Of late, facebook opensourced warp, C/C++ preprocessor.
https://github.com/facebook/warp
I'm trying to build it using dmd and stuck with some build errors.
I downloaded dmd.2.065.0.zip for dmd compiler - dmd2/linux/bin64/dmd
I also see a bunch of libraries, for example libphobos2.a
Then when I build warp, I see some errors from ld, that keep complaining that phobos2.a could not be found. I exported LD_LIBRARY_PATH to the dir where this library is stored but no luck.
I compiled in verbose mode, and it doesn't give more info.
Command:
/path/to//building_stuff/dmd2/linux/bin64/dmd -O -inline -release -ofwarp cmdline.d constexpr.d context.d directive.d expanded.d file.d id.d lexer.d loc.d macros.d main.d number.d outdeps.d ranges.d skip.d sources.d stringlit.d textbuf.d -v
Error excerpt:
function textbuf.Textbuf!char.Textbuf.length
function textbuf.Textbuf!char.Textbuf.resize
gcc warp.o -o warp -m64 -L/path/to/building_stuff/dmd2/linux/bin64/../lib64 -Xlinker --export-dynamic -l:libphobos2.a -lpthread -lm -lrt
/usr/bin/ld: cannot find -l:libphobos2.a
collect2: ld returned 1 exit status
--- errorlevel 1
I was hoping the D language experts here, or those who know about warp already could give me some hint.
I was not on CentOS, as warp demands. I wonder if that could anyway be the reason.
I was not using gcc 4.7.x as warp demands, but, to me, the library could just not be located doesn't look like a problem from old gcc I have.
I was on redhat5.5 machine with 4.1 gcc.
CentOS is basically a RedHat, so everything should work OK. As people commented, your real problem is the -l:libphobos2.a in your link line. Remember, GNU/Linux allows colons in file-names, so :libphobos2.a is a perfectly valid file, and GNU ld won't find it in the library search paths.
Note that they've added a make file to easy on your compilation, I managed to compile it using "make -j" and only editing the dmd command line in the make.
just rename "libphobos2.a" to "lib:libphobos2.a.a"
I faced a similar problem with ld version 2.17, but with version 2.20 this 'l:<libfilename>' kinda syntax works fine.
Related
While attempting to write a kernel in C++, I've run into a peculiar issue.
When prompting g++ to compile even a very basic C++ file statically and to binary, it simply keeps skipping over the static math library (libm.a), ultimately failing to compile.
Attempting to compile a simple C++ file:
test.cpp
int main() {
return 0;
}
using this g++ command:
g++ -static test.cpp -Wl,--oformat=binary
I receive the following error output:
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/11/../../../x86_64-linux-gnu/libm.a when searching for -lm
/usr/bin/ld: skipping incompatible /lib/x86_64-linux-gnu/libm.a when searching for -lm
/usr/bin/ld: skipping incompatible /usr/lib/x86_64-linux-gnu/libm.a when searching for -lm
/usr/bin/ld: skipping incompatible /lib/x86_64-linux-gnu/libm.a when searching for -lm
/usr/bin/ld: skipping incompatible /usr/lib/x86_64-linux-gnu/libm.a when searching for -lm
/usr/bin/ld: cannot find -lm: No such file or directory
I am running Linux Mint Cinnamon V. 21 (Vanessa) on a VirtualBox VM.
In my attempt to narrow down the issue, I have also attempted to exclude the -static flag:
g++ test.cpp -Wl,--oformat=binary
Which results in a different error entirely:
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/11/libstdc++.so: error adding symbols: file in wrong format
collect2: error: ld returned 1 exit status
After thorough research, I was made aware that this could be caused by an incompatibility between 32-bit libraries and 64-bit files. Everything is supposed to be in 64 bit.
I did attempt to determine bitness of libm.a using file.
When using the file command on /usr/lib/x86_64-linux-gnu/libm.a, I receive the following output:
libm.a: ASCII text
indicating neither bitness. This led me to conclude that perhaps the library is damaged and needs updating. After running sudo apt-get install libc6-dev, the issue persists, however.
I'm not sure what to do at this point.
Update:
I've opened libm.a in a text editor and the entire contents of the file are:
/* GNU ld script
*/
OUTPUT_FORMAT(elf64-x86-64)
GROUP ( /usr/lib/x86_64-linux-gnu/libm-2.35.a /usr/lib/x86_64-linux-gnu/libmvec.a )
Update 2: apparently this is a linker script. Both referenced files libm-2.35.a and libmvec.a are present in my directory and are, according to objdump, 64-bit-versions.
Based on the compiler's error output, it seems that in my case, for whatever reason, g++ (or more specifically, ld) fails to use this linker script. What could possibly cause this?
I have come to the conclusion that it is not normally possible to statically link C++ code involving object oriented features into a fully functional binary file, as libm.a can apparently be linked to ELF only.
besides: even the static version of glibc, which is also required, references other dynamic libraries, making it useless for kernel code.
there might be some sort of workaround, but it seems that g++ does not support this functionality by default.
I am cross-compiling gpsd3.20 on my Ubuntu 16.04 for the ARM architecture. As you may know, gpsd uses Sconsctruct to compile the source codes. During my cross-compilation, the moment when it needs to create the libgps.so it shows an error unrecognized option '-Wl, -Bsymbolic'.
Before posting the question here, I have tried t check my toolchain binaries and I found out that if I run this line manually:
sudo ./arm-v7a-linux-gnueabihf-ld -o test/gpsd-3.20/libgps.so.25.0.0 -pthread -shared -Wl,-Bsymbolic-functions -Wl,-soname=libgps.so.25 test/gpsd-3.20/os_compat.os test/gpsd-3.20/rtcm2_json.os test/rtcm3_json.os test/gpsd-3.20/shared_json.os test/gpsd-3.20/timespec_str.os test/gpsd-3.20/libgpsmm.os -L. -lrt -lm -lrt
The above commands print out the exact error as I mentioned previously. However, if I run the exact command replacing ld with gcc, then there is no any errors.
sudo ./arm-v7a-linux-gnueabihf-gcc -o test/gpsd-3.20/libgps.so.25.0.0 -pthread -shared -Wl,-Bsymbolic-functions -Wl,-soname=libgps.so.25 test/gpsd-3.20/os_compat.os test/gpsd-3.20/rtcm2_json.os test/rtcm3_json.os test/gpsd-3.20/shared_json.os test/gpsd-3.20/timespec_str.os test/gpsd-3.20/libgpsmm.os -L. -lrt -lm -lrt
Upon checking the arm-v7a-linux-gnueabihf-gcc --help, I found out that, gcc support -Wloptions whereas in the arm-v7a-linux-gnueabihf-ld it doesn't support the -Wl options. So now I am not sure how to change the SConstruct file so that it doesn't execute ld instead I want it to execute gcc especially for the libgps.so part.
(can't comment), so as answer: have you tried to set the env.-var.:
export LD=arm-v7a-linux-gnuabihf-gcc
Gcc takes -Wl,XXX and passes XXX to the linker.
I think you've got two combining problems here, though there's some guessing involved without looking into the build itself. First, scons shouldn't be adding the flag when building a library (https://github.com/SCons/scons/issues/3248 - fixed but, I believe, not part of a release). Second, "linking" should probably be done using gcc. If you call gcc to link, it still calls the linker behind the scenes - after dealing with options that are intended for gcc, which -Wl,-Bsymbolic is, it means pass -Bsymbolic on to the linking phase (indicated by -Wl, the 'l' meaning linker). So I'm supposing that the way you've told scons about the cross toolchain isn't quite right either, if it's calling ld directly you're probably going to have other issues as well.
I am trying to compile as this :
-bash-4.1$ g++ -static -m32 Hello.cpp
and getting errors like this:
/opt/rh/devtoolset-4/root/usr/libexec/gcc/x86_64-redhat-linux/5.2.1/ld: skipping incompatible /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.2.1/libstdc++.a when searching for -lstdc++
/opt/rh/devtoolset-4/root/usr/libexec/gcc/x86_64-redhat-linux/5.2.1/ld: cannot find -lstdc++
collect2: error: ld returned 1 exit status
I have tried this as well but still get the exact same error above:
g++ -static -m32 -L/opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.2.1/32 Hello.cpp
I have tried in both orders - nothing helps.
Why is it still looking at the wrong directory?
Is using -m32 option override -L option?
I could not find much documentation on -m32 option.
Please help.
Thanks!
Why is it still looking at the wrong directory?
Compiler always looking in predefined directories first. -L options adds your path to these list of directories, so because of it compiler is stil looking at the wrong directory. For more detailed output try to compiler your program with detailed output -### or -v options.
Is using -m32 option override -L option?
The answer is no - -m32 options is option to generate 32bit code, for example:
You may generate 32bit code that will work on 32bit machine, on your 64bit machine. Also you may run this code on your 64bit machine - it will work well.
I could not find much documentation on -m32 option.
Here is the link to the GCC docs
And here is doc about directory searching options
Also to say to compiler where to find libraries, you may set
LD_LIBRARY_PATH in your env
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$FULL_PATH_TO_YOUR_LIB
Do not override env vars - cause it may cause more problems if you are not absolutely sure in what you are doing.
I am trying to link Mathlink libraries in mathematica. I am using a x86_64-suse-linux OS, but when I check $SystemID in Mathematica, it tells me I am using 'Linux' instead of 'Linux-x86-64'.
This is a problem because if I try to link the library as
g++ cpp2mma.cpp -L/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux/CompilerAdditions/ -lML32i3 -lpthread -lstdc++ -lm -lrt
(the 32 bit version - and the only library in Linux/)
I get the following error:
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible
/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux/CompilerAdditions//libML32i3.so when searching for -lML32i3
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: skipping incompatible
/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux/CompilerAdditions//libML32i3.a when searching for -lML32i3
/usr/lib64/gcc/x86_64-suse-linux/4.5/../../../../x86_64-suse-linux/bin/ld: cannot find -lML32i3
collect2: ld returned 1 exit status
however, if I try to link it as
g++ cpp2mma.cpp -L/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions/ -lML64i3 -lpthread -lstdc++ -lm -lrt
it compiles just fine, but if I try to run it I get the following error:
./a.out: error while loading shared libraries: libML64i3.so: cannot open shared object file: No such file or directory
This file obviously exists as running 'locate libML64i3.so' yields:
/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Libraries/Linux-x86-64/libML64i3.so
/usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions/libML64i3.so
Am I correct in assuming that the problem lies in the fact that Mathematica thinks that I am not running a 32 bit system? If so, what do I do?
The problem is not in Mathematica. The kernel is never running -- from the perspective of e system you are compiling and launching an ELF executable. libML64i3 will start a kernel for you, but its not getting loaded here.
There are several ways to get the linker to find libML64i3.so at runtime
Export the directory containing libML64i3.so through LD_LIBRARY_PATH (generally not a good idea)
use an entry in /etc/ld.so.conf.d or /etc/ld.so.conf to indicate that /usr/local/Wolfram/Mathematica/8.0/SystemFiles/Links/MathLink/DeveloperKit/Linux-x86-64/CompilerAdditions should be part of the library search path -- look at ldconfig(8).
Symlink libML64i3.so somewhere already in the library search path
Link to a static version of libML, as described in this StackOverflow post.
To deal with the compile-time linker errors, you could compile your application 32-bit (by passing -m32 to g++). If you did this, you would get a runtime message griping about not being able to find the 32-bit version of libML, which would require the same solution as above.
I'm not sure why $SystemID is returning a value indicating you are running the 32-bit kernel. That probably has something to do with how you are starting Mathematica. On CentOS 5-7-x86_64, I have
host 11% ls -l $(which math)
lrwxrwxrwx 1 root root 51 Nov 8 16:27 /usr/local/bin/math -> \
/usr/local/Wolfram/Mathematica/8.0/Executables/math
host 12% math
Mathematica 8.0 for Linux x86 (64-bit)
Copyright 1988-2011 Wolfram Research, Inc.
In[1]:= $SystemID
Out[1]= Linux-x86-64
On OSX 10.6.4 with i686-apple-darwin10-g++-4.2.1 compiling using TextMate and a Makefile which in the first place has been made für a Linux and I am trying to translate for OSX.
When compiling a c++ project I get the "can't link with a main executable" error:
g++ -Wall -g -I ~/svnX-Repository/axp-Projekte/xrlfupa/trunk/src/ -I ~/svnX-Repository/boost_1_44_0 -I /opt/local/var/macports/software/boost/1.44.0_0/opt/local/lib/ -I /opt/local/var/macports/software/gsl/1.14_0/opt/local/include/ -o xrfLibTest xrfLibTest.o excitFunctions.o xrfFunctions.o filterFunctions.o detectorFunctions.o -L/opt/local/var/macports/software/boost/1.44.0_0/opt/local/lib/ -L/opt/local/var/macports/software/gsl/1.14_0/opt/local/lib/ -lm -lxrlTUB -lboost_serialization -lgsl -lgslcblas # Debug 1
ld: in /usr/local/lib/libxrlTUB.so, can't link with a main executable
collect2: ld returned 1 exit status
make: *** [prog] Error 1
The library that is mentioned (libxrlTUB.so) is in its place (/usr/local/lib/libxrlTUB.so) but, possibly that is where the problem came from, the libxrlTUB.so has been compiled by myself beforehand as well.
The compile process went through, it was generated by swig, though there was a warning:
g++ -arch x86_64 -m32 -g -fpic -I /usr/include/python2.6 -c PyXrl_wrap.cxx
In function 'void SWIG_Python_AddErrorMsg(const char*)':
warning: format not a string literal and no format arguments
which, as far as I could find out, shouldnt be a problem. (Or is it?)
Unfortunately this whole thing is part of a project from the university. Actually I am supposed to write an X-ray-analysis script in python, which would be fine, if... well if I wouldn't be expected to use the librarys that are meant to result from this c++ project.
(Afterwards they should be used via import in python.)
I am not really experienced with c++, neither with compiling on OSX systems. So far I have been bothering with scipting (python, bash, etc). So Maybe I am just missing something simple. Hopefully someone can give me an hint where I can continue reading in order to deal with the above "can't link with a main executable" error...
Thanx in advance,
Liam
The error message is telling you the problem—it is that /usr/local/lib/libxrlTUB.so is not a shared library; it's an executable. You can't link against an executable. Probably whatever build process you used for libxrlTUB.so didn't understand how to build shared libraries on the Mac (it's more suspect because .dylib is the correct extension to use.)
Take a look at Apple's documentation on compiling dynamic libraries. You can use file to make sure your output is of the correct type, for example:
% gcc -c foo.c
% gcc -dynamiclib foo.o -o foo.dylib
% file foo.dylib
foo.dylib: Mach-O 64-bit dynamically linked shared library x86_64
Without -dynamiclib you end up with an executable, which may be the problem you've run into.