#!/usr/bin/env python3 # PYTHON_ARGCOMPLETE_OK import argparse import sys from typing import ( Any, Dict, List, Match, NamedTuple, NoReturn, Optional, Set, Tuple, Union, Callable, Pattern, ) def fail(msg: str) -> NoReturn: print(msg, file=sys.stderr) sys.exit(1) # Prefer to use diff_settings.py from the current working directory sys.path.insert(0, ".") try: import diff_settings except ModuleNotFoundError: fail("Unable to find diff_settings.py in the same directory.") sys.path.pop(0) # ==== COMMAND-LINE ==== try: import argcomplete # type: ignore except ModuleNotFoundError: argcomplete = None parser = argparse.ArgumentParser(description="Diff MIPS or AArch64 assembly.") start_argument = parser.add_argument( "start", help="Function name or address to start diffing from.", ) if argcomplete: def complete_symbol( prefix: str, parsed_args: argparse.Namespace, **kwargs: object ) -> List[str]: if not prefix or prefix.startswith("-"): # skip reading the map file, which would # result in a lot of useless completions return [] config: Dict[str, Any] = {} diff_settings.apply(config, parsed_args) # type: ignore mapfile = config.get("mapfile") if not mapfile: return [] completes = [] with open(mapfile) as f: data = f.read() # assume symbols are prefixed by a space character search = f" {prefix}" pos = data.find(search) while pos != -1: # skip the space character in the search string pos += 1 # assume symbols are suffixed by either a space # character or a (unix-style) line return spacePos = data.find(" ", pos) lineReturnPos = data.find("\n", pos) if lineReturnPos == -1: endPos = spacePos elif spacePos == -1: endPos = lineReturnPos else: endPos = min(spacePos, lineReturnPos) if endPos == -1: match = data[pos:] pos = -1 else: match = data[pos:endPos] pos = data.find(search, endPos) completes.append(match) return completes setattr(start_argument, "completer", complete_symbol) parser.add_argument( "end", nargs="?", help="Address to end diff at.", ) parser.add_argument( "-o", dest="diff_obj", action="store_true", help="Diff .o files rather than a whole binary. This makes it possible to " "see symbol names. (Recommended)", ) parser.add_argument( "-e", "--elf", dest="diff_elf_symbol", metavar="SYMBOL", help="Diff a given function in two ELFs, one being stripped and the other " "one non-stripped. Requires objdump from binutils 2.33+.", ) parser.add_argument( "--source", action="store_true", help="Show source code (if possible). Only works with -o and -e.", ) parser.add_argument( "--inlines", action="store_true", help="Show inline function calls (if possible). Only works with -o and -e.", ) parser.add_argument( "--base-asm", dest="base_asm", metavar="FILE", help="Read assembly from given file instead of configured base img.", ) parser.add_argument( "--write-asm", dest="write_asm", metavar="FILE", help="Write the current assembly output to file, e.g. for use with --base-asm.", ) parser.add_argument( "-m", "--make", dest="make", action="store_true", help="Automatically run 'make' on the .o file or binary before diffing.", ) parser.add_argument( "-l", "--skip-lines", dest="skip_lines", type=int, default=0, metavar="LINES", help="Skip the first N lines of output.", ) parser.add_argument( "-s", "--stop-jr-ra", dest="stop_jrra", action="store_true", help="Stop disassembling at the first 'jr ra'. Some functions have multiple return points, so use with care!", ) parser.add_argument( "-i", "--ignore-large-imms", dest="ignore_large_imms", action="store_true", help="Pretend all large enough immediates are the same.", ) parser.add_argument( "-I", "--ignore-addr-diffs", action="store_true", help="Ignore address differences. Currently only affects AArch64.", ) parser.add_argument( "-B", "--no-show-branches", dest="show_branches", action="store_false", help="Don't visualize branches/branch targets.", ) parser.add_argument( "-S", "--base-shift", dest="base_shift", type=str, default="0", help="Diff position X in our img against position X + shift in the base img. " 'Arithmetic is allowed, so e.g. |-S "0x1234 - 0x4321"| is a reasonable ' "flag to pass if it is known that position 0x1234 in the base img syncs " "up with position 0x4321 in our img. Not supported together with -o.", ) parser.add_argument( "-w", "--watch", dest="watch", action="store_true", help="Automatically update when source/object files change. " "Recommended in combination with -m.", ) parser.add_argument( "-3", "--threeway=prev", dest="threeway", action="store_const", const="prev", help="Show a three-way diff between target asm, current asm, and asm " "prior to -w rebuild. Requires -w.", ) parser.add_argument( "-b", "--threeway=base", dest="threeway", action="store_const", const="base", help="Show a three-way diff between target asm, current asm, and asm " "when diff.py was started. Requires -w.", ) parser.add_argument( "--width", dest="column_width", type=int, default=50, help="Sets the width of the left and right view column.", ) parser.add_argument( "--algorithm", dest="algorithm", default="levenshtein", choices=["levenshtein", "difflib"], help="Diff algorithm to use. Levenshtein gives the minimum diff, while difflib " "aims for long sections of equal opcodes. Defaults to %(default)s.", ) parser.add_argument( "--max-size", "--max-lines", dest="max_lines", type=int, default=1024, help="The maximum length of the diff, in lines.", ) # Project-specific flags, e.g. different versions/make arguments. add_custom_arguments_fn = getattr(diff_settings, "add_custom_arguments", None) if add_custom_arguments_fn: add_custom_arguments_fn(parser) if argcomplete: argcomplete.autocomplete(parser) # ==== IMPORTS ==== # (We do imports late to optimize auto-complete performance.) import re import os import ast import subprocess import difflib import string import itertools import threading import queue import time MISSING_PREREQUISITES = ( "Missing prerequisite python module {}. " "Run `python3 -m pip install --user colorama ansiwrap watchdog python-Levenshtein cxxfilt` to install prerequisites (cxxfilt only needed with --source)." ) try: from colorama import Fore, Style, Back # type: ignore import ansiwrap # type: ignore import watchdog # type: ignore except ModuleNotFoundError as e: fail(MISSING_PREREQUISITES.format(e.name)) # ==== CONFIG ==== args = parser.parse_args() # Set imgs, map file and make flags in a project-specific manner. config: Dict[str, Any] = {} diff_settings.apply(config, args) # type: ignore arch: str = config.get("arch", "mips") baseimg: Optional[str] = config.get("baseimg") myimg: Optional[str] = config.get("myimg") mapfile: Optional[str] = config.get("mapfile") build_command: List[str] = config.get("make_command", ["make", *config.get("makeflags", [])]) source_directories: Optional[List[str]] = config.get("source_directories") objdump_executable: Optional[str] = config.get("objdump_executable") map_format: str = config.get("map_format", "gnu") mw_build_dir: str = config.get("mw_build_dir", "build/") MAX_FUNCTION_SIZE_LINES: int = args.max_lines MAX_FUNCTION_SIZE_BYTES: int = MAX_FUNCTION_SIZE_LINES * 4 COLOR_ROTATION: List[str] = [ Fore.MAGENTA, Fore.CYAN, Fore.GREEN, Fore.RED, Fore.LIGHTYELLOW_EX, Fore.LIGHTMAGENTA_EX, Fore.LIGHTCYAN_EX, Fore.LIGHTGREEN_EX, Fore.LIGHTBLACK_EX, ] BUFFER_CMD: List[str] = ["tail", "-c", str(10 ** 9)] LESS_CMD: List[str] = ["less", "-SRic", "-#6"] DEBOUNCE_DELAY: float = 0.1 FS_WATCH_EXTENSIONS: List[str] = [".c", ".h"] # ==== LOGIC ==== ObjdumpCommand = Tuple[List[str], str, Optional[str]] if args.algorithm == "levenshtein": try: import Levenshtein # type: ignore except ModuleNotFoundError as e: fail(MISSING_PREREQUISITES.format(e.name)) if args.source: try: import cxxfilt # type: ignore except ModuleNotFoundError as e: fail(MISSING_PREREQUISITES.format(e.name)) if args.threeway and not args.watch: fail("Threeway diffing requires -w.") if objdump_executable is None: for objdump_cand in ["mips-linux-gnu-objdump", "mips64-elf-objdump"]: try: subprocess.check_call( [objdump_cand, "--version"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, ) objdump_executable = objdump_cand break except subprocess.CalledProcessError: pass except FileNotFoundError: pass if not objdump_executable: fail( "Missing binutils; please ensure mips-linux-gnu-objdump or mips64-elf-objdump exist, or configure objdump_executable." ) def maybe_eval_int(expr: str) -> Optional[int]: try: ret = ast.literal_eval(expr) if not isinstance(ret, int): raise Exception("not an integer") return ret except Exception: return None def eval_int(expr: str, emsg: str) -> int: ret = maybe_eval_int(expr) if ret is None: fail(emsg) return ret def eval_line_num(expr: str) -> int: return int(expr.strip().replace(":", ""), 16) def run_make(target: str) -> None: subprocess.check_call(build_command + [target]) def run_make_capture_output(target: str) -> "subprocess.CompletedProcess[bytes]": return subprocess.run( build_command + [target], stderr=subprocess.PIPE, stdout=subprocess.PIPE, ) def restrict_to_function(dump: str, fn_name: str) -> str: out: List[str] = [] search = f"<{fn_name}>:" found = False for line in dump.split("\n"): if found: if len(out) >= MAX_FUNCTION_SIZE_LINES: break out.append(line) elif search in line: found = True return "\n".join(out) def maybe_get_objdump_source_flags() -> List[str]: if not args.source: return [] flags = [ "--source", "--source-comment=│ ", "-l", ] if args.inlines: flags.append("--inlines") return flags def run_objdump(cmd: ObjdumpCommand) -> str: flags, target, restrict = cmd assert objdump_executable, "checked previously" out = subprocess.check_output( [objdump_executable] + arch_flags + flags + [target], universal_newlines=True ) if restrict is not None: return restrict_to_function(out, restrict) return out base_shift: int = eval_int( args.base_shift, "Failed to parse --base-shift (-S) argument as an integer." ) def search_map_file(fn_name: str) -> Tuple[Optional[str], Optional[int]]: if not mapfile: fail(f"No map file configured; cannot find function {fn_name}.") try: with open(mapfile) as f: contents = f.read() except Exception: fail(f"Failed to open map file {mapfile} for reading.") if map_format == 'gnu': lines = contents.split("\n") try: cur_objfile = None ram_to_rom = None cands = [] last_line = "" for line in lines: if line.startswith(" .text"): cur_objfile = line.split()[3] if "load address" in line: tokens = last_line.split() + line.split() ram = int(tokens[1], 0) rom = int(tokens[5], 0) ram_to_rom = rom - ram if line.endswith(" " + fn_name): ram = int(line.split()[0], 0) if cur_objfile is not None and ram_to_rom is not None: cands.append((cur_objfile, ram + ram_to_rom)) last_line = line except Exception as e: import traceback traceback.print_exc() fail(f"Internal error while parsing map file") if len(cands) > 1: fail(f"Found multiple occurrences of function {fn_name} in map file.") if len(cands) == 1: return cands[0] elif map_format == 'mw': # ram elf rom object name find = re.findall(re.compile(r' \S+ \S+ (\S+) (\S+) . ' + fn_name + r'(?: \(entry of \.(?:init|text)\))? \t(\S+)'), contents) if len(find) > 1: fail(f"Found multiple occurrences of function {fn_name} in map file.") if len(find) == 1: rom = int(find[0][1],16) objname = find[0][2] # The metrowerks linker map format does not contain the full object path, so we must complete it manually. objfiles = [os.path.join(dirpath, f) for dirpath, _, filenames in os.walk(mw_build_dir) for f in filenames if f == objname] if len(objfiles) > 1: all_objects = "\n".join(objfiles) fail(f"Found multiple objects of the same name {objname} in {mw_build_dir}, cannot determine which to diff against: \n{all_objects}") if len(objfiles) == 1: objfile = objfiles[0] # TODO Currently the ram-rom conversion only works for diffing ELF executables, but it would likely be more convenient to diff DOLs. # At this time it is recommended to always use -o when running the diff script as this mode does not make use of the ram-rom conversion return objfile, rom else: fail(f"Linker map format {map_format} unrecognised.") return None, None def dump_elf() -> Tuple[str, ObjdumpCommand, ObjdumpCommand]: if not baseimg or not myimg: fail("Missing myimg/baseimg in config.") if base_shift: fail("--base-shift not compatible with -e") start_addr = eval_int(args.start, "Start address must be an integer expression.") if args.end is not None: end_addr = eval_int(args.end, "End address must be an integer expression.") else: end_addr = start_addr + MAX_FUNCTION_SIZE_BYTES flags1 = [ f"--start-address={start_addr}", f"--stop-address={end_addr}", ] flags2 = [ f"--disassemble={args.diff_elf_symbol}", ] objdump_flags = ["-drz", "-j", ".text"] return ( myimg, (objdump_flags + flags1, baseimg, None), (objdump_flags + flags2 + maybe_get_objdump_source_flags(), myimg, None), ) def dump_objfile() -> Tuple[str, ObjdumpCommand, ObjdumpCommand]: if base_shift: fail("--base-shift not compatible with -o") if args.end is not None: fail("end address not supported together with -o") if args.start.startswith("0"): fail("numerical start address not supported with -o; pass a function name") objfile, _ = search_map_file(args.start) if not objfile: fail("Not able to find .o file for function.") if args.make: run_make(objfile) if not os.path.isfile(objfile): fail(f"Not able to find .o file for function: {objfile} is not a file.") refobjfile = "expected/" + objfile if not os.path.isfile(refobjfile): fail(f'Please ensure an OK .o file exists at "{refobjfile}".') objdump_flags = ["-Drz"] return ( objfile, (objdump_flags, refobjfile, args.start), (objdump_flags + maybe_get_objdump_source_flags(), objfile, args.start), ) def dump_binary() -> Tuple[str, ObjdumpCommand, ObjdumpCommand]: if not baseimg or not myimg: fail("Missing myimg/baseimg in config.") if args.make: run_make(myimg) start_addr = maybe_eval_int(args.start) if start_addr is None: _, start_addr = search_map_file(args.start) if start_addr is None: fail("Not able to find function in map file.") if args.end is not None: end_addr = eval_int(args.end, "End address must be an integer expression.") else: end_addr = start_addr + MAX_FUNCTION_SIZE_BYTES objdump_flags = ["-Dz", "-bbinary", "-EB"] flags1 = [ f"--start-address={start_addr + base_shift}", f"--stop-address={end_addr + base_shift}", ] flags2 = [f"--start-address={start_addr}", f"--stop-address={end_addr}"] return ( myimg, (objdump_flags + flags1, baseimg, None), (objdump_flags + flags2, myimg, None), ) def ansi_ljust(s: str, width: int) -> str: """Like s.ljust(width), but accounting for ANSI colors.""" needed: int = width - ansiwrap.ansilen(s) if needed > 0: return s + " " * needed else: return s if arch == "mips": re_int = re.compile(r"[0-9]+") re_comment = re.compile(r"<.*?>") re_reg = re.compile( r"\$?\b(a[0-3]|t[0-9]|s[0-8]|at|v[01]|f[12]?[0-9]|f3[01]|k[01]|fp|ra|zero)\b" ) re_sprel = re.compile(r"(?<=,)([0-9]+|0x[0-9a-f]+)\(sp\)") re_large_imm = re.compile(r"-?[1-9][0-9]{2,}|-?0x[0-9a-f]{3,}") re_imm = re.compile(r"(\b|-)([0-9]+|0x[0-9a-fA-F]+)\b(?!\(sp)|%(lo|hi)\([^)]*\)") forbidden = set(string.ascii_letters + "_") arch_flags = ["-m", "mips:4300"] branch_likely_instructions = { "beql", "bnel", "beqzl", "bnezl", "bgezl", "bgtzl", "blezl", "bltzl", "bc1tl", "bc1fl", } branch_instructions = branch_likely_instructions.union( { "b", "beq", "bne", "beqz", "bnez", "bgez", "bgtz", "blez", "bltz", "bc1t", "bc1f", } ) instructions_with_address_immediates = branch_instructions.union({"jal", "j"}) elif arch == "aarch64": re_int = re.compile(r"[0-9]+") re_comment = re.compile(r"(<.*?>|//.*$)") # GPRs and FP registers: X0-X30, W0-W30, [DSHQ]0..31 # The zero registers and SP should not be in this list. re_reg = re.compile(r"\$?\b([dshq][12]?[0-9]|[dshq]3[01]|[xw][12]?[0-9]|[xw]30)\b") re_sprel = re.compile(r"sp, #-?(0x[0-9a-fA-F]+|[0-9]+)\b") re_large_imm = re.compile(r"-?[1-9][0-9]{2,}|-?0x[0-9a-f]{3,}") re_imm = re.compile(r"(?|//.*$)") re_reg = re.compile(r"\$?\b([rf][0-9]+)\b") re_sprel = re.compile(r"(?<=,)(-?[0-9]+|-?0x[0-9a-f]+)\(r1\)") re_large_imm = re.compile(r"-?[1-9][0-9]{2,}|-?0x[0-9a-f]{3,}") re_imm = re.compile(r"(\b|-)([0-9]+|0x[0-9a-fA-F]+)\b(?!\(r1)|[^@]*@(ha|h|lo)") arch_flags = [] forbidden = set(string.ascii_letters + "_") branch_likely_instructions = set() branch_instructions = { "b", "beq", "beq+", "beq-", "bne", "bne+", "bne-", "blt", "blt+", "blt-", "ble", "ble+", "ble-", "bdnz", "bdnz+", "bdnz-", "bge", "bge+", "bge-", "bgt", "bgt+", "bgt-", } instructions_with_address_immediates = branch_instructions.union({"bl"}) else: fail(f"Unknown architecture: {arch}") def hexify_int(row: str, pat: Match[str]) -> str: full = pat.group(0) if len(full) <= 1: # leave one-digit ints alone return full start, end = pat.span() if start and row[start - 1] in forbidden: return full if end < len(row) and row[end] in forbidden: return full return hex(int(full)) def parse_relocated_line(line: str) -> Tuple[str, str, str]: try: ind2 = line.rindex(",") except ValueError: try: ind2 = line.rindex("\t") except ValueError: ind2 = line.rindex(" ") before = line[: ind2 + 1] after = line[ind2 + 1 :] ind2 = after.find("(") if ind2 == -1: imm, after = after, "" else: imm, after = after[:ind2], after[ind2:] if imm == "0x0": imm = "0" return before, imm, after def process_mips_reloc(row: str, prev: str) -> str: before, imm, after = parse_relocated_line(prev) repl = row.split()[-1] if imm != "0": # MIPS uses relocations with addends embedded in the code as immediates. # If there is an immediate, show it as part of the relocation. Ideally # we'd show this addend in both %lo/%hi, but annoyingly objdump's output # doesn't include enough information to pair up %lo's and %hi's... # TODO: handle unambiguous cases where all addends for a symbol are the # same, or show "+???". mnemonic = prev.split()[0] if mnemonic in instructions_with_address_immediates and not imm.startswith("0x"): imm = "0x" + imm repl += "+" + imm if int(imm, 0) > 0 else imm if "R_MIPS_LO16" in row: repl = f"%lo({repl})" elif "R_MIPS_HI16" in row: # Ideally we'd pair up R_MIPS_LO16 and R_MIPS_HI16 to generate a # correct addend for each, but objdump doesn't give us the order of # the relocations, so we can't find the right LO16. :( repl = f"%hi({repl})" elif "R_MIPS_26" in row: # Function calls pass elif "R_MIPS_PC16" in row: # Branch to glabel. This gives confusing output, but there's not much # we can do here. pass else: assert False, f"unknown relocation type '{row}' for line '{prev}'" return before + repl + after def process_ppc_reloc(row: str, prev: str) -> str: assert any(r in row for r in ["R_PPC_REL24", "R_PPC_ADDR16", "R_PPC_EMB_SDA21"]), f"unknown relocation type '{row}' for line '{prev}'" before, imm, after = parse_relocated_line(prev) repl = row.split()[-1] if "R_PPC_REL24" in row: # function calls pass elif "R_PPC_ADDR16_HI" in row: # absolute hi of addr repl = f"{repl}@h" elif "R_PPC_ADDR16_HA" in row: # adjusted hi of addr repl = f"{repl}@ha" elif "R_PPC_ADDR16_LO" in row: # lo of addr repl = f"{repl}@l" elif "R_PPC_ADDR16" in row: # 16-bit absolute addr if "+0x7" in repl: # remove the very large addends as they are an artifact of (label-_SDA(2)_BASE_) # computations and are unimportant in a diff setting. if int(repl.split("+")[1],16) > 0x70000000: repl = repl.split("+")[0] elif "R_PPC_EMB_SDA21" in row: # small data area pass return before + repl + after def pad_mnemonic(line: str) -> str: if "\t" not in line: return line mn, args = line.split("\t", 1) return f"{mn:<7s} {args}" class Line(NamedTuple): mnemonic: str diff_row: str original: str normalized_original: str line_num: str branch_target: Optional[str] source_lines: List[str] comment: Optional[str] class DifferenceNormalizer: def normalize(self, mnemonic: str, row: str) -> str: """This should be called exactly once for each line.""" row = self._normalize_arch_specific(mnemonic, row) if args.ignore_large_imms: row = re.sub(re_large_imm, "", row) return row def _normalize_arch_specific(self, mnemonic: str, row: str) -> str: return row class DifferenceNormalizerAArch64(DifferenceNormalizer): def __init__(self) -> None: super().__init__() self._adrp_pair_registers: Set[str] = set() def _normalize_arch_specific(self, mnemonic: str, row: str) -> str: if args.ignore_addr_diffs: row = self._normalize_adrp_differences(mnemonic, row) row = self._normalize_bl(mnemonic, row) return row def _normalize_bl(self, mnemonic: str, row: str) -> str: if mnemonic != "bl": return row row, _ = split_off_branch(row) return row def _normalize_adrp_differences(self, mnemonic: str, row: str) -> str: """Identifies ADRP + LDR/ADD pairs that are used to access the GOT and suppresses any immediate differences. Whenever an ADRP is seen, the destination register is added to the set of registers that are part of an ADRP + LDR/ADD pair. Registers are removed from the set as soon as they are used for an LDR or ADD instruction which completes the pair. This method is somewhat crude but should manage to detect most such pairs. """ row_parts = row.split("\t", 1) if mnemonic == "adrp": self._adrp_pair_registers.add(row_parts[1].strip().split(",")[0]) row, _ = split_off_branch(row) elif mnemonic == "ldr": for reg in self._adrp_pair_registers: # ldr xxx, [reg] # ldr xxx, [reg, ] if f", [{reg}" in row_parts[1]: self._adrp_pair_registers.remove(reg) return normalize_imms(row) elif mnemonic == "add": for reg in self._adrp_pair_registers: # add reg, reg, if row_parts[1].startswith(f"{reg}, {reg}, "): self._adrp_pair_registers.remove(reg) return normalize_imms(row) return row def make_difference_normalizer() -> DifferenceNormalizer: if arch == "aarch64": return DifferenceNormalizerAArch64() return DifferenceNormalizer() def process(lines: List[str]) -> List[Line]: normalizer = make_difference_normalizer() skip_next = False source_lines = [] if not args.diff_obj: lines = lines[7:] if lines and not lines[-1]: lines.pop() output: List[Line] = [] stop_after_delay_slot = False for row in lines: if args.diff_obj and (">:" in row or not row): continue if args.source and (row and row[0] != " "): source_lines.append(row) continue if "R_AARCH64_" in row: # TODO: handle relocation continue if "R_MIPS_" in row: # N.B. Don't transform the diff rows, they already ignore immediates # if output[-1].diff_row != "": # output[-1] = output[-1].replace(diff_row=process_mips_reloc(row, output[-1].row_with_imm)) new_original = process_mips_reloc(row, output[-1].original) output[-1] = output[-1]._replace(original=new_original) continue if "R_PPC_" in row: new_original = process_ppc_reloc(row, output[-1].original) output[-1] = output[-1]._replace(original=new_original) continue m_comment = re.search(re_comment, row) comment = m_comment[0] if m_comment else None row = re.sub(re_comment, "", row) row = row.rstrip() tabs = row.split("\t") row = "\t".join(tabs[2:]) line_num = tabs[0].strip() if "\t" in row: row_parts = row.split("\t", 1) else: # powerpc-eabi-objdump doesn't use tabs row_parts = [part.lstrip() for part in row.split(" ", 1)] mnemonic = row_parts[0].strip() if mnemonic not in instructions_with_address_immediates: row = re.sub(re_int, lambda m: hexify_int(row, m), row) original = row normalized_original = normalizer.normalize(mnemonic, original) if skip_next: skip_next = False row = "" mnemonic = "" if mnemonic in branch_likely_instructions: skip_next = True row = re.sub(re_reg, "", row) row = re.sub(re_sprel, "addr(sp)", row) row_with_imm = row if mnemonic in instructions_with_address_immediates: row = row.strip() row, _ = split_off_branch(row) row += "" else: row = normalize_imms(row) branch_target = None if mnemonic in branch_instructions: target = row_parts[1].strip().split(",")[-1] if mnemonic in branch_likely_instructions: target = hex(int(target, 16) - 4)[2:] branch_target = target.strip() output.append( Line( mnemonic=mnemonic, diff_row=row, original=original, normalized_original=normalized_original, line_num=line_num, branch_target=branch_target, source_lines=source_lines, comment=comment, ) ) source_lines = [] if args.stop_jrra and mnemonic == "jr" and row_parts[1].strip() == "ra": stop_after_delay_slot = True elif stop_after_delay_slot: break return output def format_single_line_diff(line1: str, line2: str, column_width: int) -> str: return ansi_ljust(line1, column_width) + line2 class SymbolColorer: symbol_colors: Dict[str, str] def __init__(self, base_index: int) -> None: self.color_index = base_index self.symbol_colors = {} def color_symbol(self, s: str, t: Optional[str] = None) -> str: try: color = self.symbol_colors[s] except: color = COLOR_ROTATION[self.color_index % len(COLOR_ROTATION)] self.color_index += 1 self.symbol_colors[s] = color t = t or s return f"{color}{t}{Fore.RESET}" def normalize_imms(row: str) -> str: return re.sub(re_imm, "", row) def normalize_stack(row: str) -> str: return re.sub(re_sprel, "addr(sp)", row) def split_off_branch(line: str) -> Tuple[str, str]: parts = line.split(",") if len(parts) < 2: parts = line.split(None, 1) off = len(line) - len(parts[-1]) return line[:off], line[off:] ColorFunction = Callable[[str], str] def color_fields(pat: Pattern[str], out1: str, out2: str, color1: ColorFunction, color2: Optional[ColorFunction]=None) -> Tuple[str, str]: diffs = [of.group() != nf.group() for (of, nf) in zip(pat.finditer(out1), pat.finditer(out2))] it = iter(diffs) def maybe_color(color: ColorFunction, s: str) -> str: return color(s) if next(it, False) else f"{Style.RESET_ALL}{s}" out1 = pat.sub(lambda m: maybe_color(color1, m.group()), out1) it = iter(diffs) out2 = pat.sub(lambda m: maybe_color(color2 or color1, m.group()), out2) return out1, out2 def color_branch_imms(br1: str, br2: str) -> Tuple[str, str]: if br1 != br2: br1 = f"{Fore.LIGHTBLUE_EX}{br1}{Style.RESET_ALL}" br2 = f"{Fore.LIGHTBLUE_EX}{br2}{Style.RESET_ALL}" return br1, br2 def diff_sequences_difflib( seq1: List[str], seq2: List[str] ) -> List[Tuple[str, int, int, int, int]]: differ = difflib.SequenceMatcher(a=seq1, b=seq2, autojunk=False) return differ.get_opcodes() def diff_sequences( seq1: List[str], seq2: List[str] ) -> List[Tuple[str, int, int, int, int]]: if ( args.algorithm != "levenshtein" or len(seq1) * len(seq2) > 4 * 10 ** 8 or len(seq1) + len(seq2) >= 0x110000 ): return diff_sequences_difflib(seq1, seq2) # The Levenshtein library assumes that we compare strings, not lists. Convert. # (Per the check above we know we have fewer than 0x110000 unique elements, so chr() works.) remapping: Dict[str, str] = {} def remap(seq: List[str]) -> str: seq = seq[:] for i in range(len(seq)): val = remapping.get(seq[i]) if val is None: val = chr(len(remapping)) remapping[seq[i]] = val seq[i] = val return "".join(seq) rem1 = remap(seq1) rem2 = remap(seq2) return Levenshtein.opcodes(rem1, rem2) # type: ignore def diff_lines( lines1: List[Line], lines2: List[Line], ) -> List[Tuple[Optional[Line], Optional[Line]]]: ret = [] for (tag, i1, i2, j1, j2) in diff_sequences( [line.mnemonic for line in lines1], [line.mnemonic for line in lines2], ): for line1, line2 in itertools.zip_longest(lines1[i1:i2], lines2[j1:j2]): if tag == "replace": if line1 is None: tag = "insert" elif line2 is None: tag = "delete" elif tag == "insert": assert line1 is None elif tag == "delete": assert line2 is None ret.append((line1, line2)) return ret class OutputLine: base: Optional[str] fmt2: str key2: Optional[str] def __init__(self, base: Optional[str], fmt2: str, key2: Optional[str]) -> None: self.base = base self.fmt2 = fmt2 self.key2 = key2 def __eq__(self, other: object) -> bool: if not isinstance(other, OutputLine): return NotImplemented return self.key2 == other.key2 def __hash__(self) -> int: return hash(self.key2) def do_diff(basedump: str, mydump: str) -> List[OutputLine]: output: List[OutputLine] = [] lines1 = process(basedump.split("\n")) lines2 = process(mydump.split("\n")) sc1 = SymbolColorer(0) sc2 = SymbolColorer(0) sc3 = SymbolColorer(4) sc4 = SymbolColorer(4) sc5 = SymbolColorer(0) sc6 = SymbolColorer(0) bts1: Set[str] = set() bts2: Set[str] = set() if args.show_branches: for (lines, btset, sc) in [ (lines1, bts1, sc5), (lines2, bts2, sc6), ]: for line in lines: bt = line.branch_target if bt is not None: btset.add(bt + ":") sc.color_symbol(bt + ":") for (line1, line2) in diff_lines(lines1, lines2): line_color1 = line_color2 = sym_color = Fore.RESET line_prefix = " " if line1 and line2 and line1.diff_row == line2.diff_row: if line1.normalized_original == line2.normalized_original: out1 = line1.original out2 = line2.original elif line1.diff_row == "": out1 = f"{Style.BRIGHT}{Fore.LIGHTBLACK_EX}{line1.original}" out2 = f"{Style.BRIGHT}{Fore.LIGHTBLACK_EX}{line2.original}" else: mnemonic = line1.original.split()[0] out1, out2 = line1.original, line2.original branch1 = branch2 = "" if mnemonic in instructions_with_address_immediates: out1, branch1 = split_off_branch(line1.original) out2, branch2 = split_off_branch(line2.original) branchless1 = out1 branchless2 = out2 out1, out2 = color_fields(re_imm, out1, out2, lambda s: f"{Fore.LIGHTBLUE_EX}{s}{Style.RESET_ALL}") same_relative_target = False if line1.branch_target is not None and line2.branch_target is not None: relative_target1 = eval_line_num(line1.branch_target) - eval_line_num(line1.line_num) relative_target2 = eval_line_num(line2.branch_target) - eval_line_num(line2.line_num) same_relative_target = relative_target1 == relative_target2 if not same_relative_target: branch1, branch2 = color_branch_imms(branch1, branch2) out1 += branch1 out2 += branch2 if normalize_imms(branchless1) == normalize_imms(branchless2): if not same_relative_target: # only imms differences sym_color = Fore.LIGHTBLUE_EX line_prefix = "i" else: out1, out2 = color_fields(re_sprel, out1, out2, sc3.color_symbol, sc4.color_symbol) if normalize_stack(branchless1) == normalize_stack(branchless2): # only stack differences (luckily stack and imm # differences can't be combined in MIPS, so we # don't have to think about that case) sym_color = Fore.YELLOW line_prefix = "s" else: # regs differences and maybe imms as well out1, out2 = color_fields(re_reg, out1, out2, sc1.color_symbol, sc2.color_symbol) line_color1 = line_color2 = sym_color = Fore.YELLOW line_prefix = "r" elif line1 and line2: line_prefix = "|" line_color1 = Fore.LIGHTBLUE_EX line_color2 = Fore.LIGHTBLUE_EX sym_color = Fore.LIGHTBLUE_EX out1 = line1.original out2 = line2.original elif line1: line_prefix = "<" line_color1 = sym_color = Fore.RED out1 = line1.original out2 = "" elif line2: line_prefix = ">" line_color2 = sym_color = Fore.GREEN out1 = "" out2 = line2.original if args.source and line2 and line2.comment: out2 += f" {line2.comment}" def format_part( out: str, line: Optional[Line], line_color: str, btset: Set[str], sc: SymbolColorer, ) -> Optional[str]: if line is None: return None in_arrow = " " out_arrow = "" if args.show_branches: if line.line_num in btset: in_arrow = sc.color_symbol(line.line_num, "~>") + line_color if line.branch_target is not None: out_arrow = " " + sc.color_symbol(line.branch_target + ":", "~>") out = pad_mnemonic(out) return f"{line_color}{line.line_num} {in_arrow} {out}{Style.RESET_ALL}{out_arrow}" part1 = format_part(out1, line1, line_color1, bts1, sc5) part2 = format_part(out2, line2, line_color2, bts2, sc6) key2 = line2.original if line2 else None mid = f"{sym_color}{line_prefix}" if line2: for source_line in line2.source_lines: color = Style.DIM # File names and function names if source_line and source_line[0] != "│": color += Style.BRIGHT # Function names if source_line.endswith("():"): # Underline. Colorama does not provide this feature, unfortunately. color += "\u001b[4m" try: source_line = cxxfilt.demangle( source_line[:-3], external_only=False ) except: pass output.append( OutputLine( None, f" {color}{source_line}{Style.RESET_ALL}", source_line, ) ) fmt2 = mid + " " + (part2 or "") output.append(OutputLine(part1, fmt2, key2)) return output def chunk_diff(diff: List[OutputLine]) -> List[Union[List[OutputLine], OutputLine]]: cur_right: List[OutputLine] = [] chunks: List[Union[List[OutputLine], OutputLine]] = [] for output_line in diff: if output_line.base is not None: chunks.append(cur_right) chunks.append(output_line) cur_right = [] else: cur_right.append(output_line) chunks.append(cur_right) return chunks def format_diff( old_diff: List[OutputLine], new_diff: List[OutputLine] ) -> Tuple[str, List[str]]: old_chunks = chunk_diff(old_diff) new_chunks = chunk_diff(new_diff) output: List[Tuple[str, OutputLine, OutputLine]] = [] assert len(old_chunks) == len(new_chunks), "same target" empty = OutputLine("", "", None) for old_chunk, new_chunk in zip(old_chunks, new_chunks): if isinstance(old_chunk, list): assert isinstance(new_chunk, list) if not old_chunk and not new_chunk: # Most of the time lines sync up without insertions/deletions, # and there's no interdiffing to be done. continue differ = difflib.SequenceMatcher(a=old_chunk, b=new_chunk, autojunk=False) for (tag, i1, i2, j1, j2) in differ.get_opcodes(): if tag in ["equal", "replace"]: for i, j in zip(range(i1, i2), range(j1, j2)): output.append(("", old_chunk[i], new_chunk[j])) if tag in ["insert", "replace"]: for j in range(j1 + i2 - i1, j2): output.append(("", empty, new_chunk[j])) if tag in ["delete", "replace"]: for i in range(i1 + j2 - j1, i2): output.append(("", old_chunk[i], empty)) else: assert isinstance(new_chunk, OutputLine) assert new_chunk.base # old_chunk.base and new_chunk.base have the same text since # both diffs are based on the same target, but they might # differ in color. Use the new version. output.append((new_chunk.base, old_chunk, new_chunk)) # TODO: status line, with e.g. approximate permuter score? width = args.column_width if args.threeway: header_line = "TARGET".ljust(width) + " CURRENT".ljust(width) + " PREVIOUS" diff_lines = [ ansi_ljust(base, width) + ansi_ljust(new.fmt2, width) + (old.fmt2 or "-" if old != new else "") for (base, old, new) in output ] else: header_line = "" diff_lines = [ ansi_ljust(base, width) + new.fmt2 for (base, old, new) in output if base or new.key2 is not None ] return header_line, diff_lines def debounced_fs_watch( targets: List[str], outq: "queue.Queue[Optional[float]]", debounce_delay: float, ) -> None: import watchdog.events # type: ignore import watchdog.observers # type: ignore class WatchEventHandler(watchdog.events.FileSystemEventHandler): # type: ignore def __init__( self, queue: "queue.Queue[float]", file_targets: List[str] ) -> None: self.queue = queue self.file_targets = file_targets def on_modified(self, ev: object) -> None: if isinstance(ev, watchdog.events.FileModifiedEvent): self.changed(ev.src_path) def on_moved(self, ev: object) -> None: if isinstance(ev, watchdog.events.FileMovedEvent): self.changed(ev.dest_path) def should_notify(self, path: str) -> bool: for target in self.file_targets: if path == target: return True if args.make and any( path.endswith(suffix) for suffix in FS_WATCH_EXTENSIONS ): return True return False def changed(self, path: str) -> None: if self.should_notify(path): self.queue.put(time.time()) def debounce_thread() -> NoReturn: listenq: "queue.Queue[float]" = queue.Queue() file_targets: List[str] = [] event_handler = WatchEventHandler(listenq, file_targets) observer = watchdog.observers.Observer() observed = set() for target in targets: if os.path.isdir(target): observer.schedule(event_handler, target, recursive=True) else: file_targets.append(target) target = os.path.dirname(target) or "." if target not in observed: observed.add(target) observer.schedule(event_handler, target) observer.start() while True: t = listenq.get() more = True while more: delay = t + debounce_delay - time.time() if delay > 0: time.sleep(delay) # consume entire queue more = False try: while True: t = listenq.get(block=False) more = True except queue.Empty: pass outq.put(t) th = threading.Thread(target=debounce_thread, daemon=True) th.start() class Display: basedump: str mydump: str emsg: Optional[str] last_diff_output: Optional[List[OutputLine]] pending_update: Optional[Tuple[str, bool]] ready_queue: "queue.Queue[None]" watch_queue: "queue.Queue[Optional[float]]" less_proc: "Optional[subprocess.Popen[bytes]]" def __init__(self, basedump: str, mydump: str) -> None: self.basedump = basedump self.mydump = mydump self.emsg = None self.last_diff_output = None def run_less(self) -> "Tuple[subprocess.Popen[bytes], subprocess.Popen[bytes]]": if self.emsg is not None: output = self.emsg else: diff_output = do_diff(self.basedump, self.mydump) last_diff_output = self.last_diff_output or diff_output if args.threeway != "base" or not self.last_diff_output: self.last_diff_output = diff_output header, diff_lines = format_diff(last_diff_output, diff_output) header_lines = [header] if header else [] output = "\n".join(header_lines + diff_lines[args.skip_lines :]) # Pipe the output through 'tail' and only then to less, to ensure the # write call doesn't block. ('tail' has to buffer all its input before # it starts writing.) This also means we don't have to deal with pipe # closure errors. buffer_proc = subprocess.Popen( BUFFER_CMD, stdin=subprocess.PIPE, stdout=subprocess.PIPE ) less_proc = subprocess.Popen(LESS_CMD, stdin=buffer_proc.stdout) assert buffer_proc.stdin assert buffer_proc.stdout buffer_proc.stdin.write(output.encode()) buffer_proc.stdin.close() buffer_proc.stdout.close() return (buffer_proc, less_proc) def run_sync(self) -> None: proca, procb = self.run_less() procb.wait() proca.wait() def run_async(self, watch_queue: "queue.Queue[Optional[float]]") -> None: self.watch_queue = watch_queue self.ready_queue = queue.Queue() self.pending_update = None dthread = threading.Thread(target=self.display_thread) dthread.start() self.ready_queue.get() def display_thread(self) -> None: proca, procb = self.run_less() self.less_proc = procb self.ready_queue.put(None) while True: ret = procb.wait() proca.wait() self.less_proc = None if ret != 0: # fix the terminal os.system("tput reset") if ret != 0 and self.pending_update is not None: # killed by program with the intent to refresh msg, error = self.pending_update self.pending_update = None if not error: self.mydump = msg self.emsg = None else: self.emsg = msg proca, procb = self.run_less() self.less_proc = procb self.ready_queue.put(None) else: # terminated by user, or killed self.watch_queue.put(None) self.ready_queue.put(None) break def progress(self, msg: str) -> None: # Write message to top-left corner sys.stdout.write("\x1b7\x1b[1;1f{}\x1b8".format(msg + " ")) sys.stdout.flush() def update(self, text: str, error: bool) -> None: if not error and not self.emsg and text == self.mydump: self.progress("Unchanged. ") return self.pending_update = (text, error) if not self.less_proc: return self.less_proc.kill() self.ready_queue.get() def terminate(self) -> None: if not self.less_proc: return self.less_proc.kill() self.ready_queue.get() def main() -> None: if args.diff_elf_symbol: make_target, basecmd, mycmd = dump_elf() elif args.diff_obj: make_target, basecmd, mycmd = dump_objfile() else: make_target, basecmd, mycmd = dump_binary() if args.write_asm is not None: mydump = run_objdump(mycmd) with open(args.write_asm, "w") as f: f.write(mydump) print(f"Wrote assembly to {args.write_asm}.") sys.exit(0) if args.base_asm is not None: with open(args.base_asm) as f: basedump = f.read() else: basedump = run_objdump(basecmd) mydump = run_objdump(mycmd) display = Display(basedump, mydump) if not args.watch: display.run_sync() else: if not args.make: yn = input( "Warning: watch-mode (-w) enabled without auto-make (-m). " "You will have to run make manually. Ok? (Y/n) " ) if yn.lower() == "n": return if args.make: watch_sources = None watch_sources_for_target_fn = getattr( diff_settings, "watch_sources_for_target", None ) if watch_sources_for_target_fn: watch_sources = watch_sources_for_target_fn(make_target) watch_sources = watch_sources or source_directories if not watch_sources: fail("Missing source_directories config, don't know what to watch.") else: watch_sources = [make_target] q: "queue.Queue[Optional[float]]" = queue.Queue() debounced_fs_watch(watch_sources, q, DEBOUNCE_DELAY) display.run_async(q) last_build = 0.0 try: while True: t = q.get() if t is None: break if t < last_build: continue last_build = time.time() if args.make: display.progress("Building...") ret = run_make_capture_output(make_target) if ret.returncode != 0: display.update( ret.stderr.decode("utf-8-sig", "replace") or ret.stdout.decode("utf-8-sig", "replace"), error=True, ) continue mydump = run_objdump(mycmd) display.update(mydump, error=False) except KeyboardInterrupt: display.terminate() main()