However, avpicture_get_size is defined. No, as the header (<libavcodec/avcodec.h>) just declares it. The definition is in the library itself. So you might like to add the linker option to link libavcodec when invoking gcc: -lavcodec Please also note that libraries need to be specified on the command line after the files needing them: gcc -I$HOME/ffmpeg/include … Read more
DSO here means Dynamic Shared Object; since the error message says it’s missing from the command line, I guess you have to add it to the command line. That is, try adding -lpthread to your command line.
You may find that you have to link with the math libraries on whatever system you’re using, something like: gcc -o myprog myprog.c -L/path/to/libs -lm ^^^ – this bit here. Including headers lets a compiler know about function declarations but it does not necessarily automatically link to the code required to perform that function. Failing … Read more
My recommendation is to start simple, and then complicate your project further. Let me try to explain how linking works in CMake. The idea is that you build modules in CMake, and link them together. Let’s ignore header files for now, as they can be all included in your source files. Say you have file1.cpp, … Read more
How are you doing the compiling and linking? You’ll need to specify both files, something like: gcc testpoint.c point.c …so that it knows to link the functions from both together. With the code as it’s written right now, however, you’ll then run into the opposite problem: multiple definitions of main. You’ll need/want to eliminate one … Read more
You have compiled your code with references to the correct math.h header file, but when you attempted to link it, you forgot the option to include the math library. As a result, you can compile your .o object files, but not build your executable. As Paul has already mentioned add “-lm” to link with the … Read more
You need to define _frequency in the .cpp file. i.e. LARGE_INTEGER WindowsTimer::_frequency;
The implementation of a non-specialized template must be visible to a translation unit that uses it. The compiler must be able to see the implementation in order to generate code for all specializations in your code. This can be achieved in two ways: 1) Move the implementation inside the header. 2) If you want to … Read more
You need to compile with the link flag -lm, like this: gcc fib.c -lm -o fibo This will tell gcc to link your code against the math lib. Just be sure to put the flag after the objects you want to link.
You should mention the library on the command line after the object files being compiled: gcc -Wstrict-prototypes -Wall -Wno-sign-compare -Wpointer-arith -Wdeclaration-after-statement -Wformat-security -Wswitch-enum -Wunused-parameter -Wstrict-aliasing -Wbad-function-cast -Wcast-align -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes -Wmissing-field-initializers -Wno-override-init \ -g -O2 -export-dynamic -o utilities/ovs-dpctl utilities/ovs-dpctl.o \ lib/libopenvswitch.a \ /home/jyyoo/src/dpdk/build/lib/librte_eal.a /home/jyyoo/src/dpdk/build/lib/libethdev.a /home/jyyoo/src/dpdk/build/lib/librte_cmdline.a /home/jyyoo/src/dpdk/build/lib/librte_hash.a /home/jyyoo/src/dpdk/build/lib/librte_lpm.a /home/jyyoo/src/dpdk/build/lib/librte_mbuf.a /home/jyyoo/src/dpdk/build/lib/librte_ring.a /home/jyyoo/src/dpdk/build/lib/librte_mempool.a /home/jyyoo/src/dpdk/build/lib/librte_malloc.a \ -lrt -lm -lpthread … Read more