refactor: [config] move overrides from flow base to config loading stage

This is to ensure that the saved project config is already resolved
otherwise the overrides mechanism would need to be implemented in
any code that loads the project config.

Without this change, the report generation code can't see the correct
rel_path field as it is overridden in the flow object after being saved
as part of the project config.

Signed-off-by: James McCorrie <james.mccorrie@lowrisc.org>

Author: machshev

src/dvsim/config/load.py

@@ -421,6 +421,23 @@ def _merge_use_cfgs(
     return {k: v for k, v in cfg.items() if k != "use_cfgs"}
 
 
+def _apply_overrides(cfg: Mapping[str, object]) -> Mapping[str, object]:
+    """Apply overrides that are found in the config."""
+    if "overrides" not in cfg:
+        return cfg
+
+    overrides = cfg["overrides"]
+    log.debug("applying overrides: %s", overrides)
+
+    # copy and filter out the overrides field
+    new_cfg = {k: v for k, v in cfg.items() if k != "overrides"}
+
+    # apply the overrides
+    new_cfg.update({o["name"]: o["value"] for o in overrides})
+
+    return new_cfg
+
+
 def load_cfg(
     path: Path,
     *,
@@ -502,6 +519,9 @@ def load_cfg(
         wildcard_values=path_resolution_wildcards,
     )
 
+    # Apply overrides
+    cfg_data = _apply_overrides(cfg=cfg_data)
+
     # Import any use_cfgs child config files
     return _merge_use_cfgs(
         top_cfg=cfg_data,

src/dvsim/flow/base.py

@@ -81,10 +81,6 @@ def __init__(
         # process' environment.
         self.exports = []
 
-        # Add overrides using the overrides keyword - existing attributes
-        # are overridden with the override values.
-        self.overrides = []
-
         # Add a notion of "primary" cfg - this is indicated using
         # a special key 'use_cfgs' within the hjson cfg.
         self.is_primary_cfg = child_configs is not None
@@ -127,15 +123,14 @@ def __init__(
         # Merge in the values from the loaded config file.
         self.__dict__.update(self._config_data)
 
-        # Is this a primary config? If so, we need to load up all the child
-        # configurations at this point. If not, we place ourselves into
-        # self.cfgs and consider ourselves a sort of "degenerate primary
-        # configuration".
+        # Expand wildcards. If subclasses need to mess around with parameters
+        # after merging the hjson but before expansion, they can override
+        # _expand and add the code at the start.
+        self._expand()
 
-        if self.rel_path == "":
-            self.rel_path = self.flow_cfg_file.parent.relative_to(
-                self._project_cfg.root_path,
-            )
+        # Construct the path variables after variable expansion.
+        self.results_dir = Path(self.scratch_base_path) / "reports" / self.rel_path
+        self.results_page = self.results_dir / self.results_html_name
 
     def _expand(self) -> None:
         """Expand wildcards after merging hjson.