I'm trying to use std.net.curl on 32-bit Ubuntu Linux (11.10 Ocelot) using DMD 2.058.
When I build (dmd source.d) I get:
/usr/lib/gcc/i686-linux-gnu/4.6.1/../../../../lib/libphobos2.a(curl.o): In function `_D3std3net4curl4Curl19_sharedStaticCtor30FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticCtor30FZv+0x6): undefined reference to `curl_global_init'
/usr/lib/gcc/i686-linux-gnu/4.6.1/../../../../lib/libphobos2.a(curl.o): In function `_D3std3net4curl4Curl19_sharedStaticDtor31FZv':
std/net/curl.d:(.text._D3std3net4curl4Curl19_sharedStaticDtor31FZv+0x4): undefined reference to `curl_global_cleanup'
/usr/lib/gcc/i686-linux-gnu/4.6.1/../../../../lib/libphobos2.a(curl_12fd_140.o): In function `_D3std3net4curl4HTTP4Impl6__dtorMFZv':
std/net/curl.d:(.text._D3std3net4curl4HTTP4Impl6__dtorMFZv+0x12): undefined reference to `curl_slist_free_all'
/usr/lib/gcc/i686-linux-gnu/4.6.1/../../../../lib/libphobos2.a(curl_12fd_140.o): In function `_D3std3net4curl4HTTP3dupMFZS3std3net4curl4HTTP':
std/net/curl.d:(.text._D3std3net4curl4HTTP3dupMFZS3std3net4curl4HTTP+0x53): undefined reference to `curl_slist_append'
[snip]
I added -L-lcurl to my command line (full command: dmd source.d -L-lcurl) but I get the exact same result. I have libcurl4-openssl installed. I can build a simple C curl program on this computer without issue (gcc simple.c -lcurl). I'm not sure where to look from here to figure this out.
Update: Here is how the linker is invoked according to dmd -v:
gcc source.o -o source -m32 -lcurl -Xlinker -L/usr/lib -Xlinker -L/usr/lib64 -Xlinker --no-warn-search-mismatch -Xlinker --export-dynamic -lphobos2 -lpthread -lm -lrt
As you yourself discovered, the order of libraries is incorrect. A quote from "An Introduction to GCC": "A library which calls an external function defined in another library should appear before the library containing the function." In your case libphobos calls external library's (libcurl) function(s), so I guess libphobos should go before libcurl.
The book is available online. Chapter related to the OT is here: http://www.network-theory.co.uk/docs/gccintro/gccintro_18.html
The DMD compiler is clearly broken in this respect. I published a patch to fix it (maybe not the best) but the maintainer of the compiler is not convinced this needs to be fixed at all so there is no much discussion about it.
https://github.com/D-Programming-Language/dmd/pull/497
http://d.puremagic.com/issues/show_bug.cgi?id=7044
Seemingly the simplest way to fix the phobos2/curl linker order problem, as mentioned elsewhere in this thread:
dmd source.d -L-lphobos2 -L-lcurl
Works like a charm for me.
I figured out if I obtain the linker command through -v and reorder it so the -lcurl is at the end it links without issue.
gcc source.o -o source -m32 -Xlinker -L/usr/lib -Xlinker -L/usr/lib64 -Xlinker --no-warn-search-mismatch -Xlinker --export-dynamic -lphobos2 -lpthread -lm -lrt -lcurl
I'm still curious if there is a way to fix this without manually running the linker.
Related
I did not get response from Qualcomm forum so I decided to post here. When I was trying to run examples of Halide for Hexagon by running make run as written in the document. Then I got the following issue. The -lc++abi is missing.
clang++ -std=c++11 -I /opt/qcom/Hexagon_SDK/4.3.0.0/tools/HALIDE_Tools/2.3.03/Halide/include -stdlib=libc++ -O3 -g -fno-rtti -rdynamic conv3x3_generator.cpp /opt/qcom/Hexagon_SDK/4.3.0.0/tools/HALIDE_Tools/2.3.03/Halide/lib/libHalide.a /opt/qcom/Hexagon_SDK/4.3.0.0/tools/HALIDE_Tools/2.3.03/Halide/tools/GenGen.cpp -o /opt/qcom/Hexagon_SDK/4.3.0.0/tools/HALIDE_Tools/2.3.03/Halide/Examples/build/offload/hexagon_benchmarks/bin/conv3x3.generator -lz -lrt -ldl -lpthread -lm
/usr/bin/ld: cannot find -lc++abi
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I checked the /usr/lib and find. So it should be there?
./x86_64-linux-gnu/libc++abi.so.1.0
./x86_64-linux-gnu/libc++abi.so.1
./llvm-10/lib/libc++abi.so.1.0
./llvm-10/lib/libc++abi.so.1
Did I miss anything or make anything stupid? Thanks!
ld is your system's host linker -- that's GNU BFD ld. clang++ must be in your PATH but it's the host clang++ and not the hexagon-clang++ that would be with Halide/Hexagon tools.
I contacted the person from Qualcomm. I am not supposed to use either /usr/bin/clang++ nor hexagon-clang++. I downloaded clang+llvm-7.0.1-x86_64-linux-gnu-ubuntu-18.04.tar.xz from https://releases.llvm.org/7.0.1/. You should use clang++ under the bin folder after you extract it. Now it works for me.
So i am trying to compile a simple GLFW window app, and i ran into a linker problem.
gcc -o bin/mtx_gui `pkg-config --libs glfw3 glew` src/main.c
i use this command to compile single main. pkg-config expands into -L/usr/local/lib -lglfw3 -lGLEW -lGLU -lGL which should compile everything. i checked all libs are where they suposed to be. no idea why it is not linking it
main.c:(.text.startup+0x2): undefined reference to `glfwInit'
First, as pointed by G.M in the comment, main.c goes before all libs. second and the most important.
-lglfw3 -lrt -lm -ldl -lpthread -lGL
Libpthread must be also linked, and if you plan on using opengl link Libgl as shown above.
I am compiling a C++ application on Ubuntu 18.04.
The linker is unable to pickup the required functions from the library or it is not locating the right library
I have libcurl.so located at /usr/local/lib
nm -D lists all the functions I need with T prefix. Yet when I compile as follows
g++ -std=c++17 -lcurl tz.o main.o
I get
/usr/bin/ld: tz.o: in function 'date::curl_global()':
tz.cpp:(.text+0x9aef): undefined reference to 'curl_global_init'
I tried installing openssl-dev. No joy. So I uninstalled it.
try
g++ -std=c++17 tz.o main.o -lcurl
instead... g++ is shit in some ways, like argument ordering. (all i did was to make -lcurl the last argument instead of argument #3)
I am rather new to Linux (using Ubuntu 14.04 LTS 64bit), coming from Windows, and am attempting to port over an existing CUDA project of mine.
When linking via
/usr/local/cuda/bin/nvcc -arch=compute_30 -code=sm_30,compute_30 -o Main.o Display.o FileUtil.o Timer.o NeuralNetwork.o -L/usr/lib -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu -L/usr/local/cuda/lib64 -lGLEW -lglfw3 -lGL -lGLU -lcuda -lcudart
I encounter the following error:
/usr/bin/ld: /usr/local/lib/libglfw3.a(x11_clipboard.c.o): undefined reference to symbol 'XConvertSelection'
//usr/lib/x86_64-linux-gnu/libX11.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make: *** [CUDANN] Error 1
The answer seems closely related to the solutions in this post (Strange linking error: DSO missing from command line), though given my inexperience with Linux I was unable to adapt them to my own problem.
Any ideas on what the problem could be?
Here is the full output during compilation: https://gist.github.com/wbolden/857eddd11e4dcb915c02
And here is my attempt at a Makefile:
https://gist.github.com/wbolden/135033daae04ed0d8cf3
Hopefully this will be of help to those, like me, who are new to Linux and don't find anything related to Linux to be particularly obvious.
As noted by talonmies, I am not able to link indirectly and as such need to specify any additional libraries required by the libraries I am using. That is to say, if I link library A, which requires libraries B and C, I need to link all three libraries for the program to link correctly.
To find what other libraries were needed I used the pkg-config command, for which I found a guide here. Running pkg-config --print-requires --print-requires-private glfw3 gave the following output, which is the list of packages required by glfw3.
x11
xrandr
xi
xxf86vm
gl
I was then able to find what libraries I needed to include by running pkg-config --libs, followed by the name of the library. For example, pkg-config --libs x11 yielded -lX11.
Note: you can pass multiple items to pkg-config as input, so running
pkg-config --libs $(pkg-config --print-requires --print-requires-private glfw3)
will print out all the additional libraries you need to link (-lX11 -lXrandr -lXi -lXxf86vm -lGL).
My program now links successfully, I hope this helpful to anyone with a similar problem.
Your linker need X11 library,You need to specify -lX11 to linker
Try
/usr/local/cuda/bin/nvcc -arch=compute_30 -code=sm_30,compute_30 -o Main.o Display.o FileUtil.o Timer.o NeuralNetwork.o -L/usr/lib -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu -L/usr/local/cuda/lib64 -lGLEW -lglfw3 -lGL -lGLU -lcuda -lcudart -lX11
Try to add -pthread at the end of the library list (command line) in the Makefile.
It worked for me.
Use the following commands to fix the issue:
FLAGS=-lX11 ./configure --prefix=/usr --disable-static
make
make install
I'm trying to compile a simple test program using static OpenCV libraries that have been compiled using an ARM compiler. But when I try to compile it with the command
$arm-linux-gnueabihf-g++ `pkg-config --static opencv` -I/usr/local/include -L<path to static libary> -lopencv_imgproc -lopencv_core ARMtest2.cpp -o ARMtest2
This gives
/tmp/ccxNeUbK.o: In function main':
ARMtest2.cpp:(.text+0x8a): undefined reference tocv::Mat::ones(int, int, int)'
/tmp/ccxNeUbK.o: In function cv::Mat::~Mat()':
ARMtest2.cpp:(.text._ZN2cv3MatD2Ev[_ZN2cv3MatD5Ev]+0x20): undefined reference tocv::fastFree(void*)'
/tmp/ccxNeUbK.o: In function cv::Mat::release()':
ARMtest2.cpp:(.text._ZN2cv3Mat7releaseEv[_ZN2cv3Mat7releaseEv]+0x30): undefined reference tocv::Mat::deallocate()'
collect2: error: ld returned 1 exit status
The code itself is just some simple test code that prints a Mat type variable.
I compiled the static OpenCV library with cmake-gui. I selected UNIX Makefile and then selected 'specify options for cross-compiling' where I gave the path to the ARM (arm-linux-gnueabihf) gcc and g++ compiler. Then I unticked BUILD_SHARED_LIB so it compiled static libraries. It seemed to compile fine without errors. After that I did make & sudo make install.
I also tried it with shared libraries and that worked fine on the ARM board (once I copied the libraries to the board and exported the library path).
The static .a files landed nicely in the build folder. Apparently it can also find it when I -L link to it. I have tried reversing the order of the libraries, but to no avail.
So I'm a bit at a loss what is going wrong.
I solved it. Using the normal --static pkg-config command to compile with OpenCV libraries;
`pkg-config --libs --static opencv`
Of course I installed the static libraries also to the folder /usr/local/lib where libraries get installed first. But still i don't know what I missed in the command line I tried to use. I had a look in the config file /usr/local/lib/pkgconfig/opencv.pc
Here is whats in it:
# Package Information for pkg-config
prefix=/usr/local
exec_prefix=${prefix}
libdir=
includedir_old=${prefix}/include/opencv
includedir_new=${prefix}/include
Name: OpenCV
Description: Open Source Computer Vision Library
Version: 2.4.9
Libs: ${exec_prefix}/lib/libopencv_calib3d.so ${exec_prefix}/lib/libopencv_contrib.so ${exec_prefix}/lib/libopencv_core.so ${exec_prefix}/lib/libopencv_features2d.so ${exec_prefix}/lib/libopencv_flann.so ${exec_prefix}/lib/libopencv_gpu.so ${exec_prefix}/lib/libopencv_highgui.so ${exec_prefix}/lib/libopencv_imgproc.so ${exec_prefix}/lib/libopencv_legacy.so ${exec_prefix}/lib/libopencv_ml.so ${exec_prefix}/lib/libopencv_nonfree.so ${exec_prefix}/lib/libopencv_objdetect.so ${exec_prefix}/lib/libopencv_ocl.so ${exec_prefix}/lib/libopencv_photo.so ${exec_prefix}/lib/libopencv_stitching.so ${exec_prefix}/lib/libopencv_superres.so ${exec_prefix}/lib/libopencv_ts.a ${exec_prefix}/lib/libopencv_video.so ${exec_prefix}/lib/libopencv_videostab.so -lrt -lpthread -lm -ldl
Cflags: -I${includedir_old} -I${includedir_new}
I believe this is what is being called with the pkg-config <--something_or_other> opencv line.
And saw some other things that probably get linked when compiling -lrt -lpthread -lm -ldl Not really sure though as I tried it ina normal command line and I apparently still missed somethings.
But it worked, so didn't really bother too much with it much further :)
In your command:
*$arm-linux-gnueabihf-g++ `pkg-config --static opencv` -I/usr/local/include -L<path to static libary> -lopencv_imgproc -lopencv_core ARMtest2.cpp -o ARMtest2*
The cflags was missing.
Try with:
$arm-linux-gnueabihf-g++ `pkg-config --cflags --static opencv` -I/usr/local/include -L<path to static cross-compiled libary> -lopencv_imgproc -lopencv_core ARMtest2.cpp -o ARMtest2
Assuming here that your cross-compiled headers are saved in /usr/local/include (as you specified).