Merge pull request #4492 from ESMCI/jgfouca/macros_copy_only_needed

Copy only necessary cmake macros to case

This implementation makes some assumptions about the context of /.../Macros.cmake, so I am only turning this on for E3SM.

I think this is a nice improvement. This will reduce the number of macros that get copied from nearly 100 to just a handful, making it easier for the user to view and edit their macros from the case.

Test suite: by-hand
Test baseline:
Test namelist changes:
Test status: [bit for bit, roundoff, climate changing]

Fixes [CIME Github issue #]

User interface changes?:

Update gh-pages html (Y/N)?:

CIME/case/case_setup.py

@@ -141,12 +141,29 @@ def _create_macros_cmake(
     ###############################################################################
     if not os.path.isfile(os.path.join(caseroot, "Macros.cmake")):
         safe_copy(os.path.join(cmake_macros_dir, "Macros.cmake"), caseroot)
-    if not os.path.exists(os.path.join(caseroot, "cmake_macros")):
-        shutil.copytree(cmake_macros_dir, case_cmake_path)
 
-    copy_depends_files(
-        mach_obj.get_machine_name(), mach_obj.machines_dir, caseroot, compiler
-    )
+    if not os.path.exists(case_cmake_path):
+        os.mkdir(case_cmake_path)
+
+    # This impl is coupled to contents of Macros.cmake
+    os_ = mach_obj.get_value("OS")
+    mach = mach_obj.get_machine_name()
+    macros = [
+        "universal.cmake",
+        os_ + ".cmake",
+        compiler + ".cmake",
+        "{}_{}.cmake".format(compiler, os),
+        mach + ".cmake",
+        "{}_{}.cmake".format(compiler, mach),
+        "CMakeLists.txt",
+    ]
+    for macro in macros:
+        repo_macro = os.path.join(cmake_macros_dir, macro)
+        case_macro = os.path.join(case_cmake_path, macro)
+        if not os.path.exists(case_macro) and os.path.exists(repo_macro):
+            safe_copy(repo_macro, case_cmake_path)
+
+    copy_depends_files(mach, mach_obj.machines_dir, caseroot, compiler)
 
 
 ###############################################################################