Spit out a warning if CLHEP::CLHEP the target already exists

AIDASoft · Sep 15, 2023 · 92364aa · 92364aa
1 parent 8e9f5d1
commit 92364aa
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/cmake/DD4hepBuild.cmake b/cmake/DD4hepBuild.cmake
@@ -826,9 +826,11 @@ MACRO(DD4HEP_SETUP_GEANT4_TARGETS)
 
     if(Geant4_builtin_clhep_FOUND)
       dd4hep_debug("Using Geant4 internal CLHEP")
-      IF(NOT TARGET CLHEP::CLHEP)
+      if(TARGET CLHEP::CLHEP)
+        message(WARNING "CLHEP::CLHEP already exists, this may cause problems if there are two different installations of CLHEP, one from Geant4 and one external")
+      else if(NOT TARGET CLHEP::CLHEP)
         ADD_LIBRARY(CLHEP::CLHEP INTERFACE IMPORTED GLOBAL)
-      ENDIF()
+      endif()
       SET_TARGET_PROPERTIES(CLHEP::CLHEP
         PROPERTIES
         INTERFACE_INCLUDE_DIRECTORIES "${Geant4_INCLUDE_DIRS}"