I have found the code which links against of 'g2c' library. Why do I need it? Just would like to understand why it might be important and what it does in general.
Thanks!
g77
consists of several components:
A modified version of the
gcc
command, which also might be installed as the system'scc
command. (In many cases,cc
refers to the system's “native” C compiler, which might be a non-GNU compiler, or an older version ofgcc
considered more stable or that is used to build the operating system kernel.)The
g77
command itself, which also might be installed as the system'sf77
command.The
libg2c
run-time library. This library contains the machine code needed to support capabilities of the Fortran language that are not directly provided by the machine code generated by theg77
compilation phase.
libg2c
is just the unique nameg77
gives to its version oflibf2c
to distinguish it from any copy oflibf2c
installed fromf2c
(or versions ofg77
that builtlibf2c
under that same name) on the system.
You may think of it as, libg2c
is to g77
as libc
is to gcc
.
Note that as of the GCC 4.x series, g77
has been discontinued, replaced by gfortran, which produces programs that do not require an extra libg2c
runtime library.