// Copyright 2015 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.
//! An experimental pass that scources for `#[rustc_mir]` attributes,
//! builds the resulting MIR, and dumps it out into a file for inspection.
//!
//! The attribute formats that are currently accepted are:
//!
//! - `#[rustc_mir(graphviz="file.gv")]`
//! - `#[rustc_mir(pretty="file.mir")]`
extern crate syntax;
extern crate rustc;
extern crate rustc_front;
use build;
use dot;
use transform::*;
use repr::Mir;
use hair::cx::Cx;
use std::fs::File;
use self::rustc::middle::infer;
use self::rustc::middle::region::CodeExtentData;
use self::rustc::middle::ty::{self, Ty};
use self::rustc::util::common::ErrorReported;
use self::rustc::util::nodemap::NodeMap;
use self::rustc_front::hir;
use self::rustc_front::intravisit::{self, Visitor};
use self::syntax::ast;
use self::syntax::attr::AttrMetaMethods;
use self::syntax::codemap::Span;
pub type MirMap<'tcx> = NodeMap<Mir<'tcx>>;
pub fn build_mir_for_crate<'tcx>(tcx: &ty::ctxt<'tcx>) -> MirMap<'tcx> {
let mut map = NodeMap();
{
let mut dump = OuterDump {
tcx: tcx,
map: &mut map,
};
tcx.map.krate().visit_all_items(&mut dump);
}
map
}
///////////////////////////////////////////////////////////////////////////
// OuterDump -- walks a crate, looking for fn items and methods to build MIR from
struct OuterDump<'a, 'tcx: 'a> {
tcx: &'a ty::ctxt<'tcx>,
map: &'a mut MirMap<'tcx>,
}
impl<'a, 'tcx> OuterDump<'a, 'tcx> {
fn visit_mir<OP>(&mut self, attributes: &'a [ast::Attribute], mut walk_op: OP)
where OP: for<'m> FnMut(&mut InnerDump<'a, 'm, 'tcx>)
{
let mut closure_dump = InnerDump {
tcx: self.tcx,
attr: None,
map: &mut *self.map,
};
for attr in attributes {
if attr.check_name("rustc_mir") {
closure_dump.attr = Some(attr);
}
}
walk_op(&mut closure_dump);
}
}
impl<'a, 'tcx> Visitor<'tcx> for OuterDump<'a, 'tcx> {
fn visit_item(&mut self, item: &'tcx hir::Item) {
self.visit_mir(&item.attrs, |c| intravisit::walk_item(c, item));
intravisit::walk_item(self, item);
}
fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) {
match trait_item.node {
hir::MethodTraitItem(_, Some(_)) => {
self.visit_mir(&trait_item.attrs, |c| intravisit::walk_trait_item(c, trait_item));
}
hir::MethodTraitItem(_, None) |
hir::ConstTraitItem(..) |
hir::TypeTraitItem(..) => {}
}
intravisit::walk_trait_item(self, trait_item);
}
fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
match impl_item.node {
hir::ImplItemKind::Method(..) => {
self.visit_mir(&impl_item.attrs, |c| intravisit::walk_impl_item(c, impl_item));
}
hir::ImplItemKind::Const(..) | hir::ImplItemKind::Type(..) => {}
}
intravisit::walk_impl_item(self, impl_item);
}
}
///////////////////////////////////////////////////////////////////////////
// InnerDump -- dumps MIR for a single fn and its contained closures
struct InnerDump<'a, 'm, 'tcx: 'a + 'm> {
tcx: &'a ty::ctxt<'tcx>,
map: &'m mut MirMap<'tcx>,
attr: Option<&'a ast::Attribute>,
}
impl<'a, 'm, 'tcx> Visitor<'tcx> for InnerDump<'a,'m,'tcx> {
fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem) {
// ignore methods; the outer dump will call us for them independently
}
fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem) {
// ignore methods; the outer dump will call us for them independently
}
fn visit_fn(&mut self,
fk: intravisit::FnKind<'tcx>,
decl: &'tcx hir::FnDecl,
body: &'tcx hir::Block,
span: Span,
id: ast::NodeId) {
let (prefix, implicit_arg_tys) = match fk {
intravisit::FnKind::Closure =>
(format!("{}-", id), vec![closure_self_ty(&self.tcx, id, body.id)]),
_ =>
(format!(""), vec![]),
};
let param_env = ty::ParameterEnvironment::for_item(self.tcx, id);
let infcx = infer::new_infer_ctxt(self.tcx, &self.tcx.tables, Some(param_env), true);
match build_mir(Cx::new(&infcx), implicit_arg_tys, id, span, decl, body) {
Ok(mut mir) => {
simplify_cfg::SimplifyCfg::new().run_on_mir(&mut mir);
let meta_item_list = self.attr
.iter()
.flat_map(|a| a.meta_item_list())
.flat_map(|l| l.iter());
for item in meta_item_list {
if item.check_name("graphviz") {
match item.value_str() {
Some(s) => {
match
File::create(format!("{}{}", prefix, s))
.and_then(|ref mut output| dot::render(&mir, output))
{
Ok(()) => { }
Err(e) => {
self.tcx.sess.span_fatal(
item.span,
&format!("Error writing graphviz \
results to `{}`: {}",
s, e));
}
}
}
None => {
self.tcx.sess.span_err(
item.span,
"graphviz attribute requires a path");
}
}
}
}
let previous = self.map.insert(id, mir);
assert!(previous.is_none());
}
Err(ErrorReported) => {}
}
intravisit::walk_fn(self, fk, decl, body, span);
}
}
fn build_mir<'a,'tcx:'a>(cx: Cx<'a,'tcx>,
implicit_arg_tys: Vec<Ty<'tcx>>,
fn_id: ast::NodeId,
span: Span,
decl: &'tcx hir::FnDecl,
body: &'tcx hir::Block)
-> Result<Mir<'tcx>, ErrorReported> {
// fetch the fully liberated fn signature (that is, all bound
// types/lifetimes replaced)
let fn_sig = match cx.tcx().tables.borrow().liberated_fn_sigs.get(&fn_id) {
Some(f) => f.clone(),
None => {
cx.tcx().sess.span_bug(span,
&format!("no liberated fn sig for {:?}", fn_id));
}
};
let arguments =
decl.inputs
.iter()
.enumerate()
.map(|(index, arg)| {
(fn_sig.inputs[index], &*arg.pat)
})
.collect();
let parameter_scope =
cx.tcx().region_maps.lookup_code_extent(
CodeExtentData::ParameterScope { fn_id: fn_id, body_id: body.id });
Ok(build::construct(cx,
span,
implicit_arg_tys,
arguments,
parameter_scope,
fn_sig.output,
body))
}
fn closure_self_ty<'a, 'tcx>(tcx: &ty::ctxt<'tcx>,
closure_expr_id: ast::NodeId,
body_id: ast::NodeId)
-> Ty<'tcx> {
let closure_ty = tcx.node_id_to_type(closure_expr_id);
// We're just hard-coding the idea that the signature will be
// &self or &mut self and hence will have a bound region with
// number 0, hokey.
let region = ty::Region::ReFree(ty::FreeRegion {
scope: tcx.region_maps.item_extent(body_id),
bound_region: ty::BoundRegion::BrAnon(0),
});
let region = tcx.mk_region(region);
match tcx.closure_kind(tcx.map.local_def_id(closure_expr_id)) {
ty::ClosureKind::FnClosureKind =>
tcx.mk_ref(region,
ty::TypeAndMut { ty: closure_ty,
mutbl: hir::MutImmutable }),
ty::ClosureKind::FnMutClosureKind =>
tcx.mk_ref(region,
ty::TypeAndMut { ty: closure_ty,
mutbl: hir::MutMutable }),
ty::ClosureKind::FnOnceClosureKind =>
closure_ty
}
}