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::Symbol;
/// A `LitKind`-like enum to fold constant `Expr`s into.
#[derive(Debug, Clone)]
/// Parses a `LitKind` to a `Constant`.
pub fn lit_to_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
- use syntax::ast::*;
-
match *lit {
LitKind::Str(ref is, _) => Constant::Str(is.to_string()),
LitKind::Byte(b) => Constant::Int(u128::from(b)),
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) })
}
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.kind {
- ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id),
+ 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_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).kind {
- ty::Array(_, n) => n.eval_usize(self.lcx.tcx, self.lcx.param_env),
+ 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) => {
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()
- .copied()
- .map(Symbol::as_str)
- .collect::<Vec<_>>();
- if def_path[0] == "core";
- if def_path[1] == "num";
- if def_path[3] == "max_value";
- if def_path.len() == 4;
+ 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 &*def_path[2] {
+ 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) => {
}
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.kind {
/// 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;
-
+ 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::AssocConst, 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) {
}
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 {
ty::ConstKind::Value(ConstValue::Scalar(Scalar::Raw { data: d, .. })) => match result.ty.kind {
ty::Bool => Some(Constant::Bool(d == 1)),
},
_ => 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,
+ },
// FIXME: implement other conversions.
_ => None,
}