Use a export-file for Windows builds

Apparently even that doesn't make check-internal-symbols.sh happy with
mingw32.  Going to disable that for DLLs again, but hopefully the
export-file is doing *something*.

configure.ac

@@ -70,7 +70,7 @@ if test "x$GCC" = "xyes"; then
 	CXXFLAGS="$CXXFLAGS -Wcast-align"
 
 	case "$host" in
-		*-mingw*)
+		*-*-mingw*)
 		;;
 		*)
 			# Hide inline methods
@@ -86,6 +86,18 @@ if test "x$GCC" = "xyes"; then
 	esac
 fi
 
+AC_MSG_CHECKING([for native Win32])
+case "$host" in
+  *-*-mingw*)
+    hb_os_win32=yes
+    ;;
+  *)
+    hb_os_win32=no
+    ;;
+esac
+AC_MSG_RESULT([$hb_os_win32])
+AM_CONDITIONAL(OS_WIN32, test "$hb_os_win32" = "yes")
+
 dnl ==========================================================================
 
 have_ot=true

src/Makefile.am

@@ -164,16 +164,36 @@ endif
 DIST_SUBDIRS += hb-old
 
 
+
+# Put the library together
+
+if OS_WIN32
+export_symbols = -export-symbols harfbuzz.def
+harfbuzz_def_dependency = harfbuzz.def
+endif
+
 # Use a C linker, not C++; Don't link to libstdc++
 libharfbuzz_la_LINK = $(LINK) $(libharfbuzz_la_LDFLAGS)
 libharfbuzz_la_SOURCES = $(HBSOURCES) $(HBHEADERS)
 nodist_libharfbuzz_la_SOURCES = $(nodist_HBSOURCES)
 libharfbuzz_la_CPPFLAGS = $(HBCFLAGS)
-libharfbuzz_la_LDFLAGS = $(AM_LDFLAGS) -version-info $(HB_LIBTOOL_VERSION_INFO) -no-undefined
+libharfbuzz_la_LDFLAGS = $(AM_LDFLAGS) -version-info $(HB_LIBTOOL_VERSION_INFO) $(export_symbols) -no-undefined
 libharfbuzz_la_LIBADD = $(HBLIBS)
+libharfbuzz_la_DEPENDENCIES = $(harfbuzz_def_dependency)
 pkginclude_HEADERS = $(HBHEADERS)
 nodist_pkginclude_HEADERS = hb-version.h
 
+CLEANFILES += harfbuzz.def
+harfbuzz.def: $(HBHEADERS)
+	$(AM_V_GEN) (echo EXPORTS; \
+	(cat $^ || echo 'hb_ERROR ()' ) | \
+	$(EGREP) '^hb_.* \(' | \
+	sed -e 's/ (.*//' | \
+	LANG=C sort; \
+	echo LIBRARY libharfbuzz-$(HB_VERSION_MAJOR).dll; \
+	) >"$@.tmp"
+	@ ! grep -q hb_ERROR "$@.tmp" && mv "$@.tmp" "$@" || ($(RM) "$@"; false)
+
 
 GENERATORS = \
 	gen-arabic-table.py \