+++ /dev/null
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-//! Lints statically known runtime failures
-
-use rustc::mir::*;
-use rustc::hir;
-use rustc::hir::map::Node;
-use rustc::mir::visit::Visitor;
-use rustc::mir::interpret::{Value, PrimVal, GlobalId};
-use rustc::middle::const_val::{ConstVal, ConstEvalErr, ErrKind};
-use rustc::hir::def::Def;
-use rustc::traits;
-use interpret::eval_body_with_mir;
-use rustc::ty::{TyCtxt, ParamEnv};
-use rustc::ty::Instance;
-use rustc::ty::layout::LayoutOf;
-use rustc::hir::def_id::DefId;
-use rustc::ty::subst::Substs;
-
-fn is_const<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> bool {
- if let Some(node) = tcx.hir.get_if_local(def_id) {
- match node {
- Node::NodeItem(&hir::Item {
- node: hir::ItemConst(..), ..
- }) => true,
- _ => false
- }
- } else {
- match tcx.describe_def(def_id) {
- Some(Def::Const(_)) => true,
- _ => false
- }
- }
-}
-
-pub fn check<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) {
- let mir = &tcx.optimized_mir(def_id);
- let substs = Substs::identity_for_item(tcx, def_id);
- let instance = Instance::new(def_id, substs);
- let param_env = tcx.param_env(def_id);
-
- if is_const(tcx, def_id) {
- let cid = GlobalId {
- instance,
- promoted: None,
- };
- eval_body_with_mir(tcx, cid, mir, param_env);
- }
-
- ConstErrVisitor {
- tcx,
- mir,
- }.visit_mir(mir);
- let outer_def_id = if tcx.is_closure(def_id) {
- tcx.closure_base_def_id(def_id)
- } else {
- def_id
- };
- let generics = tcx.generics_of(outer_def_id);
- // FIXME: miri should be able to eval stuff that doesn't need info
- // from the generics
- if generics.parent_types as usize + generics.types.len() > 0 {
- return;
- }
- for i in 0.. mir.promoted.len() {
- use rustc_data_structures::indexed_vec::Idx;
- let cid = GlobalId {
- instance,
- promoted: Some(Promoted::new(i)),
- };
- eval_body_with_mir(tcx, cid, mir, param_env);
- }
-}
-
-struct ConstErrVisitor<'a, 'tcx: 'a> {
- tcx: TyCtxt<'a, 'tcx, 'tcx>,
- mir: &'a Mir<'tcx>,
-}
-
-impl<'a, 'tcx> ConstErrVisitor<'a, 'tcx> {
- fn eval_op(&self, op: &Operand<'tcx>) -> Option<u128> {
- let op = match *op {
- Operand::Constant(ref c) => c,
- _ => return None,
- };
- match op.literal {
- Literal::Value { value } => match value.val {
- ConstVal::Value(Value::ByVal(PrimVal::Bytes(b))) => Some(b),
- _ => return None,
- },
- _ => None,
- }
- }
-}
-
-impl<'a, 'tcx> Visitor<'tcx> for ConstErrVisitor<'a, 'tcx> {
- fn visit_terminator(&mut self,
- block: BasicBlock,
- terminator: &Terminator<'tcx>,
- location: Location) {
- self.super_terminator(block, terminator, location);
- match terminator.kind {
- TerminatorKind::Assert { ref cond, expected, ref msg, .. } => {
- let cond = match self.eval_op(cond) {
- Some(val) => val,
- None => return,
- };
- if (cond == 1) == expected {
- return;
- }
- assert!(cond <= 1);
- // If we know we always panic, and the error message
- // is also constant, then we can produce a warning.
-
- let kind = match *msg {
- AssertMessage::BoundsCheck { ref len, ref index } => {
- let len = match self.eval_op(len) {
- Some(val) => val,
- None => return,
- };
- let index = match self.eval_op(index) {
- Some(val) => val,
- None => return,
- };
- ErrKind::IndexOutOfBounds {
- len: len as u64,
- index: index as u64
- }
- }
- AssertMessage::Math(ref err) => ErrKind::Math(err.clone()),
- AssertMessage::GeneratorResumedAfterReturn |
- // FIXME(oli-obk): can we report a const_err warning here?
- AssertMessage::GeneratorResumedAfterPanic => return,
- };
- let span = terminator.source_info.span;
- let msg = ConstEvalErr{ span, kind };
- let scope_info = match self.mir.visibility_scope_info {
- ClearCrossCrate::Set(ref data) => data,
- ClearCrossCrate::Clear => return,
- };
- let node_id = scope_info[terminator.source_info.scope].lint_root;
- self.tcx.lint_node(::rustc::lint::builtin::CONST_ERR,
- node_id,
- msg.span,
- &msg.description().into_oneline().into_owned());
- },
- _ => {},
- }
- }
- fn visit_rvalue(&mut self,
- rvalue: &Rvalue<'tcx>,
- location: Location) {
- self.super_rvalue(rvalue, location);
- use rustc::mir::BinOp;
- match *rvalue {
- Rvalue::BinaryOp(BinOp::Shr, ref lop, ref rop) |
- Rvalue::BinaryOp(BinOp::Shl, ref lop, ref rop) => {
- let val = match self.eval_op(rop) {
- Some(val) => val,
- None => return,
- };
- let ty = lop.ty(self.mir, self.tcx);
- let param_env = ParamEnv::empty(traits::Reveal::All);
- let bits = (self.tcx, param_env).layout_of(ty).unwrap().size.bits();
- if val >= bits as u128 {
- let data = &self.mir[location.block];
- let stmt_idx = location.statement_index;
- let source_info = if stmt_idx < data.statements.len() {
- data.statements[stmt_idx].source_info
- } else {
- data.terminator().source_info
- };
- let span = source_info.span;
- let scope_info = match self.mir.visibility_scope_info {
- ClearCrossCrate::Set(ref data) => data,
- ClearCrossCrate::Clear => return,
- };
- let node_id = scope_info[source_info.scope].lint_root;
- self.tcx.lint_node(
- ::rustc::lint::builtin::EXCEEDING_BITSHIFTS,
- node_id,
- span,
- "bitshift exceeds the type's number of bits");
- }
- }
- _ => {}
- }
- }
-}
let instance = Instance::new(self.source.def_id, substs);
let ecx = mk_borrowck_eval_cx(self.tcx, instance, self.mir, span).unwrap();
- let l = ecx.value_to_primval(ValTy { value: left.0, ty: left.1 }).ok()?;
let r = ecx.value_to_primval(ValTy { value: right.0, ty: right.1 }).ok()?;
+ let param_env = ParamEnv::empty(traits::Reveal::All);
+ let bits = (self.tcx, param_env).layout_of(left.ty).unwrap().size.bits();
+ if r >= bits as u128 {
+ let data = &self.mir[location.block];
+ let stmt_idx = location.statement_index;
+ let source_info = if stmt_idx < data.statements.len() {
+ data.statements[stmt_idx].source_info
+ } else {
+ data.terminator().source_info
+ };
+ let span = source_info.span;
+ let scope_info = match self.mir.visibility_scope_info {
+ ClearCrossCrate::Set(ref data) => data,
+ ClearCrossCrate::Clear => return,
+ };
+ let node_id = scope_info[source_info.scope].lint_root;
+ self.tcx.lint_node(
+ ::rustc::lint::builtin::EXCEEDING_BITSHIFTS,
+ node_id,
+ span,
+ "bitshift exceeds the type's number of bits");
+ }
+ let l = ecx.value_to_primval(ValTy { value: left.0, ty: left.1 }).ok()?;
trace!("const evaluating {:?} for {:?} and {:?}", op, left, right);
match ecx.binary_op(op, l, left.1, r, right.1) {
Ok((val, overflow)) => {
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