reccmp: vtable comparison (#452)

* Add vtable comparison to reccmp

* Add missing scalar deleting destructors

* Fix some vtables

---------

Co-authored-by: Christian Semmler <mail@csemmler.com>

tools/isledecomp/isledecomp/compare/core.py

@@ -1,6 +1,7 @@
 import os
 import logging
 import difflib
+import struct
 from dataclasses import dataclass
 from typing import Iterable, List, Optional
 from isledecomp.cvdump.demangler import demangle_string_const
@@ -18,6 +19,7 @@ logger = logging.getLogger(__name__)
 
 @dataclass
 class DiffReport:
+    match_type: SymbolType
     orig_addr: int
     recomp_addr: int
     name: str
@@ -214,17 +216,11 @@ class Compare:
                 # function in the first place.
                 self._db.skip_compare(thunk_from_orig)
 
-    def get_one_function(self, addr: int) -> Optional[MatchInfo]:
-        """i.e. verbose mode for reccmp"""
-        return self._db.get_one_function(addr)
-
-    def get_functions(self) -> List[MatchInfo]:
-        return self._db.get_matches(SymbolType.FUNCTION)
-
     def _compare_function(self, match: MatchInfo) -> DiffReport:
         if match.size == 0:
             # Report a failed match to make the user aware of the empty function.
             return DiffReport(
+                match_type=SymbolType.FUNCTION,
                 orig_addr=match.orig_addr,
                 recomp_addr=match.recomp_addr,
                 name=match.name,
@@ -281,6 +277,7 @@ class Compare:
             unified_diff = []
 
         return DiffReport(
+            match_type=SymbolType.FUNCTION,
             orig_addr=match.orig_addr,
             recomp_addr=match.recomp_addr,
             name=match.name,
@@ -289,16 +286,121 @@ class Compare:
             is_effective_match=is_effective_match,
         )
 
-    def compare_function(self, addr: int) -> Optional[DiffReport]:
-        match = self.get_one_function(addr)
+    def _compare_vtable(self, match: MatchInfo) -> DiffReport:
+        vtable_size = match.size
+
+        # The vtable size should always be a multiple of 4 because that
+        # is the pointer size. If it is not (for whatever reason)
+        # it would cause iter_unpack to blow up so let's just fix it.
+        if vtable_size % 4 != 0:
+            logger.warning(
+                "Vtable for class %s has irregular size %d", match.name, vtable_size
+            )
+            vtable_size = 4 * (vtable_size // 4)
+
+        orig_table = self.orig_bin.read(match.orig_addr, vtable_size)
+        recomp_table = self.recomp_bin.read(match.recomp_addr, vtable_size)
+
+        raw_addrs = zip(
+            [t for (t,) in struct.iter_unpack("<L", orig_table)],
+            [t for (t,) in struct.iter_unpack("<L", recomp_table)],
+        )
+
+        def match_text(
+            i: int, m: Optional[MatchInfo], raw_addr: Optional[int] = None
+        ) -> str:
+            """Format the function reference at this vtable index as text.
+            If we have not identified this function, we have the option to
+            display the raw address. This is only worth doing for the original addr
+            because we should always be able to identify the recomp function.
+            If the original function is missing then this probably means that the class
+            should override the given function from the superclass, but we have not
+            implemented this yet.
+            """
+            index = f"vtable0x{i*4:02x}"
+
+            if m is not None:
+                orig = hex(m.orig_addr) if m.orig_addr is not None else "no orig"
+                recomp = (
+                    hex(m.recomp_addr) if m.recomp_addr is not None else "no recomp"
+                )
+                return f"{index:>12}  :  ({orig:10} / {recomp:10})  :  {m.name}"
+
+            if raw_addr is not None:
+                return f"{index:>12}  :  0x{raw_addr:x} from orig not annotated."
+
+            return f"{index:>12}  :  (no match)"
+
+        orig_text = []
+        recomp_text = []
+        ratio = 0
+        n_entries = 0
+
+        # Now compare each pointer from the two vtables.
+        for i, (raw_orig, raw_recomp) in enumerate(raw_addrs):
+            orig = self._db.get_by_orig(raw_orig)
+            recomp = self._db.get_by_recomp(raw_recomp)
+
+            if (
+                orig is not None
+                and recomp is not None
+                and orig.recomp_addr == recomp.recomp_addr
+            ):
+                ratio += 1
+
+            n_entries += 1
+            orig_text.append(match_text(i, orig, raw_orig))
+            recomp_text.append(match_text(i, recomp))
+
+        ratio = ratio / float(n_entries) if n_entries > 0 else 0
+
+        # n=100: Show the entire table if there is a diff to display.
+        # Otherwise it would be confusing if the table got cut off.
+        unified_diff = difflib.unified_diff(orig_text, recomp_text, n=100)
+
+        return DiffReport(
+            match_type=SymbolType.VTABLE,
+            orig_addr=match.orig_addr,
+            recomp_addr=match.recomp_addr,
+            name=f"{match.name}::`vftable'",
+            udiff=unified_diff,
+            ratio=ratio,
+        )
+
+    def _compare_match(self, match: MatchInfo) -> Optional[DiffReport]:
+        """Router for comparison type"""
+        if match.compare_type == SymbolType.FUNCTION:
+            return self._compare_function(match)
+
+        if match.compare_type == SymbolType.VTABLE:
+            return self._compare_vtable(match)
+
+        return None
+
+    ## Public API
+
+    def get_functions(self) -> List[MatchInfo]:
+        return self._db.get_matches_by_type(SymbolType.FUNCTION)
+
+    def get_vtables(self) -> List[MatchInfo]:
+        return self._db.get_matches_by_type(SymbolType.VTABLE)
+
+    def compare_address(self, addr: int) -> Optional[DiffReport]:
+        match = self._db.get_one_match(addr)
         if match is None:
             return None
 
-        return self._compare_function(match)
+        return self._compare_match(match)
+
+    def compare_all(self) -> Iterable[DiffReport]:
+        for match in self._db.get_matches():
+            diff = self._compare_match(match)
+            if diff is not None:
+                yield diff
 
     def compare_functions(self) -> Iterable[DiffReport]:
         for match in self.get_functions():
-            yield self._compare_function(match)
+            yield self._compare_match(match)
 
     def compare_variables(self):
         pass
@@ -309,5 +411,6 @@ class Compare:
     def compare_strings(self):
         pass
 
-    def compare_vtables(self):
-        pass
+    def compare_vtables(self) -> Iterable[DiffReport]:
+        for match in self.get_vtables():
+            yield self._compare_match(match)

tools/isledecomp/isledecomp/compare/db.py

@@ -82,17 +82,29 @@ class CompareDb:
 
         return [string for (string,) in cur.fetchall()]
 
-    def get_one_function(self, addr: int) -> Optional[MatchInfo]:
+    def get_matches(self) -> Optional[MatchInfo]:
         cur = self._db.execute(
             """SELECT compare_type, orig_addr, recomp_addr, name, size
             FROM `symbols`
-            WHERE compare_type = ?
-            AND orig_addr = ?
+            WHERE orig_addr IS NOT NULL
             AND recomp_addr IS NOT NULL
             AND should_skip IS FALSE
             ORDER BY orig_addr
             """,
-            (SymbolType.FUNCTION.value, addr),
+        )
+        cur.row_factory = matchinfo_factory
+
+        return cur.fetchall()
+
+    def get_one_match(self, addr: int) -> Optional[MatchInfo]:
+        cur = self._db.execute(
+            """SELECT compare_type, orig_addr, recomp_addr, name, size
+            FROM `symbols`
+            WHERE orig_addr = ?
+            AND recomp_addr IS NOT NULL
+            AND should_skip IS FALSE
+            """,
+            (addr,),
         )
         cur.row_factory = matchinfo_factory
         return cur.fetchone()
@@ -119,7 +131,7 @@ class CompareDb:
         cur.row_factory = matchinfo_factory
         return cur.fetchone()
 
-    def get_matches(self, compare_type: SymbolType) -> List[MatchInfo]:
+    def get_matches_by_type(self, compare_type: SymbolType) -> List[MatchInfo]:
         cur = self._db.execute(
             """SELECT compare_type, orig_addr, recomp_addr, name, size
             FROM `symbols`