__stdcall 和 __cdecl 的区别

[kingtsui]

能否说的详细点

[tlovexyj]

The __stdcall calling convention is used to call Win32 API functions. The callee cleans the stack, so the compiler makes vararg functions __cdecl. Functions that use this calling convention require a function prototype. The following list shows the implementation of this calling convention.

Element Implementation
Argument-passing order Right to left.
Argument-passing convention By value, unless a pointer or reference type is passed.
Stack-maintenance responsibility Called function pops its own arguments from the stack.
Name-decoration convention An underscore (_) is prefixed to the name. The name is followed by the at sign (@) followed by the number of bytes (in decimal) in the argument list. Therefore, the function declared as int func( int a, double b ) is decorated as follows: _func@12
Case-translation convention None


The /Gz compiler option specifies __stdcall for all functions not explicitly declared with a different calling convention.

Functions declared using the __stdcall modifier return values the same way as functions declared using __cdecl.

END Microsoft Specific

Example
In the following example, use of __stdcall results in all WINAPI function types being handled as a standard call:

// Example of the __stdcall keyword
#define WINAPI __stdcall

[lazyeric]

我在这里用了某位大侠的话：
_cdecl
C/C++的缺省调用协定，由调用者清理堆栈，这就是C/C++中可以使
用可变参数的函数的原因，所有参数自右至左入栈，生成的代码中
函数名有一个_(下划线)作前缀。
_stdcall
Win32 API的调用协定，由被调用的函数清理堆栈，所有参数自右至
左入栈，生成的代码中函数名有一个_(下划线)作前缀一个@和参数总
字节数(十进制)作後缀。它不支持可变参数，但它产生的代码比
_cdecl的短，因为没有每次调用後的清理堆栈的代码。

[tlovexyj]

This is the default calling convention for C and C++ programs. Because the stack is cleaned up by the caller, it can do vararg functions. The __cdecl calling convention creates larger executables than __stdcall, because it requires each function call to include stack cleanup code. The following list shows the implementation of this calling convention.

Element Implementation
Argument-passing order Right to left
Stack-maintenance responsibility Calling function pops the arguments from the stack
Name-decoration convention Underscore character (_) is prefixed to names
Case-translation convention No case translation performed


Note For related information, see Decorated Names.

Place the __cdecl modifier before a variable or a function name. Because the C naming and calling conventions are the default, the only time you need to use __cdecl is when you have specified the /Gz (stdcall) or /Gr (fastcall) compiler option. The /Gd compiler option forces the __cdecl calling convention.

Example
In the following example, the compiler is instructed to use C naming and calling conventions for the system function:

// Example of the __cdecl keyword
_CRTIMP int __cdecl system(const char *);

[kingtsui]

__stdcall不需要清栈吗？

[liu_feng_fly]

在你的代码里不用考虑这些事情的！

[kingtsui]

需不需要是一回事，怎么实现是另一回事
我可没有问需不需要啊！

函数调用怎么可能不清栈呢？

[taolei]

kingtsui:
被调用函数在返回时直接清栈。
例如：
ret 10h

就表示该函数有4个参数，返回后ESP再加16个byte.