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/**
* @file stdtypes.h
* @brief Basic type declarations for cross platform compatibility.
*
* $LicenseInfo:firstyear=2000&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_STDTYPES_H
#define LL_STDTYPES_H
#include <cassert>
#include <cfloat>
#include <climits>
#include <cstddef>
#include <limits>
#include <type_traits>
typedef signed char S8;
typedef unsigned char U8;
typedef signed short S16;
typedef unsigned short U16;
typedef signed int S32;
typedef unsigned int U32;
// to express an index that might go negative
// (ssize_t is provided by SOME compilers, don't collide)
typedef typename std::make_signed<std::size_t>::type llssize;
#if LL_WINDOWS
// https://docs.microsoft.com/en-us/cpp/build/reference/zc-wchar-t-wchar-t-is-native-type
// https://docs.microsoft.com/en-us/cpp/cpp/fundamental-types-cpp
// Windows wchar_t is 16-bit, whichever way /Zc:wchar_t is set. In effect,
// Windows wchar_t is always a typedef, either for unsigned short or __wchar_t.
// (__wchar_t, available either way, is Microsoft's native 2-byte wchar_t type.)
// The version of clang available with VS 2019 also defines wchar_t as __wchar_t
// which is also 16 bits.
// In any case, llwchar should be a UTF-32 type.
typedef U32 llwchar;
#else
typedef wchar_t llwchar;
// What we'd actually want is a simple module-scope 'if constexpr' to test
// std::is_same<wchar_t, llwchar>::value and use that to define, or not
// define, string conversion specializations. Since we don't have that, we'll
// have to rely on #if instead. Sorry, Dr. Stroustrup.
#define LLWCHAR_IS_WCHAR_T 1
#endif
#if LL_WINDOWS
typedef signed __int64 S64;
// probably should be 'hyper' or similiar
#define S64L(a) (a)
typedef unsigned __int64 U64;
#define U64L(a) (a)
#else
typedef long long int S64;
typedef long long unsigned int U64;
#if LL_DARWIN || LL_LINUX || LL_FREEBSD
#define S64L(a) (a##LL)
#define U64L(a) (a##ULL)
#endif
#endif
typedef float F32;
typedef double F64;
typedef S32 BOOL;
typedef U8 KEY;
typedef U32 MASK;
typedef U32 TPACKETID;
// Use #define instead of consts to avoid conversion headaches
#define S8_MAX (SCHAR_MAX)
#define U8_MAX (UCHAR_MAX)
#define S16_MAX (SHRT_MAX)
#define U16_MAX (USHRT_MAX)
#define S32_MAX (INT_MAX)
#define U32_MAX (UINT_MAX)
#define F32_MAX (FLT_MAX)
#define F64_MAX (DBL_MAX)
#define S8_MIN (SCHAR_MIN)
#define U8_MIN (0)
#define S16_MIN (SHRT_MIN)
#define U16_MIN (0)
#define S32_MIN (INT_MIN)
#define U32_MIN (0)
#define F32_MIN (FLT_MIN)
#define F64_MIN (DBL_MIN)
#ifndef TRUE
#define TRUE (1)
#endif
#ifndef FALSE
#define FALSE (0)
#endif
#if LL_FREEBSD
#undef NULL
#endif
#ifndef NULL
#define NULL (0)
#endif
typedef U8 LLPCode;
#define LL_ARRAY_SIZE( _kArray ) ( sizeof( (_kArray) ) / sizeof( _kArray[0] ) )
#if LL_LINUX && __GNUC__ <= 2
typedef int intptr_t;
#endif
/*****************************************************************************
* Narrowing
*****************************************************************************/
/**
* narrow() is used to cast a wider type to a narrower type with validation.
*
* In many cases we take the size() of a container and try to pass it to an
* S32 or a U32 parameter. We used to be able to assume that the size of
* anything we could fit into memory could be expressed as a 32-bit int. With
* 64-bit viewers, though, size_t as returned by size() and length() and so
* forth is 64 bits, and the compiler is unhappy about stuffing such values
* into 32-bit types.
*
* It works to force the compiler to truncate, e.g. static_cast<S32>(len) or
* S32(len) or (S32)len, but we can do better.
*
* For:
* @code
* std::vector<Object> container;
* void somefunc(S32 size);
* @endcode
* call:
* @code
* somefunc(narrow(container.size()));
* @endcode
*
* narrow() truncates but, in RelWithDebInfo builds, it validates (using
* assert()) that the passed value can validly be expressed by the destination
* type.
*/
// narrow_holder is a struct that accepts the passed value as its original
// type and provides templated conversion functions to other types. Once we're
// building with compilers that support Class Template Argument Deduction, we
// can rename this class template 'narrow' and eliminate the narrow() factory
// function below.
template <typename FROM>
class narrow_holder
{
private:
FROM mValue;
public:
narrow_holder(FROM value): mValue(value) {}
/*---------------------- Narrowing unsigned to signed ----------------------*/
template <typename TO,
typename std::enable_if<std::is_unsigned<FROM>::value &&
std::is_signed<TO>::value,
bool>::type = true>
inline
operator TO() const
{
// The reason we skip the
// assert(value >= std::numeric_limits<TO>::lowest());
// like the overload below is that to perform the above comparison,
// the compiler promotes the signed lowest() to the unsigned FROM
// type, making it hugely positive -- so a reasonable 'value' will
// always fail the assert().
assert(mValue <= std::numeric_limits<TO>::max());
return static_cast<TO>(mValue);
}
/*----------------------- Narrowing all other cases ------------------------*/
template <typename TO,
typename std::enable_if<! (std::is_unsigned<FROM>::value &&
std::is_signed<TO>::value),
bool>::type = true>
inline
operator TO() const
{
// two different assert()s so we can tell which condition failed
assert(mValue <= std::numeric_limits<TO>::max());
// Funny, with floating point types min() is "positive epsilon" rather
// than "largest negative" -- that's lowest().
assert(mValue >= std::numeric_limits<TO>::lowest());
// Do we really expect to use this with floating point types?
// If so, does it matter if a very small value truncates to zero?
//assert(fabs(mValue) >= std::numeric_limits<TO>::min());
return static_cast<TO>(mValue);
}
};
/// narrow() factory function returns a narrow_holder<FROM>(), which can be
/// implicitly converted to the target type.
template <typename FROM>
inline
narrow_holder<FROM> narrow(FROM value)
{
return { value };
}
#endif
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