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1//
2// lconv_unsigned_char_initialization.cpp
3//
4// Copyright (c) Microsoft Corporation. All rights reserved.
5//
6// lconv initialization used to support an unsigned 'char' type (enabled by the
7// -J flag during compilation). Per the specification, some members of the lconv
8// structure must be initialized to CHAR_MAX. The value of CHAR_MAX, however,
9// depends on whether the 'char' type is signed or unsigned (it is 127 for a
10// signed 'char'; 255 for an unsigned 'char').
11//
12// By default, these members of lconv are initialized to SCHAR_MAX (127). If an
13// unsigned 'char' type is used, we call this function to update those members
14// to UCHAR_MAX (255). Note that this is not done for DLLs that are linked to
15// the CRT DLL, because we do not want such DLLs to override the -J setting for
16// an EXE linked to the CRT DLL.
17//
18// There is code in several other files that is required to make all of this work:
19//
20// * locale.h: When -J is used to compile a source file that includes <locale.h>,
21// it generates an unresolved external to __do_unsigned_char_lconv_initialization.
22//
23// * lconv_unsigned_char_static.cpp: This file defines a global variable named
24// __do_unsigned_char_lconv_initialization, and is used during the link to
25// satisfy the unresolved external. This file adds a call to
26// __initialize_lconv_for_unsigned_char to the list of initializers to be
27// executed. That function (defined below) updates the fields of the lconv
28// structure to be set to UCHAR_MAX.
29//
30// * localeconv.cpp: This file defines the __acrt_lconv_c structure.
31//
32#include <corecrt_internal.h>
33#include <limits.h>
34#include <locale.h>
35
36#pragma warning(disable: 4310) // cast truncates constant value
37
38
39
40extern "C" int __cdecl __initialize_lconv_for_unsigned_char()
41{
42 __acrt_lconv_c.int_frac_digits = (char)UCHAR_MAX;
43 __acrt_lconv_c.frac_digits = (char)UCHAR_MAX;
44 __acrt_lconv_c.p_cs_precedes = (char)UCHAR_MAX;
45 __acrt_lconv_c.p_sep_by_space = (char)UCHAR_MAX;
46 __acrt_lconv_c.n_cs_precedes = (char)UCHAR_MAX;
47 __acrt_lconv_c.n_sep_by_space = (char)UCHAR_MAX;
48 __acrt_lconv_c.p_sign_posn = (char)UCHAR_MAX;
49 __acrt_lconv_c.n_sign_posn = (char)UCHAR_MAX;
50
51 return 0;
52}