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 use graphviz::IntoCow;
12 use middle::const_val::ConstVal;
13 use rustc_const_math::{ConstUsize, ConstInt};
14 use hir::def_id::DefId;
15 use ty::subst::Substs;
16 use ty::{self, AdtDef, ClosureSubsts, FnOutput, Region, Ty};
18 use rustc_back::slice;
21 use std::borrow::{Cow};
22 use std::fmt::{self, Debug, Formatter, Write};
24 use std::ops::{Index, IndexMut};
25 use syntax::ast::{self, Name};
26 use syntax::codemap::Span;
28 /// Lowered representation of a single function.
29 #[derive(Clone, RustcEncodable, RustcDecodable)]
30 pub struct Mir<'tcx> {
31 /// List of basic blocks. References to basic block use a newtyped index type `BasicBlock`
32 /// that indexes into this vector.
33 pub basic_blocks: Vec<BasicBlockData<'tcx>>,
35 /// List of lexical scopes; these are referenced by statements and
36 /// used (eventually) for debuginfo. Indexed by a `ScopeId`.
37 pub scopes: Vec<ScopeData>,
39 /// Return type of the function.
40 pub return_ty: FnOutput<'tcx>,
42 /// Variables: these are stack slots corresponding to user variables. They may be
43 /// assigned many times.
44 pub var_decls: Vec<VarDecl<'tcx>>,
46 /// Args: these are stack slots corresponding to the input arguments.
47 pub arg_decls: Vec<ArgDecl<'tcx>>,
49 /// Temp declarations: stack slots that for temporaries created by
50 /// the compiler. These are assigned once, but they are not SSA
51 /// values in that it is possible to borrow them and mutate them
52 /// through the resulting reference.
53 pub temp_decls: Vec<TempDecl<'tcx>>,
55 /// A span representing this MIR, for error reporting
59 /// where execution begins
60 pub const START_BLOCK: BasicBlock = BasicBlock(0);
62 /// where execution ends, on normal return
63 pub const END_BLOCK: BasicBlock = BasicBlock(1);
65 impl<'tcx> Mir<'tcx> {
66 pub fn all_basic_blocks(&self) -> Vec<BasicBlock> {
67 (0..self.basic_blocks.len())
68 .map(|i| BasicBlock::new(i))
72 pub fn basic_block_data(&self, bb: BasicBlock) -> &BasicBlockData<'tcx> {
73 &self.basic_blocks[bb.index()]
76 pub fn basic_block_data_mut(&mut self, bb: BasicBlock) -> &mut BasicBlockData<'tcx> {
77 &mut self.basic_blocks[bb.index()]
81 impl<'tcx> Index<BasicBlock> for Mir<'tcx> {
82 type Output = BasicBlockData<'tcx>;
85 fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> {
86 self.basic_block_data(index)
90 impl<'tcx> IndexMut<BasicBlock> for Mir<'tcx> {
92 fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> {
93 self.basic_block_data_mut(index)
97 ///////////////////////////////////////////////////////////////////////////
98 // Mutability and borrow kinds
100 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
101 pub enum Mutability {
106 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
107 pub enum BorrowKind {
108 /// Data must be immutable and is aliasable.
111 /// Data must be immutable but not aliasable. This kind of borrow
112 /// cannot currently be expressed by the user and is used only in
113 /// implicit closure bindings. It is needed when you the closure
114 /// is borrowing or mutating a mutable referent, e.g.:
116 /// let x: &mut isize = ...;
117 /// let y = || *x += 5;
119 /// If we were to try to translate this closure into a more explicit
120 /// form, we'd encounter an error with the code as written:
122 /// struct Env { x: & &mut isize }
123 /// let x: &mut isize = ...;
124 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
125 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
127 /// This is then illegal because you cannot mutate a `&mut` found
128 /// in an aliasable location. To solve, you'd have to translate with
129 /// an `&mut` borrow:
131 /// struct Env { x: & &mut isize }
132 /// let x: &mut isize = ...;
133 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
134 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
136 /// Now the assignment to `**env.x` is legal, but creating a
137 /// mutable pointer to `x` is not because `x` is not mutable. We
138 /// could fix this by declaring `x` as `let mut x`. This is ok in
139 /// user code, if awkward, but extra weird for closures, since the
140 /// borrow is hidden.
142 /// So we introduce a "unique imm" borrow -- the referent is
143 /// immutable, but not aliasable. This solves the problem. For
144 /// simplicity, we don't give users the way to express this
145 /// borrow, it's just used when translating closures.
148 /// Data is mutable and not aliasable.
152 ///////////////////////////////////////////////////////////////////////////
153 // Variables and temps
155 /// A "variable" is a binding declared by the user as part of the fn
156 /// decl, a let, etc.
157 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
158 pub struct VarDecl<'tcx> {
159 /// `let mut x` vs `let x`
160 pub mutability: Mutability,
162 /// name that user gave the variable; not that, internally,
163 /// mir references variables by index
166 /// type inferred for this variable (`let x: ty = ...`)
169 /// scope in which variable was declared
172 /// span where variable was declared
176 /// A "temp" is a temporary that we place on the stack. They are
177 /// anonymous, always mutable, and have only a type.
178 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
179 pub struct TempDecl<'tcx> {
183 /// A "arg" is one of the function's formal arguments. These are
184 /// anonymous and distinct from the bindings that the user declares.
186 /// For example, in this function:
189 /// fn foo((x, y): (i32, u32)) { ... }
192 /// there is only one argument, of type `(i32, u32)`, but two bindings
194 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
195 pub struct ArgDecl<'tcx> {
198 /// If true, this argument is a tuple after monomorphization,
199 /// and has to be collected from multiple actual arguments.
203 ///////////////////////////////////////////////////////////////////////////
206 /// The index of a particular basic block. The index is into the `basic_blocks`
207 /// list of the `Mir`.
209 /// (We use a `u32` internally just to save memory.)
210 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
211 pub struct BasicBlock(u32);
214 pub fn new(index: usize) -> BasicBlock {
215 assert!(index < (u32::MAX as usize));
216 BasicBlock(index as u32)
219 /// Extract the index.
220 pub fn index(self) -> usize {
225 impl Debug for BasicBlock {
226 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
227 write!(fmt, "bb{}", self.0)
231 ///////////////////////////////////////////////////////////////////////////
232 // BasicBlockData and Terminator
234 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
235 pub struct BasicBlockData<'tcx> {
236 /// List of statements in this block.
237 pub statements: Vec<Statement<'tcx>>,
239 /// Terminator for this block.
241 /// NB. This should generally ONLY be `None` during construction.
242 /// Therefore, you should generally access it via the
243 /// `terminator()` or `terminator_mut()` methods. The only
244 /// exception is that certain passes, such as `simplify_cfg`, swap
245 /// out the terminator temporarily with `None` while they continue
246 /// to recurse over the set of basic blocks.
247 pub terminator: Option<Terminator<'tcx>>,
249 /// If true, this block lies on an unwind path. This is used
250 /// during trans where distinct kinds of basic blocks may be
251 /// generated (particularly for MSVC cleanup). Unwind blocks must
252 /// only branch to other unwind blocks.
253 pub is_cleanup: bool,
256 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
257 pub struct Terminator<'tcx> {
260 pub kind: TerminatorKind<'tcx>
263 #[derive(Clone, RustcEncodable, RustcDecodable)]
264 pub enum TerminatorKind<'tcx> {
265 /// block should have one successor in the graph; we jump there
270 /// jump to branch 0 if this lvalue evaluates to true
273 targets: (BasicBlock, BasicBlock),
276 /// lvalue evaluates to some enum; jump depending on the branch
279 adt_def: AdtDef<'tcx>,
280 targets: Vec<BasicBlock>,
283 /// operand evaluates to an integer; jump depending on its value
284 /// to one of the targets, and otherwise fallback to `otherwise`
286 /// discriminant value being tested
289 /// type of value being tested
292 /// Possible values. The locations to branch to in each case
293 /// are found in the corresponding indices from the `targets` vector.
294 values: Vec<ConstVal>,
296 /// Possible branch sites. The length of this vector should be
297 /// equal to the length of the `values` vector plus 1 -- the
298 /// extra item is the block to branch to if none of the values
300 targets: Vec<BasicBlock>,
303 /// Indicates that the landing pad is finished and unwinding should
304 /// continue. Emitted by build::scope::diverge_cleanup.
307 /// Indicates a normal return. The ReturnPointer lvalue should
308 /// have been filled in by now. This should only occur in the
316 unwind: Option<BasicBlock>
319 /// Block ends with a call of a converging function
321 /// The function that’s being called
323 /// Arguments the function is called with
324 args: Vec<Operand<'tcx>>,
325 /// Destination for the return value. If some, the call is converging.
326 destination: Option<(Lvalue<'tcx>, BasicBlock)>,
327 /// Cleanups to be done if the call unwinds.
328 cleanup: Option<BasicBlock>
332 impl<'tcx> Terminator<'tcx> {
333 pub fn successors(&self) -> Cow<[BasicBlock]> {
334 self.kind.successors()
337 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
338 self.kind.successors_mut()
342 impl<'tcx> TerminatorKind<'tcx> {
343 pub fn successors(&self) -> Cow<[BasicBlock]> {
344 use self::TerminatorKind::*;
346 Goto { target: ref b } => slice::ref_slice(b).into_cow(),
347 If { targets: (b1, b2), .. } => vec![b1, b2].into_cow(),
348 Switch { targets: ref b, .. } => b[..].into_cow(),
349 SwitchInt { targets: ref b, .. } => b[..].into_cow(),
350 Resume => (&[]).into_cow(),
351 Return => (&[]).into_cow(),
352 Call { destination: Some((_, t)), cleanup: Some(c), .. } => vec![t, c].into_cow(),
353 Call { destination: Some((_, ref t)), cleanup: None, .. } =>
354 slice::ref_slice(t).into_cow(),
355 Call { destination: None, cleanup: Some(ref c), .. } => slice::ref_slice(c).into_cow(),
356 Call { destination: None, cleanup: None, .. } => (&[]).into_cow(),
357 Drop { target, unwind: Some(unwind), .. } => vec![target, unwind].into_cow(),
358 Drop { ref target, .. } => slice::ref_slice(target).into_cow(),
362 // FIXME: no mootable cow. I’m honestly not sure what a “cow” between `&mut [BasicBlock]` and
363 // `Vec<&mut BasicBlock>` would look like in the first place.
364 pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
365 use self::TerminatorKind::*;
367 Goto { target: ref mut b } => vec![b],
368 If { targets: (ref mut b1, ref mut b2), .. } => vec![b1, b2],
369 Switch { targets: ref mut b, .. } => b.iter_mut().collect(),
370 SwitchInt { targets: ref mut b, .. } => b.iter_mut().collect(),
371 Resume => Vec::new(),
372 Return => Vec::new(),
373 Call { destination: Some((_, ref mut t)), cleanup: Some(ref mut c), .. } => vec![t, c],
374 Call { destination: Some((_, ref mut t)), cleanup: None, .. } => vec![t],
375 Call { destination: None, cleanup: Some(ref mut c), .. } => vec![c],
376 Call { destination: None, cleanup: None, .. } => vec![],
377 Drop { ref mut target, unwind: Some(ref mut unwind), .. } => vec![target, unwind],
378 Drop { ref mut target, .. } => vec![target]
383 impl<'tcx> BasicBlockData<'tcx> {
384 pub fn new(terminator: Option<Terminator<'tcx>>) -> BasicBlockData<'tcx> {
387 terminator: terminator,
392 /// Accessor for terminator.
394 /// Terminator may not be None after construction of the basic block is complete. This accessor
395 /// provides a convenience way to reach the terminator.
396 pub fn terminator(&self) -> &Terminator<'tcx> {
397 self.terminator.as_ref().expect("invalid terminator state")
400 pub fn terminator_mut(&mut self) -> &mut Terminator<'tcx> {
401 self.terminator.as_mut().expect("invalid terminator state")
405 impl<'tcx> Debug for TerminatorKind<'tcx> {
406 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
408 let successors = self.successors();
409 let labels = self.fmt_successor_labels();
410 assert_eq!(successors.len(), labels.len());
412 match successors.len() {
415 1 => write!(fmt, " -> {:?}", successors[0]),
418 write!(fmt, " -> [")?;
419 for (i, target) in successors.iter().enumerate() {
423 write!(fmt, "{}: {:?}", labels[i], target)?;
432 impl<'tcx> TerminatorKind<'tcx> {
433 /// Write the "head" part of the terminator; that is, its name and the data it uses to pick the
434 /// successor basic block, if any. The only information not inlcuded is the list of possible
435 /// successors, which may be rendered differently between the text and the graphviz format.
436 pub fn fmt_head<W: Write>(&self, fmt: &mut W) -> fmt::Result {
437 use self::TerminatorKind::*;
439 Goto { .. } => write!(fmt, "goto"),
440 If { cond: ref lv, .. } => write!(fmt, "if({:?})", lv),
441 Switch { discr: ref lv, .. } => write!(fmt, "switch({:?})", lv),
442 SwitchInt { discr: ref lv, .. } => write!(fmt, "switchInt({:?})", lv),
443 Return => write!(fmt, "return"),
444 Resume => write!(fmt, "resume"),
445 Drop { ref value, .. } => write!(fmt, "drop({:?})", value),
446 Call { ref func, ref args, ref destination, .. } => {
447 if let Some((ref destination, _)) = *destination {
448 write!(fmt, "{:?} = ", destination)?;
450 write!(fmt, "{:?}(", func)?;
451 for (index, arg) in args.iter().enumerate() {
455 write!(fmt, "{:?}", arg)?;
462 /// Return the list of labels for the edges to the successor basic blocks.
463 pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
464 use self::TerminatorKind::*;
466 Return | Resume => vec![],
467 Goto { .. } => vec!["".into()],
468 If { .. } => vec!["true".into(), "false".into()],
469 Switch { ref adt_def, .. } => {
472 .map(|variant| variant.name.to_string().into())
475 SwitchInt { ref values, .. } => {
478 let mut buf = String::new();
479 fmt_const_val(&mut buf, const_val).unwrap();
482 .chain(iter::once(String::from("otherwise").into()))
485 Call { destination: Some(_), cleanup: Some(_), .. } =>
486 vec!["return".into_cow(), "unwind".into_cow()],
487 Call { destination: Some(_), cleanup: None, .. } => vec!["return".into_cow()],
488 Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into_cow()],
489 Call { destination: None, cleanup: None, .. } => vec![],
490 Drop { unwind: None, .. } => vec!["return".into_cow()],
491 Drop { .. } => vec!["return".into_cow(), "unwind".into_cow()],
497 ///////////////////////////////////////////////////////////////////////////
500 #[derive(Clone, RustcEncodable, RustcDecodable)]
501 pub struct Statement<'tcx> {
504 pub kind: StatementKind<'tcx>,
507 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
508 pub enum StatementKind<'tcx> {
509 Assign(Lvalue<'tcx>, Rvalue<'tcx>),
512 impl<'tcx> Debug for Statement<'tcx> {
513 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
514 use self::StatementKind::*;
516 Assign(ref lv, ref rv) => write!(fmt, "{:?} = {:?}", lv, rv)
521 ///////////////////////////////////////////////////////////////////////////
524 /// A path to a value; something that can be evaluated without
525 /// changing or disturbing program state.
526 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
527 pub enum Lvalue<'tcx> {
528 /// local variable declared by the user
531 /// temporary introduced during lowering into MIR
534 /// formal parameter of the function; note that these are NOT the
535 /// bindings that the user declares, which are vars
538 /// static or static mut variable
541 /// the return pointer of the fn
544 /// projection out of an lvalue (access a field, deref a pointer, etc)
545 Projection(Box<LvalueProjection<'tcx>>),
548 /// The `Projection` data structure defines things of the form `B.x`
549 /// or `*B` or `B[index]`. Note that it is parameterized because it is
550 /// shared between `Constant` and `Lvalue`. See the aliases
551 /// `LvalueProjection` etc below.
552 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
553 pub struct Projection<'tcx, B, V> {
555 pub elem: ProjectionElem<'tcx, V>,
558 #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
559 pub enum ProjectionElem<'tcx, V> {
561 Field(Field, Ty<'tcx>),
564 /// These indices are generated by slice patterns. Easiest to explain
568 /// [X, _, .._, _, _] => { offset: 0, min_length: 4, from_end: false },
569 /// [_, X, .._, _, _] => { offset: 1, min_length: 4, from_end: false },
570 /// [_, _, .._, X, _] => { offset: 2, min_length: 4, from_end: true },
571 /// [_, _, .._, _, X] => { offset: 1, min_length: 4, from_end: true },
574 /// index or -index (in Python terms), depending on from_end
576 /// thing being indexed must be at least this long
578 /// counting backwards from end?
582 /// "Downcast" to a variant of an ADT. Currently, we only introduce
583 /// this for ADTs with more than one variant. It may be better to
584 /// just introduce it always, or always for enums.
585 Downcast(AdtDef<'tcx>, usize),
588 /// Alias for projections as they appear in lvalues, where the base is an lvalue
589 /// and the index is an operand.
590 pub type LvalueProjection<'tcx> = Projection<'tcx, Lvalue<'tcx>, Operand<'tcx>>;
592 /// Alias for projections as they appear in lvalues, where the base is an lvalue
593 /// and the index is an operand.
594 pub type LvalueElem<'tcx> = ProjectionElem<'tcx, Operand<'tcx>>;
596 /// Index into the list of fields found in a `VariantDef`
597 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
598 pub struct Field(u32);
601 pub fn new(value: usize) -> Field {
602 assert!(value < (u32::MAX) as usize);
606 pub fn index(self) -> usize {
611 impl<'tcx> Lvalue<'tcx> {
612 pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
613 self.elem(ProjectionElem::Field(f, ty))
616 pub fn deref(self) -> Lvalue<'tcx> {
617 self.elem(ProjectionElem::Deref)
620 pub fn index(self, index: Operand<'tcx>) -> Lvalue<'tcx> {
621 self.elem(ProjectionElem::Index(index))
624 pub fn elem(self, elem: LvalueElem<'tcx>) -> Lvalue<'tcx> {
625 Lvalue::Projection(Box::new(LvalueProjection {
632 impl<'tcx> Debug for Lvalue<'tcx> {
633 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
638 write!(fmt, "var{:?}", id),
640 write!(fmt, "arg{:?}", id),
642 write!(fmt, "tmp{:?}", id),
644 write!(fmt, "{}", ty::tls::with(|tcx| tcx.item_path_str(def_id))),
646 write!(fmt, "return"),
647 Projection(ref data) =>
649 ProjectionElem::Downcast(ref adt_def, index) =>
650 write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name),
651 ProjectionElem::Deref =>
652 write!(fmt, "(*{:?})", data.base),
653 ProjectionElem::Field(field, ty) =>
654 write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty),
655 ProjectionElem::Index(ref index) =>
656 write!(fmt, "{:?}[{:?}]", data.base, index),
657 ProjectionElem::ConstantIndex { offset, min_length, from_end: false } =>
658 write!(fmt, "{:?}[{:?} of {:?}]", data.base, offset, min_length),
659 ProjectionElem::ConstantIndex { offset, min_length, from_end: true } =>
660 write!(fmt, "{:?}[-{:?} of {:?}]", data.base, offset, min_length),
666 ///////////////////////////////////////////////////////////////////////////
669 impl Index<ScopeId> for Vec<ScopeData> {
670 type Output = ScopeData;
673 fn index(&self, index: ScopeId) -> &ScopeData {
678 impl IndexMut<ScopeId> for Vec<ScopeData> {
680 fn index_mut(&mut self, index: ScopeId) -> &mut ScopeData {
681 &mut self[index.index()]
685 #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, RustcEncodable, RustcDecodable)]
686 pub struct ScopeId(u32);
689 pub fn new(index: usize) -> ScopeId {
690 assert!(index < (u32::MAX as usize));
691 ScopeId(index as u32)
694 pub fn index(self) -> usize {
699 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
700 pub struct ScopeData {
701 pub parent_scope: Option<ScopeId>,
704 ///////////////////////////////////////////////////////////////////////////
707 /// These are values that can appear inside an rvalue (or an index
708 /// lvalue). They are intentionally limited to prevent rvalues from
709 /// being nested in one another.
710 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
711 pub enum Operand<'tcx> {
712 Consume(Lvalue<'tcx>),
713 Constant(Constant<'tcx>),
716 impl<'tcx> Debug for Operand<'tcx> {
717 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
718 use self::Operand::*;
720 Constant(ref a) => write!(fmt, "{:?}", a),
721 Consume(ref lv) => write!(fmt, "{:?}", lv),
726 ///////////////////////////////////////////////////////////////////////////
729 #[derive(Clone, RustcEncodable, RustcDecodable)]
730 pub enum Rvalue<'tcx> {
731 /// x (either a move or copy, depending on type of x)
735 Repeat(Operand<'tcx>, TypedConstVal<'tcx>),
738 Ref(Region, BorrowKind, Lvalue<'tcx>),
740 /// length of a [X] or [X;n] value
743 Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
745 BinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
747 UnaryOp(UnOp, Operand<'tcx>),
749 /// Creates an *uninitialized* Box
752 /// Create an aggregate value, like a tuple or struct. This is
753 /// only needed because we want to distinguish `dest = Foo { x:
754 /// ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case
755 /// that `Foo` has a destructor. These rvalues can be optimized
756 /// away after type-checking and before lowering.
757 Aggregate(AggregateKind<'tcx>, Vec<Operand<'tcx>>),
759 /// Generates a slice of the form `&input[from_start..L-from_end]`
760 /// where `L` is the length of the slice. This is only created by
761 /// slice pattern matching, so e.g. a pattern of the form `[x, y,
762 /// .., z]` might create a slice with `from_start=2` and
772 outputs: Vec<Lvalue<'tcx>>,
773 inputs: Vec<Operand<'tcx>>
777 #[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
781 /// Convert unique, zero-sized type for a fn to fn()
784 /// Convert safe fn() to unsafe fn()
787 /// "Unsize" -- convert a thin-or-fat pointer to a fat pointer.
788 /// trans must figure out the details once full monomorphization
789 /// is known. For example, this could be used to cast from a
790 /// `&[i32;N]` to a `&[i32]`, or a `Box<T>` to a `Box<Trait>`
791 /// (presuming `T: Trait`).
795 #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
796 pub enum AggregateKind<'tcx> {
799 Adt(AdtDef<'tcx>, usize, &'tcx Substs<'tcx>),
800 Closure(DefId, &'tcx ClosureSubsts<'tcx>),
803 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
805 /// The `+` operator (addition)
807 /// The `-` operator (subtraction)
809 /// The `*` operator (multiplication)
811 /// The `/` operator (division)
813 /// The `%` operator (modulus)
815 /// The `^` operator (bitwise xor)
817 /// The `&` operator (bitwise and)
819 /// The `|` operator (bitwise or)
821 /// The `<<` operator (shift left)
823 /// The `>>` operator (shift right)
825 /// The `==` operator (equality)
827 /// The `<` operator (less than)
829 /// The `<=` operator (less than or equal to)
831 /// The `!=` operator (not equal to)
833 /// The `>=` operator (greater than or equal to)
835 /// The `>` operator (greater than)
839 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
841 /// The `!` operator for logical inversion
843 /// The `-` operator for negation
847 impl<'tcx> Debug for Rvalue<'tcx> {
848 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
852 Use(ref lvalue) => write!(fmt, "{:?}", lvalue),
853 Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b),
854 Len(ref a) => write!(fmt, "Len({:?})", a),
855 Cast(ref kind, ref lv, ref ty) => write!(fmt, "{:?} as {:?} ({:?})", lv, ty, kind),
856 BinaryOp(ref op, ref a, ref b) => write!(fmt, "{:?}({:?}, {:?})", op, a, b),
857 UnaryOp(ref op, ref a) => write!(fmt, "{:?}({:?})", op, a),
858 Box(ref t) => write!(fmt, "Box({:?})", t),
859 InlineAsm { ref asm, ref outputs, ref inputs } => {
860 write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs)
862 Slice { ref input, from_start, from_end } =>
863 write!(fmt, "{:?}[{:?}..-{:?}]", input, from_start, from_end),
865 Ref(_, borrow_kind, ref lv) => {
866 let kind_str = match borrow_kind {
867 BorrowKind::Shared => "",
868 BorrowKind::Mut | BorrowKind::Unique => "mut ",
870 write!(fmt, "&{}{:?}", kind_str, lv)
873 Aggregate(ref kind, ref lvs) => {
874 use self::AggregateKind::*;
876 fn fmt_tuple(fmt: &mut Formatter, lvs: &[Operand]) -> fmt::Result {
877 let mut tuple_fmt = fmt.debug_tuple("");
885 Vec => write!(fmt, "{:?}", lvs),
889 0 => write!(fmt, "()"),
890 1 => write!(fmt, "({:?},)", lvs[0]),
891 _ => fmt_tuple(fmt, lvs),
895 Adt(adt_def, variant, substs) => {
896 let variant_def = &adt_def.variants[variant];
898 ppaux::parameterized(fmt, substs, variant_def.did,
899 ppaux::Ns::Value, &[],
901 tcx.lookup_item_type(variant_def.did).generics
904 match variant_def.kind() {
905 ty::VariantKind::Unit => Ok(()),
906 ty::VariantKind::Tuple => fmt_tuple(fmt, lvs),
907 ty::VariantKind::Struct => {
908 let mut struct_fmt = fmt.debug_struct("");
909 for (field, lv) in variant_def.fields.iter().zip(lvs) {
910 struct_fmt.field(&field.name.as_str(), lv);
917 Closure(def_id, _) => ty::tls::with(|tcx| {
918 if let Some(node_id) = tcx.map.as_local_node_id(def_id) {
919 let name = format!("[closure@{:?}]", tcx.map.span(node_id));
920 let mut struct_fmt = fmt.debug_struct(&name);
922 tcx.with_freevars(node_id, |freevars| {
923 for (freevar, lv) in freevars.iter().zip(lvs) {
924 let var_name = tcx.local_var_name_str(freevar.def.var_id());
925 struct_fmt.field(&var_name, lv);
931 write!(fmt, "[closure]")
940 ///////////////////////////////////////////////////////////////////////////
943 /// Two constants are equal if they are the same constant. Note that
944 /// this does not necessarily mean that they are "==" in Rust -- in
945 /// particular one must be wary of `NaN`!
947 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
948 pub struct Constant<'tcx> {
951 pub literal: Literal<'tcx>,
954 #[derive(Clone, RustcEncodable, RustcDecodable)]
955 pub struct TypedConstVal<'tcx> {
958 pub value: ConstUsize,
961 impl<'tcx> Debug for TypedConstVal<'tcx> {
962 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
963 write!(fmt, "const {}", ConstInt::Usize(self.value))
967 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
968 pub enum Literal<'tcx> {
971 substs: &'tcx Substs<'tcx>,
978 impl<'tcx> Debug for Constant<'tcx> {
979 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
980 write!(fmt, "{:?}", self.literal)
984 impl<'tcx> Debug for Literal<'tcx> {
985 fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
986 use self::Literal::*;
988 Item { def_id, substs } => {
989 ppaux::parameterized(fmt, substs, def_id, ppaux::Ns::Value, &[],
990 |tcx| tcx.lookup_item_type(def_id).generics)
992 Value { ref value } => {
993 write!(fmt, "const ")?;
994 fmt_const_val(fmt, value)
1000 /// Write a `ConstVal` in a way closer to the original source code than the `Debug` output.
1001 fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ConstVal) -> fmt::Result {
1002 use middle::const_val::ConstVal::*;
1004 Float(f) => write!(fmt, "{:?}", f),
1005 Integral(n) => write!(fmt, "{}", n),
1006 Str(ref s) => write!(fmt, "{:?}", s),
1007 ByteStr(ref bytes) => {
1008 let escaped: String = bytes
1010 .flat_map(|&ch| ascii::escape_default(ch).map(|c| c as char))
1012 write!(fmt, "b\"{}\"", escaped)
1014 Bool(b) => write!(fmt, "{:?}", b),
1015 Function(def_id) => write!(fmt, "{}", item_path_str(def_id)),
1016 Struct(node_id) | Tuple(node_id) | Array(node_id, _) | Repeat(node_id, _) =>
1017 write!(fmt, "{}", node_to_string(node_id)),
1018 Char(c) => write!(fmt, "{:?}", c),
1023 fn node_to_string(node_id: ast::NodeId) -> String {
1024 ty::tls::with(|tcx| tcx.map.node_to_user_string(node_id))
1027 fn item_path_str(def_id: DefId) -> String {
1028 ty::tls::with(|tcx| tcx.item_path_str(def_id))