语法求解~

[Volftooth]

GOPT 的源码、

#define gopt_start(...)  (const void*)( const struct { int k; int f; const char *s; const char*const*l; }[]){ __VA_ARGS__, {0}}
#define gopt_option(k,f,s,l)    { k, f, s, l }

求详解~~看不懂~

[猪头小哥]

你把他们在哪里用到的程序贴出来看看

[Volftooth]

我发详细点吧~

#define gopt_start(...)  (const void*)( const struct { int k; int f; const char *s; const char*const*l; }[]){ __VA_ARGS__, {0}}
#define gopt_option(k,f,s,l)    { k, f, s, l }
#define gopt_shorts( ... )      (const char*)(const char[]){ __VA_ARGS__, 0 }
#define gopt_longs( ... )       (const char**)(const char*[]){ __VA_ARGS__, NULL }
void *options= gopt_sort( & argc, argv, gopt_start(
		gopt_option('h', 0, gopt_shorts('h', '?'), gopt_longs("help", "HELP")),
		gopt_option('v', 0, gopt_shorts('v'), gopt_longs("version")),
		gopt_option('s', GOPT_ARG, gopt_shorts('s'), gopt_longs("secu_flag")),
		gopt_option('c', GOPT_ARG, gopt_shorts('c'), gopt_longs("cid")),
		gopt_option('S', 0, gopt_shorts('S'), gopt_longs("sim_unlock")),
		gopt_option('f', 0, gopt_shorts('f'), gopt_longs("free_all")),
		gopt_option('w', GOPT_ARG, gopt_shorts('w'), gopt_longs("disable_wp")),
		gopt_option('k', GOPT_ARG, gopt_shorts('k'), gopt_longs("disable_kf")),
		gopt_option('b', GOPT_ARG, gopt_shorts('b'), gopt_longs("hboot")),
		gopt_option('r', GOPT_ARG, gopt_shorts('r'), gopt_longs("restore")),
		gopt_option('y', GOPT_ARG, gopt_shorts('y'), gopt_longs("recovery")),
		gopt_option('d', 0, gopt_shorts('d'), gopt_longs("debug"))));

[黯然]

我勒个去...宏定义替换..

[赵4老师]

VS的话，编译选项加/EP /P，重新编译，查看宏展开后对应的.i文件。

[Volftooth]

VS2010 编译不过~

1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): warning C4116: unnamed type definition in parentheses
1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): error C2059: syntax error : '{'

[赵4老师]

[Quote=引用 8 楼 volftooth 的回复:]
VS2010 编译不过~

1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): warning C4116: unnamed type definition in parentheses
1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): error C2059: syntax error : '{'
[/Quote]
将后缀改为.cpp再试试？

[赵4老师]

ms-help://MS.MSDNQTR.v80.chs/MS.MSDN.v80/MS.VisualStudio.v80.chs/dv_vclang/html/51e757dc-0134-4bb2-bb74-64ea5ad75134.htm
C++ Language Reference
Variadic Macros

Variadic macros are function-like macros that contain a variable number of arguments.

Remarks
To use variadic macros, the ellipsis may be specified as the final formal argument in a macro definition, and the replacement identifier __VA_ARGS__ may be used in the definition to insert the extra arguments. __VA_ARGS__ is replaced by all of the arguments that match the ellipsis, including commas between them.

The C Standard specifies that at least one argument must be passed to the ellipsis, to ensure that the macro does not resolve to an expression with a trailing comma. The Visual C++ implementation will suppress a trailing comma if no arguments are passed to the ellipsis.

Example
Copy Code
// variadic_macros.cpp
#include <stdio.h>
#define EMPTY

#define CHECK1(x, ...) if (!(x)) { printf(__VA_ARGS__); }
#define CHECK2(x, ...) if ((x)) { printf(__VA_ARGS__); }
#define CHECK3(...) { printf(__VA_ARGS__); }
#define MACRO(s, ...) printf(s, __VA_ARGS__)

int main() {
CHECK1(0, "here %s %s %s", "are", "some", "varargs1(1)\n");
CHECK1(1, "here %s %s %s", "are", "some", "varargs1(2)\n"); // won't print

CHECK2(0, "here %s %s %s", "are", "some", "varargs2(3)\n"); // won't print
CHECK2(1, "here %s %s %s", "are", "some", "varargs2(4)\n");

// always invokes printf in the macro
CHECK3("here %s %s %s", "are", "some", "varargs3(5)\n");

MACRO("hello, world\n");
// MACRO("error\n", EMPTY); would cause C2059
}


Output

here are some varargs1(1)
here are some varargs2(4)
here are some varargs3(5)
hello, world


See Also
Reference
Macros (C/C++)

[Volftooth]

[Quote=引用 9 楼 zhao4zhong1 的回复:]

引用 8 楼 volftooth 的回复:
VS2010 编译不过~

1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): warning C4116: unnamed type definition in parentheses
1>f:\volftooth's works\pc\sxs\sxs\sxs.c(185): error C2059: ……
[/Quote]

改了错误更多了、

我就想知道 (const void*)( const struct { int k; int f; const char *s; const char*const*l; }[]){ __VA_ARGS__, {0}} 是什么意思？、
结构体还没有名字？、后面的大括号又是什么意思？、

[赵4老师]

偶遇到类似问题都是用
“每次用/*...*/注释掉不同部分再重新编译，直到定位到具体语法出错的位置。”
的方法解决的。

[ccjsj1]

define 宏定义替换

[SDKSC]

貌似在C语言陷阱和缺陷这本书中有些比较像的函数定义········小白路过

[AnYidan]

可变参数的宏

[shangwu_35]

先说中间的部分吧：

定义了 结构体数组的无名变量，维度是2，用__VA_ARGS__可变参列表初始化其中一个结构元素，{0}初始第二个元素。

然后用void* 指针指向这个结构体数组首地址


你调用的时候 void *pvoid = gopt_start（3,3，"string","string1");

实际就是这样 pvoid 指向了这个东西{{3,3,"string","string1"}，{0}}