INTERFACE_LIBRARY: Avoid codepaths which set unneeded properties.

As an INTERFACE_LIBRARY has no direct link dependencies, we can
short-circuit in cmGeneratorExpressionEvaluator and
in cmGlobalGenerator::CheckLocalGenerators.

As they do not generate any output directly, any generate- or install-
related code acn also be short-circuited. Many of the local generators
already do this.

Because only INTERFACE related properties make sense on INTERFACE_LIBRARY
targets, avoid setting other properties, for example via defaults.

1 files changed, 9 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 20cd15e..e6f3d94 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1309,6 +1309,11 @@ void cmGlobalGenerator::FinalizeTargetCompileInfo()
       {
       cmTarget* t = &ti->second;
 
+      if (t->GetType() == cmTarget::INTERFACE_LIBRARY)
+        {
+        continue;
+        }
+
       t->AppendBuildInterfaceIncludes();
 
       for (std::vector<cmValueWithOrigin>::const_iterator it
@@ -1461,6 +1466,10 @@ void cmGlobalGenerator::CheckLocalGenerators()
     for (cmTargets::iterator l = targets.begin();
          l != targets.end(); l++)
       {
+      if (l->second.GetType() == cmTarget::INTERFACE_LIBRARY)
+        {
+        continue;
+        }
       const cmTarget::LinkLibraryVectorType& libs =
         l->second.GetOriginalLinkLibraries();
       for(cmTarget::LinkLibraryVectorType::const_iterator lib = libs.begin();