在MinGW的使用scriptedmain麻烦

问题描述

我想重现，捆绑API和CLI在相同的C源$ C ​​$ C文件（）。这是用Python完成与如果__name __ ==__ main__：主（）并在gcc / Unix下，这看起来像：

I want to reproduce this Perl code in C, bundling API and CLI in the same C source code file (scriptedmain). This is done in Python with if __name__=="__main__": main() and in gcc/Unix, this looks like:

$ gcc -o scriptedmain scriptedmain.c scriptedmain.h
$ ./scriptedmain
Main: The meaning of life is 42
$ gcc -o test test.c scriptedmain.c scriptedmain.h
$ ./test
Test: The meaning of life is 42

scriptedmain.h

scriptedmain.h

int meaning_of_life();

scriptedmain.c

scriptedmain.c

#include <stdio.h>

int meaning_of_life() {
    return 42;
}

int __attribute__((weak)) main() {
    printf("Main: The meaning of life is %d\n", meaning_of_life());

    return 0;
}

test.c的

test.c

#include "scriptedmain.h"
#include <stdio.h>

extern int meaning_of_life();

int main() {
    printf("Test: The meaning of life is %d\n", meaning_of_life());
    return 0;
}

然而，当我尝试用gcc /草莓编译，我得到：

However, when I try to compile with gcc/Strawberry, I get:

C:\>gcc -o scriptedmain scriptedmain.c scriptedmain.h
c:/strawberry/c/bin/../lib/gcc/i686-w64-mingw32/4.4.3/../../../../i686-w64-mingw32/lib/libmingw32.a(lib32_libmingw32_a-crt0_c.o): In function `main':
/opt/W64_156151-src.32/build-crt/../mingw-w64-crt/crt/crt0_c.c:18: undefined reference to `WinMain@16'
collect2: ld returned 1 exit status

当我尝试用gcc / MinGW的编译，我得到：

And when I try to compile with gcc/MinGW, I get:

$ gcc -o scriptedmain -mwindows scriptedmain.c scriptedmain.h
c:/mingw/bin/../lib/gcc/mingw32/4.5.2/../../../libmingw32.a(main.o):main.c:(.text+0x104): undefined reference to `WinMain@16'
collect2: ld returned 1 exit status

我怎样才能获得GCC在Windows中识别 __ __属性（（弱））语法？

此外，G ++显示了同样的错误。

Also, G++ shows the same error.

推荐答案

我发现，在Windows和Unix的有效的解决方案：简单包装的main（） $ p中$ pprocessor指令忽略它，除非明确的编译器设置标志。

I found a solution that works in Windows and in Unix: Simply wrap main() in preprocessor instructions that omits it unless explicit compiler flags are set.

scriptedmain.c：

scriptedmain.c:

#include <stdio.h>

int meaning_of_life() {
    return 42;
}

#ifdef SCRIPTEDMAIN

int main() {
    printf("Main: The meaning of life is %d\n", meaning_of_life());

    return 0;
}

#endif

现在的main（）将被完全忽略，除非你用

Now main() will be entirely omitted unless you compile with

gcc -o scriptedmain -DSCRIPTEDMAIN scriptedmain.c scriptedmain.h

这code是安全的导入到其他C code，因为preprocessor将去掉的main（），更让您code本的主力。最好的部分是，这种解决方案不再依赖于晦涩的编译器的宏，只有简单的preprocessor说明。该解决方案适用于为好。

This code is safe to import into other C code, because the preprocessor will strip out main(), leaving you to code your own main. The best part is that this solution no longer depends on obscure compiler macros, only simple preprocessor instructions. This solution works for C++ as well.

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