1//===- llvm/Support/GraphWriter.h - Write graph to a .dot file --*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines a simple interface that can be used to print out generic
10// LLVM graphs to ".dot" files.  "dot" is a tool that is part of the AT&T
11// graphviz package (http://www.research.att.com/sw/tools/graphviz/) which can
12// be used to turn the files output by this interface into a variety of
13// different graphics formats.
14//
15// Graphs do not need to implement any interface past what is already required
16// by the GraphTraits template, but they can choose to implement specializations
17// of the DOTGraphTraits template if they want to customize the graphs output in
18// any way.
19//
20//===----------------------------------------------------------------------===//
21
22#ifndef LLVM_SUPPORT_GRAPHWRITER_H
23#define LLVM_SUPPORT_GRAPHWRITER_H
24
25#include "llvm/ADT/GraphTraits.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/ADT/Twine.h"
28#include "llvm/Support/DOTGraphTraits.h"
29#include "llvm/Support/FileSystem.h"
30#include "llvm/Support/raw_ostream.h"
31#include <algorithm>
32#include <cstddef>
33#include <iterator>
34#include <string>
35#include <type_traits>
36#include <vector>
37
38namespace llvm {
39
40namespace DOT {  // Private functions...
41
42std::string EscapeString(const std::string &Label);
43
44/// Get a color string for this node number. Simply round-robin selects
45/// from a reasonable number of colors.
46StringRef getColorString(unsigned NodeNumber);
47
48} // end namespace DOT
49
50namespace GraphProgram {
51
52enum Name {
53  DOT,
54  FDP,
55  NEATO,
56  TWOPI,
57  CIRCO
58};
59
60} // end namespace GraphProgram
61
62bool DisplayGraph(StringRef Filename, bool wait = true,
63                  GraphProgram::Name program = GraphProgram::DOT);
64
65template<typename GraphType>
66class GraphWriter {
67  raw_ostream &O;
68  const GraphType &G;
69
70  using DOTTraits = DOTGraphTraits<GraphType>;
71  using GTraits = GraphTraits<GraphType>;
72  using NodeRef = typename GTraits::NodeRef;
73  using node_iterator = typename GTraits::nodes_iterator;
74  using child_iterator = typename GTraits::ChildIteratorType;
75  DOTTraits DTraits;
76
77  static_assert(std::is_pointer<NodeRef>::value,
78                "FIXME: Currently GraphWriter requires the NodeRef type to be "
79                "a pointer.\nThe pointer usage should be moved to "
80                "DOTGraphTraits, and removed from GraphWriter itself.");
81
82  // Writes the edge labels of the node to O and returns true if there are any
83  // edge labels not equal to the empty string "".
84  bool getEdgeSourceLabels(raw_ostream &O, NodeRef Node) {
85    child_iterator EI = GTraits::child_begin(Node);
86    child_iterator EE = GTraits::child_end(Node);
87    bool hasEdgeSourceLabels = false;
88
89    for (unsigned i = 0; EI != EE && i != 64; ++EI, ++i) {
90      std::string label = DTraits.getEdgeSourceLabel(Node, EI);
91
92      if (label.empty())
93        continue;
94
95      hasEdgeSourceLabels = true;
96
97      if (i)
98        O << "|";
99
100      O << "<s" << i << ">" << DOT::EscapeString(label);
101    }
102
103    if (EI != EE && hasEdgeSourceLabels)
104      O << "|<s64>truncated...";
105
106    return hasEdgeSourceLabels;
107  }
108
109public:
110  GraphWriter(raw_ostream &o, const GraphType &g, bool SN) : O(o), G(g) {
111    DTraits = DOTTraits(SN);
112  }
113
114  void writeGraph(const std::string &Title = "") {
115    // Output the header for the graph...
116    writeHeader(Title);
117
118    // Emit all of the nodes in the graph...
119    writeNodes();
120
121    // Output any customizations on the graph
122    DOTGraphTraits<GraphType>::addCustomGraphFeatures(G, *this);
123
124    // Output the end of the graph
125    writeFooter();
126  }
127
128  void writeHeader(const std::string &Title) {
129    std::string GraphName = DTraits.getGraphName(G);
130
131    if (!Title.empty())
132      O << "digraph \"" << DOT::EscapeString(Title) << "\" {\n";
133    else if (!GraphName.empty())
134      O << "digraph \"" << DOT::EscapeString(GraphName) << "\" {\n";
135    else
136      O << "digraph unnamed {\n";
137
138    if (DTraits.renderGraphFromBottomUp())
139      O << "\trankdir=\"BT\";\n";
140
141    if (!Title.empty())
142      O << "\tlabel=\"" << DOT::EscapeString(Title) << "\";\n";
143    else if (!GraphName.empty())
144      O << "\tlabel=\"" << DOT::EscapeString(GraphName) << "\";\n";
145    O << DTraits.getGraphProperties(G);
146    O << "\n";
147  }
148
149  void writeFooter() {
150    // Finish off the graph
151    O << "}\n";
152  }
153
154  void writeNodes() {
155    // Loop over the graph, printing it out...
156    for (const auto Node : nodes<GraphType>(G))
157      if (!isNodeHidden(Node))
158        writeNode(Node);
159  }
160
161  bool isNodeHidden(NodeRef Node) {
162    return DTraits.isNodeHidden(Node);
163  }
164
165  void writeNode(NodeRef Node) {
166    std::string NodeAttributes = DTraits.getNodeAttributes(Node, G);
167
168    O << "\tNode" << static_cast<const void*>(Node) << " [shape=record,";
169    if (!NodeAttributes.empty()) O << NodeAttributes << ",";
170    O << "label=\"{";
171
172    if (!DTraits.renderGraphFromBottomUp()) {
173      O << DOT::EscapeString(DTraits.getNodeLabel(Node, G));
174
175      // If we should include the address of the node in the label, do so now.
176      std::string Id = DTraits.getNodeIdentifierLabel(Node, G);
177      if (!Id.empty())
178        O << "|" << DOT::EscapeString(Id);
179
180      std::string NodeDesc = DTraits.getNodeDescription(Node, G);
181      if (!NodeDesc.empty())
182        O << "|" << DOT::EscapeString(NodeDesc);
183    }
184
185    std::string edgeSourceLabels;
186    raw_string_ostream EdgeSourceLabels(edgeSourceLabels);
187    bool hasEdgeSourceLabels = getEdgeSourceLabels(EdgeSourceLabels, Node);
188
189    if (hasEdgeSourceLabels) {
190      if (!DTraits.renderGraphFromBottomUp()) O << "|";
191
192      O << "{" << EdgeSourceLabels.str() << "}";
193
194      if (DTraits.renderGraphFromBottomUp()) O << "|";
195    }
196
197    if (DTraits.renderGraphFromBottomUp()) {
198      O << DOT::EscapeString(DTraits.getNodeLabel(Node, G));
199
200      // If we should include the address of the node in the label, do so now.
201      std::string Id = DTraits.getNodeIdentifierLabel(Node, G);
202      if (!Id.empty())
203        O << "|" << DOT::EscapeString(Id);
204
205      std::string NodeDesc = DTraits.getNodeDescription(Node, G);
206      if (!NodeDesc.empty())
207        O << "|" << DOT::EscapeString(NodeDesc);
208    }
209
210    if (DTraits.hasEdgeDestLabels()) {
211      O << "|{";
212
213      unsigned i = 0, e = DTraits.numEdgeDestLabels(Node);
214      for (; i != e && i != 64; ++i) {
215        if (i) O << "|";
216        O << "<d" << i << ">"
217          << DOT::EscapeString(DTraits.getEdgeDestLabel(Node, i));
218      }
219
220      if (i != e)
221        O << "|<d64>truncated...";
222      O << "}";
223    }
224
225    O << "}\"];\n";   // Finish printing the "node" line
226
227    // Output all of the edges now
228    child_iterator EI = GTraits::child_begin(Node);
229    child_iterator EE = GTraits::child_end(Node);
230    for (unsigned i = 0; EI != EE && i != 64; ++EI, ++i)
231      if (!DTraits.isNodeHidden(*EI))
232        writeEdge(Node, i, EI);
233    for (; EI != EE; ++EI)
234      if (!DTraits.isNodeHidden(*EI))
235        writeEdge(Node, 64, EI);
236  }
237
238  void writeEdge(NodeRef Node, unsigned edgeidx, child_iterator EI) {
239    if (NodeRef TargetNode = *EI) {
240      int DestPort = -1;
241      if (DTraits.edgeTargetsEdgeSource(Node, EI)) {
242        child_iterator TargetIt = DTraits.getEdgeTarget(Node, EI);
243
244        // Figure out which edge this targets...
245        unsigned Offset =
246          (unsigned)std::distance(GTraits::child_begin(TargetNode), TargetIt);
247        DestPort = static_cast<int>(Offset);
248      }
249
250      if (DTraits.getEdgeSourceLabel(Node, EI).empty())
251        edgeidx = -1;
252
253      emitEdge(static_cast<const void*>(Node), edgeidx,
254               static_cast<const void*>(TargetNode), DestPort,
255               DTraits.getEdgeAttributes(Node, EI, G));
256    }
257  }
258
259  /// emitSimpleNode - Outputs a simple (non-record) node
260  void emitSimpleNode(const void *ID, const std::string &Attr,
261                   const std::string &Label, unsigned NumEdgeSources = 0,
262                   const std::vector<std::string> *EdgeSourceLabels = nullptr) {
263    O << "\tNode" << ID << "[ ";
264    if (!Attr.empty())
265      O << Attr << ",";
266    O << " label =\"";
267    if (NumEdgeSources) O << "{";
268    O << DOT::EscapeString(Label);
269    if (NumEdgeSources) {
270      O << "|{";
271
272      for (unsigned i = 0; i != NumEdgeSources; ++i) {
273        if (i) O << "|";
274        O << "<s" << i << ">";
275        if (EdgeSourceLabels) O << DOT::EscapeString((*EdgeSourceLabels)[i]);
276      }
277      O << "}}";
278    }
279    O << "\"];\n";
280  }
281
282  /// emitEdge - Output an edge from a simple node into the graph...
283  void emitEdge(const void *SrcNodeID, int SrcNodePort,
284                const void *DestNodeID, int DestNodePort,
285                const std::string &Attrs) {
286    if (SrcNodePort  > 64) return;             // Eminating from truncated part?
287    if (DestNodePort > 64) DestNodePort = 64;  // Targeting the truncated part?
288
289    O << "\tNode" << SrcNodeID;
290    if (SrcNodePort >= 0)
291      O << ":s" << SrcNodePort;
292    O << " -> Node" << DestNodeID;
293    if (DestNodePort >= 0 && DTraits.hasEdgeDestLabels())
294      O << ":d" << DestNodePort;
295
296    if (!Attrs.empty())
297      O << "[" << Attrs << "]";
298    O << ";\n";
299  }
300
301  /// getOStream - Get the raw output stream into the graph file. Useful to
302  /// write fancy things using addCustomGraphFeatures().
303  raw_ostream &getOStream() {
304    return O;
305  }
306};
307
308template<typename GraphType>
309raw_ostream &WriteGraph(raw_ostream &O, const GraphType &G,
310                        bool ShortNames = false,
311                        const Twine &Title = "") {
312  // Start the graph emission process...
313  GraphWriter<GraphType> W(O, G, ShortNames);
314
315  // Emit the graph.
316  W.writeGraph(Title.str());
317
318  return O;
319}
320
321std::string createGraphFilename(const Twine &Name, int &FD);
322
323/// Writes graph into a provided {@code Filename}.
324/// If {@code Filename} is empty, generates a random one.
325/// \return The resulting filename, or an empty string if writing
326/// failed.
327template <typename GraphType>
328std::string WriteGraph(const GraphType &G, const Twine &Name,
329                       bool ShortNames = false,
330                       const Twine &Title = "",
331                       std::string Filename = "") {
332  int FD;
333  // Windows can't always handle long paths, so limit the length of the name.
334  std::string N = Name.str();
335  N = N.substr(0, std::min<std::size_t>(N.size(), 140));
336  if (Filename.empty()) {
337    Filename = createGraphFilename(N, FD);
338  } else {
339    std::error_code EC = sys::fs::openFileForWrite(Filename, FD);
340
341    // Writing over an existing file is not considered an error.
342    if (EC == std::errc::file_exists) {
343      errs() << "file exists, overwriting" << "\n";
344    } else if (EC) {
345      errs() << "error writing into file" << "\n";
346      return "";
347    }
348  }
349  raw_fd_ostream O(FD, /*shouldClose=*/ true);
350
351  if (FD == -1) {
352    errs() << "error opening file '" << Filename << "' for writing!\n";
353    return "";
354  }
355
356  llvm::WriteGraph(O, G, ShortNames, Title);
357  errs() << " done. \n";
358
359  return Filename;
360}
361
362/// ViewGraph - Emit a dot graph, run 'dot', run gv on the postscript file,
363/// then cleanup.  For use from the debugger.
364///
365template<typename GraphType>
366void ViewGraph(const GraphType &G, const Twine &Name,
367               bool ShortNames = false, const Twine &Title = "",
368               GraphProgram::Name Program = GraphProgram::DOT) {
369  std::string Filename = llvm::WriteGraph(G, Name, ShortNames, Title);
370
371  if (Filename.empty())
372    return;
373
374  DisplayGraph(Filename, false, Program);
375}
376
377} // end namespace llvm
378
379#endif // LLVM_SUPPORT_GRAPHWRITER_H
380