Re: Patch to build gdb-5.0 with readline-4.1

[Andrew Gaylard <andrew dot gaylard at za dot didata dot com>]

Eli Zaretskii wrote:
> 
> > Date: Sun, 28 May 2000 21:03:18 +0200
> > From: Andrew Gaylard <andrew.gaylard@bsw.co.za>
> >
> >  /* readline include files */
> > +/* This is needed to prevent readline-4.1 (re-)defining it.  */
> > +#define savestring
> >  #include <readline/readline.h>
> >  #include <readline/history.h>
> >
> >  #include <signal.h>
> >
> > -/* readline defines this.  */
> > +/* readline needed this.  */
> >  #undef savestring
> 
> What's the story behind this savestring gork?  Is it possible to take
> care of the problem in a cleaner way?

From what I can see, readline used to use this, but doesn't any more.
But its headers keep it around, presumably for backward-compatibility:

from readline.h:
#if !defined (savestring)
extern char *savestring __P((char *)); /* XXX backwards compatibility */
#endif

and from histlib.h:
#ifndef savestring
#  ifndef strcpy
extern char *strcpy ();
#  endif
#define savestring(x) strcpy (xmalloc (1 + strlen (x)), (x))
#endif

and from rldefs.h:
#ifndef savestring
extern char *xmalloc ();
#define savestring(x) strcpy (xmalloc (1 + strlen (x)), (x))
#endif

This definition clashes with the one in gdb/defs.h:
extern char *savestring (const char *, int);

So it seemed simpler to me to simply #define savestring 
before #include <readline/...> and #undef savestring
afterwards.  But there's probably a better way.  Hopefully
when readline-4.2 appears, this sort of stuff won't be
necessary any longer.

> >    rl_completer_quote_characters = gdb_completer_quote_characters;
> >    rl_readline_name = "gdb";
> > +  rl_terminal_name=getenv("TERM");
> 
> What does readline do with rl_terminal_name?  What if getenv returns a
> NULL pointer?  (Non-Unix ports of GDB are likely to have $TERM
> undefined.)

Realine uses the terminal name to parse ~/.inputrc (or $INPUTRC).
I use it to do terminal-specific things like this (from my .inputrc):

$if TERM=xterm

# Home, End, Ctrl-backspace, Ctrl-Delete, Ctrl-left, Ctrl-Right
"\e[1~": beginning-of-line
"\e[2~": yank
"\e[4~": end-of-line
"\e[H": beginning-of-line
"\e[F": end-of-line       
"\eOw": beginning-of-line
"\eOq": end-of-line       
"\C-?": delete-char
"\C-w": backward-kill-word
"\e[KC4~": backward-word
"\e[KC6~": forward-word

$endif

I've tested the line I added to gdb with:
 + TERM=xterm
 + TERM=        (that is "export TERM=")
 + TERM not set (that is, "unset TERM")
None of these gave any problems.

--
Andrew Gaylard
andrewg @ bsw . co . za