rust/src/librustc_passes/rvalues.rs

113 lines
3.8 KiB
Rust

// Copyright 2014 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.
// Checks that all rvalues in a crate have statically known size. check_crate
// is the public starting point.
use rustc::dep_graph::DepNode;
use rustc::middle::expr_use_visitor as euv;
use rustc::middle::mem_categorization as mc;
use rustc::ty::{self, TyCtxt, ParameterEnvironment};
use rustc::traits::Reveal;
use rustc::hir;
use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
use syntax::ast;
use syntax_pos::Span;
pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
let mut rvcx = RvalueContext { tcx: tcx };
tcx.visit_all_item_likes_in_krate(DepNode::RvalueCheck, &mut rvcx.as_deep_visitor());
}
struct RvalueContext<'a, 'tcx: 'a> {
tcx: TyCtxt<'a, 'tcx, 'tcx>,
}
impl<'a, 'tcx> Visitor<'tcx> for RvalueContext<'a, 'tcx> {
fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
NestedVisitorMap::OnlyBodies(&self.tcx.map)
}
fn visit_fn(&mut self,
fk: intravisit::FnKind<'tcx>,
fd: &'tcx hir::FnDecl,
b: hir::ExprId,
s: Span,
fn_id: ast::NodeId) {
// FIXME (@jroesch) change this to be an inference context
let param_env = ParameterEnvironment::for_item(self.tcx, fn_id);
self.tcx.infer_ctxt(None, Some(param_env.clone()),
Reveal::NotSpecializable).enter(|infcx| {
let mut delegate = RvalueContextDelegate {
tcx: infcx.tcx,
param_env: &param_env
};
let body = infcx.tcx.map.expr(b);
let mut euv = euv::ExprUseVisitor::new(&mut delegate, &infcx);
euv.walk_fn(fd, body);
});
intravisit::walk_fn(self, fk, fd, b, s, fn_id)
}
}
struct RvalueContextDelegate<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
tcx: TyCtxt<'a, 'gcx, 'tcx>,
param_env: &'a ty::ParameterEnvironment<'gcx>,
}
impl<'a, 'gcx, 'tcx> euv::Delegate<'tcx> for RvalueContextDelegate<'a, 'gcx, 'tcx> {
fn consume(&mut self,
_: ast::NodeId,
span: Span,
cmt: mc::cmt<'tcx>,
_: euv::ConsumeMode) {
debug!("consume; cmt: {:?}; type: {:?}", *cmt, cmt.ty);
let ty = self.tcx.lift_to_global(&cmt.ty).unwrap();
if !ty.is_sized(self.tcx.global_tcx(), self.param_env, span) {
span_err!(self.tcx.sess, span, E0161,
"cannot move a value of type {0}: the size of {0} cannot be statically determined",
ty);
}
}
fn matched_pat(&mut self,
_matched_pat: &hir::Pat,
_cmt: mc::cmt,
_mode: euv::MatchMode) {}
fn consume_pat(&mut self,
_consume_pat: &hir::Pat,
_cmt: mc::cmt,
_mode: euv::ConsumeMode) {
}
fn borrow(&mut self,
_borrow_id: ast::NodeId,
_borrow_span: Span,
_cmt: mc::cmt,
_loan_region: &'tcx ty::Region,
_bk: ty::BorrowKind,
_loan_cause: euv::LoanCause) {
}
fn decl_without_init(&mut self,
_id: ast::NodeId,
_span: Span) {
}
fn mutate(&mut self,
_assignment_id: ast::NodeId,
_assignment_span: Span,
_assignee_cmt: mc::cmt,
_mode: euv::MutateMode) {
}
}