path: root/tools/include/nolibc/stdio.h

/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
 * minimal stdio function definitions for NOLIBC
 * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
 */

/* make sure to include all global symbols */
#include "nolibc.h"

#ifndef _NOLIBC_STDIO_H
#define _NOLIBC_STDIO_H

#include "std.h"
#include "arch.h"
#include "errno.h"
#include "fcntl.h"
#include "types.h"
#include "sys.h"
#include "stdarg.h"
#include "stdlib.h"
#include "string.h"
#include "compiler.h"

static const char *strerror(int errnum);

#ifndef EOF
#define EOF (-1)
#endif

/* Buffering mode used by setvbuf.  */
#define _IOFBF 0	/* Fully buffered. */
#define _IOLBF 1	/* Line buffered. */
#define _IONBF 2	/* No buffering. */

/* just define FILE as a non-empty type. The value of the pointer gives
 * the FD: FILE=~fd for fd>=0 or NULL for fd<0. This way positive FILE
 * are immediately identified as abnormal entries (i.e. possible copies
 * of valid pointers to something else).
 */
typedef struct FILE {
	char dummy[1];
} FILE;

static __attribute__((unused)) FILE* const stdin  = (FILE*)(intptr_t)~STDIN_FILENO;
static __attribute__((unused)) FILE* const stdout = (FILE*)(intptr_t)~STDOUT_FILENO;
static __attribute__((unused)) FILE* const stderr = (FILE*)(intptr_t)~STDERR_FILENO;

/* provides a FILE* equivalent of fd. The mode is ignored. */
static __attribute__((unused))
FILE *fdopen(int fd, const char *mode __attribute__((unused)))
{
	if (fd < 0) {
		SET_ERRNO(EBADF);
		return NULL;
	}
	return (FILE*)(intptr_t)~fd;
}

static __attribute__((unused))
FILE *fopen(const char *pathname, const char *mode)
{
	int flags, fd;

	switch (*mode) {
	case 'r':
		flags = O_RDONLY;
		break;
	case 'w':
		flags = O_WRONLY | O_CREAT | O_TRUNC;
		break;
	case 'a':
		flags = O_WRONLY | O_CREAT | O_APPEND;
		break;
	default:
		SET_ERRNO(EINVAL); return NULL;
	}

	if (mode[1] == '+')
		flags = (flags & ~(O_RDONLY | O_WRONLY)) | O_RDWR;

	fd = open(pathname, flags, 0666);
	return fdopen(fd, mode);
}

/* provides the fd of stream. */
static __attribute__((unused))
int fileno(FILE *stream)
{
	intptr_t i = (intptr_t)stream;

	if (i >= 0) {
		SET_ERRNO(EBADF);
		return -1;
	}
	return ~i;
}

/* flush a stream. */
static __attribute__((unused))
int fflush(FILE *stream)
{
	intptr_t i = (intptr_t)stream;

	/* NULL is valid here. */
	if (i > 0) {
		SET_ERRNO(EBADF);
		return -1;
	}

	/* Don't do anything, nolibc does not support buffering. */
	return 0;
}

/* flush a stream. */
static __attribute__((unused))
int fclose(FILE *stream)
{
	intptr_t i = (intptr_t)stream;

	if (i >= 0) {
		SET_ERRNO(EBADF);
		return -1;
	}

	if (close(~i))
		return EOF;

	return 0;
}

/* getc(), fgetc(), getchar() */

#define getc(stream) fgetc(stream)

static __attribute__((unused))
int fgetc(FILE* stream)
{
	unsigned char ch;

	if (read(fileno(stream), &ch, 1) <= 0)
		return EOF;
	return ch;
}

static __attribute__((unused))
int getchar(void)
{
	return fgetc(stdin);
}


/* putc(), fputc(), putchar() */

#define putc(c, stream) fputc(c, stream)

static __attribute__((unused))
int fputc(int c, FILE* stream)
{
	unsigned char ch = c;

	if (write(fileno(stream), &ch, 1) <= 0)
		return EOF;
	return ch;
}

static __attribute__((unused))
int putchar(int c)
{
	return fputc(c, stdout);
}


/* fwrite(), fread(), puts(), fputs(). Note that puts() emits '\n' but not fputs(). */

/* internal fwrite()-like function which only takes a size and returns 0 on
 * success or EOF on error. It automatically retries on short writes.
 */
static __attribute__((unused))
int _fwrite(const