1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! MIR datatypes and passes. See [the README](README.md) for details.
13 use graphviz::IntoCow;
14 use middle::const_val::ConstVal;
15 use middle::region::CodeExtent;
16 use rustc_const_math::{ConstUsize, ConstInt, ConstMathErr};
17 use rustc_data_structures::indexed_vec::{IndexVec, Idx};
18 use rustc_data_structures::control_flow_graph::dominators::{Dominators, dominators};
19 use rustc_data_structures::control_flow_graph::{GraphPredecessors, GraphSuccessors};
20 use rustc_data_structures::control_flow_graph::ControlFlowGraph;
21 use hir::def::CtorKind;
22 use hir::def_id::DefId;
23 use ty::subst::{Subst, Substs};
24 use ty::{self, AdtDef, ClosureSubsts, Region, Ty};
25 use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
27 use rustc_back::slice;
28 use hir::{self, InlineAsm};
30 use std::borrow::{Cow};
32 use std::fmt::{self, Debug, Formatter, Write};
34 use std::ops::{Index, IndexMut};
35 use std::vec::IntoIter;
36 use syntax::ast::Name;
45 macro_rules! newtype_index {
46 ($name:ident, $debug_name:expr) => (
47 #[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord,
48 RustcEncodable, RustcDecodable)]
49 pub struct $name(u32);
52 fn new(value: usize) -> Self {
53 assert!(value < (u32::MAX) as usize);
56 fn index(self) -> usize {
61 impl Debug for $name {
62 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
63 write!(fmt, "{}{}", $debug_name, self.0)
70 type LocalDecls<'tcx> = IndexVec<Local, LocalDecl<'tcx>>;
72 pub trait HasLocalDecls<'tcx> {
73 fn local_decls(&self) -> &LocalDecls<'tcx>;
76 impl<'tcx> HasLocalDecls<'tcx> for LocalDecls<'tcx> {
77 fn local_decls(&self) -> &LocalDecls<'tcx> {
82 impl<'tcx> HasLocalDecls<'tcx> for Mir<'tcx> {
83 fn local_decls(&self) -> &LocalDecls<'tcx> {
88 /// Lowered representation of a single function.
89 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
90 pub struct Mir<'tcx> {
91 /// List of basic blocks. References to basic block use a newtyped index type `BasicBlock`
92 /// that indexes into this vector.
93 basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
95 /// List of visibility (lexical) scopes; these are referenced by statements
96 /// and used (eventually) for debuginfo. Indexed by a `VisibilityScope`.
97 pub visibility_scopes: IndexVec<VisibilityScope, VisibilityScopeData>,
99 /// Rvalues promoted from this function, such as borrows of constants.
100 /// Each of them is the Mir of a constant with the fn's type parameters
101 /// in scope, but a separate set of locals.
102 pub promoted: IndexVec<Promoted, Mir<'tcx>>,
104 /// Return type of the function.
105 pub return_ty: Ty<'tcx>,
107 /// Yield type of the function, if it is a generator.
108 pub yield_ty: Option<Ty<'tcx>>,
110 /// Generator drop glue
111 pub generator_drop: Option<Box<Mir<'tcx>>>,
113 /// The layout of a generator. Produced by the state transformation.
114 pub generator_layout: Option<GeneratorLayout<'tcx>>,
116 /// Declarations of locals.
118 /// The first local is the return value pointer, followed by `arg_count`
119 /// locals for the function arguments, followed by any user-declared
120 /// variables and temporaries.
121 pub local_decls: LocalDecls<'tcx>,
123 /// Number of arguments this function takes.
125 /// Starting at local 1, `arg_count` locals will be provided by the caller
126 /// and can be assumed to be initialized.
128 /// If this MIR was built for a constant, this will be 0.
129 pub arg_count: usize,
131 /// Names and capture modes of all the closure upvars, assuming
132 /// the first argument is either the closure or a reference to it.
133 pub upvar_decls: Vec<UpvarDecl>,
135 /// Mark an argument local (which must be a tuple) as getting passed as
136 /// its individual components at the LLVM level.
138 /// This is used for the "rust-call" ABI.
139 pub spread_arg: Option<Local>,
141 /// A span representing this MIR, for error reporting
144 /// A cache for various calculations
148 /// where execution begins
149 pub const START_BLOCK: BasicBlock = BasicBlock(0);
151 impl<'tcx> Mir<'tcx> {
152 pub fn new(basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>,
153 visibility_scopes: IndexVec<VisibilityScope, VisibilityScopeData>,
154 promoted: IndexVec<Promoted, Mir<'tcx>>,
156 yield_ty: Option<Ty<'tcx>>,
157 local_decls: IndexVec<Local, LocalDecl<'tcx>>,
159 upvar_decls: Vec<UpvarDecl>,
162 // We need `arg_count` locals, and one for the return pointer
163 assert!(local_decls.len() >= arg_count + 1,
164 "expected at least {} locals, got {}", arg_count + 1, local_decls.len());
165 assert_eq!(local_decls[RETURN_POINTER].ty, return_ty);
173 generator_drop: None,
174 generator_layout: None,
180 cache: cache::Cache::new()
185 pub fn basic_blocks(&self) -> &IndexVec<BasicBlock, BasicBlockData<'tcx>> {
190 pub fn basic_blocks_mut(&mut self) -> &mut IndexVec<BasicBlock, BasicBlockData<'tcx>> {
191 self.cache.invalidate();
192 &mut self.basic_blocks
196 pub fn predecessors(&self) -> Ref<IndexVec<BasicBlock, Vec<BasicBlock>>> {
197 self.cache.predecessors(self)
201 pub fn predecessors_for(&self, bb: BasicBlock) -> Ref<Vec<BasicBlock>> {
202 Ref::map(self.predecessors(), |p| &p[bb])
206 pub fn dominators(&self) -> Dominators<BasicBlock> {
211 pub fn local_kind(&self, local: Local) -> LocalKind {
212 let index = local.0 as usize;
214 debug_assert!(self.local_decls[local].mutability == Mutability::Mut,
215 "return pointer should be mutable");
217 LocalKind::ReturnPointer
218 } else if index < self.arg_count + 1 {
220 } else if self.local_decls[local].name.is_some() {
223 debug_assert!(self.local_decls[local].mutability == Mutability::Mut,
224 "temp should be mutable");
230 /// Returns an iterator over all temporaries.
232 pub fn temps_iter<'a>(&'a self) -> impl Iterator<Item=Local> + 'a {
233 (self.arg_count+1..self.local_decls.len()).filter_map(move |index| {
234 let local = Local::new(index);
235 if self.local_decls[local].is_user_variable {
243 /// Returns an iterator over all user-declared locals.
245 pub fn vars_iter<'a>(&'a self) -> impl Iterator<Item=Local> + 'a {
246 (self.arg_count+1..self.local_decls.len()).filter_map(move |index| {
247 let local = Local::new(index);
248 if self.local_decls[local].is_user_variable {
256 /// Returns an iterator over all function arguments.
258 pub fn args_iter(&self) -> impl Iterator<Item=Local> {
259 let arg_count = self.arg_count;
260 (1..arg_count+1).map(Local::new)
263 /// Returns an iterator over all user-defined variables and compiler-generated temporaries (all
264 /// locals that are neither arguments nor the return pointer).
266 pub fn vars_and_temps_iter(&self) -> impl Iterator<Item=Local> {
267 let arg_count = self.arg_count;
268 let local_count = self.local_decls.len();
269 (arg_count+1..local_count).map(Local::new)
272 /// Changes a statement to a nop. This is both faster than deleting instructions and avoids
273 /// invalidating statement indices in `Location`s.
274 pub fn make_statement_nop(&mut self, location: Location) {
275 let block = &mut self[location.block];
276 debug_assert!(location.statement_index < block.statements.len());
277 block.statements[location.statement_index].make_nop()
281 impl_stable_hash_for!(struct Mir<'tcx> {
297 impl<'tcx> Index<BasicBlock> for Mir<'tcx> {
298 type Output = BasicBlockData<'tcx>;
301 fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> {
302 &self.basic_blocks()[index]
306 impl<'tcx> IndexMut<BasicBlock> for Mir<'tcx> {
308 fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> {
309 &mut self.basic_blocks_mut()[index]
313 /// Grouped information about the source code origin of a MIR entity.
314 /// Intended to be inspected by diagnostics and debuginfo.
315 /// Most passes can work with it as a whole, within a single function.
316 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
317 pub struct SourceInfo {
318 /// Source span for the AST pertaining to this MIR entity.
321 /// The lexical visibility scope, i.e. which bindings can be seen.
322 pub scope: VisibilityScope
325 ///////////////////////////////////////////////////////////////////////////
326 // Mutability and borrow kinds
328 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
329 pub enum Mutability {
334 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
335 pub enum BorrowKind {
336 /// Data must be immutable and is aliasable.
339 /// Data must be immutable but not aliasable. This kind of borrow
340 /// cannot currently be expressed by the user and is used only in
341 /// implicit closure bindings. It is needed when you the closure
342 /// is borrowing or mutating a mutable referent, e.g.:
344 /// let x: &mut isize = ...;
345 /// let y = || *x += 5;
347 /// If we were to try to translate this closure into a more explicit
348 /// form, we'd encounter an error with the code as written:
350 /// struct Env { x: & &mut isize }
351 /// let x: &mut isize = ...;
352 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
353 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
355 /// This is then illegal because you cannot mutate a `&mut` found
356 /// in an aliasable location. To solve, you'd have to translate with
357 /// an `&mut` borrow:
359 /// struct Env { x: & &mut isize }
360 /// let x: &mut isize = ...;
361 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
362 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
364 /// Now the assignment to `**env.x` is legal, but creating a
365 /// mutable pointer to `x` is not because `x` is not mutable. We
366 /// could fix this by declaring `x` as `let mut x`. This is ok in
367 /// user code, if awkward, but extra weird for closures, since the
368 /// borrow is hidden.
370 /// So we introduce a "unique imm" borrow -- the referent is
371 /// immutable, but not aliasable. This solves the problem. For
372 /// simplicity, we don't give users the way to express this
373 /// borrow, it's just used when translating closures.
376 /// Data is mutable and not aliasable.
380 ///////////////////////////////////////////////////////////////////////////
381 // Variables and temps
383 newtype_index!(Local, "_");
385 pub const RETURN_POINTER: Local = Local(0);
387 /// Classifies locals into categories. See `Mir::local_kind`.
388 #[derive(PartialEq, Eq, Debug)]
390 /// User-declared variable binding
392 /// Compiler-introduced temporary
394 /// Function argument
396 /// Location of function's return value
402 /// This can be a binding declared by the user, a temporary inserted by the compiler, a function
403 /// argument, or the return pointer.
404 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
405 pub struct LocalDecl<'tcx> {
406 /// `let mut x` vs `let x`.
408 /// Temporaries and the return pointer are always mutable.
409 pub mutability: Mutability,
411 /// True if this corresponds to a user-declared local variable.
412 pub is_user_variable: bool,
414 /// True if this is an internal local.
415 /// Such locals are not checked against the legal types in a generator.
417 /// Scalar state variables created by optimizations (e.g. nonzeroing drop
418 /// flags) should not be included in generator OIBIT computations.
419 /// Therefore, we mark them as `internal` so we can ignore them when
420 /// sanity-checking the OIBIT list.
423 /// Type of this local.
426 /// Name of the local, used in debuginfo and pretty-printing.
428 /// Note that function arguments can also have this set to `Some(_)`
429 /// to generate better debuginfo.
430 pub name: Option<Name>,
432 /// Source info of the local.
433 pub source_info: SourceInfo,
436 impl<'tcx> LocalDecl<'tcx> {
437 /// Create a new `LocalDecl` for a temporary.
439 pub fn new_temp(ty: Ty<'tcx>, span: Span) -> Self {
441 mutability: Mutability::Mut,
444 source_info: SourceInfo {
446 scope: ARGUMENT_VISIBILITY_SCOPE
449 is_user_variable: false
453 /// Create a new `LocalDecl` for a internal temporary.
455 pub fn new_internal(ty: Ty<'tcx>, span: Span) -> Self {
457 mutability: Mutability::Mut,
460 source_info: SourceInfo {
462 scope: ARGUMENT_VISIBILITY_SCOPE
465 is_user_variable: false
469 /// Builds a `LocalDecl` for the return pointer.
471 /// This must be inserted into the `local_decls` list as the first local.
473 pub fn new_return_pointer(return_ty: Ty, span: Span) -> LocalDecl {
475 mutability: Mutability::Mut,
477 source_info: SourceInfo {
479 scope: ARGUMENT_VISIBILITY_SCOPE
482 name: None, // FIXME maybe we do want some name here?
483 is_user_variable: false
488 /// A closure capture, with its name and mode.
489 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
490 pub struct UpvarDecl {
491 pub debug_name: Name,
493 /// If true, the capture is behind a reference.
497 ///////////////////////////////////////////////////////////////////////////
500 newtype_index!(BasicBlock, "bb");
502 ///////////////////////////////////////////////////////////////////////////
503 // BasicBlockData and Terminator
505 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
506 pub struct BasicBlockData<'tcx> {
507 /// List of statements in this block.
508 pub statements: Vec<Statement<'tcx>>,
510 /// Terminator for this block.
512 /// NB. This should generally ONLY be `None` during construction.
513 /// Therefore, you should generally access it via the
514 /// `terminator()` or `terminator_mut()` methods. The only
515 /// exception is that certain passes, such as `simplify_cfg`, swap
516 /// out the terminator temporarily with `None` while they continue
517 /// to recurse over the set of basic blocks.
518 pub terminator: Option<Terminator<'tcx>>,
520 /// If true, this block lies on an unwind path. This is used
521 /// during trans where distinct kinds of basic blocks may be
522 /// generated (particularly for MSVC cleanup). Unwind blocks must
523 /// only branch to other unwind blocks.
524 pub is_cleanup: bool,
527 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
528 pub struct Terminator<'tcx> {
529 pub source_info: SourceInfo,
530 pub kind: TerminatorKind<'tcx>
533 #[derive(Clone, RustcEncodable, RustcDecodable)]
534 pub enum TerminatorKind<'tcx> {
535 /// block should have one successor in the graph; we jump there
540 /// operand evaluates to an integer; jump depending on its value
541 /// to one of the targets, and otherwise fallback to `otherwise`
543 /// discriminant value being tested
544 discr: Operand<'tcx>,
546 /// type of value being tested
549 /// Possible values. The locations to branch to in each case
550 /// are found in the corresponding indices from the `targets` vector.
551 values: Cow<'tcx, [ConstInt]>,
553 /// Possible branch sites. The last element of this vector is used
554 /// for the otherwise branch, so targets.len() == values.len() + 1
556 // This invariant is quite non-obvious and also could be improved.
557 // One way to make this invariant is to have something like this instead:
559 // branches: Vec<(ConstInt, BasicBlock)>,
560 // otherwise: Option<BasicBlock> // exhaustive if None
562 // However we’ve decided to keep this as-is until we figure a case
563 // where some other approach seems to be strictly better than other.
564 targets: Vec<BasicBlock>,
567 /// Indicates that the landing pad is finished and unwinding should
568 /// continue. Emitted by build::scope::diverge_cleanup.
571 /// Indicates a normal return. The return pointer lvalue should
572 /// have been filled in by now. This should occur at most once.
575 /// Indicates a terminator that can never be reached.
580 location: Lvalue<'tcx>,
582 unwind: Option<BasicBlock>
585 /// Drop the Lvalue and assign the new value over it
587 location: Lvalue<'tcx>,
588 value: Operand<'tcx>,
590 unwind: Option<BasicBlock>,
593 /// Block ends with a call of a converging function
595 /// The function that’s being called
597 /// Arguments the function is called with
598 args: Vec<Operand<'tcx>>,
599 /// Destination for the return value. If some, the call is converging.
600 destination: Option<(Lvalue<'tcx>, BasicBlock)>,
601 /// Cleanups to be done if the call unwinds.
602 cleanup: Option<BasicBlock>
605 /// Jump to the target if the condition has the expected value,
606 /// otherwise panic with a message and a cleanup target.
610 msg: AssertMessage<'tcx>,
612 cleanup: Option<BasicBlock>
617 /// The value to return
618 value: Operand<'tcx>,
619 /// Where to resume to
621 /// Cleanup to be done if the generator is dropped at this suspend point
622 drop: Option<BasicBlock>,
625 /// Indicates the end of the dropping of a generator
629 impl<'tcx> Terminator<'tcx> {
630 pub fn successors(&self) -> Cow<[BasicBlock]> {
631 self.kind.successors()
634 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
635 self.kind.successors_mut()
639 impl<'tcx> TerminatorKind<'tcx> {
640 pub fn if_<'a, 'gcx>(tcx: ty::TyCtxt<'a, 'gcx, 'tcx>, cond: Operand<'tcx>,
641 t: BasicBlock, f: BasicBlock) -> TerminatorKind<'tcx> {
642 static BOOL_SWITCH_FALSE: &'static [ConstInt] = &[ConstInt::U8(0)];
643 TerminatorKind::SwitchInt {
645 switch_ty: tcx.types.bool,
646 values: From::from(BOOL_SWITCH_FALSE),
651 pub fn successors(&self) -> Cow<[BasicBlock]> {
652 use self::TerminatorKind::*;
654 Goto { target: ref b } => slice::ref_slice(b).into_cow(),
655 SwitchInt { targets: ref b, .. } => b[..].into_cow(),
656 Resume | GeneratorDrop => (&[]).into_cow(),
657 Return => (&[]).into_cow(),
658 Unreachable => (&[]).into_cow(),
659 Call { destination: Some((_, t)), cleanup: Some(c), .. } => vec![t, c].into_cow(),
660 Call { destination: Some((_, ref t)), cleanup: None, .. } =>
661 slice::ref_slice(t).into_cow(),
662 Call { destination: None, cleanup: Some(ref c), .. } => slice::ref_slice(c).into_cow(),
663 Call { destination: None, cleanup: None, .. } => (&[]).into_cow(),
664 Yield { resume: t, drop: Some(c), .. } => vec![t, c].into_cow(),
665 Yield { resume: ref t, drop: None, .. } => slice::ref_slice(t).into_cow(),
666 DropAndReplace { target, unwind: Some(unwind), .. } |
667 Drop { target, unwind: Some(unwind), .. } => {
668 vec![target, unwind].into_cow()
670 DropAndReplace { ref target, unwind: None, .. } |
671 Drop { ref target, unwind: None, .. } => {
672 slice::ref_slice(target).into_cow()
674 Assert { target, cleanup: Some(unwind), .. } => vec![target, unwind].into_cow(),
675 Assert { ref target, .. } => slice::ref_slice(target).into_cow(),
679 // FIXME: no mootable cow. I’m honestly not sure what a “cow” between `&mut [BasicBlock]` and
680 // `Vec<&mut BasicBlock>` would look like in the first place.
681 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
682 use self::TerminatorKind::*;
684 Goto { target: ref mut b } => vec![b],
685 SwitchInt { targets: ref mut b, .. } => b.iter_mut().collect(),
686 Resume | GeneratorDrop => Vec::new(),
687 Return => Vec::new(),
688 Unreachable => Vec::new(),
689 Call { destination: Some((_, ref mut t)), cleanup: Some(ref mut c), .. } => vec![t, c],
690 Call { destination: Some((_, ref mut t)), cleanup: None, .. } => vec![t],
691 Call { destination: None, cleanup: Some(ref mut c), .. } => vec![c],
692 Call { destination: None, cleanup: None, .. } => vec![],
693 Yield { resume: ref mut t, drop: Some(ref mut c), .. } => vec![t, c],
694 Yield { resume: ref mut t, drop: None, .. } => vec![t],
695 DropAndReplace { ref mut target, unwind: Some(ref mut unwind), .. } |
696 Drop { ref mut target, unwind: Some(ref mut unwind), .. } => vec![target, unwind],
697 DropAndReplace { ref mut target, unwind: None, .. } |
698 Drop { ref mut target, unwind: None, .. } => {
701 Assert { ref mut target, cleanup: Some(ref mut unwind), .. } => vec![target, unwind],
702 Assert { ref mut target, .. } => vec![target]
707 impl<'tcx> BasicBlockData<'tcx> {
708 pub fn new(terminator: Option<Terminator<'tcx>>) -> BasicBlockData<'tcx> {
716 /// Accessor for terminator.
718 /// Terminator may not be None after construction of the basic block is complete. This accessor
719 /// provides a convenience way to reach the terminator.
720 pub fn terminator(&self) -> &Terminator<'tcx> {
721 self.terminator.as_ref().expect("invalid terminator state")
724 pub fn terminator_mut(&mut self) -> &mut Terminator<'tcx> {
725 self.terminator.as_mut().expect("invalid terminator state")
728 pub fn retain_statements<F>(&mut self, mut f: F) where F: FnMut(&mut Statement) -> bool {
729 for s in &mut self.statements {
731 s.kind = StatementKind::Nop;
737 impl<'tcx> Debug for TerminatorKind<'tcx> {
738 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
740 let successors = self.successors();
741 let labels = self.fmt_successor_labels();
742 assert_eq!(successors.len(), labels.len());
744 match successors.len() {
747 1 => write!(fmt, " -> {:?}", successors[0]),
750 write!(fmt, " -> [")?;
751 for (i, target) in successors.iter().enumerate() {
755 write!(fmt, "{}: {:?}", labels[i], target)?;
764 impl<'tcx> TerminatorKind<'tcx> {
765 /// Write the "head" part of the terminator; that is, its name and the data it uses to pick the
766 /// successor basic block, if any. The only information not inlcuded is the list of possible
767 /// successors, which may be rendered differently between the text and the graphviz format.
768 pub fn fmt_head<W: Write>(&self, fmt: &mut W) -> fmt::Result {
769 use self::TerminatorKind::*;
771 Goto { .. } => write!(fmt, "goto"),
772 SwitchInt { discr: ref lv, .. } => write!(fmt, "switchInt({:?})", lv),
773 Return => write!(fmt, "return"),
774 GeneratorDrop => write!(fmt, "generator_drop"),
775 Resume => write!(fmt, "resume"),
776 Yield { ref value, .. } => write!(fmt, "_1 = suspend({:?})", value),
777 Unreachable => write!(fmt, "unreachable"),
778 Drop { ref location, .. } => write!(fmt, "drop({:?})", location),
779 DropAndReplace { ref location, ref value, .. } =>
780 write!(fmt, "replace({:?} <- {:?})", location, value),
781 Call { ref func, ref args, ref destination, .. } => {
782 if let Some((ref destination, _)) = *destination {
783 write!(fmt, "{:?} = ", destination)?;
785 write!(fmt, "{:?}(", func)?;
786 for (index, arg) in args.iter().enumerate() {
790 write!(fmt, "{:?}", arg)?;
794 Assert { ref cond, expected, ref msg, .. } => {
795 write!(fmt, "assert(")?;
799 write!(fmt, "{:?}, ", cond)?;
802 AssertMessage::BoundsCheck { ref len, ref index } => {
803 write!(fmt, "{:?}, {:?}, {:?}",
804 "index out of bounds: the len is {} but the index is {}",
807 AssertMessage::Math(ref err) => {
808 write!(fmt, "{:?}", err.description())?;
810 AssertMessage::GeneratorResumedAfterReturn => {
811 write!(fmt, "{:?}", "generator resumed after completion")?;
813 AssertMessage::GeneratorResumedAfterPanic => {
814 write!(fmt, "{:?}", "generator resumed after panicking")?;
823 /// Return the list of labels for the edges to the successor basic blocks.
824 pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
825 use self::TerminatorKind::*;
827 Return | Resume | Unreachable | GeneratorDrop => vec![],
828 Goto { .. } => vec!["".into()],
829 SwitchInt { ref values, .. } => {
832 let mut buf = String::new();
833 fmt_const_val(&mut buf, &ConstVal::Integral(*const_val)).unwrap();
836 .chain(iter::once(String::from("otherwise").into()))
839 Call { destination: Some(_), cleanup: Some(_), .. } =>
840 vec!["return".into_cow(), "unwind".into_cow()],
841 Call { destination: Some(_), cleanup: None, .. } => vec!["return".into_cow()],
842 Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into_cow()],
843 Call { destination: None, cleanup: None, .. } => vec![],
844 Yield { drop: Some(_), .. } =>
845 vec!["resume".into_cow(), "drop".into_cow()],
846 Yield { drop: None, .. } => vec!["resume".into_cow()],
847 DropAndReplace { unwind: None, .. } |
848 Drop { unwind: None, .. } => vec!["return".into_cow()],
849 DropAndReplace { unwind: Some(_), .. } |
850 Drop { unwind: Some(_), .. } => {
851 vec!["return".into_cow(), "unwind".into_cow()]
853 Assert { cleanup: None, .. } => vec!["".into()],
855 vec!["success".into_cow(), "unwind".into_cow()]
860 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
861 pub enum AssertMessage<'tcx> {
867 GeneratorResumedAfterReturn,
868 GeneratorResumedAfterPanic,
871 ///////////////////////////////////////////////////////////////////////////
874 #[derive(Clone, RustcEncodable, RustcDecodable)]
875 pub struct Statement<'tcx> {
876 pub source_info: SourceInfo,
877 pub kind: StatementKind<'tcx>,
880 impl<'tcx> Statement<'tcx> {
881 /// Changes a statement to a nop. This is both faster than deleting instructions and avoids
882 /// invalidating statement indices in `Location`s.
883 pub fn make_nop(&mut self) {
884 self.kind = StatementKind::Nop
888 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
889 pub enum StatementKind<'tcx> {
890 /// Write the RHS Rvalue to the LHS Lvalue.
891 Assign(Lvalue<'tcx>, Rvalue<'tcx>),
893 /// Write the discriminant for a variant to the enum Lvalue.
894 SetDiscriminant { lvalue: Lvalue<'tcx>, variant_index: usize },
896 /// Start a live range for the storage of the local.
897 StorageLive(Lvalue<'tcx>),
899 /// End the current live range for the storage of the local.
900 StorageDead(Lvalue<'tcx>),
902 /// Execute a piece of inline Assembly.
905 outputs: Vec<Lvalue<'tcx>>,
906 inputs: Vec<Operand<'tcx>>
909 /// Assert the given lvalues to be valid inhabitants of their type. These statements are
910 /// currently only interpreted by miri and only generated when "-Z mir-emit-validate" is passed.
911 /// See <https://internals.rust-lang.org/t/types-as-contracts/5562/73> for more details.
912 Validate(ValidationOp, Vec<ValidationOperand<'tcx, Lvalue<'tcx>>>),
914 /// Mark one terminating point of an extent (i.e. static region).
915 /// (The starting point(s) arise implicitly from borrows.)
916 EndRegion(CodeExtent),
918 /// No-op. Useful for deleting instructions without affecting statement indices.
922 /// The `ValidationOp` describes what happens with each of the operands of a
923 /// `Validate` statement.
924 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, PartialEq, Eq)]
925 pub enum ValidationOp {
926 /// Recursively traverse the lvalue following the type and validate that all type
927 /// invariants are maintained. Furthermore, acquire exclusive/read-only access to the
928 /// memory reachable from the lvalue.
930 /// Recursive traverse the *mutable* part of the type and relinquish all exclusive
933 /// Recursive traverse the *mutable* part of the type and relinquish all exclusive
934 /// access *until* the given region ends. Then, access will be recovered.
938 impl Debug for ValidationOp {
939 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
940 use self::ValidationOp::*;
942 Acquire => write!(fmt, "Acquire"),
943 Release => write!(fmt, "Release"),
944 // (reuse lifetime rendering policy from ppaux.)
945 Suspend(ref ce) => write!(fmt, "Suspend({})", ty::ReScope(*ce)),
950 // This is generic so that it can be reused by miri
951 #[derive(Clone, RustcEncodable, RustcDecodable)]
952 pub struct ValidationOperand<'tcx, T> {
955 pub re: Option<CodeExtent>,
956 pub mutbl: hir::Mutability,
959 impl<'tcx, T: Debug> Debug for ValidationOperand<'tcx, T> {
960 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
961 write!(fmt, "{:?}: {:?}", self.lval, self.ty)?;
962 if let Some(ce) = self.re {
963 // (reuse lifetime rendering policy from ppaux.)
964 write!(fmt, "/{}", ty::ReScope(ce))?;
966 if let hir::MutImmutable = self.mutbl {
967 write!(fmt, " (imm)")?;
973 impl<'tcx> Debug for Statement<'tcx> {
974 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
975 use self::StatementKind::*;
977 Assign(ref lv, ref rv) => write!(fmt, "{:?} = {:?}", lv, rv),
978 // (reuse lifetime rendering policy from ppaux.)
979 EndRegion(ref ce) => write!(fmt, "EndRegion({})", ty::ReScope(*ce)),
980 Validate(ref op, ref lvalues) => write!(fmt, "Validate({:?}, {:?})", op, lvalues),
981 StorageLive(ref lv) => write!(fmt, "StorageLive({:?})", lv),
982 StorageDead(ref lv) => write!(fmt, "StorageDead({:?})", lv),
983 SetDiscriminant{lvalue: ref lv, variant_index: index} => {
984 write!(fmt, "discriminant({:?}) = {:?}", lv, index)
986 InlineAsm { ref asm, ref outputs, ref inputs } => {
987 write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs)
989 Nop => write!(fmt, "nop"),
994 ///////////////////////////////////////////////////////////////////////////
997 /// A path to a value; something that can be evaluated without
998 /// changing or disturbing program state.
999 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1000 pub enum Lvalue<'tcx> {
1004 /// static or static mut variable
1005 Static(Box<Static<'tcx>>),
1007 /// projection out of an lvalue (access a field, deref a pointer, etc)
1008 Projection(Box<LvalueProjection<'tcx>>),
1011 /// The def-id of a static, along with its normalized type (which is
1012 /// stored to avoid requiring normalization when reading MIR).
1013 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1014 pub struct Static<'tcx> {
1019 impl_stable_hash_for!(struct Static<'tcx> {
1024 /// The `Projection` data structure defines things of the form `B.x`
1025 /// or `*B` or `B[index]`. Note that it is parameterized because it is
1026 /// shared between `Constant` and `Lvalue`. See the aliases
1027 /// `LvalueProjection` etc below.
1028 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1029 pub struct Projection<'tcx, B, V, T> {
1031 pub elem: ProjectionElem<'tcx, V, T>,
1034 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1035 pub enum ProjectionElem<'tcx, V, T> {
1040 /// These indices are generated by slice patterns. Easiest to explain
1044 /// [X, _, .._, _, _] => { offset: 0, min_length: 4, from_end: false },
1045 /// [_, X, .._, _, _] => { offset: 1, min_length: 4, from_end: false },
1046 /// [_, _, .._, X, _] => { offset: 2, min_length: 4, from_end: true },
1047 /// [_, _, .._, _, X] => { offset: 1, min_length: 4, from_end: true },
1050 /// index or -index (in Python terms), depending on from_end
1052 /// thing being indexed must be at least this long
1054 /// counting backwards from end?
1058 /// These indices are generated by slice patterns.
1060 /// slice[from:-to] in Python terms.
1066 /// "Downcast" to a variant of an ADT. Currently, we only introduce
1067 /// this for ADTs with more than one variant. It may be better to
1068 /// just introduce it always, or always for enums.
1069 Downcast(&'tcx AdtDef, usize),
1072 /// Alias for projections as they appear in lvalues, where the base is an lvalue
1073 /// and the index is an operand.
1074 pub type LvalueProjection<'tcx> = Projection<'tcx, Lvalue<'tcx>, Operand<'tcx>, Ty<'tcx>>;
1076 /// Alias for projections as they appear in lvalues, where the base is an lvalue
1077 /// and the index is an operand.
1078 pub type LvalueElem<'tcx> = ProjectionElem<'tcx, Operand<'tcx>, Ty<'tcx>>;
1080 newtype_index!(Field, "field");
1082 impl<'tcx> Lvalue<'tcx> {
1083 pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
1084 self.elem(ProjectionElem::Field(f, ty))
1087 pub fn deref(self) -> Lvalue<'tcx> {
1088 self.elem(ProjectionElem::Deref)
1091 pub fn downcast(self, adt_def: &'tcx AdtDef, variant_index: usize) -> Lvalue<'tcx> {
1092 self.elem(ProjectionElem::Downcast(adt_def, variant_index))
1095 pub fn index(self, index: Operand<'tcx>) -> Lvalue<'tcx> {
1096 self.elem(ProjectionElem::Index(index))
1099 pub fn elem(self, elem: LvalueElem<'tcx>) -> Lvalue<'tcx> {
1100 Lvalue::Projection(Box::new(LvalueProjection {
1107 impl<'tcx> Debug for Lvalue<'tcx> {
1108 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1109 use self::Lvalue::*;
1112 Local(id) => write!(fmt, "{:?}", id),
1113 Static(box self::Static { def_id, ty }) =>
1114 write!(fmt, "({}: {:?})", ty::tls::with(|tcx| tcx.item_path_str(def_id)), ty),
1115 Projection(ref data) =>
1117 ProjectionElem::Downcast(ref adt_def, index) =>
1118 write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name),
1119 ProjectionElem::Deref =>
1120 write!(fmt, "(*{:?})", data.base),
1121 ProjectionElem::Field(field, ty) =>
1122 write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty),
1123 ProjectionElem::Index(ref index) =>
1124 write!(fmt, "{:?}[{:?}]", data.base, index),
1125 ProjectionElem::ConstantIndex { offset, min_length, from_end: false } =>
1126 write!(fmt, "{:?}[{:?} of {:?}]", data.base, offset, min_length),
1127 ProjectionElem::ConstantIndex { offset, min_length, from_end: true } =>
1128 write!(fmt, "{:?}[-{:?} of {:?}]", data.base, offset, min_length),
1129 ProjectionElem::Subslice { from, to } if to == 0 =>
1130 write!(fmt, "{:?}[{:?}:]", data.base, from),
1131 ProjectionElem::Subslice { from, to } if from == 0 =>
1132 write!(fmt, "{:?}[:-{:?}]", data.base, to),
1133 ProjectionElem::Subslice { from, to } =>
1134 write!(fmt, "{:?}[{:?}:-{:?}]", data.base,
1142 ///////////////////////////////////////////////////////////////////////////
1145 newtype_index!(VisibilityScope, "scope");
1146 pub const ARGUMENT_VISIBILITY_SCOPE : VisibilityScope = VisibilityScope(0);
1148 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
1149 pub struct VisibilityScopeData {
1151 pub parent_scope: Option<VisibilityScope>,
1154 ///////////////////////////////////////////////////////////////////////////
1157 /// These are values that can appear inside an rvalue (or an index
1158 /// lvalue). They are intentionally limited to prevent rvalues from
1159 /// being nested in one another.
1160 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1161 pub enum Operand<'tcx> {
1162 Consume(Lvalue<'tcx>),
1163 Constant(Box<Constant<'tcx>>),
1166 impl<'tcx> Debug for Operand<'tcx> {
1167 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1168 use self::Operand::*;
1170 Constant(ref a) => write!(fmt, "{:?}", a),
1171 Consume(ref lv) => write!(fmt, "{:?}", lv),
1176 impl<'tcx> Operand<'tcx> {
1177 pub fn function_handle<'a>(
1178 tcx: ty::TyCtxt<'a, 'tcx, 'tcx>,
1180 substs: &'tcx Substs<'tcx>,
1183 Operand::Constant(box Constant {
1185 ty: tcx.type_of(def_id).subst(tcx, substs),
1186 literal: Literal::Value { value: ConstVal::Function(def_id, substs) },
1192 ///////////////////////////////////////////////////////////////////////////
1195 #[derive(Clone, RustcEncodable, RustcDecodable)]
1196 pub enum Rvalue<'tcx> {
1197 /// x (either a move or copy, depending on type of x)
1201 Repeat(Operand<'tcx>, ConstUsize),
1204 Ref(Region<'tcx>, BorrowKind, Lvalue<'tcx>),
1206 /// length of a [X] or [X;n] value
1209 Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
1211 BinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
1212 CheckedBinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
1214 NullaryOp(NullOp, Ty<'tcx>),
1215 UnaryOp(UnOp, Operand<'tcx>),
1217 /// Read the discriminant of an ADT.
1219 /// Undefined (i.e. no effort is made to make it defined, but there’s no reason why it cannot
1220 /// be defined to return, say, a 0) if ADT is not an enum.
1221 Discriminant(Lvalue<'tcx>),
1223 /// Create an aggregate value, like a tuple or struct. This is
1224 /// only needed because we want to distinguish `dest = Foo { x:
1225 /// ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case
1226 /// that `Foo` has a destructor. These rvalues can be optimized
1227 /// away after type-checking and before lowering.
1228 Aggregate(Box<AggregateKind<'tcx>>, Vec<Operand<'tcx>>),
1231 #[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1235 /// Convert unique, zero-sized type for a fn to fn()
1238 /// Convert non capturing closure to fn()
1241 /// Convert safe fn() to unsafe fn()
1244 /// "Unsize" -- convert a thin-or-fat pointer to a fat pointer.
1245 /// trans must figure out the details once full monomorphization
1246 /// is known. For example, this could be used to cast from a
1247 /// `&[i32;N]` to a `&[i32]`, or a `Box<T>` to a `Box<Trait>`
1248 /// (presuming `T: Trait`).
1252 #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1253 pub enum AggregateKind<'tcx> {
1254 /// The type is of the element
1257 /// The second field is variant number (discriminant), it's equal to 0
1258 /// for struct and union expressions. The fourth field is active field
1259 /// number and is present only for union expressions.
1260 Adt(&'tcx AdtDef, usize, &'tcx Substs<'tcx>, Option<usize>),
1261 Closure(DefId, ClosureSubsts<'tcx>),
1262 Generator(DefId, ClosureSubsts<'tcx>),
1265 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1267 /// The `+` operator (addition)
1269 /// The `-` operator (subtraction)
1271 /// The `*` operator (multiplication)
1273 /// The `/` operator (division)
1275 /// The `%` operator (modulus)
1277 /// The `^` operator (bitwise xor)
1279 /// The `&` operator (bitwise and)
1281 /// The `|` operator (bitwise or)
1283 /// The `<<` operator (shift left)
1285 /// The `>>` operator (shift right)
1287 /// The `==` operator (equality)
1289 /// The `<` operator (less than)
1291 /// The `<=` operator (less than or equal to)
1293 /// The `!=` operator (not equal to)
1295 /// The `>=` operator (greater than or equal to)
1297 /// The `>` operator (greater than)
1299 /// The `ptr.offset` operator
1304 pub fn is_checkable(self) -> bool {
1307 Add | Sub | Mul | Shl | Shr => true,
1313 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1315 /// Return the size of a value of that type
1317 /// Create a new uninitialized box for a value of that type
1321 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1323 /// The `!` operator for logical inversion
1325 /// The `-` operator for negation
1329 impl<'tcx> Debug for Rvalue<'tcx> {
1330 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1331 use self::Rvalue::*;
1334 Use(ref lvalue) => write!(fmt, "{:?}", lvalue),
1335 Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b),
1336 Len(ref a) => write!(fmt, "Len({:?})", a),
1337 Cast(ref kind, ref lv, ref ty) => write!(fmt, "{:?} as {:?} ({:?})", lv, ty, kind),
1338 BinaryOp(ref op, ref a, ref b) => write!(fmt, "{:?}({:?}, {:?})", op, a, b),
1339 CheckedBinaryOp(ref op, ref a, ref b) => {
1340 write!(fmt, "Checked{:?}({:?}, {:?})", op, a, b)
1342 UnaryOp(ref op, ref a) => write!(fmt, "{:?}({:?})", op, a),
1343 Discriminant(ref lval) => write!(fmt, "discriminant({:?})", lval),
1344 NullaryOp(ref op, ref t) => write!(fmt, "{:?}({:?})", op, t),
1345 Ref(region, borrow_kind, ref lv) => {
1346 let kind_str = match borrow_kind {
1347 BorrowKind::Shared => "",
1348 BorrowKind::Mut | BorrowKind::Unique => "mut ",
1351 // When printing regions, add trailing space if necessary.
1352 let region = if ppaux::verbose() || ppaux::identify_regions() {
1353 let mut region = format!("{}", region);
1354 if region.len() > 0 { region.push(' '); }
1357 // Do not even print 'static
1360 write!(fmt, "&{}{}{:?}", region, kind_str, lv)
1363 Aggregate(ref kind, ref lvs) => {
1364 fn fmt_tuple(fmt: &mut Formatter, lvs: &[Operand]) -> fmt::Result {
1365 let mut tuple_fmt = fmt.debug_tuple("");
1367 tuple_fmt.field(lv);
1373 AggregateKind::Array(_) => write!(fmt, "{:?}", lvs),
1375 AggregateKind::Tuple => {
1377 0 => write!(fmt, "()"),
1378 1 => write!(fmt, "({:?},)", lvs[0]),
1379 _ => fmt_tuple(fmt, lvs),
1383 AggregateKind::Adt(adt_def, variant, substs, _) => {
1384 let variant_def = &adt_def.variants[variant];
1386 ppaux::parameterized(fmt, substs, variant_def.did, &[])?;
1388 match variant_def.ctor_kind {
1389 CtorKind::Const => Ok(()),
1390 CtorKind::Fn => fmt_tuple(fmt, lvs),
1391 CtorKind::Fictive => {
1392 let mut struct_fmt = fmt.debug_struct("");
1393 for (field, lv) in variant_def.fields.iter().zip(lvs) {
1394 struct_fmt.field(&field.name.as_str(), lv);
1401 AggregateKind::Closure(def_id, _) => ty::tls::with(|tcx| {
1402 if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
1403 let name = if tcx.sess.opts.debugging_opts.span_free_formats {
1404 format!("[closure@{:?}]", node_id)
1406 format!("[closure@{:?}]", tcx.hir.span(node_id))
1408 let mut struct_fmt = fmt.debug_struct(&name);
1410 tcx.with_freevars(node_id, |freevars| {
1411 for (freevar, lv) in freevars.iter().zip(lvs) {
1412 let def_id = freevar.def.def_id();
1413 let var_id = tcx.hir.as_local_node_id(def_id).unwrap();
1414 let var_name = tcx.local_var_name_str(var_id);
1415 struct_fmt.field(&var_name, lv);
1421 write!(fmt, "[closure]")
1425 AggregateKind::Generator(def_id, _) => ty::tls::with(|tcx| {
1426 if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
1427 let name = format!("[generator@{:?}]", tcx.hir.span(node_id));
1428 let mut struct_fmt = fmt.debug_struct(&name);
1430 tcx.with_freevars(node_id, |freevars| {
1431 for (freevar, lv) in freevars.iter().zip(lvs) {
1432 let def_id = freevar.def.def_id();
1433 let var_id = tcx.hir.as_local_node_id(def_id).unwrap();
1434 let var_name = tcx.local_var_name_str(var_id);
1435 struct_fmt.field(&var_name, lv);
1437 struct_fmt.field("$state", &lvs[freevars.len()]);
1438 for i in (freevars.len() + 1)..lvs.len() {
1439 struct_fmt.field(&format!("${}", i - freevars.len() - 1),
1446 write!(fmt, "[generator]")
1455 ///////////////////////////////////////////////////////////////////////////
1458 /// Two constants are equal if they are the same constant. Note that
1459 /// this does not necessarily mean that they are "==" in Rust -- in
1460 /// particular one must be wary of `NaN`!
1462 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1463 pub struct Constant<'tcx> {
1466 pub literal: Literal<'tcx>,
1469 newtype_index!(Promoted, "promoted");
1471 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1472 pub enum Literal<'tcx> {
1475 substs: &'tcx Substs<'tcx>,
1478 value: ConstVal<'tcx>,
1481 // Index into the `promoted` vector of `Mir`.
1486 impl<'tcx> Debug for Constant<'tcx> {
1487 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1488 write!(fmt, "{:?}", self.literal)
1492 impl<'tcx> Debug for Literal<'tcx> {
1493 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1494 use self::Literal::*;
1496 Item { def_id, substs } => {
1497 ppaux::parameterized(fmt, substs, def_id, &[])
1499 Value { ref value } => {
1500 write!(fmt, "const ")?;
1501 fmt_const_val(fmt, value)
1503 Promoted { index } => {
1504 write!(fmt, "{:?}", index)
1510 /// Write a `ConstVal` in a way closer to the original source code than the `Debug` output.
1511 fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ConstVal) -> fmt::Result {
1512 use middle::const_val::ConstVal::*;
1514 Float(f) => write!(fmt, "{:?}", f),
1515 Integral(n) => write!(fmt, "{}", n),
1516 Str(ref s) => write!(fmt, "{:?}", s),
1517 ByteStr(ref bytes) => {
1518 let escaped: String = bytes
1520 .flat_map(|&ch| ascii::escape_default(ch).map(|c| c as char))
1522 write!(fmt, "b\"{}\"", escaped)
1524 Bool(b) => write!(fmt, "{:?}", b),
1525 Char(c) => write!(fmt, "{:?}", c),
1527 Function(def_id, _) => write!(fmt, "{}", item_path_str(def_id)),
1528 Struct(_) | Tuple(_) | Array(_) | Repeat(..) =>
1529 bug!("ConstVal `{:?}` should not be in MIR", const_val),
1533 fn item_path_str(def_id: DefId) -> String {
1534 ty::tls::with(|tcx| tcx.item_path_str(def_id))
1537 impl<'tcx> ControlFlowGraph for Mir<'tcx> {
1539 type Node = BasicBlock;
1541 fn num_nodes(&self) -> usize { self.basic_blocks.len() }
1543 fn start_node(&self) -> Self::Node { START_BLOCK }
1545 fn predecessors<'graph>(&'graph self, node: Self::Node)
1546 -> <Self as GraphPredecessors<'graph>>::Iter
1548 self.predecessors_for(node).clone().into_iter()
1550 fn successors<'graph>(&'graph self, node: Self::Node)
1551 -> <Self as GraphSuccessors<'graph>>::Iter
1553 self.basic_blocks[node].terminator().successors().into_owned().into_iter()
1557 impl<'a, 'b> GraphPredecessors<'b> for Mir<'a> {
1558 type Item = BasicBlock;
1559 type Iter = IntoIter<BasicBlock>;
1562 impl<'a, 'b> GraphSuccessors<'b> for Mir<'a> {
1563 type Item = BasicBlock;
1564 type Iter = IntoIter<BasicBlock>;
1567 #[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
1568 pub struct Location {
1569 /// the location is within this block
1570 pub block: BasicBlock,
1572 /// the location is the start of the this statement; or, if `statement_index`
1573 /// == num-statements, then the start of the terminator.
1574 pub statement_index: usize,
1577 impl fmt::Debug for Location {
1578 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
1579 write!(fmt, "{:?}[{}]", self.block, self.statement_index)
1584 pub fn dominates(&self, other: &Location, dominators: &Dominators<BasicBlock>) -> bool {
1585 if self.block == other.block {
1586 self.statement_index <= other.statement_index
1588 dominators.is_dominated_by(other.block, self.block)
1593 /// The layout of generator state
1594 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
1595 pub struct GeneratorLayout<'tcx> {
1596 pub fields: Vec<LocalDecl<'tcx>>,
1600 * TypeFoldable implementations for MIR types
1603 impl<'tcx> TypeFoldable<'tcx> for Mir<'tcx> {
1604 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1606 basic_blocks: self.basic_blocks.fold_with(folder),
1607 visibility_scopes: self.visibility_scopes.clone(),
1608 promoted: self.promoted.fold_with(folder),
1609 return_ty: self.return_ty.fold_with(folder),
1610 yield_ty: self.yield_ty.fold_with(folder),
1611 generator_drop: self.generator_drop.fold_with(folder),
1612 generator_layout: self.generator_layout.fold_with(folder),
1613 local_decls: self.local_decls.fold_with(folder),
1614 arg_count: self.arg_count,
1615 upvar_decls: self.upvar_decls.clone(),
1616 spread_arg: self.spread_arg,
1618 cache: cache::Cache::new()
1622 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1623 self.basic_blocks.visit_with(visitor) ||
1624 self.generator_drop.visit_with(visitor) ||
1625 self.generator_layout.visit_with(visitor) ||
1626 self.yield_ty.visit_with(visitor) ||
1627 self.promoted.visit_with(visitor) ||
1628 self.return_ty.visit_with(visitor) ||
1629 self.local_decls.visit_with(visitor)
1633 impl<'tcx> TypeFoldable<'tcx> for GeneratorLayout<'tcx> {
1634 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1636 fields: self.fields.fold_with(folder),
1640 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1641 self.fields.visit_with(visitor)
1645 impl<'tcx> TypeFoldable<'tcx> for LocalDecl<'tcx> {
1646 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1648 ty: self.ty.fold_with(folder),
1653 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1654 self.ty.visit_with(visitor)
1658 impl<'tcx> TypeFoldable<'tcx> for BasicBlockData<'tcx> {
1659 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1661 statements: self.statements.fold_with(folder),
1662 terminator: self.terminator.fold_with(folder),
1663 is_cleanup: self.is_cleanup
1667 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1668 self.statements.visit_with(visitor) || self.terminator.visit_with(visitor)
1672 impl<'tcx> TypeFoldable<'tcx> for ValidationOperand<'tcx, Lvalue<'tcx>> {
1673 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1675 lval: self.lval.fold_with(folder),
1676 ty: self.ty.fold_with(folder),
1682 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1683 self.lval.visit_with(visitor) || self.ty.visit_with(visitor)
1687 impl<'tcx> TypeFoldable<'tcx> for Statement<'tcx> {
1688 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1689 use mir::StatementKind::*;
1691 let kind = match self.kind {
1692 Assign(ref lval, ref rval) => Assign(lval.fold_with(folder), rval.fold_with(folder)),
1693 SetDiscriminant { ref lvalue, variant_index } => SetDiscriminant {
1694 lvalue: lvalue.fold_with(folder),
1697 StorageLive(ref lval) => StorageLive(lval.fold_with(folder)),
1698 StorageDead(ref lval) => StorageDead(lval.fold_with(folder)),
1699 InlineAsm { ref asm, ref outputs, ref inputs } => InlineAsm {
1701 outputs: outputs.fold_with(folder),
1702 inputs: inputs.fold_with(folder)
1705 // Note for future: If we want to expose the extents
1706 // during the fold, we need to either generalize EndRegion
1707 // to carry `[ty::Region]`, or extend the `TypeFolder`
1708 // trait with a `fn fold_extent`.
1709 EndRegion(ref extent) => EndRegion(extent.clone()),
1711 Validate(ref op, ref lvals) =>
1712 Validate(op.clone(),
1713 lvals.iter().map(|operand| operand.fold_with(folder)).collect()),
1718 source_info: self.source_info,
1723 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1724 use mir::StatementKind::*;
1727 Assign(ref lval, ref rval) => { lval.visit_with(visitor) || rval.visit_with(visitor) }
1728 SetDiscriminant { ref lvalue, .. } |
1729 StorageLive(ref lvalue) |
1730 StorageDead(ref lvalue) => lvalue.visit_with(visitor),
1731 InlineAsm { ref outputs, ref inputs, .. } =>
1732 outputs.visit_with(visitor) || inputs.visit_with(visitor),
1734 // Note for future: If we want to expose the extents
1735 // during the visit, we need to either generalize EndRegion
1736 // to carry `[ty::Region]`, or extend the `TypeVisitor`
1737 // trait with a `fn visit_extent`.
1738 EndRegion(ref _extent) => false,
1740 Validate(ref _op, ref lvalues) =>
1741 lvalues.iter().any(|ty_and_lvalue| ty_and_lvalue.visit_with(visitor)),
1748 impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> {
1749 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1750 use mir::TerminatorKind::*;
1752 let kind = match self.kind {
1753 Goto { target } => Goto { target: target },
1754 SwitchInt { ref discr, switch_ty, ref values, ref targets } => SwitchInt {
1755 discr: discr.fold_with(folder),
1756 switch_ty: switch_ty.fold_with(folder),
1757 values: values.clone(),
1758 targets: targets.clone()
1760 Drop { ref location, target, unwind } => Drop {
1761 location: location.fold_with(folder),
1765 DropAndReplace { ref location, ref value, target, unwind } => DropAndReplace {
1766 location: location.fold_with(folder),
1767 value: value.fold_with(folder),
1771 Yield { ref value, resume, drop } => Yield {
1772 value: value.fold_with(folder),
1776 Call { ref func, ref args, ref destination, cleanup } => {
1777 let dest = destination.as_ref().map(|&(ref loc, dest)| {
1778 (loc.fold_with(folder), dest)
1782 func: func.fold_with(folder),
1783 args: args.fold_with(folder),
1788 Assert { ref cond, expected, ref msg, target, cleanup } => {
1789 let msg = if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
1790 AssertMessage::BoundsCheck {
1791 len: len.fold_with(folder),
1792 index: index.fold_with(folder),
1798 cond: cond.fold_with(folder),
1805 GeneratorDrop => GeneratorDrop,
1808 Unreachable => Unreachable,
1811 source_info: self.source_info,
1816 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1817 use mir::TerminatorKind::*;
1820 SwitchInt { ref discr, switch_ty, .. } =>
1821 discr.visit_with(visitor) || switch_ty.visit_with(visitor),
1822 Drop { ref location, ..} => location.visit_with(visitor),
1823 DropAndReplace { ref location, ref value, ..} =>
1824 location.visit_with(visitor) || value.visit_with(visitor),
1825 Yield { ref value, ..} =>
1826 value.visit_with(visitor),
1827 Call { ref func, ref args, ref destination, .. } => {
1828 let dest = if let Some((ref loc, _)) = *destination {
1829 loc.visit_with(visitor)
1831 dest || func.visit_with(visitor) || args.visit_with(visitor)
1833 Assert { ref cond, ref msg, .. } => {
1834 if cond.visit_with(visitor) {
1835 if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
1836 len.visit_with(visitor) || index.visit_with(visitor)
1848 Unreachable => false
1853 impl<'tcx> TypeFoldable<'tcx> for Lvalue<'tcx> {
1854 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1856 &Lvalue::Projection(ref p) => Lvalue::Projection(p.fold_with(folder)),
1861 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1862 if let &Lvalue::Projection(ref p) = self {
1863 p.visit_with(visitor)
1870 impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> {
1871 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1874 Use(ref op) => Use(op.fold_with(folder)),
1875 Repeat(ref op, len) => Repeat(op.fold_with(folder), len),
1876 Ref(region, bk, ref lval) => Ref(region.fold_with(folder), bk, lval.fold_with(folder)),
1877 Len(ref lval) => Len(lval.fold_with(folder)),
1878 Cast(kind, ref op, ty) => Cast(kind, op.fold_with(folder), ty.fold_with(folder)),
1879 BinaryOp(op, ref rhs, ref lhs) =>
1880 BinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
1881 CheckedBinaryOp(op, ref rhs, ref lhs) =>
1882 CheckedBinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
1883 UnaryOp(op, ref val) => UnaryOp(op, val.fold_with(folder)),
1884 Discriminant(ref lval) => Discriminant(lval.fold_with(folder)),
1885 NullaryOp(op, ty) => NullaryOp(op, ty.fold_with(folder)),
1886 Aggregate(ref kind, ref fields) => {
1887 let kind = box match **kind {
1888 AggregateKind::Array(ty) => AggregateKind::Array(ty.fold_with(folder)),
1889 AggregateKind::Tuple => AggregateKind::Tuple,
1890 AggregateKind::Adt(def, v, substs, n) =>
1891 AggregateKind::Adt(def, v, substs.fold_with(folder), n),
1892 AggregateKind::Closure(id, substs) =>
1893 AggregateKind::Closure(id, substs.fold_with(folder)),
1894 AggregateKind::Generator(id, substs) =>
1895 AggregateKind::Generator(id, substs.fold_with(folder)),
1897 Aggregate(kind, fields.fold_with(folder))
1902 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1905 Use(ref op) => op.visit_with(visitor),
1906 Repeat(ref op, _) => op.visit_with(visitor),
1907 Ref(region, _, ref lval) => region.visit_with(visitor) || lval.visit_with(visitor),
1908 Len(ref lval) => lval.visit_with(visitor),
1909 Cast(_, ref op, ty) => op.visit_with(visitor) || ty.visit_with(visitor),
1910 BinaryOp(_, ref rhs, ref lhs) |
1911 CheckedBinaryOp(_, ref rhs, ref lhs) =>
1912 rhs.visit_with(visitor) || lhs.visit_with(visitor),
1913 UnaryOp(_, ref val) => val.visit_with(visitor),
1914 Discriminant(ref lval) => lval.visit_with(visitor),
1915 NullaryOp(_, ty) => ty.visit_with(visitor),
1916 Aggregate(ref kind, ref fields) => {
1918 AggregateKind::Array(ty) => ty.visit_with(visitor),
1919 AggregateKind::Tuple => false,
1920 AggregateKind::Adt(_, _, substs, _) => substs.visit_with(visitor),
1921 AggregateKind::Closure(_, substs) => substs.visit_with(visitor),
1922 AggregateKind::Generator(_, substs) => substs.visit_with(visitor),
1923 }) || fields.visit_with(visitor)
1929 impl<'tcx> TypeFoldable<'tcx> for Operand<'tcx> {
1930 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1932 Operand::Consume(ref lval) => Operand::Consume(lval.fold_with(folder)),
1933 Operand::Constant(ref c) => Operand::Constant(c.fold_with(folder)),
1937 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1939 Operand::Consume(ref lval) => lval.visit_with(visitor),
1940 Operand::Constant(ref c) => c.visit_with(visitor)
1945 impl<'tcx, B, V, T> TypeFoldable<'tcx> for Projection<'tcx, B, V, T>
1946 where B: TypeFoldable<'tcx>, V: TypeFoldable<'tcx>, T: TypeFoldable<'tcx>
1948 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1949 use mir::ProjectionElem::*;
1951 let base = self.base.fold_with(folder);
1952 let elem = match self.elem {
1954 Field(f, ref ty) => Field(f, ty.fold_with(folder)),
1955 Index(ref v) => Index(v.fold_with(folder)),
1956 ref elem => elem.clone()
1965 fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool {
1966 use mir::ProjectionElem::*;
1968 self.base.visit_with(visitor) ||
1970 Field(_, ref ty) => ty.visit_with(visitor),
1971 Index(ref v) => v.visit_with(visitor),
1977 impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> {
1978 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1980 span: self.span.clone(),
1981 ty: self.ty.fold_with(folder),
1982 literal: self.literal.fold_with(folder)
1985 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1986 self.ty.visit_with(visitor) || self.literal.visit_with(visitor)
1990 impl<'tcx> TypeFoldable<'tcx> for Literal<'tcx> {
1991 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1993 Literal::Item { def_id, substs } => Literal::Item {
1995 substs: substs.fold_with(folder)
2000 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
2002 Literal::Item { substs, .. } => substs.visit_with(visitor),