Honor $<LINK_ONLY> when checking interface properties

Callers of cmTarget::GetLinkImplementationClosure are interested in the
set of targets whose interface properties propagate to the current
target.  This excludes targets guarded by $<LINK_ONLY>.

Teach the CompatibleInterface test to cover suppression of interface
compatibility tests with $<LINK_ONLY>.  Although this is not recommended
in practice, it is a way of covering the above behavior.

1 files changed, 7 insertions, 1 deletions

diff --git a/Tests/CompatibleInterface/main.cpp b/Tests/CompatibleInterface/main.cpp
index e23625a..d20b64b 100644
--- a/Tests/CompatibleInterface/main.cpp
+++ b/Tests/CompatibleInterface/main.cpp
@@ -40,8 +40,14 @@ enum {
 
 #include "iface2.h"
 
+int foo();
+#ifdef _WIN32
+__declspec(dllimport)
+#endif
+int bar();
+
 int main(int argc, char **argv)
 {
   Iface2 if2;
-  return if2.foo();
+  return if2.foo() + foo() + bar();
 }