include/llvm/Support/GraphWriter.h

   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
  38 namespace llvm {
  39
  40 namespace DOT {  // Private functions...
  41
  42 std::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.
  46 StringRef getColorString(unsigned NodeNumber);
  47
  48 } // end namespace DOT
  49
  50 namespace GraphProgram {
  51
  52 enum Name {
  53   DOT,
  54   FDP,
  55   NEATO,
  56   TWOPI,
  57   CIRCO
  58 };
  59
  60 } // end namespace GraphProgram
  61
  62 bool DisplayGraph(StringRef Filename, bool wait = true,
  63                   GraphProgram::Name program = GraphProgram::DOT);
  64
  65 template<typename GraphType>
  66 class 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
 109 public:
 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
 308 template<typename GraphType>
 309 raw_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
 321 std::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.
 327 template <typename GraphType>
 328 std::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 ///
 365 template<typename GraphType>
 366 void 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