mingw g++ is unable to link with libraries - c++

I'm trying to use X86_64-w64-mingw32-g++ (packaged in Archlinux's MingW package) to cross compile some C++ code into an Windows executable, however I'm having trouble getting past some issues.
I'm calling
x86_64-w64-mingw32-g++ -o build_win/asm build_win/asm.o build_win/asm_lib.o build_win/socket_boost.o -I../extra/etc -fopenmp -lrt -std=c++11 -g -lboost_system -lboost_serialization
from a makefile, but I get thrown the errors:
/usr/lib/gcc/x86_64-w64-mingw32/5.1.0/../../../../x86_64-w64-mingw32/bin/ld: cannot find -lrt
/usr/lib/gcc/x86_64-w64-mingw32/5.1.0/../../../../x86_64-w64-mingw32/bin/ld: cannot find -lboost_system
/usr/lib/gcc/x86_64-w64-mingw32/5.1.0/../../../../x86_64-w64-mingw32/bin/ld: cannot find -lboost_serialization
This works fine with native g++, so exactly do I have to change for mingw to compile?
EDIT: I have mingw-w64-boost package installed, which includes boost libraries pre-compiled and ready to be linked. However, it seems the naming convention is a bit different, and -lboost_system for example becomes -llibboost_system-mt (not exactly sure what the -mt suffix entails).
Problem is I can't find the mingw counterpart for -lrt. I've tried with both -lrtm and -lrtutils but in both cases I get:
[...]
undefined reference to `__imp_getsockopt'

Are you sure that -lboost_system and other libraries are present in the same directory as makefile ?
If not then please include -L flag which indicates the location of your library.
For example:
-L /path_openmp -fopenmp -L /path_boost_system/ -lboost_system -L /path_serialization -lboost_serialization
Moreover, you need not include -I and -g flag when creating an executable from .o files. These are needed when you create .o from .cpp files.

There is no rt library on Windows.
You are missing -lws2_32.
$ x86_64-w64-mingw32-nm -A /usr/x86_64-w64-mingw32/lib/*.a 2>/dev/null | grep getsockopt | grep " T "

Related

g++ can't find ncurses.h despite it being installed

I'm trying to experiment around in ncurses for the first time, but I'm having problems compiling my source code. As far as I can tell, ncurses is installed and in the proper directories.
My makefile is super simple:
.cpp :
g++ -Wall -g -o $* $*.cpp -std=c++11 -lncurses
and here's my output when I try to locate ncurses.h
$ locate ncurses.h
/usr/include/ncursesw/ncurses.h
and when I check to see if it's installed
$ dpkg -l | grep ncurses
ii libncurses5:amd64 5.9+20140118-1ubuntu1 amd64 shared libraries for terminal handling
ii libncursesw5:amd64 5.9+20140118-1ubuntu1 amd64 shared libraries for terminal handling (wide character support)
ii libncursesw5-dev:amd64 5.9+20140118-1ubuntu1 amd64 developer's libraries for ncursesw
ii mtr-tiny 0.85-2 amd64 Full screen ncurses traceroute tool
ii ncurses-base 5.9+20140118-1ubuntu1 all basic terminal type definitions
ii ncurses-bin 5.9+20140118-1ubuntu1 amd64 terminal-related programs and man pages
ii ncurses-term 5.9+20140118-1ubuntu1 all additional terminal type definitions
But g++ tells me this when I try to make
bankacct.cpp:18:29: fatal error: ncurses.h: No such file or directory
compilation terminated.
Unfortunately, I've not got root access and I need to be able to compile on this machine. What are my options?
I've tried including <ncursesw/ncurses.h> based on suggestions from other users, but now g++ is giving me this error:
$ make bankacct
g++ -Wall -g -o bankacct bankacct.cpp -std=c++11 -lncurses
/usr/bin/ld: cannot find -lncurses
and if I try removing -lncurses it gives me this:
$ make bankacct
g++ -Wall -g -o bankacct bankacct.cpp -std=c++11
/tmp/cc8rPQfK.o: In function `main':
bankacct.cpp:23: undefined reference to `initscr'
Now I've tried linking the libraries. Here's what I did:
$ locate libncurse
/lib/x86_64-linux-gnu/libncurses.so.5
/lib/x86_64-linux-gnu/libncurses.so.5.9
/lib/x86_64-linux-gnu/libncursesw.so.5
/lib/x86_64-linux-gnu/libncursesw.so.5.9
/usr/lib/x86_64-linux-gnu/libncurses++w.a
/usr/lib/x86_64-linux-gnu/libncursesw.a
/usr/lib/x86_64-linux-gnu/libncursesw.so
/usr/share/doc/libncurses5
/usr/share/doc/libncursesw5
/usr/share/doc/libncursesw5-dev
/var/lib/dpkg/info/libncurses5:amd64.list
/var/lib/dpkg/info/libncurses5:amd64.md5sums
/var/lib/dpkg/info/libncurses5:amd64.postinst
/var/lib/dpkg/info/libncurses5:amd64.postrm
/var/lib/dpkg/info/libncurses5:amd64.shlibs
/var/lib/dpkg/info/libncurses5:amd64.symbols
/var/lib/dpkg/info/libncursesw5-dev:amd64.list
/var/lib/dpkg/info/libncursesw5-dev:amd64.md5sums
/var/lib/dpkg/info/libncursesw5-dev:amd64.postinst
/var/lib/dpkg/info/libncursesw5:amd64.list
/var/lib/dpkg/info/libncursesw5:amd64.md5sums
/var/lib/dpkg/info/libncursesw5:amd64.postinst
/var/lib/dpkg/info/libncursesw5:amd64.postrm
/var/lib/dpkg/info/libncursesw5:amd64.shlibs
/var/lib/dpkg/info/libncursesw5:amd64.symbols
So then I tried two variations of my makefile:
g++ -Wall -g -L/usr/lib/x86_64-linux-gnu/ -o $* $*.cpp -std=c++11 -lncurses
and
g++ -Wall -g -L/lib/x86_64-linux-gnu/ -o $* $*.cpp -std=c++11 -lncurses
which still gave me the errors undefined reference to 'initscr' (without -lncurses) or /usr/bin/ld: cannot find -lncurses (with it)
-lncurses
tells the linker to look for a library called "ncurses.". You clearly indicate that's not what your library is called:
/usr/lib/x86_64-linux-gnu/libncursesw.a
You need
-lncursesw
You don't need to modify the source code to specify <ncursesw/ncurses.h> you can simply add
-I/usr/include/ncursesw

Linking libraries in GCC

there are some files that I am trying to compile in ubuntu using makefile.
I have added the following lines in my makefile after several searches on web.
run: hellocode.cpp
g++ -c hellocode.cpp -lssl -lcrypto
Still while compiling it creates the object files and then throws this error:
undefined reference to 'SSL_write'....
on the contrary if remove the '-c' and use it like this
run: hellocode.cpp
g++ hellocode.cpp -lssl -lcrypto
Then I dont see the previous errors of linking but it shows different errors not related to openssl linking but related to other files in the code. I have already browsed through many questions on this forum related to this none seem to have helped me in this.
Kindly tell me whether my makefile is wrong or is there some problem with my machine that its not able to link to my library.
Here's a simple Makefile that you could adopt. Note that compilation and linking are 2 steps. If needed you can use -I for additional include paths and -L for additional link paths.
.PHONY : all
all : hellocode
hellocode : hellocode.o
g++ -o hellocode hellocode.o -lssl -lcrypto
hellocode.o : hellocode.cpp
g++ -c hellocode.cpp -o hellocode.o
Here are some basics of makefiles if it helps.
library linking should be done at final stage - linking :)
-c means "compile only" - it just builds .o object file, without any reference resolution (so -lXXX is just ignored there).
-lXXX options should be added to last call to gcc (without -c) which produces executable, where all .o files are gathered to link together with libraries to resolve all references.

C++: linker cannot find -lcrypto, but the library is in the path

I am compiling a C++ application using GNU g++. The project takes advantage of OpenSSL libraries.
Background
On my machine (a 64 bit CentOS quad core) I compile and link my files.
g++ -g -c -L/usr/local/lib/ -L/usr/lib64/
-I/usr/local/include/ -I/usr/local/ssl/include/
-lcrypto mysrc1.cpp mysrc2.cpp mysrc3.cpp
g++ -L/usr/local/lib/ -L/usr/lib64/ -lcrypto
*.o -o ./myapp.out
My application uses function MD5 which is contained in libcrypto.so. As you can see I specify to g++ the dirs where to search using the -L, -I options and which libraries to look for with the -l<lib-name> option. There are some trivial paths like /usr/local/lib which can be omitted of course, but I specified them because the makefile is parametric.
The problem
My problem is that I can successfully compile my stuff (first command), but linking fails (second command):
/usr/bin/ld: cannot find -lcrypto
collect2: ld returned 1 exit status
make: * [cppsims_par] Error 1
But I did check folders and everything... libcrypto.so is inside /usr/lib64/. What is going on?
It may help if you try strace to find why it failed the file lookup
strace -f -e trace=file g++ -L/usr/local/lib/ -L/usr/lib64/ -lcrypto
*.o -o ./myapp.out
I did find the problem and it is related to this question: ld cannot find an existing library
Actually I had no symlink libcrypto.so and the compiler was not able to find the library...
I had related issue, and resolved it after inspecting the trace.
I had
-L<my/path/to/lib> -llib_some_library
when it should have been
-L<my/path/to/lib> -lsome_library

How to link boost libraries properly in Linux

I've been trying to go through Boost tutorials but I got stuck at linking the filesystem library.
I have Ubuntu 12.10. Installation wasn't that hard
sudo apt-get install libboost-all-dev
This put all headers in /usr/local/include and compiled sources in /usr/lib/
[--headers]
[--binaries]
I wrote this program [--program]. When I tried to compiled it
g++ -g tut1.cpp -o tut1 -lboost_system -lboost_filesystem
got this errors: [--errors].
After a little search on http://www.boost.org/doc/libs/1_53_0/more/getting_started/unix-variants.html
I tried this:
g++ -g -I /usr/local/include/boost/ tut1.cpp -o tut1 -L /usr/lib/libboost_filesystem.a -lboost_system -lboost_filesystem
but didn't have luck. I had the same errors.
Since I cannot put more than 2 links in the post, here are all links
http://pastebin.com/DakVFn12
I found the answer myself here:
http://www.richelbilderbeek.nl/CppLinkErrorUndefinedReferenceToBoostFilesystemDetailGet_current_path_api.htm
Looks like binaries weren't in /usr/lib but in /usr/local/lib.
So the correct command for compilation would be:
g++ -g tut1.cpp -o tut1 -L/usr/local/lib/ -lboost_filesystem
#Yuushi, that was 1 problem.
The -L command should be the base path where the libraries are contained, not the path to a specific library. Try with -L /usr/lib/ instead.

CUDA: Creating object with G++ linker and cuda object files

I compiled my normal cpp files to .o, and my cuda .cu files to .co
I want to link these so I can call the cuda stuff from my normal C++ file
Here is my linker command that Make is running:
g++ -I ../readers/ -I../writers -I../common/ -I /home/dcole/software/xerces-c-3.1.1/src -I /home/dcole/NVIDIA_GPU_Computing_SDK/C/common/inc/ -I /usr/local/cuda/include -O3 -fPIC -fopenmp -DFIX_PAULI -DFIX_YAMA -DUSING_CUDA -o YamaguchiGPU YamaguchiMain.o YamaguchiDecomp.o cuYamaguchi.co -L/usr/lib64/ ../../lib/IDT.a ../../lib/Linux/libxerces-c.a ../../lib/Linux/libfftw3f.a -lcurl -lidn -ldl -lssl -lm -lpthread -lcuda -L/usr/local/cuda/lib64/libcudart.so
So I am definitly linking cuda, and cudart, but yet I get this:
cuYamaguchi.co: In function `__sti____cudaRegisterAll_46_tmpxft_00003190_00000000_4_cuYamaguchi_cpp1_ii_init_gpu()':
tmpxft_00003190_00000000-1_cuYamaguchi.cudafe1.cpp:(.text+0x1b4): undefined reference to `__cudaRegisterFatBinary'
tmpxft_00003190_00000000-1_cuYamaguchi.cudafe1.cpp:(.text+0x20f): undefined reference to `__cudaRegisterFunction'
The Cuda file is being linked without problems but it looks like you might have forgotten to define some necessary function (like cudaRegisterFatBinary).
Upgrading to gcc 4.7.0 or higher should fix this horrid linker issue.
I was using an absolute search path in the linker to _libcudart.so_. I changed the -L to point to just the folder, then added -libcudart so it would search the folder for that lib.