Hi Simon, Ludo,
> > /bin/bash ../libtool --preserve-dup-deps --mode=link g++ -o
> > test-fcntl-h-c++ test-fcntl-h-c++.o libtests.a ../gl/libgnu.la libtests.a
> >
> > libtool: link: unable to infer tagged configuration
> > libtool: link: specify a tag with `--tag'
> > make[4]: *** [test-fcntl-h-c++] Error 1
> > make[4]: Leaving directory `/home/jas/src/libidn/gltests'
>
> For the record, it also breaks “make check” in libunistring with current
> Gnulib:
Thanks for mentioning this. In libunistring, it is easier to reproduce for me.
The problem is that this piece of libtool documentation (from libtool 2.2.6,
node 'Tags') is incorrect:
`libtool' tries to automatically infer which tag to use from the
compiler command being used to compile or link. If it can't infer a
tag, then it defaults to the configuration for the `C' language.
The tag can also be specified using `libtool''s `--tag=TAG' option
(*note Invoking libtool::). It is a good idea to do so in `Makefile'
rules, because that will allow users to substitute the compiler without
relying on `libtool' inference heuristics. When no tag is specified,
`libtool' will default to `CC'; this tag always exists.
This is correct if the configure.ac file contains no invocation of
LT_LANG. However, if configure.ac contains an LT_LANG invocation, and
you don't pass a --tag option, then libtool may bail out with the error
"unable to infer tagged configuration" mentioned above. You find this
behaviour implemented in libtool's 'func_infer_tag' function, right at
the beginning:
if test -n "$available_tags" && test -z "$tagname"; then
And libunistring indeed has an LT_LANG invocation:
LT_LANG([Windows Resource])
The libtool command line is synthetized by 'automake'. Automake
apparently defines
CXXLINK = $(LIBTOOL) $(AM_LIBTOOLFLAGS) ...
by default, and
CXXLINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) ...
if it has spotted an LT_LANG([CXX]) invocation.
So, the fix is to add an LT_LANG([CXX]) invocation to your configure.ac.
This fixes it for libunistring. It does not hurt to use it in the testdirs
as well, so I'm committing this:
2010-03-12 Bruno Haible <br...@clisp.org>
Fix problem with automake's definition of CXXLINK.
* gnulib-tool (func_create_testdir): After LT_INIT, also use LT_LANG.
Reported by Simon Josefsson and Ludovic Courtès.
--- gnulib-tool.orig Fri Mar 12 13:00:12 2010
+++ gnulib-tool Fri Mar 12 12:55:53 2010
@@ -4637,6 +4637,7 @@
| sed -e '/^$/d;' -e 's/AC_REQUIRE(\[\([^()]*\)\])/\1/'
if test "$libtool" = true; then
echo "LT_INIT([win32-dll])"
+ echo "LT_LANG([C++])"
echo "AM_CONDITIONAL([GL_COND_LIBTOOL], [true])"
echo "gl_cond_libtool=true"
else
@@ -4761,6 +4762,7 @@
| sed -e '/^$/d;' -e 's/AC_REQUIRE(\[\([^()]*\)\])/\1/'
if test "$libtool" = true; then
echo "LT_INIT([win32-dll])"
+ echo "LT_LANG([C++])"
echo "AM_CONDITIONAL([GL_COND_LIBTOOL], [true])"
echo "gl_cond_libtool=true"
else
