I've been having some difficulty compiling a piece of C++ code for the physics engine Bullet Physics, and was hoping to get some advice.
This is my first time using gcc as a compiler, and including directories for compiling in general, so I'm going to give my whole process of problem-solving because I'm not sure where I went wrong or what the pertinent information is.
When I first tried to compile the code I got a fatal error about "No such error or directory", so I decided to add the directory with the -I option (1). It fixed the first error, but another popped up. Again, I was able to make the error go away with a -I option to the directory needed(2).
Then I got a whole long list of errors like the following:
main.cpp:(.text+0x33): undefined reference to 'RagdollDemo::initPhysics()'
main.cpp:(.text+0x84): undefined reference to 'glutmain(int, char**, int, int, char const*, DemoApplication*)'
/tmp/cc4MqhHm.o: In function '__static_initialization_and_destruction_0(int, int)':
main.cpp:(.text+0xe7): undefined reference to `std::ios_base::Init::Init()'
I tried a few different things, but the solution ended up using my home bullet folder (or usr/local/include/bullet/) with the --sysroot option (3).
This created a lot of errors for the C++ header files, and then I linked to a few more directories with -I (4-5), but at after one of the added directories the same set of errors that I thought I solved with the --sysroot addition popped up again (6).
I can't tell what to do now. I would guess that declaring the bullet folder as my root makes it impossible for the compiler to find the required C++ files in my actual root directories, but I don't what to do about that... and when I tried including the C++ files I needed, the compiler seemingly forgot I told it to use bullet as my root.
Final compilation I tried before I gave up and realized asking for help might be better than spending 3 hours looking at documentation without any idea of what the exact problem is. Numbers correspond to the steps above.
gcc
(3)--sysroot=/home/josh/bullet-2.82-r2704/
(1)-isystem/home/josh/bullet-2.82-r2704/Demos/OpenGL/
(2)-isystem/home/josh/bullet-2.82-r2704/src/
(4)-I/usr/include/
(5)-I/usr/include/c++/4.8
(6)-I/usr/include/x86_64-linux-gnu/c++/4.8/
./main.cpp
I'm using Ubuntu 14.04 LTS and my OS and emacs 24.3.1 as my IDE.
Any help would be greatly appreciated.
Best,
Josh
What you are seeing is not include issue. Linker is failing to link with symbols. You need to link with proper library, for example lglut
Related
TL,DR:
Is there a way for me (no root access) to make the linker (invoked by gcc) unaware of the contents of a directory contained in /etc/ld.so.conf after it has been cached via ldconfig?
In Detail:
I'm trying (and failing) to compile HTCondor on a custom linux distro without root access. For various reasons (see below) I believe that the problems I encounter are related to the fact that there are two versions of libssl and two versions of libcrypto installed on this machine. The newer version (1.0.0) of each of these is located at /usr/lib64 and an older version (0.9.8) is kept at /usr/local/lib64 for compatibility reasons. /etc/ld.so.conf contains both of these paths, so the linker knows about both.
During compilation I get an error
../condor_utils/libcondor_utils_8_7_9.so: undefined reference to `ERR_remove_thread_state'
since, for some reason, libcondor_utils_8_7_9.so is linked against libcrypto.so.0.9.8, while ERR_remove_thread_state was introduced in 1.0.0. It appears exactly once in the source code:
#if OPENSSL_VERSION_NUMBER < 0x10000000L
ERR_remove_state( 0 );
#elif OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
ERR_remove_thread_state( 0 );
#endif
so the preprocessor seems to make its decision based on version 1.0.0.
This question made me aware of this blog post, so I tried surrogating cpp with the following script:
#!/bin/bash
/usr/bin/gcc -Wl,-rpath-link="/usr/lib64",-rpath="/usr/lib64" "$#"
to no avail, unfortunately.
Just for the heck of it, I also tried commenting the prepocessor directives in the source code snippet above to force the selection of ERR_remove_state. This results in the linker warning me that libssl.so.1.0.0 may conflict with libssl.so.0.9.8 and, unsurprisingly, produces another "undefined reference" error.
EDIT:
The problem turned out not to be related to the linker at all. See my answer. However, out of curiosity, I'll leave the question open to see if anyone has a solution for it in its original formulation.
The comments by #user463035818 and #jww pointed me in the right direction to solve my specific problem, which turned out not be related to the linker directly.
Condor uses cmake as build system, so obviously it makes more sense to try to solve this at the cmake level (n00b here). Somewhere in the depths of all the things cmake does it finds both versions of the libraries and mixes them up for some reason. Invoking find_library with a specific version as per this answer in the main CMakeLists.txt solves that problem although it leaves a bad taste of dirty workaround in my mouth.
Making cmake ignore a certain directory when looking for libraries should not be hard, according to the docs. I haven't tried it, though.
I'm trying to build headless blackcoin from source on Windows 8 with mingw 6.3
and I got the following error: .../src/leveldb/libleveldb.a(env_win.o):env_win.cc:(.text+0xaff): undefined reference to '_imp__PathFileExistsW#4'
This function is mentioned here https://msdn.microsoft.com/en-us/library/windows/desktop/bb773584(v=vs.85).aspx
I would appreciate if someone can help me.
P.S. I linked the appropriate library.
Finally I was able to build it. Probably it is obvious for thoose guys who down voted the question. I simply answer since it might save time to somebody.
I relied on the Makefile which is a part of the project source code. Required library (shlwapi) present in the file so I was confused when it failed to build. Everything went well when I placed the library at the end of the linked files.
It was something like this
g++ ... -o -lshlwapi... /src/leveldb/libleveldb.a /src/leveldb/libmemenv.a
And became this
g++ ... -o /src/leveldb/libleveldb.a /src/leveldb/libmemenv.a -lshlwapi
Recently I found an example of how to use the expect library in C++. I tried to compile it, but the compiler (g++) said, that tcl8.5/expect.h doesn't exists. So I tried to include tcl8.6/expect.h - still the same error. I checked the /usr/include/ directory and I wasn't surprised when I've noticed, that there is no tcl8.x directory.
I've searched for files with "expect" in their name. Here's what I found:
/usr/include/expect_tcl.h
/usr/include/expect_comm.h
/usr/include/expect.h
Unfortunately when I tried to include any of these I got the following list of errors during compilation:
> g++ test.cpp -Wall -std=c++0x -ltcl8.6 -lglog -o test
/tmp/cce8k1BA.o: In function `task(std::string const&, std::string const&, std::string const&)':
test.cpp:(.text+0x16): undefined reference to `exp_is_debugging'
test.cpp:(.text+0x20): undefined reference to `exp_timeout'
test.cpp:(.text+0x38): undefined reference to `exp_popen'
etc...
How can I solve this problem?
[EDIT]
When I tried to link it with the expect lib (-lexpect) I got the following error:
/usr/bin/ld: cannot find -lexpect
collect2: error: ld returned 1 exit status
I'm sure that both - tcl8.6 and expect 5.45-4 are installed.
The usual way of distributing Expect these days puts the shared library in a non-standard location and loads it dynamically by full pathname. This works well and is minimal fuss for most people, but does make it rather hard to use Expect's C interface in your own code.
The easiest way is going to be to build your own copy from source, especially as that will give you control over how exactly it was built. This can particularly include keeping the majority of symbols in the library instead of stripping them on install, which will help a lot with debugging. You probably ought to use the current supported version. (Yes, it's a release from several years ago. It doesn't need a lot of support effort most of the time.)
You haven't linked to the expect library during your build. Add -lexpect to your g++ command.
This maybe really stupid, but I faced the following error, while trying to compile certain code modules, using cmake
acg_localizer_active_search.cc:(.text+0x43c6): undefined reference to
`ANNkd_tree::ANNkd_tree(float**, int, int, int, ANNsplitRule)'
acg_localizer_active_search.cc:(.text+0x4441): undefined reference to
`ANNkd_tree::ANNkd_tree(float**, int, int, int, ANNsplitRule)'
Please help me to understand what this undefined reference error means.
The error line mentioned as '.text+0x...', is not understandable. How can I locate the error.
I have been stuck for quite some time, solving error after error and have ended up here. Please help me. Thanks in advance
Sorry for not adding the code. it is around 2000 lines and am not sure where to locate this error. its part of a software package, called acg_localizer.
That's a link time error. The method ANNkd_tree::ANNkd_tree(float**, int, int, int, ANNsplitRule) cannot be found in any libraries and object files specified in the link command, although it is referenced.
You have to find out where it is defined, and make sure the library it is defined in comes after the library that uses it on the linker command line.
You can use the nm tool to find out which symbols (= variables, methods) are defined or used by an object file or library. Do a man nm (or search on google) to find out more.
I'm trying to build a simple unit test executable, using cpputest. I've built the cpputest framework into a static library, and am now trying to link that into an executable. However, I'm tied into a fairly complicated Makefile setup, because of the related code.
This is my command line:
/usr/bin/qcc -V4.2.4,gcc_ntoarmle_acpp-ne -lang-c++ -O2 -g -g -o Application/UnitTests/Tests/symbols/UnitTestExe -Wl,--start-group Application/UnitTests/Tests/../.objs/main.o Application/UnitTests/lib/libcpputest.a -Wl,--end-group -lm
I'm getting many errors like the following:
Application/UnitTests/lib/libcpputest.a(CommandLineTestRunner.o): In function `CommandLineTestRunner::parseArguments(TestPlugin*)':
Application/UnitTests/cpputest/src/CppUTest/.objs/../CommandLineTestRunner.cpp:114: undefined reference to `operator new(unsigned int, char const*, int)'
I can't figure out what's causing this. Don't I get operator new for free with C++?
You probably need to link with the C++ support runtime library. This happens automatically when you invoke g++. On Linux, this is achieved by adding the -lstdc++ flag to the linker. You have to figure out how to do the same on your platform.
Maybe you're calling gcc, the C compiler instead of g++, which is the C++ compiler.
There's very little information in your question to work from, but it looks like some code uses some form of placement new, and while that special operator new is declared (the compiler finds it and compiles the code using it), the linker can't find its definition.
(Since this old answer of mine seems to still get attention: See here for an extensive discussion on declaration vs. definition.)
You need to rebuild your code from scratch, including the library. I got this error because I inadvertently copied object files compiled on another machine (with the rest of the source) to my machine. Most likely this disturbs the linking step since there are now two types of object files, native (for modified source files) and non-native (all others). I am guessing here, but the operator 'new' means slightly different things on different architectures and that's why you are getting this error.
p.s. I know this is way too late for a useful answer but I'm still posting this for the record.
For QNX 6.5.0 I have specified flag -lang-c++ for qcc (gcc) to avoid the error.
Like the original post, in my case this error happened while trying to link a software using CppUTest framework.
In my case, the source of the problem seems to be related to the fact I disabled the MEMORY_LEAK_DETECTION compile option of CppUTest. I enabled it again, which solved the problem.
Sometimes adding -lstdc++ is not enough. You should add it to the right place. For example I had list like this, not working:
target_link_libraries(cfr2 pthread m stdc++ "${CMAKE_SOURCE_DIR}/compressor/libcompressor.a" )
But this one works fine:
target_link_libraries(cfr2 pthread m "${CMAKE_SOURCE_DIR}/compressor/libcompressor.a" stdc++)
It'd be great if someone explained it in the comment section.