ENH: Implemented link-interface specification feature.

  - Shared libs and executables with exports may now have
    explicit transitive link dependencies specified
  - Created LINK_INTERFACE_LIBRARIES and related properties
  - Exported targets get the interface libraries as their
    IMPORTED_LINK_LIBRARIES property.
  - The export() and install(EXPORT) commands now give
    an error when a linked target is not included since
    the user can change the interface libraries instead
    of adding the target.

1 files changed, 9 insertions, 5 deletions

diff --git a/Source/cmExportInstallFileGenerator.cxx b/Source/cmExportInstallFileGenerator.cxx
index 82af4e1..14bb816 100644
--- a/Source/cmExportInstallFileGenerator.cxx
+++ b/Source/cmExportInstallFileGenerator.cxx
@@ -267,9 +267,13 @@ cmExportInstallFileGenerator
 ::ComplainAboutMissingTarget(cmTarget* target, const char* dep)
 {
   cmOStringStream e;
-  e << "WARNING: INSTALL(EXPORT \"" << this->Name << "\" ...) "
-    << "includes target " << target->GetName()
-    << " which links to target \"" << dep
-    << "\" that is not in the export set.";
-  cmSystemTools::Message(e.str().c_str());
+  e << "INSTALL(EXPORT \"" << this->Name << "\" ...) "
+    << "includes target \"" << target->GetName()
+    << "\" which links to target \"" << dep
+    << "\" that is not in the export set.  "
+    << "If the link dependency is not part of the public interface "
+    << "consider setting the LINK_INTERFACE_LIBRARIES property on "
+    << "target \"" << target->GetName() << "\".  "
+    << "Otherwise add it to the export set.";
+  cmSystemTools::Error(e.str().c_str());
 }