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;
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, TyCtxt, GeneratorInterior};
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
416 /// These locals are not based on types in the source code and are only used
417 /// for drop flags at the moment.
419 /// The generator transformation will sanity check the locals which are live
420 /// across a suspension point against the type components of the generator
421 /// which type checking knows are live across a suspension point. We need to
422 /// flag drop flags to avoid triggering this check as they are introduced
425 /// This should be sound because the drop flags are fully algebraic, and
426 /// therefore don't affect the OIBIT or outlives properties of the
430 /// Type of this local.
433 /// Name of the local, used in debuginfo and pretty-printing.
435 /// Note that function arguments can also have this set to `Some(_)`
436 /// to generate better debuginfo.
437 pub name: Option<Name>,
439 /// Source info of the local.
440 pub source_info: SourceInfo,
443 impl<'tcx> LocalDecl<'tcx> {
444 /// Create a new `LocalDecl` for a temporary.
446 pub fn new_temp(ty: Ty<'tcx>, span: Span) -> Self {
448 mutability: Mutability::Mut,
451 source_info: SourceInfo {
453 scope: ARGUMENT_VISIBILITY_SCOPE
456 is_user_variable: false
460 /// Create a new `LocalDecl` for a internal temporary.
462 pub fn new_internal(ty: Ty<'tcx>, span: Span) -> Self {
464 mutability: Mutability::Mut,
467 source_info: SourceInfo {
469 scope: ARGUMENT_VISIBILITY_SCOPE
472 is_user_variable: false
476 /// Builds a `LocalDecl` for the return pointer.
478 /// This must be inserted into the `local_decls` list as the first local.
480 pub fn new_return_pointer(return_ty: Ty, span: Span) -> LocalDecl {
482 mutability: Mutability::Mut,
484 source_info: SourceInfo {
486 scope: ARGUMENT_VISIBILITY_SCOPE
489 name: None, // FIXME maybe we do want some name here?
490 is_user_variable: false
495 /// A closure capture, with its name and mode.
496 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
497 pub struct UpvarDecl {
498 pub debug_name: Name,
500 /// If true, the capture is behind a reference.
504 ///////////////////////////////////////////////////////////////////////////
507 newtype_index!(BasicBlock, "bb");
509 ///////////////////////////////////////////////////////////////////////////
510 // BasicBlockData and Terminator
512 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
513 pub struct BasicBlockData<'tcx> {
514 /// List of statements in this block.
515 pub statements: Vec<Statement<'tcx>>,
517 /// Terminator for this block.
519 /// NB. This should generally ONLY be `None` during construction.
520 /// Therefore, you should generally access it via the
521 /// `terminator()` or `terminator_mut()` methods. The only
522 /// exception is that certain passes, such as `simplify_cfg`, swap
523 /// out the terminator temporarily with `None` while they continue
524 /// to recurse over the set of basic blocks.
525 pub terminator: Option<Terminator<'tcx>>,
527 /// If true, this block lies on an unwind path. This is used
528 /// during trans where distinct kinds of basic blocks may be
529 /// generated (particularly for MSVC cleanup). Unwind blocks must
530 /// only branch to other unwind blocks.
531 pub is_cleanup: bool,
534 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
535 pub struct Terminator<'tcx> {
536 pub source_info: SourceInfo,
537 pub kind: TerminatorKind<'tcx>
540 #[derive(Clone, RustcEncodable, RustcDecodable)]
541 pub enum TerminatorKind<'tcx> {
542 /// block should have one successor in the graph; we jump there
547 /// operand evaluates to an integer; jump depending on its value
548 /// to one of the targets, and otherwise fallback to `otherwise`
550 /// discriminant value being tested
551 discr: Operand<'tcx>,
553 /// type of value being tested
556 /// Possible values. The locations to branch to in each case
557 /// are found in the corresponding indices from the `targets` vector.
558 values: Cow<'tcx, [ConstInt]>,
560 /// Possible branch sites. The last element of this vector is used
561 /// for the otherwise branch, so targets.len() == values.len() + 1
563 // This invariant is quite non-obvious and also could be improved.
564 // One way to make this invariant is to have something like this instead:
566 // branches: Vec<(ConstInt, BasicBlock)>,
567 // otherwise: Option<BasicBlock> // exhaustive if None
569 // However we’ve decided to keep this as-is until we figure a case
570 // where some other approach seems to be strictly better than other.
571 targets: Vec<BasicBlock>,
574 /// Indicates that the landing pad is finished and unwinding should
575 /// continue. Emitted by build::scope::diverge_cleanup.
578 /// Indicates a normal return. The return pointer lvalue should
579 /// have been filled in by now. This should occur at most once.
582 /// Indicates a terminator that can never be reached.
587 location: Lvalue<'tcx>,
589 unwind: Option<BasicBlock>
592 /// Drop the Lvalue and assign the new value over it
594 location: Lvalue<'tcx>,
595 value: Operand<'tcx>,
597 unwind: Option<BasicBlock>,
600 /// Block ends with a call of a converging function
602 /// The function that’s being called
604 /// Arguments the function is called with
605 args: Vec<Operand<'tcx>>,
606 /// Destination for the return value. If some, the call is converging.
607 destination: Option<(Lvalue<'tcx>, BasicBlock)>,
608 /// Cleanups to be done if the call unwinds.
609 cleanup: Option<BasicBlock>
612 /// Jump to the target if the condition has the expected value,
613 /// otherwise panic with a message and a cleanup target.
617 msg: AssertMessage<'tcx>,
619 cleanup: Option<BasicBlock>
624 /// The value to return
625 value: Operand<'tcx>,
626 /// Where to resume to
628 /// Cleanup to be done if the generator is dropped at this suspend point
629 drop: Option<BasicBlock>,
632 /// Indicates the end of the dropping of a generator
636 impl<'tcx> Terminator<'tcx> {
637 pub fn successors(&self) -> Cow<[BasicBlock]> {
638 self.kind.successors()
641 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
642 self.kind.successors_mut()
646 impl<'tcx> TerminatorKind<'tcx> {
647 pub fn if_<'a, 'gcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>, cond: Operand<'tcx>,
648 t: BasicBlock, f: BasicBlock) -> TerminatorKind<'tcx> {
649 static BOOL_SWITCH_FALSE: &'static [ConstInt] = &[ConstInt::U8(0)];
650 TerminatorKind::SwitchInt {
652 switch_ty: tcx.types.bool,
653 values: From::from(BOOL_SWITCH_FALSE),
658 pub fn successors(&self) -> Cow<[BasicBlock]> {
659 use self::TerminatorKind::*;
661 Goto { target: ref b } => slice::ref_slice(b).into_cow(),
662 SwitchInt { targets: ref b, .. } => b[..].into_cow(),
663 Resume | GeneratorDrop => (&[]).into_cow(),
664 Return => (&[]).into_cow(),
665 Unreachable => (&[]).into_cow(),
666 Call { destination: Some((_, t)), cleanup: Some(c), .. } => vec![t, c].into_cow(),
667 Call { destination: Some((_, ref t)), cleanup: None, .. } =>
668 slice::ref_slice(t).into_cow(),
669 Call { destination: None, cleanup: Some(ref c), .. } => slice::ref_slice(c).into_cow(),
670 Call { destination: None, cleanup: None, .. } => (&[]).into_cow(),
671 Yield { resume: t, drop: Some(c), .. } => vec![t, c].into_cow(),
672 Yield { resume: ref t, drop: None, .. } => slice::ref_slice(t).into_cow(),
673 DropAndReplace { target, unwind: Some(unwind), .. } |
674 Drop { target, unwind: Some(unwind), .. } => {
675 vec![target, unwind].into_cow()
677 DropAndReplace { ref target, unwind: None, .. } |
678 Drop { ref target, unwind: None, .. } => {
679 slice::ref_slice(target).into_cow()
681 Assert { target, cleanup: Some(unwind), .. } => vec![target, unwind].into_cow(),
682 Assert { ref target, .. } => slice::ref_slice(target).into_cow(),
686 // FIXME: no mootable cow. I’m honestly not sure what a “cow” between `&mut [BasicBlock]` and
687 // `Vec<&mut BasicBlock>` would look like in the first place.
688 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
689 use self::TerminatorKind::*;
691 Goto { target: ref mut b } => vec![b],
692 SwitchInt { targets: ref mut b, .. } => b.iter_mut().collect(),
693 Resume | GeneratorDrop => Vec::new(),
694 Return => Vec::new(),
695 Unreachable => Vec::new(),
696 Call { destination: Some((_, ref mut t)), cleanup: Some(ref mut c), .. } => vec![t, c],
697 Call { destination: Some((_, ref mut t)), cleanup: None, .. } => vec![t],
698 Call { destination: None, cleanup: Some(ref mut c), .. } => vec![c],
699 Call { destination: None, cleanup: None, .. } => vec![],
700 Yield { resume: ref mut t, drop: Some(ref mut c), .. } => vec![t, c],
701 Yield { resume: ref mut t, drop: None, .. } => vec![t],
702 DropAndReplace { ref mut target, unwind: Some(ref mut unwind), .. } |
703 Drop { ref mut target, unwind: Some(ref mut unwind), .. } => vec![target, unwind],
704 DropAndReplace { ref mut target, unwind: None, .. } |
705 Drop { ref mut target, unwind: None, .. } => {
708 Assert { ref mut target, cleanup: Some(ref mut unwind), .. } => vec![target, unwind],
709 Assert { ref mut target, .. } => vec![target]
714 impl<'tcx> BasicBlockData<'tcx> {
715 pub fn new(terminator: Option<Terminator<'tcx>>) -> BasicBlockData<'tcx> {
723 /// Accessor for terminator.
725 /// Terminator may not be None after construction of the basic block is complete. This accessor
726 /// provides a convenience way to reach the terminator.
727 pub fn terminator(&self) -> &Terminator<'tcx> {
728 self.terminator.as_ref().expect("invalid terminator state")
731 pub fn terminator_mut(&mut self) -> &mut Terminator<'tcx> {
732 self.terminator.as_mut().expect("invalid terminator state")
735 pub fn retain_statements<F>(&mut self, mut f: F) where F: FnMut(&mut Statement) -> bool {
736 for s in &mut self.statements {
738 s.kind = StatementKind::Nop;
744 impl<'tcx> Debug for TerminatorKind<'tcx> {
745 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
747 let successors = self.successors();
748 let labels = self.fmt_successor_labels();
749 assert_eq!(successors.len(), labels.len());
751 match successors.len() {
754 1 => write!(fmt, " -> {:?}", successors[0]),
757 write!(fmt, " -> [")?;
758 for (i, target) in successors.iter().enumerate() {
762 write!(fmt, "{}: {:?}", labels[i], target)?;
771 impl<'tcx> TerminatorKind<'tcx> {
772 /// Write the "head" part of the terminator; that is, its name and the data it uses to pick the
773 /// successor basic block, if any. The only information not included is the list of possible
774 /// successors, which may be rendered differently between the text and the graphviz format.
775 pub fn fmt_head<W: Write>(&self, fmt: &mut W) -> fmt::Result {
776 use self::TerminatorKind::*;
778 Goto { .. } => write!(fmt, "goto"),
779 SwitchInt { discr: ref lv, .. } => write!(fmt, "switchInt({:?})", lv),
780 Return => write!(fmt, "return"),
781 GeneratorDrop => write!(fmt, "generator_drop"),
782 Resume => write!(fmt, "resume"),
783 Yield { ref value, .. } => write!(fmt, "_1 = suspend({:?})", value),
784 Unreachable => write!(fmt, "unreachable"),
785 Drop { ref location, .. } => write!(fmt, "drop({:?})", location),
786 DropAndReplace { ref location, ref value, .. } =>
787 write!(fmt, "replace({:?} <- {:?})", location, value),
788 Call { ref func, ref args, ref destination, .. } => {
789 if let Some((ref destination, _)) = *destination {
790 write!(fmt, "{:?} = ", destination)?;
792 write!(fmt, "{:?}(", func)?;
793 for (index, arg) in args.iter().enumerate() {
797 write!(fmt, "{:?}", arg)?;
801 Assert { ref cond, expected, ref msg, .. } => {
802 write!(fmt, "assert(")?;
806 write!(fmt, "{:?}, ", cond)?;
809 AssertMessage::BoundsCheck { ref len, ref index } => {
810 write!(fmt, "{:?}, {:?}, {:?}",
811 "index out of bounds: the len is {} but the index is {}",
814 AssertMessage::Math(ref err) => {
815 write!(fmt, "{:?}", err.description())?;
817 AssertMessage::GeneratorResumedAfterReturn => {
818 write!(fmt, "{:?}", "generator resumed after completion")?;
820 AssertMessage::GeneratorResumedAfterPanic => {
821 write!(fmt, "{:?}", "generator resumed after panicking")?;
830 /// Return the list of labels for the edges to the successor basic blocks.
831 pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
832 use self::TerminatorKind::*;
834 Return | Resume | Unreachable | GeneratorDrop => vec![],
835 Goto { .. } => vec!["".into()],
836 SwitchInt { ref values, .. } => {
839 let mut buf = String::new();
840 fmt_const_val(&mut buf, &ConstVal::Integral(*const_val)).unwrap();
843 .chain(iter::once(String::from("otherwise").into()))
846 Call { destination: Some(_), cleanup: Some(_), .. } =>
847 vec!["return".into_cow(), "unwind".into_cow()],
848 Call { destination: Some(_), cleanup: None, .. } => vec!["return".into_cow()],
849 Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into_cow()],
850 Call { destination: None, cleanup: None, .. } => vec![],
851 Yield { drop: Some(_), .. } =>
852 vec!["resume".into_cow(), "drop".into_cow()],
853 Yield { drop: None, .. } => vec!["resume".into_cow()],
854 DropAndReplace { unwind: None, .. } |
855 Drop { unwind: None, .. } => vec!["return".into_cow()],
856 DropAndReplace { unwind: Some(_), .. } |
857 Drop { unwind: Some(_), .. } => {
858 vec!["return".into_cow(), "unwind".into_cow()]
860 Assert { cleanup: None, .. } => vec!["".into()],
862 vec!["success".into_cow(), "unwind".into_cow()]
867 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
868 pub enum AssertMessage<'tcx> {
874 GeneratorResumedAfterReturn,
875 GeneratorResumedAfterPanic,
878 ///////////////////////////////////////////////////////////////////////////
881 #[derive(Clone, RustcEncodable, RustcDecodable)]
882 pub struct Statement<'tcx> {
883 pub source_info: SourceInfo,
884 pub kind: StatementKind<'tcx>,
887 impl<'tcx> Statement<'tcx> {
888 /// Changes a statement to a nop. This is both faster than deleting instructions and avoids
889 /// invalidating statement indices in `Location`s.
890 pub fn make_nop(&mut self) {
891 self.kind = StatementKind::Nop
895 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
896 pub enum StatementKind<'tcx> {
897 /// Write the RHS Rvalue to the LHS Lvalue.
898 Assign(Lvalue<'tcx>, Rvalue<'tcx>),
900 /// Write the discriminant for a variant to the enum Lvalue.
901 SetDiscriminant { lvalue: Lvalue<'tcx>, variant_index: usize },
903 /// Start a live range for the storage of the local.
906 /// End the current live range for the storage of the local.
909 /// Execute a piece of inline Assembly.
912 outputs: Vec<Lvalue<'tcx>>,
913 inputs: Vec<Operand<'tcx>>
916 /// Assert the given lvalues to be valid inhabitants of their type. These statements are
917 /// currently only interpreted by miri and only generated when "-Z mir-emit-validate" is passed.
918 /// See <https://internals.rust-lang.org/t/types-as-contracts/5562/73> for more details.
919 Validate(ValidationOp, Vec<ValidationOperand<'tcx, Lvalue<'tcx>>>),
921 /// Mark one terminating point of a region scope (i.e. static region).
922 /// (The starting point(s) arise implicitly from borrows.)
923 EndRegion(region::Scope),
925 /// No-op. Useful for deleting instructions without affecting statement indices.
929 /// The `ValidationOp` describes what happens with each of the operands of a
930 /// `Validate` statement.
931 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, PartialEq, Eq)]
932 pub enum ValidationOp {
933 /// Recursively traverse the lvalue following the type and validate that all type
934 /// invariants are maintained. Furthermore, acquire exclusive/read-only access to the
935 /// memory reachable from the lvalue.
937 /// Recursive traverse the *mutable* part of the type and relinquish all exclusive
940 /// Recursive traverse the *mutable* part of the type and relinquish all exclusive
941 /// access *until* the given region ends. Then, access will be recovered.
942 Suspend(region::Scope),
945 impl Debug for ValidationOp {
946 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
947 use self::ValidationOp::*;
949 Acquire => write!(fmt, "Acquire"),
950 Release => write!(fmt, "Release"),
951 // (reuse lifetime rendering policy from ppaux.)
952 Suspend(ref ce) => write!(fmt, "Suspend({})", ty::ReScope(*ce)),
957 // This is generic so that it can be reused by miri
958 #[derive(Clone, RustcEncodable, RustcDecodable)]
959 pub struct ValidationOperand<'tcx, T> {
962 pub re: Option<region::Scope>,
963 pub mutbl: hir::Mutability,
966 impl<'tcx, T: Debug> Debug for ValidationOperand<'tcx, T> {
967 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
968 write!(fmt, "{:?}: {:?}", self.lval, self.ty)?;
969 if let Some(ce) = self.re {
970 // (reuse lifetime rendering policy from ppaux.)
971 write!(fmt, "/{}", ty::ReScope(ce))?;
973 if let hir::MutImmutable = self.mutbl {
974 write!(fmt, " (imm)")?;
980 impl<'tcx> Debug for Statement<'tcx> {
981 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
982 use self::StatementKind::*;
984 Assign(ref lv, ref rv) => write!(fmt, "{:?} = {:?}", lv, rv),
985 // (reuse lifetime rendering policy from ppaux.)
986 EndRegion(ref ce) => write!(fmt, "EndRegion({})", ty::ReScope(*ce)),
987 Validate(ref op, ref lvalues) => write!(fmt, "Validate({:?}, {:?})", op, lvalues),
988 StorageLive(ref lv) => write!(fmt, "StorageLive({:?})", lv),
989 StorageDead(ref lv) => write!(fmt, "StorageDead({:?})", lv),
990 SetDiscriminant{lvalue: ref lv, variant_index: index} => {
991 write!(fmt, "discriminant({:?}) = {:?}", lv, index)
993 InlineAsm { ref asm, ref outputs, ref inputs } => {
994 write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs)
996 Nop => write!(fmt, "nop"),
1001 ///////////////////////////////////////////////////////////////////////////
1004 /// A path to a value; something that can be evaluated without
1005 /// changing or disturbing program state.
1006 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1007 pub enum Lvalue<'tcx> {
1011 /// static or static mut variable
1012 Static(Box<Static<'tcx>>),
1014 /// projection out of an lvalue (access a field, deref a pointer, etc)
1015 Projection(Box<LvalueProjection<'tcx>>),
1018 /// The def-id of a static, along with its normalized type (which is
1019 /// stored to avoid requiring normalization when reading MIR).
1020 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1021 pub struct Static<'tcx> {
1026 impl_stable_hash_for!(struct Static<'tcx> {
1031 /// The `Projection` data structure defines things of the form `B.x`
1032 /// or `*B` or `B[index]`. Note that it is parameterized because it is
1033 /// shared between `Constant` and `Lvalue`. See the aliases
1034 /// `LvalueProjection` etc below.
1035 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1036 pub struct Projection<'tcx, B, V, T> {
1038 pub elem: ProjectionElem<'tcx, V, T>,
1041 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1042 pub enum ProjectionElem<'tcx, V, T> {
1047 /// These indices are generated by slice patterns. Easiest to explain
1051 /// [X, _, .._, _, _] => { offset: 0, min_length: 4, from_end: false },
1052 /// [_, X, .._, _, _] => { offset: 1, min_length: 4, from_end: false },
1053 /// [_, _, .._, X, _] => { offset: 2, min_length: 4, from_end: true },
1054 /// [_, _, .._, _, X] => { offset: 1, min_length: 4, from_end: true },
1057 /// index or -index (in Python terms), depending on from_end
1059 /// thing being indexed must be at least this long
1061 /// counting backwards from end?
1065 /// These indices are generated by slice patterns.
1067 /// slice[from:-to] in Python terms.
1073 /// "Downcast" to a variant of an ADT. Currently, we only introduce
1074 /// this for ADTs with more than one variant. It may be better to
1075 /// just introduce it always, or always for enums.
1076 Downcast(&'tcx AdtDef, usize),
1079 /// Alias for projections as they appear in lvalues, where the base is an lvalue
1080 /// and the index is a local.
1081 pub type LvalueProjection<'tcx> = Projection<'tcx, Lvalue<'tcx>, Local, Ty<'tcx>>;
1083 /// Alias for projections as they appear in lvalues, where the base is an lvalue
1084 /// and the index is a local.
1085 pub type LvalueElem<'tcx> = ProjectionElem<'tcx, Local, Ty<'tcx>>;
1087 newtype_index!(Field, "field");
1089 impl<'tcx> Lvalue<'tcx> {
1090 pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
1091 self.elem(ProjectionElem::Field(f, ty))
1094 pub fn deref(self) -> Lvalue<'tcx> {
1095 self.elem(ProjectionElem::Deref)
1098 pub fn downcast(self, adt_def: &'tcx AdtDef, variant_index: usize) -> Lvalue<'tcx> {
1099 self.elem(ProjectionElem::Downcast(adt_def, variant_index))
1102 pub fn index(self, index: Local) -> Lvalue<'tcx> {
1103 self.elem(ProjectionElem::Index(index))
1106 pub fn elem(self, elem: LvalueElem<'tcx>) -> Lvalue<'tcx> {
1107 Lvalue::Projection(Box::new(LvalueProjection {
1114 impl<'tcx> Debug for Lvalue<'tcx> {
1115 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1116 use self::Lvalue::*;
1119 Local(id) => write!(fmt, "{:?}", id),
1120 Static(box self::Static { def_id, ty }) =>
1121 write!(fmt, "({}: {:?})", ty::tls::with(|tcx| tcx.item_path_str(def_id)), ty),
1122 Projection(ref data) =>
1124 ProjectionElem::Downcast(ref adt_def, index) =>
1125 write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name),
1126 ProjectionElem::Deref =>
1127 write!(fmt, "(*{:?})", data.base),
1128 ProjectionElem::Field(field, ty) =>
1129 write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty),
1130 ProjectionElem::Index(ref index) =>
1131 write!(fmt, "{:?}[{:?}]", data.base, index),
1132 ProjectionElem::ConstantIndex { offset, min_length, from_end: false } =>
1133 write!(fmt, "{:?}[{:?} of {:?}]", data.base, offset, min_length),
1134 ProjectionElem::ConstantIndex { offset, min_length, from_end: true } =>
1135 write!(fmt, "{:?}[-{:?} of {:?}]", data.base, offset, min_length),
1136 ProjectionElem::Subslice { from, to } if to == 0 =>
1137 write!(fmt, "{:?}[{:?}:]", data.base, from),
1138 ProjectionElem::Subslice { from, to } if from == 0 =>
1139 write!(fmt, "{:?}[:-{:?}]", data.base, to),
1140 ProjectionElem::Subslice { from, to } =>
1141 write!(fmt, "{:?}[{:?}:-{:?}]", data.base,
1149 ///////////////////////////////////////////////////////////////////////////
1152 newtype_index!(VisibilityScope, "scope");
1153 pub const ARGUMENT_VISIBILITY_SCOPE : VisibilityScope = VisibilityScope(0);
1155 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
1156 pub struct VisibilityScopeData {
1158 pub parent_scope: Option<VisibilityScope>,
1161 ///////////////////////////////////////////////////////////////////////////
1164 /// These are values that can appear inside an rvalue (or an index
1165 /// lvalue). They are intentionally limited to prevent rvalues from
1166 /// being nested in one another.
1167 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
1168 pub enum Operand<'tcx> {
1169 Consume(Lvalue<'tcx>),
1170 Constant(Box<Constant<'tcx>>),
1173 impl<'tcx> Debug for Operand<'tcx> {
1174 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1175 use self::Operand::*;
1177 Constant(ref a) => write!(fmt, "{:?}", a),
1178 Consume(ref lv) => write!(fmt, "{:?}", lv),
1183 impl<'tcx> Operand<'tcx> {
1184 pub fn function_handle<'a>(
1185 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1187 substs: &'tcx Substs<'tcx>,
1190 let ty = tcx.type_of(def_id).subst(tcx, substs);
1191 Operand::Constant(box Constant {
1194 literal: Literal::Value {
1195 value: tcx.mk_const(ty::Const {
1196 val: ConstVal::Function(def_id, substs),
1205 ///////////////////////////////////////////////////////////////////////////
1208 #[derive(Clone, RustcEncodable, RustcDecodable)]
1209 pub enum Rvalue<'tcx> {
1210 /// x (either a move or copy, depending on type of x)
1214 Repeat(Operand<'tcx>, ConstUsize),
1217 Ref(Region<'tcx>, BorrowKind, Lvalue<'tcx>),
1219 /// length of a [X] or [X;n] value
1222 Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
1224 BinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
1225 CheckedBinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
1227 NullaryOp(NullOp, Ty<'tcx>),
1228 UnaryOp(UnOp, Operand<'tcx>),
1230 /// Read the discriminant of an ADT.
1232 /// Undefined (i.e. no effort is made to make it defined, but there’s no reason why it cannot
1233 /// be defined to return, say, a 0) if ADT is not an enum.
1234 Discriminant(Lvalue<'tcx>),
1236 /// Create an aggregate value, like a tuple or struct. This is
1237 /// only needed because we want to distinguish `dest = Foo { x:
1238 /// ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case
1239 /// that `Foo` has a destructor. These rvalues can be optimized
1240 /// away after type-checking and before lowering.
1241 Aggregate(Box<AggregateKind<'tcx>>, Vec<Operand<'tcx>>),
1244 #[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1248 /// Convert unique, zero-sized type for a fn to fn()
1251 /// Convert non capturing closure to fn()
1254 /// Convert safe fn() to unsafe fn()
1257 /// "Unsize" -- convert a thin-or-fat pointer to a fat pointer.
1258 /// trans must figure out the details once full monomorphization
1259 /// is known. For example, this could be used to cast from a
1260 /// `&[i32;N]` to a `&[i32]`, or a `Box<T>` to a `Box<Trait>`
1261 /// (presuming `T: Trait`).
1265 #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1266 pub enum AggregateKind<'tcx> {
1267 /// The type is of the element
1270 /// The second field is variant number (discriminant), it's equal to 0
1271 /// for struct and union expressions. The fourth field is active field
1272 /// number and is present only for union expressions.
1273 Adt(&'tcx AdtDef, usize, &'tcx Substs<'tcx>, Option<usize>),
1274 Closure(DefId, ClosureSubsts<'tcx>),
1275 Generator(DefId, ClosureSubsts<'tcx>, GeneratorInterior<'tcx>),
1278 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1280 /// The `+` operator (addition)
1282 /// The `-` operator (subtraction)
1284 /// The `*` operator (multiplication)
1286 /// The `/` operator (division)
1288 /// The `%` operator (modulus)
1290 /// The `^` operator (bitwise xor)
1292 /// The `&` operator (bitwise and)
1294 /// The `|` operator (bitwise or)
1296 /// The `<<` operator (shift left)
1298 /// The `>>` operator (shift right)
1300 /// The `==` operator (equality)
1302 /// The `<` operator (less than)
1304 /// The `<=` operator (less than or equal to)
1306 /// The `!=` operator (not equal to)
1308 /// The `>=` operator (greater than or equal to)
1310 /// The `>` operator (greater than)
1312 /// The `ptr.offset` operator
1317 pub fn is_checkable(self) -> bool {
1320 Add | Sub | Mul | Shl | Shr => true,
1326 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1328 /// Return the size of a value of that type
1330 /// Create a new uninitialized box for a value of that type
1334 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
1336 /// The `!` operator for logical inversion
1338 /// The `-` operator for negation
1342 impl<'tcx> Debug for Rvalue<'tcx> {
1343 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1344 use self::Rvalue::*;
1347 Use(ref lvalue) => write!(fmt, "{:?}", lvalue),
1348 Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b),
1349 Len(ref a) => write!(fmt, "Len({:?})", a),
1350 Cast(ref kind, ref lv, ref ty) => write!(fmt, "{:?} as {:?} ({:?})", lv, ty, kind),
1351 BinaryOp(ref op, ref a, ref b) => write!(fmt, "{:?}({:?}, {:?})", op, a, b),
1352 CheckedBinaryOp(ref op, ref a, ref b) => {
1353 write!(fmt, "Checked{:?}({:?}, {:?})", op, a, b)
1355 UnaryOp(ref op, ref a) => write!(fmt, "{:?}({:?})", op, a),
1356 Discriminant(ref lval) => write!(fmt, "discriminant({:?})", lval),
1357 NullaryOp(ref op, ref t) => write!(fmt, "{:?}({:?})", op, t),
1358 Ref(region, borrow_kind, ref lv) => {
1359 let kind_str = match borrow_kind {
1360 BorrowKind::Shared => "",
1361 BorrowKind::Mut | BorrowKind::Unique => "mut ",
1364 // When printing regions, add trailing space if necessary.
1365 let region = if ppaux::verbose() || ppaux::identify_regions() {
1366 let mut region = format!("{}", region);
1367 if region.len() > 0 { region.push(' '); }
1370 // Do not even print 'static
1373 write!(fmt, "&{}{}{:?}", region, kind_str, lv)
1376 Aggregate(ref kind, ref lvs) => {
1377 fn fmt_tuple(fmt: &mut Formatter, lvs: &[Operand]) -> fmt::Result {
1378 let mut tuple_fmt = fmt.debug_tuple("");
1380 tuple_fmt.field(lv);
1386 AggregateKind::Array(_) => write!(fmt, "{:?}", lvs),
1388 AggregateKind::Tuple => {
1390 0 => write!(fmt, "()"),
1391 1 => write!(fmt, "({:?},)", lvs[0]),
1392 _ => fmt_tuple(fmt, lvs),
1396 AggregateKind::Adt(adt_def, variant, substs, _) => {
1397 let variant_def = &adt_def.variants[variant];
1399 ppaux::parameterized(fmt, substs, variant_def.did, &[])?;
1401 match variant_def.ctor_kind {
1402 CtorKind::Const => Ok(()),
1403 CtorKind::Fn => fmt_tuple(fmt, lvs),
1404 CtorKind::Fictive => {
1405 let mut struct_fmt = fmt.debug_struct("");
1406 for (field, lv) in variant_def.fields.iter().zip(lvs) {
1407 struct_fmt.field(&field.name.as_str(), lv);
1414 AggregateKind::Closure(def_id, _) => ty::tls::with(|tcx| {
1415 if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
1416 let name = if tcx.sess.opts.debugging_opts.span_free_formats {
1417 format!("[closure@{:?}]", node_id)
1419 format!("[closure@{:?}]", tcx.hir.span(node_id))
1421 let mut struct_fmt = fmt.debug_struct(&name);
1423 tcx.with_freevars(node_id, |freevars| {
1424 for (freevar, lv) in freevars.iter().zip(lvs) {
1425 let var_name = tcx.hir.name(freevar.var_id());
1426 struct_fmt.field(&var_name.as_str(), lv);
1432 write!(fmt, "[closure]")
1436 AggregateKind::Generator(def_id, _, _) => ty::tls::with(|tcx| {
1437 if let Some(node_id) = tcx.hir.as_local_node_id(def_id) {
1438 let name = format!("[generator@{:?}]", tcx.hir.span(node_id));
1439 let mut struct_fmt = fmt.debug_struct(&name);
1441 tcx.with_freevars(node_id, |freevars| {
1442 for (freevar, lv) in freevars.iter().zip(lvs) {
1443 let var_name = tcx.hir.name(freevar.var_id());
1444 struct_fmt.field(&var_name.as_str(), lv);
1446 struct_fmt.field("$state", &lvs[freevars.len()]);
1447 for i in (freevars.len() + 1)..lvs.len() {
1448 struct_fmt.field(&format!("${}", i - freevars.len() - 1),
1455 write!(fmt, "[generator]")
1464 ///////////////////////////////////////////////////////////////////////////
1467 /// Two constants are equal if they are the same constant. Note that
1468 /// this does not necessarily mean that they are "==" in Rust -- in
1469 /// particular one must be wary of `NaN`!
1471 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1472 pub struct Constant<'tcx> {
1475 pub literal: Literal<'tcx>,
1478 newtype_index!(Promoted, "promoted");
1480 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
1481 pub enum Literal<'tcx> {
1483 value: &'tcx ty::Const<'tcx>,
1486 // Index into the `promoted` vector of `Mir`.
1491 impl<'tcx> Debug for Constant<'tcx> {
1492 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1493 write!(fmt, "{:?}", self.literal)
1497 impl<'tcx> Debug for Literal<'tcx> {
1498 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
1499 use self::Literal::*;
1501 Value { value } => {
1502 write!(fmt, "const ")?;
1503 fmt_const_val(fmt, &value.val)
1505 Promoted { index } => {
1506 write!(fmt, "{:?}", index)
1512 /// Write a `ConstVal` in a way closer to the original source code than the `Debug` output.
1513 fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ConstVal) -> fmt::Result {
1514 use middle::const_val::ConstVal::*;
1516 Float(f) => write!(fmt, "{:?}", f),
1517 Integral(n) => write!(fmt, "{}", n),
1518 Str(s) => write!(fmt, "{:?}", s),
1520 let escaped: String = bytes.data
1522 .flat_map(|&ch| ascii::escape_default(ch).map(|c| c as char))
1524 write!(fmt, "b\"{}\"", escaped)
1526 Bool(b) => write!(fmt, "{:?}", b),
1527 Char(c) => write!(fmt, "{:?}", c),
1529 Function(def_id, _) => write!(fmt, "{}", item_path_str(def_id)),
1530 Aggregate(_) => bug!("`ConstVal::{:?}` should not be in MIR", const_val),
1531 Unevaluated(..) => write!(fmt, "{:?}", const_val)
1535 fn item_path_str(def_id: DefId) -> String {
1536 ty::tls::with(|tcx| tcx.item_path_str(def_id))
1539 impl<'tcx> ControlFlowGraph for Mir<'tcx> {
1541 type Node = BasicBlock;
1543 fn num_nodes(&self) -> usize { self.basic_blocks.len() }
1545 fn start_node(&self) -> Self::Node { START_BLOCK }
1547 fn predecessors<'graph>(&'graph self, node: Self::Node)
1548 -> <Self as GraphPredecessors<'graph>>::Iter
1550 self.predecessors_for(node).clone().into_iter()
1552 fn successors<'graph>(&'graph self, node: Self::Node)
1553 -> <Self as GraphSuccessors<'graph>>::Iter
1555 self.basic_blocks[node].terminator().successors().into_owned().into_iter()
1559 impl<'a, 'b> GraphPredecessors<'b> for Mir<'a> {
1560 type Item = BasicBlock;
1561 type Iter = IntoIter<BasicBlock>;
1564 impl<'a, 'b> GraphSuccessors<'b> for Mir<'a> {
1565 type Item = BasicBlock;
1566 type Iter = IntoIter<BasicBlock>;
1569 #[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)]
1570 pub struct Location {
1571 /// the location is within this block
1572 pub block: BasicBlock,
1574 /// the location is the start of the this statement; or, if `statement_index`
1575 /// == num-statements, then the start of the terminator.
1576 pub statement_index: usize,
1579 impl fmt::Debug for Location {
1580 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
1581 write!(fmt, "{:?}[{}]", self.block, self.statement_index)
1586 pub fn dominates(&self, other: &Location, dominators: &Dominators<BasicBlock>) -> bool {
1587 if self.block == other.block {
1588 self.statement_index <= other.statement_index
1590 dominators.is_dominated_by(other.block, self.block)
1595 /// The layout of generator state
1596 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
1597 pub struct GeneratorLayout<'tcx> {
1598 pub fields: Vec<LocalDecl<'tcx>>,
1602 * TypeFoldable implementations for MIR types
1605 impl<'tcx> TypeFoldable<'tcx> for Mir<'tcx> {
1606 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1608 basic_blocks: self.basic_blocks.fold_with(folder),
1609 visibility_scopes: self.visibility_scopes.clone(),
1610 promoted: self.promoted.fold_with(folder),
1611 return_ty: self.return_ty.fold_with(folder),
1612 yield_ty: self.yield_ty.fold_with(folder),
1613 generator_drop: self.generator_drop.fold_with(folder),
1614 generator_layout: self.generator_layout.fold_with(folder),
1615 local_decls: self.local_decls.fold_with(folder),
1616 arg_count: self.arg_count,
1617 upvar_decls: self.upvar_decls.clone(),
1618 spread_arg: self.spread_arg,
1620 cache: cache::Cache::new()
1624 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1625 self.basic_blocks.visit_with(visitor) ||
1626 self.generator_drop.visit_with(visitor) ||
1627 self.generator_layout.visit_with(visitor) ||
1628 self.yield_ty.visit_with(visitor) ||
1629 self.promoted.visit_with(visitor) ||
1630 self.return_ty.visit_with(visitor) ||
1631 self.local_decls.visit_with(visitor)
1635 impl<'tcx> TypeFoldable<'tcx> for GeneratorLayout<'tcx> {
1636 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1638 fields: self.fields.fold_with(folder),
1642 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1643 self.fields.visit_with(visitor)
1647 impl<'tcx> TypeFoldable<'tcx> for LocalDecl<'tcx> {
1648 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1650 ty: self.ty.fold_with(folder),
1655 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1656 self.ty.visit_with(visitor)
1660 impl<'tcx> TypeFoldable<'tcx> for BasicBlockData<'tcx> {
1661 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1663 statements: self.statements.fold_with(folder),
1664 terminator: self.terminator.fold_with(folder),
1665 is_cleanup: self.is_cleanup
1669 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1670 self.statements.visit_with(visitor) || self.terminator.visit_with(visitor)
1674 impl<'tcx> TypeFoldable<'tcx> for ValidationOperand<'tcx, Lvalue<'tcx>> {
1675 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1677 lval: self.lval.fold_with(folder),
1678 ty: self.ty.fold_with(folder),
1684 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1685 self.lval.visit_with(visitor) || self.ty.visit_with(visitor)
1689 impl<'tcx> TypeFoldable<'tcx> for Statement<'tcx> {
1690 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1691 use mir::StatementKind::*;
1693 let kind = match self.kind {
1694 Assign(ref lval, ref rval) => Assign(lval.fold_with(folder), rval.fold_with(folder)),
1695 SetDiscriminant { ref lvalue, variant_index } => SetDiscriminant {
1696 lvalue: lvalue.fold_with(folder),
1699 StorageLive(ref local) => StorageLive(local.fold_with(folder)),
1700 StorageDead(ref local) => StorageDead(local.fold_with(folder)),
1701 InlineAsm { ref asm, ref outputs, ref inputs } => InlineAsm {
1703 outputs: outputs.fold_with(folder),
1704 inputs: inputs.fold_with(folder)
1707 // Note for future: If we want to expose the region scopes
1708 // during the fold, we need to either generalize EndRegion
1709 // to carry `[ty::Region]`, or extend the `TypeFolder`
1710 // trait with a `fn fold_scope`.
1711 EndRegion(ref region_scope) => EndRegion(region_scope.clone()),
1713 Validate(ref op, ref lvals) =>
1714 Validate(op.clone(),
1715 lvals.iter().map(|operand| operand.fold_with(folder)).collect()),
1720 source_info: self.source_info,
1725 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1726 use mir::StatementKind::*;
1729 Assign(ref lval, ref rval) => { lval.visit_with(visitor) || rval.visit_with(visitor) }
1730 SetDiscriminant { ref lvalue, .. } => lvalue.visit_with(visitor),
1731 StorageLive(ref local) |
1732 StorageDead(ref local) => local.visit_with(visitor),
1733 InlineAsm { ref outputs, ref inputs, .. } =>
1734 outputs.visit_with(visitor) || inputs.visit_with(visitor),
1736 // Note for future: If we want to expose the region scopes
1737 // during the visit, we need to either generalize EndRegion
1738 // to carry `[ty::Region]`, or extend the `TypeVisitor`
1739 // trait with a `fn visit_scope`.
1740 EndRegion(ref _scope) => false,
1742 Validate(ref _op, ref lvalues) =>
1743 lvalues.iter().any(|ty_and_lvalue| ty_and_lvalue.visit_with(visitor)),
1750 impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> {
1751 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1752 use mir::TerminatorKind::*;
1754 let kind = match self.kind {
1755 Goto { target } => Goto { target: target },
1756 SwitchInt { ref discr, switch_ty, ref values, ref targets } => SwitchInt {
1757 discr: discr.fold_with(folder),
1758 switch_ty: switch_ty.fold_with(folder),
1759 values: values.clone(),
1760 targets: targets.clone()
1762 Drop { ref location, target, unwind } => Drop {
1763 location: location.fold_with(folder),
1767 DropAndReplace { ref location, ref value, target, unwind } => DropAndReplace {
1768 location: location.fold_with(folder),
1769 value: value.fold_with(folder),
1773 Yield { ref value, resume, drop } => Yield {
1774 value: value.fold_with(folder),
1778 Call { ref func, ref args, ref destination, cleanup } => {
1779 let dest = destination.as_ref().map(|&(ref loc, dest)| {
1780 (loc.fold_with(folder), dest)
1784 func: func.fold_with(folder),
1785 args: args.fold_with(folder),
1790 Assert { ref cond, expected, ref msg, target, cleanup } => {
1791 let msg = if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
1792 AssertMessage::BoundsCheck {
1793 len: len.fold_with(folder),
1794 index: index.fold_with(folder),
1800 cond: cond.fold_with(folder),
1807 GeneratorDrop => GeneratorDrop,
1810 Unreachable => Unreachable,
1813 source_info: self.source_info,
1818 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1819 use mir::TerminatorKind::*;
1822 SwitchInt { ref discr, switch_ty, .. } =>
1823 discr.visit_with(visitor) || switch_ty.visit_with(visitor),
1824 Drop { ref location, ..} => location.visit_with(visitor),
1825 DropAndReplace { ref location, ref value, ..} =>
1826 location.visit_with(visitor) || value.visit_with(visitor),
1827 Yield { ref value, ..} =>
1828 value.visit_with(visitor),
1829 Call { ref func, ref args, ref destination, .. } => {
1830 let dest = if let Some((ref loc, _)) = *destination {
1831 loc.visit_with(visitor)
1833 dest || func.visit_with(visitor) || args.visit_with(visitor)
1835 Assert { ref cond, ref msg, .. } => {
1836 if cond.visit_with(visitor) {
1837 if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
1838 len.visit_with(visitor) || index.visit_with(visitor)
1850 Unreachable => false
1855 impl<'tcx> TypeFoldable<'tcx> for Lvalue<'tcx> {
1856 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1858 &Lvalue::Projection(ref p) => Lvalue::Projection(p.fold_with(folder)),
1863 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1864 if let &Lvalue::Projection(ref p) = self {
1865 p.visit_with(visitor)
1872 impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> {
1873 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1876 Use(ref op) => Use(op.fold_with(folder)),
1877 Repeat(ref op, len) => Repeat(op.fold_with(folder), len),
1878 Ref(region, bk, ref lval) => Ref(region.fold_with(folder), bk, lval.fold_with(folder)),
1879 Len(ref lval) => Len(lval.fold_with(folder)),
1880 Cast(kind, ref op, ty) => Cast(kind, op.fold_with(folder), ty.fold_with(folder)),
1881 BinaryOp(op, ref rhs, ref lhs) =>
1882 BinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
1883 CheckedBinaryOp(op, ref rhs, ref lhs) =>
1884 CheckedBinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
1885 UnaryOp(op, ref val) => UnaryOp(op, val.fold_with(folder)),
1886 Discriminant(ref lval) => Discriminant(lval.fold_with(folder)),
1887 NullaryOp(op, ty) => NullaryOp(op, ty.fold_with(folder)),
1888 Aggregate(ref kind, ref fields) => {
1889 let kind = box match **kind {
1890 AggregateKind::Array(ty) => AggregateKind::Array(ty.fold_with(folder)),
1891 AggregateKind::Tuple => AggregateKind::Tuple,
1892 AggregateKind::Adt(def, v, substs, n) =>
1893 AggregateKind::Adt(def, v, substs.fold_with(folder), n),
1894 AggregateKind::Closure(id, substs) =>
1895 AggregateKind::Closure(id, substs.fold_with(folder)),
1896 AggregateKind::Generator(id, substs, interior) =>
1897 AggregateKind::Generator(id,
1898 substs.fold_with(folder),
1899 interior.fold_with(folder)),
1901 Aggregate(kind, fields.fold_with(folder))
1906 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1909 Use(ref op) => op.visit_with(visitor),
1910 Repeat(ref op, _) => op.visit_with(visitor),
1911 Ref(region, _, ref lval) => region.visit_with(visitor) || lval.visit_with(visitor),
1912 Len(ref lval) => lval.visit_with(visitor),
1913 Cast(_, ref op, ty) => op.visit_with(visitor) || ty.visit_with(visitor),
1914 BinaryOp(_, ref rhs, ref lhs) |
1915 CheckedBinaryOp(_, ref rhs, ref lhs) =>
1916 rhs.visit_with(visitor) || lhs.visit_with(visitor),
1917 UnaryOp(_, ref val) => val.visit_with(visitor),
1918 Discriminant(ref lval) => lval.visit_with(visitor),
1919 NullaryOp(_, ty) => ty.visit_with(visitor),
1920 Aggregate(ref kind, ref fields) => {
1922 AggregateKind::Array(ty) => ty.visit_with(visitor),
1923 AggregateKind::Tuple => false,
1924 AggregateKind::Adt(_, _, substs, _) => substs.visit_with(visitor),
1925 AggregateKind::Closure(_, substs) => substs.visit_with(visitor),
1926 AggregateKind::Generator(_, substs, interior) => substs.visit_with(visitor) ||
1927 interior.visit_with(visitor),
1928 }) || fields.visit_with(visitor)
1934 impl<'tcx> TypeFoldable<'tcx> for Operand<'tcx> {
1935 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1937 Operand::Consume(ref lval) => Operand::Consume(lval.fold_with(folder)),
1938 Operand::Constant(ref c) => Operand::Constant(c.fold_with(folder)),
1942 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1944 Operand::Consume(ref lval) => lval.visit_with(visitor),
1945 Operand::Constant(ref c) => c.visit_with(visitor)
1950 impl<'tcx, B, V, T> TypeFoldable<'tcx> for Projection<'tcx, B, V, T>
1951 where B: TypeFoldable<'tcx>, V: TypeFoldable<'tcx>, T: TypeFoldable<'tcx>
1953 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1954 use mir::ProjectionElem::*;
1956 let base = self.base.fold_with(folder);
1957 let elem = match self.elem {
1959 Field(f, ref ty) => Field(f, ty.fold_with(folder)),
1960 Index(ref v) => Index(v.fold_with(folder)),
1961 ref elem => elem.clone()
1970 fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool {
1971 use mir::ProjectionElem::*;
1973 self.base.visit_with(visitor) ||
1975 Field(_, ref ty) => ty.visit_with(visitor),
1976 Index(ref v) => v.visit_with(visitor),
1982 impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> {
1983 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1985 span: self.span.clone(),
1986 ty: self.ty.fold_with(folder),
1987 literal: self.literal.fold_with(folder)
1990 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
1991 self.ty.visit_with(visitor) || self.literal.visit_with(visitor)
1995 impl<'tcx> TypeFoldable<'tcx> for Literal<'tcx> {
1996 fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
1998 Literal::Value { value } => Literal::Value {
1999 value: value.fold_with(folder)
2001 Literal::Promoted { index } => Literal::Promoted { index }
2004 fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
2006 Literal::Value { value } => value.visit_with(visitor),
2007 Literal::Promoted { .. } => false