From 294da9e355b71a80987cf3b85388eadd5e94b8e7 Mon Sep 17 00:00:00 2001
From: cadmic <cadmic24@gmail.com>
Date: Sat, 27 Jul 2024 19:29:15 -0700
Subject: [PATCH] Detect shifted .bss sections in check_ordering.py (#1992)

* Restrict check_ordering.py to .bss sections by default

* Detect shifted .bss sections in check_ordering.py
---
 tools/check_ordering.py | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/tools/check_ordering.py b/tools/check_ordering.py
index 83eecfacb4..0af2d9a949 100755
--- a/tools/check_ordering.py
+++ b/tools/check_ordering.py
@@ -94,7 +94,7 @@ def read_s16(f: BinaryIO, offset: int) -> int:
 
 def main():
     parser = argparse.ArgumentParser(
-        description="Report data/bss reorderings between the baserom and the current build "
+        description="Report bss reorderings between the baserom and the current build "
         "by parsing relocations from the built object files and comparing their final values "
         "between the baserom and the current build. "
         "Assumes that the only differences are due to ordering and that the text sections of the "
@@ -112,6 +112,11 @@ def main():
         type=str,
         help="ROM segment to check, e.g. 'boot', 'code', or 'ovl_player_actor' (default: all)",
     )
+    parser.add_argument(
+        "--all-sections",
+        action="store_true",
+        help="Check ordering for all section types, not just .bss",
+    )
 
     args = parser.parse_args()
     version = args.oot_version
@@ -176,10 +181,9 @@ def main():
                 else:
                     assert False, "Invalid relocation"
 
-                if base_value != build_value:
-                    pointers.append(
-                        Pointer(reloc.name, reloc.addend, base_value, build_value)
-                    )
+                pointers.append(
+                    Pointer(reloc.name, reloc.addend, base_value, build_value)
+                )
 
     # Remove duplicates and sort by baserom address
     pointers = list({p.base_value: p for p in pointers}.values())
@@ -188,6 +192,9 @@ def main():
     # Go through sections and report differences
     for mapfile_segment in source_code_segments:
         for file in mapfile_segment:
+            if not args.all_sections and not file.sectionType == ".bss":
+                continue
+
             pointers_in_section = [
                 p
                 for p in pointers
@@ -196,6 +203,17 @@ def main():
             if not pointers_in_section:
                 continue
 
+            # Try to detect if the section is shifted by comparing the lowest
+            # address among any pointer into the section between base and build
+            base_min_address = min(p.base_value for p in pointers_in_section)
+            build_min_address = min(p.build_value for p in pointers_in_section)
+            section_shift = build_min_address - base_min_address
+            if all(
+                p.build_value == p.base_value + section_shift
+                for p in pointers_in_section
+            ):
+                continue
+
             print(f"{file.filepath} {file.sectionType} is reordered:")
             for i, p in enumerate(pointers_in_section):
                 if p.addend > 0: