use crate::utils::{clip, higher, sext, unsext};
use if_chain::if_chain;
-use rustc::hir::def::{DefKind, Res};
-use rustc::hir::*;
-use rustc::lint::LateContext;
-use rustc::ty::subst::{Subst, SubstsRef};
-use rustc::ty::{self, Instance, Ty, TyCtxt};
-use rustc::{bug, span_bug};
+use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
use rustc_data_structures::sync::Lrc;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, QPath, UnOp};
+use rustc_lint::LateContext;
+use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
+use rustc_span::symbol::Symbol;
use std::cmp::Ordering::{self, Equal};
-use std::cmp::PartialOrd;
use std::convert::TryInto;
use std::hash::{Hash, Hasher};
-use syntax::ast::{FloatTy, LitKind};
-use syntax_pos::symbol::{LocalInternedString, Symbol};
/// A `LitKind`-like enum to fold constant `Expr`s into.
#[derive(Debug, Clone)]
impl PartialEq for Constant {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
- (&Constant::Str(ref ls), &Constant::Str(ref rs)) => ls == rs,
- (&Constant::Binary(ref l), &Constant::Binary(ref r)) => l == r,
- (&Constant::Char(l), &Constant::Char(r)) => l == r,
- (&Constant::Int(l), &Constant::Int(r)) => l == r,
- (&Constant::F64(l), &Constant::F64(r)) => {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => ls == rs,
+ (&Self::Binary(ref l), &Self::Binary(ref r)) => l == r,
+ (&Self::Char(l), &Self::Char(r)) => l == r,
+ (&Self::Int(l), &Self::Int(r)) => l == r,
+ (&Self::F64(l), &Self::F64(r)) => {
// We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
// `Fw32 == Fw64`, so don’t compare them.
// `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
l.to_bits() == r.to_bits()
},
- (&Constant::F32(l), &Constant::F32(r)) => {
+ (&Self::F32(l), &Self::F32(r)) => {
// We want `Fw32 == FwAny` and `FwAny == Fw64`, and by transitivity we must have
// `Fw32 == Fw64`, so don’t compare them.
// `to_bits` is required to catch non-matching 0.0, -0.0, and NaNs.
f64::from(l).to_bits() == f64::from(r).to_bits()
},
- (&Constant::Bool(l), &Constant::Bool(r)) => l == r,
- (&Constant::Vec(ref l), &Constant::Vec(ref r)) | (&Constant::Tuple(ref l), &Constant::Tuple(ref r)) => {
- l == r
- },
- (&Constant::Repeat(ref lv, ref ls), &Constant::Repeat(ref rv, ref rs)) => ls == rs && lv == rv,
+ (&Self::Bool(l), &Self::Bool(r)) => l == r,
+ (&Self::Vec(ref l), &Self::Vec(ref r)) | (&Self::Tuple(ref l), &Self::Tuple(ref r)) => l == r,
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => ls == rs && lv == rv,
// TODO: are there inter-type equalities?
_ => false,
}
{
std::mem::discriminant(self).hash(state);
match *self {
- Constant::Str(ref s) => {
+ Self::Str(ref s) => {
s.hash(state);
},
- Constant::Binary(ref b) => {
+ Self::Binary(ref b) => {
b.hash(state);
},
- Constant::Char(c) => {
+ Self::Char(c) => {
c.hash(state);
},
- Constant::Int(i) => {
+ Self::Int(i) => {
i.hash(state);
},
- Constant::F32(f) => {
+ Self::F32(f) => {
f64::from(f).to_bits().hash(state);
},
- Constant::F64(f) => {
+ Self::F64(f) => {
f.to_bits().hash(state);
},
- Constant::Bool(b) => {
+ Self::Bool(b) => {
b.hash(state);
},
- Constant::Vec(ref v) | Constant::Tuple(ref v) => {
+ Self::Vec(ref v) | Self::Tuple(ref v) => {
v.hash(state);
},
- Constant::Repeat(ref c, l) => {
+ Self::Repeat(ref c, l) => {
c.hash(state);
l.hash(state);
},
- Constant::RawPtr(u) => {
+ Self::RawPtr(u) => {
u.hash(state);
},
- Constant::Err(ref s) => {
+ Self::Err(ref s) => {
s.hash(state);
},
}
}
impl Constant {
- pub fn partial_cmp(tcx: TyCtxt<'_, '_, '_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option<Ordering> {
+ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option<Ordering> {
match (left, right) {
- (&Constant::Str(ref ls), &Constant::Str(ref rs)) => Some(ls.cmp(rs)),
- (&Constant::Char(ref l), &Constant::Char(ref r)) => Some(l.cmp(r)),
- (&Constant::Int(l), &Constant::Int(r)) => {
- if let ty::Int(int_ty) = cmp_type.sty {
+ (&Self::Str(ref ls), &Self::Str(ref rs)) => Some(ls.cmp(rs)),
+ (&Self::Char(ref l), &Self::Char(ref r)) => Some(l.cmp(r)),
+ (&Self::Int(l), &Self::Int(r)) => {
+ if let ty::Int(int_ty) = cmp_type.kind {
Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty)))
} else {
Some(l.cmp(&r))
}
},
- (&Constant::F64(l), &Constant::F64(r)) => l.partial_cmp(&r),
- (&Constant::F32(l), &Constant::F32(r)) => l.partial_cmp(&r),
- (&Constant::Bool(ref l), &Constant::Bool(ref r)) => Some(l.cmp(r)),
- (&Constant::Tuple(ref l), &Constant::Tuple(ref r)) | (&Constant::Vec(ref l), &Constant::Vec(ref r)) => l
+ (&Self::F64(l), &Self::F64(r)) => l.partial_cmp(&r),
+ (&Self::F32(l), &Self::F32(r)) => l.partial_cmp(&r),
+ (&Self::Bool(ref l), &Self::Bool(ref r)) => Some(l.cmp(r)),
+ (&Self::Tuple(ref l), &Self::Tuple(ref r)) | (&Self::Vec(ref l), &Self::Vec(ref r)) => l
.iter()
.zip(r.iter())
.map(|(li, ri)| Self::partial_cmp(tcx, cmp_type, li, ri))
.find(|r| r.map_or(true, |o| o != Ordering::Equal))
.unwrap_or_else(|| Some(l.len().cmp(&r.len()))),
- (&Constant::Repeat(ref lv, ref ls), &Constant::Repeat(ref rv, ref rs)) => {
+ (&Self::Repeat(ref lv, ref ls), &Self::Repeat(ref rv, ref rs)) => {
match Self::partial_cmp(tcx, cmp_type, lv, rv) {
Some(Equal) => Some(ls.cmp(rs)),
x => x,
}
/// Parses a `LitKind` to a `Constant`.
-pub fn lit_to_constant<'tcx>(lit: &LitKind, ty: Ty<'tcx>) -> Constant {
- use syntax::ast::*;
-
+pub fn lit_to_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
match *lit {
LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
LitKind::Byte(b) => Constant::Int(u128::from(b)),
LitKind::ByteStr(ref s) => Constant::Binary(Lrc::clone(s)),
LitKind::Char(c) => Constant::Char(c),
LitKind::Int(n, _) => Constant::Int(n),
- LitKind::Float(ref is, _) | LitKind::FloatUnsuffixed(ref is) => match ty.sty {
+ LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
+ FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+ FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
+ },
+ LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind {
ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
ty::Float(FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()),
_ => bug!(),
pub fn constant<'c, 'cc>(
lcx: &LateContext<'c, 'cc>,
tables: &'c ty::TypeckTables<'cc>,
- e: &Expr,
+ e: &Expr<'_>,
) -> Option<(Constant, bool)> {
let mut cx = ConstEvalLateContext {
lcx,
pub fn constant_simple<'c, 'cc>(
lcx: &LateContext<'c, 'cc>,
tables: &'c ty::TypeckTables<'cc>,
- e: &Expr,
+ e: &Expr<'_>,
) -> Option<Constant> {
constant(lcx, tables, e).and_then(|(cst, res)| if res { None } else { Some(cst) })
}
}
}
-pub struct ConstEvalLateContext<'a, 'tcx: 'a> {
+pub struct ConstEvalLateContext<'a, 'tcx> {
lcx: &'a LateContext<'a, 'tcx>,
tables: &'a ty::TypeckTables<'tcx>,
param_env: ty::ParamEnv<'tcx>,
impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
/// Simple constant folding: Insert an expression, get a constant or none.
- pub fn expr(&mut self, e: &Expr) -> Option<Constant> {
+ pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant> {
if let Some((ref cond, ref then, otherwise)) = higher::if_block(&e) {
return self.ifthenelse(cond, then, otherwise);
}
- match e.node {
- ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id),
+ match e.kind {
+ ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id, self.tables.expr_ty(e)),
ExprKind::Block(ref block, _) => self.block(block),
- ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty(e))),
+ ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty_opt(e))),
ExprKind::Array(ref vec) => self.multi(vec).map(Constant::Vec),
ExprKind::Tup(ref tup) => self.multi(tup).map(Constant::Tuple),
ExprKind::Repeat(ref value, _) => {
- let n = match self.tables.expr_ty(e).sty {
- ty::Array(_, n) => n.assert_usize(self.lcx.tcx).expect("array length"),
+ let n = match self.tables.expr_ty(e).kind {
+ ty::Array(_, n) => n.try_eval_usize(self.lcx.tcx, self.lcx.param_env)?,
_ => span_bug!(e.span, "typeck error"),
};
self.expr(value).map(|v| Constant::Repeat(Box::new(v), n))
},
ExprKind::Unary(op, ref operand) => self.expr(operand).and_then(|o| match op {
- UnNot => self.constant_not(&o, self.tables.expr_ty(e)),
- UnNeg => self.constant_negate(&o, self.tables.expr_ty(e)),
- UnDeref => Some(o),
+ UnOp::UnNot => self.constant_not(&o, self.tables.expr_ty(e)),
+ UnOp::UnNeg => self.constant_negate(&o, self.tables.expr_ty(e)),
+ UnOp::UnDeref => Some(o),
}),
ExprKind::Binary(op, ref left, ref right) => self.binop(op, left, right),
ExprKind::Call(ref callee, ref args) => {
// We only handle a few const functions for now.
if_chain! {
if args.is_empty();
- if let ExprKind::Path(qpath) = &callee.node;
+ if let ExprKind::Path(qpath) = &callee.kind;
let res = self.tables.qpath_res(qpath, callee.hir_id);
if let Some(def_id) = res.opt_def_id();
- let get_def_path = self.lcx.get_def_path(def_id);
- let def_path = get_def_path
- .iter()
- .map(LocalInternedString::get)
- .collect::<Vec<_>>();
- if let &["core", "num", impl_ty, "max_value"] = &def_path[..];
+ let def_path: Vec<_> = self.lcx.get_def_path(def_id).into_iter().map(Symbol::as_str).collect();
+ let def_path: Vec<&str> = def_path.iter().take(4).map(|s| &**s).collect();
+ if let ["core", "num", int_impl, "max_value"] = *def_path;
then {
- let value = match impl_ty {
+ let value = match int_impl {
"<impl i8>" => i8::max_value() as u128,
"<impl i16>" => i16::max_value() as u128,
"<impl i32>" => i32::max_value() as u128,
#[allow(clippy::cast_possible_wrap)]
fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
- use self::Constant::*;
+ use self::Constant::{Bool, Int};
match *o {
Bool(b) => Some(Bool(!b)),
Int(value) => {
let value = !value;
- match ty.sty {
+ match ty.kind {
ty::Int(ity) => Some(Int(unsext(self.lcx.tcx, value as i128, ity))),
ty::Uint(ity) => Some(Int(clip(self.lcx.tcx, value, ity))),
_ => None,
}
fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
- use self::Constant::*;
+ use self::Constant::{Int, F32, F64};
match *o {
Int(value) => {
- let ity = match ty.sty {
+ let ity = match ty.kind {
ty::Int(ity) => ity,
_ => return None,
};
/// Create `Some(Vec![..])` of all constants, unless there is any
/// non-constant part.
- fn multi(&mut self, vec: &[Expr]) -> Option<Vec<Constant>> {
+ fn multi(&mut self, vec: &[Expr<'_>]) -> Option<Vec<Constant>> {
vec.iter().map(|elem| self.expr(elem)).collect::<Option<_>>()
}
- /// Lookup a possibly constant expression from a ExprKind::Path.
- fn fetch_path(&mut self, qpath: &QPath, id: HirId) -> Option<Constant> {
- use rustc::mir::interpret::GlobalId;
-
+ /// Lookup a possibly constant expression from a `ExprKind::Path`.
+ fn fetch_path(&mut self, qpath: &QPath<'_>, id: HirId, ty: Ty<'cc>) -> Option<Constant> {
let res = self.tables.qpath_res(qpath, id);
match res {
- Res::Def(DefKind::Const, def_id) | Res::Def(DefKind::AssociatedConst, def_id) => {
+ Res::Def(DefKind::Const | DefKind::AssocConst, def_id) => {
let substs = self.tables.node_substs(id);
let substs = if self.substs.is_empty() {
substs
} else {
substs.subst(self.lcx.tcx, self.substs)
};
- let instance = Instance::resolve(self.lcx.tcx, self.param_env, def_id, substs)?;
- let gid = GlobalId {
- instance,
- promoted: None,
- };
- let result = self.lcx.tcx.const_eval(self.param_env.and(gid)).ok()?;
+ let result = self
+ .lcx
+ .tcx
+ .const_eval_resolve(self.param_env, def_id, substs, None, None)
+ .ok()
+ .map(|val| rustc_middle::ty::Const::from_value(self.lcx.tcx, val, ty))?;
let result = miri_to_const(&result);
if result.is_some() {
self.needed_resolution = true;
}
/// A block can only yield a constant if it only has one constant expression.
- fn block(&mut self, block: &Block) -> Option<Constant> {
+ fn block(&mut self, block: &Block<'_>) -> Option<Constant> {
if block.stmts.is_empty() {
block.expr.as_ref().and_then(|b| self.expr(b))
} else {
}
}
- fn ifthenelse(&mut self, cond: &Expr, then: &Expr, otherwise: Option<&Expr>) -> Option<Constant> {
+ fn ifthenelse(&mut self, cond: &Expr<'_>, then: &Expr<'_>, otherwise: Option<&Expr<'_>>) -> Option<Constant> {
if let Some(Constant::Bool(b)) = self.expr(cond) {
if b {
self.expr(&*then)
}
}
- fn binop(&mut self, op: BinOp, left: &Expr, right: &Expr) -> Option<Constant> {
+ fn binop(&mut self, op: BinOp, left: &Expr<'_>, right: &Expr<'_>) -> Option<Constant> {
let l = self.expr(left)?;
let r = self.expr(right);
match (l, r) {
- (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).sty {
+ (Constant::Int(l), Some(Constant::Int(r))) => match self.tables.expr_ty(left).kind {
ty::Int(ity) => {
let l = sext(self.lcx.tcx, l, ity);
let r = sext(self.lcx.tcx, r, ity);
}
pub fn miri_to_const(result: &ty::Const<'_>) -> Option<Constant> {
- use rustc::mir::interpret::{ConstValue, Scalar};
+ use rustc_middle::mir::interpret::{ConstValue, Scalar};
match result.val {
- ConstValue::Scalar(Scalar::Bits { bits: b, .. }) => match result.ty.sty {
- ty::Bool => Some(Constant::Bool(b == 1)),
- ty::Uint(_) | ty::Int(_) => Some(Constant::Int(b)),
+ ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data: d, .. })) => match result.ty.kind {
+ ty::Bool => Some(Constant::Bool(d == 1)),
+ ty::Uint(_) | ty::Int(_) => Some(Constant::Int(d)),
ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits(
- b.try_into().expect("invalid f32 bit representation"),
+ d.try_into().expect("invalid f32 bit representation"),
))),
ty::Float(FloatTy::F64) => Some(Constant::F64(f64::from_bits(
- b.try_into().expect("invalid f64 bit representation"),
+ d.try_into().expect("invalid f64 bit representation"),
))),
ty::RawPtr(type_and_mut) => {
- if let ty::Uint(_) = type_and_mut.ty.sty {
- return Some(Constant::RawPtr(b));
+ if let ty::Uint(_) = type_and_mut.ty.kind {
+ return Some(Constant::RawPtr(d));
}
None
},
// FIXME: implement other conversions.
_ => None,
},
- ConstValue::Slice { data, start, end } => match result.ty.sty {
- ty::Ref(_, tam, _) => match tam.sty {
- ty::Str => String::from_utf8(data.bytes[start..end].to_owned())
- .ok()
- .map(Constant::Str),
+ ty::ConstKind::Value(ConstValue::Slice { data, start, end }) => match result.ty.kind {
+ ty::Ref(_, tam, _) => match tam.kind {
+ ty::Str => String::from_utf8(
+ data.inspect_with_undef_and_ptr_outside_interpreter(start..end)
+ .to_owned(),
+ )
+ .ok()
+ .map(Constant::Str),
+ _ => None,
+ },
+ _ => None,
+ },
+ ty::ConstKind::Value(ConstValue::ByRef { alloc, offset: _ }) => match result.ty.kind {
+ ty::Array(sub_type, len) => match sub_type.kind {
+ ty::Float(FloatTy::F32) => match miri_to_const(len) {
+ Some(Constant::Int(len)) => alloc
+ .inspect_with_undef_and_ptr_outside_interpreter(0..(4 * len as usize))
+ .to_owned()
+ .chunks(4)
+ .map(|chunk| {
+ Some(Constant::F32(f32::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::<Option<Vec<Constant>>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ ty::Float(FloatTy::F64) => match miri_to_const(len) {
+ Some(Constant::Int(len)) => alloc
+ .inspect_with_undef_and_ptr_outside_interpreter(0..(8 * len as usize))
+ .to_owned()
+ .chunks(8)
+ .map(|chunk| {
+ Some(Constant::F64(f64::from_le_bytes(
+ chunk.try_into().expect("this shouldn't happen"),
+ )))
+ })
+ .collect::<Option<Vec<Constant>>>()
+ .map(Constant::Vec),
+ _ => None,
+ },
+ // FIXME: implement other array type conversions.
_ => None,
},
_ => None,