[Bug-readline] Linking Shared libreadline with(out) TERMCAP_LIB

[Дилян Палаузов]

Hello,

when I do ./configure --with-curses the TERMCAP_LIB Makefile variable is 
filled with -lcurses, and when I do ./configure --without-curses, 
TERMCAP_LIB is -ltermcap .

In terms of support/shobj-conf, my system is "linux-gnu-gcc-unknown", so 
the case "linux*-*|gnu*-*|k*bsd*-gnu-*|freebsd*-gentoo" on line 127 is 
called.

My SHLIB_LIBS is empty, because only on cygwin* and mingw* TERMCAP_LIB 
is added to SHLIB_LIBS .

In shlib/Makefile lines 175-182 the same linker parameters are used to 
link with libhistory and libreadline .  To my understanding, libhistory 
does not need TERMCAP_LIB, as the latter does not contain symbols 
libhistory needs, but despite of this, on mingw and cygwin, 
shlib/libhistory is linked with $TERM_CAP.

On the other side, under Linux, shlib/libreadline is liked with:

$(CC) -shared -Wl,-soname,libreadline.so.6.3 -L/usr/lib -L/lib 
-Wl,-rpath,/usr/lib -Wl,-soname,libreadline.so.6 -o libreadline.so.6.3 
readline.so vi_mode.so funmap.so keymaps.so parens.so search.so rltty.so 
complete.so bind.so isearch.so display.so signals.so util.so kill.so 
undo.so macro.so input.so callback.so terminal.so text.so nls.so misc.so 
history.so histexpand.so histfile.so histsearch.so shell.so mbutil.so 
tilde.so colors.so parse-colors.so xmalloc.so xfree.so compat.so

-> without passing TERMCAP_LIB, which leads to undefined symbols:

nm shlib/libreadline.so.6.3 | grep " U " | grep -v GLIBC

                 U BC
                 U PC
                 U tgetent
                 U tgetflag
                 U tgetnum
                 U tgetstr
                 U tgoto
                 U tputs
                 U UP

(I intentionally don't use "nm -D" as this would delete the @GLIB marker 
and hence I cannot filter).

Is there any reason, why TERMCAP_LIB is passed to the static linker (in 
/Makefile, line 184), but not to the shared linker?

Please add to support/shobj-conf:

--- support/shobj-conf  2014-04-11 19:58:26.385241268 +0000
+++ support/shobj-conf.orig      2014-04-11 19:57:31.815241203 +0000
@@ -130,7 +130,6 @@

        SHLIB_XLDFLAGS='-Wl,-rpath,$(libdir) -Wl,-soname,`basename $@ 
$(SHLIB_MINOR)`'
        SHLIB_LIBVERSION='$(SHLIB_LIBSUFF).$(SHLIB_MAJOR)$(SHLIB_MINOR)'
-       SHLIB_LIBS='$(TERMCAP_LIB)'
        ;;

 freebsd2*)

Another approach is to have different shared linking parameters for 
libreadline and libhistory (with and without TERMCAP_LIB / -lcurses), by 
adding TERMCAP_LIB to the end of shlib/Makefile(.in) line 177.  But 
choosing this approach I see no reason to continue adding TERMCAP_LIB to 
SHLIB_LIBS on MinGW and Cygwin.

Kind regards
  Дилян