1/* Internal errno names mapping definition.
2 Copyright (C) 2022-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <stdio.h>
20#include <errno.h>
21#include <libintl.h>
22#include <array_length.h>
23
24#ifndef ERR_MAP
25# define ERR_MAP(n) n
26#endif
27
28static const union sys_errname_t
29{
30 struct
31 {
32#define MSGSTRFIELD1(line) str##line
33#define MSGSTRFIELD(line) MSGSTRFIELD1(line)
34#define _S(n, str) char MSGSTRFIELD(__LINE__)[sizeof(#n)];
35#include <errlist.h>
36#undef _S
37 };
38 char str[0];
39} _sys_errname = { {
40#define _S(n, s) #n,
41#include <errlist.h>
42#undef _S
43} };
44
45static const unsigned short _sys_errnameidx[] =
46{
47#define _S(n, s) \
48 [ERR_MAP(n)] = offsetof(union sys_errname_t, MSGSTRFIELD(__LINE__)),
49#include <errlist.h>
50#undef _S
51};
52
53const char *
54__get_errname (int errnum)
55{
56 int mapped = ERR_MAP (errnum);
57 if (mapped < 0 || mapped >= array_length (_sys_errnameidx)
58 || (mapped > 0 && _sys_errnameidx[mapped] == 0))
59 return NULL;
60 return _sys_errname.str + _sys_errnameidx[mapped];
61}
62

source code of glibc/stdio-common/errname.c