oot/diff.py
2021-01-03 15:29:01 -05:00

1603 lines
52 KiB
Python
Executable File

#!/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")
makeflags: List[str] = 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(["make"] + makeflags + [target])
def run_make_capture_output(target: str) -> "subprocess.CompletedProcess[bytes]":
return subprocess.run(
["make"] + makeflags + [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"(<.*?>|//.*$)")
# GPRs and FP registers: X0-X30, W0-W30, [DSHQ]0..31
# The zero registers and SP should not be in this list.
re_reg = re.compile(r"\$?\b([dshq][12]?[0-9]|[dshq]3[01]|[xw][12]?[0-9]|[xw]30)\b")
re_sprel = re.compile(r"sp, #-?(0x[0-9a-fA-F]+|[0-9]+)\b")
re_large_imm = re.compile(r"-?[1-9][0-9]{2,}|-?0x[0-9a-f]{3,}")
re_imm = re.compile(r"(?<!sp, )#-?(0x[0-9a-fA-F]+|[0-9]+)\b")
arch_flags = []
forbidden = set(string.ascii_letters + "_")
branch_likely_instructions = set()
branch_instructions = {
"bl",
"b",
"b.eq",
"b.ne",
"b.cs",
"b.hs",
"b.cc",
"b.lo",
"b.mi",
"b.pl",
"b.vs",
"b.vc",
"b.hi",
"b.ls",
"b.ge",
"b.lt",
"b.gt",
"b.le",
"cbz",
"cbnz",
"tbz",
"tbnz",
}
instructions_with_address_immediates = branch_instructions.union({"adrp"})
elif arch == "ppc":
re_int = re.compile(r"[0-9]+")
re_comment = re.compile(r"(<.*?>|//.*$)")
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, "<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, <imm>]
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, <imm>
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 != "<delay-slot>":
# 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 = "<delay-slot>"
mnemonic = "<delay-slot>"
if mnemonic in branch_likely_instructions:
skip_next = True
row = re.sub(re_reg, "<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 += "<imm>"
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, "<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 == "<delay-slot>":
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()