Dark Bit Factory & Gravity

PROGRAMMING => C / C++ /C# => Topic started by: xteraco on July 05, 2006

Title: Making and using dll's in c++ (code::blocks) gcc
Post by: xteraco on July 05, 2006

ok, heres a good tutorial that i think belongs in the c++ section here... basically its a extremely simple program that shows how to make a dll, and then make an exe that can read from it... pretty simple :) 

-enjoy

Title: Re: Making and using dll's in c++ (code::blocks) gcc
Post by: Shockwave on July 05, 2006

Cheers dude :) + Karma!

Title: Re: Making and using dll's in c++ (code::blocks) gcc
Post by: Paul on January 05, 2007

I've tryed to learn c++ before but gave up since I diddn't know anyone hwo knew the language and now i tryed this...

I get the error when tyying to compile it
[Linker error] undefined reference to `WinMain@16'

Edit:
I tryed some other code and got the same error

Edit:
This may help

Compiler: Default compiler
Executing  g++.exe...
g++.exe "C:\Documents and Settings\david1.DAVID\Desktop\paul\blitz userlib tests\dono\c++\tutirial\dll\dll.cpp" -o "C:\Documents and Settings\david1.DAVID\Desktop\paul\blitz userlib tests\dono\c++\tutirial\dll\dll.exe"    -I"C:\Dev-Cpp\lib\gcc\mingw32\3.4.2\include"  -I"C:\Dev-Cpp\include\c++\3.4.2\backward"  -I"C:\Dev-Cpp\include\c++\3.4.2\mingw32"  -I"C:\Dev-Cpp\include\c++\3.4.2"  -I"C:\Dev-Cpp\include"   -L"C:\Dev-Cpp\lib"
C:\Dev-Cpp\lib/libmingw32.a(main.o)(.text+0x106):main.c: undefined reference to `WinMain@16'
collect2: ld returned 1 exit status

Execution terminated

Title: Re: Making and using dll's in c++ (code::blocks) gcc
Post by: Jim on January 05, 2007

Depends what kind of program you're trying to write.  If you're writing a normal command prompt program, the execution of your code begins with a function called main().  If you're writing a Windows program then your code begins with WinMain().  And if you're writing a DLL, your code gets called at DllMain().
So, C and C++ command line programs look like this

Code: [Select]

int main(void)
{
  //your code goes here
  return 0;
}
and a Windows app looks like this

Code: [Select]

#include <windows.h>
int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
  //your code goes here
  return 0;
}

I think the problem is you've got your dev C settings wrong, and you're trying to build a command line program as a Windows program, and it thinks that WinMain() is missing.

Jim