undefined reference to 'WinMain@16'

现象

一个C的项目，以64位模式编译时没有问题，切换到32位编译就报告错误：

undefined reference to ['WinMain@16'](mailto:'WinMain@16')

原因

首先上原来的代码：

#include <windows.h>

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
ShellExecute(NULL,"open","taskkill"," /F /IM nginx.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM php-cgi.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM php.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM BeyondClass.exe",NULL,SW_HIDE);
return 0;
}

根据错误提示和网上找到的资料，说是因为这段代码没有main()函数导致。

解决

在代码中增加一个main函数：

#include <windows.h>

int main()
{
ShellExecute(NULL,"open","taskkill"," /F /IM nginx.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM php-cgi.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM php.exe",NULL,SW_HIDE);
ShellExecute(NULL,"open","taskkill"," /F /IM BeyondClass.exe",NULL,SW_HIDE);
return 0;
}
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
main();
return 0;
}

再编译，OK，问题解决了。