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oot/tools/fix_bss.py
cadmic aed15faaf4
Use BSS section start from map file in fix_bss.py instead of guessing (#2045)
* Use BSS section start from map file

* Expand comment about section start heuristic

* Reword
2024-08-18 22:12:02 +02:00

784 lines
27 KiB
Python
Executable file

#!/usr/bin/env python3
# SPDX-FileCopyrightText: 2024 zeldaret
# SPDX-License-Identifier: CC0-1.0
from __future__ import annotations
import argparse
from collections import Counter
import colorama
from dataclasses import dataclass
import io
import multiprocessing
import multiprocessing.pool
from pathlib import Path
import re
import shlex
import sys
import time
import traceback
from typing import BinaryIO, Iterator
from ido_block_numbers import (
generate_make_log,
find_compiler_command_line,
run_cfe,
SymbolTableEntry,
UcodeOp,
)
import elftools.elf.elffile
import mapfile_parser.mapfile
def read_u32(f: BinaryIO, offset: int) -> int:
f.seek(offset)
return int.from_bytes(f.read(4), "big")
def read_u16(f: BinaryIO, offset: int) -> int:
f.seek(offset)
return int.from_bytes(f.read(2), "big")
def read_s16(f: BinaryIO, offset: int) -> int:
f.seek(offset)
return int.from_bytes(f.read(2), "big", signed=True)
class FixBssException(Exception):
pass
@dataclass
class Reloc:
name: str
offset_32: int | None
offset_hi16: int | None
offset_lo16: int | None
addend: int
@dataclass
class Pointer:
name: str
addend: int
base_value: int
build_value: int
@dataclass
class BssSection:
start_address: int
pointers: list[Pointer]
# Read relocations from an ELF file section
def read_relocs(object_path: Path, section_name: str) -> list[Reloc]:
with open(object_path, "rb") as f:
elffile = elftools.elf.elffile.ELFFile(f)
symtab = elffile.get_section_by_name(".symtab")
data = elffile.get_section_by_name(section_name).data()
reloc_section = elffile.get_section_by_name(f".rel{section_name}")
if reloc_section is None:
return []
relocs = []
offset_hi16 = 0
for reloc in reloc_section.iter_relocations():
reloc_offset = reloc.entry["r_offset"]
reloc_type = reloc.entry["r_info_type"]
reloc_name = symtab.get_symbol(reloc.entry["r_info_sym"]).name
if reloc_type == 2: # R_MIPS_32
offset_32 = reloc_offset
addend = int.from_bytes(
data[reloc_offset : reloc_offset + 4], "big", signed=True
)
relocs.append(Reloc(reloc_name, offset_32, None, None, addend))
elif reloc_type == 4: # R_MIPS_26
pass
elif reloc_type == 5: # R_MIPS_HI16
offset_hi16 = reloc_offset
elif reloc_type == 6: # R_MIPS_LO16
offset_lo16 = reloc_offset
addend_hi16 = int.from_bytes(
data[offset_hi16 + 2 : offset_hi16 + 4], "big", signed=False
)
addend_lo16 = int.from_bytes(
data[offset_lo16 + 2 : offset_lo16 + 4], "big", signed=True
)
addend = (addend_hi16 << 16) + addend_lo16
relocs.append(Reloc(reloc_name, None, offset_hi16, offset_lo16, addend))
else:
raise NotImplementedError(f"Unsupported relocation type: {reloc_type}")
return relocs
def get_file_pointers(
file: mapfile_parser.mapfile.File,
base: BinaryIO,
build: BinaryIO,
) -> list[Pointer]:
pointers = []
# TODO: open each ELF file only once instead of once per section?
for reloc in read_relocs(file.filepath, file.sectionType):
if reloc.offset_32 is not None:
base_value = read_u32(base, file.vrom + reloc.offset_32)
build_value = read_u32(build, file.vrom + reloc.offset_32)
elif reloc.offset_hi16 is not None and reloc.offset_lo16 is not None:
if (
read_u16(base, file.vrom + reloc.offset_hi16)
!= read_u16(build, file.vrom + reloc.offset_hi16)
) or (
read_u16(base, file.vrom + reloc.offset_lo16)
!= read_u16(build, file.vrom + reloc.offset_lo16)
):
raise FixBssException(
f"Reference to {reloc.name} in {file.filepath} is in a shifted or non-matching portion of the ROM.\n"
"Please ensure that the only differences between the baserom and the current build are due to BSS ordering."
)
base_value = (
read_u16(base, file.vrom + reloc.offset_hi16 + 2) << 16
) + read_s16(base, file.vrom + reloc.offset_lo16 + 2)
build_value = (
read_u16(build, file.vrom + reloc.offset_hi16 + 2) << 16
) + read_s16(build, file.vrom + reloc.offset_lo16 + 2)
else:
assert False, "Invalid relocation"
pointers.append(Pointer(reloc.name, reloc.addend, base_value, build_value))
return pointers
base = None
build = None
def get_file_pointers_worker_init(version: str):
global base
global build
base = open(f"baseroms/{version}/baserom-decompressed.z64", "rb")
build = open(f"build/{version}/oot-{version}.z64", "rb")
def get_file_pointers_worker(file: mapfile_parser.mapfile.File) -> list[Pointer]:
assert base is not None
assert build is not None
return get_file_pointers(file, base, build)
# Compare pointers between the baserom and the current build, returning a dictionary from
# C files to a list of pointers into their BSS sections
def compare_pointers(version: str) -> dict[Path, BssSection]:
mapfile_path = Path(f"build/{version}/oot-{version}.map")
if not mapfile_path.exists():
raise FixBssException(f"Could not open {mapfile_path}")
mapfile = mapfile_parser.mapfile.MapFile()
mapfile.readMapFile(mapfile_path)
# Segments built from source code (filtering out assets)
source_code_segments = []
for mapfile_segment in mapfile:
if not (
mapfile_segment.name.startswith("..boot")
or mapfile_segment.name.startswith("..code")
or mapfile_segment.name.startswith("..buffers")
or mapfile_segment.name.startswith("..ovl_")
):
continue
source_code_segments.append(mapfile_segment)
# Find all pointers with different values
if not sys.stdout.isatty():
print(f"Comparing pointers between baserom and build ...")
pointers = []
file_results = []
with multiprocessing.Pool(
initializer=get_file_pointers_worker_init,
initargs=(version,),
) as p:
for mapfile_segment in source_code_segments:
for file in mapfile_segment:
if not str(file.filepath).endswith(".o"):
continue
if file.sectionType == ".bss":
continue
file_result = p.apply_async(get_file_pointers_worker, (file,))
file_results.append(file_result)
# Report progress and wait until all files are done
num_files = len(file_results)
while True:
time.sleep(0.010)
num_files_done = sum(file_result.ready() for file_result in file_results)
if sys.stdout.isatty():
print(
f"Comparing pointers between baserom and build ... {num_files_done:>{len(f'{num_files}')}}/{num_files}",
end="\r",
)
if num_files_done == num_files:
break
if sys.stdout.isatty():
print("")
# Collect results and check for errors
for file_result in file_results:
try:
pointers.extend(file_result.get())
except FixBssException as e:
print(f"{colorama.Fore.RED}Error: {str(e)}{colorama.Fore.RESET}")
sys.exit(1)
# Remove duplicates and sort by baserom address
pointers = list({p.base_value: p for p in pointers}.values())
pointers.sort(key=lambda p: p.base_value)
# Go through sections and collect differences
bss_sections = {}
for mapfile_segment in source_code_segments:
for file in mapfile_segment:
if not file.sectionType == ".bss":
continue
pointers_in_section = [
p
for p in pointers
if file.vram <= p.build_value < file.vram + file.size
]
c_file = file.filepath.relative_to(f"build/{version}").with_suffix(".c")
bss_sections[c_file] = BssSection(file.vram, pointers_in_section)
return bss_sections
@dataclass
class Pragma:
line_number: int
block_number: int
amount: int
# A BSS variable in the source code
@dataclass
class BssVariable:
block_number: int
name: str
size: int
align: int
# A BSS variable with its offset in the compiled .bss section
@dataclass
class BssSymbol:
name: str
offset: int
size: int
align: int
INCREMENT_BLOCK_NUMBER_RE = re.compile(r"increment_block_number_(\d+)_(\d+)")
# Find increment_block_number pragmas by parsing the symbol names generated by preprocess.py.
# This is pretty ugly but it seems more reliable than trying to determine the line numbers of
# BSS variables in the C file.
def find_pragmas(symbol_table: list[SymbolTableEntry]) -> list[Pragma]:
# Keep track of first block number and count for each line number
first_block_number = {}
amounts: Counter[int] = Counter()
for block_number, entry in enumerate(symbol_table):
if match := INCREMENT_BLOCK_NUMBER_RE.match(entry.name):
line_number = int(match.group(1))
if line_number not in first_block_number:
first_block_number[line_number] = block_number
amounts[line_number] += 1
pragmas = []
for line_number, block_number in sorted(first_block_number.items()):
pragmas.append(Pragma(line_number, block_number, amounts[line_number]))
return pragmas
# Find all BSS variables from IDO's symbol table and U-Code output.
def find_bss_variables(
symbol_table: list[SymbolTableEntry], ucode: list[UcodeOp]
) -> list[BssVariable]:
bss_variables = []
init_block_numbers = set(op.i1 for op in ucode if op.opcode_name == "init")
last_function_name = None
for op in ucode:
# gsym: file-level global symbol
# lsym: file-level static symbol
# fsym: function-level static symbol
if op.opcode_name in ("gsym", "lsym", "fsym"):
block_number = op.i1
if block_number in init_block_numbers:
continue # not BSS
name = symbol_table[block_number].name
if op.opcode_name == "fsym":
name = f"{last_function_name}::{name}"
size = op.args[0]
align = 1 << op.lexlev
# TODO: IDO seems to automatically align anything with size 8 or more to
# an 8-byte boundary in BSS. Is this correct?
if size >= 8:
align = 8
bss_variables.append(BssVariable(block_number, name, size, align))
elif op.opcode_name == "ent":
last_function_name = symbol_table[op.i1].name
bss_variables.sort(key=lambda var: var.block_number)
return bss_variables
# Predict offsets of BSS variables in the build.
def predict_bss_ordering(variables: list[BssVariable]) -> list[BssSymbol]:
bss_symbols = []
offset = 0
# Sort by block number mod 256 (for ties, the original order is preserved)
for var in sorted(variables, key=lambda var: var.block_number % 256):
size = var.size
align = var.align
offset = (offset + align - 1) & ~(align - 1)
bss_symbols.append(BssSymbol(var.name, offset, size, align))
offset += size
return bss_symbols
# Match up BSS variables between the baserom and the build using the pointers from relocations.
# Note that we may not be able to match all variables if a variable is not referenced by any pointer.
def determine_base_bss_ordering(
build_bss_symbols: list[BssSymbol],
bss_section: BssSection,
) -> list[BssSymbol]:
# For the baserom, assume that the lowest address is the start of the BSS section. This might
# not be true if the first BSS variable is not referenced, but in practice this doesn't seem
# to happen for the files which typically have BSS ordering issues.
base_start_address = min(p.base_value for p in bss_section.pointers)
found_symbols: dict[str, BssSymbol] = {}
for p in bss_section.pointers:
base_offset = p.base_value - base_start_address
build_offset = p.build_value - bss_section.start_address
new_symbol = None
new_offset = 0
for symbol in build_bss_symbols:
if (
symbol.offset <= build_offset
and build_offset < symbol.offset + symbol.size
):
new_symbol = symbol
new_offset = base_offset - (build_offset - symbol.offset)
break
if new_symbol is None:
if p.addend > 0:
addend_str = f"+0x{p.addend:X}"
elif p.addend < 0:
addend_str = f"-0x{-p.addend:X}"
else:
addend_str = ""
raise FixBssException(
f"Could not find BSS symbol for pointer {p.name}{addend_str} "
f"(base address 0x{p.base_value:08X}, build address 0x{p.build_value:08X})"
)
if new_symbol.name in found_symbols:
# Sanity check that offsets agree
existing_offset = found_symbols[new_symbol.name].offset
if new_offset != existing_offset:
raise FixBssException(
f"BSS symbol {new_symbol.name} found at conflicting offsets in this baserom "
f"(0x{existing_offset:04X} and 0x{new_offset:04X}). Is the build up-to-date?"
)
else:
found_symbols[new_symbol.name] = BssSymbol(
new_symbol.name, new_offset, new_symbol.size, new_symbol.align
)
return list(sorted(found_symbols.values(), key=lambda symbol: symbol.offset))
# Generate a sequence of integers in the range [0, 256) with a 2-adic valuation of exactly `nu`.
# The 2-adic valuation of an integer n is the largest k such that 2^k divides n
# (see https://en.wikipedia.org/wiki/P-adic_valuation), and for convenience we define
# the 2-adic valuation of 0 to be 8. Here's what the sequences look like for nu = 0..8:
# 8: 0
# 7: 128
# 6: 64, 192
# 5: 32, 96, 160, 224
# 4: 16, 48, 80, 112, ...
# 3: 8, 24, 40, 56, ...
# 2: 4, 12, 20, 28, ...
# 1: 2, 6, 10, 14, ...
# 0: 1, 3, 5, 7, ...
def gen_seq(nu: int) -> Iterator[int]:
if nu == 8:
yield 0
else:
for i in range(1 << (7 - nu)):
yield (2 * i + 1) * (1 << nu)
# Yields all n-tuples of integers in the range [0, 256) with minimum 2-adic valuation
# of exactly `min_nu`.
def gen_candidates_impl(n: int, min_nu: int) -> Iterator[tuple[int, ...]]:
if n == 1:
for n in gen_seq(min_nu):
yield (n,)
else:
# (a, *b) has min 2-adic valuation = min_nu if and only if either:
# a has 2-adic valuation > min_nu and b has min 2-adic valuation == min_nu
# a has 2-adic valuation == min_nu and b has min 2-adic valuation >= min_nu
for min_nu_a in reversed(range(min_nu + 1, 9)):
for a in gen_seq(min_nu_a):
for b in gen_candidates_impl(n - 1, min_nu):
yield (a, *b)
for a in gen_seq(min_nu):
for min_nu_b in reversed(range(min_nu, 9)):
for b in gen_candidates_impl(n - 1, min_nu_b):
yield (a, *b)
# Yields all n-tuples of integers in the range [0, 256), ordered by descending minimum
# 2-adic valuation of the elements in the tuple. For example, for n = 2 the sequence is:
# (0, 0), (0, 128), (128, 0), (128, 128), (0, 64), (0, 192), (128, 64), (128, 192), ...
def gen_candidates(n: int) -> Iterator[tuple[int, ...]]:
for nu in reversed(range(9)):
yield from gen_candidates_impl(n, nu)
# Determine a new set of increment_block_number pragmas that will fix the BSS ordering.
def solve_bss_ordering(
pragmas: list[Pragma],
bss_variables: list[BssVariable],
base_bss_symbols: list[BssSymbol],
) -> list[Pragma]:
base_symbols_by_name = {symbol.name: symbol for symbol in base_bss_symbols}
# Our "algorithm" just tries all possible combinations of increment_block_number amounts,
# which can get very slow with more than a few pragmas. But, we order the candidates in a
# binary-search-esque way to try to find a solution faster.
for new_amounts in gen_candidates(len(pragmas)):
# Generate new block numbers
new_bss_variables = []
for var in bss_variables:
new_block_number = var.block_number
for pragma, new_amount in zip(pragmas, new_amounts):
if var.block_number >= pragma.block_number:
new_block_number += new_amount - pragma.amount
new_bss_variables.append(
BssVariable(new_block_number, var.name, var.size, var.align)
)
# Predict new BSS and check if new ordering matches
new_bss_symbols = predict_bss_ordering(new_bss_variables)
bss_ordering_matches = True
for symbol in new_bss_symbols:
base_symbol = base_symbols_by_name.get(symbol.name)
if base_symbol is None:
continue
if symbol.offset != base_symbol.offset:
bss_ordering_matches = False
break
if bss_ordering_matches:
new_pragmas = []
for pragma, new_amount in zip(pragmas, new_amounts):
new_pragmas.append(
Pragma(pragma.line_number, pragma.block_number, new_amount)
)
return new_pragmas
raise FixBssException("Could not find any solutions")
# Parses #pragma increment_block_number (with line continuations already removed)
def parse_pragma(pragma_string: str) -> dict[str, int]:
amounts = {}
for part in pragma_string.replace('"', "").split()[2:]:
kv = part.split(":")
if len(kv) != 2:
raise FixBssException(
"#pragma increment_block_number"
f' arguments must be version:amount pairs, not "{part}"'
)
try:
amount = int(kv[1])
except ValueError:
raise FixBssException(
"#pragma increment_block_number"
f' amount must be an integer, not "{kv[1]}" (in "{part}")'
)
amounts[kv[0]] = amount
return amounts
# Formats #pragma increment_block_number as a list of lines
def format_pragma(amounts: dict[str, int], max_line_length: int) -> list[str]:
lines = []
pragma_start = "#pragma increment_block_number "
current_line = pragma_start + '"'
first = True
for version, amount in sorted(amounts.items()):
part = f"{version}:{amount}"
if len(current_line) + len(part) + len('" \\') > max_line_length:
lines.append(current_line + '" ')
current_line = " " * len(pragma_start) + '"'
first = True
if not first:
current_line += " "
current_line += part
first = False
lines.append(current_line + '"\n')
if len(lines) >= 2:
# add and align vertically all continuation \ characters
n_align = max(map(len, lines[:-1]))
for i in range(len(lines) - 1):
lines[i] = f"{lines[i]:{n_align}}\\\n"
return lines
def update_source_file(version_to_update: str, file: Path, new_pragmas: list[Pragma]):
with open(file, "r", encoding="utf-8") as f:
lines = f.readlines()
replace_lines: list[tuple[int, int, list[str]]] = []
for pragma in new_pragmas:
i = pragma.line_number - 1
if not lines[i].startswith("#pragma increment_block_number"):
raise FixBssException(
f"Expected #pragma increment_block_number on line {pragma.line_number}"
)
# list the pragma line and any continuation line
pragma_lines = [lines[i]]
while pragma_lines[-1].endswith("\\\n"):
i += 1
pragma_lines.append(lines[i])
# concatenate all lines into one
pragma_string = "".join(s.replace("\\\n", "") for s in pragma_lines)
amounts = parse_pragma(pragma_string)
amounts[version_to_update] = pragma.amount
column_limit = 120 # matches .clang-format's ColumnLimit
new_pragma_lines = format_pragma(amounts, column_limit)
replace_lines.append(
(
pragma.line_number - 1,
pragma.line_number - 1 + len(pragma_lines),
new_pragma_lines,
)
)
# Replace the pragma lines starting from the end of the file, so the line numbers
# for pragmas earlier in the file stay accurate.
replace_lines.sort(key=lambda it: it[0], reverse=True)
for start, end, new_pragma_lines in replace_lines:
del lines[start:end]
lines[start:start] = new_pragma_lines
with open(file, "w", encoding="utf-8") as f:
f.writelines(lines)
def process_file(
file: Path,
bss_section: BssSection,
make_log: list[str],
dry_run: bool,
version: str,
):
print(f"{colorama.Fore.CYAN}Processing {file} ...{colorama.Fore.RESET}")
command_line = find_compiler_command_line(make_log, file)
if command_line is None:
raise FixBssException(f"Could not determine compiler command line for {file}")
print(f"Compiler command: {shlex.join(command_line)}")
symbol_table, ucode = run_cfe(command_line, keep_files=False)
bss_variables = find_bss_variables(symbol_table, ucode)
print("BSS variables:")
for var in bss_variables:
i = var.block_number
print(
f" {i:>6} [{i%256:>3}]: size=0x{var.size:04X} align=0x{var.align:X} {var.name}"
)
build_bss_symbols = predict_bss_ordering(bss_variables)
print("Current build BSS ordering:")
for symbol in build_bss_symbols:
print(
f" offset=0x{symbol.offset:04X} size=0x{symbol.size:04X} align=0x{symbol.align:X} {symbol.name}"
)
if not bss_section.pointers:
raise FixBssException(f"No pointers to BSS found in ROM for {file}")
base_bss_symbols = determine_base_bss_ordering(build_bss_symbols, bss_section)
print("Baserom BSS ordering:")
for symbol in base_bss_symbols:
print(
f" offset=0x{symbol.offset:04X} size=0x{symbol.size:04X} align=0x{symbol.align:X} {symbol.name}"
)
pragmas = find_pragmas(symbol_table)
max_pragmas = 3
if not pragmas:
raise FixBssException(f"No increment_block_number pragmas found in {file}")
elif len(pragmas) > max_pragmas:
raise FixBssException(
f"Too many increment_block_number pragmas found in {file} (found {len(pragmas)}, max {max_pragmas})"
)
print("Solving BSS ordering ...")
new_pragmas = solve_bss_ordering(pragmas, bss_variables, base_bss_symbols)
print("New increment_block_number amounts:")
for pragma in new_pragmas:
print(f" line {pragma.line_number}: {pragma.amount}")
if not dry_run:
update_source_file(version, file, new_pragmas)
print(f"{colorama.Fore.GREEN}Updated {file}{colorama.Fore.RESET}")
def process_file_worker(*x):
# Collect output in a buffer to avoid interleaving output when processing multiple files
old_stdout = sys.stdout
fake_stdout = io.StringIO()
try:
sys.stdout = fake_stdout
process_file(*x)
except FixBssException as e:
# exception with a message for the user
print(f"{colorama.Fore.RED}Error: {str(e)}{colorama.Fore.RESET}")
raise
except Exception as e:
# "unexpected" exception, also print a trace for devs
print(f"{colorama.Fore.RED}Error: {str(e)}{colorama.Fore.RESET}")
traceback.print_exc(file=sys.stdout)
raise
finally:
sys.stdout = old_stdout
print()
print(fake_stdout.getvalue(), end="")
def main():
parser = argparse.ArgumentParser(
description="Automatically fix BSS ordering by editing increment_block_number pragmas. "
"Assumes that the build is up-to-date and that only differences between the baserom and "
"the current build are due to BSS ordering."
)
parser.add_argument(
"--oot-version",
"-v",
type=str,
required=True,
help="OOT version",
)
parser.add_argument(
"--dry-run",
action="store_true",
help="Print changes instead of editing source files",
)
parser.add_argument(
"files",
metavar="FILE",
nargs="*",
type=Path,
help="Fix BSS ordering for a particular C file (default: all files with BSS differences)",
)
args = parser.parse_args()
version = args.oot_version
bss_sections = compare_pointers(version)
files_with_reordering = []
for file, bss_section in bss_sections.items():
if not bss_section.pointers:
continue
# Try to detect if the section is shifted by comparing the lowest
# address among any pointer into the section between base and build
base_min_address = min(p.base_value for p in bss_section.pointers)
build_min_address = min(p.build_value for p in bss_section.pointers)
if not all(
p.build_value - build_min_address == p.base_value - base_min_address
for p in bss_section.pointers
):
files_with_reordering.append(file)
if files_with_reordering:
print("Files with BSS reordering:")
for file in files_with_reordering:
print(f" {file}")
else:
print("No BSS reordering found.")
if args.files:
files_to_fix = args.files
else:
files_to_fix = files_with_reordering
if not files_to_fix:
return
print(f"Running make to find compiler command line ...")
make_log = generate_make_log(version)
with multiprocessing.Pool() as p:
file_results = []
for file in files_to_fix:
file_result = p.apply_async(
process_file_worker,
(
file,
bss_sections[file],
make_log,
args.dry_run,
version,
),
)
file_results.append(file_result)
# Wait until all files are done
while not all(file_result.ready() for file_result in file_results):
time.sleep(0.010)
# Collect results and check for errors
num_successes = sum(file_result.successful() for file_result in file_results)
if num_successes == len(file_results):
print()
print(f"Updated {num_successes}/{len(file_results)} files.")
else:
print()
print(
f"{colorama.Fore.RED}Updated {num_successes}/{len(file_results)} files.{colorama.Fore.RESET}"
)
sys.exit(1)
if __name__ == "__main__":
main()