| // ignore-tidy-filelength |
| |
| //! MIR datatypes and passes. See the [rustc guide] for more info. |
| //! |
| //! [rustc guide]: https://rust-lang.github.io/rustc-guide/mir/index.html |
| |
| use crate::hir::def::{CtorKind, Namespace}; |
| use crate::hir::def_id::DefId; |
| use crate::hir::{self, InlineAsm as HirInlineAsm}; |
| use crate::mir::interpret::{ConstValue, PanicInfo, Scalar}; |
| use crate::mir::visit::MirVisitable; |
| use crate::ty::adjustment::PointerCast; |
| use crate::ty::fold::{TypeFoldable, TypeFolder, TypeVisitor}; |
| use crate::ty::layout::VariantIdx; |
| use crate::ty::print::{FmtPrinter, Printer}; |
| use crate::ty::subst::{Subst, SubstsRef}; |
| use crate::ty::{ |
| self, AdtDef, CanonicalUserTypeAnnotations, ClosureSubsts, GeneratorSubsts, Region, Ty, TyCtxt, |
| UserTypeAnnotationIndex, |
| }; |
| |
| use polonius_engine::Atom; |
| use rustc_data_structures::bit_set::BitMatrix; |
| use rustc_data_structures::fx::FxHashSet; |
| use rustc_data_structures::graph::dominators::{dominators, Dominators}; |
| use rustc_data_structures::graph::{self, GraphPredecessors, GraphSuccessors}; |
| use rustc_data_structures::indexed_vec::{Idx, IndexVec}; |
| use rustc_data_structures::sync::Lrc; |
| use rustc_data_structures::sync::MappedReadGuard; |
| use rustc_macros::HashStable; |
| use rustc_serialize::{Encodable, Decodable}; |
| use smallvec::SmallVec; |
| use std::borrow::Cow; |
| use std::fmt::{self, Debug, Display, Formatter, Write}; |
| use std::ops::{Index, IndexMut}; |
| use std::slice; |
| use std::vec::IntoIter; |
| use std::{iter, mem, option, u32}; |
| use syntax::ast::Name; |
| use syntax::symbol::{InternedString, Symbol}; |
| use syntax_pos::{Span, DUMMY_SP}; |
| |
| pub use crate::mir::interpret::AssertMessage; |
| |
| mod cache; |
| pub mod interpret; |
| pub mod mono; |
| pub mod tcx; |
| pub mod traversal; |
| pub mod visit; |
| |
| /// Types for locals |
| type LocalDecls<'tcx> = IndexVec<Local, LocalDecl<'tcx>>; |
| |
| 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 Body<'tcx> { |
| fn local_decls(&self) -> &LocalDecls<'tcx> { |
| &self.local_decls |
| } |
| } |
| |
| /// The various "big phases" that MIR goes through. |
| /// |
| /// Warning: ordering of variants is significant. |
| #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq, PartialOrd, Ord)] |
| pub enum MirPhase { |
| Build = 0, |
| Const = 1, |
| Validated = 2, |
| Optimized = 3, |
| } |
| |
| impl MirPhase { |
| /// Gets the index of the current MirPhase within the set of all `MirPhase`s. |
| pub fn phase_index(&self) -> usize { |
| *self as usize |
| } |
| } |
| |
| /// The lowered representation of a single function. |
| #[derive(Clone, RustcEncodable, RustcDecodable, Debug)] |
| pub struct Body<'tcx> { |
| /// A list of basic blocks. References to basic block use a newtyped index type `BasicBlock` |
| /// that indexes into this vector. |
| basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, |
| |
| /// Records how far through the "desugaring and optimization" process this particular |
| /// MIR has traversed. This is particularly useful when inlining, since in that context |
| /// we instantiate the promoted constants and add them to our promoted vector -- but those |
| /// promoted items have already been optimized, whereas ours have not. This field allows |
| /// us to see the difference and forego optimization on the inlined promoted items. |
| pub phase: MirPhase, |
| |
| /// A list of source scopes; these are referenced by statements |
| /// and used for debuginfo. Indexed by a `SourceScope`. |
| pub source_scopes: IndexVec<SourceScope, SourceScopeData>, |
| |
| /// Crate-local information for each source scope, that can't (and |
| /// needn't) be tracked across crates. |
| pub source_scope_local_data: ClearCrossCrate<IndexVec<SourceScope, SourceScopeLocalData>>, |
| |
| /// The yield type of the function, if it is a generator. |
| pub yield_ty: Option<Ty<'tcx>>, |
| |
| /// Generator drop glue. |
| pub generator_drop: Option<Box<Body<'tcx>>>, |
| |
| /// The layout of a generator. Produced by the state transformation. |
| pub generator_layout: Option<GeneratorLayout<'tcx>>, |
| |
| /// 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>, |
| |
| /// User type annotations. |
| pub user_type_annotations: CanonicalUserTypeAnnotations<'tcx>, |
| |
| /// The 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, |
| |
| /// 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<Local>, |
| |
| /// Names and capture modes of all the closure upvars, assuming |
| /// the first argument is either the closure or a reference to it. |
| // |
| // NOTE(eddyb) This is *strictly* a temporary hack for codegen |
| // debuginfo generation, and will be removed at some point. |
| // Do **NOT** use it for anything else; upvar information should not be |
| // in the MIR, so please rely on local crate HIR or other side-channels. |
| pub __upvar_debuginfo_codegen_only_do_not_use: Vec<UpvarDebuginfo>, |
| |
| /// Mark this MIR of a const context other than const functions as having converted a `&&` or |
| /// `||` expression into `&` or `|` respectively. This is problematic because if we ever stop |
| /// this conversion from happening and use short circuiting, we will cause the following code |
| /// to change the value of `x`: `let mut x = 42; false && { x = 55; true };` |
| /// |
| /// List of places where control flow was destroyed. Used for error reporting. |
| pub control_flow_destroyed: Vec<(Span, String)>, |
| |
| /// A span representing this MIR, for error reporting. |
| pub span: Span, |
| |
| /// A cache for various calculations. |
| cache: cache::Cache, |
| } |
| |
| impl<'tcx> Body<'tcx> { |
| pub fn new( |
| basic_blocks: IndexVec<BasicBlock, BasicBlockData<'tcx>>, |
| source_scopes: IndexVec<SourceScope, SourceScopeData>, |
| source_scope_local_data: ClearCrossCrate<IndexVec<SourceScope, SourceScopeLocalData>>, |
| yield_ty: Option<Ty<'tcx>>, |
| local_decls: LocalDecls<'tcx>, |
| user_type_annotations: CanonicalUserTypeAnnotations<'tcx>, |
| arg_count: usize, |
| __upvar_debuginfo_codegen_only_do_not_use: Vec<UpvarDebuginfo>, |
| span: Span, |
| control_flow_destroyed: Vec<(Span, String)>, |
| ) -> 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() |
| ); |
| |
| Body { |
| phase: MirPhase::Build, |
| basic_blocks, |
| source_scopes, |
| source_scope_local_data, |
| yield_ty, |
| generator_drop: None, |
| generator_layout: None, |
| local_decls, |
| user_type_annotations, |
| arg_count, |
| __upvar_debuginfo_codegen_only_do_not_use, |
| spread_arg: None, |
| span, |
| cache: cache::Cache::new(), |
| control_flow_destroyed, |
| } |
| } |
| |
| #[inline] |
| pub fn basic_blocks(&self) -> &IndexVec<BasicBlock, BasicBlockData<'tcx>> { |
| &self.basic_blocks |
| } |
| |
| #[inline] |
| pub fn basic_blocks_mut(&mut self) -> &mut IndexVec<BasicBlock, BasicBlockData<'tcx>> { |
| self.cache.invalidate(); |
| &mut self.basic_blocks |
| } |
| |
| #[inline] |
| pub fn basic_blocks_and_local_decls_mut( |
| &mut self, |
| ) -> (&mut IndexVec<BasicBlock, BasicBlockData<'tcx>>, &mut LocalDecls<'tcx>) { |
| self.cache.invalidate(); |
| (&mut self.basic_blocks, &mut self.local_decls) |
| } |
| |
| #[inline] |
| pub fn predecessors(&self) -> MappedReadGuard<'_, IndexVec<BasicBlock, Vec<BasicBlock>>> { |
| self.cache.predecessors(self) |
| } |
| |
| #[inline] |
| pub fn predecessors_for(&self, bb: BasicBlock) -> MappedReadGuard<'_, Vec<BasicBlock>> { |
| MappedReadGuard::map(self.predecessors(), |p| &p[bb]) |
| } |
| |
| #[inline] |
| pub fn predecessor_locations(&self, loc: Location) -> impl Iterator<Item = Location> + '_ { |
| let if_zero_locations = if loc.statement_index == 0 { |
| let predecessor_blocks = self.predecessors_for(loc.block); |
| let num_predecessor_blocks = predecessor_blocks.len(); |
| Some( |
| (0..num_predecessor_blocks) |
| .map(move |i| predecessor_blocks[i]) |
| .map(move |bb| self.terminator_loc(bb)), |
| ) |
| } else { |
| None |
| }; |
| |
| let if_not_zero_locations = if loc.statement_index == 0 { |
| None |
| } else { |
| Some(Location { block: loc.block, statement_index: loc.statement_index - 1 }) |
| }; |
| |
| if_zero_locations.into_iter().flatten().chain(if_not_zero_locations) |
| } |
| |
| #[inline] |
| pub fn dominators(&self) -> Dominators<BasicBlock> { |
| dominators(self) |
| } |
| |
| #[inline] |
| pub fn local_kind(&self, local: Local) -> LocalKind { |
| let index = local.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 { |
| LocalKind::Temp |
| } |
| } |
| |
| /// Returns an iterator over all temporaries. |
| #[inline] |
| pub fn temps_iter<'a>(&'a self) -> impl Iterator<Item = Local> + '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.is_some() { |
| None |
| } else { |
| Some(local) |
| } |
| }) |
| } |
| |
| /// Returns an iterator over all user-declared locals. |
| #[inline] |
| pub fn vars_iter<'a>(&'a self) -> impl Iterator<Item = Local> + '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.is_some() { |
| Some(local) |
| } else { |
| None |
| } |
| }) |
| } |
| |
| /// Returns an iterator over all user-declared mutable locals. |
| #[inline] |
| pub fn mut_vars_iter<'a>(&'a self) -> impl Iterator<Item = Local> + 'a { |
| (self.arg_count + 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.is_some() && decl.mutability == Mutability::Mut { |
| 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<Item = Local> + '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.is_some() || 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<Item = Local> { |
| let arg_count = self.arg_count; |
| (1..=arg_count).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<Item = Local> { |
| 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_eq!(idx, stmts.len()); |
| &block.terminator().source_info |
| } |
| } |
| |
| /// Checks if `sub` is a sub scope of `sup` |
| pub fn is_sub_scope(&self, mut sub: SourceScope, sup: SourceScope) -> bool { |
| while sub != sup { |
| match self.source_scopes[sub].parent_scope { |
| None => return false, |
| Some(p) => sub = p, |
| } |
| } |
| true |
| } |
| |
| /// Returns 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 |
| } |
| |
| /// Gets the location of the terminator for the given block. |
| pub fn terminator_loc(&self, bb: BasicBlock) -> Location { |
| Location { block: bb, statement_index: self[bb].statements.len() } |
| } |
| } |
| |
| #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub enum Safety { |
| Safe, |
| /// Unsafe because of a PushUnsafeBlock |
| BuiltinUnsafe, |
| /// Unsafe because of an unsafe fn |
| FnUnsafe, |
| /// Unsafe because of an `unsafe` block |
| ExplicitUnsafe(hir::HirId), |
| } |
| |
| impl_stable_hash_for!(struct Body<'tcx> { |
| phase, |
| basic_blocks, |
| source_scopes, |
| source_scope_local_data, |
| yield_ty, |
| generator_drop, |
| generator_layout, |
| local_decls, |
| user_type_annotations, |
| arg_count, |
| __upvar_debuginfo_codegen_only_do_not_use, |
| spread_arg, |
| control_flow_destroyed, |
| span, |
| cache |
| }); |
| |
| impl<'tcx> Index<BasicBlock> for Body<'tcx> { |
| type Output = BasicBlockData<'tcx>; |
| |
| #[inline] |
| fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> { |
| &self.basic_blocks()[index] |
| } |
| } |
| |
| impl<'tcx> IndexMut<BasicBlock> for Body<'tcx> { |
| #[inline] |
| fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> { |
| &mut self.basic_blocks_mut()[index] |
| } |
| } |
| |
| #[derive(Copy, Clone, Debug, HashStable)] |
| pub enum ClearCrossCrate<T> { |
| Clear, |
| Set(T), |
| } |
| |
| impl<T> ClearCrossCrate<T> { |
| pub fn assert_crate_local(self) -> T { |
| match self { |
| ClearCrossCrate::Clear => bug!("unwrapping cross-crate data"), |
| ClearCrossCrate::Set(v) => v, |
| } |
| } |
| } |
| |
| impl<T: Encodable> rustc_serialize::UseSpecializedEncodable for ClearCrossCrate<T> {} |
| impl<T: Decodable> rustc_serialize::UseSpecializedDecodable for ClearCrossCrate<T> {} |
| |
| /// 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, HashStable)] |
| pub struct SourceInfo { |
| /// The 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, HashStable)] |
| pub enum Mutability { |
| Mut, |
| Not, |
| } |
| |
| impl From<Mutability> for hir::Mutability { |
| fn from(m: Mutability) -> Self { |
| match m { |
| Mutability::Mut => hir::MutMutable, |
| Mutability::Not => hir::MutImmutable, |
| } |
| } |
| } |
| |
| #[derive( |
| Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, RustcEncodable, RustcDecodable, HashStable, |
| )] |
| pub enum BorrowKind { |
| /// Data must be immutable and is aliasable. |
| Shared, |
| |
| /// The immediately borrowed place must be immutable, but projections from |
| /// it don't need to be. For example, a shallow borrow of `a.b` doesn't |
| /// conflict with a mutable borrow of `a.b.c`. |
| /// |
| /// This is used when lowering matches: when matching on a place we want to |
| /// ensure that place have the same value from the start of the match until |
| /// an arm is selected. This prevents this code from compiling: |
| /// |
| /// let mut x = &Some(0); |
| /// match *x { |
| /// None => (), |
| /// Some(_) if { x = &None; false } => (), |
| /// Some(_) => (), |
| /// } |
| /// |
| /// This can't be a shared borrow because mutably borrowing (*x as Some).0 |
| /// should not prevent `if let None = x { ... }`, for example, because the |
| /// mutating `(*x as Some).0` can't affect the discriminant of `x`. |
| /// We can also report errors with this kind of borrow differently. |
| Shallow, |
| |
| /// 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 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 an `&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::Shallow | BorrowKind::Unique => false, |
| BorrowKind::Mut { allow_two_phase_borrow } => allow_two_phase_borrow, |
| } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Variables and temps |
| |
| newtype_index! { |
| pub struct Local { |
| derive [HashStable] |
| DEBUG_FORMAT = "_{}", |
| const RETURN_PLACE = 0, |
| } |
| } |
| |
| impl Atom for Local { |
| fn index(self) -> usize { |
| Idx::index(self) |
| } |
| } |
| |
| /// Classifies locals into categories. See `Body::local_kind`. |
| #[derive(PartialEq, Eq, Debug, HashStable)] |
| pub enum LocalKind { |
| /// User-declared variable binding. |
| Var, |
| /// Compiler-introduced temporary. |
| Temp, |
| /// Function argument. |
| Arg, |
| /// Location of function's return value. |
| ReturnPointer, |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)] |
| pub struct VarBindingForm<'tcx> { |
| /// Is variable bound via `x`, `mut x`, `ref x`, or `ref mut x`? |
| pub binding_mode: ty::BindingMode, |
| /// If an explicit type was provided for this variable binding, |
| /// this holds the source Span of that type. |
| /// |
| /// NOTE: if you want to change this to a `HirId`, be wary that |
| /// doing so breaks incremental compilation (as of this writing), |
| /// while a `Span` does not cause our tests to fail. |
| pub opt_ty_info: Option<Span>, |
| /// Place of the RHS of the =, or the subject of the `match` where this |
| /// variable is initialized. None in the case of `let PATTERN;`. |
| /// Some((None, ..)) in the case of and `let [mut] x = ...` because |
| /// (a) the right-hand side isn't evaluated as a place expression. |
| /// (b) it gives a way to separate this case from the remaining cases |
| /// for diagnostics. |
| pub opt_match_place: Option<(Option<Place<'tcx>>, Span)>, |
| /// The span of the pattern in which this variable was bound. |
| pub pat_span: Span, |
| } |
| |
| #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)] |
| pub enum BindingForm<'tcx> { |
| /// This is a binding for a non-`self` binding, or a `self` that has an explicit type. |
| Var(VarBindingForm<'tcx>), |
| /// Binding for a `self`/`&self`/`&mut self` binding where the type is implicit. |
| ImplicitSelf(ImplicitSelfKind), |
| /// Reference used in a guard expression to ensure immutability. |
| RefForGuard, |
| } |
| |
| /// Represents what type of implicit self a function has, if any. |
| #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable)] |
| pub enum ImplicitSelfKind { |
| /// Represents a `fn x(self);`. |
| Imm, |
| /// Represents a `fn x(mut self);`. |
| Mut, |
| /// Represents a `fn x(&self);`. |
| ImmRef, |
| /// Represents a `fn x(&mut self);`. |
| MutRef, |
| /// Represents when a function does not have a self argument or |
| /// when a function has a `self: X` argument. |
| None, |
| } |
| |
| CloneTypeFoldableAndLiftImpls! { BindingForm<'tcx>, } |
| |
| impl_stable_hash_for!(struct self::VarBindingForm<'tcx> { |
| binding_mode, |
| opt_ty_info, |
| opt_match_place, |
| pat_span |
| }); |
| |
| impl_stable_hash_for!(enum self::ImplicitSelfKind { |
| Imm, |
| Mut, |
| ImmRef, |
| MutRef, |
| None |
| }); |
| |
| impl_stable_hash_for!(enum self::MirPhase { |
| Build, |
| Const, |
| Validated, |
| Optimized, |
| }); |
| |
| mod binding_form_impl { |
| use crate::ich::StableHashingContext; |
| use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableHasherResult}; |
| |
| impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for super::BindingForm<'tcx> { |
| fn hash_stable<W: StableHasherResult>( |
| &self, |
| hcx: &mut StableHashingContext<'a>, |
| hasher: &mut StableHasher<W>, |
| ) { |
| use super::BindingForm::*; |
| ::std::mem::discriminant(self).hash_stable(hcx, hasher); |
| |
| match self { |
| Var(binding) => binding.hash_stable(hcx, hasher), |
| ImplicitSelf(kind) => kind.hash_stable(hcx, hasher), |
| RefForGuard => (), |
| } |
| } |
| } |
| } |
| |
| /// `BlockTailInfo` is attached to the `LocalDecl` for temporaries |
| /// created during evaluation of expressions in a block tail |
| /// expression; that is, a block like `{ STMT_1; STMT_2; EXPR }`. |
| /// |
| /// It is used to improve diagnostics when such temporaries are |
| /// involved in borrow_check errors, e.g., explanations of where the |
| /// temporaries come from, when their destructors are run, and/or how |
| /// one might revise the code to satisfy the borrow checker's rules. |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable)] |
| pub struct BlockTailInfo { |
| /// If `true`, then the value resulting from evaluating this tail |
| /// expression is ignored by the block's expression context. |
| /// |
| /// Examples include `{ ...; tail };` and `let _ = { ...; tail };` |
| /// but not e.g., `let _x = { ...; tail };` |
| pub tail_result_is_ignored: bool, |
| } |
| |
| impl_stable_hash_for!(struct BlockTailInfo { tail_result_is_ignored }); |
| |
| /// 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, HashStable)] |
| pub struct LocalDecl<'tcx> { |
| /// Whether this is a mutable minding (i.e., `let x` or `let mut x`). |
| /// |
| /// Temporaries and the return place are always mutable. |
| pub mutability: Mutability, |
| |
| /// `Some(binding_mode)` if this corresponds to a user-declared local variable. |
| /// |
| /// This is solely used for local diagnostics when generating |
| /// warnings/errors when compiling the current crate, and |
| /// therefore it need not be visible across crates. pnkfelix |
| /// currently hypothesized we *need* to wrap this in a |
| /// `ClearCrossCrate` as long as it carries as `HirId`. |
| pub is_user_variable: Option<ClearCrossCrate<BindingForm<'tcx>>>, |
| |
| /// `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, |
| |
| /// If this local is a temporary and `is_block_tail` is `Some`, |
| /// then it is a temporary created for evaluation of some |
| /// subexpression of some block's tail expression (with no |
| /// intervening statement context). |
| pub is_block_tail: Option<BlockTailInfo>, |
| |
| /// The type of this local. |
| pub ty: Ty<'tcx>, |
| |
| /// If the user manually ascribed a type to this variable, |
| /// e.g., via `let x: T`, then we carry that type here. The MIR |
| /// borrow checker needs this information since it can affect |
| /// region inference. |
| pub user_ty: UserTypeProjections, |
| |
| /// The 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<Name>, |
| |
| /// 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 `source_info.scope` represent the |
| /// "syntactic" lint scope (with a variable being under its let |
| /// block) while the `visibility_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.source_info.scope |
| /// │ │← `x.parse().unwrap()` |
| /// │ │ |
| /// │ │ │← y.source_info.scope |
| /// │ │ |
| /// │ │ │{ let y: u32 } |
| /// │ │ │ |
| /// │ │ │← y.visibility_scope |
| /// │ │ │← `y + 2` |
| /// │ |
| /// │ │{ let x: u32 } |
| /// │ │← x.visibility_scope |
| /// │ │← `drop(x)` // This accesses `x: u32`. |
| /// ``` |
| pub source_info: SourceInfo, |
| |
| /// Source scope within which the local is visible (for debuginfo) |
| /// (see `source_info` for more details). |
| pub visibility_scope: SourceScope, |
| } |
| |
| impl<'tcx> LocalDecl<'tcx> { |
| /// Returns `true` only if local is a binding that can itself be |
| /// made mutable via the addition of the `mut` keyword, namely |
| /// something like the occurrences of `x` in: |
| /// - `fn foo(x: Type) { ... }`, |
| /// - `let x = ...`, |
| /// - or `match ... { C(x) => ... }` |
| pub fn can_be_made_mutable(&self) -> bool { |
| match self.is_user_variable { |
| Some(ClearCrossCrate::Set(BindingForm::Var(VarBindingForm { |
| binding_mode: ty::BindingMode::BindByValue(_), |
| opt_ty_info: _, |
| opt_match_place: _, |
| pat_span: _, |
| }))) => true, |
| |
| Some(ClearCrossCrate::Set(BindingForm::ImplicitSelf(ImplicitSelfKind::Imm))) => true, |
| |
| _ => false, |
| } |
| } |
| |
| /// Returns `true` if local is definitely not a `ref ident` or |
| /// `ref mut ident` binding. (Such bindings cannot be made into |
| /// mutable bindings, but the inverse does not necessarily hold). |
| pub fn is_nonref_binding(&self) -> bool { |
| match self.is_user_variable { |
| Some(ClearCrossCrate::Set(BindingForm::Var(VarBindingForm { |
| binding_mode: ty::BindingMode::BindByValue(_), |
| opt_ty_info: _, |
| opt_match_place: _, |
| pat_span: _, |
| }))) => true, |
| |
| Some(ClearCrossCrate::Set(BindingForm::ImplicitSelf(_))) => true, |
| |
| _ => false, |
| } |
| } |
| |
| /// Returns `true` if this is a reference to a variable bound in a `match` |
| /// expression that is used to access said variable for the guard of the |
| /// match arm. |
| pub fn is_ref_for_guard(&self) -> bool { |
| match self.is_user_variable { |
| Some(ClearCrossCrate::Set(BindingForm::RefForGuard)) => true, |
| _ => false, |
| } |
| } |
| |
| /// Returns `true` is the local is from a compiler desugaring, e.g., |
| /// `__next` from a `for` loop. |
| #[inline] |
| pub fn from_compiler_desugaring(&self) -> bool { |
| self.source_info.span.desugaring_kind().is_some() |
| } |
| |
| /// Creates a new `LocalDecl` for a temporary. |
| #[inline] |
| pub fn new_temp(ty: Ty<'tcx>, span: Span) -> Self { |
| Self::new_local(ty, Mutability::Mut, false, span) |
| } |
| |
| /// Converts `self` into same `LocalDecl` except tagged as immutable. |
| #[inline] |
| pub fn immutable(mut self) -> Self { |
| self.mutability = Mutability::Not; |
| self |
| } |
| |
| /// Converts `self` into same `LocalDecl` except tagged as internal temporary. |
| #[inline] |
| pub fn block_tail(mut self, info: BlockTailInfo) -> Self { |
| assert!(self.is_block_tail.is_none()); |
| self.is_block_tail = Some(info); |
| self |
| } |
| |
| /// Creates a new `LocalDecl` for a internal temporary. |
| #[inline] |
| pub fn new_internal(ty: Ty<'tcx>, span: Span) -> Self { |
| Self::new_local(ty, Mutability::Mut, true, span) |
| } |
| |
| #[inline] |
| fn new_local(ty: Ty<'tcx>, mutability: Mutability, internal: bool, span: Span) -> Self { |
| LocalDecl { |
| mutability, |
| ty, |
| user_ty: UserTypeProjections::none(), |
| name: None, |
| source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, |
| visibility_scope: OUTERMOST_SOURCE_SCOPE, |
| internal, |
| is_user_variable: None, |
| is_block_tail: None, |
| } |
| } |
| |
| /// 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, |
| user_ty: UserTypeProjections::none(), |
| source_info: SourceInfo { span, scope: OUTERMOST_SOURCE_SCOPE }, |
| visibility_scope: OUTERMOST_SOURCE_SCOPE, |
| internal: false, |
| is_block_tail: None, |
| name: None, // FIXME maybe we do want some name here? |
| is_user_variable: None, |
| } |
| } |
| } |
| |
| /// A closure capture, with its name and mode. |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct UpvarDebuginfo { |
| pub debug_name: Name, |
| |
| /// If true, the capture is behind a reference. |
| pub by_ref: bool, |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // BasicBlock |
| |
| newtype_index! { |
| pub struct BasicBlock { |
| derive [HashStable] |
| DEBUG_FORMAT = "bb{}", |
| const START_BLOCK = 0, |
| } |
| } |
| |
| impl BasicBlock { |
| pub fn start_location(self) -> Location { |
| Location { block: self, statement_index: 0 } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // BasicBlockData and Terminator |
| |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct BasicBlockData<'tcx> { |
| /// List of statements in this block. |
| pub statements: Vec<Statement<'tcx>>, |
| |
| /// Terminator for this block. |
| /// |
| /// N.B., 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<Terminator<'tcx>>, |
| |
| /// 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, HashStable)] |
| pub struct Terminator<'tcx> { |
| pub source_info: SourceInfo, |
| pub kind: TerminatorKind<'tcx>, |
| } |
| |
| #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)] |
| 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 { |
| /// The discriminant value being tested. |
| discr: Operand<'tcx>, |
| |
| /// The 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<BasicBlock> // 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<BasicBlock>, |
| }, |
| |
| /// 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<BasicBlock> }, |
| |
| /// 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 the |
| /// elaboration: |
| /// |
| /// ``` |
| /// BB0 { |
| /// DropAndReplace(P <- V, goto BB1, unwind BB2) |
| /// } |
| /// ``` |
| /// |
| /// becomes |
| /// |
| /// ``` |
| /// BB0 { |
| /// Drop(P, goto BB1, unwind BB2) |
| /// } |
| /// BB1 { |
| /// // P is now uninitialized |
| /// P <- V |
| /// } |
| /// BB2 { |
| /// // P is now uninitialized -- its dtor panicked |
| /// P <- V |
| /// } |
| /// ``` |
| DropAndReplace { |
| location: Place<'tcx>, |
| value: Operand<'tcx>, |
| target: BasicBlock, |
| unwind: Option<BasicBlock>, |
| }, |
| |
| /// 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<Operand<'tcx>>, |
| /// 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<BasicBlock>, |
| /// `true` if this is from a call in HIR rather than from an overloaded |
| /// operator. True for overloaded function call. |
| from_hir_call: bool, |
| }, |
| |
| /// 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<BasicBlock>, |
| }, |
| |
| /// 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<BasicBlock>, |
| }, |
| |
| /// 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, |
| /// A block control flow could conceptually jump to, but won't in |
| /// practice. |
| imaginary_target: BasicBlock, |
| }, |
| /// 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<BasicBlock>, |
| }, |
| } |
| |
| pub type Successors<'a> = |
| iter::Chain<option::IntoIter<&'a BasicBlock>, slice::Iter<'a, BasicBlock>>; |
| pub type SuccessorsMut<'a> = |
| iter::Chain<option::IntoIter<&'a mut BasicBlock>, 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(&self) -> Option<&Option<BasicBlock>> { |
| self.kind.unwind() |
| } |
| |
| pub fn unwind_mut(&mut self) -> Option<&mut Option<BasicBlock>> { |
| self.kind.unwind_mut() |
| } |
| } |
| |
| impl<'tcx> TerminatorKind<'tcx> { |
| pub fn if_( |
| tcx: TyCtxt<'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_target } => { |
| Some(real_target).into_iter().chain(slice::from_ref(imaginary_target)) |
| } |
| } |
| } |
| |
| 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_target } => { |
| Some(real_target).into_iter().chain(slice::from_mut(imaginary_target)) |
| } |
| } |
| } |
| |
| pub fn unwind(&self) -> Option<&Option<BasicBlock>> { |
| 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 unwind, .. } |
| | TerminatorKind::Assert { cleanup: ref unwind, .. } |
| | TerminatorKind::DropAndReplace { ref unwind, .. } |
| | TerminatorKind::Drop { ref unwind, .. } |
| | TerminatorKind::FalseUnwind { ref unwind, .. } => Some(unwind), |
| } |
| } |
| |
| pub fn unwind_mut(&mut self) -> Option<&mut Option<BasicBlock>> { |
| 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<Terminator<'tcx>>) -> 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<F>(&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<F, I>(&mut self, mut f: F) |
| where |
| F: FnMut(&mut Statement<'tcx>) -> Option<I>, |
| I: iter::TrustedLen<Item = Statement<'tcx>>, |
| { |
| // 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> { |
| /// Writes 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<W: Write>(&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"), |
| } |
| } |
| |
| /// Returns the list of labels for the edges to the successor basic blocks. |
| pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> { |
| use self::TerminatorKind::*; |
| match *self { |
| Return | Resume | Abort | Unreachable | GeneratorDrop => vec![], |
| Goto { .. } => vec!["".into()], |
| SwitchInt { ref values, switch_ty, .. } => ty::tls::with(|tcx| { |
| let param_env = ty::ParamEnv::empty(); |
| let switch_ty = tcx.lift_to_global(&switch_ty).unwrap(); |
| let size = tcx.layout_of(param_env.and(switch_ty)).unwrap().size; |
| values |
| .iter() |
| .map(|&u| { |
| tcx.mk_const(ty::Const { |
| val: ConstValue::Scalar(Scalar::from_uint(u, size).into()), |
| ty: switch_ty, |
| }) |
| .to_string() |
| .into() |
| }) |
| .chain(iter::once("otherwise".into())) |
| .collect() |
| }), |
| Call { destination: Some(_), cleanup: Some(_), .. } => { |
| vec!["return".into(), "unwind".into()] |
| } |
| Call { destination: Some(_), cleanup: None, .. } => vec!["return".into()], |
| Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into()], |
| Call { destination: None, cleanup: None, .. } => vec![], |
| Yield { drop: Some(_), .. } => vec!["resume".into(), "drop".into()], |
| Yield { drop: None, .. } => vec!["resume".into()], |
| DropAndReplace { unwind: None, .. } | Drop { unwind: None, .. } => { |
| vec!["return".into()] |
| } |
| DropAndReplace { unwind: Some(_), .. } | Drop { unwind: Some(_), .. } => { |
| vec!["return".into(), "unwind".into()] |
| } |
| Assert { cleanup: None, .. } => vec!["".into()], |
| Assert { .. } => vec!["success".into(), "unwind".into()], |
| FalseEdges { .. } => vec!["real".into(), "imaginary".into()], |
| FalseUnwind { unwind: Some(_), .. } => vec!["real".into(), "cleanup".into()], |
| FalseUnwind { unwind: None, .. } => vec!["real".into()], |
| } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Statements |
| |
| #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct Statement<'tcx> { |
| pub source_info: SourceInfo, |
| pub kind: StatementKind<'tcx>, |
| } |
| |
| // `Statement` is used a lot. Make sure it doesn't unintentionally get bigger. |
| #[cfg(target_arch = "x86_64")] |
| static_assert_size!(Statement<'_>, 32); |
| |
| impl Statement<'_> { |
| /// 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, HashStable)] |
| pub enum StatementKind<'tcx> { |
| /// Write the RHS Rvalue to the LHS Place. |
| Assign(Box<(Place<'tcx>, Rvalue<'tcx>)>), |
| |
| /// This represents all the reading that a pattern match may do |
| /// (e.g., inspecting constants and discriminant values), and the |
| /// kind of pattern it comes from. This is in order to adapt potential |
| /// error messages to these specific patterns. |
| /// |
| /// Note that this also is emitted for regular `let` bindings to ensure that locals that are |
| /// never accessed still get some sanity checks for, e.g., `let x: ! = ..;` |
| FakeRead(FakeReadCause, Box<Place<'tcx>>), |
| |
| /// Write the discriminant for a variant to the enum Place. |
| SetDiscriminant { place: Box<Place<'tcx>>, variant_index: VariantIdx }, |
| |
| /// 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), |
| |
| /// Executes a piece of inline Assembly. Stored in a Box to keep the size |
| /// of `StatementKind` low. |
| InlineAsm(Box<InlineAsm<'tcx>>), |
| |
| /// Retag references in the given place, ensuring they got fresh tags. This is |
| /// part of the Stacked Borrows model. These statements are currently only interpreted |
| /// by miri and only generated when "-Z mir-emit-retag" is passed. |
| /// See <https://internals.rust-lang.org/t/stacked-borrows-an-aliasing-model-for-rust/8153/> |
| /// for more details. |
| Retag(RetagKind, Box<Place<'tcx>>), |
| |
| /// Encodes a user's type ascription. These need to be preserved |
| /// intact so that NLL can respect them. For example: |
| /// |
| /// let a: T = y; |
| /// |
| /// The effect of this annotation is to relate the type `T_y` of the place `y` |
| /// to the user-given type `T`. The effect depends on the specified variance: |
| /// |
| /// - `Covariant` -- requires that `T_y <: T` |
| /// - `Contravariant` -- requires that `T_y :> T` |
| /// - `Invariant` -- requires that `T_y == T` |
| /// - `Bivariant` -- no effect |
| AscribeUserType(Box<(Place<'tcx>, UserTypeProjection)>, ty::Variance), |
| |
| /// No-op. Useful for deleting instructions without affecting statement indices. |
| Nop, |
| } |
| |
| /// Describes what kind of retag is to be performed. |
| #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq, HashStable)] |
| pub enum RetagKind { |
| /// The initial retag when entering a function. |
| FnEntry, |
| /// Retag preparing for a two-phase borrow. |
| TwoPhase, |
| /// Retagging raw pointers. |
| Raw, |
| /// A "normal" retag. |
| Default, |
| } |
| |
| /// The `FakeReadCause` describes the type of pattern why a FakeRead statement exists. |
| #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, HashStable)] |
| pub enum FakeReadCause { |
| /// Inject a fake read of the borrowed input at the end of each guards |
| /// code. |
| /// |
| /// This should ensure that you cannot change the variant for an enum while |
| /// you are in the midst of matching on it. |
| ForMatchGuard, |
| |
| /// `let x: !; match x {}` doesn't generate any read of x so we need to |
| /// generate a read of x to check that it is initialized and safe. |
| ForMatchedPlace, |
| |
| /// A fake read of the RefWithinGuard version of a bind-by-value variable |
| /// in a match guard to ensure that it's value hasn't change by the time |
| /// we create the OutsideGuard version. |
| ForGuardBinding, |
| |
| /// Officially, the semantics of |
| /// |
| /// `let pattern = <expr>;` |
| /// |
| /// is that `<expr>` is evaluated into a temporary and then this temporary is |
| /// into the pattern. |
| /// |
| /// However, if we see the simple pattern `let var = <expr>`, we optimize this to |
| /// evaluate `<expr>` directly into the variable `var`. This is mostly unobservable, |
| /// but in some cases it can affect the borrow checker, as in #53695. |
| /// Therefore, we insert a "fake read" here to ensure that we get |
| /// appropriate errors. |
| ForLet, |
| } |
| |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct InlineAsm<'tcx> { |
| pub asm: HirInlineAsm, |
| pub outputs: Box<[Place<'tcx>]>, |
| pub inputs: Box<[(Span, Operand<'tcx>)]>, |
| } |
| |
| impl Debug for Statement<'_> { |
| fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { |
| use self::StatementKind::*; |
| match self.kind { |
| Assign(box(ref place, ref rv)) => write!(fmt, "{:?} = {:?}", place, rv), |
| FakeRead(ref cause, ref place) => write!(fmt, "FakeRead({:?}, {:?})", cause, place), |
| Retag(ref kind, ref place) => write!( |
| fmt, |
| "Retag({}{:?})", |
| match kind { |
| RetagKind::FnEntry => "[fn entry] ", |
| RetagKind::TwoPhase => "[2phase] ", |
| RetagKind::Raw => "[raw] ", |
| RetagKind::Default => "", |
| }, |
| place, |
| ), |
| 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) => { |
| write!(fmt, "asm!({:?} : {:?} : {:?})", asm.asm, asm.outputs, asm.inputs) |
| } |
| AscribeUserType(box(ref place, ref c_ty), ref variance) => { |
| write!(fmt, "AscribeUserType({:?}, {:?}, {:?})", place, variance, c_ty) |
| } |
| 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, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, HashStable, |
| )] |
| pub struct Place<'tcx> { |
| pub base: PlaceBase<'tcx>, |
| |
| /// projection out of a place (access a field, deref a pointer, etc) |
| pub projection: Box<[PlaceElem<'tcx>]>, |
| } |
| |
| #[derive( |
| Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, HashStable, |
| )] |
| pub enum PlaceBase<'tcx> { |
| /// local variable |
| Local(Local), |
| |
| /// static or static mut variable |
| Static(Box<Static<'tcx>>), |
| } |
| |
| /// We store the normalized type to avoid requiring normalization when reading MIR |
| #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable)] |
| pub struct Static<'tcx> { |
| pub ty: Ty<'tcx>, |
| pub kind: StaticKind<'tcx>, |
| /// The `DefId` of the item this static was declared in. For promoted values, usually, this is |
| /// the same as the `DefId` of the `mir::Body` containing the `Place` this promoted appears in. |
| /// However, after inlining, that might no longer be the case as inlined `Place`s are copied |
| /// into the calling frame. |
| pub def_id: DefId, |
| } |
| |
| #[derive( |
| Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable, RustcEncodable, RustcDecodable, |
| )] |
| pub enum StaticKind<'tcx> { |
| /// Promoted references consist of an id (`Promoted`) and the substs necessary to monomorphize |
| /// it. Usually, these substs are just the identity substs for the item. However, the inliner |
| /// will adjust these substs when it inlines a function based on the substs at the callsite. |
| Promoted(Promoted, SubstsRef<'tcx>), |
| Static, |
| } |
| |
| impl_stable_hash_for!(struct Static<'tcx> { |
| ty, |
| kind, |
| def_id |
| }); |
| |
| #[derive( |
| Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, HashStable, |
| )] |
| pub enum ProjectionElem<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. |
| /// |
| /// The included Symbol is the name of the variant, used for printing MIR. |
| Downcast(Option<Symbol>, VariantIdx), |
| } |
| |
| impl<V, T> ProjectionElem<V, T> { |
| /// Returns `true` if the target of this projection may refer to a different region of memory |
| /// than the base. |
| fn is_indirect(&self) -> bool { |
| match self { |
| Self::Deref => true, |
| |
| | Self::Field(_, _) |
| | Self::Index(_) |
| | Self::ConstantIndex { .. } |
| | Self::Subslice { .. } |
| | Self::Downcast(_, _) |
| => false |
| } |
| } |
| } |
| |
| /// 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<Local, Ty<'tcx>>; |
| |
| // At least on 64 bit systems, `PlaceElem` should not be larger than two pointers. |
| #[cfg(target_arch = "x86_64")] |
| static_assert_size!(PlaceElem<'_>, 16); |
| |
| /// Alias for projections as they appear in `UserTypeProjection`, where we |
| /// need neither the `V` parameter for `Index` nor the `T` for `Field`. |
| pub type ProjectionKind = ProjectionElem<(), ()>; |
| |
| newtype_index! { |
| pub struct Field { |
| derive [HashStable] |
| DEBUG_FORMAT = "field[{}]" |
| } |
| } |
| |
| #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub struct PlaceRef<'a, 'tcx> { |
| pub base: &'a PlaceBase<'tcx>, |
| pub projection: &'a [PlaceElem<'tcx>], |
| } |
| |
| impl<'tcx> Place<'tcx> { |
| // FIXME change this back to a const when projection is a shared slice. |
| // |
| // pub const RETURN_PLACE: Place<'tcx> = Place { |
| // base: PlaceBase::Local(RETURN_PLACE), |
| // projection: &[], |
| // }; |
| pub fn return_place() -> Place<'tcx> { |
| Place { |
| base: PlaceBase::Local(RETURN_PLACE), |
| projection: Box::new([]), |
| } |
| } |
| |
| 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: VariantIdx) -> Place<'tcx> { |
| self.elem(ProjectionElem::Downcast( |
| Some(adt_def.variants[variant_index].ident.name), |
| variant_index, |
| )) |
| } |
| |
| pub fn downcast_unnamed(self, variant_index: VariantIdx) -> Place<'tcx> { |
| self.elem(ProjectionElem::Downcast(None, variant_index)) |
| } |
| |
| pub fn index(self, index: Local) -> Place<'tcx> { |
| self.elem(ProjectionElem::Index(index)) |
| } |
| |
| pub fn elem(self, elem: PlaceElem<'tcx>) -> Place<'tcx> { |
| // FIXME(spastorino): revisit this again once projection is not a Box<[T]> anymore |
| let mut projection = self.projection.into_vec(); |
| projection.push(elem); |
| |
| Place { |
| base: self.base, |
| projection: projection.into_boxed_slice(), |
| } |
| } |
| |
| /// Returns `true` if this `Place` contains a `Deref` projection. |
| /// |
| /// If `Place::is_indirect` returns false, the caller knows that the `Place` refers to the |
| /// same region of memory as its base. |
| pub fn is_indirect(&self) -> bool { |
| self.projection.iter().any(|elem| elem.is_indirect()) |
| } |
| |
| /// Finds the innermost `Local` from this `Place`, *if* it is either a local itself or |
| /// a single deref of a local. |
| // |
| // FIXME: can we safely swap the semantics of `fn base_local` below in here instead? |
| pub fn local_or_deref_local(&self) -> Option<Local> { |
| match self { |
| Place { |
| base: PlaceBase::Local(local), |
| projection: box [], |
| } | |
| Place { |
| base: PlaceBase::Local(local), |
| projection: box [ProjectionElem::Deref], |
| } => Some(*local), |
| _ => None, |
| } |
| } |
| |
| pub fn as_ref(&self) -> PlaceRef<'_, 'tcx> { |
| PlaceRef { |
| base: &self.base, |
| projection: &self.projection, |
| } |
| } |
| } |
| |
| impl From<Local> for Place<'_> { |
| fn from(local: Local) -> Self { |
| Place { |
| base: local.into(), |
| projection: Box::new([]), |
| } |
| } |
| } |
| |
| impl From<Local> for PlaceBase<'_> { |
| fn from(local: Local) -> Self { |
| PlaceBase::Local(local) |
| } |
| } |
| |
| impl<'a, 'tcx> PlaceRef<'a, 'tcx> { |
| /// Finds the innermost `Local` from this `Place`, *if* it is either a local itself or |
| /// a single deref of a local. |
| // |
| // FIXME: can we safely swap the semantics of `fn base_local` below in here instead? |
| pub fn local_or_deref_local(&self) -> Option<Local> { |
| match self { |
| PlaceRef { |
| base: PlaceBase::Local(local), |
| projection: [], |
| } | |
| PlaceRef { |
| base: PlaceBase::Local(local), |
| projection: [ProjectionElem::Deref], |
| } => Some(*local), |
| _ => None, |
| } |
| } |
| } |
| |
| impl Debug for Place<'_> { |
| fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { |
| for elem in self.projection.iter().rev() { |
| match elem { |
| ProjectionElem::Downcast(_, _) | ProjectionElem::Field(_, _) => { |
| write!(fmt, "(").unwrap(); |
| } |
| ProjectionElem::Deref => { |
| write!(fmt, "(*").unwrap(); |
| } |
| ProjectionElem::Index(_) |
| | ProjectionElem::ConstantIndex { .. } |
| | ProjectionElem::Subslice { .. } => {} |
| } |
| } |
| |
| write!(fmt, "{:?}", self.base)?; |
| |
| for elem in self.projection.iter() { |
| match elem { |
| ProjectionElem::Downcast(Some(name), _index) => { |
| write!(fmt, " as {})", name)?; |
| } |
| ProjectionElem::Downcast(None, index) => { |
| write!(fmt, " as variant#{:?})", index)?; |
| } |
| ProjectionElem::Deref => { |
| write!(fmt, ")")?; |
| } |
| ProjectionElem::Field(field, ty) => { |
| write!(fmt, ".{:?}: {:?})", field.index(), ty)?; |
| } |
| ProjectionElem::Index(ref index) => { |
| write!(fmt, "[{:?}]", index)?; |
| } |
| ProjectionElem::ConstantIndex { offset, min_length, from_end: false } => { |
| write!(fmt, "[{:?} of {:?}]", offset, min_length)?; |
| } |
| ProjectionElem::ConstantIndex { offset, min_length, from_end: true } => { |
| write!(fmt, "[-{:?} of {:?}]", offset, min_length)?; |
| } |
| ProjectionElem::Subslice { from, to } if *to == 0 => { |
| write!(fmt, "[{:?}:]", from)?; |
| } |
| ProjectionElem::Subslice { from, to } if *from == 0 => { |
| write!(fmt, "[:-{:?}]", to)?; |
| } |
| ProjectionElem::Subslice { from, to } => { |
| write!(fmt, "[{:?}:-{:?}]", from, to)?; |
| } |
| } |
| } |
| |
| Ok(()) |
| } |
| } |
| |
| impl Debug for PlaceBase<'_> { |
| fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { |
| match *self { |
| PlaceBase::Local(id) => write!(fmt, "{:?}", id), |
| PlaceBase::Static(box self::Static { ty, kind: StaticKind::Static, def_id }) => { |
| write!(fmt, "({}: {:?})", ty::tls::with(|tcx| tcx.def_path_str(def_id)), ty) |
| } |
| PlaceBase::Static(box self::Static { |
| ty, kind: StaticKind::Promoted(promoted, _), def_id: _ |
| }) => { |
| write!(fmt, "({:?}: {:?})", promoted, ty) |
| } |
| } |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Scopes |
| |
| newtype_index! { |
| pub struct SourceScope { |
| derive [HashStable] |
| DEBUG_FORMAT = "scope[{}]", |
| const OUTERMOST_SOURCE_SCOPE = 0, |
| } |
| } |
| |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct SourceScopeData { |
| pub span: Span, |
| pub parent_scope: Option<SourceScope>, |
| } |
| |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct SourceScopeLocalData { |
| /// An `HirId` with lint levels equivalent to this scope's lint levels. |
| pub lint_root: hir::HirId, |
| /// The unsafe block that contains this node. |
| pub safety: Safety, |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Operands |
| |
| /// These are values that can appear inside an rvalue. They are intentionally |
| /// limited to prevent rvalues from being nested in one another. |
| #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, HashStable)] |
| 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>), |
| |
| /// Synthesizes a constant value. |
| Constant(Box<Constant<'tcx>>), |
| } |
| |
| 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> { |
| /// Convenience helper to make a constant that refers to the fn |
| /// with given `DefId` and substs. Since this is used to synthesize |
| /// MIR, assumes `user_ty` is None. |
| pub fn function_handle( |
| tcx: TyCtxt<'tcx>, |
| def_id: DefId, |
| substs: SubstsRef<'tcx>, |
| span: Span, |
| ) -> Self { |
| let ty = tcx.type_of(def_id).subst(tcx, substs); |
| Operand::Constant(box Constant { |
| span, |
| user_ty: None, |
| literal: 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, HashStable)] |
| 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>), |
| |
| /// Creates 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<AggregateKind<'tcx>>, Vec<Operand<'tcx>>), |
| } |
| |
| #[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, HashStable)] |
| pub enum CastKind { |
| Misc, |
| Pointer(PointerCast), |
| } |
| |
| #[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, HashStable)] |
| 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, VariantIdx, SubstsRef<'tcx>, Option<UserTypeAnnotationIndex>, Option<usize>), |
| |
| Closure(DefId, ClosureSubsts<'tcx>), |
| Generator(DefId, GeneratorSubsts<'tcx>, hir::GeneratorMovability), |
| } |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, HashStable)] |
| 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, HashStable)] |
| pub enum NullOp { |
| /// Returns the size of a value of that type |
| SizeOf, |
| /// Creates a new uninitialized box for a value of that type |
| Box, |
| } |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, HashStable)] |
| 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::Shallow => "shallow ", |
| BorrowKind::Mut { .. } | BorrowKind::Unique => "mut ", |
| }; |
| |
| // When printing regions, add trailing space if necessary. |
| let print_region = ty::tls::with(|tcx| { |
| tcx.sess.verbose() || tcx.sess.opts.debugging_opts.identify_regions |
| }); |
| let region = if print_region { |
| let mut region = region.to_string(); |
| if region.len() > 0 { |
| region.push(' '); |
| } |
| region |
| } else { |
| // Do not even print 'static |
| String::new() |
| }; |
| 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, _user_ty, _) => { |
| let variant_def = &adt_def.variants[variant]; |
| |
| let f = &mut *fmt; |
| ty::tls::with(|tcx| { |
| let substs = tcx.lift(&substs).expect("could not lift for printing"); |
| FmtPrinter::new(tcx, f, Namespace::ValueNS) |
| .print_def_path(variant_def.def_id, substs)?; |
| Ok(()) |
| })?; |
| |
| 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(hir_id) = tcx.hir().as_local_hir_id(def_id) { |
| let name = if tcx.sess.opts.debugging_opts.span_free_formats { |
| format!("[closure@{:?}]", hir_id) |
| } else { |
| format!("[closure@{:?}]", tcx.hir().span(hir_id)) |
| }; |
| let mut struct_fmt = fmt.debug_struct(&name); |
| |
| if let Some(upvars) = tcx.upvars(def_id) { |
| for (&var_id, place) in upvars.keys().zip(places) { |
| let var_name = tcx.hir().name(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(hir_id) = tcx.hir().as_local_hir_id(def_id) { |
| let name = format!("[generator@{:?}]", tcx.hir().span(hir_id)); |
| let mut struct_fmt = fmt.debug_struct(&name); |
| |
| if let Some(upvars) = tcx.upvars(def_id) { |
| for (&var_id, place) in upvars.keys().zip(places) { |
| let var_name = tcx.hir().name(var_id); |
| struct_fmt.field(&var_name.as_str(), place); |
| } |
| } |
| |
| 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(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct Constant<'tcx> { |
| pub span: Span, |
| |
| /// Optional user-given type: for something like |
| /// `collect::<Vec<_>>`, this would be present and would |
| /// indicate that `Vec<_>` was explicitly specified. |
| /// |
| /// Needed for NLL to impose user-given type constraints. |
| pub user_ty: Option<UserTypeAnnotationIndex>, |
| |
| pub literal: &'tcx ty::Const<'tcx>, |
| } |
| |
| /// A collection of projections into user types. |
| /// |
| /// They are projections because a binding can occur a part of a |
| /// parent pattern that has been ascribed a type. |
| /// |
| /// Its a collection because there can be multiple type ascriptions on |
| /// the path from the root of the pattern down to the binding itself. |
| /// |
| /// An example: |
| /// |
| /// ```rust |
| /// struct S<'a>((i32, &'a str), String); |
| /// let S((_, w): (i32, &'static str), _): S = ...; |
| /// // ------ ^^^^^^^^^^^^^^^^^^^ (1) |
| /// // --------------------------------- ^ (2) |
| /// ``` |
| /// |
| /// The highlights labelled `(1)` show the subpattern `(_, w)` being |
| /// ascribed the type `(i32, &'static str)`. |
| /// |
| /// The highlights labelled `(2)` show the whole pattern being |
| /// ascribed the type `S`. |
| /// |
| /// In this example, when we descend to `w`, we will have built up the |
| /// following two projected types: |
| /// |
| /// * base: `S`, projection: `(base.0).1` |
| /// * base: `(i32, &'static str)`, projection: `base.1` |
| /// |
| /// The first will lead to the constraint `w: &'1 str` (for some |
| /// inferred region `'1`). The second will lead to the constraint `w: |
| /// &'static str`. |
| #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct UserTypeProjections { |
| pub(crate) contents: Vec<(UserTypeProjection, Span)>, |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for UserTypeProjections { |
| contents |
| } |
| } |
| |
| impl<'tcx> UserTypeProjections { |
| pub fn none() -> Self { |
| UserTypeProjections { contents: vec![] } |
| } |
| |
| pub fn from_projections(projs: impl Iterator<Item = (UserTypeProjection, Span)>) -> Self { |
| UserTypeProjections { contents: projs.collect() } |
| } |
| |
| pub fn projections_and_spans(&self) -> impl Iterator<Item = &(UserTypeProjection, Span)> { |
| self.contents.iter() |
| } |
| |
| pub fn projections(&self) -> impl Iterator<Item = &UserTypeProjection> { |
| self.contents.iter().map(|&(ref user_type, _span)| user_type) |
| } |
| |
| pub fn push_projection(mut self, user_ty: &UserTypeProjection, span: Span) -> Self { |
| self.contents.push((user_ty.clone(), span)); |
| self |
| } |
| |
| fn map_projections( |
| mut self, |
| mut f: impl FnMut(UserTypeProjection) -> UserTypeProjection, |
| ) -> Self { |
| self.contents = self.contents.drain(..).map(|(proj, span)| (f(proj), span)).collect(); |
| self |
| } |
| |
| pub fn index(self) -> Self { |
| self.map_projections(|pat_ty_proj| pat_ty_proj.index()) |
| } |
| |
| pub fn subslice(self, from: u32, to: u32) -> Self { |
| self.map_projections(|pat_ty_proj| pat_ty_proj.subslice(from, to)) |
| } |
| |
| pub fn deref(self) -> Self { |
| self.map_projections(|pat_ty_proj| pat_ty_proj.deref()) |
| } |
| |
| pub fn leaf(self, field: Field) -> Self { |
| self.map_projections(|pat_ty_proj| pat_ty_proj.leaf(field)) |
| } |
| |
| pub fn variant(self, adt_def: &'tcx AdtDef, variant_index: VariantIdx, field: Field) -> Self { |
| self.map_projections(|pat_ty_proj| pat_ty_proj.variant(adt_def, variant_index, field)) |
| } |
| } |
| |
| /// Encodes the effect of a user-supplied type annotation on the |
| /// subcomponents of a pattern. The effect is determined by applying the |
| /// given list of proejctions to some underlying base type. Often, |
| /// the projection element list `projs` is empty, in which case this |
| /// directly encodes a type in `base`. But in the case of complex patterns with |
| /// subpatterns and bindings, we want to apply only a *part* of the type to a variable, |
| /// in which case the `projs` vector is used. |
| /// |
| /// Examples: |
| /// |
| /// * `let x: T = ...` -- here, the `projs` vector is empty. |
| /// |
| /// * `let (x, _): T = ...` -- here, the `projs` vector would contain |
| /// `field[0]` (aka `.0`), indicating that the type of `s` is |
| /// determined by finding the type of the `.0` field from `T`. |
| #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct UserTypeProjection { |
| pub base: UserTypeAnnotationIndex, |
| pub projs: Vec<ProjectionKind>, |
| } |
| |
| impl Copy for ProjectionKind {} |
| |
| impl UserTypeProjection { |
| pub(crate) fn index(mut self) -> Self { |
| self.projs.push(ProjectionElem::Index(())); |
| self |
| } |
| |
| pub(crate) fn subslice(mut self, from: u32, to: u32) -> Self { |
| self.projs.push(ProjectionElem::Subslice { from, to }); |
| self |
| } |
| |
| pub(crate) fn deref(mut self) -> Self { |
| self.projs.push(ProjectionElem::Deref); |
| self |
| } |
| |
| pub(crate) fn leaf(mut self, field: Field) -> Self { |
| self.projs.push(ProjectionElem::Field(field, ())); |
| self |
| } |
| |
| pub(crate) fn variant( |
| mut self, |
| adt_def: &'tcx AdtDef, |
| variant_index: VariantIdx, |
| field: Field, |
| ) -> Self { |
| self.projs.push(ProjectionElem::Downcast( |
| Some(adt_def.variants[variant_index].ident.name), |
| variant_index, |
| )); |
| self.projs.push(ProjectionElem::Field(field, ())); |
| self |
| } |
| } |
| |
| CloneTypeFoldableAndLiftImpls! { ProjectionKind, } |
| |
| impl<'tcx> TypeFoldable<'tcx> for UserTypeProjection { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| use crate::mir::ProjectionElem::*; |
| |
| let base = self.base.fold_with(folder); |
| let projs: Vec<_> = self |
| .projs |
| .iter() |
| .map(|elem| match elem { |
| Deref => Deref, |
| Field(f, ()) => Field(f.clone(), ()), |
| Index(()) => Index(()), |
| elem => elem.clone(), |
| }) |
| .collect(); |
| |
| UserTypeProjection { base, projs } |
| } |
| |
| fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool { |
| self.base.visit_with(visitor) |
| // Note: there's nothing in `self.proj` to visit. |
| } |
| } |
| |
| newtype_index! { |
| pub struct Promoted { |
| derive [HashStable] |
| DEBUG_FORMAT = "promoted[{}]" |
| } |
| } |
| |
| impl<'tcx> Debug for Constant<'tcx> { |
| fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { |
| write!(fmt, "{}", self) |
| } |
| } |
| |
| impl<'tcx> Display for Constant<'tcx> { |
| fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result { |
| write!(fmt, "const ")?; |
| write!(fmt, "{}", self.literal) |
| } |
| } |
| |
| impl<'tcx> graph::DirectedGraph for Body<'tcx> { |
| type Node = BasicBlock; |
| } |
| |
| impl<'tcx> graph::WithNumNodes for Body<'tcx> { |
| fn num_nodes(&self) -> usize { |
| self.basic_blocks.len() |
| } |
| } |
| |
| impl<'tcx> graph::WithStartNode for Body<'tcx> { |
| fn start_node(&self) -> Self::Node { |
| START_BLOCK |
| } |
| } |
| |
| impl<'tcx> graph::WithPredecessors for Body<'tcx> { |
| fn predecessors( |
| &self, |
| node: Self::Node, |
| ) -> <Self as GraphPredecessors<'_>>::Iter { |
| self.predecessors_for(node).clone().into_iter() |
| } |
| } |
| |
| impl<'tcx> graph::WithSuccessors for Body<'tcx> { |
| fn successors( |
| &self, |
| node: Self::Node, |
| ) -> <Self as GraphSuccessors<'_>>::Iter { |
| self.basic_blocks[node].terminator().successors().cloned() |
| } |
| } |
| |
| impl<'a, 'b> graph::GraphPredecessors<'b> for Body<'a> { |
| type Item = BasicBlock; |
| type Iter = IntoIter<BasicBlock>; |
| } |
| |
| impl<'a, 'b> graph::GraphSuccessors<'b> for Body<'a> { |
| type Item = BasicBlock; |
| type Iter = iter::Cloned<Successors<'b>>; |
| } |
| |
| #[derive(Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd, HashStable)] |
| pub struct Location { |
| /// The block that the location is within. |
| pub block: BasicBlock, |
| |
| /// The location is the position of the start of the statement; or, if |
| /// `statement_index` equals the number of 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 } |
| } |
| |
| /// Returns `true` if `other` is earlier in the control flow graph than `self`. |
| pub fn is_predecessor_of<'tcx>(&self, other: Location, body: &Body<'tcx>) -> bool { |
| // If we are in the same block as the other location and are an earlier statement |
| // then we are a predecessor of `other`. |
| if self.block == other.block && self.statement_index < other.statement_index { |
| return true; |
| } |
| |
| // If we're in another block, then we want to check that block is a predecessor of `other`. |
| let mut queue: Vec<BasicBlock> = body.predecessors_for(other.block).clone(); |
| let mut visited = FxHashSet::default(); |
| |
| while let Some(block) = queue.pop() { |
| // If we haven't visited this block before, then make sure we visit it's predecessors. |
| if visited.insert(block) { |
| queue.append(&mut body.predecessors_for(block).clone()); |
| } else { |
| continue; |
| } |
| |
| // If we found the block that `self` is in, then we are a predecessor of `other` (since |
| // we found that block by looking at the predecessors of `other`). |
| if self.block == block { |
| return true; |
| } |
| } |
| |
| false |
| } |
| |
| pub fn dominates(&self, other: Location, dominators: &Dominators<BasicBlock>) -> 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, HashStable)] |
| pub enum UnsafetyViolationKind { |
| General, |
| /// Permitted both in `const fn`s and regular `fn`s. |
| GeneralAndConstFn, |
| ExternStatic(hir::HirId), |
| BorrowPacked(hir::HirId), |
| } |
| |
| #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct UnsafetyViolation { |
| pub source_info: SourceInfo, |
| pub description: InternedString, |
| pub details: InternedString, |
| pub kind: UnsafetyViolationKind, |
| } |
| |
| #[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)] |
| 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<[(hir::HirId, bool)]>, |
| } |
| |
| newtype_index! { |
| pub struct GeneratorSavedLocal { |
| derive [HashStable] |
| DEBUG_FORMAT = "_{}", |
| } |
| } |
| |
| /// The layout of generator state. |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct GeneratorLayout<'tcx> { |
| /// The type of every local stored inside the generator. |
| pub field_tys: IndexVec<GeneratorSavedLocal, Ty<'tcx>>, |
| |
| /// Which of the above fields are in each variant. Note that one field may |
| /// be stored in multiple variants. |
| pub variant_fields: IndexVec<VariantIdx, IndexVec<Field, GeneratorSavedLocal>>, |
| |
| /// Which saved locals are storage-live at the same time. Locals that do not |
| /// have conflicts with each other are allowed to overlap in the computed |
| /// layout. |
| pub storage_conflicts: BitMatrix<GeneratorSavedLocal, GeneratorSavedLocal>, |
| |
| /// The names and scopes of all the stored generator locals. |
| /// |
| /// N.B., this is *strictly* a temporary hack for codegen |
| /// debuginfo generation, and will be removed at some point. |
| /// Do **NOT** use it for anything else, local information should not be |
| /// in the MIR, please rely on local crate HIR or other side-channels. |
| // |
| // FIXME(tmandry): see above. |
| pub __local_debuginfo_codegen_only_do_not_use: IndexVec<GeneratorSavedLocal, LocalDecl<'tcx>>, |
| } |
| |
| #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| pub struct BorrowCheckResult<'tcx> { |
| pub closure_requirements: Option<ClosureRegionRequirements<'tcx>>, |
| 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, HashStable)] |
| pub struct ClosureRegionRequirements<'tcx> { |
| /// 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<ClosureOutlivesRequirement<'tcx>>, |
| } |
| |
| /// Indicates an outlives-constraint between a type or between two |
| /// free regions declared on the closure. |
| #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| 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, |
| |
| // ... due to this reason. |
| pub category: ConstraintCategory, |
| } |
| |
| /// Outlives-constraints can be categorized to determine whether and why they |
| /// are interesting (for error reporting). Order of variants indicates sort |
| /// order of the category, thereby influencing diagnostic output. |
| /// |
| /// See also [rustc_mir::borrow_check::nll::constraints]. |
| #[derive( |
| Copy, |
| Clone, |
| Debug, |
| Eq, |
| PartialEq, |
| PartialOrd, |
| Ord, |
| Hash, |
| RustcEncodable, |
| RustcDecodable, |
| HashStable, |
| )] |
| pub enum ConstraintCategory { |
| Return, |
| Yield, |
| UseAsConst, |
| UseAsStatic, |
| TypeAnnotation, |
| Cast, |
| |
| /// A constraint that came from checking the body of a closure. |
| /// |
| /// We try to get the category that the closure used when reporting this. |
| ClosureBounds, |
| CallArgument, |
| CopyBound, |
| SizedBound, |
| Assignment, |
| OpaqueType, |
| |
| /// A "boring" constraint (caused by the given location) is one that |
| /// the user probably doesn't want to see described in diagnostics, |
| /// because it is kind of an artifact of the type system setup. |
| /// Example: `x = Foo { field: y }` technically creates |
| /// intermediate regions representing the "type of `Foo { field: y |
| /// }`", and data flows from `y` into those variables, but they |
| /// are not very interesting. The assignment into `x` on the other |
| /// hand might be. |
| Boring, |
| // Boring and applicable everywhere. |
| BoringNoLocation, |
| |
| /// A constraint that doesn't correspond to anything the user sees. |
| Internal, |
| } |
| |
| /// The subject of a `ClosureOutlivesRequirement` -- that is, the thing |
| /// that must outlive some region. |
| #[derive(Copy, Clone, Debug, RustcEncodable, RustcDecodable, HashStable)] |
| 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! { |
| BlockTailInfo, |
| MirPhase, |
| Mutability, |
| SourceInfo, |
| UpvarDebuginfo, |
| FakeReadCause, |
| RetagKind, |
| SourceScope, |
| SourceScopeData, |
| SourceScopeLocalData, |
| UserTypeAnnotationIndex, |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for Body<'tcx> { |
| phase, |
| basic_blocks, |
| source_scopes, |
| source_scope_local_data, |
| yield_ty, |
| generator_drop, |
| generator_layout, |
| local_decls, |
| user_type_annotations, |
| arg_count, |
| __upvar_debuginfo_codegen_only_do_not_use, |
| spread_arg, |
| control_flow_destroyed, |
| span, |
| cache, |
| } |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for GeneratorLayout<'tcx> { |
| field_tys, |
| variant_fields, |
| storage_conflicts, |
| __local_debuginfo_codegen_only_do_not_use, |
| } |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for LocalDecl<'tcx> { |
| mutability, |
| is_user_variable, |
| internal, |
| ty, |
| user_ty, |
| name, |
| source_info, |
| is_block_tail, |
| visibility_scope, |
| } |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for BasicBlockData<'tcx> { |
| statements, |
| terminator, |
| is_cleanup, |
| } |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for Statement<'tcx> { |
| source_info, kind |
| } |
| } |
| |
| EnumTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for StatementKind<'tcx> { |
| (StatementKind::Assign)(a), |
| (StatementKind::FakeRead)(cause, place), |
| (StatementKind::SetDiscriminant) { place, variant_index }, |
| (StatementKind::StorageLive)(a), |
| (StatementKind::StorageDead)(a), |
| (StatementKind::InlineAsm)(a), |
| (StatementKind::Retag)(kind, place), |
| (StatementKind::AscribeUserType)(a, v), |
| (StatementKind::Nop), |
| } |
| } |
| |
| BraceStructTypeFoldableImpl! { |
| impl<'tcx> TypeFoldable<'tcx> for InlineAsm<'tcx> { |
| asm, |
| outputs, |
| inputs, |
| } |
| } |
| |
| EnumTypeFoldableImpl! { |
| impl<'tcx, T> TypeFoldable<'tcx> for ClearCrossCrate<T> { |
| (ClearCrossCrate::Clear), |
| (ClearCrossCrate::Set)(a), |
| } where T: TypeFoldable<'tcx> |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| use crate::mir::TerminatorKind::*; |
| |
| let kind = match self.kind { |
| Goto { target } => Goto { 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, from_hir_call } => { |
| 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, |
| from_hir_call, |
| } |
| } |
| Assert { ref cond, expected, ref msg, target, cleanup } => { |
| use PanicInfo::*; |
| let msg = match msg { |
| BoundsCheck { ref len, ref index } => |
| BoundsCheck { |
| len: len.fold_with(folder), |
| index: index.fold_with(folder), |
| }, |
| Panic { .. } | Overflow(_) | OverflowNeg | DivisionByZero | RemainderByZero | |
| GeneratorResumedAfterReturn | GeneratorResumedAfterPanic => |
| 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, imaginary_target } => { |
| FalseEdges { real_target, imaginary_target } |
| } |
| FalseUnwind { real_target, unwind } => FalseUnwind { real_target, unwind }, |
| }; |
| Terminator { source_info: self.source_info, kind } |
| } |
| |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| use crate::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) { |
| use PanicInfo::*; |
| match msg { |
| BoundsCheck { ref len, ref index } => |
| len.visit_with(visitor) || index.visit_with(visitor), |
| Panic { .. } | Overflow(_) | OverflowNeg | |
| DivisionByZero | RemainderByZero | |
| GeneratorResumedAfterReturn | GeneratorResumedAfterPanic => |
| false |
| } |
| } else { |
| false |
| } |
| } |
| Goto { .. } |
| | Resume |
| | Abort |
| | Return |
| | GeneratorDrop |
| | Unreachable |
| | FalseEdges { .. } |
| | FalseUnwind { .. } => false, |
| } |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Place<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| Place { |
| base: self.base.fold_with(folder), |
| projection: self.projection.fold_with(folder), |
| } |
| } |
| |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| self.base.visit_with(visitor) || self.projection.visit_with(visitor) |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for PlaceBase<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| match self { |
| PlaceBase::Local(local) => PlaceBase::Local(local.fold_with(folder)), |
| PlaceBase::Static(static_) => PlaceBase::Static(static_.fold_with(folder)), |
| } |
| } |
| |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| match self { |
| PlaceBase::Local(local) => local.visit_with(visitor), |
| PlaceBase::Static(static_) => (**static_).visit_with(visitor), |
| } |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Static<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| Static { |
| ty: self.ty.fold_with(folder), |
| kind: self.kind.fold_with(folder), |
| def_id: self.def_id, |
| } |
| } |
| |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| let Static { ty, kind, def_id: _ } = self; |
| |
| ty.visit_with(visitor) || kind.visit_with(visitor) |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for StaticKind<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| match self { |
| StaticKind::Promoted(promoted, substs) => |
| StaticKind::Promoted(promoted.fold_with(folder), substs.fold_with(folder)), |
| StaticKind::Static => StaticKind::Static |
| } |
| } |
| |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| match self { |
| StaticKind::Promoted(promoted, substs) => |
| promoted.visit_with(visitor) || substs.visit_with(visitor), |
| StaticKind::Static => { false } |
| } |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| use crate::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, user_ty, n) => AggregateKind::Adt( |
| def, |
| v, |
| substs.fold_with(folder), |
| user_ty.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<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| use crate::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, user_ty, _) => { |
| substs.visit_with(visitor) || user_ty.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<F: TypeFolder<'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<V: TypeVisitor<'tcx>>(&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> TypeFoldable<'tcx> for PlaceElem<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| use crate::mir::ProjectionElem::*; |
| |
| match self { |
| Deref => Deref, |
| Field(f, ty) => Field(*f, ty.fold_with(folder)), |
| Index(v) => Index(v.fold_with(folder)), |
| elem => elem.clone(), |
| } |
| } |
| |
| fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool { |
| use crate::mir::ProjectionElem::*; |
| |
| match self { |
| Field(_, ty) => ty.visit_with(visitor), |
| Index(v) => v.visit_with(visitor), |
| _ => false, |
| } |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Field { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self { |
| *self |
| } |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool { |
| false |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for GeneratorSavedLocal { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self { |
| *self |
| } |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool { |
| false |
| } |
| } |
| |
| impl<'tcx, R: Idx, C: Idx> TypeFoldable<'tcx> for BitMatrix<R, C> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self { |
| self.clone() |
| } |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool { |
| false |
| } |
| } |
| |
| impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> { |
| fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self { |
| Constant { |
| span: self.span.clone(), |
| user_ty: self.user_ty.fold_with(folder), |
| literal: self.literal.fold_with(folder), |
| } |
| } |
| fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool { |
| self.literal.visit_with(visitor) |
| } |
| } |