gcc:linker input file unused because linking not done - linux

When I run a make file in Linux to compile C codes, I get the following error:
gcc -Wall -fPIC -DSOLARIS -DXP_UNIX -DMCC_HTTPD -D_REENTRANT -I/opt/profile/OraAlert_test/code/include -I/usr/netscape/server4/plugins/include -I../../pwutils -I../../database/src -I../../access/src -I/data/share/capscan/include -o getEnv.o -c ../src/
gcc: ../src/: linker input file unused because linking not done
I have tried searching for related questions in stackoverflow and tried the the solutions suggested. Still this could not be resolved.
Any suggestions?

You have a compilation command without a source file.
What is it supposed to compile?
The error is indeed misleading. It assumes you want to link with ../src/, but -c says no linkage is to be done.

Related

About linking to the built riscv64 libgcc.a

I am new to riscv GNU toolchain. When compiling a program, some errors occured.
A hidden symbol named **'__gtdf2'** in /XXX/bin/../lib/gcc/riscv64-unknown-elf/10.2.0/rv64imac/lp64/libgcc.a(gedf2.o) is referenced by DSO.
This is my compile command:
riscv64-unknown-elf-g++ test.cpp ./libXXX.so -o test.out -I XXX/include/path/ -march=rv64imac -mabi=lp64
I am wondering that my built libgcc.a is uncorrect or some other reasons cause that.
Thanks a lot.

Question about compiling sources code with HDF5 and mpi

When I am trying to compile the source code by 'make', the first steps that creating the '.o' files are running fine, and all '.o' files could be compiled normally. However, when compiling the executable file:
mpifort -fopenmp -O3 -o MyEXE sth.o main.o -L/usr/local/share/fftw-3.3.8/lib -lfftw3_mpi -lfftw3 -lm -L/usr/local/share/mpich-3.2/lib -lmpi -lz -L/usr/local/share/hdf5-1.8.18/lib -lhdf5_fortran -lhdf5hl_fortran -lhdf5_hl -lhdf5 -fPIC
it gots the following error:
/usr/bin/ld: /usr/local/share/hdf5-1.8.18/lib/libhdf5.a(H5PL.o): undefined reference to symbol 'dlclose##GLIBC_2.2.5'
//lib/x86_64-linux-gnu/libdl.so.2: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
How could I solve this problem? Some pages suggest that it is due to the '-ldl- flag when calling c++ compiler, but I couldn't find a way to make it suitable for my cases.
The pages were right. Your HDF5 library libhdf5.a uses the function dlclose, which is defined in the library libdl. To use it, you need to simply add -ldl at the end of your mpifort command line.

Compile static library using g++

I have 3 classes - I denote those by firstClass,secondClass,thirdClass.
My headers - firstClass.h, secondClass.h, thirdClass.h and sources firstClass.cpp, secondClass.cpp, thirdClass.cpp.
In class thirdClass I create instance of firstClass and two instance of secondClass.
In main.cpp I deamonize and create instance thirdClass.
I want to create static library of thirdclass and linking to main.cpp.
firstClass and thirdClass used the same library libm.a
I created library step by step as following:
g++ -c -I-/usr/include/ -I-/usr/lib/ -I-/home/projects/Learninig firstClass.cpp -lstdc++ -lm-o WsChannel.o -w -m32
g++ -c -I-/usr/include/ -I-/usr/lib/ --I-/home/projects/Learninig secondClass -lstdc++ -o secondClass.o -w -m32
g++ -c -I-/usr/include/ -I-/usr/lib/ --I-/home/projects/Learninig thirdClass.cpp -lstdc++ -lm -o thirdClass.o -w -m32
ar rcs libLearning.a firstClass.o secondClass.o thirdClass.o
g++ main.cpp -L. -lLearning -lm -o MnLearning.o -m32
Compiling was maked correctly without any errors, but when I execute program I have same error. I spent some hours on checking code, but I don't find bugs. So then maybe compiling was incorrect. I did this using some tutorial in web.
If whatever was unclearly I am ready to more explain my question.
Edit: My error:
segfault at 557400000045 ip 00005574bd509dcd sp 00007ffd9e887900 error 4 in MnLearning[5574bd4f2000+26000]
The error is surely inside your own source code. Avoid undefined behavior in it, and be scared of UB.
Your use of -I- is strange, and probably wrong. I recommend removing it (and also, at first, remove the -m32 flag if your computer and distribution is 64 bits; work first to have your program run correctly on your laptop, then port it later to 32 bits Linux by adding the -m32 flag). You might use preprocessor options like -H to be shown what files are included.
I recommend building your library and your program with some build automation tool, such as GNU make or ninja.
Configure your build to compile with all warnings and debug info, i.e. using g++ -Wall -Wextra -g with GCC. Improve your source code to get no warnings. Then use the gdb debugger to understand the behavior of your program (and library).
So then maybe compiling was incorrect.
No, the compiler is probably good, and you should trust it.
The bug is very likely to be in your own code.
My error: segfault at 557400000045 ip 00005574bd509dcd sp 00007ffd9e887900 error 4 in MnLearning[5574bd4f2000+26000]
Segmentation fault is a symptom of some error in your own code (e.g. some buffer overflow, some bad pointer dereference, etc; or other kind of UB).
You might also use valgrind.
I spent some hours on checking code, but I don't find bugs.
You did not spend enough time (some bugs may take you weeks of work to be found), and you forgot to use the debugger, a very handy tool to help you understand the behavior of your program and find bugs in it. Be aware that programming is difficult, and don't be discouraged.

Linking error: DSO missing from command line

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

glui /usr/bin/ld: cannot find -lXmu

I have downloaded the latest GLUI source code and now I am trying to compile it. When I do so, I get the following error:
g++ -O0 -Wall -pedantic -I./ -I./include -I/usr/X11R6/include -o bin/example1 example/example1.cpp -L./lib -lglui -L/usr/X11R6/lib/libXdmcp.a -lglut -lGLU -lGL -lXmu -lXext -lX11 -lXi -lm
/usr/bin/ld: cannot find -lXmu
collect2: ld returned 1 exit status
When I did a locate libXmu, I get the following output:
> %:~/src/GLUI/src$ locate libXmu
> /usr/lib/libXmu.so.6
> /usr/lib/libXmu.so.6.2.0
> /usr/lib/libXmuu.so.1
> /usr/lib/libXmuu.so.1.0.0
Do I get the error because I don't have a /usr/lib/libXmu.so? If this is the case, how can I make one? (I am not experienced with linking at all).
Thanks!
Linux distributions usually package the libraries needed for running programs separately from the files needed to build programs.
Look for packages named *-devel or *-dev.
I don't know which one you need in particular for this, but you can use apt-cache search to look for it.
The answer was actually one of the first ones here originally but the owner deleted it, it seems. I was able to solve the problem by creating a symbolic link to the latest version of the library (i.e. /usr/lib/libXmu.so.6) and compile the code successfully.
I had the same problem, if creating a symbolic link doesnt help,
try the following:
Print your $PATH ("echo $PATH"),
and check if the library file you need is in one of those directories.
Use "export PATH=/newly/added/path:$PATH" to add new directory to check.
Ive been including libevent, added "-levent" in the gcc command, and ld used file /usr/lib/libevent.so, so it looks like the "lib" prefix and extension are being added automatically by ld.
Keep it up.

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