lib/CompilerDriver/CompilationGraph.cpp

   1 //===--- CompilationGraph.cpp - The LLVM Compiler Driver --------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open
   6 // Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 //  Compilation graph - implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CompilerDriver/CompilationGraph.h"
  15 #include "llvm/CompilerDriver/Error.h"
  16
  17 #include "llvm/ADT/STLExtras.h"
  18 #include "llvm/Support/CommandLine.h"
  19 #include "llvm/Support/DOTGraphTraits.h"
  20 #include "llvm/Support/GraphWriter.h"
  21
  22 #include <algorithm>
  23 #include <cstring>
  24 #include <iostream>
  25 #include <iterator>
  26 #include <limits>
  27 #include <queue>
  28 #include <stdexcept>
  29
  30 using namespace llvm;
  31 using namespace llvmc;
  32
  33 extern cl::list<std::string> InputFilenames;
  34 extern cl::list<std::string> Languages;
  35
  36 namespace llvmc {
  37
  38   const std::string& LanguageMap::GetLanguage(const sys::Path& File) const {
  39     LanguageMap::const_iterator Lang = this->find(File.getSuffix());
  40     if (Lang == this->end())
  41       throw std::runtime_error("Unknown suffix: " + File.getSuffix());
  42     return Lang->second;
  43   }
  44 }
  45
  46 namespace {
  47
  48   /// ChooseEdge - Return the edge with the maximum weight.
  49   template <class C>
  50   const Edge* ChooseEdge(const C& EdgesContainer,
  51                          const InputLanguagesSet& InLangs,
  52                          const std::string& NodeName = "root") {
  53     const Edge* MaxEdge = 0;
  54     unsigned MaxWeight = 0;
  55     bool SingleMax = true;
  56
  57     for (typename C::const_iterator B = EdgesContainer.begin(),
  58            E = EdgesContainer.end(); B != E; ++B) {
  59       const Edge* e = B->getPtr();
  60       unsigned EW = e->Weight(InLangs);
  61       if (EW > MaxWeight) {
  62         MaxEdge = e;
  63         MaxWeight = EW;
  64         SingleMax = true;
  65       } else if (EW == MaxWeight) {
  66         SingleMax = false;
  67       }
  68     }
  69
  70     if (!SingleMax)
  71       throw std::runtime_error("Node " + NodeName +
  72                                ": multiple maximal outward edges found!"
  73                                " Most probably a specification error.");
  74     if (!MaxEdge)
  75       throw std::runtime_error("Node " + NodeName +
  76                                ": no maximal outward edge found!"
  77                                " Most probably a specification error.");
  78     return MaxEdge;
  79   }
  80
  81 }
  82
  83 void Node::AddEdge(Edge* Edg) {
  84   // If there already was an edge between two nodes, modify it instead
  85   // of adding a new edge.
  86   const std::string& ToolName = Edg->ToolName();
  87   for (container_type::iterator B = OutEdges.begin(), E = OutEdges.end();
  88        B != E; ++B) {
  89     if ((*B)->ToolName() == ToolName) {
  90       llvm::IntrusiveRefCntPtr<Edge>(Edg).swap(*B);
  91       return;
  92     }
  93   }
  94   OutEdges.push_back(llvm::IntrusiveRefCntPtr<Edge>(Edg));
  95 }
  96
  97 CompilationGraph::CompilationGraph() {
  98   NodesMap["root"] = Node(this);
  99 }
 100
 101 Node& CompilationGraph::getNode(const std::string& ToolName) {
 102   nodes_map_type::iterator I = NodesMap.find(ToolName);
 103   if (I == NodesMap.end())
 104     throw std::runtime_error("Node " + ToolName + " is not in the graph");
 105   return I->second;
 106 }
 107
 108 const Node& CompilationGraph::getNode(const std::string& ToolName) const {
 109   nodes_map_type::const_iterator I = NodesMap.find(ToolName);
 110   if (I == NodesMap.end())
 111     throw std::runtime_error("Node " + ToolName + " is not in the graph!");
 112   return I->second;
 113 }
 114
 115 // Find the tools list corresponding to the given language name.
 116 const CompilationGraph::tools_vector_type&
 117 CompilationGraph::getToolsVector(const std::string& LangName) const
 118 {
 119   tools_map_type::const_iterator I = ToolsMap.find(LangName);
 120   if (I == ToolsMap.end())
 121     throw std::runtime_error("No tool corresponding to the language "
 122                              + LangName + " found");
 123   return I->second;
 124 }
 125
 126 void CompilationGraph::insertNode(Tool* V) {
 127   if (NodesMap.count(V->Name()) == 0)
 128     NodesMap[V->Name()] = Node(this, V);
 129 }
 130
 131 void CompilationGraph::insertEdge(const std::string& A, Edge* Edg) {
 132   Node& B = getNode(Edg->ToolName());
 133   if (A == "root") {
 134     const char** InLangs = B.ToolPtr->InputLanguages();
 135     for (;*InLangs; ++InLangs)
 136       ToolsMap[*InLangs].push_back(IntrusiveRefCntPtr<Edge>(Edg));
 137     NodesMap["root"].AddEdge(Edg);
 138   }
 139   else {
 140     Node& N = getNode(A);
 141     N.AddEdge(Edg);
 142   }
 143   // Increase the inward edge counter.
 144   B.IncrInEdges();
 145 }
 146
 147 // Pass input file through the chain until we bump into a Join node or
 148 // a node that says that it is the last.
 149 void CompilationGraph::PassThroughGraph (const sys::Path& InFile,
 150                                          const Node* StartNode,
 151                                          const InputLanguagesSet& InLangs,
 152                                          const sys::Path& TempDir,
 153                                          const LanguageMap& LangMap) const {
 154   sys::Path In = InFile;
 155   const Node* CurNode = StartNode;
 156
 157   while(true) {
 158     Tool* CurTool = CurNode->ToolPtr.getPtr();
 159
 160     if (CurTool->IsJoin()) {
 161       JoinTool& JT = dynamic_cast<JoinTool&>(*CurTool);
 162       JT.AddToJoinList(In);
 163       break;
 164     }
 165
 166     Action CurAction = CurTool->GenerateAction(In, CurNode->HasChildren(),
 167                                                TempDir, InLangs, LangMap);
 168
 169     if (int ret = CurAction.Execute())
 170       throw error_code(ret);
 171
 172     if (CurAction.StopCompilation())
 173       return;
 174
 175     CurNode = &getNode(ChooseEdge(CurNode->OutEdges,
 176                                   InLangs,
 177                                   CurNode->Name())->ToolName());
 178     In = CurAction.OutFile();
 179   }
 180 }
 181
 182 // Find the head of the toolchain corresponding to the given file.
 183 // Also, insert an input language into InLangs.
 184 const Node* CompilationGraph::
 185 FindToolChain(const sys::Path& In, const std::string* ForceLanguage,
 186               InputLanguagesSet& InLangs, const LanguageMap& LangMap) const {
 187
 188   // Determine the input language.
 189   const std::string& InLanguage =
 190     ForceLanguage ? *ForceLanguage : LangMap.GetLanguage(In);
 191
 192   // Add the current input language to the input language set.
 193   InLangs.insert(InLanguage);
 194
 195   // Find the toolchain for the input language.
 196   const tools_vector_type& TV = getToolsVector(InLanguage);
 197   if (TV.empty())
 198     throw std::runtime_error("No toolchain corresponding to language "
 199                              + InLanguage + " found");
 200   return &getNode(ChooseEdge(TV, InLangs)->ToolName());
 201 }
 202
 203 // Helper function used by Build().
 204 // Traverses initial portions of the toolchains (up to the first Join node).
 205 // This function is also responsible for handling the -x option.
 206 void CompilationGraph::BuildInitial (InputLanguagesSet& InLangs,
 207                                      const sys::Path& TempDir,
 208                                      const LanguageMap& LangMap) {
 209   // This is related to -x option handling.
 210   cl::list<std::string>::const_iterator xIter = Languages.begin(),
 211     xBegin = xIter, xEnd = Languages.end();
 212   bool xEmpty = true;
 213   const std::string* xLanguage = 0;
 214   unsigned xPos = 0, xPosNext = 0, filePos = 0;
 215
 216   if (xIter != xEnd) {
 217     xEmpty = false;
 218     xPos = Languages.getPosition(xIter - xBegin);
 219     cl::list<std::string>::const_iterator xNext = llvm::next(xIter);
 220     xPosNext = (xNext == xEnd) ? std::numeric_limits<unsigned>::max()
 221       : Languages.getPosition(xNext - xBegin);
 222     xLanguage = (*xIter == "none") ? 0 : &(*xIter);
 223   }
 224
 225   // For each input file:
 226   for (cl::list<std::string>::const_iterator B = InputFilenames.begin(),
 227          CB = B, E = InputFilenames.end(); B != E; ++B) {
 228     sys::Path In = sys::Path(*B);
 229
 230     // Code for handling the -x option.
 231     // Output: std::string* xLanguage (can be NULL).
 232     if (!xEmpty) {
 233       filePos = InputFilenames.getPosition(B - CB);
 234
 235       if (xPos < filePos) {
 236         if (filePos < xPosNext) {
 237           xLanguage = (*xIter == "none") ? 0 : &(*xIter);
 238         }
 239         else { // filePos >= xPosNext
 240           // Skip xIters while filePos > xPosNext
 241           while (filePos > xPosNext) {
 242             ++xIter;
 243             xPos = xPosNext;
 244
 245             cl::list<std::string>::const_iterator xNext = llvm::next(xIter);
 246             if (xNext == xEnd)
 247               xPosNext = std::numeric_limits<unsigned>::max();
 248             else
 249               xPosNext = Languages.getPosition(xNext - xBegin);
 250             xLanguage = (*xIter == "none") ? 0 : &(*xIter);
 251           }
 252         }
 253       }
 254     }
 255
 256     // Find the toolchain corresponding to this file.
 257     const Node* N = FindToolChain(In, xLanguage, InLangs, LangMap);
 258     // Pass file through the chain starting at head.
 259     PassThroughGraph(In, N, InLangs, TempDir, LangMap);
 260   }
 261 }
 262
 263 // Sort the nodes in topological order.
 264 void CompilationGraph::TopologicalSort(std::vector<const Node*>& Out) {
 265   std::queue<const Node*> Q;
 266   Q.push(&getNode("root"));
 267
 268   while (!Q.empty()) {
 269     const Node* A = Q.front();
 270     Q.pop();
 271     Out.push_back(A);
 272     for (Node::const_iterator EB = A->EdgesBegin(), EE = A->EdgesEnd();
 273          EB != EE; ++EB) {
 274       Node* B = &getNode((*EB)->ToolName());
 275       B->DecrInEdges();
 276       if (B->HasNoInEdges())
 277         Q.push(B);
 278     }
 279   }
 280 }
 281
 282 namespace {
 283   bool NotJoinNode(const Node* N) {
 284     return N->ToolPtr ? !N->ToolPtr->IsJoin() : true;
 285   }
 286 }
 287
 288 // Call TopologicalSort and filter the resulting list to include
 289 // only Join nodes.
 290 void CompilationGraph::
 291 TopologicalSortFilterJoinNodes(std::vector<const Node*>& Out) {
 292   std::vector<const Node*> TopSorted;
 293   TopologicalSort(TopSorted);
 294   std::remove_copy_if(TopSorted.begin(), TopSorted.end(),
 295                       std::back_inserter(Out), NotJoinNode);
 296 }
 297
 298 int CompilationGraph::Build (const sys::Path& TempDir,
 299                              const LanguageMap& LangMap) {
 300
 301   InputLanguagesSet InLangs;
 302
 303   // Traverse initial parts of the toolchains and fill in InLangs.
 304   BuildInitial(InLangs, TempDir, LangMap);
 305
 306   std::vector<const Node*> JTV;
 307   TopologicalSortFilterJoinNodes(JTV);
 308
 309   // For all join nodes in topological order:
 310   for (std::vector<const Node*>::iterator B = JTV.begin(), E = JTV.end();
 311        B != E; ++B) {
 312
 313     const Node* CurNode = *B;
 314     JoinTool* JT = &dynamic_cast<JoinTool&>(*CurNode->ToolPtr.getPtr());
 315
 316     // Are there any files in the join list?
 317     if (JT->JoinListEmpty())
 318       continue;
 319
 320     Action CurAction = JT->GenerateAction(CurNode->HasChildren(),
 321                                           TempDir, InLangs, LangMap);
 322
 323     if (int ret = CurAction.Execute())
 324       throw error_code(ret);
 325
 326     if (CurAction.StopCompilation())
 327       return 0;
 328
 329     const Node* NextNode = &getNode(ChooseEdge(CurNode->OutEdges, InLangs,
 330                                                CurNode->Name())->ToolName());
 331     PassThroughGraph(sys::Path(CurAction.OutFile()), NextNode,
 332                      InLangs, TempDir, LangMap);
 333   }
 334
 335   return 0;
 336 }
 337
 338 int CompilationGraph::CheckLanguageNames() const {
 339   int ret = 0;
 340   // Check that names for output and input languages on all edges do match.
 341   for (const_nodes_iterator B = this->NodesMap.begin(),
 342          E = this->NodesMap.end(); B != E; ++B) {
 343
 344     const Node & N1 = B->second;
 345     if (N1.ToolPtr) {
 346       for (Node::const_iterator EB = N1.EdgesBegin(), EE = N1.EdgesEnd();
 347            EB != EE; ++EB) {
 348         const Node& N2 = this->getNode((*EB)->ToolName());
 349
 350         if (!N2.ToolPtr) {
 351           ++ret;
 352           std::cerr << "Error: there is an edge from '" << N1.ToolPtr->Name()
 353                     << "' back to the root!\n\n";
 354           continue;
 355         }
 356
 357         const char* OutLang = N1.ToolPtr->OutputLanguage();
 358         const char** InLangs = N2.ToolPtr->InputLanguages();
 359         bool eq = false;
 360         for (;*InLangs; ++InLangs) {
 361           if (std::strcmp(OutLang, *InLangs) == 0) {
 362             eq = true;
 363             break;
 364           }
 365         }
 366
 367         if (!eq) {
 368           ++ret;
 369           std::cerr << "Error: Output->input language mismatch in the edge '" <<
 370             N1.ToolPtr->Name() << "' -> '" << N2.ToolPtr->Name() << "'!\n";
 371
 372           std::cerr << "Expected one of { ";
 373
 374           InLangs = N2.ToolPtr->InputLanguages();
 375           for (;*InLangs; ++InLangs) {
 376             std::cerr << '\'' << *InLangs << (*(InLangs+1) ? "', " : "'");
 377           }
 378
 379           std::cerr << " }, but got '" << OutLang << "'!\n\n";
 380         }
 381
 382       }
 383     }
 384   }
 385
 386   return ret;
 387 }
 388
 389 int CompilationGraph::CheckMultipleDefaultEdges() const {
 390   int ret = 0;
 391   InputLanguagesSet Dummy;
 392
 393   // For all nodes, just iterate over the outgoing edges and check if there is
 394   // more than one edge with maximum weight.
 395   for (const_nodes_iterator B = this->NodesMap.begin(),
 396          E = this->NodesMap.end(); B != E; ++B) {
 397     const Node& N = B->second;
 398     unsigned MaxWeight = 0;
 399
 400     // Ignore the root node.
 401     if (!N.ToolPtr)
 402       continue;
 403
 404     for (Node::const_iterator EB = N.EdgesBegin(), EE = N.EdgesEnd();
 405          EB != EE; ++EB) {
 406       unsigned EdgeWeight = (*EB)->Weight(Dummy);
 407       if (EdgeWeight > MaxWeight) {
 408         MaxWeight = EdgeWeight;
 409       }
 410       else if (EdgeWeight == MaxWeight) {
 411         ++ret;
 412         std::cerr
 413           << "Error: there are multiple maximal edges stemming from the '"
 414           << N.ToolPtr->Name() << "' node!\n\n";
 415         break;
 416       }
 417     }
 418   }
 419
 420   return ret;
 421 }
 422
 423 int CompilationGraph::CheckCycles() {
 424   unsigned deleted = 0;
 425   std::queue<Node*> Q;
 426   Q.push(&getNode("root"));
 427
 428   // Try to delete all nodes that have no ingoing edges, starting from the
 429   // root. If there are any nodes left after this operation, then we have a
 430   // cycle. This relies on '--check-graph' not performing the topological sort.
 431   while (!Q.empty()) {
 432     Node* A = Q.front();
 433     Q.pop();
 434     ++deleted;
 435
 436     for (Node::iterator EB = A->EdgesBegin(), EE = A->EdgesEnd();
 437          EB != EE; ++EB) {
 438       Node* B = &getNode((*EB)->ToolName());
 439       B->DecrInEdges();
 440       if (B->HasNoInEdges())
 441         Q.push(B);
 442     }
 443   }
 444
 445   if (deleted != NodesMap.size()) {
 446     std::cerr << "Error: there are cycles in the compilation graph!\n"
 447               << "Try inspecting the diagram produced by "
 448       "'llvmc --view-graph'.\n\n";
 449     return 1;
 450   }
 451
 452   return 0;
 453 }
 454
 455 int CompilationGraph::Check () {
 456   // We try to catch as many errors as we can in one go.
 457   int ret = 0;
 458
 459   // Check that output/input language names match.
 460   ret += this->CheckLanguageNames();
 461
 462   // Check for multiple default edges.
 463   ret += this->CheckMultipleDefaultEdges();
 464
 465   // Check for cycles.
 466   ret += this->CheckCycles();
 467
 468   return ret;
 469 }
 470
 471 // Code related to graph visualization.
 472
 473 namespace llvm {
 474   template <>
 475   struct DOTGraphTraits<llvmc::CompilationGraph*>
 476     : public DefaultDOTGraphTraits
 477   {
 478
 479     template<typename GraphType>
 480     static std::string getNodeLabel(const Node* N, const GraphType&)
 481     {
 482       if (N->ToolPtr)
 483         if (N->ToolPtr->IsJoin())
 484           return N->Name() + "\n (join" +
 485             (N->HasChildren() ? ")"
 486              : std::string(": ") + N->ToolPtr->OutputLanguage() + ')');
 487         else
 488           return N->Name();
 489       else
 490         return "root";
 491     }
 492
 493     template<typename EdgeIter>
 494     static std::string getEdgeSourceLabel(const Node* N, EdgeIter I) {
 495       if (N->ToolPtr) {
 496         return N->ToolPtr->OutputLanguage();
 497       }
 498       else {
 499         const char** InLangs = I->ToolPtr->InputLanguages();
 500         std::string ret;
 501
 502         for (; *InLangs; ++InLangs) {
 503           if (*(InLangs + 1)) {
 504             ret += *InLangs;
 505             ret +=  ", ";
 506           }
 507           else {
 508             ret += *InLangs;
 509           }
 510         }
 511
 512         return ret;
 513       }
 514     }
 515   };
 516
 517 }
 518
 519 void CompilationGraph::writeGraph(const std::string& OutputFilename) {
 520   std::ofstream O(OutputFilename.c_str());
 521
 522   if (O.good()) {
 523     std::cerr << "Writing '"<< OutputFilename << "' file...";
 524     llvm::WriteGraph(O, this);
 525     std::cerr << "done.\n";
 526     O.close();
 527   }
 528   else {
 529     throw std::runtime_error("Error opening file '" + OutputFilename
 530                              + "' for writing!");
 531   }
 532 }
 533
 534 void CompilationGraph::viewGraph() {
 535   llvm::ViewGraph(this, "compilation-graph");
 536 }