1 // Copyright 2012-2016 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 //! Hook into libgraphviz for rendering dataflow graphs for MIR.
13 use syntax::ast::NodeId;
14 use rustc::mir::{BasicBlock, Mir};
15 use rustc_data_structures::bitslice::bits_to_string;
16 use rustc_data_structures::indexed_set::{IdxSet};
17 use rustc_data_structures::indexed_vec::Idx;
25 use std::io::prelude::*;
26 use std::marker::PhantomData;
30 use super::super::MirBorrowckCtxtPreDataflow;
31 use super::{BitDenotation, DataflowState};
33 impl<O: BitDenotation> DataflowState<O> {
34 fn each_bit<F>(&self, words: &IdxSet<O::Idx>, mut f: F)
35 where F: FnMut(O::Idx) {
36 //! Helper for iterating over the bits in a bitvector.
38 let bits_per_block = self.operator.bits_per_block();
39 let usize_bits: usize = mem::size_of::<usize>() * 8;
41 for (word_index, &word) in words.words().iter().enumerate() {
43 let base_index = word_index * usize_bits;
44 for offset in 0..usize_bits {
45 let bit = 1 << offset;
46 if (word & bit) != 0 {
47 // NB: we round up the total number of bits
48 // that we store in any given bit set so that
49 // it is an even multiple of usize::BITS. This
50 // means that there may be some stray bits at
51 // the end that do not correspond to any
52 // actual value; that's why we first check
53 // that we are in range of bits_per_block.
54 let bit_index = base_index + offset as usize;
55 if bit_index >= bits_per_block {
58 f(O::Idx::new(bit_index));
66 pub fn interpret_set<'c, P>(&self,
68 words: &IdxSet<O::Idx>,
71 where P: Fn(&O, O::Idx) -> &Debug
73 let mut v = Vec::new();
74 self.each_bit(words, |i| {
75 v.push(render_idx(o, i));
81 pub trait MirWithFlowState<'tcx> {
82 type BD: BitDenotation;
83 fn node_id(&self) -> NodeId;
84 fn mir(&self) -> &Mir<'tcx>;
85 fn flow_state(&self) -> &DataflowState<Self::BD>;
88 impl<'a, 'tcx: 'a, BD> MirWithFlowState<'tcx> for MirBorrowckCtxtPreDataflow<'a, 'tcx, BD>
89 where 'tcx: 'a, BD: BitDenotation
92 fn node_id(&self) -> NodeId { self.node_id }
93 fn mir(&self) -> &Mir<'tcx> { self.flow_state.mir() }
94 fn flow_state(&self) -> &DataflowState<Self::BD> { &self.flow_state.flow_state }
97 struct Graph<'a, 'tcx, MWF:'a, P> where
98 MWF: MirWithFlowState<'tcx>
101 phantom: PhantomData<&'tcx ()>,
105 pub fn print_borrowck_graph_to<'a, 'tcx, BD, P>(
106 mbcx: &MirBorrowckCtxtPreDataflow<'a, 'tcx, BD>,
110 where BD: BitDenotation,
111 P: Fn(&BD, BD::Idx) -> &Debug
113 let g = Graph { mbcx: mbcx, phantom: PhantomData, render_idx: render_idx };
114 let mut v = Vec::new();
115 dot::render(&g, &mut v)?;
116 debug!("print_borrowck_graph_to path: {} node_id: {}",
117 path.display(), mbcx.node_id);
118 File::create(path).and_then(|mut f| f.write_all(&v))
121 pub type Node = BasicBlock;
123 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
124 pub struct Edge { source: BasicBlock, index: usize }
126 fn outgoing(mir: &Mir, bb: BasicBlock) -> Vec<Edge> {
127 let succ_len = mir[bb].terminator().successors().len();
128 (0..succ_len).map(|index| Edge { source: bb, index: index}).collect()
131 impl<'a, 'tcx, MWF, P> dot::Labeller<'a> for Graph<'a, 'tcx, MWF, P>
132 where MWF: MirWithFlowState<'tcx>,
133 P: for <'b> Fn(&'b MWF::BD, <MWF::BD as BitDenotation>::Idx) -> &'b Debug,
137 fn graph_id(&self) -> dot::Id {
138 dot::Id::new(format!("graph_for_node_{}",
139 self.mbcx.node_id()))
143 fn node_id(&self, n: &Node) -> dot::Id {
144 dot::Id::new(format!("bb_{}", n.index()))
148 fn node_label(&self, n: &Node) -> dot::LabelText {
149 // A standard MIR label, as generated by write_node_label, is
150 // presented in a single column in a table.
152 // The code below does a bunch of formatting work to format a
153 // node (i.e. MIR basic-block) label with extra
154 // dataflow-enriched information. In particular, the goal is
155 // to add extra columns that present the three dataflow
156 // bitvectors, and the data those bitvectors represent.
158 // It presents it in the following format (where I am
159 // presenting the table rendering via ASCII art, one line per
160 // row of the table, and a chunk size of 3 rather than 5):
162 // ------ ----------------------- ------------ --------------------
164 // [e8, e9] "= ENTRY:" <ENTRY-BITS>
165 // ------ ----------------------- ------------ --------------------
176 // ------ ----------------------- ------------ --------------------
177 // [g1, g4, g5] "= GEN:" <GEN-BITS>
178 // ------ ----------------------- ------------ --------------------
179 // "KILL:" <KILL-BITS> "=" [k1, k3, k8]
181 // ------ ----------------------- ------------ --------------------
183 // (In addition, the added dataflow is rendered with a colored
184 // background just so it will stand out compared to the
186 let mut v = Vec::new();
189 const BG_FLOWCONTENT: &'static str = r#"bgcolor="pink""#;
190 const ALIGN_RIGHT: &'static str = r#"align="right""#;
191 const FACE_MONOSPACE: &'static str = r#"FACE="Courier""#;
192 fn chunked_present_left<W:io::Write>(w: &mut W,
193 interpreted: &[&Debug],
197 // This function may emit a sequence of <tr>'s, but it
198 // always finishes with an (unfinished)
201 // Thus, after being called, one should finish both the
202 // pending <td> as well as the <tr> itself.
203 let mut seen_one = false;
204 for c in interpreted.chunks(chunk_size) {
206 // if not the first row, finish off the previous row
207 write!(w, "</td><td></td><td></td></tr>")?;
209 write!(w, "<tr><td></td><td {bg} {align}>{objs:?}",
216 write!(w, "<tr><td></td><td {bg} {align}>[]",
218 align = ALIGN_RIGHT)?;
222 ::rustc_mir::graphviz::write_node_label(
223 *n, self.mbcx.mir(), &mut v, 4,
225 let flow = self.mbcx.flow_state();
226 let entry_interp = flow.interpret_set(&flow.operator,
227 flow.sets.on_entry_set_for(i),
229 chunked_present_left(w, &entry_interp[..], chunk_size)?;
230 let bits_per_block = flow.sets.bits_per_block();
231 let entry = flow.sets.on_entry_set_for(i);
232 debug!("entry set for i={i} bits_per_block: {bpb} entry: {e:?} interp: {ei:?}",
233 i=i, e=entry, bpb=bits_per_block, ei=entry_interp);
234 write!(w, "= ENTRY:</td><td {bg}><FONT {face}>{entrybits:?}</FONT></td>\
237 face = FACE_MONOSPACE,
238 entrybits=bits_to_string(entry.words(), bits_per_block))
241 let flow = self.mbcx.flow_state();
243 flow.interpret_set(&flow.operator, flow.sets.gen_set_for(i), &self.render_idx);
245 flow.interpret_set(&flow.operator, flow.sets.kill_set_for(i), &self.render_idx);
246 chunked_present_left(w, &gen_interp[..], chunk_size)?;
247 let bits_per_block = flow.sets.bits_per_block();
249 let gen = flow.sets.gen_set_for(i);
250 debug!("gen set for i={i} bits_per_block: {bpb} gen: {g:?} interp: {gi:?}",
251 i=i, g=gen, bpb=bits_per_block, gi=gen_interp);
252 write!(w, " = GEN:</td><td {bg}><FONT {face}>{genbits:?}</FONT></td>\
255 face = FACE_MONOSPACE,
256 genbits=bits_to_string(gen.words(), bits_per_block))?;
260 let kill = flow.sets.kill_set_for(i);
261 debug!("kill set for i={i} bits_per_block: {bpb} kill: {k:?} interp: {ki:?}",
262 i=i, k=kill, bpb=bits_per_block, ki=kill_interp);
263 write!(w, "<tr><td></td><td {bg} {align}>KILL:</td>\
264 <td {bg}><FONT {face}>{killbits:?}</FONT></td>",
267 face = FACE_MONOSPACE,
268 killbits=bits_to_string(kill.words(), bits_per_block))?;
271 // (chunked_present_right)
272 let mut seen_one = false;
273 for k in kill_interp.chunks(chunk_size) {
275 // continuation of row; this is fourth <td>
276 write!(w, "<td {bg}>= {kill:?}</td></tr>",
280 // new row, with indent of three <td>'s
281 write!(w, "<tr><td></td><td></td><td></td><td {bg}>{kill:?}</td></tr>",
288 write!(w, "<td {bg}>= []</td></tr>",
289 bg = BG_FLOWCONTENT)?;
295 dot::LabelText::html(String::from_utf8(v).unwrap())
298 fn node_shape(&self, _n: &Node) -> Option<dot::LabelText> {
299 Some(dot::LabelText::label("none"))
303 impl<'a, 'tcx, MWF, P> dot::GraphWalk<'a> for Graph<'a, 'tcx, MWF, P>
304 where MWF: MirWithFlowState<'tcx>
308 fn nodes(&self) -> dot::Nodes<Node> {
316 fn edges(&self) -> dot::Edges<Edge> {
317 let mir = self.mbcx.mir();
318 // base initial capacity on assumption every block has at
319 // least one outgoing edge (Which should be true for all
320 // blocks but one, the exit-block).
321 let mut edges = Vec::with_capacity(mir.basic_blocks().len());
322 for bb in mir.basic_blocks().indices() {
323 let outgoing = outgoing(mir, bb);
324 edges.extend(outgoing.into_iter());
329 fn source(&self, edge: &Edge) -> Node {
333 fn target(&self, edge: &Edge) -> Node {
334 let mir = self.mbcx.mir();
335 mir[edge.source].terminator().successors()[edge.index]