1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
//! Import and export functionality for MMB binary proof format
//!
//! See [`mm0-c/verifier.c`] for information on the MMB format.
//!
//! [`mm0-c/verifier.c`]: https://github.com/digama0/mm0/blob/master/mm0-c/verifier.c
// rust lints we want
#![warn(
bare_trait_objects,
elided_lifetimes_in_paths,
missing_copy_implementations,
missing_debug_implementations,
future_incompatible,
rust_2018_idioms,
trivial_numeric_casts,
variant_size_differences,
unreachable_pub,
unused,
missing_docs
)]
// all the clippy
#![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
// all the clippy::restriction lints we want
#![warn(
clippy::else_if_without_else,
clippy::float_arithmetic,
clippy::get_unwrap,
clippy::inline_asm_x86_att_syntax,
clippy::integer_division,
clippy::rc_buffer,
clippy::rest_pat_in_fully_bound_structs,
clippy::string_add,
clippy::unwrap_used
)]
// all the clippy lints we don't want
#![allow(
clippy::cognitive_complexity,
clippy::comparison_chain,
clippy::default_trait_access,
clippy::inline_always,
clippy::manual_filter_map,
clippy::map_err_ignore,
clippy::missing_const_for_fn,
clippy::missing_errors_doc,
clippy::missing_panics_doc,
clippy::module_name_repetitions,
clippy::multiple_crate_versions,
clippy::option_if_let_else,
clippy::semicolon_if_nothing_returned,
clippy::shadow_unrelated,
clippy::too_many_lines,
clippy::use_self
)]
mod parser;
mod ty;
mod write;
use std::convert::{TryFrom, TryInto};
use std::ffi::CStr;
use std::mem::size_of;
use byteorder::LE;
use mm0_util::{Modifiers, SortId, TermId, ThmId};
use zerocopy::{AsBytes, FromBytes, Unaligned, U16, U32, U64};
pub use mm0_util::u32_as_usize;
pub use {parser::*, ty::*, write::*};
/// The maximum number of bound variables supported by the MMB format.
pub const MAX_BOUND_VARS: usize = 55;
/// Constants used in the MMB specification.
pub mod cmd {
/// `MM0B_MAGIC = "MM0B"`: Magic number signalling the MM0B format is in use.
pub const MM0B_MAGIC: [u8; 4] = *b"MM0B";
/// `MM0B_VERSION = 1`, maximum supported MMB version
pub const MM0B_VERSION: u8 = 1;
/// `DATA_8 = 0x40`, used as a command mask for an 8 bit data field
pub const DATA_8: u8 = 0x40;
/// `DATA_16 = 0x80`, used as a command mask for a 16 bit data field
pub const DATA_16: u8 = 0x80;
/// `DATA_32 = 0xC0`, used as a command mask for a 32 bit data field
pub const DATA_32: u8 = 0xC0;
/// `DATA_MASK = 0xC0`, selects one of `DATA_8`, `DATA_16`, or `DATA_32` for data size
pub const DATA_MASK: u8 = 0xC0;
/// `STMT_AXIOM = 0x02`, starts an `axiom` declaration
pub const STMT_AXIOM: u8 = 0x02;
/// `STMT_SORT = 0x04`, starts a `sort` declaration
pub const STMT_SORT: u8 = 0x04;
/// `STMT_TERM = 0x05`, starts a `term` declaration
pub const STMT_TERM: u8 = 0x05;
/// `STMT_DEF = 0x05`, starts a `def` declaration. (This is the same as
/// `STMT_TERM` because the actual indication of whether this is a
/// def is in the term header)
pub const STMT_DEF: u8 = 0x05;
/// `STMT_THM = 0x06`, starts a `theorem` declaration
pub const STMT_THM: u8 = 0x06;
/// `STMT_LOCAL = 0x08`, starts a `local` declaration
/// (a bit mask to be combined with `STMT_THM` or `STMT_DEF`)
pub const STMT_LOCAL: u8 = 0x08;
/// `STMT_LOCAL_DEF = 0x0D`
pub const STMT_LOCAL_DEF: u8 = STMT_LOCAL | STMT_DEF;
/// `STMT_LOCAL_THM = 0x0E`
pub const STMT_LOCAL_THM: u8 = STMT_LOCAL | STMT_THM;
/// `PROOF_TERM = 0x10`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_TERM: u8 = 0x10;
/// `PROOF_TERM_SAVE = 0x11`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_TERM_SAVE: u8 = 0x11;
/// `PROOF_REF = 0x12`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_REF: u8 = 0x12;
/// `PROOF_DUMMY = 0x13`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_DUMMY: u8 = 0x13;
/// `PROOF_THM = 0x14`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_THM: u8 = 0x14;
/// `PROOF_THM_SAVE = 0x15`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_THM_SAVE: u8 = 0x15;
/// `PROOF_HYP = 0x16`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_HYP: u8 = 0x16;
/// `PROOF_CONV = 0x17`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_CONV: u8 = 0x17;
/// `PROOF_REFL = 0x18`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_REFL: u8 = 0x18;
/// `PROOF_SYMM = 0x19`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_SYMM: u8 = 0x19;
/// `PROOF_CONG = 0x1A`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_CONG: u8 = 0x1A;
/// `PROOF_UNFOLD = 0x1B`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_UNFOLD: u8 = 0x1B;
/// `PROOF_CONV_CUT = 0x1C`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_CONV_CUT: u8 = 0x1C;
/// `PROOF_CONV_SAVE = 0x1E`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_CONV_SAVE: u8 = 0x1E;
/// `PROOF_SAVE = 0x1F`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_SAVE: u8 = 0x1F;
/// `PROOF_SORRY = 0x20`: See [`ProofCmd`](super::ProofCmd).
pub const PROOF_SORRY: u8 = 0x20;
/// `UNIFY_TERM = 0x30`: See [`UnifyCmd`](super::UnifyCmd).
pub const UNIFY_TERM: u8 = 0x30;
/// `UNIFY_TERM_SAVE = 0x31`: See [`UnifyCmd`](super::UnifyCmd).
pub const UNIFY_TERM_SAVE: u8 = 0x31;
/// `UNIFY_REF = 0x32`: See [`UnifyCmd`](super::UnifyCmd).
pub const UNIFY_REF: u8 = 0x32;
/// `UNIFY_DUMMY = 0x33`: See [`UnifyCmd`](super::UnifyCmd).
pub const UNIFY_DUMMY: u8 = 0x33;
/// `UNIFY_HYP = 0x36`: See [`UnifyCmd`](super::UnifyCmd).
pub const UNIFY_HYP: u8 = 0x36;
/// `"Name"` is the magic number for the name table.
pub const INDEX_NAME: [u8; 4] = *b"Name";
/// `"VarN"` is the magic number for the variable name table.
pub const INDEX_VAR_NAME: [u8; 4] = *b"VarN";
/// `"HypN"` is the magic number for the hypothesis name table.
pub const INDEX_HYP_NAME: [u8; 4] = *b"HypN";
}
#[inline]
fn u64_as_usize(n: U64<LE>) -> usize {
n.get().try_into().expect("here's a nickel, get a better computer")
}
/// Construct a `&`[`CStr`] from a prefix byte slice, by terminating at
/// the first nul character. The second output is the remainder of the slice.
#[must_use]
pub fn cstr_from_bytes_prefix(bytes: &[u8]) -> Option<(&CStr, &[u8])> {
let mid = memchr::memchr(0, bytes)? + 1;
unsafe {
Some((
CStr::from_bytes_with_nul_unchecked(bytes.get_unchecked(..mid)),
bytes.get_unchecked(..mid),
))
}
}
/// The main part of the proof consists of a sequence of declarations,
/// and these commands denote the different kind of declaration that can
/// be introduced.
#[derive(Debug, Clone, Copy)]
pub enum StmtCmd {
/// A new sort. Equivalent to `sort foo;`. This is followed by no data,
/// as the sort data is stored in the header.
Sort,
/// A new axiom. Equivalent to `axiom foo ...`. This is followed by a proof
/// sequence, that should unify with the unify sequence in the header.
Axiom,
/// A new term or def. Equivalent to `term/def foo ...`.
/// If `local` is true, then this is `local def foo`. This is followed by
/// no data, as the header contains the unify sequence and can be checked on its own.
TermDef {
/// Is this `local def`?
local: bool,
},
/// A new theorem. Equivalent to `(pub) theorem foo ...`, where `local` means
/// that the theorem is not `pub`. This is followed by a proof sequence,
/// that will construct the statement and proof, and should unify
/// with the unify sequence in the header.
Thm {
/// Is this not `pub theorem`?
local: bool,
},
}
// IMO breaking this out is preferred to making the id fields Option<A> in StmtCmd
// because the situations in which you will/won't have the id are known beforehand.
// The only case in which you won't have it is when fishing things out from the index
// with IndexEntryRef::decl
//
/// [`StmtCmd`] aware of its position (represented by a typesafe integer)
/// in the mmb file relative to other declarations.
#[derive(Debug, Clone, Copy)]
pub enum NumdStmtCmd {
/// A new sort. Equivalent to `sort foo;`. This is followed by no data,
/// as the sort data is stored in the header.
Sort {
/// The sort ID, the index into the sort table
sort_id: SortId,
},
/// A new axiom. Equivalent to `axiom foo ...`. This is followed by a proof
/// sequence, that should unify with the unify sequence in the header.
Axiom {
/// The theorem ID, the index into the axiom/theorem table
thm_id: ThmId,
},
/// A new term or def. Equivalent to `term/def foo ...`.
/// If `local` is true, then this is `local def foo`. This is followed by
/// no data, as the header contains the unify sequence and can be checked on its own.
TermDef {
/// The term ID, the index into the term/def table
term_id: TermId,
/// Is this `local def`?
local: bool,
},
/// A new theorem. Equivalent to `(pub) theorem foo ...`, where `local` means
/// that the theorem is not `pub`. This is followed by a proof sequence,
/// that will construct the statement and proof, and should unify
/// with the unify sequence in the header.
Thm {
/// The theorem ID, the index into the axiom/theorem table
thm_id: ThmId,
/// Is this not `pub theorem`?
local: bool,
},
}
impl StmtCmd {
/// Is this a "local" command, i.e. it does not appear in the corresponding MM0 file?
#[must_use]
pub fn is_local(self) -> bool {
match self {
Self::Sort | Self::Axiom => false,
Self::TermDef { local } | Self::Thm { local } => local,
}
}
}
impl NumdStmtCmd {
/// Is this a "local" command, i.e. it does not appear in the corresponding MM0 file?
#[must_use]
pub fn is_local(self) -> bool {
match self {
Self::Sort { .. } | Self::Axiom { .. } => false,
Self::TermDef { local, .. } | Self::Thm { local, .. } => local,
}
}
}
impl std::convert::TryFrom<u8> for StmtCmd {
type Error = ParseError;
fn try_from(cmd: u8) -> Result<Self, Self::Error> {
Ok(match cmd {
cmd::STMT_SORT => StmtCmd::Sort,
cmd::STMT_AXIOM => StmtCmd::Axiom,
cmd::STMT_DEF => StmtCmd::TermDef { local: false },
cmd::STMT_LOCAL_DEF => StmtCmd::TermDef { local: true },
cmd::STMT_THM => StmtCmd::Thm { local: false },
cmd::STMT_LOCAL_THM => StmtCmd::Thm { local: true },
_ => return Err(ParseError::StmtCmdConv(cmd)),
})
}
}
/// A proof command, which acts on a stack machine with the following components:
///
/// * `H: Vec<StackEl>`: a "heap" consisting of indexable elements that can be copied
/// onto the stack using [`Ref`](ProofCmd::Ref)
/// * `S: Stack<StackEl>`: The main stack, which most operations push and pop from.
/// * `HS: Vec<Expr>`: The hypothesis list, which grows only on [`Hyp`](ProofCmd::Hyp)
/// operations and collects the hypotheses of the theorem.
#[derive(Debug, Clone, Copy)]
pub enum ProofCmd {
/// ```text
/// Term t: H; S, e1, ..., en --> H; S, (t e1 .. en)
/// Save: H; S, e --> H, e; S, e
/// TermSave t = Term t; Save:
/// H; S, e1, ..., en --> H, (t e1 .. en); S, (t e1 .. en)
/// ```
///
/// Pop `n` elements from the stack and allocate a new term `t` applied to those
/// expressions. When `save` is used, the new term is also saved to the heap
/// (this is used if the term will ever be needed more than once).
Term {
/// The term to construct
tid: TermId,
/// True if we should save to the heap
save: bool,
},
/// ```text
/// Ref i: H; S --> H; S, Hi
/// ConvRef i: H; S, e1 =?= e2 --> H; S (where Hi is e1 = e2)
/// ```
/// Get the `i`-th heap element.
/// * If it is `e1 = e2`, pop a convertibility obligation `e1 =?= e2`.
/// * Otherwise push it on the stack.
Ref(u32),
/// ```text
/// Dummy s: H; S --> H, x; S, x alloc(x:s)
/// ```
/// Allocate a new variable `x` of sort `s`, and push it to the stack and the heap.
Dummy(SortId),
/// ```text
/// Thm T: H; S, e1, ..., en, e --> H; S', |- e
/// (where Unify(T): S; e1, ... en; e --> S'; H'; .)
/// Save: H; S, |- e --> H, |- e; S, |- e
/// ```
/// Pop `n` elements from the stack and put them on the unify heap, then call the
/// unifier for `T` with `e` as the target. The unifier will pop additional
/// proofs from the stack if the UHyp command is used, and when it is done,
/// the conclusion is pushed as a proven statement.
///
/// When Save is used, the proven statement is also saved to the heap.
Thm {
/// The theorem to apply
tid: ThmId,
/// True if we should save to the heap
save: bool,
},
/// ```text
/// Hyp: HS; H; S, e --> HS, e; H, |- e; S
/// ```
/// This command means that we are finished constructing the expression `e`
/// which denotes a statement, and wish to assume it as a hypothesis.
/// Push `e` to the hypothesis stack, and push `|- e` to the heap.
Hyp,
/// ```text
/// Conv: S, e1, |- e2 --> S, |- e1, e1 =?= e2
/// ```
/// Pop `e1` and `|- e2`, and push `|- e1`, guarded by a convertibility obligation
/// `e1 =?= e2`.
Conv,
/// ```text
/// Refl: S, e =?= e --> S
/// ```
/// Pop a convertibility obligation where the two sides are equal.
Refl,
/// ```text
/// Symm: S, e1 =?= e2 --> S, e2 =?= e1
/// ```
/// Swap the direction of a convertibility obligation.
Sym,
/// ```text
/// Cong: S, (t e1 ... en) =?= (t e1' ... en') --> S, en =?= en', ..., e1 =?= e1'
/// ```
/// Pop a convertibility obligation for two term expressions, and
/// push convertibility obligations for all the parts.
/// The parts are pushed in reverse order so that they are dealt with
/// in declaration order in the proof stream.
Cong,
/// ```text
/// Unfold: S, (t e1 ... en) =?= e', e --> S, e =?= e'
/// (where Unify(t): e1, ..., en; e --> H'; .)
/// ```
/// Pop `e` and `(t e1 ... en) =?= e'` from the stack and run the unifier for `t`
/// (which should be a definition) to make sure that `(t e1 ... en)` unfolds to `e`.
/// Then push `e =?= e'`.
Unfold,
/// ```text
/// ConvCut: S, e1 =?= e2 --> S, e1 = e2, e1 =?= e2
/// ```
/// Pop a convertibility obligation `e1 =?= e2`, and
/// push a convertability assertion `e1 = e2` guarded by `e1 =?= e2`.
ConvCut,
/// ```text
/// ConvSave: H; S, e1 = e2 --> H, e1 = e2; S
/// ```
/// Pop a convertibility proof `e1 = e2` and save it to the heap.
ConvSave,
/// ```text
/// Save: H; S, s --> H, s; S, s
/// ```
/// Save the top of the stack to the heap, without popping it.
Save,
/// ```text
/// Sorry: S, e -> S, |- e
/// ConvSorry: S, e1 =?= e2 -> S
/// ```
/// * Sorry: Pop an expression `e` from the stack, and push `|- e`. This step exists
/// only for debugging purposes and incomplete proofs, it is not a valid step
/// under any circumstances, and verifiers are free to pretend it doesn't exist.
///
/// * ConvSorry: Pop a convertibility obligation `e1 =?= e2`. This reuses the Sorry
/// command, and depends on the type of the head of stack for its behavior.
Sorry,
}
impl std::convert::TryFrom<(u8, u32)> for ProofCmd {
type Error = ParseError;
fn try_from((cmd, data): (u8, u32)) -> Result<Self, Self::Error> {
Ok(match cmd {
cmd::PROOF_TERM => ProofCmd::Term { tid: TermId(data), save: false },
cmd::PROOF_TERM_SAVE => ProofCmd::Term { tid: TermId(data), save: true },
cmd::PROOF_REF => ProofCmd::Ref(data),
cmd::PROOF_DUMMY =>
ProofCmd::Dummy(SortId(data.try_into().map_err(|_| ParseError::ProofCmdConv(cmd, data))?)),
cmd::PROOF_THM => ProofCmd::Thm { tid: ThmId(data), save: false },
cmd::PROOF_THM_SAVE => ProofCmd::Thm { tid: ThmId(data), save: true },
cmd::PROOF_HYP => ProofCmd::Hyp,
cmd::PROOF_CONV => ProofCmd::Conv,
cmd::PROOF_REFL => ProofCmd::Refl,
cmd::PROOF_SYMM => ProofCmd::Sym,
cmd::PROOF_CONG => ProofCmd::Cong,
cmd::PROOF_UNFOLD => ProofCmd::Unfold,
cmd::PROOF_CONV_CUT => ProofCmd::ConvCut,
cmd::PROOF_CONV_SAVE => ProofCmd::ConvSave,
cmd::PROOF_SAVE => ProofCmd::Save,
cmd::PROOF_SORRY => ProofCmd::Sorry,
_ => return Err(ParseError::ProofCmdConv(cmd, data)),
})
}
}
/// Unify commands appear in the header data for a `def` or `axiom`/`theorem`.
/// They are executed by the [`ProofCmd::Thm`] command in order to perform
/// substitutions. The state of the unify stack machine is:
///
/// * `MS: Stack<StackEl>`: The main stack, called `S` in the [`ProofCmd`]
/// documentation.
/// Since a unification is called as a subroutine during a proof command,
/// the main stack is available, but most operations don't use it.
/// * `S: Stack<Expr>`: The unify stack, which contains expressions
/// from the target context that are being destructured.
/// * `H: Vec<Expr>`: The unify heap, also known as the substitution. This is
/// initialized with the expressions that the target context would like to
/// substitute for the variable names in the theorem being applied, but
/// it can be extended in order to support substitutions with sharing
/// as well as dummy variables.
#[derive(Debug, Clone, Copy)]
pub enum UnifyCmd {
/// ```text
/// UTerm t: S, (t e1 ... en) --> S, en, ..., e1
/// USave: H; S, e --> H, e; S, e
/// UTermSave t = USave; UTerm t:
/// H; S, (t e1 ... en) --> H, (t e1 ... en); S, en, ..., e1
/// ```
/// Pop an element from the stack, ensure that the head is `t`, then
/// push the `n` arguments to the term (in reverse order, so that they
/// are dealt with in the correct order in the command stream).
/// `UTermSave` does the same thing but saves the term to the unify heap
/// before the destructuring.
Term {
/// The term that should be at the head
tid: TermId,
/// True if we want to recall this substitution for later
save: bool,
},
/// ```text
/// URef i: H; S, Hi --> H; S
/// ```
/// Get the `i`-th element from the unify heap (the substitution),
/// and match it against the head of the unify stack.
Ref(u32),
/// ```text
/// UDummy s: H; S, x --> H, x; S (where x:s)
/// ```
/// Pop a variable from the unify stack (ensure that it is a name of
/// the appropriate sort) and push it to the heap (ensure that it is
/// distinct from everything else in the substitution).
Dummy(SortId),
/// ```text
/// UHyp (UThm mode): MS, |- e; S --> MS; S, e
/// UHyp (UThmEnd mode): HS, e; S --> HS; S, e
/// ```
/// `UHyp` is a command that is used in theorem declarations to indicate that
/// we are about to read a hypothesis. There are two contexts where we read
/// this, when we are first declaring the theorem and check the statement (`UThmEnd` mode),
/// and later when we are applying the theorem and have to apply a substitution (`UThm` mode).
/// When we are applying the theorem, we have `|- e` on the main stack, and we
/// pop that and load the expression onto the unify stack.
/// When we are checking a theorem, we have been pushing hypotheses onto the
/// hypothesis stack, so we pop it from there instead.
Hyp,
}
impl std::convert::TryFrom<(u8, u32)> for UnifyCmd {
type Error = ParseError;
fn try_from((cmd, data): (u8, u32)) -> Result<Self, Self::Error> {
Ok(match cmd {
cmd::UNIFY_TERM => UnifyCmd::Term { tid: TermId(data), save: false },
cmd::UNIFY_TERM_SAVE => UnifyCmd::Term { tid: TermId(data), save: true },
cmd::UNIFY_REF => UnifyCmd::Ref(data),
cmd::UNIFY_DUMMY =>
UnifyCmd::Dummy(SortId(data.try_into().map_err(|_| ParseError::UnifyCmdConv(cmd, data))?)),
cmd::UNIFY_HYP => UnifyCmd::Hyp,
_ => return Err(ParseError::UnifyCmdConv(cmd, data)),
})
}
}
/// The header of an MMB file, which is always in the first bytes of the file.
/// It is followed by a `sorts: [`[`SortData`]`; num_sorts]` array
/// (which we keep separate because of the dependency).
#[repr(C, align(8))]
#[derive(Debug, Clone, Copy, Default, FromBytes, AsBytes)]
pub struct Header {
/// The magic number, which is used to identify this as an mmb file. Must be
/// equal to [`MM0B_MAGIC`](cmd::MM0B_MAGIC) = `"MM0B"`.
pub magic: [u8; 4],
/// The MMB format version number. Must equal [`MM0B_VERSION`](cmd::MM0B_VERSION) = 1.
pub version: u8,
/// The number of sorts in the file. This is limited to 128.
pub num_sorts: u8,
/// Padding.
pub reserved: [u8; 2],
/// The number of terms and defs in the file.
pub num_terms: U32<LE>,
/// The number of axioms and theorems in the file.
pub num_thms: U32<LE>,
/// The pointer to the term table of type `[`[`TermEntry`]`; num_terms]`.
pub p_terms: U32<LE>,
/// The pointer to the theorem table of type `[`[`ThmEntry`]`; num_thms]`.
pub p_thms: U32<LE>,
/// The pointer to the declaration stream.
pub p_proof: U32<LE>,
/// Padding.
pub reserved2: [u8; 4],
/// The pointer to the index header, an array of `id, data` fields that are parsed by
/// [`MmbIndexBuilder::build`].
pub p_index: U64<LE>,
}
impl Header {
/// On top of the magic number and version checks, perform a non-exhaustive list of
/// miscellaneous checks to see whether there are issues with
/// the header that won't be caught by the type system or the integer parsers.
///
/// For example, none of the pointers in the header should be greater than the length
/// of the file, the terms pointer should be less than the theorems pointer, etc.
pub fn check(&self, mmb: &[u8]) -> Result<(), ParseError> {
use crate::cmd::{MM0B_MAGIC, MM0B_VERSION};
if self.magic != MM0B_MAGIC {
return Err(ParseError::BadMagic { parsed_magic: self.magic })
}
if self.version != MM0B_VERSION {
return Err(ParseError::BadVersion { parsed_version: self.version })
}
let p_terms = u32_as_usize(self.p_terms.get());
let p_thms = u32_as_usize(self.p_thms.get());
let p_proof = u32_as_usize(self.p_proof.get());
let p_index = u64_as_usize(self.p_index);
let headerspace = size_of::<Header>();
let sortspace = self.num_sorts as usize;
let termspace = size_of::<u32>() * u32_as_usize(self.num_terms.get());
let thmspace = size_of::<u32>() * u32_as_usize(self.num_thms.get());
if headerspace + sortspace <= p_terms
&& p_terms + termspace <= p_thms
&& p_thms + thmspace <= p_proof
&& p_proof <= mmb.len()
&& (p_index == 0 || p_proof < p_index && p_index <= mmb.len())
{
Ok(())
} else {
Err(ParseError::SuspectHeader)
}
}
}
/// A sort entry in the file header. Each sort is one byte, which can be any combination
/// of the modifiers in [`Modifiers::sort_data`]: [`PURE`](Modifiers::PURE),
/// [`STRICT`](Modifiers::STRICT), [`PROVABLE`](Modifiers::PROVABLE), [`FREE`](Modifiers::FREE).
#[repr(C)]
#[derive(Debug, Clone, Copy, FromBytes, AsBytes, Unaligned)]
pub struct SortData(pub u8);
impl TryFrom<SortData> for Modifiers {
type Error = ();
#[inline]
fn try_from(s: SortData) -> Result<Modifiers, ()> {
let m = Modifiers::new(s.0);
if Modifiers::sort_data().contains(m) {
Ok(m)
} else {
Err(())
}
}
}
/// An entry in the term table, which describes the "signature" of the term/def,
/// the information needed to apply the term and use it in theorems.
#[repr(C, align(8))]
#[derive(Debug, Clone, Copy, FromBytes, AsBytes)]
pub struct TermEntry {
/// The number of arguments to the term.
pub num_args: U16<LE>,
/// The high bit is set if this is a `def`. The low 7 bits give the
/// return sort of the term.
pub sort: u8,
/// Padding.
pub reserved: u8,
/// The pointer to an `args: [`[`Arg`]`; num_args + 1]` array, followed by the
/// term's unify command sequence. `args[num_args]` is the return type and dependencies,
/// and `args[..num_args]` are the actual arguments.
pub p_args: U32<LE>,
}
/// An entry in the theorem table, which describes the "signature" of the axiom/theorem,
/// the information needed to apply the theorem to use it in other theorems.
#[repr(C, align(8))]
#[derive(Debug, Clone, Copy, FromBytes, AsBytes)]
pub struct ThmEntry {
/// The number of arguments to the theorem (exprs, not hyps).
pub num_args: U16<LE>,
/// Padding.
pub reserved: [u8; 2],
/// The pointer to an `args: [`[`Arg`]`; num_args]` array, followed by the
/// theorem's unify command sequence.
pub p_args: U32<LE>,
}
/// An index table entry, which is essentially an ID describing the table format, and some
/// additional data to find the actual table.
#[repr(C, align(8))]
#[derive(Debug, Clone, Copy, FromBytes, AsBytes)]
pub struct TableEntry {
/// A magic number that identifies this table entry, and determines the interpretation of the
/// rest of the data.
pub id: [u8; 4],
/// A 4 byte data field whose interpretation depends on the entry type.
pub data: U32<LE>,
/// An 8 byte data field whose interpretation depends on the entry type, but is generally a
/// pointer to the actual table data.
pub ptr: U64<LE>,
}
/// An individual symbol name entry in the index.
#[repr(C, align(8))]
#[derive(Debug, Clone, Copy, FromBytes, AsBytes)]
pub struct NameEntry {
/// A pointer to the location in the proof stream which introduced this entity.
pub p_proof: U64<LE>,
/// A pointer to the entity's name as a UTF-8 C string.
pub p_name: U64<LE>,
}