when i try to execute the Linux executable on other fresh machine my program gives an error for dependency of OpenSSL.
For running my program smoothly it requires libssl.so and libcrypto.so preloaded.
How can i remove this dependency using make file or any other solution on Linux
It seems that you linked your executable with OpenSSL libraries dynamically. So your executable needs libcrypto.so and libssl.so. You have two ways:
OpenSSL is pretty widely distributed in Linux environment and most probably is pre-installed on the Linux you are running your executable on. So the problem may be in the required version of the libraries - your executable may be compiled with e.g. OpenSSL 1.0.1 and Linus has 0.9.8. Or the problem could be with the path of the libraries. In RadHat OpenSSL libraries are in /lib64 by default. So you need either to build your application with the same or compatible version of OpenSSL as present on Linux where you run or provide the correct path by setting LD_LIBRARY_PATH
You can link your executable static with OpenSSL libraries:
gcc -lsome_dynamic_lib code.c libcrypto.a libssl.a
Related
I have a C++ project that I'm currently building using dynamic linking to various system libraries. It's on a RHEL 7 system. I've been using devtoolset-9 to get a more modern version of g++ (the system one is 4.8.5, I think). It all works fine, but I'd like to now build a static executable that I will be able to run on a non-RHEL linux system. I've tried specifying -static-libstdc++, but it appears to still be dynamically linked, looking at the ldd output. I've read that devtoolset compilers use some link-time trickery to link in both the system libstdc++ dynamically and any new C++ functionality statically. Is this true? It doesn't work for me; if I copy the executable over to the non-RHEL system and try to run it, I get a bunch of things like this (from memory, so hopefully correct):
/lib64/libstdc++.so.6: version `GLIBCXX_3.4.21' not found
Is there any way to build a fully static executable using g++ from devtoolset-9? Thank you.
I have a c++11 library ( https://github.com/matiu2/cdnalizer ). I want to distribute it on centos6 and ubuntu12.04 LTS.
It compiles happily on Ubuntu 13.10 and Gentoo.
I tried compiling with as much staticness as I could, but it still depends on a glibc that centos doesn't have:
matiu#matiu-laptop:~/projects/cdnalizer/build/src/apache$ readelf -d mod_cdnalizer.so | grep NEED
0x0000000000000001 (NEEDED) Shared library: [libapr-1.so.0]
0x0000000000000001 (NEEDED) Shared library: [libstdc++.so.6]
0x0000000000000001 (NEEDED) Shared library: [libgcc_s.so.1]
0x0000000000000001 (NEEDED) Shared library: [libc.so.6]
0x000000006ffffffe (VERNEED) 0xd520
0x000000006fffffff (VERNEEDNUM) 3
build line:
/usr/bin/g++ -fPIC -I/usr/local/include -I/usr/include -I/usr/include/x86_64-linux-gnu -I/usr/include/x86_64-linux-gnu/c++/4.8 -Wall -Wextra -g -shared -Wl,-soname,mod_cdnalizer.so -o mod_cdnalizer.so CMakeFiles/mod_cdnalizer.dir/mod_cdnalizer.cpp.o CMakeFiles/mod_cdnalizer.dir/config.cpp.o CMakeFiles/mod_cdnalizer.dir/filter.cpp.o ../libbase.a -lapr-1
I have tried compiling gcc-4.8.2 on centos, but the binaries it produces have similar glibc dependencies:
[root#matt src]# ./test_config
./test_config: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.14' not found (required by ./test_config)
./test_config: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.15' not found (required by ./test_config)
I heard that you can't escape glibc dependencies for shared libraries because c++ throws excoptions and so needs the shared libstdc++ (but my lib doesn't throw exceptions across the library boundary).
I also heard that you can't link in glibc statically because the static lib was not compiled with -fPIC.
My main question is:
How can I distribute my c++11 shared library on centos6 ?
My sub questions are:
Can I compile a c++11 shared library on ubuntu 13.10, and have it load on centos6 (and older ubuntus) ? how ?
Can I compile a c++11 shared library on centos6 and have it work on standard centos installs ?
(Don't worry about Apache2.2 vs 2.4 dependency .. that's the easy bit)
Can I compile a c++11 shared library on centos6 and have it work on standard centos installs ?
If you can't build your code with the standard CentOS 6 g++/glibc/libstdc++, then no, it's not going to run on standard CentOS 6 installs.
The CentOS distro is for long term support (LTS). Critical bugs get fixed with updates, but software otherwise doesn't change, usually. This is a feature. Even with 3rd party repositories (e.g. EPEL), the available software for CentOS isn't really recent.
Can I compile a c++11 shared library on ubuntu 13.10, and have it load on centos6 (and older ubuntus) ? how ?
If you can compile it using the g++ 4.4 toolchain, sure. In this case, you cannot use a more advanced compiler. A quick search on Ubuntu's 12.04 LTS package list shows libstdc++6-4.5-dbg using a version of libstdc++.so.6 which would be backward incompatible, based on error messages above.
How can I distribute my c++11 shared library on centos6 ?
As you've shown above, you'll have at least one updated dependency (libstdc++.so.6) that you'll need to ship with your library, and install in some odd location, with it's attendant headaches (LD_LIBRARY_PATH, what happens to any other C++ plugins, etc.). And update at some point.
Some enterprise users would object to something like this, mainly because it doesn't mesh well with the existing OS.
Statically linking in dependencies (like in Ali's answer with the Developer Toolset below) could work also. It's also not without problems (updates to dependencies again), but might be the best chance for your code to work on CentOS 6.
I see from comments to Ali's answer, that devtools 1 (gcc 4.7.0) didn't work, making it unlikely that devtools 1.1 would work. So it seems you do need C++11 support up to the level of gcc 4.8 in this case.
Your problem has nothing to do with GLIBC.
Your problem is that libstdc++.so.6 on the CentOS6 is too old.
According to distrowatch, CentOS 6.5 shipped with GCC 4.4.7. C++11 support was mostly complete in GCC 4.8, and in 4.4 had only incomplete support.
If you can build your library with GCC 4.4.7, then it should work (provided you build it on an old enough system). If you can't, then you'll have to update GCC on your target CentOS system.
Alternatively, you can distribute a newer version of libstdc++.so.6 (one from GCC 4.8), install it in non-default location, and ask your customers to link against that newer version (either via LD_LIBRARY_PATH, or better by supplying appropriate -Wl,-rpath=... option at link time).
In short:
Things are only backward compatible. You need to pick the oldest
release of the distro you want to support and build on
that. The later releases of that distro will most likely be backward
compatible so your shared library will do just fine on later releases.
You either need to build the compiler with C++11 support from source or install it from some repo of the distro. Prefer the latter if possible due to compatibility issues.
Any non-system library should be statically linked into your shared
library: -Wl,--static -lmylib1 -lmylib2 -Wl,--dynamic. The important here is that -Wl,--dynamic is at the end, after all statically linked stuff.
I haven't tried it myself but my colleague who does this routinely says:
Use CentOS 6.5 (the latest of the 6.x versions as of writing).
Install devtools / Developer Toolset. The compatibility issues are supposed to be resolved by special, patched version of the developer tools. Developer Toolset 2.1 Beta comes with gcc 4.8.
Link statically all third party libraries and libstdc++. However, do not
link glibc and other system libraries statically that are supposed to be on the target machine
anyway.
The programs that my colleague compiles this way work on my Ubuntu machine just fine. (He uses CentOS 5.10, which seems to be the oldest, still supported distro that has glibc 2.5.)
Hope this helps.
I'm trying to build a portable version of gcc 4.8.2. (for only C/C++ languages) The end result is have gcc installed into a specific application directory, eg, /opt/gcc-4.8.2 so that I can copy that directory from one computer to another (all computers are either intel corei5 or corei7, running recent Linux versions, eg, Ubuntu 12, Suse 10/11, Centos 5 & 6).
So far I'm able to build gcc ok, using --prefix to have the gcc outputs placed in a single directory (which can then be later copied to the other hosts). I configured & built gcc's dependencies (gmp, mpfr, mpc, isl) to have --disable-shared, so I can be sure that the final gcc, when copied to other hosts, won't complain about missing libraries or symbols.
I have a question with cloog. I configured gcc with --with-cloog (to pick up my locally built cloog, which I built along with the other gcc dependencies). However, what I don't know, is whether I also need to copy the cloog libraries and binary to each host I copy gcc to?
Also, how can I test gcc & cloog interaction? Is there a simple C file example and/or gcc command line that can be used to test whether gcc is successfully making use of cloog?
Additionally, are there any other considerations when trying to build a gcc which I then want to run on other hosts?
It depends if cloog is installed as a shared library libcloog-isl.so.* or as a static one libcloog.a ; use
ldd $(gcc-4.8 -print-file-name=cc1)
to find out. Of course you need to install all the shared libraries dependencies. If libcloog*so appears in the output of above ldd command, it is a shared library. Otherwise a static one.
You could set the LD_LIBRARY_PATH, or add the directory containing libcloog-isl.so.* (e.g. /usr/local/lib/ or /opt/lib/ etc...) to /etc/ld.so.conf (then run ldconfig)
I am not entirely sure your gcc build can run on every platform you mentioned. There might be libc* dependencies. See this. And perhaps also binutils dependencies (notably for gcc-4.8 -flto compilations).
To test gcc just compile with optimizations (e.g. gcc-4.8 -Wall -O3) some non-trivial file.
I need to compile a libwebsocket library for my ARM target which requires openssl for its functioning.
I am getting following error when i build latest libwebsocket at the time of, cmake ...
But openssl is installed here
whereis openssl
openssl: /usr/bin/openssl /usr/bin/X11/openssl /usr/share/man/man1/openssl.1ssl.gz
=================================== Error ================
-- Looking for 4 include files stdlib.h, ..., float.h - found
-- Found ZLIB: /usr/lib/arm-linux-gnueabihf/libz.so (found version "1.2.7")
ZLib include dirs: /usr/include
ZLib libraries: /usr/lib/arm-linux-gnueabihf/libz.so
Compiling with SSL support
CMake Error at /usr/local/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:97 (message):
Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the
system variable OPENSSL_ROOT_DIR (missing: OPENSSL_LIBRARIES
OPENSSL_INCLUDE_DIR)
Call Stack (most recent call first):
/usr/local/share/cmake-2.8/Modules/FindPackageHandleStandardArgs.cmake:291 (_FPHSA_FAILURE_MESSAGE)
/usr/local/share/cmake-2.8/Modules/FindOpenSSL.cmake:313 (find_package_handle_standard_args)
CMakeLists.txt:436 (find_package)
-- Configuring incomplete, errors occurred!
======================================= openssl is here ========================
ignite#ignite:~/sbox2/rootfs/rfs-raspbian_2/home/pi/libwebsockets/build$ whereis openssl
openssl: /usr/bin/openssl /usr/bin/X11/openssl /usr/share/man/man1/openssl.1ssl.gz
actually i have, source tarball from here. it have configure script to make & make install
http://www.openssl.org/source/
openssl-1.0.1e.tar.gz
So with this (openssl-1.0.1e.tar.gz) will be the right package to get --> openssl-dev or openssl-devel --- so that i can resolve this error ?
So with this (openssl-1.0.1e.tar.gz) will be the right package to get --> openssl-dev or openssl-devel --- so that i can resolve this error ?
The openssl-dev packages are for development on the host machine (which is probably x86 or x64 family). You need a cross compiled library for the target (and not the host). So openssl-dev will probably not solve your problem.
Are you targeting a generic ARM processor, iOS, or Android? If the former, you will need an arm cross-toolchain with paths set appropriately. I'm not aware of a good tutorial on cross compiling the library (and I've suffered it in the past).
There are some prebuilt configurations for generic cross compiling. Open Configure and config, and look at some of the triples. (OpenSSL does not use Automake and friends).
If iOS or Android, the OpenSSL wiki has some examples of cross compiling for the platforms. See, for example, FIPS Library and Android. The setenv-android.sh script is most important because it set paths, sysroot and toolchains. Once paths and toolschains are set, the rest is easy.
If you are targeting a generic ARM, then you could use the Android setenv-android.sh as a starting point for your generic build. Once you complete the build, then point OPENSSL_ROOT_DIR into the install directory for ARM.
I want to compile wpa_supplicant using another version of openssl then the one installed on the build system.
To do this, I set these settings in the .config file:
CFLAGS += -I/custom-openssl/include
LIBS += -L/custom-openssl/lib
However, it is still linking against the default installed openssl version.
Your -L directive will be added to the end of the list of libraries to look for .so files during linking.
Instead, either control which directory the loader should look in while loading the binary (which can be compiled into the binary) or change the list of libraries to search using the LD_LIBRARY_PATH environment variable.
I also had to set LIBS_p. Everything else was fine.