Simple Win32 example with as and ld

[Gunther]

The archive mesbox.zip contains both, a C program and an assembly language program; the functionality is the same (displaying a messagebox and terminating). Both are generated with MinGW 4.6.2. The C source is compiled with: gcc -o hello.exe hello.c -mwindows. The result is a 50 KB EXE.

The assembly language source is in mesbox.s (Intel syntax); for building the program, please check out build_mesbox.bat. There's another, more sophisticated example by Vortex, which you can check here: http://masm32.com/board/index.php?topic=1140.msg10851#msg10851. Thank you, Erol.  :t

Gunther

[qWord]

Just for your information, LD breaks with Microsoft's PE/COFF specification by default: If you look into hello.exe you will find section names greater than 8, which is not allowed for PEs.
If one is interest in conform executables, he might use the well documented switch "-disable-long-section-names".

[Gunther]

Hi qWord,

Just for your information, LD breaks with Microsoft's PE/COFF specification by default: If you look into hello.exe you will find section names greater than 8, which is not allowed for PEs.
If one is interest in conform executables, he might use the well documented switch "-disable-long-section-names".

you're probably right, but I'm the false adressee. You should leave a comment for the compiler builders.

Gunther

[Magnum]

It's interesting how much bigger the C version is.  23X

Is MinGW an optimizing compiler ?

Andy

[Gunther]

Hi Andy,

It's interesting how much bigger the C version is.  23X

Is MinGW an optimizing compiler ?

Andy

I don't know, but MinGW is the port from the the Linux gcc for the Windows OS. It's a fairly good compiler. You should give it a try, if your system is repaired.

Gunther

[Gunther]

Hi qWord,

If one is interest in conform executables, he might use the well documented switch "-disable-long-section-names".

Fixed.

Gunther

[Greenhorn]

BTW, the reason why the C version is so huge is explained here.

[anta40]

BTW, the reason why the C version is so huge is explained here.

That page is about C++, and because C++ has more language features than C, it's not surprising that C++ executables can be larger than their C counterparts. A canonical hello world C++ program, compiled with older versions of MinGW g++, could yield a ± 500 KB exe.

[Magnum]

Greenhorn,

That is interesting info.

Even if it has the debug info, size isn't that bad.

I have seen some Visual Basic programs that were about 100x the size of an assembly program that does the same thing.

[Gunther]

Hi Andy,

I have seen some Visual Basic programs that were about 100x the size of an assembly program that does the same thing.

that is clear, because a HLL compiler produces a lot of red band, which isn't really necessary for executing.

At the moment, I'm experimenting with as and ld under Win7 (64 bit). It's a mess, because the linker can't find the necessary libraries. There is on the other hand such a tool like Bogdan's SoAsm; it's well written, lean and under active development. But I can't re-compile the provided Linux object code, because it's for 32 bit. Bad luck. May be that Bogdan can provide a native 64 bit object file. I've asked him via PM. SolAsm seems to be a great tool and is useable under Windows and Linux.

Gunther

[jcfuller]

Using this gcc(4.7.2) distro: http://nuwen.net/mingw.html
the exe is 8,704

Of course using Tiny c the size is the same as "as" -> 2048

James

[Gunther]

Hi James,

Using this gcc(4.7.2) distro: http://nuwen.net/mingw.html
the exe is 8,704

is that the 64 bit Windows version?

Gunther

[jcfuller]

No. 32bit only.

I primarily use the TDM version http://tdm-gcc.tdragon.net/

It is 32/64

James

[Vortex]

Hi Gunther,

Thanks for your example :t

[Vortex]

If you look into hello.exe you will find section names greater than 8

I am afraid this not true. Analyzing the executable with LordPE :

Code Select Expand

Section name     Length of section name

.text     5
.data     5
.rdata     6
.eh_fram     8
.bss     4
.idata     6
.CRT     4
.tls     4
.debug_a     8
.debug_p     8
.debug_p     8
.debug_i     8
.debug_a     8
.debug_l     8
.debug_f     8
.debug_s     8
.debug_l     8
.debug_r     8

Thanks for explaining the -disable-long-section-names option. :t