BLD: Get netCDF4 build working on Windows.

Most changes are to get plugins working.
libdispatchdreg.c went in in Unidata#2460,
after I'd done it here.

Summary of individual changes below.

BLD: Remove declspec(dllexport); in dreg.c.

By removing the explicit handling, the automatic handling
(equivalent to --export-all-symbols with recent GNU tools)
will be enabled again, so the generated library will have
more than one function exported.

BLD: Link plugins against libnetcdf on Cygwin.

BLD: Add AM_LDFLAGS to plugin _LDFLAGS to pass -no-undefined.

BLD: Link ncz*filters plugins against libnetcdf.

BLD: Add AM_LDFLAGS to test plugin _LDFLAGS.

Also move rpath from AM_LDFLAGS to test plugin _LDFLAGS.

TST: Don't run nczarr_test/run_specific_filters.sh on Cygwin.

It takes over half an hour to complete, where the others take a minute or less.

TST: Try to find the hanging Cygwin test.

libdispatch/dreg.c

@@ -19,7 +19,6 @@
 #ifdef _WIN32
 __declspec(dllexport)
 #endif
-
 int
 getmountpoint(char* keyvalue, size_t size)
 {

nczarr_test/Makefile.am

@@ -96,7 +96,7 @@ TESTS += run_nczfilter.sh
 # Echo filter tests from nc_test4
 check_PROGRAMS += testfilter testfilter_misc testfilter_order testfilter_repeat testfilter_multi test_filter_avail
 TESTS += run_filter.sh 
-TESTS += run_unknown.sh 
+TESTS += run_unknown.sh
 TESTS += run_specific_filters.sh
 
 endif #ENABLE_FILTER_TESTING
@@ -116,8 +116,10 @@ zs3parse_SOURCES = zs3parse.c
 if ENABLE_NCZARR_S3
 noinst_PROGRAMS += s3util
 s3util_SOURCES = s3util.c
+if !ISCYGWIN
 TESTS += run_s3_cleanup.sh
 endif
+endif
 
 # Given a netcdf4|NCZarr file, dump the actual chunk contents.
 # Used to validate nczarr chunking code.

plugins/Makefile.am

@@ -5,7 +5,7 @@
 include $(top_srcdir)/lib_flags.am
 
 AM_LDFLAGS += -module -avoid-version -shared -export-dynamic	\
- -rpath ${abs_builddir} ${NOUNDEFINED}
+  $(NOUNDEFINED)
 
 # Create an alternate directory if not installing or for noinst installs.
 ALTPLUGINDIR = ${abs_top_builddir}/plugins/plugindir
@@ -33,6 +33,10 @@ plugin_version_info = -version-info 0:0:0
 if ISMINGW
 LDADD =  ${top_builddir}/liblib/libnetcdf.la
 endif
+if ISCYGWIN
+LDADD = $(top_builddir)/liblib/libnetcdf.la
+LIBADD = $(top_builddir)/liblib/libnetcdf.la
+endif
 
 EXTRA_DIST = CMakeLists.txt
 
@@ -55,15 +59,15 @@ lib__nch5shuffle_la_SOURCES = H5Zshuffle.c
 lib__nch5fletcher32_la_SOURCES = H5Zfletcher32.c H5checksum.c
 lib__nch5deflate_la_SOURCES = H5Zdeflate.c
 
-lib__nch5shuffle_la_LDFLAGS = ${plugin_version_info}
-lib__nch5deflate_la_LDFLAGS = ${plugin_version_info}
-lib__nch5fletcher32_la_LDFLAGS = ${plugin_version_info}
+lib__nch5shuffle_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
+lib__nch5deflate_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
+lib__nch5fletcher32_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
 
 # Need our version of szip if libsz available and we are not using HDF5
 if HAVE_SZ
 plugin_LTLIBRARIES += lib__nch5szip.la
 lib__nch5szip_la_SOURCES = H5Zszip.c H5Zszip.h
-lib__nch5szip_la_LDFLAGS = ${plugin_version_info}
+lib__nch5szip_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
 endif
 
 endif # ENABLE_NCZARR_FILTERS
@@ -72,7 +76,10 @@ if ENABLE_PLUGINS
 
 # The NCZarr codec libraries
 lib__nczstdfilters_la_SOURCES = NCZstdfilters.c
+lib__nczstdfilters_la_LIBADD = $(LIBADD)
 lib__nczhdf5filters_la_SOURCES = NCZhdf5filters.c
+lib__nczhdf5filters_la_LIBADD = $(LIBADD)
+
 
 lib__nczstdfilters_la_LDFLAGS = ${plugin_version_info}
 lib__nczhdf5filters_la_LDFLAGS= ${plugin_version_info}
@@ -82,13 +89,13 @@ plugin_LTLIBRARIES += lib__nczstdfilters.la
 
 if HAVE_BLOSC
 lib__nch5blosc_la_SOURCES = H5Zblosc.c H5Zblosc.h
-lib__nch5blosc_la_LDFLAGS = ${plugin_version_info}
+lib__nch5blosc_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
 plugin_LTLIBRARIES += lib__nch5blosc.la
 endif
 
 if HAVE_ZSTD
 lib__nch5zstd_la_SOURCES = H5Zzstd.c H5Zzstd.h
-lib__nch5zstd_la_LDFLAGS = ${plugin_version_info}
+lib__nch5zstd_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
 plugin_LTLIBRARIES += lib__nch5zstd.la
 endif
 
@@ -98,18 +105,18 @@ endif #ENABLE_PLUGINS
 # Need two distinct instances
 lib__nch5noop_la_SOURCES = H5Znoop.c H5Zutil.c h5noop.h
 lib__nch5noop1_la_SOURCES = H5Znoop1.c H5Zutil.c h5noop.h
-lib__nch5noop_la_LDFLAGS = ${plugin_version_info}
-lib__nch5noop1_la_LDFLAGS = ${plugin_version_info}
+lib__nch5noop_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS) -rpath $(abs_builddir)/.libs
+lib__nch5noop1_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS) -rpath $(abs_builddir)/.libs
 
 # The misc filter is to allow testing of filter arguments
 lib__nch5misc_la_SOURCES = H5Zmisc.c H5Zutil.c h5misc.h
-lib__nch5misc_la_LDFLAGS = ${plugin_version_info}
+lib__nch5misc_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS) -rpath $(abs_builddir)/.libs
 lib__nczmisc_la_SOURCES = NCZmisc.c
-lib__nczmisc_la_LDFLAGS = ${plugin_version_info}
+lib__nczmisc_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS) -rpath $(abs_builddir)/.libs
 
 # Provide a filter to test missing filter
 lib__nch5unknown_la_SOURCES = H5Zunknown.c
-lib__nch5unknown_la_LDFLAGS = ${plugin_version_info}
+lib__nch5unknown_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS) -rpath $(abs_builddir)/.libs
 
 tmp_LTLIBRARIES += lib__nch5noop.la lib__nch5noop1.la lib__nch5misc.la lib__nczmisc.la lib__nch5unknown.la
 
@@ -120,7 +127,7 @@ EXTRA_DIST += ${BZIP2SRC} BZIP2_LICENSE
 if HAVE_LOCAL_BZ2
 lib__nch5bzip2_la_SOURCES += ${BZIP2SRC}
 endif
-lib__nch5bzip2_la_LDFLAGS = ${plugin_version_info}
+lib__nch5bzip2_la_LDFLAGS = ${plugin_version_info} $(AM_LDFLAGS)
 plugin_LTLIBRARIES += lib__nch5bzip2.la
 
 endif #ENABLE_FILTER_TESTING