// Copyright 2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! MIR datatypes and passes. See the [rustc guide] for more info. //! //! [rustc guide]: https://rust-lang-nursery.github.io/rustc-guide/mir.html use graphviz::IntoCow; use middle::region; use rustc_data_structures::sync::{Lrc}; use rustc_data_structures::indexed_vec::{IndexVec, Idx}; use rustc_data_structures::control_flow_graph::dominators::{Dominators, dominators}; use rustc_data_structures::control_flow_graph::{GraphPredecessors, GraphSuccessors}; use rustc_data_structures::control_flow_graph::ControlFlowGraph; use rustc_data_structures::small_vec::SmallVec; use rustc_serialize as serialize; use hir::def::CtorKind; use hir::def_id::DefId; use mir::visit::MirVisitable; use mir::interpret::{Value, Scalar, EvalErrorKind}; use ty::subst::{Subst, Substs}; use ty::{self, AdtDef, CanonicalTy, ClosureSubsts, GeneratorSubsts, Region, Ty, TyCtxt}; use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor}; use util::ppaux; use std::slice; use hir::{self, InlineAsm}; use std::borrow::{Cow}; use rustc_data_structures::sync::ReadGuard; use std::fmt::{self, Debug, Formatter, Write}; use std::{iter, mem, option, u32}; use std::ops::{Index, IndexMut}; use std::vec::IntoIter; use syntax::ast::{self, Name}; use syntax::symbol::InternedString; use syntax_pos::{Span, DUMMY_SP}; use rustc_apfloat::ieee::{Single, Double}; use rustc_apfloat::Float; pub use mir::interpret::AssertMessage; mod cache; pub mod tcx; pub mod visit; pub mod traversal; pub mod interpret; pub mod mono; /// Types for locals type LocalDecls<'tcx> = IndexVec>; pub trait HasLocalDecls<'tcx> { fn local_decls(&self) -> &LocalDecls<'tcx>; } impl<'tcx> HasLocalDecls<'tcx> for LocalDecls<'tcx> { fn local_decls(&self) -> &LocalDecls<'tcx> { self } } impl<'tcx> HasLocalDecls<'tcx> for Mir<'tcx> { fn local_decls(&self) -> &LocalDecls<'tcx> { &self.local_decls } } /// Lowered representation of a single function. #[derive(Clone, RustcEncodable, RustcDecodable, Debug)] pub struct Mir<'tcx> { /// List of basic blocks. References to basic block use a newtyped index type `BasicBlock` /// that indexes into this vector. basic_blocks: IndexVec>, /// List of source scopes; these are referenced by statements /// and used for debuginfo. Indexed by a `SourceScope`. pub source_scopes: IndexVec, /// Crate-local information for each source scope, that can't (and /// needn't) be tracked across crates. pub source_scope_local_data: ClearCrossCrate>, /// Rvalues promoted from this function, such as borrows of constants. /// Each of them is the Mir of a constant with the fn's type parameters /// in scope, but a separate set of locals. pub promoted: IndexVec>, /// Yield type of the function, if it is a generator. pub yield_ty: Option>, /// Generator drop glue pub generator_drop: Option>>, /// The layout of a generator. Produced by the state transformation. pub generator_layout: Option>, /// Declarations of locals. /// /// The first local is the return value pointer, followed by `arg_count` /// locals for the function arguments, followed by any user-declared /// variables and temporaries. pub local_decls: LocalDecls<'tcx>, /// Number of arguments this function takes. /// /// Starting at local 1, `arg_count` locals will be provided by the caller /// and can be assumed to be initialized. /// /// If this MIR was built for a constant, this will be 0. pub arg_count: usize, /// Names and capture modes of all the closure upvars, assuming /// the first argument is either the closure or a reference to it. pub upvar_decls: Vec, /// Mark an argument local (which must be a tuple) as getting passed as /// its individual components at the LLVM level. /// /// This is used for the "rust-call" ABI. pub spread_arg: Option, /// A span representing this MIR, for error reporting pub span: Span, /// A cache for various calculations cache: cache::Cache } /// where execution begins pub const START_BLOCK: BasicBlock = BasicBlock(0); impl<'tcx> Mir<'tcx> { pub fn new(basic_blocks: IndexVec>, source_scopes: IndexVec, source_scope_local_data: ClearCrossCrate>, promoted: IndexVec>, yield_ty: Option>, local_decls: IndexVec>, arg_count: usize, upvar_decls: Vec, span: Span) -> Self { // We need `arg_count` locals, and one for the return place assert!(local_decls.len() >= arg_count + 1, "expected at least {} locals, got {}", arg_count + 1, local_decls.len()); Mir { basic_blocks, source_scopes, source_scope_local_data, promoted, yield_ty, generator_drop: None, generator_layout: None, local_decls, arg_count, upvar_decls, spread_arg: None, span, cache: cache::Cache::new() } } #[inline] pub fn basic_blocks(&self) -> &IndexVec> { &self.basic_blocks } #[inline] pub fn basic_blocks_mut(&mut self) -> &mut IndexVec> { self.cache.invalidate(); &mut self.basic_blocks } #[inline] pub fn basic_blocks_and_local_decls_mut(&mut self) -> ( &mut IndexVec>, &mut LocalDecls<'tcx>, ) { self.cache.invalidate(); (&mut self.basic_blocks, &mut self.local_decls) } #[inline] pub fn predecessors(&self) -> ReadGuard>> { self.cache.predecessors(self) } #[inline] pub fn predecessors_for(&self, bb: BasicBlock) -> ReadGuard> { ReadGuard::map(self.predecessors(), |p| &p[bb]) } #[inline] pub fn dominators(&self) -> Dominators { dominators(self) } #[inline] pub fn local_kind(&self, local: Local) -> LocalKind { let index = local.0 as usize; if index == 0 { debug_assert!(self.local_decls[local].mutability == Mutability::Mut, "return place should be mutable"); LocalKind::ReturnPointer } else if index < self.arg_count + 1 { LocalKind::Arg } else if self.local_decls[local].name.is_some() { LocalKind::Var } else { debug_assert!(self.local_decls[local].mutability == Mutability::Mut, "temp should be mutable"); LocalKind::Temp } } /// Returns an iterator over all temporaries. #[inline] pub fn temps_iter<'a>(&'a self) -> impl Iterator + 'a { (self.arg_count+1..self.local_decls.len()).filter_map(move |index| { let local = Local::new(index); if self.local_decls[local].is_user_variable { None } else { Some(local) } }) } /// Returns an iterator over all user-declared locals. #[inline] pub fn vars_iter<'a>(&'a self) -> impl Iterator + 'a { (self.arg_count+1..self.local_decls.len()).filter_map(move |index| { let local = Local::new(index); if self.local_decls[local].is_user_variable { Some(local) } else { None } }) } /// Returns an iterator over all user-declared mutable arguments and locals. #[inline] pub fn mut_vars_and_args_iter<'a>(&'a self) -> impl Iterator + 'a { (1..self.local_decls.len()).filter_map(move |index| { let local = Local::new(index); let decl = &self.local_decls[local]; if (decl.is_user_variable || index < self.arg_count + 1) && decl.mutability == Mutability::Mut { Some(local) } else { None } }) } /// Returns an iterator over all function arguments. #[inline] pub fn args_iter(&self) -> impl Iterator { let arg_count = self.arg_count; (1..arg_count+1).map(Local::new) } /// Returns an iterator over all user-defined variables and compiler-generated temporaries (all /// locals that are neither arguments nor the return place). #[inline] pub fn vars_and_temps_iter(&self) -> impl Iterator { let arg_count = self.arg_count; let local_count = self.local_decls.len(); (arg_count+1..local_count).map(Local::new) } /// Changes a statement to a nop. This is both faster than deleting instructions and avoids /// invalidating statement indices in `Location`s. pub fn make_statement_nop(&mut self, location: Location) { let block = &mut self[location.block]; debug_assert!(location.statement_index < block.statements.len()); block.statements[location.statement_index].make_nop() } /// Returns the source info associated with `location`. pub fn source_info(&self, location: Location) -> &SourceInfo { let block = &self[location.block]; let stmts = &block.statements; let idx = location.statement_index; if idx < stmts.len() { &stmts[idx].source_info } else { assert!(idx == stmts.len()); &block.terminator().source_info } } /// Return the return type, it always return first element from `local_decls` array pub fn return_ty(&self) -> Ty<'tcx> { self.local_decls[RETURN_PLACE].ty } } #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)] pub enum Safety { Safe, /// Unsafe because of a PushUnsafeBlock BuiltinUnsafe, /// Unsafe because of an unsafe fn FnUnsafe, /// Unsafe because of an `unsafe` block ExplicitUnsafe(ast::NodeId) } impl_stable_hash_for!(struct Mir<'tcx> { basic_blocks, source_scopes, source_scope_local_data, promoted, yield_ty, generator_drop, generator_layout, local_decls, arg_count, upvar_decls, spread_arg, span, cache }); impl<'tcx> Index for Mir<'tcx> { type Output = BasicBlockData<'tcx>; #[inline] fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> { &self.basic_blocks()[index] } } impl<'tcx> IndexMut for Mir<'tcx> { #[inline] fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> { &mut self.basic_blocks_mut()[index] } } #[derive(Clone, Debug)] pub enum ClearCrossCrate { Clear, Set(T) } impl serialize::UseSpecializedEncodable for ClearCrossCrate {} impl serialize::UseSpecializedDecodable for ClearCrossCrate {} /// Grouped information about the source code origin of a MIR entity. /// Intended to be inspected by diagnostics and debuginfo. /// Most passes can work with it as a whole, within a single function. #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash)] pub struct SourceInfo { /// Source span for the AST pertaining to this MIR entity. pub span: Span, /// The source scope, keeping track of which bindings can be /// seen by debuginfo, active lint levels, `unsafe {...}`, etc. pub scope: SourceScope } /////////////////////////////////////////////////////////////////////////// // Mutability and borrow kinds #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum Mutability { Mut, Not, } #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum BorrowKind { /// Data must be immutable and is aliasable. Shared, /// Data must be immutable but not aliasable. This kind of borrow /// cannot currently be expressed by the user and is used only in /// implicit closure bindings. It is needed when you the closure /// is borrowing or mutating a mutable referent, e.g.: /// /// let x: &mut isize = ...; /// let y = || *x += 5; /// /// If we were to try to translate this closure into a more explicit /// form, we'd encounter an error with the code as written: /// /// struct Env { x: & &mut isize } /// let x: &mut isize = ...; /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn /// fn fn_ptr(env: &mut Env) { **env.x += 5; } /// /// This is then illegal because you cannot mutate a `&mut` found /// in an aliasable location. To solve, you'd have to translate with /// an `&mut` borrow: /// /// struct Env { x: & &mut isize } /// let x: &mut isize = ...; /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x /// fn fn_ptr(env: &mut Env) { **env.x += 5; } /// /// Now the assignment to `**env.x` is legal, but creating a /// mutable pointer to `x` is not because `x` is not mutable. We /// could fix this by declaring `x` as `let mut x`. This is ok in /// user code, if awkward, but extra weird for closures, since the /// borrow is hidden. /// /// So we introduce a "unique imm" borrow -- the referent is /// immutable, but not aliasable. This solves the problem. For /// simplicity, we don't give users the way to express this /// borrow, it's just used when translating closures. Unique, /// Data is mutable and not aliasable. Mut { /// True if this borrow arose from method-call auto-ref /// (i.e. `adjustment::Adjust::Borrow`) allow_two_phase_borrow: bool } } impl BorrowKind { pub fn allows_two_phase_borrow(&self) -> bool { match *self { BorrowKind::Shared | BorrowKind::Unique => false, BorrowKind::Mut { allow_two_phase_borrow } => allow_two_phase_borrow, } } } /////////////////////////////////////////////////////////////////////////// // Variables and temps newtype_index!(Local { DEBUG_FORMAT = "_{}", const RETURN_PLACE = 0, }); /// Classifies locals into categories. See `Mir::local_kind`. #[derive(PartialEq, Eq, Debug)] pub enum LocalKind { /// User-declared variable binding Var, /// Compiler-introduced temporary Temp, /// Function argument Arg, /// Location of function's return value ReturnPointer, } /// A MIR local. /// /// This can be a binding declared by the user, a temporary inserted by the compiler, a function /// argument, or the return place. #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct LocalDecl<'tcx> { /// `let mut x` vs `let x`. /// /// Temporaries and the return place are always mutable. pub mutability: Mutability, /// True if this corresponds to a user-declared local variable. pub is_user_variable: bool, /// True if this is an internal local /// /// These locals are not based on types in the source code and are only used /// for a few desugarings at the moment. /// /// The generator transformation will sanity check the locals which are live /// across a suspension point against the type components of the generator /// which type checking knows are live across a suspension point. We need to /// flag drop flags to avoid triggering this check as they are introduced /// after typeck. /// /// Unsafety checking will also ignore dereferences of these locals, /// so they can be used for raw pointers only used in a desugaring. /// /// This should be sound because the drop flags are fully algebraic, and /// therefore don't affect the OIBIT or outlives properties of the /// generator. pub internal: bool, /// Type of this local. pub ty: Ty<'tcx>, /// Name of the local, used in debuginfo and pretty-printing. /// /// Note that function arguments can also have this set to `Some(_)` /// to generate better debuginfo. pub name: Option, /// The *syntactic* (i.e. not visibility) source scope the local is defined /// in. If the local was defined in a let-statement, this /// is *within* the let-statement, rather than outside /// of it. /// /// This is needed because the visibility source scope of locals within /// a let-statement is weird. /// /// The reason is that we want the local to be *within* the let-statement /// for lint purposes, but we want the local to be *after* the let-statement /// for names-in-scope purposes. /// /// That's it, if we have a let-statement like the one in this /// function: /// /// ``` /// fn foo(x: &str) { /// #[allow(unused_mut)] /// let mut x: u32 = { // <- one unused mut /// let mut y: u32 = x.parse().unwrap(); /// y + 2 /// }; /// drop(x); /// } /// ``` /// /// Then, from a lint point of view, the declaration of `x: u32` /// (and `y: u32`) are within the `#[allow(unused_mut)]` scope - the /// lint scopes are the same as the AST/HIR nesting. /// /// However, from a name lookup point of view, the scopes look more like /// as if the let-statements were `match` expressions: /// /// ``` /// fn foo(x: &str) { /// match { /// match x.parse().unwrap() { /// y => y + 2 /// } /// } { /// x => drop(x) /// }; /// } /// ``` /// /// We care about the name-lookup scopes for debuginfo - if the /// debuginfo instruction pointer is at the call to `x.parse()`, we /// want `x` to refer to `x: &str`, but if it is at the call to /// `drop(x)`, we want it to refer to `x: u32`. /// /// To allow both uses to work, we need to have more than a single scope /// for a local. We have the `syntactic_source_info.scope` represent the /// "syntactic" lint scope (with a variable being under its let /// block) while the `visibility_source_info.scope` represents the "local variable" /// scope (where the "rest" of a block is under all prior let-statements). /// /// The end result looks like this: /// /// ```text /// ROOT SCOPE /// │{ argument x: &str } /// │ /// │ │{ #[allow(unused_mut] } // this is actually split into 2 scopes /// │ │ // in practice because I'm lazy. /// │ │ /// │ │← x.syntactic_source_info.scope /// │ │← `x.parse().unwrap()` /// │ │ /// │ │ │← y.syntactic_source_info.scope /// │ │ /// │ │ │{ let y: u32 } /// │ │ │ /// │ │ │← y.visibility_source_info.scope /// │ │ │← `y + 2` /// │ /// │ │{ let x: u32 } /// │ │← x.visibility_source_info.scope /// │ │← `drop(x)` // this accesses `x: u32` /// ``` pub syntactic_source_info: SourceInfo, /// Source info of the local. The `SourceScope` is the *visibility* one, /// not the the *syntactic* one (see `syntactic_source_info` for more details). pub visibility_source_info: SourceInfo, } impl<'tcx> LocalDecl<'tcx> { /// Create a new `LocalDecl` for a temporary. #[inline] pub fn new_temp(ty: Ty<'tcx>, span: Span) -> Self { LocalDecl { mutability: Mutability::Mut, ty, name: None, syntactic_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, visibility_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, internal: false, is_user_variable: false } } /// Create a new `LocalDecl` for a internal temporary. #[inline] pub fn new_internal(ty: Ty<'tcx>, span: Span) -> Self { LocalDecl { mutability: Mutability::Mut, ty, name: None, syntactic_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, visibility_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, internal: true, is_user_variable: false } } /// Builds a `LocalDecl` for the return place. /// /// This must be inserted into the `local_decls` list as the first local. #[inline] pub fn new_return_place(return_ty: Ty, span: Span) -> LocalDecl { LocalDecl { mutability: Mutability::Mut, ty: return_ty, syntactic_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, visibility_source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, internal: false, name: None, // FIXME maybe we do want some name here? is_user_variable: false } } } /// A closure capture, with its name and mode. #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct UpvarDecl { pub debug_name: Name, /// If true, the capture is behind a reference. pub by_ref: bool, pub mutability: Mutability, } /////////////////////////////////////////////////////////////////////////// // BasicBlock newtype_index!(BasicBlock { DEBUG_FORMAT = "bb{}" }); impl BasicBlock { pub fn start_location(self) -> Location { Location { block: self, statement_index: 0, } } } /////////////////////////////////////////////////////////////////////////// // BasicBlockData and Terminator #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct BasicBlockData<'tcx> { /// List of statements in this block. pub statements: Vec>, /// Terminator for this block. /// /// NB. This should generally ONLY be `None` during construction. /// Therefore, you should generally access it via the /// `terminator()` or `terminator_mut()` methods. The only /// exception is that certain passes, such as `simplify_cfg`, swap /// out the terminator temporarily with `None` while they continue /// to recurse over the set of basic blocks. pub terminator: Option>, /// If true, this block lies on an unwind path. This is used /// during codegen where distinct kinds of basic blocks may be /// generated (particularly for MSVC cleanup). Unwind blocks must /// only branch to other unwind blocks. pub is_cleanup: bool, } #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct Terminator<'tcx> { pub source_info: SourceInfo, pub kind: TerminatorKind<'tcx> } #[derive(Clone, RustcEncodable, RustcDecodable)] pub enum TerminatorKind<'tcx> { /// block should have one successor in the graph; we jump there Goto { target: BasicBlock, }, /// operand evaluates to an integer; jump depending on its value /// to one of the targets, and otherwise fallback to `otherwise` SwitchInt { /// discriminant value being tested discr: Operand<'tcx>, /// type of value being tested switch_ty: Ty<'tcx>, /// Possible values. The locations to branch to in each case /// are found in the corresponding indices from the `targets` vector. values: Cow<'tcx, [u128]>, /// Possible branch sites. The last element of this vector is used /// for the otherwise branch, so targets.len() == values.len() + 1 /// should hold. // This invariant is quite non-obvious and also could be improved. // One way to make this invariant is to have something like this instead: // // branches: Vec<(ConstInt, BasicBlock)>, // otherwise: Option // exhaustive if None // // However we’ve decided to keep this as-is until we figure a case // where some other approach seems to be strictly better than other. targets: Vec, }, /// Indicates that the landing pad is finished and unwinding should /// continue. Emitted by build::scope::diverge_cleanup. Resume, /// Indicates that the landing pad is finished and that the process /// should abort. Used to prevent unwinding for foreign items. Abort, /// Indicates a normal return. The return place should have /// been filled in by now. This should occur at most once. Return, /// Indicates a terminator that can never be reached. Unreachable, /// Drop the Place Drop { location: Place<'tcx>, target: BasicBlock, unwind: Option }, /// Drop the Place and assign the new value over it. This ensures /// that the assignment to `P` occurs *even if* the destructor for /// place unwinds. Its semantics are best explained by by the /// elaboration: /// /// ``` /// BB0 { /// DropAndReplace(P <- V, goto BB1, unwind BB2) /// } /// ``` /// /// becomes /// /// ``` /// BB0 { /// Drop(P, goto BB1, unwind BB2) /// } /// BB1 { /// // P is now unitialized /// P <- V /// } /// BB2 { /// // P is now unitialized -- its dtor panicked /// P <- V /// } /// ``` DropAndReplace { location: Place<'tcx>, value: Operand<'tcx>, target: BasicBlock, unwind: Option, }, /// Block ends with a call of a converging function Call { /// The function that’s being called func: Operand<'tcx>, /// Arguments the function is called with. /// These are owned by the callee, which is free to modify them. /// This allows the memory occupied by "by-value" arguments to be /// reused across function calls without duplicating the contents. args: Vec>, /// Destination for the return value. If some, the call is converging. destination: Option<(Place<'tcx>, BasicBlock)>, /// Cleanups to be done if the call unwinds. cleanup: Option }, /// Jump to the target if the condition has the expected value, /// otherwise panic with a message and a cleanup target. Assert { cond: Operand<'tcx>, expected: bool, msg: AssertMessage<'tcx>, target: BasicBlock, cleanup: Option }, /// A suspend point Yield { /// The value to return value: Operand<'tcx>, /// Where to resume to resume: BasicBlock, /// Cleanup to be done if the generator is dropped at this suspend point drop: Option, }, /// Indicates the end of the dropping of a generator GeneratorDrop, /// A block where control flow only ever takes one real path, but borrowck /// needs to be more conservative. FalseEdges { /// The target normal control flow will take real_target: BasicBlock, /// The list of blocks control flow could conceptually take, but won't /// in practice imaginary_targets: Vec, }, /// A terminator for blocks that only take one path in reality, but where we /// reserve the right to unwind in borrowck, even if it won't happen in practice. /// This can arise in infinite loops with no function calls for example. FalseUnwind { /// The target normal control flow will take real_target: BasicBlock, /// The imaginary cleanup block link. This particular path will never be taken /// in practice, but in order to avoid fragility we want to always /// consider it in borrowck. We don't want to accept programs which /// pass borrowck only when panic=abort or some assertions are disabled /// due to release vs. debug mode builds. This needs to be an Option because /// of the remove_noop_landing_pads and no_landing_pads passes unwind: Option, }, } pub type Successors<'a> = iter::Chain, slice::Iter<'a, BasicBlock>>; pub type SuccessorsMut<'a> = iter::Chain, slice::IterMut<'a, BasicBlock>>; impl<'tcx> Terminator<'tcx> { pub fn successors(&self) -> Successors { self.kind.successors() } pub fn successors_mut(&mut self) -> SuccessorsMut { self.kind.successors_mut() } pub fn unwind_mut(&mut self) -> Option<&mut Option> { self.kind.unwind_mut() } } impl<'tcx> TerminatorKind<'tcx> { pub fn if_<'a, 'gcx>(tcx: TyCtxt<'a, 'gcx, 'tcx>, cond: Operand<'tcx>, t: BasicBlock, f: BasicBlock) -> TerminatorKind<'tcx> { static BOOL_SWITCH_FALSE: &'static [u128] = &[0]; TerminatorKind::SwitchInt { discr: cond, switch_ty: tcx.types.bool, values: From::from(BOOL_SWITCH_FALSE), targets: vec![f, t], } } pub fn successors(&self) -> Successors { use self::TerminatorKind::*; match *self { Resume | Abort | GeneratorDrop | Return | Unreachable | Call { destination: None, cleanup: None, .. } => { None.into_iter().chain(&[]) } Goto { target: ref t } | Call { destination: None, cleanup: Some(ref t), .. } | Call { destination: Some((_, ref t)), cleanup: None, .. } | Yield { resume: ref t, drop: None, .. } | DropAndReplace { target: ref t, unwind: None, .. } | Drop { target: ref t, unwind: None, .. } | Assert { target: ref t, cleanup: None, .. } | FalseUnwind { real_target: ref t, unwind: None } => { Some(t).into_iter().chain(&[]) } Call { destination: Some((_, ref t)), cleanup: Some(ref u), .. } | Yield { resume: ref t, drop: Some(ref u), .. } | DropAndReplace { target: ref t, unwind: Some(ref u), .. } | Drop { target: ref t, unwind: Some(ref u), .. } | Assert { target: ref t, cleanup: Some(ref u), .. } | FalseUnwind { real_target: ref t, unwind: Some(ref u) } => { Some(t).into_iter().chain(slice::from_ref(u)) } SwitchInt { ref targets, .. } => { None.into_iter().chain(&targets[..]) } FalseEdges { ref real_target, ref imaginary_targets } => { Some(real_target).into_iter().chain(&imaginary_targets[..]) } } } pub fn successors_mut(&mut self) -> SuccessorsMut { use self::TerminatorKind::*; match *self { Resume | Abort | GeneratorDrop | Return | Unreachable | Call { destination: None, cleanup: None, .. } => { None.into_iter().chain(&mut []) } Goto { target: ref mut t } | Call { destination: None, cleanup: Some(ref mut t), .. } | Call { destination: Some((_, ref mut t)), cleanup: None, .. } | Yield { resume: ref mut t, drop: None, .. } | DropAndReplace { target: ref mut t, unwind: None, .. } | Drop { target: ref mut t, unwind: None, .. } | Assert { target: ref mut t, cleanup: None, .. } | FalseUnwind { real_target: ref mut t, unwind: None } => { Some(t).into_iter().chain(&mut []) } Call { destination: Some((_, ref mut t)), cleanup: Some(ref mut u), .. } | Yield { resume: ref mut t, drop: Some(ref mut u), .. } | DropAndReplace { target: ref mut t, unwind: Some(ref mut u), .. } | Drop { target: ref mut t, unwind: Some(ref mut u), .. } | Assert { target: ref mut t, cleanup: Some(ref mut u), .. } | FalseUnwind { real_target: ref mut t, unwind: Some(ref mut u) } => { Some(t).into_iter().chain(slice::from_mut(u)) } SwitchInt { ref mut targets, .. } => { None.into_iter().chain(&mut targets[..]) } FalseEdges { ref mut real_target, ref mut imaginary_targets } => { Some(real_target).into_iter().chain(&mut imaginary_targets[..]) } } } pub fn unwind_mut(&mut self) -> Option<&mut Option> { match *self { TerminatorKind::Goto { .. } | TerminatorKind::Resume | TerminatorKind::Abort | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::GeneratorDrop | TerminatorKind::Yield { .. } | TerminatorKind::SwitchInt { .. } | TerminatorKind::FalseEdges { .. } => { None }, TerminatorKind::Call { cleanup: ref mut unwind, .. } | TerminatorKind::Assert { cleanup: ref mut unwind, .. } | TerminatorKind::DropAndReplace { ref mut unwind, .. } | TerminatorKind::Drop { ref mut unwind, .. } | TerminatorKind::FalseUnwind { ref mut unwind, .. } => { Some(unwind) } } } } impl<'tcx> BasicBlockData<'tcx> { pub fn new(terminator: Option>) -> BasicBlockData<'tcx> { BasicBlockData { statements: vec![], terminator, is_cleanup: false, } } /// Accessor for terminator. /// /// Terminator may not be None after construction of the basic block is complete. This accessor /// provides a convenience way to reach the terminator. pub fn terminator(&self) -> &Terminator<'tcx> { self.terminator.as_ref().expect("invalid terminator state") } pub fn terminator_mut(&mut self) -> &mut Terminator<'tcx> { self.terminator.as_mut().expect("invalid terminator state") } pub fn retain_statements(&mut self, mut f: F) where F: FnMut(&mut Statement) -> bool { for s in &mut self.statements { if !f(s) { s.make_nop(); } } } pub fn expand_statements(&mut self, mut f: F) where F: FnMut(&mut Statement<'tcx>) -> Option, I: iter::TrustedLen> { // Gather all the iterators we'll need to splice in, and their positions. let mut splices: Vec<(usize, I)> = vec![]; let mut extra_stmts = 0; for (i, s) in self.statements.iter_mut().enumerate() { if let Some(mut new_stmts) = f(s) { if let Some(first) = new_stmts.next() { // We can already store the first new statement. *s = first; // Save the other statements for optimized splicing. let remaining = new_stmts.size_hint().0; if remaining > 0 { splices.push((i + 1 + extra_stmts, new_stmts)); extra_stmts += remaining; } } else { s.make_nop(); } } } // Splice in the new statements, from the end of the block. // FIXME(eddyb) This could be more efficient with a "gap buffer" // where a range of elements ("gap") is left uninitialized, with // splicing adding new elements to the end of that gap and moving // existing elements from before the gap to the end of the gap. // For now, this is safe code, emulating a gap but initializing it. let mut gap = self.statements.len()..self.statements.len()+extra_stmts; self.statements.resize(gap.end, Statement { source_info: SourceInfo { span: DUMMY_SP, scope: OUTERMOST_SOURCE_SCOPE }, kind: StatementKind::Nop }); for (splice_start, new_stmts) in splices.into_iter().rev() { let splice_end = splice_start + new_stmts.size_hint().0; while gap.end > splice_end { gap.start -= 1; gap.end -= 1; self.statements.swap(gap.start, gap.end); } self.statements.splice(splice_start..splice_end, new_stmts); gap.end = splice_start; } } pub fn visitable(&self, index: usize) -> &dyn MirVisitable<'tcx> { if index < self.statements.len() { &self.statements[index] } else { &self.terminator } } } impl<'tcx> Debug for TerminatorKind<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { self.fmt_head(fmt)?; let successor_count = self.successors().count(); let labels = self.fmt_successor_labels(); assert_eq!(successor_count, labels.len()); match successor_count { 0 => Ok(()), 1 => write!(fmt, " -> {:?}", self.successors().nth(0).unwrap()), _ => { write!(fmt, " -> [")?; for (i, target) in self.successors().enumerate() { if i > 0 { write!(fmt, ", ")?; } write!(fmt, "{}: {:?}", labels[i], target)?; } write!(fmt, "]") } } } } impl<'tcx> TerminatorKind<'tcx> { /// Write the "head" part of the terminator; that is, its name and the data it uses to pick the /// successor basic block, if any. The only information not included is the list of possible /// successors, which may be rendered differently between the text and the graphviz format. pub fn fmt_head(&self, fmt: &mut W) -> fmt::Result { use self::TerminatorKind::*; match *self { Goto { .. } => write!(fmt, "goto"), SwitchInt { discr: ref place, .. } => write!(fmt, "switchInt({:?})", place), Return => write!(fmt, "return"), GeneratorDrop => write!(fmt, "generator_drop"), Resume => write!(fmt, "resume"), Abort => write!(fmt, "abort"), Yield { ref value, .. } => write!(fmt, "_1 = suspend({:?})", value), Unreachable => write!(fmt, "unreachable"), Drop { ref location, .. } => write!(fmt, "drop({:?})", location), DropAndReplace { ref location, ref value, .. } => write!(fmt, "replace({:?} <- {:?})", location, value), Call { ref func, ref args, ref destination, .. } => { if let Some((ref destination, _)) = *destination { write!(fmt, "{:?} = ", destination)?; } write!(fmt, "{:?}(", func)?; for (index, arg) in args.iter().enumerate() { if index > 0 { write!(fmt, ", ")?; } write!(fmt, "{:?}", arg)?; } write!(fmt, ")") } Assert { ref cond, expected, ref msg, .. } => { write!(fmt, "assert(")?; if !expected { write!(fmt, "!")?; } write!(fmt, "{:?}, \"{:?}\")", cond, msg) }, FalseEdges { .. } => write!(fmt, "falseEdges"), FalseUnwind { .. } => write!(fmt, "falseUnwind"), } } /// Return the list of labels for the edges to the successor basic blocks. pub fn fmt_successor_labels(&self) -> Vec> { use self::TerminatorKind::*; match *self { Return | Resume | Abort | Unreachable | GeneratorDrop => vec![], Goto { .. } => vec!["".into()], SwitchInt { ref values, switch_ty, .. } => { let size = ty::tls::with(|tcx| { let param_env = ty::ParamEnv::empty(); let switch_ty = tcx.lift_to_global(&switch_ty).unwrap(); tcx.layout_of(param_env.and(switch_ty)).unwrap().size }); values.iter() .map(|&u| { let mut s = String::new(); print_miri_value( Value::Scalar(Scalar::Bits { bits: u, defined: size.bits() as u8 }), switch_ty, &mut s, ).unwrap(); s.into() }) .chain(iter::once(String::from("otherwise").into())) .collect() } Call { destination: Some(_), cleanup: Some(_), .. } => vec!["return".into_cow(), "unwind".into_cow()], Call { destination: Some(_), cleanup: None, .. } => vec!["return".into_cow()], Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into_cow()], Call { destination: None, cleanup: None, .. } => vec![], Yield { drop: Some(_), .. } => vec!["resume".into_cow(), "drop".into_cow()], Yield { drop: None, .. } => vec!["resume".into_cow()], DropAndReplace { unwind: None, .. } | Drop { unwind: None, .. } => vec!["return".into_cow()], DropAndReplace { unwind: Some(_), .. } | Drop { unwind: Some(_), .. } => { vec!["return".into_cow(), "unwind".into_cow()] } Assert { cleanup: None, .. } => vec!["".into()], Assert { .. } => vec!["success".into_cow(), "unwind".into_cow()], FalseEdges { ref imaginary_targets, .. } => { let mut l = vec!["real".into()]; l.resize(imaginary_targets.len() + 1, "imaginary".into()); l } FalseUnwind { unwind: Some(_), .. } => vec!["real".into(), "cleanup".into()], FalseUnwind { unwind: None, .. } => vec!["real".into()], } } } /////////////////////////////////////////////////////////////////////////// // Statements #[derive(Clone, RustcEncodable, RustcDecodable)] pub struct Statement<'tcx> { pub source_info: SourceInfo, pub kind: StatementKind<'tcx>, } impl<'tcx> Statement<'tcx> { /// Changes a statement to a nop. This is both faster than deleting instructions and avoids /// invalidating statement indices in `Location`s. pub fn make_nop(&mut self) { self.kind = StatementKind::Nop } /// Changes a statement to a nop and returns the original statement. pub fn replace_nop(&mut self) -> Self { Statement { source_info: self.source_info, kind: mem::replace(&mut self.kind, StatementKind::Nop) } } } #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub enum StatementKind<'tcx> { /// Write the RHS Rvalue to the LHS Place. Assign(Place<'tcx>, Rvalue<'tcx>), /// This represents all the reading that a pattern match may do /// (e.g. inspecting constants and discriminant values). ReadForMatch(Place<'tcx>), /// Write the discriminant for a variant to the enum Place. SetDiscriminant { place: Place<'tcx>, variant_index: usize }, /// Start a live range for the storage of the local. StorageLive(Local), /// End the current live range for the storage of the local. StorageDead(Local), /// Execute a piece of inline Assembly. InlineAsm { asm: Box, outputs: Vec>, inputs: Vec> }, /// Assert the given places to be valid inhabitants of their type. These statements are /// currently only interpreted by miri and only generated when "-Z mir-emit-validate" is passed. /// See for more details. Validate(ValidationOp, Vec>>), /// Mark one terminating point of a region scope (i.e. static region). /// (The starting point(s) arise implicitly from borrows.) EndRegion(region::Scope), /// Encodes a user's type assertion. These need to be preserved intact so that NLL can respect /// them. For example: /// /// let (a, b): (T, U) = y; /// /// Here we would insert a `UserAssertTy<(T, U)>(y)` instruction to check that the type of `y` /// is the right thing. /// /// `CanonicalTy` is used to capture "inference variables" from the user's types. For example: /// /// let x: Vec<_> = ...; /// let y: &u32 = ...; /// /// would result in `Vec` and `&'?0 u32` respectively (where `?0` is a canonicalized /// variable). UserAssertTy(CanonicalTy<'tcx>, Local), /// No-op. Useful for deleting instructions without affecting statement indices. Nop, } /// The `ValidationOp` describes what happens with each of the operands of a /// `Validate` statement. #[derive(Copy, Clone, RustcEncodable, RustcDecodable, PartialEq, Eq)] pub enum ValidationOp { /// Recursively traverse the place following the type and validate that all type /// invariants are maintained. Furthermore, acquire exclusive/read-only access to the /// memory reachable from the place. Acquire, /// Recursive traverse the *mutable* part of the type and relinquish all exclusive /// access. Release, /// Recursive traverse the *mutable* part of the type and relinquish all exclusive /// access *until* the given region ends. Then, access will be recovered. Suspend(region::Scope), } impl Debug for ValidationOp { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::ValidationOp::*; match *self { Acquire => write!(fmt, "Acquire"), Release => write!(fmt, "Release"), // (reuse lifetime rendering policy from ppaux.) Suspend(ref ce) => write!(fmt, "Suspend({})", ty::ReScope(*ce)), } } } // This is generic so that it can be reused by miri #[derive(Clone, RustcEncodable, RustcDecodable)] pub struct ValidationOperand<'tcx, T> { pub place: T, pub ty: Ty<'tcx>, pub re: Option, pub mutbl: hir::Mutability, } impl<'tcx, T: Debug> Debug for ValidationOperand<'tcx, T> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { write!(fmt, "{:?}: {:?}", self.place, self.ty)?; if let Some(ce) = self.re { // (reuse lifetime rendering policy from ppaux.) write!(fmt, "/{}", ty::ReScope(ce))?; } if let hir::MutImmutable = self.mutbl { write!(fmt, " (imm)")?; } Ok(()) } } impl<'tcx> Debug for Statement<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::StatementKind::*; match self.kind { Assign(ref place, ref rv) => write!(fmt, "{:?} = {:?}", place, rv), ReadForMatch(ref place) => write!(fmt, "ReadForMatch({:?})", place), // (reuse lifetime rendering policy from ppaux.) EndRegion(ref ce) => write!(fmt, "EndRegion({})", ty::ReScope(*ce)), Validate(ref op, ref places) => write!(fmt, "Validate({:?}, {:?})", op, places), StorageLive(ref place) => write!(fmt, "StorageLive({:?})", place), StorageDead(ref place) => write!(fmt, "StorageDead({:?})", place), SetDiscriminant { ref place, variant_index } => { write!(fmt, "discriminant({:?}) = {:?}", place, variant_index) }, InlineAsm { ref asm, ref outputs, ref inputs } => { write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs) }, UserAssertTy(ref c_ty, ref local) => write!(fmt, "UserAssertTy({:?}, {:?})", c_ty, local), Nop => write!(fmt, "nop"), } } } /////////////////////////////////////////////////////////////////////////// // Places /// A path to a value; something that can be evaluated without /// changing or disturbing program state. #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub enum Place<'tcx> { /// local variable Local(Local), /// static or static mut variable Static(Box>), /// projection out of a place (access a field, deref a pointer, etc) Projection(Box>), } /// The def-id of a static, along with its normalized type (which is /// stored to avoid requiring normalization when reading MIR). #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub struct Static<'tcx> { pub def_id: DefId, pub ty: Ty<'tcx>, } impl_stable_hash_for!(struct Static<'tcx> { def_id, ty }); /// The `Projection` data structure defines things of the form `B.x` /// or `*B` or `B[index]`. Note that it is parameterized because it is /// shared between `Constant` and `Place`. See the aliases /// `PlaceProjection` etc below. #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub struct Projection<'tcx, B, V, T> { pub base: B, pub elem: ProjectionElem<'tcx, V, T>, } #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub enum ProjectionElem<'tcx, V, T> { Deref, Field(Field, T), Index(V), /// These indices are generated by slice patterns. Easiest to explain /// by example: /// /// ``` /// [X, _, .._, _, _] => { offset: 0, min_length: 4, from_end: false }, /// [_, X, .._, _, _] => { offset: 1, min_length: 4, from_end: false }, /// [_, _, .._, X, _] => { offset: 2, min_length: 4, from_end: true }, /// [_, _, .._, _, X] => { offset: 1, min_length: 4, from_end: true }, /// ``` ConstantIndex { /// index or -index (in Python terms), depending on from_end offset: u32, /// thing being indexed must be at least this long min_length: u32, /// counting backwards from end? from_end: bool, }, /// These indices are generated by slice patterns. /// /// slice[from:-to] in Python terms. Subslice { from: u32, to: u32, }, /// "Downcast" to a variant of an ADT. Currently, we only introduce /// this for ADTs with more than one variant. It may be better to /// just introduce it always, or always for enums. Downcast(&'tcx AdtDef, usize), } /// Alias for projections as they appear in places, where the base is a place /// and the index is a local. pub type PlaceProjection<'tcx> = Projection<'tcx, Place<'tcx>, Local, Ty<'tcx>>; /// Alias for projections as they appear in places, where the base is a place /// and the index is a local. pub type PlaceElem<'tcx> = ProjectionElem<'tcx, Local, Ty<'tcx>>; newtype_index!(Field { DEBUG_FORMAT = "field[{}]" }); impl<'tcx> Place<'tcx> { pub fn field(self, f: Field, ty: Ty<'tcx>) -> Place<'tcx> { self.elem(ProjectionElem::Field(f, ty)) } pub fn deref(self) -> Place<'tcx> { self.elem(ProjectionElem::Deref) } pub fn downcast(self, adt_def: &'tcx AdtDef, variant_index: usize) -> Place<'tcx> { self.elem(ProjectionElem::Downcast(adt_def, variant_index)) } pub fn index(self, index: Local) -> Place<'tcx> { self.elem(ProjectionElem::Index(index)) } pub fn elem(self, elem: PlaceElem<'tcx>) -> Place<'tcx> { Place::Projection(Box::new(PlaceProjection { base: self, elem, })) } } impl<'tcx> Debug for Place<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::Place::*; match *self { Local(id) => write!(fmt, "{:?}", id), Static(box self::Static { def_id, ty }) => write!(fmt, "({}: {:?})", ty::tls::with(|tcx| tcx.item_path_str(def_id)), ty), Projection(ref data) => match data.elem { ProjectionElem::Downcast(ref adt_def, index) => write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name), ProjectionElem::Deref => write!(fmt, "(*{:?})", data.base), ProjectionElem::Field(field, ty) => write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty), ProjectionElem::Index(ref index) => write!(fmt, "{:?}[{:?}]", data.base, index), ProjectionElem::ConstantIndex { offset, min_length, from_end: false } => write!(fmt, "{:?}[{:?} of {:?}]", data.base, offset, min_length), ProjectionElem::ConstantIndex { offset, min_length, from_end: true } => write!(fmt, "{:?}[-{:?} of {:?}]", data.base, offset, min_length), ProjectionElem::Subslice { from, to } if to == 0 => write!(fmt, "{:?}[{:?}:]", data.base, from), ProjectionElem::Subslice { from, to } if from == 0 => write!(fmt, "{:?}[:-{:?}]", data.base, to), ProjectionElem::Subslice { from, to } => write!(fmt, "{:?}[{:?}:-{:?}]", data.base, from, to), }, } } } /////////////////////////////////////////////////////////////////////////// // Scopes newtype_index!(SourceScope { DEBUG_FORMAT = "scope[{}]", const OUTERMOST_SOURCE_SCOPE = 0, }); #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct SourceScopeData { pub span: Span, pub parent_scope: Option, } #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct SourceScopeLocalData { /// A NodeId with lint levels equivalent to this scope's lint levels. pub lint_root: ast::NodeId, /// The unsafe block that contains this node. pub safety: Safety, } /////////////////////////////////////////////////////////////////////////// // Operands /// These are values that can appear inside an rvalue (or an index /// place). They are intentionally limited to prevent rvalues from /// being nested in one another. #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)] pub enum Operand<'tcx> { /// Copy: The value must be available for use afterwards. /// /// This implies that the type of the place must be `Copy`; this is true /// by construction during build, but also checked by the MIR type checker. Copy(Place<'tcx>), /// Move: The value (including old borrows of it) will not be used again. /// /// Safe for values of all types (modulo future developments towards `?Move`). /// Correct usage patterns are enforced by the borrow checker for safe code. /// `Copy` may be converted to `Move` to enable "last-use" optimizations. Move(Place<'tcx>), Constant(Box>), } impl<'tcx> Debug for Operand<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::Operand::*; match *self { Constant(ref a) => write!(fmt, "{:?}", a), Copy(ref place) => write!(fmt, "{:?}", place), Move(ref place) => write!(fmt, "move {:?}", place), } } } impl<'tcx> Operand<'tcx> { pub fn function_handle<'a>( tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId, substs: &'tcx Substs<'tcx>, span: Span, ) -> Self { let ty = tcx.type_of(def_id).subst(tcx, substs); Operand::Constant(box Constant { span, ty, literal: Literal::Value { value: ty::Const::zero_sized(tcx, ty), }, }) } pub fn to_copy(&self) -> Self { match *self { Operand::Copy(_) | Operand::Constant(_) => self.clone(), Operand::Move(ref place) => Operand::Copy(place.clone()) } } } /////////////////////////////////////////////////////////////////////////// /// Rvalues #[derive(Clone, RustcEncodable, RustcDecodable)] pub enum Rvalue<'tcx> { /// x (either a move or copy, depending on type of x) Use(Operand<'tcx>), /// [x; 32] Repeat(Operand<'tcx>, u64), /// &x or &mut x Ref(Region<'tcx>, BorrowKind, Place<'tcx>), /// length of a [X] or [X;n] value Len(Place<'tcx>), Cast(CastKind, Operand<'tcx>, Ty<'tcx>), BinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>), CheckedBinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>), NullaryOp(NullOp, Ty<'tcx>), UnaryOp(UnOp, Operand<'tcx>), /// Read the discriminant of an ADT. /// /// Undefined (i.e. no effort is made to make it defined, but there’s no reason why it cannot /// be defined to return, say, a 0) if ADT is not an enum. Discriminant(Place<'tcx>), /// Create an aggregate value, like a tuple or struct. This is /// only needed because we want to distinguish `dest = Foo { x: /// ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case /// that `Foo` has a destructor. These rvalues can be optimized /// away after type-checking and before lowering. Aggregate(Box>, Vec>), } #[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum CastKind { Misc, /// Convert unique, zero-sized type for a fn to fn() ReifyFnPointer, /// Convert non capturing closure to fn() ClosureFnPointer, /// Convert safe fn() to unsafe fn() UnsafeFnPointer, /// "Unsize" -- convert a thin-or-fat pointer to a fat pointer. /// codegen must figure out the details once full monomorphization /// is known. For example, this could be used to cast from a /// `&[i32;N]` to a `&[i32]`, or a `Box` to a `Box` /// (presuming `T: Trait`). Unsize, } #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum AggregateKind<'tcx> { /// The type is of the element Array(Ty<'tcx>), Tuple, /// The second field is the variant index. It's equal to 0 for struct /// and union expressions. The fourth field is /// active field number and is present only for union expressions /// -- e.g. for a union expression `SomeUnion { c: .. }`, the /// active field index would identity the field `c` Adt(&'tcx AdtDef, usize, &'tcx Substs<'tcx>, Option), Closure(DefId, ClosureSubsts<'tcx>), Generator(DefId, GeneratorSubsts<'tcx>, hir::GeneratorMovability), } #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum BinOp { /// The `+` operator (addition) Add, /// The `-` operator (subtraction) Sub, /// The `*` operator (multiplication) Mul, /// The `/` operator (division) Div, /// The `%` operator (modulus) Rem, /// The `^` operator (bitwise xor) BitXor, /// The `&` operator (bitwise and) BitAnd, /// The `|` operator (bitwise or) BitOr, /// The `<<` operator (shift left) Shl, /// The `>>` operator (shift right) Shr, /// The `==` operator (equality) Eq, /// The `<` operator (less than) Lt, /// The `<=` operator (less than or equal to) Le, /// The `!=` operator (not equal to) Ne, /// The `>=` operator (greater than or equal to) Ge, /// The `>` operator (greater than) Gt, /// The `ptr.offset` operator Offset, } impl BinOp { pub fn is_checkable(self) -> bool { use self::BinOp::*; match self { Add | Sub | Mul | Shl | Shr => true, _ => false } } } #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum NullOp { /// Return the size of a value of that type SizeOf, /// Create a new uninitialized box for a value of that type Box, } #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)] pub enum UnOp { /// The `!` operator for logical inversion Not, /// The `-` operator for negation Neg, } impl<'tcx> Debug for Rvalue<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::Rvalue::*; match *self { Use(ref place) => write!(fmt, "{:?}", place), Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b), Len(ref a) => write!(fmt, "Len({:?})", a), Cast(ref kind, ref place, ref ty) => { write!(fmt, "{:?} as {:?} ({:?})", place, ty, kind) } BinaryOp(ref op, ref a, ref b) => write!(fmt, "{:?}({:?}, {:?})", op, a, b), CheckedBinaryOp(ref op, ref a, ref b) => { write!(fmt, "Checked{:?}({:?}, {:?})", op, a, b) } UnaryOp(ref op, ref a) => write!(fmt, "{:?}({:?})", op, a), Discriminant(ref place) => write!(fmt, "discriminant({:?})", place), NullaryOp(ref op, ref t) => write!(fmt, "{:?}({:?})", op, t), Ref(region, borrow_kind, ref place) => { let kind_str = match borrow_kind { BorrowKind::Shared => "", BorrowKind::Mut { .. } | BorrowKind::Unique => "mut ", }; // When printing regions, add trailing space if necessary. let region = if ppaux::verbose() || ppaux::identify_regions() { let mut region = format!("{}", region); if region.len() > 0 { region.push(' '); } region } else { // Do not even print 'static "".to_owned() }; write!(fmt, "&{}{}{:?}", region, kind_str, place) } Aggregate(ref kind, ref places) => { fn fmt_tuple(fmt: &mut Formatter, places: &[Operand]) -> fmt::Result { let mut tuple_fmt = fmt.debug_tuple(""); for place in places { tuple_fmt.field(place); } tuple_fmt.finish() } match **kind { AggregateKind::Array(_) => write!(fmt, "{:?}", places), AggregateKind::Tuple => { match places.len() { 0 => write!(fmt, "()"), 1 => write!(fmt, "({:?},)", places[0]), _ => fmt_tuple(fmt, places), } } AggregateKind::Adt(adt_def, variant, substs, _) => { let variant_def = &adt_def.variants[variant]; ppaux::parameterized(fmt, substs, variant_def.did, &[])?; match variant_def.ctor_kind { CtorKind::Const => Ok(()), CtorKind::Fn => fmt_tuple(fmt, places), CtorKind::Fictive => { let mut struct_fmt = fmt.debug_struct(""); for (field, place) in variant_def.fields.iter().zip(places) { struct_fmt.field(&field.ident.as_str(), place); } struct_fmt.finish() } } } AggregateKind::Closure(def_id, _) => ty::tls::with(|tcx| { if let Some(node_id) = tcx.hir.as_local_node_id(def_id) { let name = if tcx.sess.opts.debugging_opts.span_free_formats { format!("[closure@{:?}]", node_id) } else { format!("[closure@{:?}]", tcx.hir.span(node_id)) }; let mut struct_fmt = fmt.debug_struct(&name); tcx.with_freevars(node_id, |freevars| { for (freevar, place) in freevars.iter().zip(places) { let var_name = tcx.hir.name(freevar.var_id()); struct_fmt.field(&var_name.as_str(), place); } }); struct_fmt.finish() } else { write!(fmt, "[closure]") } }), AggregateKind::Generator(def_id, _, _) => ty::tls::with(|tcx| { if let Some(node_id) = tcx.hir.as_local_node_id(def_id) { let name = format!("[generator@{:?}]", tcx.hir.span(node_id)); let mut struct_fmt = fmt.debug_struct(&name); tcx.with_freevars(node_id, |freevars| { for (freevar, place) in freevars.iter().zip(places) { let var_name = tcx.hir.name(freevar.var_id()); struct_fmt.field(&var_name.as_str(), place); } struct_fmt.field("$state", &places[freevars.len()]); for i in (freevars.len() + 1)..places.len() { struct_fmt.field(&format!("${}", i - freevars.len() - 1), &places[i]); } }); struct_fmt.finish() } else { write!(fmt, "[generator]") } }), } } } } } /////////////////////////////////////////////////////////////////////////// /// Constants /// /// Two constants are equal if they are the same constant. Note that /// this does not necessarily mean that they are "==" in Rust -- in /// particular one must be wary of `NaN`! #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub struct Constant<'tcx> { pub span: Span, pub ty: Ty<'tcx>, pub literal: Literal<'tcx>, } newtype_index!(Promoted { DEBUG_FORMAT = "promoted[{}]" }); #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub enum Literal<'tcx> { Value { value: &'tcx ty::Const<'tcx>, }, Promoted { // Index into the `promoted` vector of `Mir`. index: Promoted }, } impl<'tcx> Debug for Constant<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { write!(fmt, "{:?}", self.literal) } } impl<'tcx> Debug for Literal<'tcx> { fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { use self::Literal::*; match *self { Value { value } => { write!(fmt, "const ")?; fmt_const_val(fmt, value) } Promoted { index } => { write!(fmt, "{:?}", index) } } } } /// Write a `ConstVal` in a way closer to the original source code than the `Debug` output. pub fn fmt_const_val(fmt: &mut W, const_val: &ty::Const) -> fmt::Result { use middle::const_val::ConstVal; match const_val.val { ConstVal::Unevaluated(..) => write!(fmt, "{:?}", const_val), ConstVal::Value(val) => { if let Some(value) = val.to_byval_value() { print_miri_value(value, const_val.ty, fmt) } else { write!(fmt, "{:?}:{}", val, const_val.ty) } }, } } pub fn print_miri_value(value: Value, ty: Ty, f: &mut W) -> fmt::Result { use ty::TypeVariants::*; match (value, &ty.sty) { (Value::Scalar(Scalar::Bits { bits: 0, .. }), &TyBool) => write!(f, "false"), (Value::Scalar(Scalar::Bits { bits: 1, .. }), &TyBool) => write!(f, "true"), (Value::Scalar(Scalar::Bits { bits, .. }), &TyFloat(ast::FloatTy::F32)) => write!(f, "{}f32", Single::from_bits(bits)), (Value::Scalar(Scalar::Bits { bits, .. }), &TyFloat(ast::FloatTy::F64)) => write!(f, "{}f64", Double::from_bits(bits)), (Value::Scalar(Scalar::Bits { bits, .. }), &TyUint(ui)) => write!(f, "{:?}{}", bits, ui), (Value::Scalar(Scalar::Bits { bits, .. }), &TyInt(i)) => { let bit_width = ty::tls::with(|tcx| { let ty = tcx.lift_to_global(&ty).unwrap(); tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size.bits() }); let shift = 128 - bit_width; write!(f, "{:?}{}", ((bits as i128) << shift) >> shift, i) }, (Value::Scalar(Scalar::Bits { bits, .. }), &TyChar) => write!(f, "{:?}", ::std::char::from_u32(bits as u32).unwrap()), (_, &TyFnDef(did, _)) => write!(f, "{}", item_path_str(did)), (Value::ScalarPair(Scalar::Ptr(ptr), Scalar::Bits { bits: len, .. }), &TyRef(_, &ty::TyS { sty: TyStr, .. }, _)) => { ty::tls::with(|tcx| { match tcx.alloc_map.lock().get(ptr.alloc_id) { Some(interpret::AllocType::Memory(alloc)) => { assert_eq!(len as usize as u128, len); let slice = &alloc.bytes[(ptr.offset.bytes() as usize)..][..(len as usize)]; let s = ::std::str::from_utf8(slice) .expect("non utf8 str from miri"); write!(f, "{:?}", s) } _ => write!(f, "pointer to erroneous constant {:?}, {:?}", ptr, len), } }) }, _ => write!(f, "{:?}:{}", value, ty), } } fn item_path_str(def_id: DefId) -> String { ty::tls::with(|tcx| tcx.item_path_str(def_id)) } impl<'tcx> ControlFlowGraph for Mir<'tcx> { type Node = BasicBlock; fn num_nodes(&self) -> usize { self.basic_blocks.len() } fn start_node(&self) -> Self::Node { START_BLOCK } fn predecessors<'graph>(&'graph self, node: Self::Node) -> >::Iter { self.predecessors_for(node).clone().into_iter() } fn successors<'graph>(&'graph self, node: Self::Node) -> >::Iter { self.basic_blocks[node].terminator().successors().cloned() } } impl<'a, 'b> GraphPredecessors<'b> for Mir<'a> { type Item = BasicBlock; type Iter = IntoIter; } impl<'a, 'b> GraphSuccessors<'b> for Mir<'a> { type Item = BasicBlock; type Iter = iter::Cloned>; } #[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd)] pub struct Location { /// the location is within this block pub block: BasicBlock, /// the location is the start of the statement; or, if `statement_index` /// == num-statements, then the start of the terminator. pub statement_index: usize, } impl fmt::Debug for Location { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { write!(fmt, "{:?}[{}]", self.block, self.statement_index) } } impl Location { pub const START: Location = Location { block: START_BLOCK, statement_index: 0, }; /// Returns the location immediately after this one within the enclosing block. /// /// Note that if this location represents a terminator, then the /// resulting location would be out of bounds and invalid. pub fn successor_within_block(&self) -> Location { Location { block: self.block, statement_index: self.statement_index + 1 } } pub fn dominates(&self, other: Location, dominators: &Dominators) -> bool { if self.block == other.block { self.statement_index <= other.statement_index } else { dominators.is_dominated_by(other.block, self.block) } } } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub enum UnsafetyViolationKind { General, ExternStatic(ast::NodeId), BorrowPacked(ast::NodeId), } #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub struct UnsafetyViolation { pub source_info: SourceInfo, pub description: InternedString, pub kind: UnsafetyViolationKind, } #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)] pub struct UnsafetyCheckResult { /// Violations that are propagated *upwards* from this function pub violations: Lrc<[UnsafetyViolation]>, /// unsafe blocks in this function, along with whether they are used. This is /// used for the "unused_unsafe" lint. pub unsafe_blocks: Lrc<[(ast::NodeId, bool)]>, } /// The layout of generator state #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct GeneratorLayout<'tcx> { pub fields: Vec>, } #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct BorrowCheckResult<'gcx> { pub closure_requirements: Option>, pub used_mut_upvars: SmallVec<[Field; 8]>, } /// After we borrow check a closure, we are left with various /// requirements that we have inferred between the free regions that /// appear in the closure's signature or on its field types. These /// requirements are then verified and proved by the closure's /// creating function. This struct encodes those requirements. /// /// The requirements are listed as being between various /// `RegionVid`. The 0th region refers to `'static`; subsequent region /// vids refer to the free regions that appear in the closure (or /// generator's) type, in order of appearance. (This numbering is /// actually defined by the `UniversalRegions` struct in the NLL /// region checker. See for example /// `UniversalRegions::closure_mapping`.) Note that we treat the free /// regions in the closure's type "as if" they were erased, so their /// precise identity is not important, only their position. /// /// Example: If type check produces a closure with the closure substs: /// /// ```text /// ClosureSubsts = [ /// i8, // the "closure kind" /// for<'x> fn(&'a &'x u32) -> &'x u32, // the "closure signature" /// &'a String, // some upvar /// ] /// ``` /// /// here, there is one unique free region (`'a`) but it appears /// twice. We would "renumber" each occurrence to a unique vid, as follows: /// /// ```text /// ClosureSubsts = [ /// i8, // the "closure kind" /// for<'x> fn(&'1 &'x u32) -> &'x u32, // the "closure signature" /// &'2 String, // some upvar /// ] /// ``` /// /// Now the code might impose a requirement like `'1: '2`. When an /// instance of the closure is created, the corresponding free regions /// can be extracted from its type and constrained to have the given /// outlives relationship. /// /// In some cases, we have to record outlives requirements between /// types and regions as well. In that case, if those types include /// any regions, those regions are recorded as `ReClosureBound` /// instances assigned one of these same indices. Those regions will /// be substituted away by the creator. We use `ReClosureBound` in /// that case because the regions must be allocated in the global /// TyCtxt, and hence we cannot use `ReVar` (which is what we use /// internally within the rest of the NLL code). #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] pub struct ClosureRegionRequirements<'gcx> { /// The number of external regions defined on the closure. In our /// example above, it would be 3 -- one for `'static`, then `'1` /// and `'2`. This is just used for a sanity check later on, to /// make sure that the number of regions we see at the callsite /// matches. pub num_external_vids: usize, /// Requirements between the various free regions defined in /// indices. pub outlives_requirements: Vec>, } /// Indicates an outlives constraint between a type or between two /// free-regions declared on the closure. #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)] pub struct ClosureOutlivesRequirement<'tcx> { // This region or type ... pub subject: ClosureOutlivesSubject<'tcx>, // .. must outlive this one. pub outlived_free_region: ty::RegionVid, // If not, report an error here. pub blame_span: Span, } /// The subject of a ClosureOutlivesRequirement -- that is, the thing /// that must outlive some region. #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable)] pub enum ClosureOutlivesSubject<'tcx> { /// Subject is a type, typically a type parameter, but could also /// be a projection. Indicates a requirement like `T: 'a` being /// passed to the caller, where the type here is `T`. /// /// The type here is guaranteed not to contain any free regions at /// present. Ty(Ty<'tcx>), /// Subject is a free region from the closure. Indicates a requirement /// like `'a: 'b` being passed to the caller; the region here is `'a`. Region(ty::RegionVid), } /* * TypeFoldable implementations for MIR types */ CloneTypeFoldableAndLiftImpls! { Mutability, SourceInfo, UpvarDecl, ValidationOp, SourceScope, SourceScopeData, SourceScopeLocalData, } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for Mir<'tcx> { basic_blocks, source_scopes, source_scope_local_data, promoted, yield_ty, generator_drop, generator_layout, local_decls, arg_count, upvar_decls, spread_arg, span, cache, } } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for GeneratorLayout<'tcx> { fields } } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for LocalDecl<'tcx> { mutability, is_user_variable, internal, ty, name, syntactic_source_info, visibility_source_info, } } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for BasicBlockData<'tcx> { statements, terminator, is_cleanup, } } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for ValidationOperand<'tcx, Place<'tcx>> { place, ty, re, mutbl } } BraceStructTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for Statement<'tcx> { source_info, kind } } EnumTypeFoldableImpl! { impl<'tcx> TypeFoldable<'tcx> for StatementKind<'tcx> { (StatementKind::Assign)(a, b), (StatementKind::ReadForMatch)(place), (StatementKind::SetDiscriminant) { place, variant_index }, (StatementKind::StorageLive)(a), (StatementKind::StorageDead)(a), (StatementKind::InlineAsm) { asm, outputs, inputs }, (StatementKind::Validate)(a, b), (StatementKind::EndRegion)(a), (StatementKind::UserAssertTy)(a, b), (StatementKind::Nop), } } EnumTypeFoldableImpl! { impl<'tcx, T> TypeFoldable<'tcx> for ClearCrossCrate { (ClearCrossCrate::Clear), (ClearCrossCrate::Set)(a), } where T: TypeFoldable<'tcx> } impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { use mir::TerminatorKind::*; let kind = match self.kind { Goto { target } => Goto { target: target }, SwitchInt { ref discr, switch_ty, ref values, ref targets } => SwitchInt { discr: discr.fold_with(folder), switch_ty: switch_ty.fold_with(folder), values: values.clone(), targets: targets.clone() }, Drop { ref location, target, unwind } => Drop { location: location.fold_with(folder), target, unwind, }, DropAndReplace { ref location, ref value, target, unwind } => DropAndReplace { location: location.fold_with(folder), value: value.fold_with(folder), target, unwind, }, Yield { ref value, resume, drop } => Yield { value: value.fold_with(folder), resume: resume, drop: drop, }, Call { ref func, ref args, ref destination, cleanup } => { let dest = destination.as_ref().map(|&(ref loc, dest)| { (loc.fold_with(folder), dest) }); Call { func: func.fold_with(folder), args: args.fold_with(folder), destination: dest, cleanup, } }, Assert { ref cond, expected, ref msg, target, cleanup } => { let msg = if let EvalErrorKind::BoundsCheck { ref len, ref index } = *msg { EvalErrorKind::BoundsCheck { len: len.fold_with(folder), index: index.fold_with(folder), } } else { msg.clone() }; Assert { cond: cond.fold_with(folder), expected, msg, target, cleanup, } }, GeneratorDrop => GeneratorDrop, Resume => Resume, Abort => Abort, Return => Return, Unreachable => Unreachable, FalseEdges { real_target, ref imaginary_targets } => FalseEdges { real_target, imaginary_targets: imaginary_targets.clone() }, FalseUnwind { real_target, unwind } => FalseUnwind { real_target, unwind }, }; Terminator { source_info: self.source_info, kind, } } fn super_visit_with>(&self, visitor: &mut V) -> bool { use mir::TerminatorKind::*; match self.kind { SwitchInt { ref discr, switch_ty, .. } => discr.visit_with(visitor) || switch_ty.visit_with(visitor), Drop { ref location, ..} => location.visit_with(visitor), DropAndReplace { ref location, ref value, ..} => location.visit_with(visitor) || value.visit_with(visitor), Yield { ref value, ..} => value.visit_with(visitor), Call { ref func, ref args, ref destination, .. } => { let dest = if let Some((ref loc, _)) = *destination { loc.visit_with(visitor) } else { false }; dest || func.visit_with(visitor) || args.visit_with(visitor) }, Assert { ref cond, ref msg, .. } => { if cond.visit_with(visitor) { if let EvalErrorKind::BoundsCheck { ref len, ref index } = *msg { len.visit_with(visitor) || index.visit_with(visitor) } else { false } } else { false } }, Goto { .. } | Resume | Abort | Return | GeneratorDrop | Unreachable | FalseEdges { .. } | FalseUnwind { .. } => false } } } impl<'tcx> TypeFoldable<'tcx> for Place<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { match self { &Place::Projection(ref p) => Place::Projection(p.fold_with(folder)), _ => self.clone() } } fn super_visit_with>(&self, visitor: &mut V) -> bool { if let &Place::Projection(ref p) = self { p.visit_with(visitor) } else { false } } } impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { use mir::Rvalue::*; match *self { Use(ref op) => Use(op.fold_with(folder)), Repeat(ref op, len) => Repeat(op.fold_with(folder), len), Ref(region, bk, ref place) => Ref(region.fold_with(folder), bk, place.fold_with(folder)), Len(ref place) => Len(place.fold_with(folder)), Cast(kind, ref op, ty) => Cast(kind, op.fold_with(folder), ty.fold_with(folder)), BinaryOp(op, ref rhs, ref lhs) => BinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)), CheckedBinaryOp(op, ref rhs, ref lhs) => CheckedBinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)), UnaryOp(op, ref val) => UnaryOp(op, val.fold_with(folder)), Discriminant(ref place) => Discriminant(place.fold_with(folder)), NullaryOp(op, ty) => NullaryOp(op, ty.fold_with(folder)), Aggregate(ref kind, ref fields) => { let kind = box match **kind { AggregateKind::Array(ty) => AggregateKind::Array(ty.fold_with(folder)), AggregateKind::Tuple => AggregateKind::Tuple, AggregateKind::Adt(def, v, substs, n) => AggregateKind::Adt(def, v, substs.fold_with(folder), n), AggregateKind::Closure(id, substs) => AggregateKind::Closure(id, substs.fold_with(folder)), AggregateKind::Generator(id, substs, movablity) => AggregateKind::Generator(id, substs.fold_with(folder), movablity), }; Aggregate(kind, fields.fold_with(folder)) } } } fn super_visit_with>(&self, visitor: &mut V) -> bool { use mir::Rvalue::*; match *self { Use(ref op) => op.visit_with(visitor), Repeat(ref op, _) => op.visit_with(visitor), Ref(region, _, ref place) => region.visit_with(visitor) || place.visit_with(visitor), Len(ref place) => place.visit_with(visitor), Cast(_, ref op, ty) => op.visit_with(visitor) || ty.visit_with(visitor), BinaryOp(_, ref rhs, ref lhs) | CheckedBinaryOp(_, ref rhs, ref lhs) => rhs.visit_with(visitor) || lhs.visit_with(visitor), UnaryOp(_, ref val) => val.visit_with(visitor), Discriminant(ref place) => place.visit_with(visitor), NullaryOp(_, ty) => ty.visit_with(visitor), Aggregate(ref kind, ref fields) => { (match **kind { AggregateKind::Array(ty) => ty.visit_with(visitor), AggregateKind::Tuple => false, AggregateKind::Adt(_, _, substs, _) => substs.visit_with(visitor), AggregateKind::Closure(_, substs) => substs.visit_with(visitor), AggregateKind::Generator(_, substs, _) => substs.visit_with(visitor), }) || fields.visit_with(visitor) } } } } impl<'tcx> TypeFoldable<'tcx> for Operand<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { match *self { Operand::Copy(ref place) => Operand::Copy(place.fold_with(folder)), Operand::Move(ref place) => Operand::Move(place.fold_with(folder)), Operand::Constant(ref c) => Operand::Constant(c.fold_with(folder)), } } fn super_visit_with>(&self, visitor: &mut V) -> bool { match *self { Operand::Copy(ref place) | Operand::Move(ref place) => place.visit_with(visitor), Operand::Constant(ref c) => c.visit_with(visitor) } } } impl<'tcx, B, V, T> TypeFoldable<'tcx> for Projection<'tcx, B, V, T> where B: TypeFoldable<'tcx>, V: TypeFoldable<'tcx>, T: TypeFoldable<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { use mir::ProjectionElem::*; let base = self.base.fold_with(folder); let elem = match self.elem { Deref => Deref, Field(f, ref ty) => Field(f, ty.fold_with(folder)), Index(ref v) => Index(v.fold_with(folder)), ref elem => elem.clone() }; Projection { base, elem, } } fn super_visit_with>(&self, visitor: &mut Vs) -> bool { use mir::ProjectionElem::*; self.base.visit_with(visitor) || match self.elem { Field(_, ref ty) => ty.visit_with(visitor), Index(ref v) => v.visit_with(visitor), _ => false } } } impl<'tcx> TypeFoldable<'tcx> for Field { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, _: &mut F) -> Self { *self } fn super_visit_with>(&self, _: &mut V) -> bool { false } } impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { Constant { span: self.span.clone(), ty: self.ty.fold_with(folder), literal: self.literal.fold_with(folder) } } fn super_visit_with>(&self, visitor: &mut V) -> bool { self.ty.visit_with(visitor) || self.literal.visit_with(visitor) } } impl<'tcx> TypeFoldable<'tcx> for Literal<'tcx> { fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self { match *self { Literal::Value { value } => Literal::Value { value: value.fold_with(folder) }, Literal::Promoted { index } => Literal::Promoted { index } } } fn super_visit_with>(&self, visitor: &mut V) -> bool { match *self { Literal::Value { value } => value.visit_with(visitor), Literal::Promoted { .. } => false } } }