The link interface of MODULE libraries is empty (#11945)

MODULE libraries cannot be linked into other libraries and executables
(just like executables without ENABLE_EXPORTS).  Set the MODULE target
link interface to be empty.  This allows such targets to be installed in
an EXPORT set without including all their private implementation
dependencies.

1 files changed, 7 insertions, 3 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 72efce308..b5900c474 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -4278,9 +4278,13 @@ bool cmTarget::ComputeLinkInterface(const char* config, LinkInterface& iface)
       }
     }
 
-  // There is no implicit link interface for executables, so if none
-  // was explicitly set, there is no link interface.
-  if(!explicitLibraries && this->GetType() == cmTarget::EXECUTABLE)
+  // There is no implicit link interface for executables or modules
+  // so if none was explicitly set then there is no link interface.
+  // Note that CMake versions 2.2 and below allowed linking to modules.
+  bool canLinkModules = this->Makefile->NeedBackwardsCompatibility(2,2);
+  if(!explicitLibraries &&
+     (this->GetType() == cmTarget::EXECUTABLE ||
+      this->GetType() == cmTarget::MODULE_LIBRARY && !canLinkModules))
     {
     return false;
     }