src/librustc_borrowck/graphviz.rs

   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.
   4 //
   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.
  10
  11 //! This module provides linkage between rustc::middle::graph and
  12 //! libgraphviz traits, specialized to attaching borrowck analysis
  13 //! data to rendered labels.
  14
  15 pub use self::Variant::*;
  16
  17 pub use rustc::cfg::graphviz::{Node, Edge};
  18 use rustc::cfg::graphviz as cfg_dot;
  19
  20 use borrowck;
  21 use borrowck::{BorrowckCtxt, LoanPath};
  22 use dot;
  23 use rustc::cfg::CFGIndex;
  24 use rustc::middle::dataflow::{DataFlowOperator, DataFlowContext, EntryOrExit};
  25 use std::rc::Rc;
  26 use dot::IntoCow;
  27
  28 #[derive(Debug, Copy, Clone)]
  29 pub enum Variant {
  30     Loans,
  31     Moves,
  32     Assigns,
  33 }
  34
  35 impl Variant {
  36     pub fn short_name(&self) -> &'static str {
  37         match *self {
  38             Loans   => "loans",
  39             Moves   => "moves",
  40             Assigns => "assigns",
  41         }
  42     }
  43 }
  44
  45 pub struct DataflowLabeller<'a, 'tcx: 'a> {
  46     pub inner: cfg_dot::LabelledCFG<'a, 'tcx>,
  47     pub variants: Vec<Variant>,
  48     pub borrowck_ctxt: &'a BorrowckCtxt<'a, 'tcx>,
  49     pub analysis_data: &'a borrowck::AnalysisData<'a, 'tcx>,
  50 }
  51
  52 impl<'a, 'tcx> DataflowLabeller<'a, 'tcx> {
  53     fn dataflow_for(&self, e: EntryOrExit, n: &Node<'a>) -> String {
  54         let id = n.1.data.id();
  55         debug!("dataflow_for({:?}, id={}) {:?}", e, id, self.variants);
  56         let mut sets = "".to_string();
  57         let mut seen_one = false;
  58         for &variant in &self.variants {
  59             if seen_one { sets.push_str(" "); } else { seen_one = true; }
  60             sets.push_str(variant.short_name());
  61             sets.push_str(": ");
  62             sets.push_str(&self.dataflow_for_variant(e, n, variant));
  63         }
  64         sets
  65     }
  66
  67     fn dataflow_for_variant(&self, e: EntryOrExit, n: &Node, v: Variant) -> String {
  68         let cfgidx = n.0;
  69         match v {
  70             Loans   => self.dataflow_loans_for(e, cfgidx),
  71             Moves   => self.dataflow_moves_for(e, cfgidx),
  72             Assigns => self.dataflow_assigns_for(e, cfgidx),
  73         }
  74     }
  75
  76     fn build_set<O:DataFlowOperator, F>(&self,
  77                                         e: EntryOrExit,
  78                                         cfgidx: CFGIndex,
  79                                         dfcx: &DataFlowContext<'a, 'tcx, O>,
  80                                         mut to_lp: F) -> String where
  81         F: FnMut(usize) -> Rc<LoanPath<'tcx>>,
  82     {
  83         let mut saw_some = false;
  84         let mut set = "{".to_string();
  85         dfcx.each_bit_for_node(e, cfgidx, |index| {
  86             let lp = to_lp(index);
  87             if saw_some {
  88                 set.push_str(", ");
  89             }
  90             let loan_str = self.borrowck_ctxt.loan_path_to_string(&lp);
  91             set.push_str(&loan_str[..]);
  92             saw_some = true;
  93             true
  94         });
  95         set.push_str("}");
  96         set
  97     }
  98
  99     fn dataflow_loans_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
 100         let dfcx = &self.analysis_data.loans;
 101         let loan_index_to_path = |loan_index| {
 102             let all_loans = &self.analysis_data.all_loans;
 103             let l: &borrowck::Loan = &all_loans[loan_index];
 104             l.loan_path()
 105         };
 106         self.build_set(e, cfgidx, dfcx, loan_index_to_path)
 107     }
 108
 109     fn dataflow_moves_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
 110         let dfcx = &self.analysis_data.move_data.dfcx_moves;
 111         let move_index_to_path = |move_index| {
 112             let move_data = &self.analysis_data.move_data.move_data;
 113             let moves = move_data.moves.borrow();
 114             let the_move: &borrowck::move_data::Move = &(*moves)[move_index];
 115             move_data.path_loan_path(the_move.path)
 116         };
 117         self.build_set(e, cfgidx, dfcx, move_index_to_path)
 118     }
 119
 120     fn dataflow_assigns_for(&self, e: EntryOrExit, cfgidx: CFGIndex) -> String {
 121         let dfcx = &self.analysis_data.move_data.dfcx_assign;
 122         let assign_index_to_path = |assign_index| {
 123             let move_data = &self.analysis_data.move_data.move_data;
 124             let assignments = move_data.var_assignments.borrow();
 125             let assignment: &borrowck::move_data::Assignment = &(*assignments)[assign_index];
 126             move_data.path_loan_path(assignment.path)
 127         };
 128         self.build_set(e, cfgidx, dfcx, assign_index_to_path)
 129     }
 130 }
 131
 132 impl<'a, 'tcx> dot::Labeller<'a> for DataflowLabeller<'a, 'tcx> {
 133     type Node = Node<'a>;
 134     type Edge = Edge<'a>;
 135     fn graph_id(&'a self) -> dot::Id<'a> { self.inner.graph_id() }
 136     fn node_id(&'a self, n: &Node<'a>) -> dot::Id<'a> { self.inner.node_id(n) }
 137     fn node_label(&'a self, n: &Node<'a>) -> dot::LabelText<'a> {
 138         let prefix = self.dataflow_for(EntryOrExit::Entry, n);
 139         let suffix = self.dataflow_for(EntryOrExit::Exit, n);
 140         let inner_label = self.inner.node_label(n);
 141         inner_label
 142             .prefix_line(dot::LabelText::LabelStr(prefix.into_cow()))
 143             .suffix_line(dot::LabelText::LabelStr(suffix.into_cow()))
 144     }
 145     fn edge_label(&'a self, e: &Edge<'a>) -> dot::LabelText<'a> { self.inner.edge_label(e) }
 146 }
 147
 148 impl<'a, 'tcx> dot::GraphWalk<'a> for DataflowLabeller<'a, 'tcx> {
 149     type Node = Node<'a>;
 150     type Edge = Edge<'a>;
 151     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> { self.inner.nodes() }
 152     fn edges(&'a self) -> dot::Edges<'a, Edge<'a>> { self.inner.edges() }
 153     fn source(&'a self, edge: &Edge<'a>) -> Node<'a> { self.inner.source(edge) }
 154     fn target(&'a self, edge: &Edge<'a>) -> Node<'a> { self.inner.target(edge) }
 155 }