I am trying to statically link SDL2 on Linux, with the goal of creating a binary that doesn't require any libraries to be required on the system. I understand this will require statically linking more than just SDL2, such as SDL2's dependencies and things like libc, so help on that front would be appreciated as well. But right now I can't get SDL2 to statically link at all.
I am using GCC, and SDL 2.0.16 that I compiled and installed myself with the default configuration, which includes static libraries. I already had SDL2 installed through my package manager, so my installation went to /usr/local/include/SDL2 and /usr/local/lib.
Running /usr/local/bin/sdl2-config --cflags --static-libs gives:
-I/usr/local/include/SDL2 -D_REENTRANT
-L/usr/local/lib -lSDL2 -lm -ldl -lpthread -lrt
No amount of messing around with these flags and -static have been able to produce a binary that doesn't dynamically link to SDL2. How can I do it?
Other flags I am using for other reasons are -std=c89 -Wall -Wno-unknown-pragmas -DNDEBUG -Os -g0 -s
Being able to cross compile and do this would be great, but I understand that's a lot more complex. I've been trying to compile with zig cc as that would allow cross-compilation later, but couldn't get it to work. I was able to get a build that didn't dynamically link to SDL2, but it would segfault.
In response to comments:
Running pkg-config --static --cflags --libs /usr/local/lib/pkgconfig/sdl2.pc gives:
-I/usr/local/include/SDL2 -D_REENTRANT -L/usr/local/lib -Wl,-rpath,/usr/local/lib -Wl,--enable-new-dtags -lSDL2 -lm -ldl -lpthread -lrt
Using that creates a dynamically-linked executable, so not what I want. If I add -static I get the error:
/usr/bin/ld: /usr/local/lib/libSDL2.a(SDL_dynapi.o): in function `get_sdlapi_entry':
/home/makeworld/Software/SDL2-2.0.16/src/dynapi/SDL_dynapi.c:237: warning: Using 'dlopen' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
Thanks to #HolyBlackCat and #keltar, I have been able to statically link SDL2.
I basically just used the output of pkg-config as provided in my question, but with the addition of -Wl,-Bstatic before -lSDL2 and -Wl,-Bdynamic after it. This statically links SDL2, but dynamically links all the other libraries.
The final command is:
gcc your_code.c -o your_executable -I/usr/local/include/SDL2 -D_REENTRANT \
-L/usr/local/lib -Wl,-rpath,/usr/local/lib -Wl,--enable-new-dtags \
-Wl,-Bstatic -lSDL2 -Wl,-Bdynamic -lm -ldl -lpthread -lrt
If your build of SDL2 is installed elsewhere, just change the /usr/local/include/SDL2 and /usr/local/lib part of the command to point to where the header files and .a files are respectively.
If I figure out how to cross-compile this setup, I will update this answer.
Related
I am unsure of what could be causing this as I have tried recompiling libcurl and using pre-compiled binaries.
My compiler command
x86_64-w64-mingw32-gcc -Wall -Lwin-lib -Iwin-lib -I./ -D WIN32 -D CURL_STATICLIB -mwindows ... -o win-export/SLM.exe -lm -lraylib -ltmx -lxml2 -lzlibstatic -lcurl
There aren't any compiler errors or linker errors. Is this a problem with my compiler? Or one the other libraries I am using?
Say I'm building and linking my application with clang
clang -I/usr/local/include -c -o app.o main.c
clang -L/usr/local/lib -o app app.o -lfoo
How do I know where libfoo.a or libfoo.dylib is located? Is there a verbose mode?
It's possible to search /usr/lib and /usr/local/lib manually, but doing so would be too tedious when you use many libraries.
If the linker is GNU ld, pass the linker option --trace, e.g.
clang -L/usr/local/lib -o app app.o -lfoo -Wl,--trace
If the linker is Darwin mach-o ld, pass the linker option -t, e.g.
clang -L/usr/local/lib -o app app.o -lfoo -Wl,-t
The linker will then report the path of each object file, archive(member) or
dynamic library that it loads.
I need a special compiler. This is my call from eclipse:
powerpc-stw-linux-uclibc-g++ -L/usr/lib/i386-linux-gnu -L/usr/lib -L/usr/libx32 -L/var/lib -o "Test" ./src/Test.o -lz -lcurl
But now Eclipse throw this:
/opt/powerpc-gcc-4.4.3-uclib/bin/../lib/gcc/powerpc-stw-linux-uclibc/4.4.3/../../../../powerpc-stw-linux-uclibc/bin/ld: skipping incompatible /usr/lib/i386-linux-gnu/libcurl.so when searching for -lcurl
/opt/powerpc-gcc-4.4.3-uclib/bin/../lib/gcc/powerpc-stw-linux-uclibc/4.4.3/../../../../powerpc-stw-linux-uclibc/bin/ld: skipping incompatible /usr/lib/i386-linux-gnu/libcurl.a when searching for -lcurl
/opt/powerpc-gcc-4.4.3-uclib/bin/../lib/gcc/powerpc-stw-linux-uclibc/4.4.3/../../../../powerpc-stw-linux-uclibc/bin/ld: cannot find -lcurl
I tried to compile under Ubuntu 14.04 x86. libcurl should be installed
$ curl-config --libs
-L/usr/lib/i386-linux-gnu -lcurl
Obviously, you are building for PowerPC, but linking with the lib for i386.
You need to download/build libcurl for PowerPC, and provide the correct path to it.
In other words, don't mix two different architectures.
Compiling .c files to a single LLVM IR and link multiple libraries during the compilation.
An example here with gcc:
gcc -c -Wall -g3 -DVERSION=\"1.1.2\" ssl_proxy.c -o ssl_proxy.o
gcc -o ssl_proxy ssl_proxy.o -lssl -lcrypto
Now, I want to compile the ssl_proxy.c to ssl_proxy.ll, simply using llvm-gcc -S -emit-llvm won't work as it will not let me link -lssl -lcrypto libraries.
Through this example I hope people can explain a bit more details about compilation with llvm-gcc (not clang), so that all visitors can learn from it and know how to compile complex multiple sources into one LLVM IR.
Compiling source files into LLVM IR does not perform linking, so it does not require any libraries - it just needs the headers.
I am running Ubuntu 12.04 and I'm currently working on a project involving C, OpenGL, a teapot and input methods.
The problem started when I decided to have arrow keys as input. I checked to see the key codes for arrow keys but all of the arrows return 0. I looked up how to get this to work and I found conio.h. Unfortunately, it is an old DOS header that is not available for Linux. Then I found a substitute called ncurses.
After installing the necessary libraries, by following the build instructions closely, I #included curses.h in my main.c source. When I first tried to compile using gcc, I got the following errors:
main.o:main.c:function _Key: error: undefined reference to 'stdscr'
main.o:main.c:function _Key: error: undefined reference to 'wgetch'
main.o:main.c:function _Key: error: undefined reference to 'stdscr'
main.o:main.c:function _Key: error: undefined reference to 'wgetch'
I found a fix by adding -lncurses to the makefile like so:
SOURCES=main.c
main: main.o
gcc -lm -lGL -lGLU -lglut -lncurses main.o -o main
main.o: main.c
gcc -lm -lGL -lGLU -lglut -c main.c
But I was greeted by another error:
/usr/bin/ld: error: cannot find -lncurses
As well as the previous errors.
I have spent the last 2 days searching both the Ubuntu forums and StackOverFlow. Any help would be appreciated.
P.S. I don't know if this is important but when I try to run /usr/bin/ld I get this error:
ld: fatal error: no input files
For anyone with the same problem I had: I was missing the 32 bit libraries; I was compiling 32 bit on a 64 bit server which was missing the lib32ncurses5-dev package.
On Ubuntu I simply ran:
sudo apt-get install lib32ncurses5-dev
First off, you should put the libraries after the object file when linking. And not have them at all in the compilation of of the source file.
After that, if ncurses is not installed in a standard search folder you need to point out to the linker where it is, this is done with the -L command line option:
gcc main.o -o main -L/location/of/ncurses -lm -lGL -lGLU -lglut -lncurses
Try installing the ncurses-static package too, if you have only the ncurses-devel package installed in your Ubuntu OS.
If that solves your problem, plus if you add #Joachim's compiling instructions, you are off to a great start.
gcc main.o -o main -L/location/of/ncurses -lm -lGL -lGLU -lglut -lncurses
The linker can't find your shared library in it's search path. If you add the directory where your shared lib is to the LD_LIBRARY_PATH environment variable the linker should find it and be able to link against it. In that case you could omit the -L option to gcc:
gcc main.o -o main -lm -lGL -lGLU -lglut -lncurses
And it should compile fine.
EDIT:
Good to know that apt-get install libncurses5-dev fixes your problem.
FYI.
The LD_LIBRARY_PATH environment variable contains a colon separated list of paths that the linker uses to resolve library dependencies at run time. These paths will be given priority over the standard library paths /lib and /usr/lib. The standard paths will still be searched, but only after the list of paths in LD_LIBRARY_PATH has been exhausted.
The best way to use LD_LIBRARY_PATH is to set it on the command line or script immediately before executing the program. This way you can keep the new LD_LIBRARY_PATH isolated from the rest of your system i.e. local to the current running running instance of shell.
$ export LD_LIBRARY_PATH="/path/to/libncurses/library/directory/:$LD_LIBRARY_PATH"
$ gcc main.o -o main -lm -lGL -lGLU -lglut -lncurses