Undefined reference to `libbgp::BgpFsm::tick()' - c++

I started working with c++ a few weeks ago, and I started a new project to start learning more. I'm encountering an issue with an external dependency. I'm trying to use a library called:
libbgp, and I installed it base on their documentation.
Here is my code:
https://gist.github.com/amb1s1/9b2c72294da0ec9416810c8686d3adce
Error:
/usr/bin/ld: /tmp/ccsdO32O.o: in function `ticker(libbgp::BgpFsm&)':
ambgp.cpp:(.text+0xa7): undefined reference to `libbgp::BgpFsm::tick()'
collect2: error: ld returned 1 exit status
I'm not sure if there is anything else that I have to do after installing the lib for the library to be accessible in my source code.
Update
I ran it with the -lbgp flag and when running it, i get the following error:
g++ -lbgp ambgp.cpp -o ambgp
Error:
./ambgp: error while loading shared libraries: libbgp.so.0: cannot open shared object file: No such file or directory
My Lib:
ls -l /usr/local/lib/
-rw-r--r-- 1 root root 10875880 Jan 18 16:56 libbgp.a
-rwxr-xr-x 1 root root 924 Jan 18 16:56 libbgp.la
lrwxrwxrwx 1 root root 15 Jan 18 16:56 libbgp.so -> libbgp.so.0.0.0
lrwxrwxrwx 1 root root 15 Jan 18 16:56 libbgp.so.0 -> libbgp.so.0.0.0
-rwxr-xr-x 1 root root 4291128 Jan 18 16:56 libbgp.so.0.0.0
drwxrwsr-x 3 root staff 4096 Dec 16 19:27 python3.7
echo $LD_LIBRARY_PATH
:/usr/local/lib

Before running the executable, you have to tell it where to find the libgdp.so file, if it is not stored in a standard place such as /usr/lib or /lib. Following should help you:
$ export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:/usr/local/lib"
$ ./ambgp
If you do not want to export the LD_LIBRARY_PATH each time you start the shell manually, add the line to your /home/<user>/.bashrc file.
Additionally, i think the -lbgp flag should go after the source file in the compiler command (g++ ambgp.cpp -lbgp -o ambgp)
TL;DR :
ld states it cannot find libbgp.so.0, and you wrote in the comments that you found libbgp.so without a trailing .0. So, creating a symlink to the library could help too:
$ sudo ln -s /usr/local/lib/libbgp.so /usr/local/lib/libbgp.so.0
For linking, you need a library file without a trailing .0, but for loading, the library name must have a trailing .0.
The last thing to try is to directly specify the library location to the linker with -Wl,-rpath=/usr/local/lib (as you worked out already !)

Related

"string.h" not found message in building qt app for iOS

I've recently updated Xcode to version 10.0 and after that when I try to build version for iOS I've the following problem.
1:04:17: Running steps for project Diasteca...
11:04:17: Starting: "/Users/belladellifabio/Qt/5.11.1/ios/bin/qmake" /Users/belladellifabio/Desktop/QtProjects/Diasteca/mqtt_test/mqtt_test.pro -spec macx-ios-clang CONFIG+=iphoneos CONFIG+=device CONFIG+=qml_debug
Project MESSAGE: This project is using private headers and will therefore be tied to this specific Qt module build version.
Project MESSAGE: Running this project against other versions of the Qt modules may crash at any arbitrary point.
Project MESSAGE: This is not a bug, but a result of using Qt internals. You have been warned!
11:04:18: The process "/Users/belladellifabio/Qt/5.11.1/ios/bin/qmake" exited normally.
11:04:18: Starting: "/usr/bin/make" qmake_all
make: Nothing to be done for `qmake_all'.
11:04:18: The process "/usr/bin/make" exited normally.
11:04:18: Starting: "/usr/bin/make"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -c -pipe -stdlib=libc++ -g -fPIC -std=gnu++11 -arch arm64 -arch x86_64 -Xarch_arm64 -miphoneos-version-min=12.0 -Xarch_arm64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk -Xarch_x86_64 -mios-simulator-version-min=12.0 -Xarch_x86_64 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.3.sdk -fobjc-nonfragile-abi -fobjc-legacy-dispatch -fembed-bitcode-marker -Wall -W -DQT_COMPILER_SUPPORTS_SSE2 -DMQTT_TEST_LIBRARY -DQT_DEPRECATED_WARNINGS -DQT_QML_DEBUG -DQT_NETWORK_LIB -DQT_CORE_LIB -I../../Diasteca/mqtt_test -I. -I../../../../Qt/5.11.1/ios/mkspecs/common/uikit -I../../../../Qt/5.11.1/ios/include -I../../../../Qt/5.11.1/ios/include/QtNetwork -I../../../../Qt/5.11.1/ios/include/QtCore/5.11.1 -I../../../../Qt/5.11.1/ios/include/QtCore/5.11.1/QtCore -I../../../../Qt/5.11.1/ios/include/QtCore -I. -I../../../../Qt/5.11.1/ios/mkspecs/macx-ios-clang -o qmqttclient.o ../../Diasteca/mqtt_test/qmqttclient.cpp
clang: warning: no such sysroot directory: '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.3.sdk' [-Wmissing-sysroot]
clang: warning: no such sysroot directory: '/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator11.3.sdk' [-Wmissing-sysroot]
In file included from ../../Diasteca/mqtt_test/qmqttclient.cpp:30:
In file included from ../../Diasteca/mqtt_test/qmqttclient.h:33:
In file included from ../../Diasteca/mqtt_test/qmqttglobal.h:33:
In file included from ../../../../Qt/5.11.1/ios/include/QtCore/qglobal.h:47:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/utility:202:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/cstring:61:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/string.h:61:15: fatal error: 'string.h' file not found
Probably the real problem is not the file not found error, but is connected to the fact that qty tries to build the app using an SDK that is no more installed on the system. Is this a qt problem? How could I specify the version of iOS SDK to use to build the app? Is it possible?
Finally, I've found and delete .qmake.cache and .qmake.stash files. I've restart QtCreator and now it seems to work.
Qt stores SDK information somewhere deep in the build output and the .pro.user file.
Remove the user file (you might want to backup your user file in case you have custom build steps), the complete (shadow) build tree and modify your .pro file so that there is no such line as QMAKE_MAC_SDK = macosx10.13.
Then call qmake and build your project again, the inconsistency should be gone.
This occurs when the iOS SDK that Qt is expecting is different than the iOS SDK that you have installed. For instance Qt 5.13.1 expects iPhoneOS13.1.sdk but my Xcode currently has iPhoneOS13.2.sdk:
$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs
$ ls -l
total 0
drwxrwxr-x 7 root wheel 224 Nov 5 2019 iPhoneOS.sdk
lrwxr-xr-x 1 root wheel 12 Jan 15 2020 iPhoneOS13.2.sdk -> iPhoneOS.sdk
$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs
$ ls -l
total 0
drwxrwxr-x 8 root wheel 256 Jul 22 14:14 iPhoneSimulator.sdk
lrwxr-xr-x 1 root wheel 19 Jan 15 2020 iPhoneSimulator13.2.sdk -> iPhoneSimulator.sdk
To remedy this, we can get Qt to use the iPhoneOS13.2.sdk:
$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs
$ ls -l
total 0
drwxrwxr-x 7 root wheel 224 Nov 5 2019 iPhoneOS.sdk
lrwxr-xr-x 1 root wheel 12 Jan 15 2020 iPhoneOS13.2.sdk -> iPhoneOS.sdk
$ sudo ln -s iPhoneOS.sdk iPhoneOS13.1.sdk
$ ls -l
total 0
drwxrwxr-x 8 root wheel 256 Jul 22 14:20 iPhoneOS.sdk
lrwxr-xr-x 1 root wheel 12 Jul 22 14:20 iPhoneOS13.1.sdk -> iPhoneOS.sdk
lrwxr-xr-x 1 root wheel 12 Jan 15 2020 iPhoneOS13.2.sdk -> iPhoneOS.sdk
$ cd /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs
$ ls -l
total 0
drwxrwxr-x 8 root wheel 256 Jul 22 14:14 iPhoneSimulator.sdk
lrwxr-xr-x 1 root wheel 19 Jan 15 2020 iPhoneSimulator13.2.sdk -> iPhoneSimulator.sdk
$ sudo ln -s iPhoneSimulator.sdk iPhoneSimulator13.1.sdk
$ ls -l
total 0
drwxrwxr-x 8 root wheel 256 Jul 22 14:14 iPhoneSimulator.sdk
lrwxr-xr-x 1 root wheel 19 Jul 22 14:39 iPhoneSimulator13.1.sdk -> iPhoneSimulator.sdk
lrwxr-xr-x 1 root wheel 19 Jan 15 2020 iPhoneSimulator13.2.sdk -> iPhoneSimulator.sdk
I met a similar problem, because my xcode project was created by different XCode SDK, and it's generated by CMake, so I deleted the cache and solved the problem.

Linkage error with Boost Log 1.65.0 example from the Boost.org

I tried to build this example and got a linkage error:
hekto#ubuntu:~$ g++ -g -Wall -std=c++11 -pthread -DBOOST_LOG_DYN_LINK -pthread sample.cpp -o sample -lboost_log -lboost_thread -lboost_system
/tmp/cc2EUizv.o: In function `boost::log::v2_mt_posix::basic_formatter<char> boost::log::v2_mt_posix::parse_formatter<char>(char const*)':
/usr/include/boost/log/utility/setup/formatter_parser.hpp:207: undefined reference to `boost::log::v2_mt_posix::basic_formatter<char> boost::log::v2_mt_posix::parse_formatter<char>(char const*, char const*)'
collect2: error: ld returned 1 exit status
How to overcome that?
I'm answering my own question, following the #Praetorian help and suggestion.
The Boost Log relies on two libraries (I thought it was only one):
hekto#ubuntu:~$ ls -l /usr/lib/x86_64-linux-gnu/libboost_log*
-rw-r--r-- 1 root root 3510082 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log.a
-rw-r--r-- 1 root root 2441460 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log_setup.a
lrwxrwxrwx 1 root root 28 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log_setup.so -> libboost_log_setup.so.1.65.1
-rw-r--r-- 1 root root 671944 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log_setup.so.1.65.1
lrwxrwxrwx 1 root root 22 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log.so -> libboost_log.so.1.65.1
-rw-r--r-- 1 root root 905752 Mar 6 2018 /usr/lib/x86_64-linux-gnu/libboost_log.so.1.65.1
If you compile and link on Linux, you'll have to provide a list of Boost libraries on the command line. According to an answer to this question, given by the main developer (#AndreySemashev) of the Boost Log, these libraries on the command line should look like this:
-lboost_log_setup -lboost_log
Probably it makes sense to provide two libraries instead of one (for example, when you link statically), but I couldn't find any recommendations about when we should use a single library, and when - both of them.

C++ compiler cannot find Boost libraries even after installing them

While compiling few test applications, I get the following error:
g++: error: −lboost_system: No such file or directory
g++: error: −lboost_filesystem: No such file or directory
while running the following command:
g++ -I/usr/include/boost/ -L/usr/lib/x86_64-linux-gnu/ aescuda.cpp -o test.o −lboost_system −lboost_filesystem
The libraries are installed and present in location as shown below:
<prompt>$ ll /usr/lib/x86_64-linux-gnu/libboost_system.*
-rw-r--r-- 1 root root 49178 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_system.a
lrwxrwxrwx 1 root root 25 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_system.so -> libboost_system.so.1.54.0
-rw-r--r-- 1 root root 14536 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_system.so.1.54.0
<prompt>$ ll /usr/lib/x86_64-linux-gnu/libboost_filesystem.*
-rw-r--r-- 1 root root 217628 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_filesystem.a
lrwxrwxrwx 1 root root 29 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_filesystem.so -> libboost_filesystem.so.1.54.0
-rw-r--r-- 1 root root 88936 Jun 20 2014 /usr/lib/x86_64-linux-gnu/libboost_filesystem.so.1.54.0
Can anyone suggest where am I going wrong :(
You have a wrong character in front of the l:
−lboost_system
It should be an ASCII hyphen:
-lboost_system
This causes the compiler driver to treat the whole string as an input file name (which obviously does not exist, hence the No such file or directory error), and not as an option to be passed to the linker.
(Perhaps consider switching the terminal font.)

Vim can't find C++ libavformat/libavutil library (No such file or directory)

Loading up the omxplayer.cpp file in vim and it gives me the following error:
omxplayer.cpp|34 col 34| fatal error: libavformat/avformat.h: No such file or directory
This is where the problem is occurring
#include <libavformat/avformat.h>
#include <libavutil/avutil.h>
But I know the files exist:
$ ls -l /usr/lib/libavu*
lrwxrwxrwx 1 root root 28 2013-11-08 13:46 /usr/lib/libavutil.so -> /usr/lib/libavutil.so.51.7.0
lrwxrwxrwx 1 root root 19 2012-06-13 12:38 /usr/lib/libavutil.so.51 -> libavutil.so.51.7.0
-rw-r--r-- 1 root root 117212 2012-06-13 12:38 /usr/lib/libavutil.so.51.7.0
$ ls -l /usr/lib/libavf*
lrwxrwxrwx 1 root root 30 2013-11-08 13:29 /usr/lib/libavformat.so -> /usr/lib/libavformat.so.53.3.0
lrwxrwxrwx 1 root root 21 2012-06-13 12:38 /usr/lib/libavformat.so.53 -> libavformat.so.53.3.0
-rw-r--r-- 1 root root 1053000 2012-06-13 12:38 /usr/lib/libavformat.so.53.3.0
And ldconfig can also find them:
$ ldconfig -p | grep libavformat && ldconfig -p | grep libavutil
libavformat.so.53 (libc6, hwcap: 0x0008000000008000) => /usr/lib/i686/cmov/libavformat.so.53
libavformat.so.53 (libc6) => /usr/lib/libavformat.so.53
libavutil.so.51 (libc6, hwcap: 0x0008000000008000) => /usr/lib/i686/cmov/libavutil.so.51
libavutil.so.51 (libc6) => /usr/lib/libavutil.so.51
I have read somewhere that ldconfig is for run time whereas ld is for build time, however, in this case I know the libraries are there in /usr/lib, therefore, what could be causing this problem?
omxplayer.cpp|34 col 34| fatal error: libavformat/avformat.h: No such file or directory
Error message says all: It is not in library, But it is header file which is not found.
Normal location is /usr/include/libavformat.
first check by command whether header location is included by g++ -v omxplayer.cpp, This command will show what all directories are included for header files.
if it dows not show directory containing specified header then you need to specify it's location in g++ -Ipath/to/headers omxplayer.cpp. command.

How do I make Boost multithreading?

I am trying to compile the latest Boost c++ libraries for Centos. I 've used bjam install and it has placed the libraries in /usr/lib and /usr/lib64.
The problem is I need the -mt variants for a specific application to run. I cannot understand in the documentation how to create the multithreading variants. :(
Please give me a hint!
Thanks!
-mt is just distribution specific extension.
either edit your config file or create symbolic link to libboost_thread
andrey#localhost:~$ ls -l /usr/lib/libboost_thread*
-rw-r--r-- 1 root root 174308 2010-01-25 10:36 /usr/lib/libboost_thread.a
lrwxrwxrwx 1 root root 41 2009-11-04 10:10 /usr/lib/libboost_thread-gcc41-mt-1_34_1.so.1.34.1 -> libboost_thread-gcc42-mt-1_34_1.so.1.34.1
-rw-r--r-- 1 root root 49912 2008-11-01 02:55 /usr/lib/libboost_thread-gcc42-mt-1_34_1.so.1.34.1
lrwxrwxrwx 1 root root 17 2010-01-27 18:32 /usr/lib/libboost_thread-mt.a -> libboost_thread.a
lrwxrwxrwx 1 root root 25 2010-01-27 18:32 /usr/lib/libboost_thread-mt.so -> libboost_thread.so.1.40.0
lrwxrwxrwx 1 root root 25 2010-01-27 18:32 /usr/lib/libboost_thread.so -> libboost_thread.so.1.40.0
-rw-r--r-- 1 root root 89392 2010-01-25 10:36 /usr/lib/libboost_thread.so.1.40.0
You can build all variations of the boost binary libraries using the --build-type=complete option. For example:
bjam --build-type=complete stage
This will put all library files into <your boost dir>/stage/lib/