|  |  16.4.2 Automake C++ support 
Automake provides support for compiling C++ programs.  In fact, it makes
it practically trivial: files listed in a SOURCESprimary may
include `.c++', `.cc', `.cpp', `.cxx' or `.C'
extensions and Automake will know to use the C++ compiler to build them. 
For a project containing C++ source code, it is necessary to invoke the
AC_PROG_CXXmacro in `configure.in' so that Automake knows
how to run the most suitable compiler.  Fortunately, when little details
like this happen to escape you,automakewill produce a
warning: 
 |  | $ automake
automake: Makefile.am: C++ source seen but CXX not defined in
automake: Makefile.am: `configure.in'
 | 
 
 |