refactor.py

#!/usr/bin/env python3

""" Access checker script.

This script checks that WiredTiger sources comply with modularity rules
described in MODULARITY.md.

"""

import sys, os
import itertools
from dataclasses import dataclass, field

# layercparse is a library written and maintained by the WiredTiger team.
import regex
from layercparse import *
import wt_defs

_globals: Codebase

class Patcher:
    txt = ""
    patch_list: list[tuple[tuple[int, int], int, str]]
    idx = 0  # this is used to order the patches for the same range

    def __init__(self, txt: str):
        self.txt = txt
        self.patch_list = []

    @staticmethod
    def fromFile(fname: str) -> 'Patcher':
        return Patcher(file_content(fname))

    def replace(self, range_: tuple[int, int], txt: str) -> None:
        self.idx += 1
        self.patch_list.append((range_, self.idx, txt))

    def __bool__(self) -> bool:
        return bool(self.patch_list)

    def get_patched(self) -> str:
        ret: list[str] = []
        self.patch_list.sort()
        pos = 0
        for patch in self.patch_list:
            if patch[0][0] > pos:
                ret.append(self.txt[pos:patch[0][0]])
            ret.append(patch[2])
            pos = patch[0][1]
        ret.append(self.txt[pos:])
        return "".join(ret)

_patchers: dict[str, Patcher]  # file -> Patcher

def _get_patcher_for_file(fname: str) -> Patcher:
    if fname not in _patchers:  # type: ignore[attr-defined]
        _patchers[fname] = Patcher.fromFile(fname)  # type: ignore[attr-defined]
    return _patchers[fname]  # type: ignore[attr-defined]

def renameFields(renames: dict[str, dict[str, str]]) -> None:
    access_chain: AccessChain

    def on_field_chain(arg: AccessFieldChain):
        nonlocal access_chain
        access_chain = arg.chain

    def on_field_access(arg: AccessField):
        t = _globals.untypedef(arg.typename)
        if t not in renames or arg.field not in renames[t]:
            return
        body = cast(Token, arg.src.details.body)  # type: ignore[union-attr] # arg.src.details.body
        rng = rangeShift(arg.range, body.range[0])
        fname = arg.src.scope.file.name
        patcher = _get_patcher_for_file(fname)
        txt = patcher.txt
        if body.value[arg.range[0]:arg.range[1]] != arg.field or arg.field != txt[rng[0]:rng[1]]:
            LOG(LogLevel.QUIET, lambda:arg.src.scope.locationStr(rng[0]), f"Field access mismatch in {arg.src.name}: <{arg.field}> == <{body.value[arg.range[0]:arg.range[1]]}> == <{txt[rng[0]:rng[1]]}>")
            return None
        print(f"{arg.src.scope.locationStr(rng[0])} Field access in {arg.src.name}: {access_chain}: {t}:{arg.field} -> {renames[t][arg.field]}")
        patcher.replace(rng, renames[t][arg.field])
        return None

    access = AccessCheck(_globals)
    fields_re = regex.compile(r"\b(?:\L<names>)\b", re_flags, names=[v for vv in renames.values() for v in vv.keys()])
    for defn in itertools.chain(_globals.names.values(),
                                (v for vv in _globals.static_names.values() for v in vv.values())):
        if (not defn.details or
                not (body := getattr(defn.details, "body", None)) or
                not body.value or
                not fields_re.search(body.value)
                ):
            continue
        list(access.scan_function(defn, on_field_access=on_field_access, on_field_chain=on_field_chain))

def applyPatches() -> None:
    if not _patchers:
        print("No patches to apply.")
        return
    print("Applying patches:")
    total = 0
    for fname, patcher in _patchers.items():
        if patcher:
            total += len(patcher.patch_list)
            print(f"{fname}: Applying {len(patcher.patch_list)} patches.")
            with open(fname, "w") as f:
                f.write(patcher.get_patched())
    print(f"Total patches applied: {total}")

def main():
    global _globals, _patchers
    _patchers = {}

    if len(sys.argv) < 3:
        print("Usage: refactor.py <path> <script>")
        return 1

    refactor_prog = file_content(sys.argv[2])

    setLogLevel(LogLevel.FATAL)
    Log.module_name_mismatch.enabled = False

    rootPath = os.path.realpath(sys.argv[1])
    setRootPath(rootPath)
    setModules(wt_defs.modules)

    files = get_files()  # list of all source files
    for file in wt_defs.extraFiles:
        files.insert(0, os.path.join(os.path.realpath(rootPath), file))

    _globals = Codebase()
    # print(" ===== Scan")
    for macro in wt_defs.extraMacros:
        _globals.addMacro(**macro)
    _globals.scanFiles(files, twopass=False)

    # Pretend that typed macros are functions
    for macrodef in _globals.macros.values():
        macro = cast(MacroParts, macrodef.details)
        if macro.get_has_rettype() and macro.name.value not in _globals.names:
            _globals.names[macro.name.value] = macrodef

    exec(refactor_prog)
    applyPatches()

    return not workspace.errors

if __name__ == "__main__":
    try:
        sys.exit(main())
    except (KeyboardInterrupt, BrokenPipeError):
        print("\nInterrupted")
        sys.exit(1)
    except OSError as e:
        print(f"\n{e.strerror}: {e.filename}")
        sys.exit(1)