7f8a81b8f8
The generator had not been able to run correctly since the manual moved into
`tools/ppc-manual/`: it computed the repository root as `HERE.parent.parent`,
which now names `tools/`, so the XML, Canary's emitters and xenia-rs all stopped
resolving — silently, because both scrapers skipped what they could not find.
Every page's references had been pointing at paths that exist nowhere.
What each source contributed, measured on the 350 pages before this change:
Operation (pseudocode) 251 pages: fixed boilerplate "derives from the xenia-rs
interpreter"; 99 carry real hand-written seeds
C translation 337 pages: the same kind of boilerplate
xenia-rs snapshot 336 pages: the interpreter arm, pasted in — the only
per-instruction semantics on unseeded pages
links xenia-rs opcode/decoder/interpreter + Canary emitter
Now:
* semantics come from **Xenia Canary**, the reference emulator, read through
`git show` at a pinned upstream commit (`origin/canary_experimental`,
f21ebd49e9). Not our checkout: it carries instrumentation and lacked
upstream's `mcrf` fix, so it would have published probes and a wrong `mcrf`.
Each page embeds the emitter (`InstrEmit_<mnem>`), and for the 128 pure
one-line delegations also the helper that holds the semantics.
* decode references point at `crates/sylpheed-ppc` — the decoder that
produces `sylpheed.db` — as in-repo relative links.
* the boilerplate now says what is true, and the C translation guide maps
Canary's actual HIR calls, checked against `ppc_hir_builder.h` (including
that `UpdateCR(n, v)` truncates to 32 bits).
* `rust_scraper.py` -> `decoder_scraper.py` (interpreter half dropped);
missing sources are now errors, not empty results.
Verified:
consistency checks 455 XML entries, 350 families, 598 index keys
hand-written tails 386/386 byte-identical after regeneration
xenia-rs in generated 0
pages with a snapshot 349/350 (was 336) — `dcbi` has no Canary emitter at all
in-repo decoder links 910/910 resolve to a line holding the identifier
emitter boundaries brace counter == column-0 `}` rule on 521/521;
preprocessor model unit-tested (#if 0/#else/#elif)
idempotency re-run: 0 pages updated, 0 working-tree changes
Hand-written notes (outside the generated regions) are not rewritten here:
* 110 links into `../../xenia-rs/...` were dead; they now point at the file in
the archived repository (git.mc02.dev/fabi/xenia-rs @ 8401d4d). Line anchors
were dropped because the notes predate that commit — 0 of 441 old line
ranges match it — and a precise-looking wrong anchor is worse than none. The
link text, which carries the author's line numbers, is unchanged.
* 140 prose claims about xenia-rs's behaviour remain. 23 are verified to hold
for Canary too (the 32-bit CR0 truncation, OE left unimplemented); the other
114 need checking one by one, and some invert — e.g. `divdx` notes a correct
64-bit CR0 update in xenia-rs where Canary's `UpdateCR` truncates. Left for
a deliberate pass rather than a blind substitution.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
105 lines
4.0 KiB
Python
105 lines
4.0 KiB
Python
"""
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Locates each instruction in Sylpheed's own PowerPC decoder,
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`crates/sylpheed-ppc` — the decoder that produces the disassembly in
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`sylpheed.db`, and so the one whose mnemonics a reader of that database sees.
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Outputs produced for each mnemonic:
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- opcode_line: line in `crates/sylpheed-ppc/src/opcode.rs` where the
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`PpcOpcode` variant is declared (1-indexed)
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- decoder_line: line in `crates/sylpheed-ppc/src/decoder.rs` where the
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variant is produced from raw bits
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This used to scrape `xenia-rs/crates/xenia-cpu/src/`, including an
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interpreter-arm snapshot. `xenia-rs` is retired and archived, and the decoder
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half was lifted into `sylpheed-ppc` unchanged in shape — the same
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`pub enum PpcOpcode` and `PpcOpcode::<name>` producers — so only the path and
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the interpreter half changed. Semantics now come from Canary; see
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`cxx_scraper.py`.
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🔴 Missing sources are an error, not an empty index. The previous version
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returned `[]` for a file it could not find, so once the manual moved and the
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path stopped resolving, every page silently lost its references.
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"""
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from __future__ import annotations
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from dataclasses import dataclass
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from pathlib import Path
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import re
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DECODER_CRATE = Path("crates") / "sylpheed-ppc" / "src"
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@dataclass
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class DecoderRef:
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mnem: str
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opcode_line: int | None = None
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decoder_line: int | None = None
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def _ident(mnem: str) -> str:
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"""XML mnemonic -> `PpcOpcode` variant: `.` is not legal in a Rust
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identifier, so `addic.` is `addicx` (the same rule Canary uses)."""
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return mnem.replace(".", "x")
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class DecoderScraper:
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def __init__(self, repo_root: Path):
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self.src = repo_root / DECODER_CRATE
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self._opcode_lines = self._read_lines(self.src / "opcode.rs")
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self._decoder_lines = self._read_lines(self.src / "decoder.rs")
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self._opcode_index = self._index_opcode_enum()
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self._decoder_index = self._index_decoder()
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if not self._opcode_index or not self._decoder_index:
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raise SystemExit(f"no PpcOpcode variants/producers found under {self.src}")
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@staticmethod
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def _read_lines(path: Path) -> list[str]:
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if not path.is_file():
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raise SystemExit(f"decoder source missing: {path}")
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return path.read_text(encoding="utf-8").splitlines()
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def _index_opcode_enum(self) -> dict[str, int]:
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"""Map identifier -> 1-indexed line inside `pub enum PpcOpcode { ... }`
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(several identifiers may share a line)."""
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idx: dict[str, int] = {}
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token = re.compile(r"\b([A-Za-z_][A-Za-z0-9_]*)\b")
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in_enum = False
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for i, line in enumerate(self._opcode_lines, start=1):
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if "pub enum PpcOpcode" in line:
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in_enum = True
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continue
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if not in_enum:
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continue
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if line.startswith("}"):
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break
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code = line.strip().split("//", 1)[0]
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for m in token.finditer(code):
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idx.setdefault(m.group(1), i)
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return idx
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def _index_decoder(self) -> dict[str, int]:
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"""Map identifier -> 1-indexed line of its FIRST `PpcOpcode::<name>`
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occurrence, i.e. where the decoder produces it."""
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idx: dict[str, int] = {}
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pat = re.compile(r"PpcOpcode::([A-Za-z_][A-Za-z0-9_]*)")
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for i, line in enumerate(self._decoder_lines, start=1):
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for m in pat.finditer(line):
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idx.setdefault(m.group(1), i)
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return idx
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def lookup(self, mnem: str) -> DecoderRef:
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ident = _ident(mnem)
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return DecoderRef(mnem=mnem,
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opcode_line=self._opcode_index.get(ident),
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decoder_line=self._decoder_index.get(ident))
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if __name__ == "__main__":
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root = Path(__file__).resolve().parents[3]
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s = DecoderScraper(root)
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for m in ("addcx", "addic.", "lwz", "bclrx", "mfspr", "stvx", "vaddfp",
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"vaddfp128", "faddx", "mcrf"):
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r = s.lookup(m)
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print(f"{m:12s} opcode@{r.opcode_line} decoder@{r.decoder_line}")
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