feature-skip-preprocess-on-restart

docs/documentation/case.md

@@ -689,6 +689,8 @@ The value of `dt` needs to be sufficiently small to satisfy the Courant-Friedric
 `t_step_save` is the time step interval for data output during simulation.
 To newly start the simulation, set `t_step_start = 0`.
 To restart the simulation from $k$-th time step, set `t_step_start = k`; see @ref running "Restarting Cases".
+When `t_step_start > 0`, `./mfc.sh run` skips `pre_process` by default, since it would otherwise overwrite the
+restart data being resumed from. Pass `-t pre_process` explicitly (as in the restart workflow) if regenerating it is intended.
 
 ##### Adaptive Time-Stepping
 

toolchain/mfc/args.py

@@ -86,8 +86,10 @@ def custom_error(message):
 
         subparser.error = custom_error
 
-    args: dict = vars(parser.parse_args(sys.argv[1:extra_index]))
+    cli_argv = sys.argv[1:extra_index]
+    args: dict = vars(parser.parse_args(cli_argv))
     args["--"] = sys.argv[extra_index + 1 :]
+    args["targets_explicit"] = any(tok in ("-t", "--targets") for tok in cli_argv)
 
     # Handle --help at top level
     if args.get("help") and args["command"] is None:

toolchain/mfc/lint_docs.py

@@ -69,6 +69,8 @@
     "zeros_default",
     # Analytic expression language: module name (not a case param)
     "m_constants",
+    # Build/run target name (not a case param)
+    "pre_process",
 }
 
 # Docs to check for parameter references, with per-file skip sets

toolchain/mfc/run/run.py

@@ -9,7 +9,7 @@
 from mako.lookup import TemplateLookup
 from mako.template import Template
 
-from ..build import REQUIRED_TARGETS, SIMULATION, build, get_targets
+from ..build import PRE_PROCESS, REQUIRED_TARGETS, SIMULATION, build, get_targets
 from ..common import MFC_ROOT_DIR, MFC_TEMPLATE_DIR, MFCException, does_command_exist, file_dump_yaml, file_read, file_write, format_list_to_string, isspace, system
 from ..printer import cons
 from ..state import ARG, ARGS, CFG, gpuConfigOptions
@@ -157,9 +157,14 @@ def __execute_job_script(qsystem: queues.QueueSystem):
 
 
 def run(targets=None, case=None):
+    targets_explicit = targets is not None or ARG("targets_explicit", False)
     targets = get_targets(list(REQUIRED_TARGETS) + (targets or ARG("targets")))
     case = case or input.load(ARG("input"), ARG("--"))
 
+    if not targets_explicit and PRE_PROCESS in targets and (int(case.params.get("t_step_start", 0)) > 0 or int(case.params.get("n_start", 0)) > 0):
+        cons.print("[yellow]t_step_start > 0: skipping pre_process so it doesn't overwrite the restart data being resumed from. Pass -t pre_process explicitly to force it.[/yellow]")
+        targets = [t for t in targets if t is not PRE_PROCESS]
+
     build(targets)
 
     verbosity = ARG("verbose")