C++ Windows Compiler for smallest executables

Question

guys I want to start programing with C++. I have written some programs in vb6, vb.net and now I want to gain knowledge in C++, what I want is a compiler that can compile my code to the smallest windows application. For example there is a Basic language compiler called PureBasic that can make Hello world standalone app's size 5 kb, and simple socket program which i compiled was only 12kb (without any DLL-s and Runtime files). I know it is amazing, so I want something like this for C++.

If I am wrong and there is not such kind of windows compiler can someone give me a website or book that can teach me how to reduce C++ executable size, or how to use Windows API calls?

Answer 1

Microsoft Visual C++ compiler for example... You just have to turn off linking to the C runtime ( /NODEFAULTLIB ) and your executable will be as small as 5KB. There's just one problem: you won't be able to use almost anything from the standard C and C++ library, nor standard features of C++ like exception handling, new and delete operators, floating point arithmetics, and more. You'll need to use only the pure OS features (eg create files with CreateFile , allocate memory with HeapAlloc , etc...).

Answer 2

I had to do this many years ago with VC6. It was necessary because the executable was going to be transmitted over the wire to a target computer, where it would run. Since it was likely to be sent over a modem connection, it needed to be as small as possible. To shrink the executable, I relied on two techniques:

1. Do not use the C or C++ runtime. Tell the compiler not to link them in. Implement all necessary functionality using a subset of the Windows API that was guaranteed to be available on all versions of Windows at the time (98, Me, NT, 2000).
2. Tell the linker to combine all code and data segments into one. I don't remember the switches for this and I don't know if it's still possible, especially with 64-bit executables.

The final executable size: ~2K

Answer 3

Reduction of the executable size for the code below from 24k to 1.6k bytes in Visual C++

int main (char argv[]) {
  return 0;
}

1. Linker Switches (although the safe alignment is recommended to be 512):

/FILEALIGN:16 /ALIGN:16

2. Link with (in the VC++ project properties): LIBCTINY.LIB

3. Additional pragmas (this will address Feruccio's suggestion)

However, I still see a section of ASCII(0) making a third of the executable, and the "Rich" Windows signature. (I'm reading the latter is not really needed for program execution).

#ifdef NDEBUG
#pragma optimize("gsy",on)
#pragma comment(linker,"/merge:.rdata=.data")
#pragma comment(linker,"/merge:.text=.data")
#pragma comment(linker,"/merge:.reloc=.data")
#pragma comment(linker,"/OPT:NOWIN98")
#endif // NDEBUG
int main (char argv[]) {
  return 0;
}

Answer 4

I don't know why you are interested in this kind of optimization before learning the language, but anyways...

It doesn't make much difference of what compiler you use, but on how you use it. Chose a compiler like the Visual Studio C++'s or MinGW for example, and read its documentation. You will find information of how to optimize the compilation for size or performance (usually when you optimize for size, you lose performance, and vice-versa).

In Visual Studio, for example, you can minimize the size of the executable by passing the /O1 parameter to the compiler (or Project Properties/ C-C++ /Optimization).

Also don't forget to compile in "release" mode, or your executable may be full of debugging symbols, which will increase the size of your executable.

Answer 5

A modern desktop PC running Windows has at least 1Gb RAM and a huge hard drive, worrying about the size of a trivial program that is not representative of any real application is pointless.

Much of the size of a "Hello world" program in any language is fixed overhead to do with establishing an execution environment and loading and starting the code. For any non-trivial application you should be more concerned with the rate the code size increases as more functionality is added. And in that sense it is likley that C++ code in any compiler is pretty efficient. That is to say your PureBasic program that does little or nothing may be smaller than an equivalent C++ program, but that is not necessarily the case by the time you have built useful functionality into the code.

@user: C++ does produce small object code, however if the code for printf() (or cout<<) is statically linked, the resulting executable may be rather larger because printf() has a lot of functionality that is not used in a "hello world" program so is redundant. Try using puts() for example and you may find the code is smaller.

Moreover are you sure that you are comparing apples with apples? Some execution environments rely on a dynamically linked runtime library or virtual machine that is providing functionality that might be statically linked in a C++ program.

Answer 6

I don't like to reply to a dead post, but since none of the responses mentions this (except Mat response)...

Repeat after me: C++ != ( vb6 || vb.net || basic ). And I'm not only mentioning syntax, C++ coding style is typically different than the one in VB, as C++ programmers try to make things usually better designed than vb programmers...

PS: No, there is no place for copy-paste in C++ world. Sorry, had to say this...