Programming with no dependencies - c++

Question

I'm trying to make a PE (Portable Executable which will work with Windows XP+ and which has no dependencies.
I found this guide quite interesting http://www.catch22.net/tuts/reducing-executable-size
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
extern "C" int __cdecl __purecall(void)
{
return 0;
}
extern "C" int __cdecl main();
extern "C" int __cdecl mainCRTStartup( void )
{
int mainret;
mainret = main();
ExitProcess(mainret);
}
And I compile it with
g++ -Wall -o2 -s -nodefaultlibs main.cpp -o test.exe
And it's giving me a bunch of errors: http://i.stack.imgur.com/fIFoD.png
C:\Users\Main.cpp\Desktop\crt>g++ -Wall -o2 -s -nodefaultlibs -lkernel32 main.cpp -o test.exe
C:\Users\Main.cpp\AppData\Local\Temp\cczgOKUx.o:main.cpp:(.text+0x1c): multiple definition of `mainCRTStartup'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x280): first defined here
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x5): undefined reference to `__dyn_tls_init_callback'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x39): undefined reference to `__cpu_features_init'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x3e): undefined reference to `_fpreset'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x4b): undefined reference to `_CRT_glob'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x73): undefined reference to `__getmainargs'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x78): undefined reference to `_CRT_fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x82): undefined reference to `_imp___iob'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x87): undefined reference to `_fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x96): undefined reference to `_setmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x9b): undefined reference to `_CRT_fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xaa): undefined reference to `_setmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xaf): undefined reference to `_CRT_fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xbe): undefined reference to `_setmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xc3): undefined reference to `__p__fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xc9): undefined reference to `_fmode'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xd0): undefined reference to `_pei386_runtime_relocator'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xd8): undefined reference to `__main'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0xdd): undefined reference to `__p__environ'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x100): undefined reference to `_cexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x13f): undefined reference to `signal'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x195): undefined reference to `signal'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x1d0): undefined reference to `signal'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x217): undefined reference to `signal'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x233): undefined reference to `signal'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x250): more undefined references to `signal' follow
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x266): undefined reference to `_fpreset'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x28c): undefined reference to `_imp____set_app_type'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2ac): undefined reference to `_imp____set_app_type'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2c1): undefined reference to `_imp__atexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o:crt1.c:(.text+0x2d1): undefined reference to `_imp___onexit'
C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../../mingw32/bin/ld.exe: C:/TDM-GCC-32/bin/../lib/gcc/mingw32/5.1.0/../../../crt2.o: bad reloc address 0x20 in section `.eh_frame'
collect2.exe: error: ld returned 1 exit status
As far as I understood, my mainCRTStartup is interfering with another mainCRTStartup which my compiler is adding.
I'm using TDM-GCC on Windows.
After the suggestion to use -nostdlib instead of -nodefaultlibs I'm getting much less errors.
The ones I currently have are
C:\Users\Main.cpp\AppData\Local\Temp\ccMYa3VN.o:main.cpp:(.text+0x11): undefined reference to `__main'
C:\Users\Main.cpp\AppData\Local\Temp\ccMYa3VN.o:main.cpp:(.text+0x31): undefined reference to `ExitProcess#4'

Answer 1

GCC use some internal subroutines, contained in libgcc.a, that cannot be excluded.
See https://gcc.gnu.org/onlinedocs/gcc-5.3.0/gcc/Link-Options.html#Link-Options:
One of the standard libraries bypassed by -nostdlib and -nodefaultlibs
is libgcc.a, a library of internal subroutines which GCC uses to
overcome shortcomings of particular machines, or special needs for
some languages. (See Interfacing to GCC Output, for more discussion of
libgcc.a.) In most cases, you need libgcc.a even when you want to
avoid other standard libraries. In other words, when you specify
-nostdlib or -nodefaultlibs you should usually specify -lgcc as well. This ensures that you have no unresolved references to internal GCC
library subroutines.
P.S. The functions ExitProcess and SetUnhandledExceptionFilter are from kernel32.lib that you must include in linker stream. You can reduce libraries, but can't omit system and OS libraries.