configure: Windows cross-compilation fixes

CARES_BUILDING_LIBRARY and CARES_STATICLIB no longer defined in ares_config.h,
configure will generate appropriate conditionals so that mentioned symbols
get defined and used in Makefile derived from Makefile.am at compilation time.

Makefile.am

@@ -103,6 +103,20 @@ libcares_la_LDFLAGS = $(UNDEF) $(VER)
 # Add -Werror if defined
 CFLAGS += @CARES_CFLAG_EXTRAS@
 
+# For Windows build targets, when building or using static c-ares
+if USE_CPPFLAG_CARES_STATICLIB
+AM_CPPFLAGS = -DCARES_STATICLIB
+else
+AM_CPPFLAGS =
+endif
+
+# For Windows build targets, when building c-ares library
+if USE_CPPFLAG_CARES_BUILDING_LIBRARY
+libcares_la_CPPFLAGS = $(AM_CPPFLAGS) -DCARES_BUILDING_LIBRARY
+else
+libcares_la_CPPFLAGS = $(AM_CPPFLAGS)
+endif
+
 # Makefile.inc provides the CSOURCES and HHEADERS defines
 include Makefile.inc
 
@@ -117,14 +131,17 @@ libcares_la_HEADERS = ares.h ares_version.h ares_dns.h \
 ahost_SOURCES = ahost.c $(SAMPLESOURCES) $(SAMPLEHEADERS)
 ahost_LDADD = $(top_builddir)/libcares.la
 ahost_CFLAGS = $(AM_CFLAGS)
+ahost_CPPFLAGS = $(AM_CPPFLAGS)
 
 adig_SOURCES = adig.c $(SAMPLESOURCES) $(SAMPLEHEADERS)
 adig_LDADD = $(top_builddir)/libcares.la
 adig_CFLAGS = $(AM_CFLAGS)
+adig_CPPFLAGS = $(AM_CPPFLAGS)
 
 acountry_SOURCES = acountry.c $(SAMPLESOURCES) $(SAMPLEHEADERS)
 acountry_LDADD = $(top_builddir)/libcares.la
 acountry_CFLAGS = $(AM_CFLAGS)
+acountry_CPPFLAGS = $(AM_CPPFLAGS)
 
 SOURCEDMANDIR = man3
 SOURCEDMANPAGES = ares_init.3

configure.ac

@@ -128,15 +128,17 @@ dnl libtool setup
 AC_PROG_LIBTOOL
 
 AC_MSG_CHECKING([if we need CARES_BUILDING_LIBRARY])
+use_cppflag_cares_building_library="no"
+use_cppflag_cares_staticlib="no"
 case $host in
   *-*-mingw*)
-    AC_DEFINE(CARES_BUILDING_LIBRARY, 1, [when building c-ares library])
     AC_MSG_RESULT(yes)
+    use_cppflag_cares_building_library="yes"
     AC_MSG_CHECKING([if we need CARES_STATICLIB])
     if test "X$enable_shared" = "Xno"
     then
-      AC_DEFINE(CARES_STATICLIB, 1, [when not building a shared library])
       AC_MSG_RESULT(yes)
+      use_cppflag_cares_staticlib="yes"
     else
       AC_MSG_RESULT(no)
     fi
@@ -145,6 +147,8 @@ case $host in
     AC_MSG_RESULT(no)
     ;;
 esac
+AM_CONDITIONAL(USE_CPPFLAG_CARES_BUILDING_LIBRARY, test x$use_cppflag_cares_building_library = xyes)
+AM_CONDITIONAL(USE_CPPFLAG_CARES_STATICLIB, test x$use_cppflag_cares_staticlib = xyes)
 
 dnl **********************************************************************
 dnl platform/compiler/architecture specific checks/flags