Let cddlib build a shared lib on Cygwin.

[jpflori]

Follow up to #13354 and #13026.

Upstream PR: cddlib/cddlib#9

Depends on #21952

Upstream: Completely fixed; Fix reported upstream

Component: porting: Cygwin

Keywords: cddlib windows cygwin

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/15872

[embray]

comment:3

Interesting that there's already a ticket for this. I've basically done the work needed for this, but a mere patch won't suffice--I think the cddlib source package needs to be rebuilt to have any hope at resolving this. See https://groups.google.com/d/msg/sage-devel/uHsTOd5sTxY/ivpNHT1MAwAJ

[embray]

Changed keywords from none to cddlib windows cygwin

[embray]

comment:5

FWIW these are the basic changes that are needed:

diff -u a/configure.in b/configure.in
--- a/configure.in      2016-11-23 11:40:16.064457900 +0100
+++ b/configure.in      2016-11-22 16:39:29.311747000 +0100
@@ -7,7 +7,18 @@
 dnl Checks for programs.
 AC_PROG_CC
 AC_PROG_INSTALL
-LT_INIT
+LT_INIT([win32-dll])
+
+AC_CANONICAL_HOST
+dnl libtool requires "-no-undefined" for win32 dll
+AC_SUBST(CDD_LDFLAGS)
+case $host_os in
+  *cygwin* | *mingw*)
+    if test x"$enable_shared" = xyes; then
+      CDD_LDFLAGS="$CDD_LDFLAGS -no-undefined"
+    fi
+;;
+esac

 dnl Checks for libraries.
 dnl Replace `main' with a function in -lg:
diff -u a/lib-src/Makefile.am b/lib-src/Makefile.am
--- a/lib-src/Makefile.am       2016-11-23 11:40:40.796141400 +0100
+++ b/lib-src/Makefile.am       2016-11-23 11:43:44.183481400 +0100
@@ -10,6 +10,8 @@
 setoper.c \
 random.c

+libcdd_la_LDFLAGS = $(CDD_LDFLAGS)
+
 include_HEADERS = \
 cdd.h \
 cddmp.h \
diff -u a/lib-src-gmp/Makefile.am b/lib-src-gmp/Makefile.am
--- a/lib-src-gmp/Makefile.am   2016-11-23 11:40:45.065312300 +0100
+++ b/lib-src-gmp/Makefile.am   2016-11-17 17:00:16.713039400 +0100
@@ -16,6 +16,8 @@
 setoper.c \
 random.c

+libcddgmp_la_LDFLAGS = $(CDD_LDFLAGS)
+
 include_HEADERS = \
 cdd.h \
 cddmp.h \

[embray]

Dependencies: #21952

[embray]

comment:6

Adding the changes needed for building shared libs on Cygwin is going to require #21952.

[saraedum]

Upstream: Not yet reported upstream; Will do shortly.

[saraedum]

comment:7

If you wouldn't mind, could you propose these changes as an issue at https://github.com/cddlib/cddlib?

[saraedum]

comment:8

I created cddlib/cddlib#8 to track this issue upstream.

[embray]

Changed upstream from Not yet reported upstream; Will do shortly. to Reported upstream. No feedback yet.

[saraedum]

comment:10

Can this be closed now?

[embray]

comment:11

I wouldn't until/unless #25344 is closed/fixed.

[mkoeppe]

comment:12

#25344 is in.

[tscrim]

Reviewer: Travis Scrimshaw

[tscrim]

Changed upstream from Reported upstream. No feedback yet. to Completely fixed; Fix reported upstream

[embray]

comment:15

Just to confirm, this does appear to (still) have worked with #25344.