| #![allow(clippy::float_cmp)] |
| |
| use crate::source::{get_source_text, walk_span_to_context}; |
| use crate::{clip, is_direct_expn_of, 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, Item, ItemKind, Node, QPath, UnOp}; |
| use rustc_lexer::tokenize; |
| use rustc_lint::LateContext; |
| use rustc_middle::mir; |
| use rustc_middle::mir::interpret::Scalar; |
| use rustc_middle::ty::{self, EarlyBinder, FloatTy, ScalarInt, Ty, TyCtxt}; |
| use rustc_middle::ty::{List, SubstsRef}; |
| use rustc_middle::{bug, span_bug}; |
| use rustc_span::symbol::Symbol; |
| use rustc_span::SyntaxContext; |
| use std::cmp::Ordering::{self, Equal}; |
| use std::hash::{Hash, Hasher}; |
| use std::iter; |
| |
| /// 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, |
| } |
| |
| impl PartialEq for Constant { |
| fn eq(&self, other: &Self) -> bool { |
| match (self, other) { |
| (Self::Str(ls), Self::Str(rs)) => ls == rs, |
| (Self::Binary(l), Self::Binary(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(lv, ls), Self::Repeat(rv, rs)) => ls == rs && lv == rv, |
| (Self::Ref(lb), Self::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 => {}, |
| } |
| } |
| } |
| |
| impl Constant { |
| pub fn partial_cmp(tcx: TyCtxt<'_>, cmp_type: Ty<'_>, left: &Self, right: &Self) -> Option<Ordering> { |
| match (left, right) { |
| (Self::Str(ls), Self::Str(rs)) => Some(ls.cmp(rs)), |
| (Self::Char(l), Self::Char(r)) => Some(l.cmp(r)), |
| (&Self::Int(l), &Self::Int(r)) => match *cmp_type.kind() { |
| ty::Int(int_ty) => Some(sext(tcx, l, int_ty).cmp(&sext(tcx, r, int_ty))), |
| ty::Uint(_) => Some(l.cmp(&r)), |
| _ => bug!("Not an int type"), |
| }, |
| (&Self::F64(l), &Self::F64(r)) => l.partial_cmp(&r), |
| (&Self::F32(l), &Self::F32(r)) => l.partial_cmp(&r), |
| (Self::Bool(l), Self::Bool(r)) => Some(l.cmp(r)), |
| (Self::Tuple(l), Self::Tuple(r)) if l.len() == r.len() => match *cmp_type.kind() { |
| ty::Tuple(tys) if tys.len() == l.len() => l |
| .iter() |
| .zip(r) |
| .zip(tys) |
| .map(|((li, ri), cmp_type)| 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()))), |
| _ => None, |
| }, |
| (Self::Vec(l), Self::Vec(r)) => { |
| let (ty::Array(cmp_type, _) | ty::Slice(cmp_type)) = *cmp_type.kind() else { |
| return None |
| }; |
| iter::zip(l, r) |
| .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(lv, ls), Self::Repeat(rv, rs)) => { |
| match Self::partial_cmp( |
| tcx, |
| match *cmp_type.kind() { |
| ty::Array(ty, _) => ty, |
| _ => return None, |
| }, |
| lv, |
| rv, |
| ) { |
| Some(Equal) => Some(ls.cmp(rs)), |
| x => x, |
| } |
| }, |
| (Self::Ref(lb), Self::Ref(rb)) => Self::partial_cmp( |
| tcx, |
| match *cmp_type.kind() { |
| ty::Ref(_, ty, _) => ty, |
| _ => return None, |
| }, |
| lb, |
| rb, |
| ), |
| // TODO: are there any useful inter-type orderings? |
| _ => None, |
| } |
| } |
| |
| /// Returns the integer value or `None` if `self` or `val_type` is not integer type. |
| pub fn int_value(&self, cx: &LateContext<'_>, val_type: Ty<'_>) -> Option<FullInt> { |
| if let Constant::Int(const_int) = *self { |
| match *val_type.kind() { |
| ty::Int(ity) => Some(FullInt::S(sext(cx.tcx, const_int, ity))), |
| ty::Uint(_) => Some(FullInt::U(const_int)), |
| _ => None, |
| } |
| } else { |
| None |
| } |
| } |
| |
| #[must_use] |
| pub fn peel_refs(mut self) -> Self { |
| while let Constant::Ref(r) = self { |
| self = *r; |
| } |
| self |
| } |
| } |
| |
| /// Parses a `LitKind` to a `Constant`. |
| pub fn lit_to_mir_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, _) | LitKind::CStr(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 => Constant::Err, |
| } |
| } |
| |
| /// The source of a constant value. |
| pub enum ConstantSource { |
| /// The value is determined solely from the expression. |
| Local, |
| /// The value is dependent on a defined constant. |
| Constant, |
| } |
| impl ConstantSource { |
| pub fn is_local(&self) -> bool { |
| matches!(self, Self::Local) |
| } |
| } |
| |
| /// Attempts to evaluate the expression as a constant. |
| pub fn constant<'tcx>( |
| lcx: &LateContext<'tcx>, |
| typeck_results: &ty::TypeckResults<'tcx>, |
| e: &Expr<'_>, |
| ) -> Option<Constant> { |
| ConstEvalLateContext::new(lcx, typeck_results).expr(e) |
| } |
| |
| /// Attempts to evaluate the expression as a constant. |
| pub fn constant_with_source<'tcx>( |
| lcx: &LateContext<'tcx>, |
| typeck_results: &ty::TypeckResults<'tcx>, |
| e: &Expr<'_>, |
| ) -> Option<(Constant, ConstantSource)> { |
| let mut ctxt = ConstEvalLateContext::new(lcx, typeck_results); |
| let res = ctxt.expr(e); |
| res.map(|x| (x, ctxt.source)) |
| } |
| |
| /// Attempts to evaluate an expression only if it's value is not dependent on other items. |
| pub fn constant_simple<'tcx>( |
| lcx: &LateContext<'tcx>, |
| typeck_results: &ty::TypeckResults<'tcx>, |
| e: &Expr<'_>, |
| ) -> Option<Constant> { |
| constant_with_source(lcx, typeck_results, e).and_then(|(c, s)| s.is_local().then_some(c)) |
| } |
| |
| pub fn constant_full_int<'tcx>( |
| lcx: &LateContext<'tcx>, |
| typeck_results: &ty::TypeckResults<'tcx>, |
| e: &Expr<'_>, |
| ) -> Option<FullInt> { |
| constant_simple(lcx, typeck_results, e)?.int_value(lcx, typeck_results.expr_ty(e)) |
| } |
| |
| #[derive(Copy, Clone, Debug, Eq)] |
| pub enum FullInt { |
| S(i128), |
| U(u128), |
| } |
| |
| impl PartialEq for FullInt { |
| #[must_use] |
| fn eq(&self, other: &Self) -> bool { |
| self.cmp(other) == Ordering::Equal |
| } |
| } |
| |
| impl PartialOrd for FullInt { |
| #[must_use] |
| fn partial_cmp(&self, other: &Self) -> Option<Ordering> { |
| Some(self.cmp(other)) |
| } |
| } |
| |
| impl Ord for FullInt { |
| #[must_use] |
| fn cmp(&self, other: &Self) -> Ordering { |
| use FullInt::{S, U}; |
| |
| fn cmp_s_u(s: i128, u: u128) -> Ordering { |
| u128::try_from(s).map_or(Ordering::Less, |x| x.cmp(&u)) |
| } |
| |
| match (*self, *other) { |
| (S(s), S(o)) => s.cmp(&o), |
| (U(s), U(o)) => s.cmp(&o), |
| (S(s), U(o)) => cmp_s_u(s, o), |
| (U(s), S(o)) => cmp_s_u(o, s).reverse(), |
| } |
| } |
| } |
| |
| pub struct ConstEvalLateContext<'a, 'tcx> { |
| lcx: &'a LateContext<'tcx>, |
| typeck_results: &'a ty::TypeckResults<'tcx>, |
| param_env: ty::ParamEnv<'tcx>, |
| source: ConstantSource, |
| substs: SubstsRef<'tcx>, |
| } |
| |
| impl<'a, 'tcx> ConstEvalLateContext<'a, 'tcx> { |
| fn new(lcx: &'a LateContext<'tcx>, typeck_results: &'a ty::TypeckResults<'tcx>) -> Self { |
| Self { |
| lcx, |
| typeck_results, |
| param_env: lcx.param_env, |
| source: ConstantSource::Local, |
| substs: List::empty(), |
| } |
| } |
| |
| /// 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(block, _) => self.block(block), |
| ExprKind::Lit(lit) => { |
| if is_direct_expn_of(e.span, "cfg").is_some() { |
| None |
| } else { |
| Some(lit_to_mir_constant(&lit.node, self.typeck_results.expr_ty_opt(e))) |
| } |
| }, |
| ExprKind::Array(vec) => self.multi(vec).map(Constant::Vec), |
| ExprKind::Tup(tup) => self.multi(tup).map(Constant::Tuple), |
| ExprKind::Repeat(value, _) => { |
| let n = match self.typeck_results.expr_ty(e).kind() { |
| ty::Array(_, n) => n.try_eval_target_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, 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(cond, then, ref otherwise) => self.ifthenelse(cond, then, *otherwise), |
| ExprKind::Binary(op, left, right) => self.binop(op, left, right), |
| ExprKind::Call(callee, 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 = self.lcx.get_def_path(def_id); |
| let def_path: Vec<&str> = def_path.iter().take(4).map(Symbol::as_str).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(arr, index) => self.index(arr, index), |
| ExprKind::AddrOf(_, _, inner) => self.expr(inner).map(|r| Constant::Ref(Box::new(r))), |
| // TODO: add other expressions. |
| _ => None, |
| } |
| } |
| |
| #[expect(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 ty::Int(ity) = *ty.kind() else { 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 an `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) => { |
| // Check if this constant is based on `cfg!(..)`, |
| // which is NOT constant for our purposes. |
| if let Some(node) = self.lcx.tcx.hir().get_if_local(def_id) && |
| let Node::Item(&Item { |
| kind: ItemKind::Const(_, body_id), |
| .. |
| }) = node && |
| let Node::Expr(&Expr { |
| kind: ExprKind::Lit(_), |
| span, |
| .. |
| }) = self.lcx.tcx.hir().get(body_id.hir_id) && |
| is_direct_expn_of(span, "cfg").is_some() { |
| return None; |
| } |
| |
| let substs = self.typeck_results.node_substs(id); |
| let substs = if self.substs.is_empty() { |
| substs |
| } else { |
| EarlyBinder::new(substs).subst(self.lcx.tcx, self.substs) |
| }; |
| |
| let result = self |
| .lcx |
| .tcx |
| .const_eval_resolve(self.param_env, mir::UnevaluatedConst::new(def_id, substs), None) |
| .ok() |
| .map(|val| rustc_middle::mir::ConstantKind::from_value(val, ty))?; |
| let result = miri_to_const(self.lcx.tcx, result)?; |
| self.source = ConstantSource::Constant; |
| Some(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() |
| && let Some(expr) = block.expr |
| { |
| // Try to detect any `cfg`ed statements or empty macro expansions. |
| let span = block.span.data(); |
| if span.ctxt == SyntaxContext::root() { |
| if let Some(expr_span) = walk_span_to_context(expr.span, span.ctxt) |
| && let expr_lo = expr_span.lo() |
| && expr_lo >= span.lo |
| && let Some(src) = get_source_text(self.lcx, span.lo..expr_lo) |
| && let Some(src) = src.as_str() |
| { |
| use rustc_lexer::TokenKind::{Whitespace, LineComment, BlockComment, Semi, OpenBrace}; |
| if !tokenize(src) |
| .map(|t| t.kind) |
| .filter(|t| !matches!(t, Whitespace | LineComment { .. } | BlockComment { .. } | Semi)) |
| .eq([OpenBrace]) |
| { |
| self.source = ConstantSource::Constant; |
| } |
| } else { |
| // Unable to access the source. Assume a non-local dependency. |
| self.source = ConstantSource::Constant; |
| } |
| } |
| |
| self.expr(expr) |
| } 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().ok()?).map(zext), |
| BinOpKind::Shl => l.checked_shl(r.try_into().ok()?).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().ok()?).map(Constant::Int), |
| BinOpKind::Shl => l.checked_shl(r.try_into().ok()?).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<'tcx>(tcx: TyCtxt<'tcx>, result: mir::ConstantKind<'tcx>) -> Option<Constant> { |
| use rustc_middle::mir::interpret::ConstValue; |
| match result { |
| mir::ConstantKind::Val(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(_) => Some(Constant::RawPtr(int.assert_bits(int.size()))), |
| // FIXME: implement other conversions. |
| _ => None, |
| } |
| }, |
| mir::ConstantKind::Val(ConstValue::Slice { data, start, end }, _) => match result.ty().kind() { |
| ty::Ref(_, tam, _) => match tam.kind() { |
| ty::Str => String::from_utf8( |
| data.inner() |
| .inspect_with_uninit_and_ptr_outside_interpreter(start..end) |
| .to_owned(), |
| ) |
| .ok() |
| .map(Constant::Str), |
| _ => None, |
| }, |
| _ => None, |
| }, |
| mir::ConstantKind::Val(ConstValue::ByRef { alloc, offset: _ }, _) => match result.ty().kind() { |
| ty::Array(sub_type, len) => match sub_type.kind() { |
| ty::Float(FloatTy::F32) => match len.kind().try_to_target_usize(tcx) { |
| Some(len) => alloc |
| .inner() |
| .inspect_with_uninit_and_ptr_outside_interpreter(0..(4 * usize::try_from(len).unwrap())) |
| .to_owned() |
| .array_chunks::<4>() |
| .map(|&chunk| Some(Constant::F32(f32::from_le_bytes(chunk)))) |
| .collect::<Option<Vec<Constant>>>() |
| .map(Constant::Vec), |
| _ => None, |
| }, |
| ty::Float(FloatTy::F64) => match len.kind().try_to_target_usize(tcx) { |
| Some(len) => alloc |
| .inner() |
| .inspect_with_uninit_and_ptr_outside_interpreter(0..(8 * usize::try_from(len).unwrap())) |
| .to_owned() |
| .array_chunks::<8>() |
| .map(|&chunk| Some(Constant::F64(f64::from_le_bytes(chunk)))) |
| .collect::<Option<Vec<Constant>>>() |
| .map(Constant::Vec), |
| _ => None, |
| }, |
| // FIXME: implement other array type conversions. |
| _ => None, |
| }, |
| _ => None, |
| }, |
| // FIXME: implement other conversions. |
| _ => None, |
| } |
| } |
