extended_cstring.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2024 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */
 
 
 
/** @defgroup extended_cstring
 *  @brief extra functions for plain old C strings
 *  @author Bram de Greve [BdG]
 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_STDE_EXTENDED_CSTRING_H
#define LASS_GUARDIAN_OF_INCLUSION_STDE_EXTENDED_CSTRING_H
 
#include "stde_common.h"
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
 
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
#   pragma warning(push)
#   pragma warning(disable: 4996) // 'vsnprintf': This function or variable may be unsafe.
#endif
 
// Forwarding va_list arguments to vsnprintf will cause Clang to complain about not being able 
// to check the arguments passed to vsnprintf.  To remedy, we need to tell the compiler that 
// the wrapper function's arguments also need to be checked to be compliant with the sprintf formats.
// If this works, we might move this to a more permanent location.
#if LASS_COMPILER_TYPE == LASS_COMPILER_TYPE_GCC || LASS_COMPILER_TYPE == LASS_COMPILER_TYPE_CLANG
#   define LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(archetype, string_index, first_to_check) __attribute__ ((format (archetype, string_index, first_to_check)))
#else
#   define LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(archetype, string_index, first_to_check)
#endif
 
namespace lass
{
namespace stde
{
 
template <int N> int safe_vsprintf(char(&buffer)[N], const char* format, va_list args) LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(printf, 2, 0);
template <int N> int safe_sprintf(char(&buffer)[N], const char* format, ...) LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(printf, 2, 3);
 
template <int N>
int safe_vsprintf(char (&buffer)[N], const char* format, va_list args)
{
    const int numWritten = ::vsnprintf(buffer, N, format, args);
    if (numWritten < 0)
    {
        throw std::runtime_error("safe_vformat: encoding error");
    }
    if (numWritten >= N)
    {
        throw std::length_error("safe_vsprintf: buffer overflow.");
    }
    buffer[N - 1] = 0;
    return numWritten;
}
 
template <int N>
int safe_sprintf(char (& buffer)[N], const char* format, ...)
{
    va_list args;
    va_start(args, format);
    const int numWritten = safe_vsprintf(buffer, format, args);
    va_end(args);
    return numWritten;
}
 
template <size_t N>
char* safe_strcat(char (&buffer)[N], const char* source)
{
    if (strlen(buffer) + strlen(source) >= N)
    {
        throw std::length_error("safe_strcat: buffer overflow");
    }
    return strcat(buffer, source);
}
 
template <size_t N>
char* safe_strcpy(char (&buffer)[N], const char* source)
{
    if (strlen(source) >= N)
    {
        throw std::length_error("safe_strcpy: buffer overflow");
    }
    return strcpy(buffer, source);
}
 
LASS_DLL std::string LASS_CALL safe_vformat(const char* format, va_list args) LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(printf, 1, 0);
LASS_DLL std::string LASS_CALL safe_format(const char* format, ...) LASS_EXPERIMENTAL_ATTRIBUTE_FORMAT(printf, 1, 2);
 
}
}
 
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
#   pragma warning(pop)
#endif
 
#endif
 
// EOF