compiler/rustc_mir/src/util/generic_graph.rs

   1 use gsgdt::{Edge, Graph, Node, NodeStyle};
   2 use rustc_hir::def_id::DefId;
   3 use rustc_index::vec::Idx;
   4 use rustc_middle::mir::*;
   5 use rustc_middle::ty::TyCtxt;
   6
   7 /// Convert an MIR function into a gsgdt Graph
   8 pub fn mir_fn_to_generic_graph<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'_>) -> Graph {
   9     let def_id = body.source.def_id();
  10     let def_name = graphviz_safe_def_name(def_id);
  11     let graph_name = format!("Mir_{}", def_name);
  12     let dark_mode = tcx.sess.opts.debugging_opts.graphviz_dark_mode;
  13
  14     // Nodes
  15     let nodes: Vec<Node> = body
  16         .basic_blocks()
  17         .iter_enumerated()
  18         .map(|(block, _)| bb_to_graph_node(block, body, dark_mode))
  19         .collect();
  20
  21     // Edges
  22     let mut edges = Vec::new();
  23     for (source, _) in body.basic_blocks().iter_enumerated() {
  24         let def_id = body.source.def_id();
  25         let terminator = body[source].terminator();
  26         let labels = terminator.kind.fmt_successor_labels();
  27
  28         for (&target, label) in terminator.successors().zip(labels) {
  29             let src = node(def_id, source);
  30             let trg = node(def_id, target);
  31             edges.push(Edge::new(src, trg, label.to_string()));
  32         }
  33     }
  34
  35     Graph::new(graph_name, nodes, edges)
  36 }
  37
  38 fn bb_to_graph_node(block: BasicBlock, body: &Body<'_>, dark_mode: bool) -> Node {
  39     let def_id = body.source.def_id();
  40     let data = &body[block];
  41     let label = node(def_id, block);
  42
  43     let (title, bgcolor) = if data.is_cleanup {
  44         let color = if dark_mode { "royalblue" } else { "lightblue" };
  45         (format!("{} (cleanup)", block.index()), color)
  46     } else {
  47         let color = if dark_mode { "dimgray" } else { "gray" };
  48         (format!("{}", block.index()), color)
  49     };
  50
  51     let style = NodeStyle { title_bg: Some(bgcolor.to_owned()), ..Default::default() };
  52     let mut stmts: Vec<String> = data.statements.iter().map(|x| format!("{:?}", x)).collect();
  53
  54     // add the terminator to the stmts, gsgdt can print it out seperately
  55     let mut terminator_head = String::new();
  56     data.terminator().kind.fmt_head(&mut terminator_head).unwrap();
  57     stmts.push(terminator_head);
  58
  59     Node::new(stmts, label, title, style)
  60 }
  61
  62 // Must match `[0-9A-Za-z_]*`. This does not appear in the rendered graph, so
  63 // it does not have to be user friendly.
  64 pub fn graphviz_safe_def_name(def_id: DefId) -> String {
  65     format!("{}_{}", def_id.krate.index(), def_id.index.index(),)
  66 }
  67
  68 fn node(def_id: DefId, block: BasicBlock) -> String {
  69     format!("bb{}__{}", block.index(), graphviz_safe_def_name(def_id))
  70 }