链接静态库与动态库的问题

Question

I've successfully developed a code using a dynamic library. Nowadays I need to move to a static library. So I've built the library with make as specified by the author but when I tried to build my program I've faced these messages:

/usr/bin/ld: /usr/local/lib/libfft3dmpi.a(remap3d_wrap.o): in function `remap3d_create':
/home/mirco/Scrivania/fftmpi-1Oct18/src/remap3d_wrap.cpp:36: undefined reference to `operator new(unsigned long)'
/usr/bin/ld: /usr/local/lib/libfft3dmpi.a(remap3d_wrap.o): in function `remap3d_create_fortran(int, void**)':
/home/mirco/Scrivania/fftmpi-1Oct18/src/remap3d_wrap.cpp:45: undefined reference to `operator new(unsigned long)'

And so on.. I've tried to specify, in the makefile, the full path of the library or to use -l(name of the library) but I still face the same messages

My makefile is

$(CC) -O3 -o exe channel_mpi.o initialization.o convol_trasp.o fft_support.o data_man.o dnsdata.o dnsdirect.o /home/mirco/Scrivania/fftmpi-1Oct18/src/libfft3dmpi.a -lm 

The compiler is h5pcc, which is mpicc wrapped with some flags to use HDF5 library.

Have I done mistakes??

Thanks for your help

Answer 1

operator new is a C++ thing. It seems you're building with C++ code and not C. The makefile variable $(CC) is the C compiler, $(CXX) is the C++ compiler.

So the solution is to switch the compiler you're using for linking.

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When linking the C++ frontend program (typically g++ on Linux systems) will automatically add the C++ standard library. It's this library that contains the default implementations of many C++ standard functions, like the functions needed for the C++ new operator.

It is possible to use the C frontend ( gcc ) as well, but then you have to explicitly link with the C++ library. For gcc that means you have to add -lstdc++ .