Creating smallest DLL file - windows

I have created a DLL file (library) with one assembler function. This file is 75kB size. How to make this file smaller? Like I suspect, there is an automatically included System unit. Can I exclude this unit from my dll file?

I googled your Issue, as it came to my mind in Visual C++ there are Debug&Release Modes.
So maybe you can try creating a smaller Dll using the Release Mode. I found some settings for this: http://bugs.freepascal.org/bug_view_advanced_page.php?bug_id=18632
Maybe this helps you, but I'm not sure it will work because I didn't work with Pascal for like 2 years :)

Why? are you concerned about binary sizes on one hand, and have a 64-bit tag on the other?
Debug info, pass -Xs to strip debuginfo
Smartlinking, pass -XX (dead code elimination) 1+2 combines to -XXs
Avoid advanced functionality. Do NOT set any $Mode, the delphi compatible additions to system will bulk it up.
If you want to further reduce you will have to edit the RTL source and recompile it.

You can also try UPX to pack your DLL-s. I recently made a simple DLL in Delphi and here are some observations I made:
1) Delphi 7 made almost 2 times smaller file than Delphi XE3 (32bit, Release mode). Lazarus made the biggest file. So maybe older FPC can make smaller file?
2) I stripped all non-mine units from the library. I even replaced Math and Windows with my own, super-short versions. This reduced the file size about twice.
3) System unit is something you can't just remove, but there are ways to create your own, recompile and replace. I guess this is also possible with Lazarus/FPC.

Related

Python/C API: Statically-Linked Extensions?

I've been writing a Python extension use the Python/C API to read data out of a .ROOT file and store it in a list of custom objects. The extension itself works just fine, however when I tried to use it on a different machine I ran into some problems.
The code depends upon several libraries written for the ROOT data manipulation program. The compiler is linking these libraries dynamically, which means I cannot use my extension on a machine that does not have ROOT installed.
Is there a set of flags that I can add to my compilation commands to make these libraries statically linked? Obviously this would make the file size much larger but that isn't much of an issue providing that the code runs at the same speed.
I did think about collating all of the ROOT libraries that I need into an 'archive' file. I'm not too familiar with this so I don't know if that's a good idea or not.
Any advice would be great, I've never really dealt with the static/dynamic library issue before.
Thanks, Sean.

How to Publish/Export wxWidgets Application

newbie here.
Want to ask for any advice on how to Publish/Export, CodeBlocks Application made by using wxWidgets. After some research, i discovered that i should use DLL, or something like that, but since I am really new into it, I am missing the logic on how I should actually implement that. Since CodeBlocks offers wxWidgets and DLL as separate projects. So I am not really sure how to properly combine. Thanks in advance.
If you used wxWidgets as .dll, to get a self-standing package you have to distribute all the requested libraries. The simplest way is just to copy them from their source folder (in your case [wxWidgets root]\lib\gcc_dll) in the same folder as your executable. There could be many of them, but usually only two or three are needed. For simplicity you can copy them all, or you can try repeatedly to start the program, and add each time the library indicated in the error message.
Please note that to distribute your application you will probably want to compile it in Release mode, and consequently you should ship the Release .dlls (i.e. beginning with wx...28_ instead of wx...28d_).

Compiling libexif as static lib with Visual Studio 2010 - then linking from Visual C++ project

Is it possible to compile libexif with Visual Studio 2010? I have been trying to do so and have been running into a whole slew of problems. I cannot find any information about whether anybody has successfully done this before. I know I can use MinGW to compile the library, but I am in a situation where I need it to be compiled with Visual Studio and then need to link to it from a Visual C++ app. Is this possible?
To answer your question: Yes it is possible... but it is a bit of a hack. Libexif uses functions that MSVC has chosen not to implement. See my working example VS2010 project below (if you don't like downloading files then skip to my explanation of what needed changing to get it to work below):
https://www.dropbox.com/s/l6wowl8pouux01a/libexif-0.6.21_CompiledInVS2010%2BExample.7z?dl=0
To elaborate, the issues that needed a "hack" (as hinted in the LibExif readme-win32.txt documentation) are:
Libexif uses inline in several places which is not defined in VS for C, only C++ (see this)
Libexif uses snprintf extensively in the code which is not defined in VS (see here)
You need to create the config.h yourself without a ./configure command to help you. You could read through the script but most of it doesn't make sense for Windows VS2010.
You will need to define GETTEXT_PACKAGE because it's probably setup in the configure file. I just choose UTF-8, whether that is correct or not I'm not sure.
There was a random unsigned static * that needed to be moved from a .c file to the .h file as C in VS doesn't allow you to create new variables inside functions in the particular way they were trying to do.
Read the "readme-win32.txt" file. Advice is:
hack yourself a build system somehow. This seems to be the Windows way of doing things.
Don't get your hopes up. The *nix way of doing things is the configuration script that needs to be run first. It auto-generates source files to marry the library to the specific flavor of *nix. The configuration script is almost half a megabyte. Three times as much code as in the actual .c files :) You cannot reasonably get that working without MinGW so you can execute the script. Once you got that done, you've got a better shot at it with a VS solution. As long as it doesn't use too much C99 specific syntax.

Multiple Boost.Thread Instances OK in a C++ application?

I have an application with a plug-in architecture that is using Boost.Threads as a DLL (specifically, a Mac OS X framework). I am trying to write a plug-in that uses Boost.Threads as well, and would like to link in the library statically. Everything builds fine but the application quickly crashes in my plug-in, deep within the Boost.Threads code. Linking to the DLL version of Boost.Threads seems to resolve the problem, but I'd like my plug-in to be self-contained.
Is it possible to have two instances of Boost.Threads with such a setup (one as a DLL, one statically linked in another DLL)? If so, what might I be missing to make the two instances get along?
Once my team faced a similar problem. For reasons I will not mention at this time, we had to develop a system that used 2 different versions of Boost (threads, system, filesystem).
The idea we came up with and executed was to grab the source code of both versions of Boost we needed, and then tweak one of them to change the symbols and function names to avoid name clashing.
In other words, we replaced all references to the name boost for bubbles inside the sources (or some other name) and also made changes to the compilation so it would build libbubbles instead of libboost.
This procedure gave us 2 sets of libraries, each with having their own binaries and header files.
If you looked at the source code of our application you would see something like:
#include <bubbles/thread.hpp>
#include <boost/thread.hpp>
bubbles::thread* thread_1;
boost::thread* thread_2;
I imagine some of the guys here already faced a similar situation. There are probably better alternatives to the one I suggested above.

Find Programming Language Used

Whats the easiest way to find out what programming language an application was written in?
I would like to know if its vb or c++ or delphi or .net etc from the program exe file.
Try PEiD
of course if they used a packer, some unpacking will need to be done first :)
Start it up and check what run-time DLLs it uses with Process Explorer.
If that doesn't make it immediately obvious, search the web for references to those DLLs.
Most disassemblers (including Olly I think) can easily show you the text contained in an EXE or DLL, and that can also sometimes give a clue. Delphi types are often prefixed with T as in TMyClass.
If it's a small executable with no DLL references and no text you might be SOL. At that point you'd need to look for idioms of particular compilers, and it would be mostly guesswork.
There is an art to detecting what language a program was written in. It is possible but there are no hard and fast rules. It takes a lot of experience (and it also leads to the question "Why would you want to..." but here are a few ideas on how to go about it.
What you're looking for is a "signature". The signature could be a certain string that is included by the compiler, a reference to an API that is quite common in the programming tool being used, or even a style of programing that is common to the tools being used, visible in the strings contained in the application.
In addition, there are styles to how an application is deployed: various configuration files found in the deployment directory, dlls and assemblies and even images, directories or icons.
Java applications wrapped in a self-launching executable will contain references to java libs, and will likely have certain libraries or files included in the same directory that indicate that it's java.
As indicated in other answers a managed assembly will show certain signs as well: you can open it in Reflector etc. While it is correct that c# and VB are "interchangable" once compiled, it is not true that they are identical. If you use Reflector to disassemble VB code you will quite often see that the assembly references the Microsoft.VisualBasic.dll assembly. You'll be able to tell the difference between Mono applications because they will most likely contain references to the mono assemblies.
Many compilers assemble and link code in certain ways, and leave footprints behind. For example, examining a window executable using "strings: tab in Process Explorer, you'll see a lot of strings. Using these you may be able to determine programming styles, methods called, error or trace methods withint the exe.
An example is that compilers use different mechanisms for localization: Microsoft stores localized strings in XML files or resource files. Other compilers will use a different tactic.
Another example is c++ name mangling. The CodeWarrior compiler uses a different algorithm to mangle the names of the member variables and functions of a call than Visual Studio.
I suppose you could write a book on the subject of accurately determining the lineage of any executable. This subject would probably be called "programming archeology".
You could try using Depends to see what runtime dependancies it has, which might give some clues.
The easiest way is to ask the developer of the program. It does not require any knowledge and utility programs.
Determine Delphi Application
Use eda_preview270.exe (from here) or some other spy tool and check the window class names. If they read like TButton or TfrmBlubb, it's a VCL app. If there is an "Afx" in them, it's probably MFC.
Compiled languages (by this I mean no scripting languages, or Java, .NET, etc.) are compiled into CPU assembly instructions, which is essentially a one-way conversion. It is not usually possible to determine which language a program was written in. However, using a dependency walker, you could potentially determine which runtime library the program was loading (if any) and therefore determine which language it used (e.g. MS Visual C++ 9 uses msvcr90.dll).
you can check is that a .net assembly or not by trying to open with ildasm.exe tool
PE Detective works best for me.
In general, you can't.
If you can load it into Reflector, you know it is a managed assembly.
That's a good question. There isn't any general way to tell, but I bet most compilers and libraries leave a mark in the resulting EXE file. If you wanted to spend a lot of time on it, you could gather a bunch of EXEs written in known languages and scan for common strings. I would image you'd find some.
Dependancy Walker, which someone else mentioned would be a good way to look for telltale dependencies, like versions of MSVCRT, etc
i'd try running the .exe thru a 'strings' program to get assorted hints.
If I remember correctly PE Explorer Disassembler gives some information about compiler that creates given not .net and java binary, for .net use Reflector or ILDAsm tool
The easiest way that I found (at least in computer games) was to look in the "redist" folder nested within the game's main folder. It might be obvious to some of you that are more experienced in programming yourself, but the specific purpose of the MSI in this folder is to allow the setup.exe file to automatically install the prerequisites for the game itself.
For example:
In Empire Total War, there is an MSI called "vcredist_x86-sp1.exe". This indicates that the game/program was written in Microsoft's "Visual C 2005" in the .NET Framework (usually).
In fact, if you open the MSI/EXE, the installer should immediately indicate the language it's written in and which version.
The reason I'm familiar is because I code in C# and VB in the .NET Framework and we auto-install the prerequisites for our business app.
Hope this helps!

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