @@ -0,0 +1,54 @@ +#include +#include + +void amd64_io_outb(uint16_t port, uint8_t v) { + __asm__ volatile("outb %1, %0" :: "dN"(port), "a"(v)); +} + +void amd64_io_outw(uint16_t port, uint16_t v) { + __asm__ volatile("outw %%ax, %%dx" :: "a"(v), "d"(port)); +} + +void amd64_io_outl(uint16_t port, uint32_t v) { + __asm__ volatile("outl %%eax, %%dx" :: "d"(port), "a"(v)); +} + +void amd64_io_outsw(uint16_t port, const void *addr, int cnt) { + __asm__ volatile( + "cld; rep outsw" + : "+S"(addr), "+c"(cnt) + : "d"(port) + : "memory", "cc" + ); +} + +uint8_t amd64_io_inb(uint16_t port) { + uint8_t r; + __asm__ volatile("inb %1, %0" : "=a"(r) : "dN"(port)); + return r; +} + +uint16_t amd64_io_inw(uint16_t port) { + uint16_t r; + __asm__ volatile("inw %%dx, %%ax" : "=a"(r) : "d"(port)); + return r; +} + +uint32_t amd64_io_inl(uint16_t port) { + uint32_t r; + __asm__ volatile("inl %%dx, %%eax" : "=a"(r) : "d"(port)); + return r; +} + +void amd64_io_insw(uint16_t port, void *addr, int cnt) { + __asm__ volatile( + "cld; rep insw" + : "+D"(addr), "+c"(cnt) + : "d"(port) + : "memory", "cc" + ); +} + +void amd64_io_wait(void) { + amd64_io_outb(0x80, 0); +} diff --git a/kernel/amd64/io.h b/kernel/amd64/io.h new file mode 100644 index 0000000..9384949 --- /dev/null +++ b/kernel/amd64/io.h @@ -0,0 +1,16 @@ +#ifndef _KERNEL_AMD64_IO_H +#define _KERNEL_AMD64_IO_H + +#include + +void amd64_io_outb(uint16_t port, uint8_t v); +void amd64_io_outw(uint16_t port, uint16_t v); +void amd64_io_outl(uint16_t port, uint32_t v); +void amd64_io_outsw(uint16_t port, const void *addr, int cnt); +uint8_t amd64_io_inb(uint16_t port); +uint16_t amd64_io_inw(uint16_t port); +uint32_t amd64_io_inl(uint16_t port); +void amd64_io_insw(uint16_t port, void *addr, int cnt); +void amd64_io_wait(void); + +#endif // _KERNEL_AMD64_IO_H diff --git a/kernel/amd64/src.mk b/kernel/amd64/src.mk index 979860b..67af6b6 100644 --- a/kernel/amd64/src.mk +++ b/kernel/amd64/src.mk @@ -1,3 +1,11 @@ -c += amd64/bootmain.c +c += amd64/bootmain.c \ + amd64/init.c \ + amd64/tss.c \ + amd64/io.c \ + amd64/debug.c -o += amd64/bootmain.o +o += amd64/bootmain.o \ + amd64/init.o \ + amd64/tss.o \ + amd64/io.o \ + amd64/debug.o diff --git a/kernel/amd64/tss.c b/kernel/amd64/tss.c new file mode 100644 index 0000000..1f9e211 --- /dev/null +++ b/kernel/amd64/tss.c @@ -0,0 +1,8 @@ +#include +#include + +__attribute__((aligned(16))) static volatile struct tss tss; + +volatile struct tss *amd64_get_tss(void) { + return &tss; +} diff --git a/kernel/amd64/tss.h b/kernel/amd64/tss.h new file mode 100644 index 0000000..9745122 --- /dev/null +++ b/kernel/amd64/tss.h @@ -0,0 +1,20 @@ +#ifndef _KERNEL_AMD64_TSS_H +#define _KERNEL_AMD64_TSS_H + +#include + +struct tss { + uint32_t resv0; + uint64_t rsp0; + uint64_t rsp1; + uint64_t rsp2; + uint64_t resv1; + uint64_t ist[7]; + uint64_t resv2; + uint16_t resv3; + uint16_t iopb_off; +} __attribute__((packed)); + +volatile struct tss *amd64_get_tss(void); + +#endif // _KERNEL_AMD64_TSS_H diff --git a/kernel/generic/flags.mk b/kernel/generic/flags.mk index 64f07e8..dfd1f0a 100644 --- a/kernel/generic/flags.mk +++ b/kernel/generic/flags.mk @@ -5,10 +5,13 @@ cflags += -nostdinc \ -std=c11 \ -pedantic \ -Wall \ - -Wextra + -Wextra \ + -mcmodel=kernel cflags += -isystem . -isystem c_headers/include +cflags += -DPRINTF_INCLUDE_CONFIG_H=1 + ifeq ($(buildtype),debug) cflags += -O0 -g endif diff --git a/kernel/libk/.gitignore b/kernel/libk/.gitignore new file mode 100644 index 0000000..5761abc --- /dev/null +++ b/kernel/libk/.gitignore @@ -0,0 +1 @@ +*.o diff --git a/kernel/libk/printf.c b/kernel/libk/printf.c new file mode 100644 index 0000000..ce9dd32 --- /dev/null +++ b/kernel/libk/printf.c @@ -0,0 +1,1651 @@ +/** + * @author (c) Eyal Rozenberg + * 2021-2024, Haifa, Palestine/Israel + * @author (c) Marco Paland (info@paland.com) + * 2014-2019, PALANDesign Hannover, Germany + * + * @note Others have made smaller contributions to this file: see the + * contributors page at https://github.com/eyalroz/printf/graphs/contributors + * or ask one of the authors. The original code for exponential specifiers was + * contributed by Martijn Jasperse . + * + * @brief Small stand-alone implementation of the printf family of functions + * (`(v)printf`, `(v)s(n)printf` etc., geared towards use on embedded systems with + * limited resources. + * + * @note the implementations are thread-safe; re-entrant; use no functions from + * the standard library; and do not dynamically allocate any memory. + * + * @license The MIT License (MIT) + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +/* printf doesn't seem to like aggressive optimizations */ +#if defined(__clang__) + #pragma clang optimize off +#endif + +/* + * Define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H=1 ...) to include the + * printf_config.h header file + */ +#if PRINTF_INCLUDE_CONFIG_H +#include "printf_config.h" +#endif + +#include + +#ifdef __cplusplus +#include +#include +#else +#include +#include +#include +#endif /* __cplusplus */ + +#if !(defined(__cplusplus) || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L)) +/* C90 */ +#if defined(_MSC_VER) +#define inline __inline +#else +#define inline __inline__ +#endif /* defined(_MSC_VER) */ +#endif /* !(defined(__cplusplus) || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L)) */ + +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +# define printf_ printf +# define sprintf_ sprintf +# define vsprintf_ vsprintf +# define snprintf_ snprintf +# define vsnprintf_ vsnprintf +# define vprintf_ vprintf +#endif /* PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD */ + + +/* + * 'ntoa' conversion buffer size, this must be big enough to hold one converted + * numeric number including padded zeros (dynamically created on stack) + */ +#ifndef PRINTF_INTEGER_BUFFER_SIZE +#define PRINTF_INTEGER_BUFFER_SIZE 32 +#endif /* PRINTF_INTEGER_BUFFER_SIZE */ + +/* + * size of the fixed (on-stack) buffer for printing individual decimal numbers. + * this must be big enough to hold one converted floating-point value including + * padded zeros. + */ +#ifndef PRINTF_DECIMAL_BUFFER_SIZE +#define PRINTF_DECIMAL_BUFFER_SIZE 32 +#endif + +/* Support for the decimal notation floating point conversion specifiers (%f, %F) */ +#ifndef PRINTF_SUPPORT_DECIMAL_SPECIFIERS +#define PRINTF_SUPPORT_DECIMAL_SPECIFIERS 1 +#endif + +/* Support for the exponential notation floating point conversion specifiers (%e, %g, %E, %G) */ +#ifndef PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS +#define PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS 1 +#endif + +/* Support for the length write-back specifier (%n) */ +#ifndef PRINTF_SUPPORT_WRITEBACK_SPECIFIER +#define PRINTF_SUPPORT_WRITEBACK_SPECIFIER 1 +#endif + +/* Default precision for the floating point conversion specifiers (the C standard sets this at 6) */ +#ifndef PRINTF_DEFAULT_FLOAT_PRECISION +#define PRINTF_DEFAULT_FLOAT_PRECISION 6 +#endif + +/* Default choice of type to use for internal floating-point computations */ +#ifndef PRINTF_USE_DOUBLE_INTERNALLY +#define PRINTF_USE_DOUBLE_INTERNALLY 1 +#endif + +/* + * According to the C languages standard, printf() and related functions must be able to print any + * integral number in floating-point notation, regardless of length, when using the %f specifier - + * possibly hundreds of characters, potentially overflowing your buffers. In this implementation, + * all values beyond this threshold are switched to exponential notation. + */ +#ifndef PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL +#define PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL 9 +#endif + +/* + * Support for the long long integral types (with the ll, z and t length modifiers for specifiers + * %d,%i,%o,%x,%X,%u, and with the %p specifier). + */ +#ifndef PRINTF_SUPPORT_LONG_LONG +#define PRINTF_SUPPORT_LONG_LONG 1 +#endif + +/* + * The number of terms in a Taylor series expansion of log_10(x) to + * use for approximation - including the power-zero term (i.e. the + * value at the point of expansion). + */ +#ifndef PRINTF_LOG10_TAYLOR_TERMS +#define PRINTF_LOG10_TAYLOR_TERMS 4 +#endif + +#if PRINTF_LOG10_TAYLOR_TERMS <= 1 +#error "At least one non-constant Taylor expansion is necessary for the log10() calculation" +#endif + +/* + * Be extra-safe, and don't assume format specifiers are completed correctly + * before the format string end. + */ +#ifndef PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER +#define PRINTF_CHECK_FOR_NUL_IN_FORMAT_SPECIFIER 1 +#endif + +#define PRINTF_PREFER_DECIMAL false +#define PRINTF_PREFER_EXPONENTIAL true + +/*===========================================================================*/ + +/* The following will convert the number-of-digits into an exponential-notation literal */ +#define PRINTF_CONCATENATE(s1, s2) s1##s2 +#define PRINTF_EXPAND_THEN_CONCATENATE(s1, s2) PRINTF_CONCATENATE(s1, s2) +#define PRINTF_FLOAT_NOTATION_THRESHOLD ((floating_point_t) PRINTF_EXPAND_THEN_CONCATENATE(1e,PRINTF_MAX_INTEGRAL_DIGITS_FOR_DECIMAL)) + +/* internal flag definitions */ +#define FLAGS_ZEROPAD (1U << 0U) +#define FLAGS_LEFT (1U << 1U) +#define FLAGS_PLUS (1U << 2U) +#define FLAGS_SPACE (1U << 3U) +#define FLAGS_HASH (1U << 4U) +#define FLAGS_UPPERCASE (1U << 5U) +#define FLAGS_CHAR (1U << 6U) +#define FLAGS_SHORT (1U << 7U) +#define FLAGS_INT (1U << 8U) + /* Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS */ +#define FLAGS_LONG (1U << 9U) +#define FLAGS_LONG_LONG (1U << 10U) +#define FLAGS_PRECISION (1U << 11U) +#define FLAGS_ADAPT_EXP (1U << 12U) +#define FLAGS_POINTER (1U << 13U) + /* Note: Similar, but not identical, effect as FLAGS_HASH */ +#define FLAGS_SIGNED (1U << 14U) +#define FLAGS_LONG_DOUBLE (1U << 15U) + /* Only used with PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS */ + +#ifdef PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS + +#define FLAGS_INT8 FLAGS_CHAR + + +#if (SHRT_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_SHORT +#elif (INT_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_INT +#elif (LONG_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_LONG +#elif (LLONG_MAX == 32767LL) +#define FLAGS_INT16 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 16 bits exactly" +#endif + +#if (SHRT_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_SHORT +#elif (INT_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_INT +#elif (LONG_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_LONG +#elif (LLONG_MAX == 2147483647LL) +#define FLAGS_INT32 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 32 bits exactly" +#endif + +#if (SHRT_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_SHORT +#elif (INT_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_INT +#elif (LONG_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_LONG +#elif (LLONG_MAX == 9223372036854775807LL) +#define FLAGS_INT64 FLAGS_LONG_LONG +#else +#error "No basic integer type has a size of 64 bits exactly" +#endif + +#endif /* PRINTF_SUPPORT_MSVC_STYLE_INTEGER_SPECIFIERS */ + + +typedef unsigned int printf_flags_t; + +#define BASE_BINARY 2 +#define BASE_OCTAL 8 +#define BASE_DECIMAL 10 +#define BASE_HEX 16 + +typedef uint8_t numeric_base_t; + +#if PRINTF_SUPPORT_LONG_LONG +typedef unsigned long long printf_unsigned_value_t; +typedef long long printf_signed_value_t; +#else +typedef unsigned long printf_unsigned_value_t; +typedef long printf_signed_value_t; +#endif /* PRINTF_SUPPORT_LONG_LONG */ + +/* + * The printf()-family functions return an `int`; it is therefore + * unnecessary/inappropriate to use size_t - often larger than int + * in practice - for non-negative related values, such as widths, + * precisions, offsets into buffers used for printing and the sizes + * of these buffers. instead, we use: + */ +typedef unsigned int printf_size_t; +#define PRINTF_MAX_POSSIBLE_BUFFER_SIZE INT_MAX + /* + * If we were to nitpick, this would actually be INT_MAX + 1, + * since INT_MAX is the maximum return value, which excludes the + * trailing '\0'. + */ + +#define SIGN(_negative,_x) ( (_negative) ? -(_x) : (_x)) + +#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) +#include +#if FLT_RADIX != 2 +#error "Non-binary-radix floating-point types are unsupported." +#endif /* PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS */ + +/** + * This library supports taking float-point arguments up to and including + * long double's; but - it currently does _not_ support internal + * representation and manipulation of values as long doubles; the options + * are either single-precision `float` or double-precision `double`. + */ +#if PRINTF_USE_DOUBLE_INTERNALLY +typedef double floating_point_t; +#define FP_TYPE_MANT_DIG DBL_MANT_DIG +#else +typedef float floating_point_t; +#define FP_TYPE_MANT_DIG FLT_MANT_DIG +#endif + +#define NUM_DECIMAL_DIGITS_IN_INT64_T 18 + +#if FP_TYPE_MANT_DIG == 24 + +typedef uint32_t printf_fp_uint_t; +#define FP_TYPE_SIZE_IN_BITS 32 +#define FP_TYPE_EXPONENT_MASK 0xFFU +#define FP_TYPE_BASE_EXPONENT 127 +#define FP_TYPE_MAX FLT_MAX +#define FP_TYPE_MAX_10_EXP FLT_MAX_10_EXP +#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -38 +#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-38f +#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 10 + +#elif FP_TYPE_MANT_DIG == 53 + +typedef uint64_t printf_fp_uint_t; +#define FP_TYPE_SIZE_IN_BITS 64 +#define FP_TYPE_EXPONENT_MASK 0x7FFU +#define FP_TYPE_BASE_EXPONENT 1023 +#define FP_TYPE_MAX DBL_MAX +#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP +#define FP_TYPE_MAX_10_EXP DBL_MAX_10_EXP +#define FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10 -308 +#define FP_TYPE_MAX_SUBNORMAL_POWER_OF_10 1e-308 +#define PRINTF_MAX_PRECOMPUTED_POWER_OF_10 NUM_DECIMAL_DIGITS_IN_INT64_T - 1 + + +#else /* FP_TYPE_MANT_DIG is neither 24 nor 53 */ +#error "Unsupported floating point type configuration" +#endif /* FP_TYPE_MANT_DIG */ +#define FP_TYPE_STORED_MANTISSA_BITS (FP_TYPE_MANT_DIG - 1) + +typedef union { + printf_fp_uint_t U; + floating_point_t F; +} floating_point_with_bit_access; + +/* + * This is unnecessary in C99, since compound initializers can be used, + * but: + * 1. Some compilers are finicky about this; + * 2. Some people may want to convert this to C89; + * 3. If you try to use it as C++, only C++20 supports compound literals + */ +static inline floating_point_with_bit_access get_bit_access(floating_point_t x) +{ + floating_point_with_bit_access dwba; + dwba.F = x; + return dwba; +} + +static inline int get_sign_bit(floating_point_t x) +{ + /* The sign is stored in the highest bit */ + return (int) (get_bit_access(x).U >> (FP_TYPE_SIZE_IN_BITS - 1)); +} + +static inline int get_exp2(floating_point_with_bit_access x) +{ + /* + * The exponent in an IEEE-754 floating-point number occupies a contiguous + * sequence of bits (e.g. 52..62 for 64-bit doubles), but with a non-trivial representation: An + * unsigned offset from some negative value (with the extremal offset values reserved for + * special use). + */ + return (int)((x.U >> FP_TYPE_STORED_MANTISSA_BITS ) & FP_TYPE_EXPONENT_MASK) - FP_TYPE_BASE_EXPONENT; +} +#define PRINTF_ABS(_x) SIGN( (_x) < 0, (_x) ) + +#endif /* (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) */ + +/* + * Note in particular the behavior here on LONG_MIN or LLONG_MIN; it is valid + * and well-defined, but if you're not careful you can easily trigger undefined + * behavior with -LONG_MIN or -LLONG_MIN + */ +#define ABS_FOR_PRINTING(_x) ((printf_unsigned_value_t) ( (_x) > 0 ? (_x) : -((printf_signed_value_t)_x) )) + +/* + * wrapper (used as buffer) for output function type + * + * One of the following must hold: + * 1. max_chars is 0 + * 2. buffer is non-null + * 3. function is non-null + * + * ... otherwise bad things will happen. + */ +typedef struct { + void (*function)(char c, void* extra_arg); + void* extra_function_arg; + char* buffer; + printf_size_t pos; + printf_size_t max_chars; +} output_gadget_t; + +/* + * Note: This function currently assumes it is not passed a '\0' c, + * or alternatively, that '\0' can be passed to the function in the output + * gadget. The former assumption holds within the printf library. It also + * assumes that the output gadget has been properly initialized. + */ +static inline void putchar_via_gadget(output_gadget_t* gadget, char c) +{ + printf_size_t write_pos = gadget->pos++; + /* + * We're _always_ increasing pos, so as to count how may characters + * _would_ have been written if not for the max_chars limitation + */ + if (write_pos >= gadget->max_chars) { + return; + } + if (gadget->function != NULL) { + /* No check for c == '\0' . */ + gadget->function(c, gadget->extra_function_arg); + } + else { + /* + * it must be the case that gadget->buffer != NULL , due to the constraint + * on output_gadget_t ; and note we're relying on write_pos being non-negative. + */ + gadget->buffer[write_pos] = c; + } +} + +/* Possibly-write the string-terminating '\0' character */ +static inline void append_termination_with_gadget(output_gadget_t* gadget) +{ + printf_size_t null_char_pos; + if (gadget->function != NULL || gadget->max_chars == 0) { + return; + } + if (gadget->buffer == NULL) { + return; + } + null_char_pos = gadget->pos < gadget->max_chars ? gadget->pos : gadget->max_chars - 1; + gadget->buffer[null_char_pos] = '\0'; +} + +/* + * We can't use putchar_ as is, since our output gadget + * only takes pointers to functions with an extra argument + */ +static inline void putchar_wrapper(char c, void* unused) +{ + (void) unused; + putchar_(c); +} + +static inline output_gadget_t discarding_gadget(void) +{ + output_gadget_t gadget; + gadget.function = NULL; + 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; +} + +static inline output_gadget_t function_gadget(void (*function)(char, void*), void* extra_arg) +{ + output_gadget_t result = discarding_gadget(); + result.function = function; + result.extra_function_arg = extra_arg; + result.max_chars = PRINTF_MAX_POSSIBLE_BUFFER_SIZE; + return result; +} + +static inline output_gadget_t extern_putchar_gadget(void) +{ + return function_gadget(putchar_wrapper, NULL); +} + +/* + * 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)) { + printf_size_t i; + for (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 < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + while ((len < precision) && (len < PRINTF_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 < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'x'; + } + else if ((base == BASE_HEX) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'X'; + } + else if ((base == BASE_BINARY) && (len < PRINTF_INTEGER_BUFFER_SIZE)) { + buf[len++] = 'b'; + } + if (len < PRINTF_INTEGER_BUFFER_SIZE) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_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[PRINTF_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 < PRINTF_INTEGER_BUFFER_SIZE)); + } + + print_integer_finalization(output, buf, len, negative, base, precision, width, flags); +} + +#if (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS) + +/* + * Stores a fixed-precision representation of a floating-point number relative + * to a fixed precision (which cannot be determined by examining this structure) + */ +struct floating_point_components { + int_fast64_t integral; + int_fast64_t fractional; + /* + * ... truncation of the actual fractional part of the floating_point_t value, scaled + * by the precision value + */ + bool is_negative; +}; + +static const floating_point_t powers_of_10[PRINTF_MAX_PRECOMPUTED_POWER_OF_10 + 1] = { + 1e00, 1e01, 1e02, 1e03, 1e04, 1e05, 1e06, 1e07, 1e08, 1e09, 1e10 +#if PRINTF_MAX_PRECOMPUTED_POWER_OF_10 > 10 + , 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17 +#endif +}; + +/* + * Note: This value does not mean that all floating-point values printed with the + * library will be correct up to this precision; it is just an upper-bound for + * avoiding buffer overruns and such + */ +#define PRINTF_MAX_SUPPORTED_PRECISION (NUM_DECIMAL_DIGITS_IN_INT64_T - 1) + + +/* + * Break up a non-negative, finite, floating-point number into two integral + * parts of its decimal representation: The number up to the decimal point, + * and the number appearing after that point - whose number of digits + * corresponds to the precision value. Example: The components of 12.621 + * are 12 and 621 for precision 3, or 12 and 62 for precision 2. + */ +static struct floating_point_components get_components(floating_point_t number, printf_size_t precision) +{ + struct floating_point_components number_; + floating_point_t abs_number; + floating_point_t scaled_remainder; + floating_point_t remainder; + const floating_point_t one_half = (floating_point_t) 0.5; + number_.is_negative = get_sign_bit(number); + abs_number = SIGN(number_.is_negative, number); + number_.integral = (int_fast64_t) abs_number; + scaled_remainder = (abs_number - (floating_point_t) number_.integral) * powers_of_10[precision]; + number_.fractional = (int_fast64_t) scaled_remainder; /* for precision == 0U, this will be 0 */ + + remainder = scaled_remainder - (floating_point_t) number_.fractional; + + if ((remainder > one_half) || + /* Banker's rounding, i.e. round half to even: 1.5 -> 2, but 2.5 -> 2 */ + ((remainder == one_half) && (number_.fractional & 1U))) { + ++number_.fractional; + } + if ((floating_point_t) number_.fractional >= powers_of_10[precision]) { + number_.fractional = 0; + ++number_.integral; + } + + if (precision == 0U) { + remainder = abs_number - (floating_point_t) number_.integral; + if ((remainder == one_half) && (number_.integral & 1U)) { + /* + * Banker's rounding, i.e. round half to even: + * 1.5 -> 2, but 2.5 -> 2 + */ + ++number_.integral; + } + } + return number_; +} + +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS +struct scaling_factor { + floating_point_t raw_factor; + bool multiply; /* if true, need to multiply by raw_factor; otherwise need to divide by it */ +}; + +static floating_point_t apply_scaling(floating_point_t num, struct scaling_factor normalization) +{ + return normalization.multiply ? num * normalization.raw_factor : num / normalization.raw_factor; +} + +static floating_point_t unapply_scaling(floating_point_t normalized, struct scaling_factor normalization) +{ +#ifdef __GNUC__ +/* accounting for a static analysis bug in GCC 6.x and earlier */ +#pragma GCC diagnostic push +#if !defined(__has_warning) +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#elif __has_warning("-Wmaybe-uninitialized") +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#endif +#endif + return normalization.multiply ? normalized / normalization.raw_factor : normalized * normalization.raw_factor; +#ifdef __GNUC__ +#pragma GCC diagnostic pop +#endif +} + +static struct scaling_factor update_normalization(struct scaling_factor sf, floating_point_t 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 floating_point_components get_normalized_components(bool negative, printf_size_t precision, floating_point_t non_normalized, struct scaling_factor normalization, int floored_exp10) +{ + struct floating_point_components components; + floating_point_t scaled; + bool close_to_representation_extremum; + floating_point_t remainder; + floating_point_t prec_power_of_10; + struct scaling_factor account_for_precision; + floating_point_t scaled_remainder; + const floating_point_t rounding_threshold = 0.5; + + components.is_negative = negative; + scaled = apply_scaling(non_normalized, normalization); + + close_to_representation_extremum = ( (-floored_exp10 + (int) precision) >= FP_TYPE_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(SIGN(negative, scaled), precision); + } + components.integral = (int_fast64_t) scaled; + remainder = non_normalized - unapply_scaling((floating_point_t) components.integral, normalization); + prec_power_of_10 = powers_of_10[precision]; + account_for_precision = update_normalization(normalization, prec_power_of_10); + scaled_remainder = apply_scaling(remainder, account_for_precision); + + components.fractional = (int_fast64_t) scaled_remainder; /* when precision == 0, the assigned value should be 0 */ + scaled_remainder -= (floating_point_t) 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 ((floating_point_t) components.fractional >= prec_power_of_10) { + components.fractional = 0; + ++components.integral; + } + return components; +} +#endif /* PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS */ + +static void print_broken_up_decimal( + struct floating_point_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 < PRINTF_DECIMAL_BUFFER_SIZE) { + --count; + buf[len++] = (char)('0' + number_.fractional % 10U); + if (!(number_.fractional /= 10U)) { + break; + } + } + /* add extra 0s */ + while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (count > 0U)) { + buf[len++] = '0'; + --count; + } + if (len < PRINTF_DECIMAL_BUFFER_SIZE) { + buf[len++] = '.'; + } + } + } + else { + if ((flags & FLAGS_HASH) && (len < PRINTF_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 < PRINTF_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 < PRINTF_DECIMAL_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_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, floating_point_t number, printf_size_t precision, printf_size_t width, printf_flags_t flags, char* buf, printf_size_t len) +{ + struct floating_point_components value_ = get_components(number, precision); + print_broken_up_decimal(value_, output, precision, width, flags, buf, len); +} + +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + +/* + * A floor function - but one which only works for numbers whose + * floor value is representable by an int. + */ +static int bastardized_floor(floating_point_t x) +{ + int n; + if (x >= 0) { return (int) x; } + n = (int) x; + return ( ((floating_point_t) 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 floating_point_t log10_of_positive(floating_point_t 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. + */ + + floating_point_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); + floating_point_t z; + /* drop the exponent, so dwba.F comes into the range [1,2) */ + dwba.U = (dwba.U & (((printf_fp_uint_t) (1) << FP_TYPE_STORED_MANTISSA_BITS) - 1U)) | + ((printf_fp_uint_t) FP_TYPE_BASE_EXPONENT << FP_TYPE_STORED_MANTISSA_BITS); + z = (dwba.F - (floating_point_t) 1.5); + return ( + /* Taylor expansion around 1.5: */ + (floating_point_t) 0.1760912590556812420 /* Expansion term 0: ln(1.5) / ln(10) */ + + z * (floating_point_t) 0.2895296546021678851 /* Expansion term 1: (M - 1.5) * 2/3 / ln(10) */ +#if PRINTF_LOG10_TAYLOR_TERMS > 2 + - z*z * (floating_point_t) 0.0965098848673892950 /* Expansion term 2: (M - 1.5)^2 * 2/9 / ln(10) */ +#if PRINTF_LOG10_TAYLOR_TERMS > 3 + + z*z*z * (floating_point_t) 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 */ + + (floating_point_t) exp2 * (floating_point_t) 0.30102999566398119521 /* = exp2 * log_10(2) = exp2 * ln(2)/ln(10) */ + ); +} + + +static floating_point_t pow10_of_int(int floored_exp10) +{ + floating_point_with_bit_access dwba; + int exp2; + floating_point_t z; + floating_point_t z2; + + /* A crude hack for avoiding undesired behavior with barely-normal or slightly-subnormal values. */ + if (floored_exp10 == FP_TYPE_MAX_SUBNORMAL_EXPONENT_OF_10) { + return FP_TYPE_MAX_SUBNORMAL_POWER_OF_10; + } + /* Compute 10^(floored_exp10) but (try to) make sure that doesn't overflow */ + exp2 = bastardized_floor(floored_exp10 * (floating_point_t) 3.321928094887362 + (floating_point_t) 0.5); + z = floored_exp10 * (floating_point_t) 2.302585092994046 - exp2 * (floating_point_t) 0.6931471805599453; + z2 = z * z; + dwba.U = ((printf_fp_uint_t)(exp2) + FP_TYPE_BASE_EXPONENT) << FP_TYPE_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, floating_point_t 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 */ + floating_point_t abs_number = SIGN(negative, number); + + int floored_exp10; + bool abs_exp10_covered_by_powers_table; + struct scaling_factor normalization; + struct floating_point_components decimal_part_components; + int original_floored_exp10; + bool fall_back_to_decimal_only_mode; + printf_size_t exp10_part_width; + printf_size_t decimal_part_width; + printf_size_t printed_exponential_start_pos; + + + /* Determine the decimal exponent */ + if (abs_number == (floating_point_t) 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 { + floating_point_t exp10 = log10_of_positive(abs_number); + floating_point_t p10; + floored_exp10 = bastardized_floor(exp10); + 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; + } + + if (flags & FLAGS_ADAPT_EXP) { + /* + * Note: For now, still assuming we _don't_ fall-back to "%f" mode; we can't decide + * that until we've established the exact exponent. + */ + + /* + * In "%g" mode, "precision" is the number of _significant digits_; we must + * "translate" that to an actual number of decimal digits. + */ + precision = (precision > 1) ? (precision - 1U) : 0U; + flags |= FLAGS_PRECISION; /* make sure print_broken_up_decimal respects our choice */ + } + + /* + * 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". + */ + +#ifdef __GNUC__ +/* accounting for a static analysis bug in GCC 6.x and earlier */ +#pragma GCC diagnostic push +#if !defined(__has_warning) +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#elif __has_warning("-Wmaybe-uninitialized") +#pragma GCC diagnostic ignored "-Wmaybe-uninitialized" +#endif +#endif + normalization.multiply = (floored_exp10 < 0 && abs_exp10_covered_by_powers_table); +#ifdef __GNUC__ +#pragma GCC diagnostic pop +#endif + decimal_part_components = + (floored_exp10 == 0) ? + get_components(SIGN(negative, 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 + * (and saving the floored_exp10 in case we'll need to undo the roll-over). + */ + original_floored_exp10 = floored_exp10; + if (decimal_part_components.integral >= 10) { + floored_exp10++; + decimal_part_components.integral = 1; + decimal_part_components.fractional = 0; + } + + /* + * Should we want to fall-back to "%f" mode, and only print the decimal part? + * (and remember we have decreased "precision" by 1 + */ + fall_back_to_decimal_only_mode = (flags & FLAGS_ADAPT_EXP) && (floored_exp10 >= -4) && (floored_exp10 < (int) precision + 1); + + if (fall_back_to_decimal_only_mode) { + precision = ((int) precision > floored_exp10) ? (unsigned) ((int) precision - floored_exp10) : 0U; + /* Redo some work :-) */ + floored_exp10 = original_floored_exp10; + decimal_part_components = get_components(SIGN(negative, abs_number), precision); + 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 */ + if (precision > 0U) { precision--; } + /* ... and it should already be the case that decimal_part_components.fractional == 0 */ + } + /* TODO: What about rollover strictly within the fractional part? */ + } + + /* + * 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 + */ + exp10_part_width = fall_back_to_decimal_only_mode ? 0U : (PRINTF_ABS(floored_exp10) < 100) ? 4U : 5U; + + 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); + + 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 /* PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS */ + +static void print_floating_point(output_gadget_t* output, floating_point_t value, printf_size_t precision, printf_size_t width, printf_flags_t flags, bool prefer_exponential) +{ + char buf[PRINTF_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 < -FP_TYPE_MAX) { + out_rev_(output, "fni-", 4, width, flags); + return; + } + if (value > FP_TYPE_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. + */ +#if PRINTF_SUPPORT_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 = PRINTF_DEFAULT_FLOAT_PRECISION; + } + + /* limit precision so that our integer holding the fractional part does not overflow */ + while ((len < PRINTF_DECIMAL_BUFFER_SIZE) && (precision > PRINTF_MAX_SUPPORTED_PRECISION)) { + buf[len++] = '0'; /* This respects the precision in terms of result length only */ + precision--; + } + +#if PRINTF_SUPPORT_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 /* (PRINTF_SUPPORT_DECIMAL_SPECIFIERS || PRINTF_SUPPORT_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) +{ +#if PRINTF_CHECK_FOR_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) + { + printf_flags_t flags; + printf_size_t width; + printf_size_t precision; + 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); + + flags = parse_flags(&format); + + /* evaluate width field */ + width = 0U; + if (is_digit_(*format)) { + /* + * Note: If the width is negative, we've already parsed its + * sign character '-' as a FLAG_LEFT + */ + 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 */ + precision = 0U; + if (*format == '.') { + flags |= FLAGS_PRECISION; + ADVANCE_IN_FORMAT_STRING(format); + if (*format == '-') { + do { + ADVANCE_IN_FORMAT_STRING(format); + } while (is_digit_(*format)); + flags &= ~FLAGS_PRECISION; + } + else if (is_digit_(*format)) { + precision = atou_(&format); + } + else if (*format == '*') { + const int precision_ = va_arg(args, int); + if (precision_ < 0) { + flags &= ~FLAGS_PRECISION; + } + else { + precision = precision_ > 0 ? (printf_size_t) precision_ : 0U; + } + ADVANCE_IN_FORMAT_STRING(format); + } + } + + /* evaluate length field */ + switch (*format) { +#ifdef PRINTF_SUPPORT_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 'L' : + flags |= FLAGS_LONG_DOUBLE; + 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(int) ) ? FLAGS_INT : (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(int) ) ? FLAGS_INT : (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' : { + numeric_base_t base; + + if (*format == 'd' || *format == 'i') { + flags |= FLAGS_SIGNED; + } + + 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) { +#if PRINTF_SUPPORT_LONG_LONG + 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) { +#if PRINTF_SUPPORT_LONG_LONG + 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; + } +#if PRINTF_SUPPORT_DECIMAL_SPECIFIERS + case 'f' : + case 'F' : { + floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); + if (*format == 'F') flags |= FLAGS_UPPERCASE; + print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_DECIMAL); + format++; + break; + } +#endif +#if PRINTF_SUPPORT_EXPONENTIAL_SPECIFIERS + case 'e': + case 'E': + case 'g': + case 'G': { + floating_point_t value = (floating_point_t) (flags & FLAGS_LONG_DOUBLE ? va_arg(args, long double) : va_arg(args, double)); + if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP; + if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE; + print_floating_point(output, value, precision, width, flags, PRINTF_PREFER_EXPONENTIAL); + format++; + break; + } +#endif /* PRINTF_SUPPORT_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' : { + uintptr_t value; + width = sizeof(void*) * 2U + 2; /* 2 hex chars per byte + the "0x" prefix */ + flags |= FLAGS_ZEROPAD | FLAGS_POINTER; + 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. + */ +#if PRINTF_SUPPORT_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; +#if PRINTF_SUPPORT_LONG_LONG + else if (flags & FLAGS_LONG_LONG) *(va_arg(args, long long*)) = (long long int) output->pos; +#endif /* PRINTF_SUPPORT_LONG_LONG */ + else *(va_arg(args, int*)) = (int) output->pos; + format++; + break; + } +#endif /* PRINTF_SUPPORT_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; +} + +/*===========================================================================*/ + +int vprintf_(const char* format, va_list arg) +{ + output_gadget_t gadget = extern_putchar_gadget(); + return vsnprintf_impl(&gadget, format, arg); +} + +int vsnprintf_(char* s, size_t n, const char* format, va_list arg) +{ + output_gadget_t gadget = buffer_gadget(s, n); + return vsnprintf_impl(&gadget, format, arg); +} + +int vsprintf_(char* s, const char* format, va_list arg) +{ + return vsnprintf_(s, PRINTF_MAX_POSSIBLE_BUFFER_SIZE, format, arg); +} + +int vfctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, va_list arg) +{ + output_gadget_t gadget; + if (out == NULL) { return 0; } + gadget = function_gadget(out, extra_arg); + return vsnprintf_impl(&gadget, format, arg); +} + +int printf_(const char* format, ...) +{ + int ret; + va_list args; + va_start(args, format); + ret = vprintf_(format, args); + va_end(args); + return ret; +} + +int sprintf_(char* s, const char* format, ...) +{ + int ret; + va_list args; + va_start(args, format); + ret = vsprintf_(s, format, args); + va_end(args); + return ret; +} + +int snprintf_(char* s, size_t n, const char* format, ...) +{ + int ret; + va_list args; + va_start(args, format); + ret = vsnprintf_(s, n, format, args); + va_end(args); + return ret; +} + +int fctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, ...) +{ + int ret; + va_list args; + va_start(args, format); + ret = vfctprintf(out, extra_arg, format, args); + va_end(args); + return ret; +} + diff --git a/kernel/libk/printf.h b/kernel/libk/printf.h new file mode 100644 index 0000000..87715ed --- /dev/null +++ b/kernel/libk/printf.h @@ -0,0 +1,242 @@ +/** + * @author (c) Eyal Rozenberg + * 2021-2024, Haifa, Palestine/Israel + * @author (c) Marco Paland (info@paland.com) + * 2014-2019, PALANDesign Hannover, Germany + * + * @note Others have made smaller contributions to this file: see the + * contributors page at https://github.com/eyalroz/printf/graphs/contributors + * or ask one of the authors. + * + * @brief Small stand-alone implementation of the printf family of functions + * (`(v)printf`, `(v)s(n)printf` etc., geared towards use on embedded systems + * with a very limited resources. + * + * @note the implementations are thread-safe; re-entrant; use no functions from + * the standard library; and do not dynamically allocate any memory. + * + * @license The MIT License (MIT) + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef PRINTF_H_ +#define PRINTF_H_ + +#ifdef PRINTF_INCLUDE_CONFIG_H +#include "printf_config.h" +#endif + +#ifdef __cplusplus +# include +# include +extern "C" { +#else +# include +# include +#endif + +#ifdef __GNUC__ +# if ((__GNUC__ == 4 && __GNUC_MINOR__>= 4) || __GNUC__ > 4) +# define ATTR_PRINTF(one_based_format_index, first_arg) \ +__attribute__((format(gnu_printf, (one_based_format_index), (first_arg)))) +# else +# define ATTR_PRINTF(one_based_format_index, first_arg) \ +__attribute__((format(printf, (one_based_format_index), (first_arg)))) +# endif +# define ATTR_VPRINTF(one_based_format_index) \ +ATTR_PRINTF((one_based_format_index), 0) +#else +# define ATTR_PRINTF(one_based_format_index, first_arg) +# define ATTR_VPRINTF(one_based_format_index) +#endif + +#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT 0 +#endif + +#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD 0 +#endif + +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +# define printf_ printf +# define sprintf_ sprintf +# define vsprintf_ vsprintf +# define snprintf_ snprintf +# define vsnprintf_ vsnprintf +# define vprintf_ vprintf +#endif + +/* + * If you want to include this implementation file directly rather than + * link against it, this will let you control the functions' visibility, + * e.g. make them static so as not to clash with other objects also + * using them. + */ +#ifndef PRINTF_VISIBILITY +#define PRINTF_VISIBILITY +#endif + +/** + * Prints/send a single character to some opaque output entity + * + * @note This function is not implemented by the library, only declared; you + * must provide an implementation if you wish to use the @ref printf / @ref + * vprintf function (and possibly for linking against the library, if your + * toolchain does not support discarding unused functions) + * + * @note The output could be as simple as a wrapper for the `write()` system + * call on a Unix-like * system, or even libc's @ref putchar , for replicating + * actual functionality of libc's @ref printf * function; but on an embedded + * system it may involve interaction with a special output device, like a UART, + * etc. + * + * @note in libc's @ref putchar, the parameter type is an int; this was intended + * to support the representation of either a proper character or EOF in a + * variable - but this is really not meaningful to pass into @ref putchar and is + * discouraged today. See further discussion in: + * @link https://stackoverflow.com/q/17452847/1593077 + * + * @param c the single character to print + */ +PRINTF_VISIBILITY +void putchar_(char c); + + +/** + * An implementation of the C standard's printf/vprintf + * + * @note you must implement a @ref putchar_ function for using this function - + * it invokes @ref putchar_ * rather than directly performing any I/O (which + * insulates it from any dependence on the operating system * and external + * libraries). + * + * @param format A string specifying the format of the output, with %-marked + * specifiers of how to interpret additional arguments. + * @param arg Additional arguments to the function, one for each %-specifier in + * @p format + * @return The number of characters written into @p s, not counting the + * terminating null character + */ +/* @{ */ +PRINTF_VISIBILITY +int printf_(const char* format, ...) ATTR_PRINTF(1, 2); +PRINTF_VISIBILITY +int vprintf_(const char* format, va_list arg) ATTR_VPRINTF(1); +/* @} */ + + +/** + * An implementation of the C standard's sprintf/vsprintf + * + * @note For security considerations (the potential for exceeding the buffer + * bounds), please consider using the size-constrained variant, @ref snprintf / + * @ref vsnprintf, instead. + * + * @param s An array in which to store the formatted string. It must be large + * enough to fit the formatted output! + * @param format A string specifying the format of the output, with %-marked + * specifiers of how to interpret additional arguments + * @param arg Additional arguments to the function, one for each specifier in + * @p format + * @return The number of characters written into @p s, not counting the + * terminating null character + */ +/* @{ */ +PRINTF_VISIBILITY +int sprintf_(char* s, const char* format, ...) ATTR_PRINTF(2, 3); +PRINTF_VISIBILITY +int vsprintf_(char* s, const char* format, va_list arg) ATTR_VPRINTF(2); +/* @} */ + + +/** + * An implementation of the C standard's snprintf/vsnprintf + * + * @param s An array in which to store the formatted string. It must be large + * enough to fit either the entire formatted output, or at least @p n + * characters. Alternatively, it can be NULL, in which case nothing will + * be printed, and only the number of characters which _could_ have been + * printed is tallied and returned. + * @param n The maximum number of characters to write to the array, including + * a terminating null character + * @param format A string specifying the format of the output, with %-marked + * specifiers of how to interpret additional arguments. + * @param arg Additional arguments to the function, one for each specifier in + * @p format + * @return The number of characters that COULD have been written into @p s, not + * counting the terminating null character. A value equal or larger than + * @p n indicates truncation. Only when the returned value is non-negative + * and less than @p n, the null-terminated string has been fully and + * successfully printed. + */ +/* @{ */ +PRINTF_VISIBILITY +int snprintf_(char* s, size_t count, const char* format, ...) ATTR_PRINTF(3, 4); +PRINTF_VISIBILITY +int vsnprintf_(char* s, size_t count, const char* format, va_list arg) ATTR_VPRINTF(3); +/* @} */ + +/** + * printf/vprintf with user-specified output function + * + * An alternative to @ref printf_, in which the output function is specified + * dynamically (rather than @ref putchar_ being used) + * + * @param out An output function which takes one character and a type-erased + * additional parameters + * @param extra_arg The type-erased argument to pass to the output function @p + * out with each call + * @param format A string specifying the format of the output, with %-marked + * specifiers of how to interpret additional arguments. + * @param arg Additional arguments to the function, one for each specifier in + * @p format + * @return The number of characters for which the output f unction was invoked, + * not counting the terminating null character + * + */ +PRINTF_VISIBILITY +int fctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, ...) ATTR_PRINTF(3, 4); +PRINTF_VISIBILITY +int vfctprintf(void (*out)(char c, void* extra_arg), void* extra_arg, const char* format, va_list arg) ATTR_VPRINTF(3); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD +# undef printf_ +# undef sprintf_ +# undef vsprintf_ +# undef snprintf_ +# undef vsnprintf_ +# undef vprintf_ +#else +#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_SOFT +# define printf printf_ +# define sprintf sprintf_ +# define vsprintf vsprintf_ +# define snprintf snprintf_ +# define vsnprintf vsnprintf_ +# define vprintf vprintf_ +#endif +#endif + +#endif /* PRINTF_H_ */ diff --git a/kernel/libk/printf_config.h b/kernel/libk/printf_config.h new file mode 100644 index 0000000..127e3ef --- /dev/null +++ b/kernel/libk/printf_config.h @@ -0,0 +1,6 @@ +#ifndef _KERNEL_LIBK_PRINTF_CONFIG_H +#define _KERNEL_LIBK_PRINTF_CONFIG_H + +#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES_HARD 1 + +#endif // _KERNEL_LIBK_PRINTF_CONFIG_H diff --git a/kernel/libk/putchar_.c b/kernel/libk/putchar_.c new file mode 100644 index 0000000..f79ce03 --- /dev/null +++ b/kernel/libk/putchar_.c @@ -0,0 +1,3 @@ + +void putchar_(char x) { (void)x; } + diff --git a/kernel/libk/src.mk b/kernel/libk/src.mk new file mode 100644 index 0000000..4f719fa --- /dev/null +++ b/kernel/libk/src.mk @@ -0,0 +1,7 @@ +c += libk/string.c \ + libk/printf.c \ + libk/putchar_.c + +o += libk/string.o \ + libk/printf.o \ + libk/putchar_.o diff --git a/kernel/libk/std.h b/kernel/libk/std.h new file mode 100644 index 0000000..89786d7 --- /dev/null +++ b/kernel/libk/std.h @@ -0,0 +1,12 @@ +#ifndef _KERNEL_LIBK_STD_H +#define _KERNEL_LIBK_STD_H + +#include +#include +#include +#include +#include +#include +#include + +#endif // _KERNEL_LIBK_STD_H diff --git a/kernel/libk/string.c b/kernel/libk/string.c new file mode 100644 index 0000000..38b0db2 --- /dev/null +++ b/kernel/libk/string.c @@ -0,0 +1,44 @@ +#include +#include + +size_t memset(void *dst, uint8_t b, size_t n) { + uint8_t *dst1 = dst; + size_t i; + for (i = 0; i < n; i++) + dst1[i] = b; + return i; +} + +size_t memcpy(void *dst, const void *src, size_t n) { + uint8_t *dst1 = dst; + const uint8_t *src1 = src; + size_t i; + for (i = 0; i < n; i++) + dst1[i] = src1[i]; + return i; +} + +// SOURCE: https://stackoverflow.com/a/48967408 +void strncpy(char* dst, const char* src, size_t n) { + size_t i = 0; + while(i++ != n && (*dst++ = *src++)); +} + +size_t strlen(const char *str) { + const char *s; + for (s = str; *s; ++s); + return (s - str); +} + +int memcmp(const void *s1, const void *s2, size_t n) { + unsigned char *p = (unsigned char *)s1; + unsigned char *q = (unsigned char *)s2; + + while (n--) { + if (*p != *q) { + return (int)*p - (int)*q; + } + p++, q++; + } + return 0; +} diff --git a/kernel/libk/string.h b/kernel/libk/string.h new file mode 100644 index 0000000..b0f9342 --- /dev/null +++ b/kernel/libk/string.h @@ -0,0 +1,10 @@ +#ifndef _KERNEL_LIBK_STRING_H +#define _KERNEL_LIBK_STRING_H + +size_t memset(void *dst, uint8_t b, size_t n); +size_t memcpy(void *dst, const void *src, size_t n); +void strncpy(char* dst, const char* src, size_t n); +size_t strlen(const char *str); +int memcmp(const void *s1, const void *s2, size_t n); + +#endif // _KERNEL_LIBK_STRING_H diff --git a/kernel/sys/debug.h b/kernel/sys/debug.h new file mode 100644 index 0000000..e3d732b --- /dev/null +++ b/kernel/sys/debug.h @@ -0,0 +1,10 @@ +#ifndef _KERNEL_SYS_DEBUG_H +#define _KERNEL_SYS_DEBUG_H + +void debugprintf(const char *fmt, ...); + +#define DEBUG(fmt, ...) do { \ + debugprintf("%s: " fmt, __PRETTY_FUNCTION__, ##__VA_ARGS__); \ + } while(0) + +#endif // _KERNEL_SYS_DEBUG_H