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, 15 insertions, 15 deletions

diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index 2ce4458..dc62284 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -388,14 +388,11 @@ void getCompatibleInterfaceProperties(cmTarget *target,
 
   if (!info)
     {
-    if (target->GetType() != cmTarget::INTERFACE_LIBRARY)
-      {
-      cmMakefile* mf = target->GetMakefile();
-      cmOStringStream e;
-      e << "Exporting the target \"" << target->GetName() << "\" is not "
-          "allowed since its linker language cannot be determined";
-      mf->IssueMessage(cmake::FATAL_ERROR, e.str());
-      }
+    cmMakefile* mf = target->GetMakefile();
+    cmOStringStream e;
+    e << "Exporting the target \"" << target->GetName() << "\" is not "
+        "allowed since its linker language cannot be determined";
+    mf->IssueMessage(cmake::FATAL_ERROR, e.str());
     return;
     }
 
@@ -447,15 +444,18 @@ void cmExportFileGenerator::PopulateCompatibleInterfaceProperties(
   getPropertyContents(target, "COMPATIBLE_INTERFACE_NUMBER_MAX",
                       ifaceProperties);
 
-  getCompatibleInterfaceProperties(target, ifaceProperties, 0);
+  if (target->GetType() != cmTarget::INTERFACE_LIBRARY)
+    {
+    getCompatibleInterfaceProperties(target, ifaceProperties, 0);
 
-  std::vector<std::string> configNames;
-  target->GetMakefile()->GetConfigurations(configNames);
+    std::vector<std::string> configNames;
+    target->GetMakefile()->GetConfigurations(configNames);
 
-  for (std::vector<std::string>::const_iterator ci = configNames.begin();
-    ci != configNames.end(); ++ci)
-    {
-    getCompatibleInterfaceProperties(target, ifaceProperties, ci->c_str());
+    for (std::vector<std::string>::const_iterator ci = configNames.begin();
+      ci != configNames.end(); ++ci)
+      {
+      getCompatibleInterfaceProperties(target, ifaceProperties, ci->c_str());
+      }
     }
 
   for (std::set<std::string>::const_iterator it = ifaceProperties.begin();