configure fails to enable readline if ncurses is built with separate tinfo lib and "--as-needed" linker flag is used about asymptote

[johncbowman]

Can you try out the latest git development source, which fixes some pkg-config issues?

[tifv]

Yes, I have tried. It doesn't work.

It seems that for the ncurses check to succeed, -ltinfo should already be in $LIBS. But the tinfo check done with CHECK_LIB_STATIC autoconf macro, even successfull, doesn't append -ltinfo to $LIBS.

For example, replacing the line
CHECK_LIB_STATIC(tinfo,tinfo,tgetent,HAVE_LIBTINFO,AC_MSG_NOTICE([perhaps tgetent is in -lncurses]))
with
AC_CHECK_LIB(tinfo, tgetent)
on my system correctly prepends -ltinfo to $LIBS after the check and allows subsequent ncurses check to succeed.

As for pkg-config, it seems to work fine on my system:

$ pkg-config --libs tinfo
-ltinfo
$ pkg-config --libs ncurses
-lncurses -ltinfo

However, the CHECK_LIB_STATIC autoconf macro appends pkg-config output to $LDFLAGS during the check, but not to $LIBS. In linker arguments, $LDFLAGS goes before the conftest.cpp and $LIBS goes after it. Because --as-needed linker flag makes the order of linked libraries important, this results in a failed check.

[tifv]

This is somewhat unfamiliar territory for me, but it seems that according to AC_CHECK_LIB documentation, any extra libraries required for correct linkage, such as produced by pkg-config --libs, should go in its fifth argument? Like this:

--- a/configure.ac
+++ b/configure.ac
@@ -344,7 +344,7 @@
 [
 LDFLAGS=$LDFLAGS_SAVE
 $5
-])
+],$PKG_FLAGS)
 ]
 else
 [
@@ -352,7 +352,7 @@
 $5
 ]
 fi
-)]
+,$PKG_FLAGS)]
 )
 
 if test "x$enable_readline" != "xno"; then

[johncbowman]

Yes, that seems like a good solution. I think it is better than the one I came up:

--- a/configure.ac
+++ b/configure.ac
@@ -333,14 +333,24 @@ PKG_FLAGS=-l"$2"
 echo will try linking with $PKG_FLAGS
 fi
 LDFLAGS_SAVE=$LDFLAGS
-LDFLAGS="$LDFLAGS ""$STATIC ""$PKG_FLAGS ""$DYNAMIC "
-AC_CHECK_LIB($2,$3,AC_DEFINE($4,1,DEFINE_LIB($2)),
+LDFLAGS="$LDFLAGS "$STATIC"$PKG_FLAGS "$DYNAMIC
+AC_CHECK_LIB($2,$3,
+[
+LIBS=$LIBS$STATIC"$PKG_FLAGS "$DYNAMIC
+LDFLAGS=$LDFLAGS_SAVE
+AC_DEFINE($4,1,DEFINE_LIB($2))
+],
 if test "x$enable_static" = "xyes"; then
 [
 echo "Static library not found; will check for dynamic version"
 LDFLAGS="$LDFLAGS_SAVE ""$PKG_FLAGS "
 AS_UNSET([ac_cv_lib_$2_$3])
-AC_CHECK_LIB($2,$3,AC_DEFINE($4,1,DEFINE_LIB($2)),
+AC_CHECK_LIB($2,$3,
+[
+LIBS=$LIBS"$PKG_FLAGS "
+LDFLAGS=$LDFLAGS_SAVE
+AC_DEFINE($4,1,DEFINE_LIB($2))
+],
 [
 LDFLAGS=$LDFLAGS_SAVE
 $5

[johncbowman]

Fixed in commit 99bd093.