Files
libretro/scripts/scraper/shell_launchers.py
T
Abdessamad Derraz 57af8e4921 feat: read ROCKNIX launchers from its packages
The scraper reads the start scripts and the configs each package installs at the tag the BIOS list is pinned to: configs that name a BIOS path, the yabasanshiro search, directories handed to DuckStation and the PCSX2 builds, and the ln -s commands that put bios/ where an emulator reads. A package that ships one config per device gets a device field only where the values differ, as melonDS does on AMD64.
2026-10-20 20:45:19 +02:00

532 lines
19 KiB
Python

"""Readers for launchers written as shell scripts and key=value configs.
ROCKNIX and EmuDeck launch emulators from bash: a start script links or
writes a BIOS path, a config shipped with the package names the file. These
helpers read that text without running it. Each one targets a construct
(an assignment, a for loop, an ln command, a key of a config) and the
extractors built on them raise LauncherPatternMissing when the construct is
gone, so a rewrite upstream stops the scrape instead of publishing nothing.
"""
from __future__ import annotations
import json
import re
from collections.abc import Callable, Iterable
from dataclasses import dataclass, field
try:
from .base_scraper import fetch_bytes, github_headers
from .batocera_launchers import LauncherShapeError
except ImportError:
from base_scraper import fetch_bytes, github_headers
from batocera_launchers import LauncherShapeError
NAME = r"[A-Za-z_][A-Za-z0-9_]*"
# A single-quoted "$" is literal: it is carried as this mark through expansion.
LITERAL_DOLLAR = "\x00"
# A loop variable expands to this mark around its name, so the caller can
# tell which part of a path the loop supplies.
LOOP_MARK = "\x01"
class LauncherPatternMissing(LauncherShapeError):
"""A construct an extractor reads is absent from the launcher source."""
def __init__(self, path: str, what: str) -> None:
super().__init__(f"{path}: {what} not found")
def span(first: int, last: int) -> str:
return str(first) if first == last else f"{first}-{last}"
def merge_lines(lines: Iterable[int]) -> list[tuple[int, int]]:
"""Line numbers as sorted spans, a gap of one line joined."""
spans: list[tuple[int, int]] = []
for line in sorted(set(lines)):
if spans and line <= spans[-1][1] + 2:
spans[-1] = (spans[-1][0], line)
else:
spans.append((line, line))
return spans
def source_ref(parts: Iterable[tuple[str, Iterable[int]]]) -> str:
"""path:a-b, c for each file, files in the order given."""
merged: dict[str, set[int]] = {}
for path, lines in parts:
merged.setdefault(path, set()).update(lines)
return ", ".join(
f"{path}:{', '.join(span(*s) for s in merge_lines(lines))}"
for path, lines in merged.items()
)
@dataclass
class Word:
"""A shell word: as written, and with quotes removed."""
raw: str
text: str
def words(line: str) -> list[Word]:
"""The words of one command line, quotes removed, comments dropped.
Variables are left unexpanded, each written ${NAME} so the quoting that
ended a name ("$a""b") still ends it. A "$" inside single quotes is kept
as LITERAL_DOLLAR so a later expansion leaves it alone.
"""
result: list[Word] = []
raw, text, quote, started, segment = "", "", "", False, 0
def close_segment() -> None:
nonlocal text, segment
text = text[:segment] + re.sub(rf"\$({NAME})", r"${\1}", text[segment:])
segment = len(text)
i = 0
while i < len(line):
char = line[i]
if quote == "'":
raw += char
if char == "'":
quote = ""
segment = len(text)
else:
text += LITERAL_DOLLAR if char == "$" else char
elif quote == '"':
raw += char
if char == "\\" and i + 1 < len(line) and line[i + 1] in '"\\$`':
raw += line[i + 1]
text += LITERAL_DOLLAR if line[i + 1] == "$" else line[i + 1]
i += 1
elif char == '"':
quote = ""
close_segment()
else:
text += char
elif char in "'\"":
close_segment()
quote, started = char, True
raw += char
elif char == "\\" and i + 1 < len(line):
raw += char + line[i + 1]
text += line[i + 1]
started = True
i += 1
elif char == "#" and not started:
break
elif char.isspace() or char == ";":
if started:
close_segment()
result.append(Word(raw, text))
raw, text, started, segment = "", "", False, 0
if char == ";":
result.append(Word(";", ";"))
else:
raw += char
text += char
started = True
i += 1
if started:
close_segment()
result.append(Word(raw, text))
return result
@dataclass
class Assignment:
line: int
value: str
@dataclass
class Loop:
"""A for loop: its variable, its items and the lines they come from."""
var: str
items: list[str]
start: int
end: int
lines: set[int] = field(default_factory=set)
@dataclass
class Link:
"""An ln -s whose link or target lies under the BIOS root."""
target: str
link: str
bios_side: str
names: list[str]
lines: set[int]
bios_is_target: bool = True
expands: dict[str, list[str]] = field(default_factory=dict)
def _placeholders(text: str, marks: dict[str, Loop]) -> str:
"""Loop marks written as {VAR}, the placeholder `expands` resolves."""
for mark, loop in marks.items():
text = text.replace(mark, "{" + loop.var + "}")
return text
class Script:
"""One shell script or makefile, read line by line."""
def __init__(self, path: str, text: str) -> None:
self.path = path
self.text = text
self.lines = text.splitlines()
self._assignments: dict[str, list[Assignment]] = {}
self._arrays: dict[str, tuple[int, list[str]]] = {}
for number, line in enumerate(self.lines, 1):
found = re.match(rf"\s*(?:local\s+|export\s+)?({NAME})=(.*)$", line)
if found is None:
continue
array = re.fullmatch(r"\((.*)\)\s*", found.group(2))
if array:
self._arrays[found.group(1)] = (number, [w.text for w in words(array.group(1))])
continue
value = words(found.group(2))
if value and value[0].raw:
self._assignments.setdefault(found.group(1), []).append(
Assignment(number, value[0].text)
)
def missing(self, what: str) -> LauncherPatternMissing:
return LauncherPatternMissing(self.path, what)
def code(self) -> Iterable[tuple[int, str]]:
"""Lines that are not comments."""
for number, line in enumerate(self.lines, 1):
if not line.lstrip().startswith("#"):
yield number, line
def find(
self, pattern: str, what: str, start: int = 1, end: int | None = None
) -> tuple[int, re.Match[str]]:
"""The first code line from start to end matching pattern."""
for number, line in self.code():
if number < start or (end is not None and number > end):
continue
found = re.search(pattern, line)
if found:
return number, found
raise self.missing(what)
def assignment_ending(self, suffix: str) -> Assignment | None:
"""The first assignment whose value ends with suffix."""
return next(
(a for found in self._assignments.values() for a in found if a.value.endswith(suffix)),
None,
)
def value(self, name: str, before: int) -> Assignment | None:
"""The last assignment of name above a line, else the first below it."""
assignments = self._assignments.get(name, [])
above = [a for a in assignments if a.line < before]
if above:
return above[-1]
return assignments[0] if assignments else None
def expand(
self, text: str, line: int, used: set[int], fixed: dict[str, str] | None = None
) -> str:
"""Variables replaced by their assigned value, unknown ones as ${NAME}."""
fixed = fixed or {}
def replace(found: re.Match[str], depth: int) -> str:
name = found.group(1) or found.group(2)
if name in fixed:
return fixed[name]
assignment = self.value(name, line)
if assignment is None or depth > 8:
return "${" + name + "}"
used.add(assignment.line)
return expand_once(assignment.value, assignment.line, depth + 1)
def expand_once(value: str, at: int, depth: int) -> str:
nonlocal line
saved, line = line, at
try:
return re.sub(rf"\$\{{({NAME})\}}|\$({NAME})", lambda m: replace(m, depth), value)
finally:
line = saved
return expand_once(text, line, 0).replace(LITERAL_DOLLAR, "$")
def loops(self) -> list[Loop]:
"""Every for loop, items from a word list or from "${ARRAY[@]}"."""
found_loops = []
for number, line in self.code():
head = re.match(rf"\s*for ({NAME}) in (.*?)\s*(?:;\s*do)?\s*$", line)
if head is None:
continue
items = [w.text for w in words(head.group(2)) if w.text != ";"]
lines = {number}
if len(items) == 1 and (array := re.fullmatch(rf"\$\{{({NAME})\[@\]\}}", items[0])):
if array.group(1) not in self._arrays:
raise self.missing(f"array {array.group(1)}")
array_line, items = self._arrays[array.group(1)]
lines.add(array_line)
found_loops.append(Loop(head.group(1), items, number, self._loop_end(number), lines))
return found_loops
def _loop_end(self, start: int) -> int:
depth = 0
for number, line in self.code():
if number < start:
continue
if re.match(r"\s*(for|while|until)\b", line):
depth += 1
if re.match(r"\s*done\b", line) or re.search(r";\s*done\s*$", line):
depth -= 1
if depth == 0:
return number
raise self.missing(f"done of the loop at line {start}")
def links(self, bios_root: str, fixed: dict[str, str] | None = None) -> list[Link]:
"""ln -s commands with the link or its target under bios_root.
Links in one loop, or written one by one as P/n linked to Q/n, are
one Link listing each n.
"""
loops = self.loops()
found: list[Link] = []
for number, line in self.code():
command = words(line)
heads = [
i
for i, w in enumerate(command)
if w.raw == "ln"
and (i == 0 or command[i - 1].raw in {";", "then", "do", "&&", "||"})
]
for head in heads:
args = []
for word in command[head + 1 :]:
if word.raw in {";", "&&", "||"}:
break
args.append(word)
options = [w.text for w in args if w.text.startswith("-")]
operands = [w.text for w in args if not w.text.startswith("-")]
if not any("s" in o for o in options) or len(operands) != 2:
continue
enclosing = [lp for lp in loops if lp.start < number <= lp.end]
env = dict(fixed or {})
marks = {f"{LOOP_MARK}{lp.var}{LOOP_MARK}": lp for lp in enclosing}
env.update({lp.var: mark for mark, lp in marks.items()})
used = {number}
target, link = (self.expand(op, number, used, env) for op in operands)
if not (_under(target, bios_root) or _under(link, bios_root)):
continue
bios_is_target = _under(target, bios_root)
bios_side = (target if bios_is_target else link).rstrip("/")
folder, _, last = bios_side.rpartition("/")
present = [m for m in marks if m in target or m in link]
if any(m in folder for m in present):
raise self.missing(
f"loop variable only in the last segment of the ln at line {number}"
)
names: list[str] = []
expands: dict[str, list[str]] = {}
if present:
bios_side = folder
if last in marks:
names = list(marks[last].items)
else:
names = [_placeholders(last, marks)]
expands = {lp.var: list(lp.items) for m, lp in marks.items() if m in last}
if bios_is_target and last not in link:
link = f"{link.rstrip('/')}/{last}"
for mark in present:
used |= marks[mark].lines
template = _placeholders(last, marks) if expands else "<name>"
target, link = (
p.replace(last, template) if last in p else _placeholders(p, marks)
for p in (target, link)
)
duplicate = next((f for f in found if (f.target, f.link) == (target, link)), None)
if duplicate is not None:
duplicate.lines |= used
continue
found.append(Link(target, link, bios_side, names, used, bios_is_target, expands))
return _merge_links(found)
def _under(path: str, root: str) -> bool:
return path.rstrip("/") == root.rstrip("/") or path.startswith(root.rstrip("/") + "/")
def _merge_links(links: list[Link]) -> list[Link]:
"""Single links P/n -> Q/n sharing P and Q folded into one, names in order."""
merged: list[Link] = []
folds: dict[tuple[str, str, bool], tuple[Link, list[Link]]] = {}
for link in links:
bios = link.bios_side.rstrip("/")
bios_is_target = link.bios_is_target
other = (link.link if bios_is_target else link.target).rstrip("/")
name = bios.rsplit("/", 1)[-1]
if link.names or other.rsplit("/", 1)[-1] != name:
merged.append(link)
continue
key = (bios.rsplit("/", 1)[0], other.rsplit("/", 1)[0], bios_is_target)
if key in folds:
folds[key][1].append(link)
else:
folds[key] = (link, [link])
merged.append(link)
folded: set[int] = set()
for (parent, other_parent, bios_is_target), (first, members) in folds.items():
if len(members) == 1:
continue
first.names = [m.bios_side.rstrip("/").rsplit("/", 1)[-1] for m in members]
first.bios_side = parent
bios_end, other_end = f"{parent}/<name>", f"{other_parent}/<name>"
first.target, first.link = (
(bios_end, other_end) if bios_is_target else (other_end, bios_end)
)
for member in members[1:]:
first.lines |= member.lines
folded.add(id(member))
return [link for link in merged if id(link) not in folded]
@dataclass
class Setting:
section: str
key: str
value: str
line: int
def settings(text: str, separator: str = "=") -> list[Setting]:
"""key = value lines under their [section], quotes around the value removed.
separator " " reads mednafen's "key value" form.
"""
found, section = [], ""
for number, line in enumerate(text.splitlines(), 1):
stripped = line.strip()
if not stripped or stripped[0] in "#;":
continue
header = re.fullmatch(r"\[([^\]]+)\]", stripped)
if header:
section = header.group(1)
continue
if separator == " ":
pair = re.fullmatch(r"(\S+)(?:\s+(.*))?", stripped)
else:
pair = re.fullmatch(r"([^=\s]+)\s*=\s*(.*)", stripped)
if pair is None:
continue
value = (pair.group(2) or "").strip()
if len(value) >= 2 and value[0] == value[-1] and value[0] in "\"'":
value = value[1:-1]
found.append(Setting(section, pair.group(1), value, number))
return found
def describe_keys(file: str, keys: tuple[tuple[str, str], ...]) -> str:
"""file [section] key, key [other] key, sections named where they change."""
described, section = file, None
for index, (key_section, key) in enumerate(keys):
if key_section and key_section != section:
described += f" [{key_section}] {key}"
section = key_section
else:
described += (" " if index == 0 else ", ") + key
return described
@dataclass
class Entry:
"""A directory entry: kind is "dir", "file" or "link"."""
kind: str
target: str = ""
class RepoTree:
"""Files of one repository revision, read on demand and kept."""
def __init__(
self,
read: Callable[[str], str],
listdir: Callable[[str], dict[str, Entry]],
) -> None:
self._read = read
self._listdir = listdir
self._texts: dict[str, str] = {}
self._dirs: dict[str, dict[str, Entry]] = {}
def read(self, path: str) -> str:
if path not in self._texts:
self._texts[path] = self._read(path)
return self._texts[path]
def listdir(self, path: str) -> dict[str, Entry]:
if path not in self._dirs:
self._dirs[path] = self._listdir(path)
return self._dirs[path]
def has(self, path: str) -> bool:
parent, _, name = path.rpartition("/")
try:
return name in self.listdir(parent)
except LauncherPatternMissing:
return False
@classmethod
def from_files(cls, files: dict[str, str], links: dict[str, str] | None = None) -> RepoTree:
"""A tree held in memory: file texts by path, symlink targets by path."""
links = links or {}
def read(path: str) -> str:
if path not in files:
raise LauncherPatternMissing(path, "file")
return files[path]
def listdir(path: str) -> dict[str, Entry]:
prefix = path.rstrip("/") + "/"
entries: dict[str, Entry] = {}
for name, target in links.items():
if name.startswith(prefix) and "/" not in name[len(prefix) :]:
entries[name[len(prefix) :]] = Entry("link", target)
for name in files:
if name.startswith(prefix):
rest = name[len(prefix) :]
head, _, tail = rest.partition("/")
entries.setdefault(head, Entry("dir" if tail else "file"))
if not entries:
raise LauncherPatternMissing(path, "directory")
return entries
return cls(read, listdir)
@classmethod
def github(cls, repo: str, rev: str) -> RepoTree:
"""A GitHub repository at one revision: raw files and the trees API."""
def read(path: str) -> str:
url = f"https://raw.githubusercontent.com/{repo}/{rev}/{path}"
return fetch_bytes(url).decode("utf-8-sig")
def listdir(path: str) -> dict[str, Entry]:
url = f"https://api.github.com/repos/{repo}/git/trees/{rev}:{path}"
try:
listing = json.loads(fetch_bytes(url, headers=github_headers()))
except ConnectionError as e:
raise LauncherPatternMissing(path, f"directory ({e})") from e
entries = {}
for item in listing.get("tree", []):
if item["mode"] == "120000":
entries[item["path"]] = Entry("link", read(f"{path}/{item['path']}").strip())
else:
entries[item["path"]] = Entry("dir" if item["type"] == "tree" else "file")
return entries
return cls(read, listdir)