I use the GCC compiler.
When compiling a program one often needs to link in a huge number of library files like .so extension to get the program to work.
Now for the C program that I am writing all the library files I need to link are inside a folder.
What should I write in my GNU Makefile if I wish to link ALL the library files in that folder to my program/executable.
target.exe: target.o
gcc -o target.exe target.o libdir/*.so
Related
I am working on a fortran project with many files and libraries. To organize information I created within the working directory three subfolders, call them /code, /obj and /bin.
How can I write a shell script so that I can invoke
gfortran -c $(code)/file1.f90 $(code)/file2.f90 $(code)/file3.f90
gfortran -c -J/$(obj) $(bin)/binary $(obj)/file1.o $(obj)/file2.o $(obj)/file3.o
I know it is a very stupid question but I am not familiar with shell scripting or 'make'. Thank you very much in advance
I have installed the cds library with command ./build.sh -b 64 -z '-std=c++0x' -l '-L /usr/lib/x86_64-linux-gnu' --with-boost /usr/include/boost --amd64-use-128bit at build folder.
After I tried to compile the example init.cpp of src folder, I typed this in terminal: g++ init.cpp -o init, and terminal showed: fatal error: cds/init.h: No such file or directory.
What should I do for compilation command in this case?
Thanks.
For general troubleshooting in cases like this, i would recommend finding where on the system the file got installed (if your build.sh actually installed the file). You would be able to find the missing header file using
find / -path '*/cds/init.h' 2>/dev/null
Then you need to supply two parameters to g++:
First one gets the compiler to know about the include files from the install directory
-I path_to_folder_one_step_above_cds_folder
Second one gets the linker to know about the librarys location. If the library file is called libcds.so, you can find it by running
find / -name libcds.so 2>/dev/null
So for linking, you supply the flag
-L path_to_folder_one_step_above_libcds.so
In your case you might not need the -L flag, since most of your library supposedly is header only.
UPDATE: the build.sh script is printing out important information at the top, starting with "Building with the following options:". The important bits will be "Compile options:" and "Link options:". Those should be enough to solve your specific option.
UPDATE2: build.sh also exports some flags which might include more options. You can print them out directly after running build.sh by running
echo LDFLAGS=$LDFLAGS
echo CFLAGS=$CFLAGS
echo CXXFLAGS=$CXXFLAGS
you are likely to need to pass all these options to g++ when compiling and linking against that library. LDFLAGS are specific to the linker only. Both the other ones are needed for compiling c++ files.
I have a couple of libraries built by the NDK for which I am trying to view the exported symbols, the available function names to be precise. One is a .so file and the other a .a file. I was helped in this question (How to obtain readelf and objdump binaries for OS X?) to find the utilities that I think I need. They are specific to the NDK installation. I am on OS X fyi.
In my NDK installation I found nm and objdump in prebuilt/darwin-x86_64/arm-linux-androideabi/bin. Their file type is "Alias". When I ran nm -g libMylib.so nothing happened -- at all. When I ran objdump -TC libMylib.so I got: "objdump: command not found". Then I found the arm-linux-androideabi-nm and arm-linux-androideabi-objdump files (file type listed as "Unix Executable File" in Finder) in the prebuilt/darwin-x86_64/bin dir. The attempt to use both of them resulted in "command not found". In all these attempts I placed libMylib.so right in the very folder with the utility I'm trying to run.
I think this is basically a general issue about how to call binaries in unix; even if you are in the same directory when you run nm -g libMylib.so, since . normally isn't part of your $PATH. To run the right one, do ./nm -g libMylib.so, or without using cd to enter this directory first, just do path/to/your/NDK/android-ndk-r10e/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64/bin/arm-linux-androideabi-nm -g libMylib.so, or add this directory to your path first:
export PATH=path/to/your/NDK/android-ndk-r10e/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64/bin:$PATH
arm-linux-androideabi-nm -g libMylib.so
(It's preferrable to add this directory to the path instead of the arm-linux-androideabi directory, since it is clear which tool you want to invoke when you call when you do arm-linux-androideabi-nm, while if you add the other directory and call nm, it is up to the order of the directories in $PATH.)
See e.g. Why do you need ./ (dot-slash) before script name to run it in bash? for more explanations about $PATH.
I can run compile in OSX terminal using g++ -Wall -c pa1.cpp -o pa1. Which creates pa1, so I know my compilation works in terminal but I am having issues with execution. I have tried ./pa1 , ./a.out, pa1 and few others. I believe the issue is with Xcode, yet the fact that my code will compile in terminal and creates an executable makes me unsure. Thought, I would ask here for suggestions before reinstalling Xcode.
Use g++ pa1.cpp -o pa1 and then you'll be able to run your new executable as ./pa1. This require that your whole program is in pa1.cpp. If it is spread in multiple files, you'll have to list all of them on the command-line.
As said in the comments, the -c option means compile, ie. Create an object file that can be passed to the linker to build an executable. If you don't use this option, g++ will first compile any source file, then invoke the linker on all the object files to create an executable named a.out by default (name comes from historical reason).
You can see that the output of your command was not an executable binary but an intermediate object file by using the file util.
I have a folder with 354 .f90 modules (and the main file). In the readme this is suggested:
The best approach is to unzip the archive source.zip extracting all
354 program files into a directory of your choice. Then you can
compile with the command
gfortran *.f90 -o app.exe
I'm on Mac so i installed gfortran but doing the command written above doesn't work:
gfortran: *.f90: No such file or directory
So I suppose that a bash script is needed (or at least a makefile).
I'm not used to doing this so what should I do? Does there exist some automatic makefile generator?
It was just a stupidity issue. The extension of the files was .F90 and not .f90. With:
gfortran -o app *.F90
it worked.