1 files changed, 55 insertions, 0 deletions
diff --git a/tools/check_example_pids.py b/tools/check_example_pids.py
new file mode 100644
index 000000000..d8795af34
--- /dev/null
+++ b/tools/check_example_pids.py
@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+"""Check that every example enumerates with a unique USB PID.
+
+Each example's usb_descriptors.c hardcodes its idProduct (0x40xx). Uniqueness is what
+guarantees back-to-back re-enumeration on the HIL rig and a fresh host driver match, and
+it is easy to break by hand: a new example copying a neighbour's PID, or an arithmetic
+PID (dynamic_configuration derives a second one from USB_PID). This collects every
+`#define USB_PID 0x....`, every literal `.idProduct = 0x....`, and every `USB_PID + <n>`
+derivation across examples/, and fails on any duplicate value.
+"""
+
+import re
+import sys
+from pathlib import Path
+
+EXAMPLES = Path(__file__).resolve().parents[1] / 'examples'
+
+RE_DEFINE = re.compile(r'#define\s+USB_PID\s+\(?(0x[0-9a-fA-F]+)\)?')
+RE_LITERAL = re.compile(r'\.idProduct\s*=\s*(0x[0-9a-fA-F]+)')
+RE_DERIVED = re.compile(r'\.idProduct\s*=\s*USB_PID\s*\+\s*(0x[0-9a-fA-F]+|\d+)')
+
+
+def main() -> int:
+    pids: dict[int, list[str]] = {}
+    for f in sorted(EXAMPLES.glob('*/*/src/usb_descriptors.c')):
+        text = f.read_text(errors='replace')
+        rel = f.relative_to(EXAMPLES.parent)
+        base = None
+        m = RE_DEFINE.search(text)
+        if m:
+            base = int(m.group(1), 16)
+        for m in RE_LITERAL.finditer(text):
+            pids.setdefault(int(m.group(1), 16), []).append(str(rel))
+        for m in RE_DERIVED.finditer(text):
+            if base is None:
+                print(f'{rel}: derived idProduct but no USB_PID define', file=sys.stderr)
+                return 1
+            pids.setdefault(base + int(m.group(1), 0), []).append(f'{rel} (USB_PID + {m.group(1)})')
+        # examples whose descriptor uses .idProduct = USB_PID pick up the define itself
+        if base is not None and re.search(r'\.idProduct\s*=\s*USB_PID\s*[,;]', text):
+            pids.setdefault(base, []).append(str(rel))
+
+    dups = {pid: users for pid, users in pids.items() if len(users) > 1}
+    for pid, users in sorted(dups.items()):
+        print(f'duplicate USB PID 0x{pid:04x}:', file=sys.stderr)
+        for u in users:
+            print(f'  {u}', file=sys.stderr)
+    if dups:
+        return 1
+    print(f'{len(pids)} unique example USB PIDs')
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())