gecko/mfbt/IntegerPrintfMacros.h
2011-12-15 00:27:42 -05:00

41 lines
1.5 KiB
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Implements the C99 <inttypes.h> interface, minus the SCN* format macros. */
#ifndef mozilla_IntegerPrintfMacros_h_
#define mozilla_IntegerPrintfMacros_h_
/*
* MSVC++ doesn't include <inttypes.h>, even in versions shipping <stdint.h>, so
* we have to reimplement it there. Note: <inttypes.h> #includes <stdint.h>.
*
* Note that this header DOES NOT implement <inttypes.h>'s scanf macros. MSVC's
* scanf doesn't have sufficient format specifier support to implement them
* (specifically, to implement scanning into an 8-bit location).
*
* http://stackoverflow.com/questions/3036396/scanfd-char-char-as-int-format-string
*
* Moreover, scanf is a footgun: if the input number exceeds the bounds of the
* target type, behavior is undefined (in the compiler sense: that is, this code
* could overwrite your hard drive with zeroes):
*
* uint8_t u;
* sscanf("256", "%" SCNu8, &u); // BAD
*
* This header will sometimes provide SCN* macros, by dint of being implemented
* using <inttypes.h>. But for these reasons, *never* use them!
*/
#if defined(MOZ_CUSTOM_INTTYPES_H)
# include MOZ_CUSTOM_INTTYPES_H
#elif defined(_MSC_VER)
# include "mozilla/MSIntTypes.h"
#else
# include <inttypes.h>
#endif
#endif /* mozilla_IntegerPrintfMacros_h_ */