Teach target_* commands to set INTERFACE properties of IMPORTED targets

Now, several `INTERFACE_*` properties can be set on `IMPORTED` targets,
not only via `set_property` and `set_target_properties` but also via
`target_compile_definitions`, `target_compile_features`,
`target_compile_options`, `target_include_directories`, `target_sources`
and `target_link_libraries`.

Fixes: #15689
Issue: #17197

1 files changed, 4 insertions, 6 deletions

diff --git a/Source/cmTargetPropCommandBase.cxx b/Source/cmTargetPropCommandBase.cxx
index 9f69dea..9a8fd96 100644
--- a/Source/cmTargetPropCommandBase.cxx
+++ b/Source/cmTargetPropCommandBase.cxx
@@ -84,17 +84,15 @@ bool cmTargetPropCommandBase::ProcessContentArgs(
     this->SetError("called with invalid arguments");
     return false;
   }
-
-  if (this->Target->IsImported()) {
-    this->HandleImportedTarget(args[0]);
-    return false;
-  }
-
   if (this->Target->GetType() == cmStateEnums::INTERFACE_LIBRARY &&
       scope != "INTERFACE") {
     this->SetError("may only set INTERFACE properties on INTERFACE targets");
     return false;
   }
+  if (this->Target->IsImported() && scope != "INTERFACE") {
+    this->SetError("may only set INTERFACE properties on IMPORTED targets");
+    return false;
+  }
 
   ++argIndex;