I have a simple MAKE fie that executes OK on Linux and Windows, and compiles a file containing C++-style comments (i.e., // to newline) without issue.

On zOS, the same file barfs if it encounters C++ comments, as follows:

cc -DOECS -D_OE_SOCKETS -D__UU -DPREFIX=\\"/usr\\" -o vfiled.o -c vfiled.c

ERROR CCN3046 ./vfiled.c:27    Syntax error.
ERROR CCN3334 ./vfiled.c:27    Identifier s4 has already been defined on line 26 of "./vfiled.c".
ERROR CCN3046 ./vfiled.c:57    Syntax error.
ERROR CCN3022 ./vfiled.c:57    "sin_family" is not a member of "struct sockaddr".
ERROR CCN3046 ./vfiled.c:59    Syntax error.
ERROR CCN3022 ./vfiled.c:59    "sin_port" is not a member of "struct sockaddr".
ERROR CCN3046 ./vfiled.c:62    Syntax error.
ERROR CCN3022 ./vfiled.c:62    "sa_port" is not a member of "struct sockaddr".
ERROR CCN3046 ./vfiled.c:73    Syntax error.

All of the indicated lines above contain commented-out lines; e.g.:

line 26:     struct sockaddr *sa, s4;
line 27: //  struct sockaddr_in s4;

OK - so I added the following to the configure script CFLAGS variable: -qcpluscmt

The compiler replies:

cc -DOECS -D_OE_SOCKETS -D__UU -qcpluscmt -DPREFIX=\\"/usr\\" -o vfiled.o -c vfiled.c
FSUM3007 -l is not a valid option.

How do I tell the compiler to allow C++ comments?