// // lconv_unsigned_char_initialization.cpp // // Copyright (c) Microsoft Corporation. All rights reserved. // // lconv initialization used to support an unsigned 'char' type (enabled by the // -J flag during compilation). Per the specification, some members of the lconv // structure must be initialized to CHAR_MAX. The value of CHAR_MAX, however, // depends on whether the 'char' type is signed or unsigned (it is 127 for a // signed 'char'; 255 for an unsigned 'char'). // // By default, these members of lconv are initialized to SCHAR_MAX (127). If an // unsigned 'char' type is used, we call this function to update those members // to UCHAR_MAX (255). Note that this is not done for DLLs that are linked to // the CRT DLL, because we do not want such DLLs to override the -J setting for // an EXE linked to the CRT DLL. // // There is code in several other files that is required to make all of this work: // // * locale.h: When -J is used to compile a source file that includes , // it generates an unresolved external to __do_unsigned_char_lconv_initialization. // // * lconv_unsigned_char_static.cpp: This file defines a global variable named // __do_unsigned_char_lconv_initialization, and is used during the link to // satisfy the unresolved external. This file adds a call to // __initialize_lconv_for_unsigned_char to the list of initializers to be // executed. That function (defined below) updates the fields of the lconv // structure to be set to UCHAR_MAX. // // * localeconv.cpp: This file defines the __acrt_lconv_c structure. // #include #include #include #pragma warning(disable: 4310) // cast truncates constant value extern "C" int __cdecl __initialize_lconv_for_unsigned_char() { __acrt_lconv_c.int_frac_digits = (char)UCHAR_MAX; __acrt_lconv_c.frac_digits = (char)UCHAR_MAX; __acrt_lconv_c.p_cs_precedes = (char)UCHAR_MAX; __acrt_lconv_c.p_sep_by_space = (char)UCHAR_MAX; __acrt_lconv_c.n_cs_precedes = (char)UCHAR_MAX; __acrt_lconv_c.n_sep_by_space = (char)UCHAR_MAX; __acrt_lconv_c.p_sign_posn = (char)UCHAR_MAX; __acrt_lconv_c.n_sign_posn = (char)UCHAR_MAX; return 0; }