942 lines
32 KiB
Rust
942 lines
32 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use graphviz::IntoCow;
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use middle::const_eval::ConstVal;
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use rustc_const_eval::{ConstUsize, ConstInt};
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use middle::def_id::DefId;
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use middle::subst::Substs;
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use middle::ty::{self, AdtDef, ClosureSubsts, FnOutput, Region, Ty};
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use util::ppaux;
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use rustc_back::slice;
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use rustc_front::hir::InlineAsm;
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use std::ascii;
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use std::borrow::{Cow};
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use std::fmt::{self, Debug, Formatter, Write};
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use std::{iter, u32};
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use std::ops::{Index, IndexMut};
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use syntax::ast::{self, Name};
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use syntax::codemap::Span;
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/// Lowered representation of a single function.
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#[derive(Clone, RustcEncodable, RustcDecodable)]
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pub struct Mir<'tcx> {
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/// List of basic blocks. References to basic block use a newtyped index type `BasicBlock`
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/// that indexes into this vector.
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pub basic_blocks: Vec<BasicBlockData<'tcx>>,
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/// Return type of the function.
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pub return_ty: FnOutput<'tcx>,
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/// Variables: these are stack slots corresponding to user variables. They may be
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/// assigned many times.
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pub var_decls: Vec<VarDecl<'tcx>>,
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/// Args: these are stack slots corresponding to the input arguments.
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pub arg_decls: Vec<ArgDecl<'tcx>>,
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/// Temp declarations: stack slots that for temporaries created by
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/// the compiler. These are assigned once, but they are not SSA
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/// values in that it is possible to borrow them and mutate them
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/// through the resulting reference.
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pub temp_decls: Vec<TempDecl<'tcx>>,
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/// A span representing this MIR, for error reporting
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pub span: Span,
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}
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/// where execution begins
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pub const START_BLOCK: BasicBlock = BasicBlock(0);
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/// where execution ends, on normal return
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pub const END_BLOCK: BasicBlock = BasicBlock(1);
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impl<'tcx> Mir<'tcx> {
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pub fn all_basic_blocks(&self) -> Vec<BasicBlock> {
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(0..self.basic_blocks.len())
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.map(|i| BasicBlock::new(i))
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.collect()
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}
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pub fn basic_block_data(&self, bb: BasicBlock) -> &BasicBlockData<'tcx> {
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&self.basic_blocks[bb.index()]
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}
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pub fn basic_block_data_mut(&mut self, bb: BasicBlock) -> &mut BasicBlockData<'tcx> {
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&mut self.basic_blocks[bb.index()]
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}
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}
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impl<'tcx> Index<BasicBlock> for Mir<'tcx> {
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type Output = BasicBlockData<'tcx>;
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#[inline]
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fn index(&self, index: BasicBlock) -> &BasicBlockData<'tcx> {
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self.basic_block_data(index)
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}
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}
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impl<'tcx> IndexMut<BasicBlock> for Mir<'tcx> {
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#[inline]
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fn index_mut(&mut self, index: BasicBlock) -> &mut BasicBlockData<'tcx> {
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self.basic_block_data_mut(index)
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}
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}
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///////////////////////////////////////////////////////////////////////////
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// Mutability and borrow kinds
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#[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
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pub enum Mutability {
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Mut,
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Not,
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}
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#[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
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pub enum BorrowKind {
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/// Data must be immutable and is aliasable.
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Shared,
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/// Data must be immutable but not aliasable. This kind of borrow
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/// cannot currently be expressed by the user and is used only in
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/// implicit closure bindings. It is needed when you the closure
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/// is borrowing or mutating a mutable referent, e.g.:
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///
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/// let x: &mut isize = ...;
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/// let y = || *x += 5;
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///
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/// If we were to try to translate this closure into a more explicit
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/// form, we'd encounter an error with the code as written:
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///
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/// struct Env { x: & &mut isize }
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/// let x: &mut isize = ...;
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/// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
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/// fn fn_ptr(env: &mut Env) { **env.x += 5; }
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///
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/// This is then illegal because you cannot mutate a `&mut` found
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/// in an aliasable location. To solve, you'd have to translate with
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/// an `&mut` borrow:
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///
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/// struct Env { x: & &mut isize }
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/// let x: &mut isize = ...;
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/// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
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/// fn fn_ptr(env: &mut Env) { **env.x += 5; }
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///
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/// Now the assignment to `**env.x` is legal, but creating a
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/// mutable pointer to `x` is not because `x` is not mutable. We
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/// could fix this by declaring `x` as `let mut x`. This is ok in
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/// user code, if awkward, but extra weird for closures, since the
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/// borrow is hidden.
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///
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/// So we introduce a "unique imm" borrow -- the referent is
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/// immutable, but not aliasable. This solves the problem. For
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/// simplicity, we don't give users the way to express this
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/// borrow, it's just used when translating closures.
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Unique,
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/// Data is mutable and not aliasable.
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Mut,
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}
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///////////////////////////////////////////////////////////////////////////
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// Variables and temps
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/// A "variable" is a binding declared by the user as part of the fn
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/// decl, a let, etc.
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#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
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pub struct VarDecl<'tcx> {
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pub mutability: Mutability,
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pub name: Name,
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pub ty: Ty<'tcx>,
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}
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/// A "temp" is a temporary that we place on the stack. They are
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/// anonymous, always mutable, and have only a type.
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#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
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pub struct TempDecl<'tcx> {
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pub ty: Ty<'tcx>,
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}
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/// A "arg" is one of the function's formal arguments. These are
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/// anonymous and distinct from the bindings that the user declares.
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///
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/// For example, in this function:
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///
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/// ```
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/// fn foo((x, y): (i32, u32)) { ... }
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/// ```
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///
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/// there is only one argument, of type `(i32, u32)`, but two bindings
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/// (`x` and `y`).
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#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
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pub struct ArgDecl<'tcx> {
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pub ty: Ty<'tcx>,
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/// If true, this argument is a tuple after monomorphization,
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/// and has to be collected from multiple actual arguments.
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pub spread: bool
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}
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///////////////////////////////////////////////////////////////////////////
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// BasicBlock
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/// The index of a particular basic block. The index is into the `basic_blocks`
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/// list of the `Mir`.
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///
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/// (We use a `u32` internally just to save memory.)
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#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable)]
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pub struct BasicBlock(u32);
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impl BasicBlock {
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pub fn new(index: usize) -> BasicBlock {
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assert!(index < (u32::MAX as usize));
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BasicBlock(index as u32)
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}
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/// Extract the index.
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pub fn index(self) -> usize {
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self.0 as usize
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}
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}
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impl Debug for BasicBlock {
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fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
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write!(fmt, "bb{}", self.0)
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}
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}
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///////////////////////////////////////////////////////////////////////////
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// BasicBlockData and Terminator
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#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
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pub struct BasicBlockData<'tcx> {
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pub statements: Vec<Statement<'tcx>>,
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pub terminator: Option<Terminator<'tcx>>,
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pub is_cleanup: bool,
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}
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#[derive(Clone, RustcEncodable, RustcDecodable)]
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pub enum Terminator<'tcx> {
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/// block should have one successor in the graph; we jump there
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Goto {
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target: BasicBlock,
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},
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/// jump to branch 0 if this lvalue evaluates to true
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If {
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cond: Operand<'tcx>,
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targets: (BasicBlock, BasicBlock),
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},
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/// lvalue evaluates to some enum; jump depending on the branch
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Switch {
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discr: Lvalue<'tcx>,
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adt_def: AdtDef<'tcx>,
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targets: Vec<BasicBlock>,
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},
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/// operand evaluates to an integer; jump depending on its value
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/// to one of the targets, and otherwise fallback to `otherwise`
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SwitchInt {
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/// discriminant value being tested
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discr: Lvalue<'tcx>,
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/// type of value being tested
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switch_ty: Ty<'tcx>,
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/// Possible values. The locations to branch to in each case
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/// are found in the corresponding indices from the `targets` vector.
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values: Vec<ConstVal>,
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/// Possible branch sites. The length of this vector should be
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/// equal to the length of the `values` vector plus 1 -- the
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/// extra item is the block to branch to if none of the values
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/// fit.
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targets: Vec<BasicBlock>,
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},
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/// Indicates that the landing pad is finished and unwinding should
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/// continue. Emitted by build::scope::diverge_cleanup.
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Resume,
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/// Indicates a normal return. The ReturnPointer lvalue should
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/// have been filled in by now. This should only occur in the
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/// `END_BLOCK`.
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Return,
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/// Drop the Lvalue
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Drop {
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value: Lvalue<'tcx>,
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target: BasicBlock,
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unwind: Option<BasicBlock>
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},
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/// Block ends with a call of a converging function
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Call {
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/// The function that’s being called
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func: Operand<'tcx>,
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/// Arguments the function is called with
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args: Vec<Operand<'tcx>>,
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/// Destination for the return value. If some, the call is converging.
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destination: Option<(Lvalue<'tcx>, BasicBlock)>,
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/// Cleanups to be done if the call unwinds.
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cleanup: Option<BasicBlock>
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},
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}
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impl<'tcx> Terminator<'tcx> {
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pub fn successors(&self) -> Cow<[BasicBlock]> {
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use self::Terminator::*;
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match *self {
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Goto { target: ref b } => slice::ref_slice(b).into_cow(),
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If { targets: (b1, b2), .. } => vec![b1, b2].into_cow(),
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Switch { targets: ref b, .. } => b[..].into_cow(),
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SwitchInt { targets: ref b, .. } => b[..].into_cow(),
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Resume => (&[]).into_cow(),
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Return => (&[]).into_cow(),
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Call { destination: Some((_, t)), cleanup: Some(c), .. } => vec![t, c].into_cow(),
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Call { destination: Some((_, ref t)), cleanup: None, .. } =>
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slice::ref_slice(t).into_cow(),
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Call { destination: None, cleanup: Some(ref c), .. } => slice::ref_slice(c).into_cow(),
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Call { destination: None, cleanup: None, .. } => (&[]).into_cow(),
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Drop { target, unwind: Some(unwind), .. } => vec![target, unwind].into_cow(),
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Drop { ref target, .. } => slice::ref_slice(target).into_cow(),
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}
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}
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// FIXME: no mootable cow. I’m honestly not sure what a “cow” between `&mut [BasicBlock]` and
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// `Vec<&mut BasicBlock>` would look like in the first place.
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pub fn successors_mut(&mut self) -> Vec<&mut BasicBlock> {
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use self::Terminator::*;
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match *self {
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Goto { target: ref mut b } => vec![b],
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If { targets: (ref mut b1, ref mut b2), .. } => vec![b1, b2],
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Switch { targets: ref mut b, .. } => b.iter_mut().collect(),
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SwitchInt { targets: ref mut b, .. } => b.iter_mut().collect(),
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Resume => Vec::new(),
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Return => Vec::new(),
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Call { destination: Some((_, ref mut t)), cleanup: Some(ref mut c), .. } => vec![t, c],
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Call { destination: Some((_, ref mut t)), cleanup: None, .. } => vec![t],
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Call { destination: None, cleanup: Some(ref mut c), .. } => vec![c],
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Call { destination: None, cleanup: None, .. } => vec![],
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Drop { ref mut target, unwind: Some(ref mut unwind), .. } => vec![target, unwind],
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Drop { ref mut target, .. } => vec![target]
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}
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}
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}
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impl<'tcx> BasicBlockData<'tcx> {
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pub fn new(terminator: Option<Terminator<'tcx>>) -> BasicBlockData<'tcx> {
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BasicBlockData {
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statements: vec![],
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terminator: terminator,
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is_cleanup: false,
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}
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}
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/// Accessor for terminator.
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///
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/// Terminator may not be None after construction of the basic block is complete. This accessor
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/// provides a convenience way to reach the terminator.
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pub fn terminator(&self) -> &Terminator<'tcx> {
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self.terminator.as_ref().expect("invalid terminator state")
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}
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pub fn terminator_mut(&mut self) -> &mut Terminator<'tcx> {
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self.terminator.as_mut().expect("invalid terminator state")
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}
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}
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impl<'tcx> Debug for Terminator<'tcx> {
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fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
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self.fmt_head(fmt)?;
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let successors = self.successors();
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let labels = self.fmt_successor_labels();
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assert_eq!(successors.len(), labels.len());
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match successors.len() {
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0 => Ok(()),
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1 => write!(fmt, " -> {:?}", successors[0]),
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_ => {
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write!(fmt, " -> [")?;
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for (i, target) in successors.iter().enumerate() {
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if i > 0 {
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write!(fmt, ", ")?;
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}
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write!(fmt, "{}: {:?}", labels[i], target)?;
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}
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write!(fmt, "]")
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}
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}
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}
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}
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impl<'tcx> Terminator<'tcx> {
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/// Write the "head" part of the terminator; that is, its name and the data it uses to pick the
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/// successor basic block, if any. The only information not inlcuded is the list of possible
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/// successors, which may be rendered differently between the text and the graphviz format.
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pub fn fmt_head<W: Write>(&self, fmt: &mut W) -> fmt::Result {
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use self::Terminator::*;
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match *self {
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Goto { .. } => write!(fmt, "goto"),
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If { cond: ref lv, .. } => write!(fmt, "if({:?})", lv),
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Switch { discr: ref lv, .. } => write!(fmt, "switch({:?})", lv),
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SwitchInt { discr: ref lv, .. } => write!(fmt, "switchInt({:?})", lv),
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||
Return => write!(fmt, "return"),
|
||
Resume => write!(fmt, "resume"),
|
||
Drop { ref value, .. } => write!(fmt, "drop({:?})", 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, ", ")?;
|
||
}
|
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write!(fmt, "{:?}", arg)?;
|
||
}
|
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write!(fmt, ")")
|
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}
|
||
}
|
||
}
|
||
|
||
/// Return the list of labels for the edges to the successor basic blocks.
|
||
pub fn fmt_successor_labels(&self) -> Vec<Cow<'static, str>> {
|
||
use self::Terminator::*;
|
||
match *self {
|
||
Return | Resume => vec![],
|
||
Goto { .. } => vec!["".into()],
|
||
If { .. } => vec!["true".into(), "false".into()],
|
||
Switch { ref adt_def, .. } => {
|
||
adt_def.variants
|
||
.iter()
|
||
.map(|variant| variant.name.to_string().into())
|
||
.collect()
|
||
}
|
||
SwitchInt { ref values, .. } => {
|
||
values.iter()
|
||
.map(|const_val| {
|
||
let mut buf = String::new();
|
||
fmt_const_val(&mut buf, const_val).unwrap();
|
||
buf.into()
|
||
})
|
||
.chain(iter::once(String::from("otherwise").into()))
|
||
.collect()
|
||
}
|
||
Call { destination: Some(_), cleanup: Some(_), .. } =>
|
||
vec!["return".into_cow(), "unwind".into_cow()],
|
||
Call { destination: Some(_), cleanup: None, .. } => vec!["return".into_cow()],
|
||
Call { destination: None, cleanup: Some(_), .. } => vec!["unwind".into_cow()],
|
||
Call { destination: None, cleanup: None, .. } => vec![],
|
||
Drop { unwind: None, .. } => vec!["return".into_cow()],
|
||
Drop { .. } => vec!["return".into_cow(), "unwind".into_cow()],
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
///////////////////////////////////////////////////////////////////////////
|
||
// Statements
|
||
|
||
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
||
pub struct Statement<'tcx> {
|
||
pub span: Span,
|
||
pub kind: StatementKind<'tcx>,
|
||
}
|
||
|
||
#[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
|
||
pub enum StatementKind<'tcx> {
|
||
Assign(Lvalue<'tcx>, Rvalue<'tcx>),
|
||
}
|
||
|
||
impl<'tcx> Debug for Statement<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
use self::StatementKind::*;
|
||
match self.kind {
|
||
Assign(ref lv, ref rv) => write!(fmt, "{:?} = {:?}", lv, rv)
|
||
}
|
||
}
|
||
}
|
||
///////////////////////////////////////////////////////////////////////////
|
||
// Lvalues
|
||
|
||
/// A path to a value; something that can be evaluated without
|
||
/// changing or disturbing program state.
|
||
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
|
||
pub enum Lvalue<'tcx> {
|
||
/// local variable declared by the user
|
||
Var(u32),
|
||
|
||
/// temporary introduced during lowering into MIR
|
||
Temp(u32),
|
||
|
||
/// formal parameter of the function; note that these are NOT the
|
||
/// bindings that the user declares, which are vars
|
||
Arg(u32),
|
||
|
||
/// static or static mut variable
|
||
Static(DefId),
|
||
|
||
/// the return pointer of the fn
|
||
ReturnPointer,
|
||
|
||
/// projection out of an lvalue (access a field, deref a pointer, etc)
|
||
Projection(Box<LvalueProjection<'tcx>>),
|
||
}
|
||
|
||
/// The `Projection` data structure defines things of the form `B.x`
|
||
/// or `*B` or `B[index]`. Note that it is parameterized because it is
|
||
/// shared between `Constant` and `Lvalue`. See the aliases
|
||
/// `LvalueProjection` etc below.
|
||
#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
||
pub struct Projection<'tcx, B, V> {
|
||
pub base: B,
|
||
pub elem: ProjectionElem<'tcx, V>,
|
||
}
|
||
|
||
#[derive(Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
||
pub enum ProjectionElem<'tcx, V> {
|
||
Deref,
|
||
Field(Field, Ty<'tcx>),
|
||
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,
|
||
},
|
||
|
||
/// "Downcast" to a variant of an ADT. Currently, we only introduce
|
||
/// this for ADTs with more than one variant. It may be better to
|
||
/// just introduce it always, or always for enums.
|
||
Downcast(AdtDef<'tcx>, usize),
|
||
}
|
||
|
||
/// Alias for projections as they appear in lvalues, where the base is an lvalue
|
||
/// and the index is an operand.
|
||
pub type LvalueProjection<'tcx> = Projection<'tcx, Lvalue<'tcx>, Operand<'tcx>>;
|
||
|
||
/// Alias for projections as they appear in lvalues, where the base is an lvalue
|
||
/// and the index is an operand.
|
||
pub type LvalueElem<'tcx> = ProjectionElem<'tcx, Operand<'tcx>>;
|
||
|
||
/// Index into the list of fields found in a `VariantDef`
|
||
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
||
pub struct Field(u32);
|
||
|
||
impl Field {
|
||
pub fn new(value: usize) -> Field {
|
||
assert!(value < (u32::MAX) as usize);
|
||
Field(value as u32)
|
||
}
|
||
|
||
pub fn index(self) -> usize {
|
||
self.0 as usize
|
||
}
|
||
}
|
||
|
||
impl<'tcx> Lvalue<'tcx> {
|
||
pub fn field(self, f: Field, ty: Ty<'tcx>) -> Lvalue<'tcx> {
|
||
self.elem(ProjectionElem::Field(f, ty))
|
||
}
|
||
|
||
pub fn deref(self) -> Lvalue<'tcx> {
|
||
self.elem(ProjectionElem::Deref)
|
||
}
|
||
|
||
pub fn index(self, index: Operand<'tcx>) -> Lvalue<'tcx> {
|
||
self.elem(ProjectionElem::Index(index))
|
||
}
|
||
|
||
pub fn elem(self, elem: LvalueElem<'tcx>) -> Lvalue<'tcx> {
|
||
Lvalue::Projection(Box::new(LvalueProjection {
|
||
base: self,
|
||
elem: elem,
|
||
}))
|
||
}
|
||
}
|
||
|
||
impl<'tcx> Debug for Lvalue<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
use self::Lvalue::*;
|
||
|
||
match *self {
|
||
Var(id) =>
|
||
write!(fmt, "var{:?}", id),
|
||
Arg(id) =>
|
||
write!(fmt, "arg{:?}", id),
|
||
Temp(id) =>
|
||
write!(fmt, "tmp{:?}", id),
|
||
Static(def_id) =>
|
||
write!(fmt, "{}", ty::tls::with(|tcx| tcx.item_path_str(def_id))),
|
||
ReturnPointer =>
|
||
write!(fmt, "return"),
|
||
Projection(ref data) =>
|
||
match data.elem {
|
||
ProjectionElem::Downcast(ref adt_def, index) =>
|
||
write!(fmt, "({:?} as {})", data.base, adt_def.variants[index].name),
|
||
ProjectionElem::Deref =>
|
||
write!(fmt, "(*{:?})", data.base),
|
||
ProjectionElem::Field(field, ty) =>
|
||
write!(fmt, "({:?}.{:?}: {:?})", data.base, field.index(), ty),
|
||
ProjectionElem::Index(ref index) =>
|
||
write!(fmt, "{:?}[{:?}]", data.base, index),
|
||
ProjectionElem::ConstantIndex { offset, min_length, from_end: false } =>
|
||
write!(fmt, "{:?}[{:?} of {:?}]", data.base, offset, min_length),
|
||
ProjectionElem::ConstantIndex { offset, min_length, from_end: true } =>
|
||
write!(fmt, "{:?}[-{:?} of {:?}]", data.base, offset, min_length),
|
||
},
|
||
}
|
||
}
|
||
}
|
||
|
||
///////////////////////////////////////////////////////////////////////////
|
||
// Operands
|
||
//
|
||
/// These are values that can appear inside an rvalue (or an index
|
||
/// lvalue). They are intentionally limited to prevent rvalues from
|
||
/// being nested in one another.
|
||
|
||
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable)]
|
||
pub enum Operand<'tcx> {
|
||
Consume(Lvalue<'tcx>),
|
||
Constant(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),
|
||
Consume(ref lv) => write!(fmt, "{:?}", lv),
|
||
}
|
||
}
|
||
}
|
||
|
||
///////////////////////////////////////////////////////////////////////////
|
||
/// Rvalues
|
||
|
||
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
||
pub enum Rvalue<'tcx> {
|
||
/// x (either a move or copy, depending on type of x)
|
||
Use(Operand<'tcx>),
|
||
|
||
/// [x; 32]
|
||
Repeat(Operand<'tcx>, TypedConstVal<'tcx>),
|
||
|
||
/// &x or &mut x
|
||
Ref(Region, BorrowKind, Lvalue<'tcx>),
|
||
|
||
/// length of a [X] or [X;n] value
|
||
Len(Lvalue<'tcx>),
|
||
|
||
Cast(CastKind, Operand<'tcx>, Ty<'tcx>),
|
||
|
||
BinaryOp(BinOp, Operand<'tcx>, Operand<'tcx>),
|
||
|
||
UnaryOp(UnOp, Operand<'tcx>),
|
||
|
||
/// Creates an *uninitialized* Box
|
||
Box(Ty<'tcx>),
|
||
|
||
/// Create an aggregate value, like a tuple or struct. This is
|
||
/// only needed because we want to distinguish `dest = Foo { x:
|
||
/// ..., y: ... }` from `dest.x = ...; dest.y = ...;` in the case
|
||
/// that `Foo` has a destructor. These rvalues can be optimized
|
||
/// away after type-checking and before lowering.
|
||
Aggregate(AggregateKind<'tcx>, Vec<Operand<'tcx>>),
|
||
|
||
/// Generates a slice of the form `&input[from_start..L-from_end]`
|
||
/// where `L` is the length of the slice. This is only created by
|
||
/// slice pattern matching, so e.g. a pattern of the form `[x, y,
|
||
/// .., z]` might create a slice with `from_start=2` and
|
||
/// `from_end=1`.
|
||
Slice {
|
||
input: Lvalue<'tcx>,
|
||
from_start: usize,
|
||
from_end: usize,
|
||
},
|
||
|
||
InlineAsm {
|
||
asm: InlineAsm,
|
||
outputs: Vec<Lvalue<'tcx>>,
|
||
inputs: Vec<Operand<'tcx>>
|
||
}
|
||
}
|
||
|
||
#[derive(Clone, Copy, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
|
||
pub enum CastKind {
|
||
Misc,
|
||
|
||
/// Convert unique, zero-sized type for a fn to fn()
|
||
ReifyFnPointer,
|
||
|
||
/// Convert safe fn() to unsafe fn()
|
||
UnsafeFnPointer,
|
||
|
||
/// "Unsize" -- convert a thin-or-fat pointer to a fat pointer.
|
||
/// trans must figure out the details once full monomorphization
|
||
/// is known. For example, this could be used to cast from a
|
||
/// `&[i32;N]` to a `&[i32]`, or a `Box<T>` to a `Box<Trait>`
|
||
/// (presuming `T: Trait`).
|
||
Unsize,
|
||
}
|
||
|
||
#[derive(Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
|
||
pub enum AggregateKind<'tcx> {
|
||
Vec,
|
||
Tuple,
|
||
Adt(AdtDef<'tcx>, usize, &'tcx Substs<'tcx>),
|
||
Closure(DefId, &'tcx ClosureSubsts<'tcx>),
|
||
}
|
||
|
||
#[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
|
||
pub enum BinOp {
|
||
/// The `+` operator (addition)
|
||
Add,
|
||
/// The `-` operator (subtraction)
|
||
Sub,
|
||
/// The `*` operator (multiplication)
|
||
Mul,
|
||
/// The `/` operator (division)
|
||
Div,
|
||
/// The `%` operator (modulus)
|
||
Rem,
|
||
/// The `^` operator (bitwise xor)
|
||
BitXor,
|
||
/// The `&` operator (bitwise and)
|
||
BitAnd,
|
||
/// The `|` operator (bitwise or)
|
||
BitOr,
|
||
/// The `<<` operator (shift left)
|
||
Shl,
|
||
/// The `>>` operator (shift right)
|
||
Shr,
|
||
/// The `==` operator (equality)
|
||
Eq,
|
||
/// The `<` operator (less than)
|
||
Lt,
|
||
/// The `<=` operator (less than or equal to)
|
||
Le,
|
||
/// The `!=` operator (not equal to)
|
||
Ne,
|
||
/// The `>=` operator (greater than or equal to)
|
||
Ge,
|
||
/// The `>` operator (greater than)
|
||
Gt,
|
||
}
|
||
|
||
#[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable)]
|
||
pub enum UnOp {
|
||
/// The `!` operator for logical inversion
|
||
Not,
|
||
/// The `-` operator for negation
|
||
Neg,
|
||
}
|
||
|
||
impl<'tcx> Debug for Rvalue<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
use self::Rvalue::*;
|
||
|
||
match *self {
|
||
Use(ref lvalue) => write!(fmt, "{:?}", lvalue),
|
||
Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b),
|
||
Len(ref a) => write!(fmt, "Len({:?})", a),
|
||
Cast(ref kind, ref lv, ref ty) => write!(fmt, "{:?} as {:?} ({:?})", lv, ty, kind),
|
||
BinaryOp(ref op, ref a, ref b) => write!(fmt, "{:?}({:?}, {:?})", op, a, b),
|
||
UnaryOp(ref op, ref a) => write!(fmt, "{:?}({:?})", op, a),
|
||
Box(ref t) => write!(fmt, "Box({:?})", t),
|
||
InlineAsm { ref asm, ref outputs, ref inputs } => {
|
||
write!(fmt, "asm!({:?} : {:?} : {:?})", asm, outputs, inputs)
|
||
}
|
||
Slice { ref input, from_start, from_end } =>
|
||
write!(fmt, "{:?}[{:?}..-{:?}]", input, from_start, from_end),
|
||
|
||
Ref(_, borrow_kind, ref lv) => {
|
||
let kind_str = match borrow_kind {
|
||
BorrowKind::Shared => "",
|
||
BorrowKind::Mut | BorrowKind::Unique => "mut ",
|
||
};
|
||
write!(fmt, "&{}{:?}", kind_str, lv)
|
||
}
|
||
|
||
Aggregate(ref kind, ref lvs) => {
|
||
use self::AggregateKind::*;
|
||
|
||
fn fmt_tuple(fmt: &mut Formatter, lvs: &[Operand]) -> fmt::Result {
|
||
let mut tuple_fmt = fmt.debug_tuple("");
|
||
for lv in lvs {
|
||
tuple_fmt.field(lv);
|
||
}
|
||
tuple_fmt.finish()
|
||
}
|
||
|
||
match *kind {
|
||
Vec => write!(fmt, "{:?}", lvs),
|
||
|
||
Tuple => {
|
||
match lvs.len() {
|
||
0 => write!(fmt, "()"),
|
||
1 => write!(fmt, "({:?},)", lvs[0]),
|
||
_ => fmt_tuple(fmt, lvs),
|
||
}
|
||
}
|
||
|
||
Adt(adt_def, variant, substs) => {
|
||
let variant_def = &adt_def.variants[variant];
|
||
|
||
ppaux::parameterized(fmt, substs, variant_def.did,
|
||
ppaux::Ns::Value, &[],
|
||
|tcx| {
|
||
tcx.lookup_item_type(variant_def.did).generics
|
||
})?;
|
||
|
||
match variant_def.kind() {
|
||
ty::VariantKind::Unit => Ok(()),
|
||
ty::VariantKind::Tuple => fmt_tuple(fmt, lvs),
|
||
ty::VariantKind::Struct => {
|
||
let mut struct_fmt = fmt.debug_struct("");
|
||
for (field, lv) in variant_def.fields.iter().zip(lvs) {
|
||
struct_fmt.field(&field.name.as_str(), lv);
|
||
}
|
||
struct_fmt.finish()
|
||
}
|
||
}
|
||
}
|
||
|
||
Closure(def_id, _) => ty::tls::with(|tcx| {
|
||
if let Some(node_id) = tcx.map.as_local_node_id(def_id) {
|
||
let name = format!("[closure@{:?}]", tcx.map.span(node_id));
|
||
let mut struct_fmt = fmt.debug_struct(&name);
|
||
|
||
tcx.with_freevars(node_id, |freevars| {
|
||
for (freevar, lv) in freevars.iter().zip(lvs) {
|
||
let var_name = tcx.local_var_name_str(freevar.def.var_id());
|
||
struct_fmt.field(&var_name, lv);
|
||
}
|
||
});
|
||
|
||
struct_fmt.finish()
|
||
} else {
|
||
write!(fmt, "[closure]")
|
||
}
|
||
}),
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
///////////////////////////////////////////////////////////////////////////
|
||
/// Constants
|
||
///
|
||
/// Two constants are equal if they are the same constant. Note that
|
||
/// this does not necessarily mean that they are "==" in Rust -- in
|
||
/// particular one must be wary of `NaN`!
|
||
|
||
#[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
||
pub struct Constant<'tcx> {
|
||
pub span: Span,
|
||
pub ty: Ty<'tcx>,
|
||
pub literal: Literal<'tcx>,
|
||
}
|
||
|
||
#[derive(Clone, RustcEncodable, RustcDecodable)]
|
||
pub struct TypedConstVal<'tcx> {
|
||
pub ty: Ty<'tcx>,
|
||
pub span: Span,
|
||
pub value: ConstUsize,
|
||
}
|
||
|
||
impl<'tcx> Debug for TypedConstVal<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
write!(fmt, "const {}", ConstInt::Usize(self.value))
|
||
}
|
||
}
|
||
|
||
#[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
|
||
pub enum Literal<'tcx> {
|
||
Item {
|
||
def_id: DefId,
|
||
substs: &'tcx Substs<'tcx>,
|
||
},
|
||
Value {
|
||
value: ConstVal,
|
||
},
|
||
}
|
||
|
||
impl<'tcx> Debug for Constant<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
write!(fmt, "{:?}", self.literal)
|
||
}
|
||
}
|
||
|
||
impl<'tcx> Debug for Literal<'tcx> {
|
||
fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
|
||
use self::Literal::*;
|
||
match *self {
|
||
Item { def_id, substs } => {
|
||
ppaux::parameterized(fmt, substs, def_id, ppaux::Ns::Value, &[],
|
||
|tcx| tcx.lookup_item_type(def_id).generics)
|
||
}
|
||
Value { ref value } => {
|
||
write!(fmt, "const ")?;
|
||
fmt_const_val(fmt, value)
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Write a `ConstVal` in a way closer to the original source code than the `Debug` output.
|
||
fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ConstVal) -> fmt::Result {
|
||
use middle::const_eval::ConstVal::*;
|
||
match *const_val {
|
||
Float(f) => write!(fmt, "{:?}", f),
|
||
Integral(n) => write!(fmt, "{}", n),
|
||
Str(ref s) => write!(fmt, "{:?}", s),
|
||
ByteStr(ref bytes) => {
|
||
let escaped: String = bytes
|
||
.iter()
|
||
.flat_map(|&ch| ascii::escape_default(ch).map(|c| c as char))
|
||
.collect();
|
||
write!(fmt, "b\"{}\"", escaped)
|
||
}
|
||
Bool(b) => write!(fmt, "{:?}", b),
|
||
Function(def_id) => write!(fmt, "{}", item_path_str(def_id)),
|
||
Struct(node_id) | Tuple(node_id) | Array(node_id, _) | Repeat(node_id, _) =>
|
||
write!(fmt, "{}", node_to_string(node_id)),
|
||
Char(c) => write!(fmt, "{:?}", c),
|
||
Dummy => unreachable!(),
|
||
}
|
||
}
|
||
|
||
fn node_to_string(node_id: ast::NodeId) -> String {
|
||
ty::tls::with(|tcx| tcx.map.node_to_user_string(node_id))
|
||
}
|
||
|
||
fn item_path_str(def_id: DefId) -> String {
|
||
ty::tls::with(|tcx| tcx.item_path_str(def_id))
|
||
}
|