我怎么称呼这些封装器呢，它们好像是数组之类的东西，我很困惑
static auto w_printf = [](const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vprintf_s(fmt, args);
va_end(args);
};
static auto w_printf_s = [](const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vprintf_s(fmt, args);
va_end(args);
};
static auto w_sprintf = [](char* buf, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vsprintf(buf, fmt, args);
va_end(args);
};
static auto w_sprintf_s = [](char* buf, size_t buf_size, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vsprintf_s(buf, buf_size, fmt, args);
va_end(args);
};
我试过了
char mytext[255] = { 0 };
//sprintf_s(mytext, "old [debug mode]");
w_sprintf(mytext, XorStr("new [debug mode]"));
但却无法编译
Error C3861 'w_sprintf': identifier not found
它说我必须使用这些包装器，因为在sprintf_s中使用XorStr宏会使Visual Studio 2015中的链接器崩溃关于Microsoft CompilerLinker的一些东西不能正确地与变量模板一起工作，这些包装器函数应该解决这个问题，但我不知道如何调用它们。
我试图在编译时将字符串从汇编中隐藏起来，到目前为止效果还不错，但某些东西像 sprintf_s 崩溃，这个编译时字符串隐藏器的创建者说我需要使用这些包装器，但没有给出任何例子。
#pragma once
#include <string>
#include <array>
#include <cstdarg>
#define BEGIN_NAMESPACE( x ) namespace x {
#define END_NAMESPACE }
BEGIN_NAMESPACE(XorCompileTime)
constexpr auto time = __TIME__;
constexpr auto seed = static_cast< int >(time[7]) + static_cast< int >(time[6]) * 10 + static_cast< int >(time[4]) * 60 + static_cast< int >(time[3]) * 600 + static_cast< int >(time[1]) * 3600 + static_cast< int >(time[0]) * 36000;
// 1988, Stephen Park and Keith Miller
// "Random Number Generators: Good Ones Are Hard To Find", considered as "minimal standard"
// Park-Miller 31 bit pseudo-random number generator, implemented with G. Carta's optimisation:
// with 32-bit math and without division
template < int N >
struct RandomGenerator
{
private:
static constexpr unsigned a = 16807; // 7^5
static constexpr unsigned m = 2147483647; // 2^31 - 1
static constexpr unsigned s = RandomGenerator< N - 1 >::value;
static constexpr unsigned lo = a * (s & 0xFFFF); // Multiply lower 16 bits by 16807
static constexpr unsigned hi = a * (s >> 16); // Multiply higher 16 bits by 16807
static constexpr unsigned lo2 = lo + ((hi & 0x7FFF) << 16); // Combine lower 15 bits of hi with lo's upper bits
static constexpr unsigned hi2 = hi >> 15; // Discard lower 15 bits of hi
static constexpr unsigned lo3 = lo2 + hi;
public:
static constexpr unsigned max = m;
static constexpr unsigned value = lo3 > m ? lo3 - m : lo3;
};
template <>
struct RandomGenerator< 0 >
{
static constexpr unsigned value = seed;
};
template < int N, int M >
struct RandomInt
{
static constexpr auto value = RandomGenerator< N + 1 >::value % M;
};
template < int N >
struct RandomChar
{
static const char value = static_cast< char >(1 + RandomInt< N, 0x7F - 1 >::value);
};
template < size_t N, int K, typename Char >
struct XorString
{
private:
const char _key;
std::array< Char, N + 1 > _encrypted;
constexpr Char enc(Char c) const
{
return c ^ _key;
}
Char dec(Char c) const
{
return c ^ _key;
}
public:
template < size_t... Is >
constexpr __forceinline XorString(const Char* str, std::index_sequence< Is... >) : _key(RandomChar< K >::value), _encrypted{ enc(str[Is])... }
{
}
__forceinline decltype(auto) decrypt(void)
{
for (size_t i = 0; i < N; ++i) {
_encrypted[i] = dec(_encrypted[i]);
}
_encrypted[N] = '\0';
return _encrypted.data();
}
};
//--------------------------------------------------------------------------------
//-- Note: XorStr will __NOT__ work directly with functions like printf.
// To work with them you need a wrapper function that takes a const char*
// as parameter and passes it to printf and alike.
//
// The Microsoft Compiler/Linker is not working correctly with variadic
// templates!
//
// Use the functions below or use std::cout (and similar)!
//--------------------------------------------------------------------------------
static auto w_printf = [](const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vprintf_s(fmt, args);
va_end(args);
};
static auto w_printf_s = [](const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vprintf_s(fmt, args);
va_end(args);
};
static auto w_sprintf = [](char* buf, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vsprintf(buf, fmt, args);
va_end(args);
};
static auto w_sprintf_ret = [](char* buf, const char* fmt, ...) {
int ret;
va_list args;
va_start(args, fmt);
ret = vsprintf(buf, fmt, args);
va_end(args);
return ret;
};
static auto w_sprintf_s = [](char* buf, size_t buf_size, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
vsprintf_s(buf, buf_size, fmt, args);
va_end(args);
};
static auto w_sprintf_s_ret = [](char* buf, size_t buf_size, const char* fmt, ...) {
int ret;
va_list args;
va_start(args, fmt);
ret = vsprintf_s(buf, buf_size, fmt, args);
va_end(args);
return ret;
};
//Old functions before I found out about wrapper functions.
//#define XorStr( s ) ( XorCompileTime::XorString< sizeof(s)/sizeof(char) - 1, __COUNTER__, char >( s, std::make_index_sequence< sizeof(s)/sizeof(char) - 1>() ).decrypt() )
//#define XorStrW( s ) ( XorCompileTime::XorString< sizeof(s)/sizeof(wchar_t) - 1, __COUNTER__, wchar_t >( s, std::make_index_sequence< sizeof(s)/sizeof(wchar_t) - 1>() ).decrypt() )
//Wrapper functions to work in all functions below
#define XorStr( s ) []{ constexpr XorCompileTime::XorString< sizeof(s)/sizeof(char) - 1, __COUNTER__, char > expr( s, std::make_index_sequence< sizeof(s)/sizeof(char) - 1>() ); return expr; }().decrypt()
#define XorStrW( s ) []{ constexpr XorCompileTime::XorString< sizeof(s)/sizeof(wchar_t) - 1, __COUNTER__, wchar_t > expr( s, std::make_index_sequence< sizeof(s)/sizeof(wchar_t) - 1>() ); return expr; }().decrypt()
END_NAMESPACE
D'oh，我错过了命名空间，嘿嘿。
char mytext[255] = { 0 };
//sprintf_s(mytext, "old [debug mode]");
XorCompileTime::w_sprintf(mytext, XorStr("new [debug mode]"));