<sect1 id="gcc"><title>Using GCC with Cygwin</title> <sect2 id="gcc-cons"><title>Console Mode Applications</title> <para>Use gcc to compile, just like under UNIX. Refer to the GCC User's Guide for information on standard usage and options. Here's a simple example:</para> <example> <title>Building Hello World with GCC</title> <screen> <prompt>C:\cygnus\></prompt> <userinput>gcc hello.c -o hello.exe</userinput> <prompt>C:\cygnus\></prompt> <userinput>hello.exe</userinput> Hello, World <prompt>C:\cygnus\></prompt> </screen> </example> </sect2> <sect2 id="gcc-gui"><title>GUI Mode Applications</title> <para>Cygwin allows you to build programs with full access to the standard Windows 32-bit API, including the GUI functions as defined in any Microsoft or off-the-shelf publication. However, the process of building those applications is slightly different, as you'll be using the GNU tools instead of the Microsoft tools.</para> <para>For the most part, your sources won't need to change at all. However, you should remove all __export attributes from functions and replace them like this:</para> <screen> int foo (int) __attribute__ ((__dllexport__)); int foo (int i) </screen> <para>For most cases, you can just remove the __export and leave it at that. For convenience sake, you might want to include the following code snippet when compiling GUI programs. If you don't, you will want to add "-e _mainCRTStartup" to your link line in your Makefile.</para> <screen> #ifdef __CYGWIN__ WinMainCRTStartup() { mainCRTStartup(); } #endif </screen> <para>The Makefile is similar to any other UNIX-like Makefile, and like any other Cygwin makefile. The only difference is that you use <command>gcc -mwindows</command> to link your program into a GUI application instead of a command-line application. Here's an example:</para> <screen> myapp.exe : myapp.o myapp.res gcc -mwindows myapp.o myapp.res -o $@ myapp.res : myapp.rc resource.h windres $< -O coff -o $@ </screen> <para>Note the use of <filename>windres</filename> to compile the Windows resources into a COFF-format <filename>.res</filename> file. That will include all the bitmaps, icons, and other resources you need, into one handy object file. Normally, if you omitted the "-O coff" it would create a Windows <filename>.res</filename> format file, but we can only link COFF objects. So, we tell <filename>windres</filename> to produce a COFF object, but for compatibility with the many examples that assume your linker can handle Windows resource files directly, we maintain the <filename>.res</filename> naming convention. For more information on <filename>windres</filename>, consult the Binutils manual. </para> </sect2> </sect1>