Add new script to compare the stack layout (#1112)

* Add new script to debug the stack layout

* fix small error in script

---------

Co-authored-by: jonschz <jonschz@users.noreply.github.com>

tools/isledecomp/isledecomp/compare/core.py

@@ -15,7 +15,7 @@ from isledecomp.types import SymbolType
 from isledecomp.compare.asm import ParseAsm
 from isledecomp.compare.asm.fixes import assert_fixup, find_effective_match
 from .db import CompareDb, MatchInfo
-from .diff import combined_diff
+from .diff import combined_diff, CombinedDiffOutput
 from .lines import LinesDb
 
 
@@ -29,7 +29,7 @@ class DiffReport:
     orig_addr: int
     recomp_addr: int
     name: str
-    udiff: Optional[List[str]] = None
+    udiff: Optional[CombinedDiffOutput] = None
     ratio: float = 0.0
     is_effective_match: bool = False
     is_stub: bool = False

tools/isledecomp/isledecomp/compare/diff.py

@@ -2,7 +2,13 @@ from difflib import SequenceMatcher
 from typing import Dict, List, Tuple
 
 CombinedDiffInput = List[Tuple[str, str]]
-CombinedDiffOutput = List[Tuple[str, List[Dict[str, Tuple[str, str]]]]]
+# from inner to outer:
+# Tuple[str, ...]: either (orig_addr, instruction, recomp_addr) or (addr, instruction)
+# List[...]: a contiguous block of instructions, all matching or all mismatching
+# Dict[...]: either {"both": List[...]} or {"orig": [...], "recomp": [...]}
+# Tuple[str, List[...]]: One contiguous part of the diff (without skipping matching code)
+# List[...]: The list of all the contiguous diffs of a given function
+CombinedDiffOutput = List[Tuple[str, List[Dict[str, List[Tuple[str, ...]]]]]]
 
 
 def combined_diff(