Automake includes full support for C++.
Any package including C++ code must define the output variable CXX in configure.in; the simplest way to do this is to use the AC_PROG_CXX macro ().
A few additional variables are defined when a C++ source file is seen:
The name of the C++ compiler.
Any flags to pass to the C++ compiler.
The maintainer's variant of CXXFLAGS.
The command used to actually compile a C++ source file. The file name is appended to form the complete command line.
The command used to actually link a C++ program.