stdio.h

// Copyright Microsoft and CHERIoT Contributors.
// SPDX-License-Identifier: MIT
 
#ifndef __STDIO_H__
#define __STDIO_H__
 
#include <cdefs.h>
#include <compartment-macros.h>
#include <stdarg.h>
#include <stddef.h>
#include <cheri-builtins.h>
 
#define PRT_MAX_SIZE (0x80)
#define EOF (-1)
 
__BEGIN_DECLS
 
/**
 * This is a very simple implementation of a subset of stdio and supports only
 * UARTs.  The Uart type is often a C++ template type and so we can't forward
 * declare it in a C header and so we use a volatile void* instead, which can
 * be cast to the correct type inside the library.
 */
typedef volatile void FILE;
 
#if DEVICE_EXISTS(uart0)
#   define stdout MMIO_CAPABILITY(void, uart0)
#   define stdin MMIO_CAPABILITY(void, uart0)
#elif DEVICE_EXISTS(uart)
#   define stdout MMIO_CAPABILITY(void, uart)
#   define stdin MMIO_CAPABILITY(void uart)
#else
#error No device found for stdout and stderr
#endif
 
#if DEVICE_EXISTS(uart1) && !STDERR_TO_STDOUT
#   define stderr MMIO_CAPABILITY(void, uart1)
#elif defined(stdout)
#   define stderr stdout
#else
#error No device found for stderr
#endif
 
int __cheri_libcall vfprintf(FILE *stream, const char *fmt, va_list ap);
 
static inline int fprintf(FILE *stream, const char *format, ...)
{
    va_list ap;
 
    va_start(ap, format);
    int ret = vfprintf(stream, format, ap);
    va_end(ap);
    return ret;
}
 
#ifdef stdout
static inline int printf(const char *format, ...)
{
    va_list ap;
 
    va_start(ap, format);
    int ret = vfprintf(stdout, format, ap);
    va_end(ap);
    return ret;
}
#endif
 
int __cheri_libcall snprintf(char *str, size_t size, const char *format, ...);
int __cheri_libcall vsnprintf(char *str,
                              size_t      size,
                              const char *format,
                              va_list     ap);
 
static inline int sprintf(char *str, const char *format, ...)
{
    va_list args;
    va_start(args, format);
    int ret = vsnprintf(str, cheri_top_get(str) - cheri_address_get(str), format, args);
    va_end(args);
    return ret;
}
__END_DECLS
 
#endif /* !__STDIO_H__ */