src/librustc/cfg/graphviz.rs

   1 /// This module provides linkage between rustc::middle::graph and
   2 /// libgraphviz traits.
   3
   4 // For clarity, rename the graphviz crate locally to dot.
   5 use graphviz as dot;
   6
   7 use cfg;
   8 use hir;
   9 use ty::TyCtxt;
  10
  11 pub type Node<'a> = (cfg::CFGIndex, &'a cfg::CFGNode);
  12 pub type Edge<'a> = &'a cfg::CFGEdge;
  13
  14 pub struct LabelledCFG<'a, 'tcx: 'a> {
  15     pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
  16     pub cfg: &'a cfg::CFG,
  17     pub name: String,
  18     /// `labelled_edges` controls whether we emit labels on the edges
  19     pub labelled_edges: bool,
  20 }
  21
  22 impl<'a, 'tcx> LabelledCFG<'a, 'tcx> {
  23     fn local_id_to_string(&self, local_id: hir::ItemLocalId) -> String {
  24         assert!(self.cfg.owner_def_id.is_local());
  25         let node_id = self.tcx.hir().hir_to_node_id(hir::HirId {
  26             owner: self.tcx.hir().def_index_to_hir_id(self.cfg.owner_def_id.index).owner,
  27             local_id
  28         });
  29         let s = self.tcx.hir().node_to_string(node_id);
  30
  31         // Replacing newlines with \\l causes each line to be left-aligned,
  32         // improving presentation of (long) pretty-printed expressions.
  33         if s.contains("\n") {
  34             let mut s = s.replace("\n", "\\l");
  35             // Apparently left-alignment applies to the line that precedes
  36             // \l, not the line that follows; so, add \l at end of string
  37             // if not already present, ensuring last line gets left-aligned
  38             // as well.
  39             let mut last_two: Vec<_> =
  40                 s.chars().rev().take(2).collect();
  41             last_two.reverse();
  42             if last_two != ['\\', 'l'] {
  43                 s.push_str("\\l");
  44             }
  45             s
  46         } else {
  47             s
  48         }
  49     }
  50 }
  51
  52 impl<'a, 'hir> dot::Labeller<'a> for LabelledCFG<'a, 'hir> {
  53     type Node = Node<'a>;
  54     type Edge = Edge<'a>;
  55     fn graph_id(&'a self) -> dot::Id<'a> { dot::Id::new(&self.name[..]).unwrap() }
  56
  57     fn node_id(&'a self, &(i,_): &Node<'a>) -> dot::Id<'a> {
  58         dot::Id::new(format!("N{}", i.node_id())).unwrap()
  59     }
  60
  61     fn node_label(&'a self, &(i, n): &Node<'a>) -> dot::LabelText<'a> {
  62         if i == self.cfg.entry {
  63             dot::LabelText::LabelStr("entry".into())
  64         } else if i == self.cfg.exit {
  65             dot::LabelText::LabelStr("exit".into())
  66         } else if n.data.id() == hir::DUMMY_ITEM_LOCAL_ID {
  67             dot::LabelText::LabelStr("(dummy_node)".into())
  68         } else {
  69             let s = self.local_id_to_string(n.data.id());
  70             dot::LabelText::EscStr(s.into())
  71         }
  72     }
  73
  74     fn edge_label(&self, e: &Edge<'a>) -> dot::LabelText<'a> {
  75         let mut label = String::new();
  76         if !self.labelled_edges {
  77             return dot::LabelText::EscStr(label.into());
  78         }
  79         let mut put_one = false;
  80         for (i, &id) in e.data.exiting_scopes.iter().enumerate() {
  81             if put_one {
  82                 label.push_str(",\\l");
  83             } else {
  84                 put_one = true;
  85             }
  86             let s = self.local_id_to_string(id);
  87             label.push_str(&format!("exiting scope_{} {}",
  88                                    i,
  89                                    &s[..]));
  90         }
  91         dot::LabelText::EscStr(label.into())
  92     }
  93 }
  94
  95 impl<'a> dot::GraphWalk<'a> for &'a cfg::CFG {
  96     type Node = Node<'a>;
  97     type Edge = Edge<'a>;
  98     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> {
  99         let v: Vec<_> = self.graph.enumerated_nodes().collect();
 100         v.into()
 101     }
 102     fn edges(&'a self) -> dot::Edges<'a, Edge<'a>> {
 103         self.graph.all_edges().iter().collect()
 104     }
 105     fn source(&'a self, edge: &Edge<'a>) -> Node<'a> {
 106         let i = edge.source();
 107         (i, self.graph.node(i))
 108     }
 109     fn target(&'a self, edge: &Edge<'a>) -> Node<'a> {
 110         let i = edge.target();
 111         (i, self.graph.node(i))
 112     }
 113 }
 114
 115 impl<'a, 'hir> dot::GraphWalk<'a> for LabelledCFG<'a, 'hir>
 116 {
 117     type Node = Node<'a>;
 118     type Edge = Edge<'a>;
 119     fn nodes(&'a self) -> dot::Nodes<'a, Node<'a>> { self.cfg.nodes() }
 120     fn edges(&'a self) -> dot::Edges<'a, Edge<'a>> { self.cfg.edges() }
 121     fn source(&'a self, edge: &Edge<'a>) -> Node<'a> { self.cfg.source(edge) }
 122     fn target(&'a self, edge: &Edge<'a>) -> Node<'a> { self.cfg.target(edge) }
 123 }