Problem with Boost::Asio for C++ - boost

For my bachelors thesis, I am implementing a distributed version of an algorithm for factoring large integers (finding the prime factorisation). This has applications in e.g. security of the RSA cryptosystem.
My vision is, that clients (linux or windows) will download an application and compute some numbers (these are independant, thus suited for parallelization). The numbers (not found very often), will be sent to a master server, to collect these numbers. Once enough numbers have been collected by the master server, it will do the rest of the computation, which cannot be easily parallelized.
Anyhow, to the technicalities. I was thinking to use Boost::Asio to do a socket client/server implementation, for the clients communication with the master server. Since I want to compile for both linux and windows, I thought windows would be as good a place to start as any. So I downloaded the Boost library and compiled it, as it said on the Boost Getting Started page:
bootstrap
.\bjam
It all compiled just fine. Then I try to compile one of the tutorial examples, client.cpp, from Asio, found (here.. edit: cant post link because of restrictions). I am using the Visual C++ compiler from Microsoft Visual Studio 2008, like this:
cl /EHsc /I D:\Downloads\boost_1_42_0 client.cpp
But I get this error:
/out:client.exe
client.obj
LINK : fatal error LNK1104: cannot open file 'libboost_system-vc90-mt-s-1_42.lib'
Anyone have any idea what could be wrong, or how I could move forward? I have been trying pretty much all week, to get a simple client/server socket program for c++ working, but with no luck. Serious frustration kicking in.
Thank you in advance.

The reason the build is failing is because it cannot find the library file containing boost system. Boost includes a "handy" autolinking feature, such that when you include a header file for a binary libaray (as opposed to a header only library), boost automatically tells the compiler that it should link in the library. The downside to this is that boost doesn't tell the compiler where to find the library.
The short answer is to read a little further in the boost getting started guide. This page shows you how to add the necessary flags to the compiler command line: Getting started on windows: linking from the command line.
The first thing you have to do is find the .lib file. Boost hides them in a deep directory structure, so search for it starting in the directory you ran bjam from. Make note of the directory where the file is. You may also wish to use bootstrap --prefix=/some/install/location and bjam install to install boost somewhere other than the source directory in which you built it.
Are you building your project using a Visual Studio solution, or on the command line?
If you are using a solution file, find the link page in the solution properties. There should be a box where you can enter additional library paths. Add the directory in which you boost .lib files reside to this box.
If you are using cl on the command link, familiarize yourself with the command line options for cl and link. You can pass commands to the linker using the cl option /link, and the linker command you are looking for is /libpath.

Related

Cannot build EmulationStation (VS2015) from CMake solution file

I'm having difficulties trying to compile an opensource framework (EmulationStation) in VS2015 on Windows. I've never used any of the tools before, apart from Visual Studio - so please forgive me if these are some obvious mistakes.
The guide says i need to do like this:
Boost (you'll need to compile yourself or get the pre-compiled binaries)
Eigen3 (header-only library)
FreeImage
FreeType2 (you'll need to compile)
SDL2
cURL (you'll need to compile or get the pre-compiled DLL version)
(Remember to copy necessary .DLLs into the same folder as the executable: probably FreeImage.dll, freetype6.dll, SDL2.dll, libcurl.dll, and zlib1.dll. Exact list depends on if you built your libraries in "static" mode or not.)
CMake (this is used for generating the Visual Studio project)
(If you don't know how to use CMake, here are some hints: run cmake-gui and point it at your EmulationStation folder. Point the "build" directory somewhere - I use EmulationStation/build. Click configure, choose "Visual Studio [year] Project", fill in red fields as they appear and keep clicking Configure (you may need to check "Advanced"), then click Generate.)
This is how my CMake looks like (it says generating done)
I get alot of compilation errors in visual studio when trying to build though:
1) Cannot open include file: 'curl/curl.h': No such file or directory (compiling source file C:\Users\retropie\Documents\GitHub\EmulationStation\es-app\src\guis\GuiMetaDataEd.cpp) emulationstation C:\Users\retropie\Documents\GitHub\EmulationStation\es-core\src\HttpReq.h
Where do I get this header file from?
2) 'round': redefinition; different exception specifications (compiling source file C:\Users\retropie\Documents\GitHub\EmulationStation\es-app\src\guis\GuiMenu.cpp) emulationstation C:\Users\retropie\Documents\GitHub\EmulationStation\es-core\src\Util.h 18
I have a lot of these errors with round. Am I missing a reference to a library?
Another screendump of some of the errors from VS2015:
Hope someone can point me in the right direction.
I am currently in de same boat as you, trying to get ES building under MSVS2015.
I am also very green, so hopefully others chime in as well.
Regarding the 'round' errors, apparently the MS compiler has no knowledge of these. For this issue, and some others, the newer ES fork by Herdinger has fixed this.
As this is currently the most active ES branch out there, and has the explicit goal of consolidating at least some of the backlog of PRs from the original Aloshi git, I would suggest you use this one.
In issue #4, there is some more information on building in recent VS versions. There is also a link for the precompiled cURL libs, including the header.
Having gone that far, I am sad to say that I still do not have a succesfull build as of yet. Compiling is no problem, however linking gives me a LNK2005 error.
Hope this helps a bit. Let me know how you fare.

mingw32 posix threading library

I have installed MinGW on my windows7 machine, using instructions from here. Basically I used the GUI installer assistant called mingw-get-setup.exe. The installation manager allowed me to select a package called mingw32-libpthreadgc which installs bin/pthreadGC2.dll and bin/pthreadGCE2.dll.
To my knowledge that is not sufficient to compile code depending on the pthread library. E.g. trying to compile a file with a header-include like #include "pthread.h" - to no surprise - results in a "file not found" compile error. I can't find that header in my MinGW directory. If I use includes/headers from elsewhere, I'm afraid they might not match with the DLL's interface. How is this meant to be working?
(Furthermore I like to use CodeBlocks as the IDE. How would I set up a simple "HelloWorld"-like pthread program to get it all to work? There seems to be a lot of conflicting messages out there on how to set it up. Use "-pthread" vs "-lpthread". Set it in compiler and linker settings, right? Copy-paste the DLL's? What else???)
I had similar problem, https://www.sourceware.org/pthreads-win32/ this did job for me,
I used this in combination with mingw32. It also has nice README file.

Error Linking Boost Libraries With Quantlib

I am trying to build Quantlib using Boost Libraries.
I followed the instructions here: and also on the Quantlib website.
I downloaded and unzipped boost_1_57_0 into C:\program files
I then used the Visual Studio 2013 x64 Native prompt to go to the boost directory and ran
bootstrap.bat
and then
b2 --toolset=msvc --build-type=complete architecture=x86 address-model=64 stage
Then I opened Quantlib_vc12.sln in Visual Studio 2013.
Picked "Release" and "x64", opened "Quantlib" in Property Manager and set the VC++ Directories.
In the include directories I added C:\Programm Files\boost_1_57_0
In the Library Directories I added C:\Program Files\boost_1_57_0\stage\lib
Then I went to the Solution Explorer and right clicked and chose build.
I got one LNK1104 error.
LNK1104: cannot open file 'libboost_unit_test_framework-vc120-mt-1_57.lib
Please see attached screenshot:
I have no idea how to fix this and I would really appreciate some help. I had successfully installed this at work using an admin account but was not able to access Quantlib using my user account. I have since deleted and attempted installations atleast 15 times but it's not working. I am worried that all these attempts at installing may have messed something else up, like some registry (I have no idea how that works but I only know to be afraid). Please help! Thanks.
UPDATE: Still get the same error after adding BOOST_AUTO_LINK_NOMANGLE define to project.
UPDATE2: I am getting these messages on the screen while running b2 to build boost. Is this an error I need to fix?
This is exactly what I warned you about in another related question/answer. What's happening here is that the boost headers you are including in this quantlib are (through macros) detecting that you're using MSVC, detecting the version, then automatically linking the required DLL files to build quantlib using #pragma comment(lib....). So even though under Project Settings -> C/C++ -> Linker there are no external DLL's or Lib's specified, they're still being linked by these pragma statements.
So when these macros are detecting your compiler and so on, they're dynamically building a string name of what they think the required libraries would be named on your system. Remember when you built boost, you specified the -layout option. This the naming layout of your boost libraries. Well by default, that layout is something like this:
LIB_LIBRARY_NAME_COMPILER_VERSION_SingleOrMultiThreaded_BOOST_VERSION.LIB
Which in practice looks like this:
libboost_unit_test_framework-vc120-mt-1_57.lib
This is boost "mangling" the name of your library to be as descriptive as possible about how the libraries were build so that, just by glancing at the file name, you know. What we do with -layout=system is tell the boost build system NOT to mangle the names, but to name them according to what option we gave to "layout". Since we chose layout=system, boost is going to name our libraries like this:
LIB_LIBRARY_NAME.LIB
Which in practice will produce:
libboost_unit_test_framework.lib
So when we start using boost after doing this (with MSVC only does this happen), these dynamically generated linker statements don't give a rip about or know about what -layout option you built boost with. They will attempt to link in required libraries using the fully mangled naming format, which is why you get the error:
cannot open file 'libboost_unit_test_framework-vc120-mt-1_57.lib
.. because you don't have a file named that! That's the mangled name! You have a file named libboost_unit_test_framework.lib. See the difference! So, you need to tell these stupid macros to stop mangling the library names when auto-linking required libraries. You do that by adding the following preprocessor definition to your Quantlib project:
BOOST_AUTO_LINK_NOMANGLE
You add that in Project Settings -> C/C++ -> Preprocessor -> Preprocessor definitions.
If you'd rather avoid this headache and don't care about the long and (imo ugly) mangling that boost does to library names, you can build boost omitting the -layout option and it will default to this mangled naming convention, where you shouldn't get stuck on this error at all anymore. I personally put out the effort to keep nice short/clean library names but it's all about preference.
Edit
Since you have the same error after fixing the NO_MANGLE problem, then the only possible reason that you're getting this particular link error is that you do not have whatever file the linker is complaining about missing stored in any of the directories supplied to the linker.
Verify the folders/paths you provide to the linker and verify that the file the linker is looking for is in one of the directories that you're providing to the linker. You have to provide directories to the linker because you're telling the linker "you can look in all of these places for the libraries my project needs". If you specify none, it's got nowhere to look. :(
Example:

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.

Using a .lib built with Visual Studio in Eclipse/CDT/gcc

I am having some trouble compiling a programm with gcc on windows which was initially developed with Visual Studio. So far I was able to resolve almost all problems like missing header files and such, but now I am stuck at one last thing: gcc fails to link to one of the third party libs my program uses (FlyCapture2.lib). It tells me that it does not find any of the functions/methods there. I already checked if the library is actually on the library path and that sort of things, but it still does not work.
I searched a bit around and learned that it might have something to do with the format of .libs created with the Microsoft compiler. Is there any way to convert such a lib to be compatible with gcc? Anything else I might have missed?
(I already found this similar question, but its solution won't work here)
In this page the author gives several ways to achieve what you want

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