comparator.py - find shared functions between pokered/pokecrystal

extras/comparator.py

@@ -0,0 +1,228 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+# author: Bryan Bishop <kanzure@gmail.com>
+# date: 2012-05-29
+# purpose: find shared functions between red/crystal
+
+from crystal import get_label_from_line,           \
+                    get_address_from_line_comment, \
+                    AsmSection
+
+from romstr import RomStr, AsmList
+
+def load_rom(path):
+    """ Loads a ROM file into an abbreviated RomStr object.
+    """
+
+    fh = open(path, "r")
+    x  = RomStr(fh.read())
+    fh.close()
+
+    return x
+
+def load_asm(path):
+    """ Loads source ASM into an abbreviated AsmList object.
+    """
+
+    fh = open(path, "r")
+    x = AsmList(fh.read().split("\n"))
+    fh.close()
+
+    return x
+
+def findall_iter(sub, string):
+    # url: http://stackoverflow.com/a/3874760/687783
+
+    def next_index(length):
+        index = 0 - length
+        while True:
+            index = string.find(sub, index + length)
+            yield index
+
+    return iter(next_index(len(sub)).next, -1)
+
+class Address(int):
+    """ A simple int wrapper to take 0xFFFF and $FFFF addresses.
+    """
+
+    def __new__(cls, x=None, *args, **kwargs):
+        if type(x) == str:
+            if "$" in x:
+                x = x.replace("$", "0x")
+
+            if "0x" in str:
+                instance = int.__new__(cls, int(x, base=16), *args, **kwargs)
+            else:
+                msg = "Address.__new__ doesn't know how to parse this string"
+                raise Exception, msg
+        else:
+            instance = int.__new__(cls, x, *args, **kwargs)
+
+        return instance
+
+found_blobs = []
+
+class BinaryBlob(object):
+    """ Stores a label, line number, and addresses of a function from Pokémon
+    Red. These details can be used to determine whether or not the function was
+    copied into Pokémon Crystal.
+    """
+
+    start_address = None
+    end_address   = None
+    label         = None
+    line_number   = None
+    bytes         = None
+    bank          = None
+    debug         = False
+    locations     = None
+
+    def __init__(self, start_address=None, end_address=None, label=None, \
+                 debug=None, line_number=None):
+        if not isinstance(start_address, Address):
+            start_address = Address(start_address)
+        if not isinstance(end_address, Address):
+            end_address   = Address(end_address)
+
+        assert label != None,          "label can't be none"
+        assert isinstance(label, str), "label must be a string"
+        assert line_number != None,    "line_number must be provided"
+
+        self.start_address = start_address
+        self.end_address   = end_address
+        self.label         = label
+        self.line_number   = line_number
+        self.bytes         = []
+        self.locations     = []
+        self.bank          = start_address / 0x4000
+
+        if debug != None:
+            self.debug = debug
+
+        self.parse_from_red()
+        self.find_in_crystal()
+
+    def __repr__(self):
+        """ A beautiful poem.
+        """
+
+        r = "BinaryBlob("
+        r += "label=\""+self.label+"\", "
+        r += "start_address="+hex(self.start_address)+", "
+        r += "size="+str(self.end_address - self.start_address)+", "
+        r += "located="+str(len(self.locations) > 0)
+        r += ")"
+
+        return r
+
+    def __str__(self):
+        return self.__repr__()
+
+    def parse_from_red(self):
+        """ Reads bytes from Pokémon Red and stores them.
+        """
+
+        self.bytes = redrom[self.start_address : self.end_address + 1]
+
+    def pretty_bytes(self):
+        """ Returns a better looking range of bytes.
+        """
+
+        bytes = redrom.interval(self.start_address,    \
+                self.end_address - self.start_address, \
+                strings=False, debug=True)
+
+        return bytes
+
+    def find_in_crystal(self):
+        """ Checks whether or not the bytes appear in Pokémon Crystal.
+        """
+
+        finditer       = findall_iter(self.bytes, cryrom)
+        self.locations = [match for match in finditer]
+
+        if len(self.locations) > 0:
+            found_blobs.append(self)
+
+            if self.debug:
+                print self.label + ": found " + str(len(self.locations)) + " matches."
+
+pokecrystal_rom_path = "../baserom.gbc"
+pokecrystal_src_path = "../main.asm"
+pokered_rom_path     = "../pokered-baserom.gbc"
+pokered_src_path     = "../pokered-main.asm"
+
+cryrom           = load_rom(pokecrystal_rom_path)
+crysrc           = load_asm(pokecrystal_src_path)
+redrom           = load_rom(pokered_rom_path)
+redsrc           = load_asm(pokered_src_path)
+
+def scan_red_asm(bank_stop=3, debug=True):
+    """ Scans the ASM from Pokémon Red. Finds labels and objects. Does things.
+
+    Uses get_label_from_line and get_address_from_line_comment.
+    """
+
+    # whether or not to show the lines from redsrc
+    show_lines            = False
+
+    line_number           = 0
+    current_bank          = 0
+
+    current_label         = None
+    latest_label          = None
+    current_start_address = None
+    latest_start_address  = None
+    latest_line           = ""
+
+    for line in redsrc:
+        if debug and show_lines:
+            print "processing a line from red: " + line
+
+        if line[0:7] == "SECTION":
+            thing        = AsmSection(line)
+            current_bank = thing.bank_id
+
+            if debug:
+                print "scan_red_asm: switching to bank " + str(current_bank)
+
+        elif line[0:6] != "INCBIN":
+            if ":" in line:
+                current_label         = get_label_from_line(line)
+                current_start_address = get_address_from_line_comment(line, \
+                                        bank=current_bank)
+
+                if current_label != None and current_start_address != None and \
+                   current_start_address != 0 and current_start_address != latest_start_address:
+                    if latest_label != None:
+                        if latest_label not in ["Char52", "PokeCenterSignText", "DefaultNamesPlayer", "Unnamed_6a12"]:
+                            blob = BinaryBlob(label=latest_label,      \
+                                   start_address=latest_start_address, \
+                                   end_address=current_start_address,  \
+                                   line_number=line_number)
+
+                            if debug:
+                                print "Created a new blob: " + str(blob) + " from line: " + str(latest_line)
+
+                    latest_label          = current_label
+                    latest_start_address  = current_start_address
+                    latest_line           = line
+
+        line_number += 1
+
+        if current_bank == bank_stop:
+            if debug:
+                print "scan_red_asm: stopping because current_bank >= " + \
+                      str(bank_stop) + " (bank_stop)"
+
+            break
+
+scan_red_asm()
+
+print "================================"
+
+for blob in found_blobs:
+    print blob
+
+print "Found " + str(len(found_blobs)) + " possibly copied functions."
+