[Bug-readline] readline -vs- -Wstrict-prototypes

[Tom Tromey]

We would like to use -Wstrict-prototypes for GDB.  However, readline
headers prevent this.

There are a couple problems I am aware of.


First, rltypedefs.h defines some prototype-less typedefs by default,
e.g.:

typedef int Function ();

We would work around this with `#define _FUNCTION_DEF', but I think it
would be better for readline to just drop this code.  C90 has been
widely deployed for a long time now; other GNU projects have
unconditionally dropped K&R compatibility quite a while ago.

If the workaround stays, I think the symbol should have an `RL' prefix.


Second, rl_message is declared without a prototype in some cases:

#if defined (USE_VARARGS) && defined (PREFER_STDARG)
extern int rl_message (const char *, ...)  __attribute__((__format__ (printf, 
1, 2)));
#else
extern int rl_message ();
#endif

However, I think USE_VARARGS is only defined in config.h, which is not
installed.

I think best practice for a library is to make an installable config.h
where all symbols are given the library prefix.  That way it can be
included in other projects without danger of symbol clashes.

Tom