1/* Marshalling and unmarshalling.
2 Copyright (C) 2014-2025 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3. If not see
18<http://www.gnu.org/licenses/>. */
19
20#ifndef CC1_PLUGIN_MARSHALL_HH
21#define CC1_PLUGIN_MARSHALL_HH
22
23#include <type_traits>
24
25#include "status.hh"
26#include "gcc-interface.h"
27
28namespace cc1_plugin
29{
30 class connection;
31
32 // Only a single kind of integer is ever sent over the wire, and
33 // this is it.
34 typedef unsigned long long protocol_int;
35
36 // Read an integer from the connection and verify that it has the
37 // value V.
38 status unmarshall_check (connection *, protocol_int v);
39
40 // Write an integer, prefixed with the integer type marker, to the
41 // connection.
42 status marshall_intlike (connection *, protocol_int);
43
44 // Read a type marker from the connection and verify that it is an
45 // integer type marker. If not, return FAIL. If so, read an
46 // integer store it in the out argument.
47 status unmarshall_intlike (connection *, protocol_int *);
48
49 status marshall_array_start (connection *, char, size_t);
50 status marshall_array_elmts (connection *, size_t, void *);
51
52 status unmarshall_array_start (connection *, char, size_t *);
53 status unmarshall_array_elmts (connection *, size_t, void *);
54
55 // An "empty" marshall call -- used to handle the base case for some
56 // variadic templates.
57 static inline
58 status marshall (connection *)
59 {
60 return OK;
61 }
62
63 // A template function that can handle marshalling various integer
64 // objects to the connection.
65 template<typename T>
66 status marshall (connection *conn, T scalar)
67 {
68 return marshall_intlike (conn, scalar);
69 }
70
71 // A template function that can handle unmarshalling various integer
72 // objects from the connection. Note that there's no way at the
73 // protocol level to distinguish different int types.
74 template<typename T>
75 status unmarshall (connection *conn, T *scalar,
76 typename std::enable_if<std::is_integral<T>::value, T>::type * = 0)
77 {
78 protocol_int result;
79
80 if (!unmarshall_intlike (conn, &result))
81 return FAIL;
82 *scalar = (T) result;
83 return OK;
84 }
85
86 // A template function that can handle unmarshalling various enum
87 // objects from the connection.
88 template<typename T>
89 status unmarshall (connection *conn, T *e_val,
90 typename std::enable_if<std::is_enum<T>::value, T>::type * = 0)
91 {
92 protocol_int result;
93
94 if (!unmarshall_intlike (conn, &result))
95 return FAIL;
96 *e_val = (T) result;
97 return OK;
98 }
99
100 // Send a string type marker followed by a string.
101 status marshall (connection *, const char *);
102
103 // Read a string type marker followed by a string. The caller is
104 // responsible for freeing the resulting string using 'delete[]'.
105 status unmarshall (connection *, char **);
106
107 // Send a gcc_type_array marker followed by the array.
108 status marshall (connection *, const gcc_type_array *);
109
110 // Read a gcc_type_array marker, followed by a gcc_type_array. The
111 // resulting array must be freed by the caller, using 'delete[]' on
112 // the elements, and 'delete' on the array object itself.
113 status unmarshall (connection *, struct gcc_type_array **);
114
115 template<typename T1, typename T2, typename... Arg>
116 status marshall (connection *c, T1 arg1, T2 arg2, Arg... rest)
117 {
118 if (!marshall (c, arg1))
119 return FAIL;
120 return marshall (c, arg2, rest...);
121 }
122};
123
124#endif // CC1_PLUGIN_MARSHALL_HH
125

source code of libcc1/marshall.hh