gcc/libcc1/rpc.hh
Tom Tromey 0f237df286 libcc1: add more uses of 'deleter'
This changes libcc1 to use the 'deleter' template in a few more
places.  The template and basic specializations are moved to a new
header, then some unmarshall functions are changed to use this code.
This change avoids the need to repeat cleanup code in the
unmarshallers.

libcc1

	* rpc.hh (deleter): Move template and some specializations to
	deleter.hh.
	(argument_wrapper<const T *>): Use cc1_plugin::unique_ptr.
	* marshall.cc (cc1_plugin::unmarshall): Use
	cc1_plugin::unique_ptr.
	* marshall-cp.hh (deleter): New specializations.
	(unmarshall): Use cc1_plugin::unique_ptr.
	* deleter.hh: New file.
2021-05-05 00:06:17 -06:00

298 lines
7.7 KiB
C++

/* RPC call and callback templates
Copyright (C) 2014-2021 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef CC1_PLUGIN_RPC_HH
#define CC1_PLUGIN_RPC_HH
#include "status.hh"
#include "connection.hh"
#include "deleter.hh"
namespace cc1_plugin
{
// The plugin API may contain some "const" method parameters.
// However, when unmarshalling we cannot unmarshall into a const
// object; and furthermore we want to be able to deallocate pointers
// when finished with them. This wrapper class lets us properly
// remove the "const" and handle deallocation from pointer types.
template<typename T>
class argument_wrapper
{
public:
argument_wrapper () { }
~argument_wrapper () { }
argument_wrapper (const argument_wrapper &) = delete;
argument_wrapper &operator= (const argument_wrapper &) = delete;
operator T () const { return m_object; }
status unmarshall (connection *conn)
{
return ::cc1_plugin::unmarshall (conn, &m_object);
}
private:
T m_object;
};
// Specialization for any kind of pointer.
template<typename T>
class argument_wrapper<T *>
{
public:
argument_wrapper () = default;
~argument_wrapper () = default;
argument_wrapper (const argument_wrapper &) = delete;
argument_wrapper &operator= (const argument_wrapper &) = delete;
typedef typename std::remove_const<T>::type type;
operator const type * () const
{
return m_object.get ();
}
status unmarshall (connection *conn)
{
type *ptr;
if (!::cc1_plugin::unmarshall (conn, &ptr))
return FAIL;
m_object.reset (ptr);
return OK;
}
private:
unique_ptr<type> m_object;
};
// There are two kinds of template functions here: "call" and
// "callback". "call" is implemented with variadic templates, but
// "callback" is repeated multiple times to handle different numbers
// of arguments. (This could be improved with C++17 and
// std::apply.)
// The "call" template is used for making a remote procedure call.
// It starts a query ('Q') packet, marshalls its arguments, waits
// for a result, and finally reads and returns the result via an
// "out" parameter.
// The "callback" template is used when receiving a remote procedure
// call. This template function is suitable for use with the
// "callbacks" and "connection" classes. It decodes incoming
// arguments, passes them to the wrapped function, and finally
// marshalls a reply packet.
template<typename R, typename... Arg>
status
call (connection *conn, const char *method, R *result, Arg... args)
{
if (!conn->send ('Q'))
return FAIL;
if (!marshall (conn, method))
return FAIL;
if (!marshall (conn, (int) sizeof... (Arg)))
return FAIL;
if (!marshall (conn, args...))
return FAIL;
if (!conn->wait_for_result ())
return FAIL;
if (!unmarshall (conn, result))
return FAIL;
return OK;
}
template<typename R, R (*func) (connection *)>
status
callback (connection *conn)
{
R result;
if (!unmarshall_check (conn, 0))
return FAIL;
result = func (conn);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A, R (*func) (connection *, A)>
status
callback (connection *conn)
{
argument_wrapper<A> arg;
R result;
if (!unmarshall_check (conn, 1))
return FAIL;
if (!arg.unmarshall (conn))
return FAIL;
result = func (conn, arg);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A1, typename A2, R (*func) (connection *,
A1, A2)>
status
callback (connection *conn)
{
argument_wrapper<A1> arg1;
argument_wrapper<A2> arg2;
R result;
if (!unmarshall_check (conn, 2))
return FAIL;
if (!arg1.unmarshall (conn))
return FAIL;
if (!arg2.unmarshall (conn))
return FAIL;
result = func (conn, arg1, arg2);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A1, typename A2, typename A3,
R (*func) (connection *, A1, A2, A3)>
status
callback (connection *conn)
{
argument_wrapper<A1> arg1;
argument_wrapper<A2> arg2;
argument_wrapper<A3> arg3;
R result;
if (!unmarshall_check (conn, 3))
return FAIL;
if (!arg1.unmarshall (conn))
return FAIL;
if (!arg2.unmarshall (conn))
return FAIL;
if (!arg3.unmarshall (conn))
return FAIL;
result = func (conn, arg1, arg2, arg3);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A1, typename A2, typename A3, typename A4,
R (*func) (connection *, A1, A2, A3, A4)>
status
callback (connection *conn)
{
argument_wrapper<A1> arg1;
argument_wrapper<A2> arg2;
argument_wrapper<A3> arg3;
argument_wrapper<A4> arg4;
R result;
if (!unmarshall_check (conn, 4))
return FAIL;
if (!arg1.unmarshall (conn))
return FAIL;
if (!arg2.unmarshall (conn))
return FAIL;
if (!arg3.unmarshall (conn))
return FAIL;
if (!arg4.unmarshall (conn))
return FAIL;
result = func (conn, arg1, arg2, arg3, arg4);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A1, typename A2, typename A3, typename A4,
typename A5, R (*func) (connection *, A1, A2, A3, A4, A5)>
status
callback (connection *conn)
{
argument_wrapper<A1> arg1;
argument_wrapper<A2> arg2;
argument_wrapper<A3> arg3;
argument_wrapper<A4> arg4;
argument_wrapper<A5> arg5;
R result;
if (!unmarshall_check (conn, 5))
return FAIL;
if (!arg1.unmarshall (conn))
return FAIL;
if (!arg2.unmarshall (conn))
return FAIL;
if (!arg3.unmarshall (conn))
return FAIL;
if (!arg4.unmarshall (conn))
return FAIL;
if (!arg5.unmarshall (conn))
return FAIL;
result = func (conn, arg1, arg2, arg3, arg4, arg5);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
template<typename R, typename A1, typename A2, typename A3, typename A4,
typename A5, typename A6, typename A7,
R (*func) (connection *, A1, A2, A3, A4, A5, A6, A7)>
status
callback (connection *conn)
{
argument_wrapper<A1> arg1;
argument_wrapper<A2> arg2;
argument_wrapper<A3> arg3;
argument_wrapper<A4> arg4;
argument_wrapper<A5> arg5;
argument_wrapper<A6> arg6;
argument_wrapper<A7> arg7;
R result;
if (!unmarshall_check (conn, 7))
return FAIL;
if (!arg1.unmarshall (conn))
return FAIL;
if (!arg2.unmarshall (conn))
return FAIL;
if (!arg3.unmarshall (conn))
return FAIL;
if (!arg4.unmarshall (conn))
return FAIL;
if (!arg5.unmarshall (conn))
return FAIL;
if (!arg6.unmarshall (conn))
return FAIL;
if (!arg7.unmarshall (conn))
return FAIL;
result = func (conn, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
if (!conn->send ('R'))
return FAIL;
return marshall (conn, result);
}
};
#endif // CC1_PLUGIN_RPC_HH