What's the best way to compile and include a static library (in this case OpenCV) for use in a R package distributed as a binary package. Should I compile it as static outside of R and then put relevant .a files in "inst" or should I include all the source and header files of OpenCV in "inst" and compile from R?
I understand that CRAN will never accept this but it's more for the purpose of making deployment easier for users so they do not need to compile OpenCV or the package from source themselves.
If I get some good pointers on how to proceed or a package that have done something similar I intend to write up a short blog post for other people who want to do the same thing but with other large external libraries (both on Linux, OSX and Windows).
I apologies before hand if I've failed to appreciate that this question has been asked several times before.
Related
I can't seem to find anything on the internet which show you how to build and compile a C++ library such that it can be used in R via the Rcpp package. I am missing some steps where the library is somehow linked to R tools
For instance how do you get the boost library working with R or any other such library?
Normal instructions:
https://andres.jaimes.net/718/how-to-install-the-c-boost-libraries-on-windows/
https://www.boost.org/doc/libs/1_55_0/more/getting_started/windows.html#or-build-from-the-command-prompt
This is almost surely a duplicate but I am in-between tasks and cannot search now...
"It's still complicated" but Rcpp 1.0.5 now also ship this arXiv paper I wrote on this as this vignette. In short, you need to differentiate between
header-only you can ship or include
small-ish library you include and build
an external library
The third one is hardest as you now have the problem of getting it to CRAN and your users.
First I'll explain the big picture :
I am creating an application where I separated most of the features in different libraries. One of them contains some classes that use curl. I actually use Ubuntu 64 bit to develop and test it, but my production environment is a NAS with an ARM processor. I intend to, later, also make it for windows.
Where I am now :
My application is running on linux and the ARM-based NAS. However, I don't link with curl, I use curl from command-line internally to do what I need. This has some drawbacks :
As a programmer, I consider it an ugly practice. I should link to libcurl, this is the normal and clean way of using features from other software components.
This implies that curl executable is installed on the target. Not only I don't want to rely on this but also after a system upgrade on the NAS, I found out that I can't rely anymore on this.
What I want
As I intended anyway to use curl as a library, I first tried to do it the "soft way" : dynamic linking. Although it worked on my development environment, it didn't work on the production one because I found out that the curl library installed there doesn't work as expected.
So my next try was using libcurl as a static library. I also considered it to be the best future-proof option for me as it would make sure that, either on the NAS or on any other system, the library I will be using will always be the same.
The problems I've solved so far
Including a static library in another static library
This is already well documented in other answers here in StackOverflow : How to merge two "ar" static libraries into one
I did this to create a combined library of my own one and libcurl and as far as I've checked, it worked.
Building libcurl statically from source
There also are other answers that cover this topic, and I managed to create a libcurl.a that has libcurl features only.
The problems I am still trying to solve
Building libcurl statically with all its dependencies
There are some information regarding this, for example here. I did what was suggested, calling the configure script with --disable-shared and --enable-static. I also did the "rm src/curl" before make and called make with LDFLAGS=-all-static, but the resulting libcurl still missed its dependencies (openssl, pthreads, zlib...).
If I could solve this problem, it would answer my question. But not having succesfully done that, I tried another approach :
Manually merging all libcurl dependencies in a final lib
As I did for merging my library with libcurl into a new library, I also tried do add to it curl dependencies : zlib and openssl. So I compiled both from source to create static libraries and included them in the merge. I was not able to fully check the result as it seems that another one is missing : pthread. And I was not able to find pthread for downloading - compiling - static linking.
Looking at the big picture, my main problem is : how to I include curl in my final application so that there is no external dependency to it?
I think that if either of my two remaining problems would be solved, I would be solving my main problem. But if it is not the case, I also would be glad to hear from someone who knows a better way of solving this, or ideally already solved a similar issue.
Sorry if this all seems too simple but I'm a beginner and I'm trying to use the OpenBlas libraries in my C++ IDE "CodeBlocks" on Windows. More specifically, I'm want to use the matrix-vector multiplication and solving of a tri-diagonal matrix system libraries. I've downloaded the files at the bottom of the page on the OpenBlas site. I'm not sure how I would even start, as there are little/no resources online for beginners such as myself. What libraries do I need to include in my .cpp file preamble, have I even downloaded the correct set of files, which files do I need to include in my working directory, etc?
Thanks in advance.
EDIT: I've downloaded the pre-built files as recommended and followed every step in the link below.
http://www.learncpp.com/cpp-tutorial/a3-using-libraries-with-codeblocks/
I have also included #include "cblas.h" in the preamble of my .cpp file but I am getting a undefined reference to 'cblas_XXXXX' error in my build messages. What is the reason for this?
Download the pre-built winodws library
https://sourceforge.net/projects/openblas/files/v0.2.15/OpenBLAS-v0.2.15-Win64-int32.zip/download
I am currently trying to setup a project in C++, b that uses the luabind library. Unfortunately on my distro, namely Arch, this library isn't in the official repos and the one in the AUR is out of date and fails to compile.
Considering that I need the library only for this project I thought that I could make a sandboxed environment similar to python's virtualenv by building the library then installing(copying) the include files and resulting binaries in 2 sub-directories of my project called include and lib, respectively which I'll add to the linking and include paths when building. I understand why distributing the libraries with your project is bad: security and bug fixes in the meantime for example. However distributing DLLs is almost universally done on Windows(which I might do if I cross-compile) and many projects such as games on Linux tend to package their libraries to avoid inconsistencies between disrtos. Moreover if ever need a patched or forked version of a lib I doubt I'll ever find it in any official repo.
So my question is:
Is what I described above a common practice? Should I do it like this?
If not, what is the most commonly-agreed-upon solution to this problem?
NOTE: I use Cmake for build automation, if it matters
EDIT: This question slightly overlaps with mine.
Your approach is interesting, but it is not necessary for you to devise a working system because it has already been done, and luckily, you are only one step away from the solution !
Using CMake, it is easy to automate the building and linking of external source code, using the ExternalProject module.
See http://www.kitware.com/media/html/BuildingExternalProjectsWithCMake2.8.html for useful information.
This approach has several advantages:
you do not have to include the library's source code in your repository
you can point to the specific version/git tag of the library that you know works with your software OR the latest release if you are certain it will not break compatibility
you do not have to write a complete CMakeLists.txt file to build a possibly complex code base
you can eventually configure the external project to build as a static library so you will not have to distribute shared libraries
you can even completely bypass this if not necessary, by trying to detect a working version of the library on your system with the usual find_package call, and only fall back to building it as an external project if not found
I'm working on a project written in C++ that uses the Boost Regex library to do some parsing. My problem is, I need to run the program on a remote machine that doesn't have the boost library installed. I also don't have admin access to this computer so I can't just install it myself.
Is there any way to separate out just the Boost Regex library so that I can put it in the same directory as my other code? I tried doing this already by downloading the boost library and separating out all of the unneeded headers and such. I managed to get it to a point where it calmost compiled but it failed at the linking stage.
Is there anything I can do to fix this or will I be forced to rewrite the parsing code?
You can use the Boost.BCP tool to extract a subset of Boost.
include the static library libboost_regex-gcc-1_35.a your list of object files to compile.
1_35 is an older version number on my linux box, you may have a newer library