1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! This module provides linkage between libgraphviz traits and
12 //! `rustc::middle::typeck::infer::region_constraints`, generating a
13 //! rendering of the graph represented by the list of `Constraint`
14 //! instances (which make up the edges of the graph), as well as the
15 //! origin for each constraint (which are attached to the labels on
18 /// For clarity, rename the graphviz crate locally to dot.
21 use hir::def_id::DefIndex;
22 use rustc_data_structures::indexed_vec::Idx;
24 use middle::free_region::RegionRelations;
26 use super::Constraint;
27 use infer::SubregionOrigin;
28 use infer::region_constraints::RegionConstraintData;
29 use util::nodemap::{FxHashMap, FxHashSet};
32 use std::collections::hash_map::Entry::Vacant;
33 use std::collections::btree_map::BTreeMap;
37 use std::io::prelude::*;
38 use std::sync::atomic::{AtomicBool, Ordering};
40 fn print_help_message() {
42 -Z print-region-graph by default prints a region constraint graph for every \n\
43 function body, to the path `/tmp/constraints.nodeXXX.dot`, where the XXX is \n\
44 replaced with the node id of the function under analysis. \n\
46 To select one particular function body, set `RUST_REGION_GRAPH_NODE=XXX`, \n\
47 where XXX is the node id desired. \n\
49 To generate output to some path other than the default \n\
50 `/tmp/constraints.nodeXXX.dot`, set `RUST_REGION_GRAPH=/path/desired.dot`; \n\
51 occurrences of the character `%` in the requested path will be replaced with\n\
52 the node id of the function under analysis. \n\
54 (Since you requested help via RUST_REGION_GRAPH=help, no region constraint \n\
55 graphs will be printed. \n\
59 pub fn maybe_print_constraints_for<'a, 'gcx, 'tcx>(
60 region_data: &RegionConstraintData<'tcx>,
61 region_rels: &RegionRelations<'a, 'gcx, 'tcx>)
63 let tcx = region_rels.tcx;
64 let context = region_rels.context;
66 if !tcx.sess.opts.debugging_opts.print_region_graph {
70 let requested_node = env::var("RUST_REGION_GRAPH_NODE")
71 .ok().and_then(|s| s.parse().map(DefIndex::new).ok());
73 if requested_node.is_some() && requested_node != Some(context.index) {
77 let requested_output = env::var("RUST_REGION_GRAPH");
78 debug!("requested_output: {:?} requested_node: {:?}",
83 let output_template = match requested_output {
84 Ok(ref s) if s == "help" => {
85 static PRINTED_YET: AtomicBool = AtomicBool::new(false);
86 if !PRINTED_YET.load(Ordering::SeqCst) {
88 PRINTED_YET.store(true, Ordering::SeqCst);
93 Ok(other_path) => other_path,
94 Err(_) => "/tmp/constraints.node%.dot".to_string(),
97 if output_template.is_empty() {
98 panic!("empty string provided as RUST_REGION_GRAPH");
101 if output_template.contains('%') {
102 let mut new_str = String::new();
103 for c in output_template.chars() {
105 new_str.push_str(&context.index.as_usize().to_string());
116 match dump_region_data_to(region_rels, ®ion_data.constraints, &output_path) {
119 let msg = format!("io error dumping region constraints: {}", e);
125 struct ConstraintGraph<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
127 region_rels: &'a RegionRelations<'a, 'gcx, 'tcx>,
128 map: &'a BTreeMap<Constraint<'tcx>, SubregionOrigin<'tcx>>,
129 node_ids: FxHashMap<Node, usize>,
132 #[derive(Clone, Hash, PartialEq, Eq, Debug, Copy)]
134 RegionVid(ty::RegionVid),
135 Region(ty::RegionKind),
138 #[derive(Clone, PartialEq, Eq, Debug, Copy)]
140 Constraint(Constraint<'tcx>),
141 EnclScope(region::Scope, region::Scope),
144 impl<'a, 'gcx, 'tcx> ConstraintGraph<'a, 'gcx, 'tcx> {
146 region_rels: &'a RegionRelations<'a, 'gcx, 'tcx>,
147 map: &'a ConstraintMap<'tcx>)
148 -> ConstraintGraph<'a, 'gcx, 'tcx> {
150 let mut node_ids = FxHashMap();
152 let mut add_node = |node| {
153 if let Vacant(e) = node_ids.entry(node) {
159 for (n1, n2) in map.keys().map(|c| constraint_to_nodes(c)) {
164 region_rels.region_scope_tree.each_encl_scope(|sub, sup| {
165 add_node(Node::Region(ty::ReScope(sub)));
166 add_node(Node::Region(ty::ReScope(sup)));
179 impl<'a, 'gcx, 'tcx> dot::Labeller<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
181 type Edge = Edge<'tcx>;
182 fn graph_id(&self) -> dot::Id {
183 dot::Id::new(&*self.graph_name).unwrap()
185 fn node_id(&self, n: &Node) -> dot::Id {
186 let node_id = match self.node_ids.get(n) {
187 Some(node_id) => node_id,
188 None => bug!("no node_id found for node: {:?}", n),
190 let name = || format!("node_{}", node_id);
191 match dot::Id::new(name()) {
194 bug!("failed to create graphviz node identified by {}", name());
198 fn node_label(&self, n: &Node) -> dot::LabelText {
200 Node::RegionVid(n_vid) => dot::LabelText::label(format!("{:?}", n_vid)),
201 Node::Region(n_rgn) => dot::LabelText::label(format!("{:?}", n_rgn)),
204 fn edge_label(&self, e: &Edge) -> dot::LabelText {
206 Edge::Constraint(ref c) =>
207 dot::LabelText::label(format!("{:?}", self.map.get(c).unwrap())),
208 Edge::EnclScope(..) => dot::LabelText::label(format!("(enclosed)")),
213 fn constraint_to_nodes(c: &Constraint) -> (Node, Node) {
215 Constraint::VarSubVar(rv_1, rv_2) =>
216 (Node::RegionVid(rv_1), Node::RegionVid(rv_2)),
217 Constraint::RegSubVar(r_1, rv_2) =>
218 (Node::Region(*r_1), Node::RegionVid(rv_2)),
219 Constraint::VarSubReg(rv_1, r_2) =>
220 (Node::RegionVid(rv_1), Node::Region(*r_2)),
221 Constraint::RegSubReg(r_1, r_2) =>
222 (Node::Region(*r_1), Node::Region(*r_2)),
226 fn edge_to_nodes(e: &Edge) -> (Node, Node) {
228 Edge::Constraint(ref c) => constraint_to_nodes(c),
229 Edge::EnclScope(sub, sup) => {
230 (Node::Region(ty::ReScope(sub)),
231 Node::Region(ty::ReScope(sup)))
236 impl<'a, 'gcx, 'tcx> dot::GraphWalk<'a> for ConstraintGraph<'a, 'gcx, 'tcx> {
238 type Edge = Edge<'tcx>;
239 fn nodes(&self) -> dot::Nodes<Node> {
240 let mut set = FxHashSet();
241 for node in self.node_ids.keys() {
244 debug!("constraint graph has {} nodes", set.len());
245 set.into_iter().collect()
247 fn edges(&self) -> dot::Edges<Edge<'tcx>> {
248 debug!("constraint graph has {} edges", self.map.len());
249 let mut v: Vec<_> = self.map.keys().map(|e| Edge::Constraint(*e)).collect();
250 self.region_rels.region_scope_tree.each_encl_scope(|sub, sup| {
251 v.push(Edge::EnclScope(sub, sup))
253 debug!("region graph has {} edges", v.len());
256 fn source(&self, edge: &Edge<'tcx>) -> Node {
257 let (n1, _) = edge_to_nodes(edge);
258 debug!("edge {:?} has source {:?}", edge, n1);
261 fn target(&self, edge: &Edge<'tcx>) -> Node {
262 let (_, n2) = edge_to_nodes(edge);
263 debug!("edge {:?} has target {:?}", edge, n2);
268 pub type ConstraintMap<'tcx> = BTreeMap<Constraint<'tcx>, SubregionOrigin<'tcx>>;
270 fn dump_region_data_to<'a, 'gcx, 'tcx>(region_rels: &RegionRelations<'a, 'gcx, 'tcx>,
271 map: &ConstraintMap<'tcx>,
274 debug!("dump_region_data map (len: {}) path: {}",
277 let g = ConstraintGraph::new(format!("region_data"), region_rels, map);
278 debug!("dump_region_data calling render");
279 let mut v = Vec::new();
280 dot::render(&g, &mut v).unwrap();
281 File::create(path).and_then(|mut f| f.write_all(&v))