Undefined reference to WinMain (C++ Mingw)
currently I am trying to make a windows application using c++. For compiling my program I use Mingw GCC. Btw I'm on Windows 10.
But as soon as I use int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE, PWSTR pCmdLine, int nCmdShow) instead of int main() the compiler shows me following message:
C:/mingw-w64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.1.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-crt0_c.o):crt0_c.c:(.text.startup+0x2e): undefined reference to `WinMain' collect2.exe: error: ld returned 1 exit status The terminal process terminated with exit code: 1
The example code I tried to compile I got from this Windows application tutorial: Example Code
I have already tried reinstalling mingw but it did not help. That's why i hoped someone here could help me with my problem. Thank you in advance!
Answer
This example code uses wWinMain but
One thing to note is that Visual C++ supports a “wWinMain” entry point where the “lpCmdLine” parameter is a “LPWSTR”. You would typically use the “_tWinMain” preprocessor definition for your entry point and declare “LPTSTR lpCmdLine” so that you can easily support both ANSI and Unicode builds. However, the MinGW CRT startup library does not support wWinMain, so you’ll have to stick with the standard “WinMain” and use “GetCommandLine()” if you need to access command line arguments.
via Building Win32 GUI Applications with MinGW
In this specific case, you can use WinMain instead. This program doesn't use pCmdLine value, so it should compile when you change wWinMain to WinMain and PWSTR pCmdLine to PSTR pCmdLine.
If you later would need unicode command line use LPWSTR cmd_line = GetCommandLineW(); instead of WinMain argument.
Newer Mingw versions also support -municode linker option switching to alternate startup code allowing to use wWinMain instead of WinMain (or wmain instead of main). Add it to your command line, linker options in IDE or makefile.
g++ other_options_and_arguments -municode