genode/repos/ports/include/vmm/printf.h
Norman Feske 17c79a9e23 base: avoid use of deprecated base/printf.h
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.

While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).

To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.

Issue #1987
2016-08-29 17:27:10 +02:00

51 lines
1007 B
C++

/*
* \brief Utilities for implementing VMMs on Genode/NOVA
* \author Norman Feske
* \date 2013-08-20
*/
/*
* Copyright (C) 2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__VMM__PRINTF_H_
#define _INCLUDE__VMM__PRINTF_H_
/* Genode includes */
#include <base/thread.h>
#include <base/lock.h>
#include <base/log.h>
/* NOVA includes */
#include <nova/syscalls.h>
namespace Vmm {
using namespace Genode;
/**
* Print message while preserving the UTCB content
*/
template <typename... ARGS>
void log(ARGS... args)
{
struct Utcb_backup { char buf[Nova::Utcb::size()]; };
static Lock lock;
static Utcb_backup utcb_backup;
Lock::Guard guard(lock);
utcb_backup = *(Utcb_backup *)Thread::myself()->utcb();
Genode::log("VMM: ", args...);
*(Utcb_backup *)Thread::myself()->utcb() = utcb_backup;
}
}
#endif /* _INCLUDE__VMM__PRINTF_H_ */