fix: let a platform's only target filter nothing

scripts/check_freshness.py

@@ -436,6 +436,14 @@ def check_targets(
         with path.open(encoding="utf-8") as fh:
             old = yaml_load(fh) or {}
         module = scrapers.get(platform)
+        targets = old.get("targets") or {}
+        if module is None and targets and all(
+            (t or {}).get("cores", []) is None for t in targets.values()
+        ):
+            # Every core the platform declares runs on these targets: the list
+            # is the platform's own and has nothing of its own to age.
+            return [Finding("targets", platform, OK, local="static",
+                            detail="every declared core")]
         if module is None:
             # No scraper: a hand-written file has no upstream to diff against,
             # so only its age and its core names can be reported.

scripts/common.py

@@ -437,10 +437,14 @@ def load_target_config(
     platform_name: str,
     target: str,
     platforms_dir: str = "platforms",
-) -> set[str]:
+) -> set[str] | None:
     """Load target config and return the set of core names for the given target.
 
     Resolves aliases from _overrides.yml, applies add_cores/remove_cores.
+    A target whose cores are null runs every core the platform declares and
+    returns None, which filters nothing: the platforms with a single target
+    (RetroBat on Windows, RetroDECK, RomM in the browser) kept a hand list
+    that dropped 98 RetroBat cores and 300 RetroDECK ones.
     Raises ValueError if target is unknown (with list of available targets).
     Raises FileNotFoundError if no target file exists for the platform.
     """
@@ -470,7 +474,10 @@ def load_target_config(
             msg += f"\nAliases: {', '.join(sorted(aliases))}"
         raise ValueError(msg)
 
-    cores = set(str(c) for c in targets[canonical].get("cores", []))
+    declared = (targets[canonical] or {}).get("cores")
+    if declared is None:
+        return None
+    cores = set(str(c) for c in declared)
     return apply_target_overrides(cores, overrides, canonical)
 
 
@@ -515,18 +522,30 @@ def list_available_targets(
     result = []
     for tname, tdata in sorted(data.get("targets", {}).items()):
         aliases = (overrides.get(tname) or {}).get("aliases", [])
-        cores = {str(c) for c in tdata.get("cores", [])}
+        declared = (tdata or {}).get("cores")
+        # None: the target runs every core the platform declares.
+        count = (
+            None if declared is None
+            else len(apply_target_overrides({str(c) for c in declared}, overrides, tname))
+        )
         result.append(
             {
                 "name": tname,
-                "architecture": tdata.get("architecture", ""),
-                "core_count": len(apply_target_overrides(cores, overrides, tname)),
+                "architecture": (tdata or {}).get("architecture", ""),
+                "core_count": count,
                 "aliases": aliases,
             }
         )
     return result
 
 
+def target_listing_line(row: dict) -> str:
+    """One --list-targets row, as verify and generate_pack print it."""
+    aliases = f" (aliases: {', '.join(row['aliases'])})" if row["aliases"] else ""
+    count = "all" if row["core_count"] is None else str(row["core_count"])
+    return f"  {row['name']:30s} {row['architecture']:10s} {count:>4s} cores{aliases}"
+
+
 HASH_EXACT_RESOLUTION_STATUSES = frozenset(
     {
         "sha1_exact",

scripts/generate_pack.py

@@ -30,6 +30,7 @@ from pathlib import Path
 sys.path.insert(0, os.path.dirname(__file__))
 from common import resolve_platform_cores as _platform_cores
 from common import (
+    target_listing_line,
     suggest_names,
     require_platform,
     apply_target_overrides,
@@ -2897,10 +2898,7 @@ def main():
             print(f"No targets configured for platform '{args.platform}'")
             return
         for t in targets:
-            aliases = f" (aliases: {', '.join(t['aliases'])})" if t["aliases"] else ""
-            print(
-                f"  {t['name']:30s} {t['architecture']:10s} {t['core_count']:>4d} cores{aliases}"
-            )
+            print(target_listing_line(t))
         return
 
     _validate_args(args, parser)

scripts/verify.py

@@ -34,6 +34,7 @@ import slots
 
 sys.path.insert(0, os.path.dirname(__file__))
 from common import (
+    target_listing_line,
     suggest_names,
     require_platform,
     archive_entry,
@@ -2029,10 +2030,7 @@ def _run_listing(args: argparse.Namespace, parser: argparse.ArgumentParser) -> N
             print(f"No targets configured for platform '{args.platform}'")
             return
         for t in targets:
-            aliases = f" (aliases: {', '.join(t['aliases'])})" if t["aliases"] else ""
-            print(
-                f"  {t['name']:30s} {t['architecture']:10s} {t['core_count']:>4d} cores{aliases}"
-            )
+            print(target_listing_line(t))
 
 
 def main():