Factor out tribits_add_test_example_directories_assert_call_context() (…

…TriBITSPub#200)

This eliminates a lot of dupication, reduces the number of lines of code, and
removes a bunch of clutter from the functions tribits_add_test_directories()
and tribits_add_example_directories().  Win, win, win.

I noticed this while working on TriBITSPub#510.

tribits/core/package_arch/TribitsPackageMacros.cmake

@@ -408,40 +408,8 @@ endmacro()
 #
 macro(tribits_add_test_directories)
 
-  if (CURRENTLY_PROCESSING_SUBPACKAGE)
-
-    # This is a subpackage being processed
-
-    if(NOT ${SUBPACKAGE_FULLNAME}_TRIBITS_SUBPACKAGE_CALLED)
-      tribits_report_invalid_tribits_usage(
-        "Must call tribits_subpackage() before tribits_add_test_directories()"
-        " in ${CURRENT_SUBPACKAGE_CMAKELIST_FILE}")
-    endif()
-
-    if(${SUBPACKAGE_FULLNAME}_TRIBITS_SUBPACKAGE_POSTPROCESS_CALLED)
-      tribits_report_invalid_tribits_usage(
-        "Must call tribits_add_test_directories() before"
-        " tribits_subpackage_postprocess() in"
-        " ${CURRENT_SUBPACKAGE_CMAKELIST_FILE}")
-    endif()
-
-  else()
-
-    # This is a package being processed
-
-    if(NOT ${PACKAGE_NAME}_TRIBITS_PACKAGE_DECL_CALLED)
-      tribits_report_invalid_tribits_usage(
-        "Must call tribits_package() or tribits_package_decl() before"
-        " tribits_add_test_directories() in ${TRIBITS_PACKAGE_CMAKELIST_FILE}")
-    endif()
-
-    if(${PACKAGE_NAME}_TRIBITS_PACKAGE_POSTPROCESS_CALLED)
-      tribits_report_invalid_tribits_usage(
-        "Must call tribits_add_test_directories() before "
-        " tribits_package_postprocess() in ${TRIBITS_PACKAGE_CMAKELIST_FILE}")
-    endif()
-
-  endif()
+  tribits_add_test_example_directories_assert_call_context(
+    tribits_add_test_directories)
 
   if(${PACKAGE_NAME}_ENABLE_TESTS OR ${PARENT_PACKAGE_NAME}_ENABLE_TESTS)
     foreach(TEST_DIR ${ARGN})
@@ -563,46 +531,57 @@ endmacro()
 #
 macro(tribits_add_example_directories)
 
+  tribits_add_test_example_directories_assert_call_context(
+    tribits_add_example_directories)
+
+  if(${PACKAGE_NAME}_ENABLE_EXAMPLES  OR ${PARENT_PACKAGE_NAME}_ENABLE_EXAMPLES)
+    foreach(EXAMPLE_DIR ${ARGN})
+      tribits_trace_file_processing(PACKAGE  ADD_SUBDIR
+        "${CMAKE_CURRENT_SOURCE_DIR}/${EXAMPLE_DIR}/CMakeLists.txt")
+      add_subdirectory(${EXAMPLE_DIR})
+    endforeach()
+  endif()
+
+endmacro()
+
+
+macro(tribits_add_test_example_directories_assert_call_context  macroName)
+
   if (CURRENTLY_PROCESSING_SUBPACKAGE)
 
     # This is a subpackage being processed
+
     if(NOT ${SUBPACKAGE_FULLNAME}_TRIBITS_SUBPACKAGE_CALLED)
       tribits_report_invalid_tribits_usage(
-        "Must call tribits_subpackage() before tribits_add_example_directories()"
+        "Must call tribits_subpackage() before ${macroName}()"
         " in ${CURRENT_SUBPACKAGE_CMAKELIST_FILE}")
     endif()
 
     if(${SUBPACKAGE_FULLNAME}_TRIBITS_SUBPACKAGE_POSTPROCESS_CALLED)
       tribits_report_invalid_tribits_usage(
-        "Must call tribits_add_example_directories() before "
-        " tribits_subpackage_postprocess() in ${CURRENT_SUBPACKAGE_CMAKELIST_FILE}")
+        "Must call ${macroName}() before"
+        " tribits_subpackage_postprocess() in"
+        " ${CURRENT_SUBPACKAGE_CMAKELIST_FILE}")
     endif()
 
   else()
 
     # This is a package being processed
+
     if(NOT ${PACKAGE_NAME}_TRIBITS_PACKAGE_DECL_CALLED)
       tribits_report_invalid_tribits_usage(
         "Must call tribits_package() or tribits_package_decl() before"
-        " tribits_add_example_directories() in ${TRIBITS_PACKAGE_CMAKELIST_FILE}")
+        " ${macroName}() in ${TRIBITS_PACKAGE_CMAKELIST_FILE}")
     endif()
 
     if(${PACKAGE_NAME}_TRIBITS_PACKAGE_POSTPROCESS_CALLED)
       tribits_report_invalid_tribits_usage(
-        "Must call tribits_add_example_directories() before "
+        "Must call ${macroName}() before "
         " tribits_package_postprocess() in ${TRIBITS_PACKAGE_CMAKELIST_FILE}")
     endif()
 
   endif()
 
-  if(${PACKAGE_NAME}_ENABLE_EXAMPLES OR ${PARENT_PACKAGE_NAME}_ENABLE_EXAMPLES)
-    foreach(EXAMPLE_DIR ${ARGN})
-      tribits_trace_file_processing(PACKAGE  ADD_SUBDIR
-        "${CMAKE_CURRENT_SOURCE_DIR}/${EXAMPLE_DIR}/CMakeLists.txt")
-      add_subdirectory(${EXAMPLE_DIR})
-    endforeach()
-  endif()
-
 endmacro()