1 /* Template classes for directed graphs.
2    Copyright (C) 2019-2020 Free Software Foundation, Inc.
3    Contributed by David Malcolm <dmalcolm@redhat.com>.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11 
12 GCC is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 General Public License for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 #ifndef GCC_DIGRAPH_H
22 #define GCC_DIGRAPH_H
23 
24 #include "diagnostic.h"
25 #include "tree-diagnostic.h" /* for default_tree_printer.  */
26 #include "graphviz.h"
27 
28 /* Templates for a family of classes: digraph, node, edge, and cluster.
29    This assumes a traits type with the following typedefs:
30    node_t: the node class
31    edge_t: the edge class
32    dump_args_t: additional args for dot-dumps
33    cluster_t: the cluster class (for use when generating .dot files).
34 
35    Using a template allows for typesafe nodes and edges: a node's
36    predecessor and successor edges can be of a node-specific edge
37    subclass, without needing casting.  */
38 
39 /* Abstract base class for a node in a directed graph.  */
40 
41 template <typename GraphTraits>
42 class dnode
43 {
44  public:
45   typedef typename GraphTraits::edge_t edge_t;
46   typedef typename GraphTraits::dump_args_t dump_args_t;
47 
~dnode()48   virtual ~dnode () {}
49   virtual void dump_dot (graphviz_out *gv, const dump_args_t &args) const = 0;
50 
51   auto_vec<edge_t *> m_preds;
52   auto_vec<edge_t *> m_succs;
53 };
54 
55 /* Abstract base class for an edge in a directed graph.  */
56 
57 template <typename GraphTraits>
58 class dedge
59 {
60  public:
61   typedef typename GraphTraits::node_t node_t;
62   typedef typename GraphTraits::dump_args_t dump_args_t;
63 
dedge(node_t * src,node_t * dest)64   dedge (node_t *src, node_t *dest)
65   : m_src (src), m_dest (dest) {}
66 
~dedge()67   virtual ~dedge () {}
68 
69   virtual void dump_dot (graphviz_out *gv, const dump_args_t &args) const = 0;
70 
71   node_t *const m_src;
72   node_t *const m_dest;
73 };
74 
75 /* Abstract base class for a directed graph.
76    This class maintains the vectors of nodes and edges,
77    and owns the nodes and edges.  */
78 
79 template <typename GraphTraits>
80 class digraph
81 {
82  public:
83   typedef typename GraphTraits::node_t node_t;
84   typedef typename GraphTraits::edge_t edge_t;
85   typedef typename GraphTraits::dump_args_t dump_args_t;
86   typedef typename GraphTraits::cluster_t cluster_t;
87 
digraph()88   digraph () {}
~digraph()89   virtual ~digraph () {}
90 
91   void dump_dot_to_pp (pretty_printer *pp,
92 		       cluster_t *root_cluster,
93 		       const dump_args_t &args) const;
94   void dump_dot_to_file (FILE *fp,
95 			 cluster_t *root_cluster,
96 			 const dump_args_t &args) const;
97   void dump_dot (const char *path,
98 		 cluster_t *root_cluster,
99 		 const dump_args_t &args) const;
100 
101   void add_node (node_t *node);
102   void add_edge (edge_t *edge);
103 
104   auto_delete_vec<node_t> m_nodes;
105   auto_delete_vec<edge_t> m_edges;
106 };
107 
108 /* Abstract base class for splitting dnodes into hierarchical clusters
109    in the generated .dot file.
110 
111    See "Subgraphs and Clusters" within
112      https://www.graphviz.org/doc/info/lang.html
113    and e.g.
114      https://graphviz.gitlab.io/_pages/Gallery/directed/cluster.html
115 
116    If a root_cluster is passed to dump_dot*, then all nodes will be
117    added to it at the start of dumping, via calls to add_node.
118 
119    The root cluster can organize the nodes into a hierarchy of
120    child clusters.
121 
122    After all nodes are added to the root cluster, dump_dot will then
123    be called on it (and not on the nodes themselves).  */
124 
125 template <typename GraphTraits>
126 class cluster
127 {
128  public:
129   typedef typename GraphTraits::node_t node_t;
130   typedef typename GraphTraits::dump_args_t dump_args_t;
131 
~cluster()132   virtual ~cluster () {}
133 
134   virtual void add_node (node_t *node) = 0;
135 
136   /* Recursively dump the cluster, all nodes, and child clusters.  */
137   virtual void dump_dot (graphviz_out *gv, const dump_args_t &) const = 0;
138 };
139 
140 /* Write .dot information for this graph to PP, passing ARGS to the nodes
141    and edges.
142    If ROOT_CLUSTER is non-NULL, use it to organize the nodes into clusters.  */
143 
144 template <typename GraphTraits>
145 inline void
dump_dot_to_pp(pretty_printer * pp,cluster_t * root_cluster,const dump_args_t & args)146 digraph<GraphTraits>::dump_dot_to_pp (pretty_printer *pp,
147 				      cluster_t *root_cluster,
148 				      const dump_args_t &args) const
149 {
150   graphviz_out gv (pp);
151 
152   pp_string (pp, "digraph \"");
153   pp_string (pp, "base");
154   pp_string (pp, "\" {\n");
155 
156   gv.indent ();
157 
158   pp_string (pp, "overlap=false;\n");
159   pp_string (pp, "compound=true;\n");
160 
161   /* If using clustering, emit all nodes via clusters.  */
162   if (root_cluster)
163     {
164       int i;
165       node_t *n;
166       FOR_EACH_VEC_ELT (m_nodes, i, n)
167 	root_cluster->add_node (n);
168       root_cluster->dump_dot (&gv, args);
169     }
170   else
171     {
172       /* Otherwise, display all nodes at top level.  */
173       int i;
174       node_t *n;
175       FOR_EACH_VEC_ELT (m_nodes, i, n)
176 	n->dump_dot (&gv, args);
177     }
178 
179   /* Edges.  */
180   int i;
181   edge_t *e;
182   FOR_EACH_VEC_ELT (m_edges, i, e)
183     e->dump_dot (&gv, args);
184 
185   /* Terminate "digraph" */
186   gv.outdent ();
187   pp_string (pp, "}");
188   pp_newline (pp);
189 }
190 
191 /* Write .dot information for this graph to FP, passing ARGS to the nodes
192    and edges.
193    If ROOT_CLUSTER is non-NULL, use it to organize the nodes into clusters.  */
194 
195 template <typename GraphTraits>
196 inline void
dump_dot_to_file(FILE * fp,cluster_t * root_cluster,const dump_args_t & args)197 digraph<GraphTraits>::dump_dot_to_file (FILE *fp,
198 					cluster_t *root_cluster,
199 					const dump_args_t &args) const
200 {
201   pretty_printer pp;
202   // TODO:
203   pp_format_decoder (&pp) = default_tree_printer;
204   pp.buffer->stream = fp;
205   dump_dot_to_pp (&pp, root_cluster, args);
206   pp_flush (&pp);
207 }
208 
209 /* Write .dot information for this graph to a file at PATH, passing ARGS
210    to the nodes and edges.
211    If ROOT_CLUSTER is non-NULL, use it to organize the nodes into clusters.  */
212 
213 template <typename GraphTraits>
214 inline void
dump_dot(const char * path,cluster_t * root_cluster,const dump_args_t & args)215 digraph<GraphTraits>::dump_dot (const char *path,
216 				cluster_t *root_cluster,
217 				const dump_args_t &args) const
218 {
219   FILE *fp = fopen (path, "w");
220   dump_dot_to_file (fp, root_cluster, args);
221   fclose (fp);
222 }
223 
224 /* Add NODE to this DIGRAPH, taking ownership.  */
225 
226 template <typename GraphTraits>
227 inline void
add_node(node_t * node)228 digraph<GraphTraits>::add_node (node_t *node)
229 {
230   m_nodes.safe_push (node);
231 }
232 
233 /* Add EDGE to this digraph, and to the preds/succs of its endpoints.
234    Take ownership of EDGE.  */
235 
236 template <typename GraphTraits>
237 inline void
add_edge(edge_t * edge)238 digraph<GraphTraits>::add_edge (edge_t *edge)
239 {
240   m_edges.safe_push (edge);
241   edge->m_dest->m_preds.safe_push (edge);
242   edge->m_src->m_succs.safe_push (edge);
243 
244 }
245 
246 #endif /* GCC_DIGRAPH_H */
247