Build: clear old linux centos7 cache variables instead of printing them

More automatic and convenient to update existing configurations this way.

Also move into platform_old_libs_update.cmake where similar logic was put
already.

CMakeLists.txt

@@ -2009,24 +2009,6 @@ if(0)
   print_all_vars()
 endif()
 
-set(LIBDIR_STALE)
-
-if(UNIX AND NOT APPLE)
-  # Only search for the path if it's found on the system.
-  if(EXISTS "../lib/linux_centos7_x86_64")
-    set(LIBDIR_STALE "/lib/linux_centos7_x86_64/")
-  endif()
-endif()
-
-if(LIBDIR_STALE)
-  print_cached_vars_containing_value(
-    "${LIBDIR_STALE}"
-    "\nWARNING: found cached references to old library paths!\n"
-    "\nIt is *strongly* recommended to reference updated library paths!\n"
-  )
-endif()
-unset(LIBDIR_STALE)
-
 # Should be the last step of configuration.
 if(POSTCONFIGURE_SCRIPT)
   include(${POSTCONFIGURE_SCRIPT})

build_files/cmake/macros.cmake

@@ -1209,43 +1209,6 @@ function(print_all_vars)
   endforeach()
 endfunction()
 
-# Print a list of all cached variables with values containing `contents`.
-function(print_cached_vars_containing_value
-  contents
-  msg_header
-  msg_footer
-  )
-  set(_list_info)
-  set(_found)
-  get_cmake_property(_vars VARIABLES)
-  foreach(_var ${_vars})
-    if(DEFINED CACHE{${_var}})
-      # Skip "_" prefixed variables, these are used for internal book-keeping,
-      # not under user control.
-      string(FIND "${_var}" "_" _found)
-      if(NOT (_found EQUAL 0))
-        string(FIND "${${_var}}" "${contents}" _found)
-        if(NOT (_found EQUAL -1))
-          if(_found)
-            list(APPEND _list_info "${_var}=${${_var}}")
-          endif()
-        endif()
-      endif()
-    endif()
-  endforeach()
-  unset(_var)
-  unset(_vars)
-  unset(_found)
-  if(_list_info)
-    message(${msg_header})
-    foreach(_var ${_list_info})
-      message(" * ${_var}")
-    endforeach()
-    message(${msg_footer})
-  endif()
-  unset(_list_info)
-endfunction()
-
 macro(openmp_delayload
   projectname
   )

build_files/cmake/platform/platform_old_libs_update.cmake

@@ -3,6 +3,7 @@
 
 # Auto update existing CMake caches for new libraries
 
+# Clear cached variables whose name matches `pattern`.
 function(unset_cache_variables pattern)
   get_cmake_property(_cache_variables CACHE_VARIABLES)
   foreach(_cache_variable ${_cache_variables})
@@ -12,6 +13,30 @@ function(unset_cache_variables pattern)
   endforeach()
 endfunction()
 
+# Clear cached variables with values containing `contents`.
+function(unset_cached_varables_containting contents msg)
+  get_cmake_property(_cache_variables CACHE_VARIABLES)
+  set(_found)
+  set(_print_msg)
+  foreach(_cache_variable ${_cache_variables})
+    # Skip "_" prefixed variables, these are used for internal book-keeping,
+    # not under user control.
+    string(FIND "${_cache_variable}" "_" _found)
+    if(NOT (_found EQUAL 0))
+      string(FIND "${${_cache_variable}}" "${contents}" _found)
+      if(NOT (_found EQUAL -1))
+        if(_found)
+          unset(${_cache_variable} CACHE)
+          set(_print_msg ON)
+        endif()
+      endif()
+    endif()
+  endforeach()
+  if(_print_msg)
+    message(STATUS ${msg})
+  endif()
+endfunction()
+
 # Detect update from 3.1 to 3.2 libs.
 if(UNIX AND
    DEFINED OPENEXR_VERSION AND
@@ -63,3 +88,12 @@ if(UNIX AND
   unset_cache_variables("^TBB")
   unset_cache_variables("^USD")
 endif()
+
+if(UNIX AND (NOT APPLE) AND LIBDIR AND (EXISTS ${LIBDIR}))
+  # Only search for the path if it's found on the system.
+  set(LIBDIR_STALE "/lib/linux_centos7_x86_64/")
+  unset_cached_varables_containting(
+    "${LIBDIR_STALE}"
+    "Auto clearing old ${LIBDIR_STALE} paths from CMake configuration"
+  )
+endif()