--- /dev/null
+#![allow(clippy::float_cmp)]
+
+use crate::{clip, sext, unsext};
+use if_chain::if_chain;
+use rustc_ast::ast::{self, 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::mir::interpret::Scalar;
+use rustc_middle::ty::subst::{Subst, SubstsRef};
+use rustc_middle::ty::{self, FloatTy, ScalarInt, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
+use rustc_span::symbol::Symbol;
+use std::cmp::Ordering::{self, Equal};
+use std::convert::TryInto;
+use std::hash::{Hash, Hasher};
+
+/// A `LitKind`-like enum to fold constant `Expr`s into.
+#[derive(Debug, Clone)]
+pub enum Constant {
+ /// A `String` (e.g., "abc").
+ Str(String),
+ /// A binary string (e.g., `b"abc"`).
+ Binary(Lrc<[u8]>),
+ /// A single `char` (e.g., `'a'`).
+ Char(char),
+ /// An integer's bit representation.
+ Int(u128),
+ /// An `f32`.
+ F32(f32),
+ /// An `f64`.
+ F64(f64),
+ /// `true` or `false`.
+ Bool(bool),
+ /// An array of constants.
+ Vec(Vec<Constant>),
+ /// Also an array, but with only one constant, repeated N times.
+ Repeat(Box<Constant>, u64),
+ /// A tuple of constants.
+ Tuple(Vec<Constant>),
+ /// A raw pointer.
+ RawPtr(u128),
+ /// A reference
+ Ref(Box<Constant>),
+ /// A literal with syntax error.
+ Err(Symbol),
+}
+
+impl PartialEq for Constant {
+ fn eq(&self, other: &Self) -> bool {
+ match (self, other) {
+ (&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()
+ },
+ (&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()
+ },
+ (&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,
+ (&Self::Ref(ref lb), &Self::Ref(ref rb)) => *lb == *rb,
+ // TODO: are there inter-type equalities?
+ _ => false,
+ }
+ }
+}
+
+impl Hash for Constant {
+ fn hash<H>(&self, state: &mut H)
+ where
+ H: Hasher,
+ {
+ std::mem::discriminant(self).hash(state);
+ match *self {
+ Self::Str(ref s) => {
+ s.hash(state);
+ },
+ Self::Binary(ref b) => {
+ b.hash(state);
+ },
+ Self::Char(c) => {
+ c.hash(state);
+ },
+ Self::Int(i) => {
+ i.hash(state);
+ },
+ Self::F32(f) => {
+ f64::from(f).to_bits().hash(state);
+ },
+ Self::F64(f) => {
+ f.to_bits().hash(state);
+ },
+ Self::Bool(b) => {
+ b.hash(state);
+ },
+ Self::Vec(ref v) | Self::Tuple(ref v) => {
+ v.hash(state);
+ },
+ Self::Repeat(ref c, l) => {
+ c.hash(state);
+ l.hash(state);
+ },
+ Self::RawPtr(u) => {
+ u.hash(state);
+ },
+ Self::Ref(ref r) => {
+ r.hash(state);
+ },
+ Self::Err(ref s) => {
+ s.hash(state);
+ },
+ }
+ }
+}
+
+impl Constant {
+ pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option<Ordering> {
+ match (left, right) {
+ (&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))
+ }
+ },
+ (&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()))),
+ (&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,
+ }
+ },
+ (&Self::Ref(ref lb), &Self::Ref(ref rb)) => Self::partial_cmp(tcx, cmp_type, lb, rb),
+ // TODO: are there any useful inter-type orderings?
+ _ => None,
+ }
+ }
+}
+
+/// Parses a `LitKind` to a `Constant`.
+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, LitFloatType::Suffixed(fty)) => match fty {
+ ast::FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+ ast::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!(),
+ },
+ LitKind::Bool(b) => Constant::Bool(b),
+ LitKind::Err(s) => Constant::Err(s),
+ }
+}
+
+pub fn constant<'tcx>(
+ lcx: &LateContext<'tcx>,
+ typeck_results: &ty::TypeckResults<'tcx>,
+ e: &Expr<'_>,
+) -> Option<(Constant, bool)> {
+ let mut cx = ConstEvalLateContext {
+ lcx,
+ typeck_results,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ };
+ cx.expr(e).map(|cst| (cst, cx.needed_resolution))
+}
+
+pub fn constant_simple<'tcx>(
+ lcx: &LateContext<'tcx>,
+ typeck_results: &ty::TypeckResults<'tcx>,
+ e: &Expr<'_>,
+) -> Option<Constant> {
+ constant(lcx, typeck_results, e).and_then(|(cst, res)| if res { None } else { Some(cst) })
+}
+
+/// Creates a `ConstEvalLateContext` from the given `LateContext` and `TypeckResults`.
+pub fn constant_context<'a, 'tcx>(
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'a ty::TypeckResults<'tcx>,
+) -> ConstEvalLateContext<'a, 'tcx> {
+ ConstEvalLateContext {
+ lcx,
+ typeck_results,
+ param_env: lcx.param_env,
+ needed_resolution: false,
+ substs: lcx.tcx.intern_substs(&[]),
+ }
+}
+
+pub struct ConstEvalLateContext<'a, 'tcx> {
+ lcx: &'a LateContext<'tcx>,
+ typeck_results: &'a ty::TypeckResults<'tcx>,
+ param_env: ty::ParamEnv<'tcx>,
+ needed_resolution: bool,
+ substs: SubstsRef<'tcx>,
+}
+
+impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> {
+ /// Simple constant folding: Insert an expression, get a constant or none.
+ pub fn expr(&mut self, e: &Expr<'_>) -> Option<Constant> {
+ match e.kind {
+ ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id, self.typeck_results.expr_ty(e)),
+ ExprKind::Block(ref block, _) => self.block(block),
+ ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.typeck_results.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.typeck_results.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 {
+ UnOp::Not => self.constant_not(&o, self.typeck_results.expr_ty(e)),
+ UnOp::Neg => self.constant_negate(&o, self.typeck_results.expr_ty(e)),
+ UnOp::Deref => Some(if let Constant::Ref(r) = o { *r } else { o }),
+ }),
+ ExprKind::If(ref cond, ref then, ref otherwise) => self.ifthenelse(cond, then, *otherwise),
+ 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.kind;
+ let res = self.typeck_results.qpath_res(qpath, callee.hir_id);
+ if let Some(def_id) = res.opt_def_id();
+ 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 int_impl {
+ "<impl i8>" => i8::MAX as u128,
+ "<impl i16>" => i16::MAX as u128,
+ "<impl i32>" => i32::MAX as u128,
+ "<impl i64>" => i64::MAX as u128,
+ "<impl i128>" => i128::MAX as u128,
+ _ => return None,
+ };
+ Some(Constant::Int(value))
+ }
+ else {
+ None
+ }
+ }
+ },
+ ExprKind::Index(ref arr, ref index) => self.index(arr, index),
+ ExprKind::AddrOf(_, _, ref inner) => self.expr(inner).map(|r| Constant::Ref(Box::new(r))),
+ // TODO: add other expressions.
+ _ => None,
+ }
+ }
+
+ #[allow(clippy::cast_possible_wrap)]
+ fn constant_not(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
+ use self::Constant::{Bool, Int};
+ match *o {
+ Bool(b) => Some(Bool(!b)),
+ Int(value) => {
+ let value = !value;
+ 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,
+ }
+ },
+ _ => None,
+ }
+ }
+
+ fn constant_negate(&self, o: &Constant, ty: Ty<'_>) -> Option<Constant> {
+ use self::Constant::{Int, F32, F64};
+ match *o {
+ Int(value) => {
+ let ity = match *ty.kind() {
+ ty::Int(ity) => ity,
+ _ => return None,
+ };
+ // sign extend
+ let value = sext(self.lcx.tcx, value, ity);
+ let value = value.checked_neg()?;
+ // clear unused bits
+ Some(Int(unsext(self.lcx.tcx, value, ity)))
+ },
+ F32(f) => Some(F32(-f)),
+ F64(f) => Some(F64(-f)),
+ _ => None,
+ }
+ }
+
+ /// Create `Some(Vec![..])` of all constants, unless there is any
+ /// non-constant part.
+ 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, ty: Ty<'tcx>) -> Option<Constant> {
+ let res = self.typeck_results.qpath_res(qpath, id);
+ match res {
+ Res::Def(DefKind::Const | DefKind::AssocConst, def_id) => {
+ let substs = self.typeck_results.node_substs(id);
+ let substs = if self.substs.is_empty() {
+ substs
+ } else {
+ substs.subst(self.lcx.tcx, self.substs)
+ };
+
+ let result = self
+ .lcx
+ .tcx
+ .const_eval_resolve(
+ self.param_env,
+ ty::WithOptConstParam::unknown(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;
+ }
+ result
+ },
+ // FIXME: cover all usable cases.
+ _ => None,
+ }
+ }
+
+ fn index(&mut self, lhs: &'_ Expr<'_>, index: &'_ Expr<'_>) -> Option<Constant> {
+ let lhs = self.expr(lhs);
+ let index = self.expr(index);
+
+ match (lhs, index) {
+ (Some(Constant::Vec(vec)), Some(Constant::Int(index))) => match vec.get(index as usize) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ },
+ (Some(Constant::Vec(vec)), _) => {
+ if !vec.is_empty() && vec.iter().all(|x| *x == vec[0]) {
+ match vec.get(0) {
+ Some(Constant::F32(x)) => Some(Constant::F32(*x)),
+ Some(Constant::F64(x)) => Some(Constant::F64(*x)),
+ _ => None,
+ }
+ } else {
+ None
+ }
+ },
+ _ => None,
+ }
+ }
+
+ /// A block can only yield a constant if it only has one constant expression.
+ fn block(&mut self, block: &Block<'_>) -> Option<Constant> {
+ if block.stmts.is_empty() {
+ block.expr.as_ref().and_then(|b| self.expr(b))
+ } else {
+ None
+ }
+ }
+
+ 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)
+ } else {
+ otherwise.as_ref().and_then(|expr| self.expr(expr))
+ }
+ } else {
+ None
+ }
+ }
+
+ 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.typeck_results.expr_ty_opt(left)?.kind() {
+ ty::Int(ity) => {
+ let l = sext(self.lcx.tcx, l, ity);
+ let r = sext(self.lcx.tcx, r, ity);
+ let zext = |n: i128| Constant::Int(unsext(self.lcx.tcx, n, ity));
+ match op.node {
+ BinOpKind::Add => l.checked_add(r).map(zext),
+ BinOpKind::Sub => l.checked_sub(r).map(zext),
+ BinOpKind::Mul => l.checked_mul(r).map(zext),
+ BinOpKind::Div if r != 0 => l.checked_div(r).map(zext),
+ BinOpKind::Rem if r != 0 => l.checked_rem(r).map(zext),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("invalid shift")).map(zext),
+ BinOpKind::BitXor => Some(zext(l ^ r)),
+ BinOpKind::BitOr => Some(zext(l | r)),
+ BinOpKind::BitAnd => Some(zext(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ }
+ },
+ ty::Uint(_) => match op.node {
+ BinOpKind::Add => l.checked_add(r).map(Constant::Int),
+ BinOpKind::Sub => l.checked_sub(r).map(Constant::Int),
+ BinOpKind::Mul => l.checked_mul(r).map(Constant::Int),
+ BinOpKind::Div => l.checked_div(r).map(Constant::Int),
+ BinOpKind::Rem => l.checked_rem(r).map(Constant::Int),
+ BinOpKind::Shr => l.checked_shr(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::Shl => l.checked_shl(r.try_into().expect("shift too large")).map(Constant::Int),
+ BinOpKind::BitXor => Some(Constant::Int(l ^ r)),
+ BinOpKind::BitOr => Some(Constant::Int(l | r)),
+ BinOpKind::BitAnd => Some(Constant::Int(l & r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ _ => None,
+ },
+ (Constant::F32(l), Some(Constant::F32(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F32(l + r)),
+ BinOpKind::Sub => Some(Constant::F32(l - r)),
+ BinOpKind::Mul => Some(Constant::F32(l * r)),
+ BinOpKind::Div => Some(Constant::F32(l / r)),
+ BinOpKind::Rem => Some(Constant::F32(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (Constant::F64(l), Some(Constant::F64(r))) => match op.node {
+ BinOpKind::Add => Some(Constant::F64(l + r)),
+ BinOpKind::Sub => Some(Constant::F64(l - r)),
+ BinOpKind::Mul => Some(Constant::F64(l * r)),
+ BinOpKind::Div => Some(Constant::F64(l / r)),
+ BinOpKind::Rem => Some(Constant::F64(l % r)),
+ BinOpKind::Eq => Some(Constant::Bool(l == r)),
+ BinOpKind::Ne => Some(Constant::Bool(l != r)),
+ BinOpKind::Lt => Some(Constant::Bool(l < r)),
+ BinOpKind::Le => Some(Constant::Bool(l <= r)),
+ BinOpKind::Ge => Some(Constant::Bool(l >= r)),
+ BinOpKind::Gt => Some(Constant::Bool(l > r)),
+ _ => None,
+ },
+ (l, r) => match (op.node, l, r) {
+ (BinOpKind::And, Constant::Bool(false), _) => Some(Constant::Bool(false)),
+ (BinOpKind::Or, Constant::Bool(true), _) => Some(Constant::Bool(true)),
+ (BinOpKind::And, Constant::Bool(true), Some(r)) | (BinOpKind::Or, Constant::Bool(false), Some(r)) => {
+ Some(r)
+ },
+ (BinOpKind::BitXor, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l ^ r)),
+ (BinOpKind::BitAnd, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l & r)),
+ (BinOpKind::BitOr, Constant::Bool(l), Some(Constant::Bool(r))) => Some(Constant::Bool(l | r)),
+ _ => None,
+ },
+ }
+ }
+}
+
+pub fn miri_to_const(result: &ty::Const<'_>) -> Option<Constant> {
+ use rustc_middle::mir::interpret::ConstValue;
+ match result.val {
+ ty::ConstKind::Value(ConstValue::Scalar(Scalar::Int(int))) => {
+ match result.ty.kind() {
+ ty::Bool => Some(Constant::Bool(int == ScalarInt::TRUE)),
+ ty::Uint(_) | ty::Int(_) => Some(Constant::Int(int.assert_bits(int.size()))),
+ ty::Float(FloatTy::F32) => Some(Constant::F32(f32::from_bits(
+ int.try_into().expect("invalid f32 bit representation"),
+ ))),
+ ty::Float(FloatTy::F64) => Some(Constant::F64(f64::from_bits(
+ int.try_into().expect("invalid f64 bit representation"),
+ ))),
+ ty::RawPtr(type_and_mut) => {
+ if let ty::Uint(_) = type_and_mut.ty.kind() {
+ return Some(Constant::RawPtr(int.assert_bits(int.size())));
+ }
+ None
+ },
+ // FIXME: implement other conversions.
+ _ => None,
+ }
+ },
+ 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_uninit_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_uninit_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_uninit_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,
+ }
+}
projects / rustc.git / blobdiff