Re: gnulib and automake

[John W. Eaton]

On  2-Nov-2009, Benjamin Lindner wrote:

| Benjamin Lindner wrote:
| > John W. Eaton wrote:
| >> I updated the patch here:
| >>
| >>   http://jweaton.org/automake-diffs.gz
| >>
| >> Please start with this newer version of the patch if you decide to try
| >> any further debugging.
| >>
| > 
| > sure,
| > I'll start a new clean trial and report back.
| > 
| 
| It seems that one prerequisite to get shared libraries built using 
| libtool, one has to specify "-no-undefined" as libtool's link options.
| See e.g. 
| http://readlist.com/lists/lists.sourceforge.net/mingw-users/0/3404.html
| 
| What it the correct way in automake to get this flag into the link 
| options (preferably only for the *-*-mingw* platform)?
| 
| I now patch all makefile.in files, but these are generated (by automake 
| I guess). I couldn't find the source for the link commands as
| 
| libcruft_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
|       $(LIBTOOLFLAGS) --mode=link $(CXXLD) $(AM_CXXFLAGS) \
|       $(CXXFLAGS) $(libcruft_la_LDFLAGS) $(LDFLAGS) -o $@
| 
| which I modified to
| 
| libcruft_la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
|       $(LIBTOOLFLAGS) --mode=link $(CXXLD) -no-undefined $(AM_CXXFLAGS) \
|       $(CXXFLAGS) $(libcruft_la_LDFLAGS) $(LDFLAGS) -o $@
| 
| but that's not really a nice solution.
| 
| Is there an additional libtool makefile variable, something like 
| $(libtool_LDFLAGS) ?
| Or can one define an additional individual variable like 
| $(libtool_NOUNDEFINED) which is empty by default, and set to 
| "-no-undefined" for mingw platform?

Does the following change work for you?

Thanks,

jwe


diff --git a/common.mk b/common.mk
--- a/common.mk
+++ b/common.mk
@@ -141,8 +141,9 @@
 BUILD_CXX = @BUILD_CXX@
 BUILD_CXXFLAGS = @BUILD_CXXFLAGS@
 
+NO_UNDEFINED_LDFLAG = @NO_UNDEFINED_LDFLAG@
+
 LD_CXX = @LD_CXX@
-AM_LDFLAGS = @LDFLAGS@
 LD_STATIC_FLAG = @LD_STATIC_FLAG@
 #ALL_LDFLAGS = $(LIBFLAGS) $(LD_STATIC_FLAG) $(CPICFLAG) $(LDFLAGS)
 
diff --git a/configure.ac b/configure.ac
--- a/configure.ac
+++ b/configure.ac
@@ -230,13 +230,7 @@
 gcc_version=`$CC -v 2>&1 | grep "^.*gcc version" | \
   sed -e 's/^.*g.. version *//' -e 's/cygnus-//' -e 's/egcs-//'`
 case "$gcc_version" in
-  2.*)
-    if test -z "$LDFLAGS"; then
-      LDFLAGS="-g"
-      AC_MSG_NOTICE([defining LDFLAGS to be $LDFLAGS])
-    fi
-  ;;
-  1.*)
+  [12].*)
     warn_gcc_version="gcc version $gcc_version is likely to cause problems"
     AC_MSG_WARN($warn_gcc_version)
   ;;
@@ -1365,15 +1359,18 @@
 AC_CHECK_FUNCS(gethostname, [], [AC_CHECK_LIB(socket, gethostname)])
 AC_CHECK_FUNCS(getpwnam, [], [AC_CHECK_LIB(sun, getpwnam)])
 
+NO_UNDEFINED_LDFLAG=
 case "$canonical_host_type" in
   *-*-cygwin*)
    AC_CHECK_LIB(wsock32, gethostname)
    LIBS="$LIBS -lwsock32"
   ;;
   *-*-msdosmsvc* | *-*-mingw*)
-  LIBS="$LIBS -lgdi32 -lws2_32 -luser32 -lkernel32"
+    LIBS="$LIBS -lgdi32 -lws2_32 -luser32 -lkernel32"
+    NO_UNDEFINED_LDFLAG=-no-undefined
   ;;
 esac
+AC_SUBST(NO_UNDEFINED_LDFLAG)
 
 ### Type stuff.
 
diff --git a/libcruft/Makefile.am b/libcruft/Makefile.am
--- a/libcruft/Makefile.am
+++ b/libcruft/Makefile.am
@@ -29,7 +29,7 @@
 
 libcruft_la_SOURCES =
 
-libcruft_la_LDFLAGS = -release $(version)
+libcruft_la_LDFLAGS = -release $(version) $(NO_UNDEFINED_LDFLAG)
 
 libcruft_la_LIBADD = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS)
 
diff --git a/liboctave/Makefile.am b/liboctave/Makefile.am
--- a/liboctave/Makefile.am
+++ b/liboctave/Makefile.am
@@ -511,7 +511,7 @@
 
 liboctave_la_LIBADD = $(LINK_DEPS)
 
-liboctave_la_LDFLAGS = -release $(version)
+liboctave_la_LDFLAGS = -release $(version) $(NO_UNDEFINED_LDFLAG)
 
 octinclude_HEADERS = \
   $(INCS) \
diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -529,7 +529,7 @@
   $(OPT_HANDLERS) \
   $(OPT_INC)
 
-liboctinterp_la_LDFLAGS = -release $(version)
+liboctinterp_la_LDFLAGS = -release $(version) $(NO_UNDEFINED_LDFLAG)
 
 ## Order matters here.  Leave builtins.cc last, because it depends on 
 ## $(DEF_FILES), and building those requires all the sources