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      1 //===--- Module.cpp - Describe a module -----------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file defines the Module class, which describes a module in the source
     11 // code.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #include "clang/Basic/Module.h"
     16 #include "clang/Basic/FileManager.h"
     17 #include "clang/Basic/LangOptions.h"
     18 #include "clang/Basic/TargetInfo.h"
     19 #include "llvm/ADT/ArrayRef.h"
     20 #include "llvm/ADT/SmallVector.h"
     21 #include "llvm/ADT/StringSwitch.h"
     22 #include "llvm/Support/ErrorHandling.h"
     23 #include "llvm/Support/raw_ostream.h"
     24 
     25 using namespace clang;
     26 
     27 Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
     28                const FileEntry *File, bool IsFramework, bool IsExplicit)
     29     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent), ModuleMap(File),
     30       Umbrella(), ASTFile(nullptr), IsMissingRequirement(false),
     31       IsAvailable(true), IsFromModuleFile(false), IsFramework(IsFramework),
     32       IsExplicit(IsExplicit), IsSystem(false), IsExternC(false),
     33       IsInferred(false), InferSubmodules(false), InferExplicitSubmodules(false),
     34       InferExportWildcard(false), ConfigMacrosExhaustive(false),
     35       NameVisibility(Hidden) {
     36   if (Parent) {
     37     if (!Parent->isAvailable())
     38       IsAvailable = false;
     39     if (Parent->IsSystem)
     40       IsSystem = true;
     41     if (Parent->IsExternC)
     42       IsExternC = true;
     43     IsMissingRequirement = Parent->IsMissingRequirement;
     44 
     45     Parent->SubModuleIndex[Name] = Parent->SubModules.size();
     46     Parent->SubModules.push_back(this);
     47   }
     48 }
     49 
     50 Module::~Module() {
     51   for (submodule_iterator I = submodule_begin(), IEnd = submodule_end();
     52        I != IEnd; ++I) {
     53     delete *I;
     54   }
     55 }
     56 
     57 /// \brief Determine whether a translation unit built using the current
     58 /// language options has the given feature.
     59 static bool hasFeature(StringRef Feature, const LangOptions &LangOpts,
     60                        const TargetInfo &Target) {
     61   return llvm::StringSwitch<bool>(Feature)
     62            .Case("altivec", LangOpts.AltiVec)
     63            .Case("blocks", LangOpts.Blocks)
     64            .Case("cplusplus", LangOpts.CPlusPlus)
     65            .Case("cplusplus11", LangOpts.CPlusPlus11)
     66            .Case("objc", LangOpts.ObjC1)
     67            .Case("objc_arc", LangOpts.ObjCAutoRefCount)
     68            .Case("opencl", LangOpts.OpenCL)
     69            .Case("tls", Target.isTLSSupported())
     70            .Default(Target.hasFeature(Feature));
     71 }
     72 
     73 bool
     74 Module::isAvailable(const LangOptions &LangOpts, const TargetInfo &Target,
     75                     Requirement &Req, HeaderDirective &MissingHeader) const {
     76   if (IsAvailable)
     77     return true;
     78 
     79   for (const Module *Current = this; Current; Current = Current->Parent) {
     80     if (!Current->MissingHeaders.empty()) {
     81       MissingHeader = Current->MissingHeaders.front();
     82       return false;
     83     }
     84     for (unsigned I = 0, N = Current->Requirements.size(); I != N; ++I) {
     85       if (hasFeature(Current->Requirements[I].first, LangOpts, Target) !=
     86               Current->Requirements[I].second) {
     87         Req = Current->Requirements[I];
     88         return false;
     89       }
     90     }
     91   }
     92 
     93   llvm_unreachable("could not find a reason why module is unavailable");
     94 }
     95 
     96 bool Module::isSubModuleOf(const Module *Other) const {
     97   const Module *This = this;
     98   do {
     99     if (This == Other)
    100       return true;
    101 
    102     This = This->Parent;
    103   } while (This);
    104 
    105   return false;
    106 }
    107 
    108 const Module *Module::getTopLevelModule() const {
    109   const Module *Result = this;
    110   while (Result->Parent)
    111     Result = Result->Parent;
    112 
    113   return Result;
    114 }
    115 
    116 std::string Module::getFullModuleName() const {
    117   SmallVector<StringRef, 2> Names;
    118 
    119   // Build up the set of module names (from innermost to outermost).
    120   for (const Module *M = this; M; M = M->Parent)
    121     Names.push_back(M->Name);
    122 
    123   std::string Result;
    124   for (SmallVectorImpl<StringRef>::reverse_iterator I = Names.rbegin(),
    125                                                  IEnd = Names.rend();
    126        I != IEnd; ++I) {
    127     if (!Result.empty())
    128       Result += '.';
    129 
    130     Result += *I;
    131   }
    132 
    133   return Result;
    134 }
    135 
    136 const DirectoryEntry *Module::getUmbrellaDir() const {
    137   if (const FileEntry *Header = getUmbrellaHeader())
    138     return Header->getDir();
    139 
    140   return Umbrella.dyn_cast<const DirectoryEntry *>();
    141 }
    142 
    143 ArrayRef<const FileEntry *> Module::getTopHeaders(FileManager &FileMgr) {
    144   if (!TopHeaderNames.empty()) {
    145     for (std::vector<std::string>::iterator
    146            I = TopHeaderNames.begin(), E = TopHeaderNames.end(); I != E; ++I) {
    147       if (const FileEntry *FE = FileMgr.getFile(*I))
    148         TopHeaders.insert(FE);
    149     }
    150     TopHeaderNames.clear();
    151   }
    152 
    153   return llvm::makeArrayRef(TopHeaders.begin(), TopHeaders.end());
    154 }
    155 
    156 void Module::addRequirement(StringRef Feature, bool RequiredState,
    157                             const LangOptions &LangOpts,
    158                             const TargetInfo &Target) {
    159   Requirements.push_back(Requirement(Feature, RequiredState));
    160 
    161   // If this feature is currently available, we're done.
    162   if (hasFeature(Feature, LangOpts, Target) == RequiredState)
    163     return;
    164 
    165   markUnavailable(/*MissingRequirement*/true);
    166 }
    167 
    168 void Module::markUnavailable(bool MissingRequirement) {
    169   if (!IsAvailable)
    170     return;
    171 
    172   SmallVector<Module *, 2> Stack;
    173   Stack.push_back(this);
    174   while (!Stack.empty()) {
    175     Module *Current = Stack.back();
    176     Stack.pop_back();
    177 
    178     if (!Current->IsAvailable)
    179       continue;
    180 
    181     Current->IsAvailable = false;
    182     Current->IsMissingRequirement |= MissingRequirement;
    183     for (submodule_iterator Sub = Current->submodule_begin(),
    184                          SubEnd = Current->submodule_end();
    185          Sub != SubEnd; ++Sub) {
    186       if ((*Sub)->IsAvailable)
    187         Stack.push_back(*Sub);
    188     }
    189   }
    190 }
    191 
    192 Module *Module::findSubmodule(StringRef Name) const {
    193   llvm::StringMap<unsigned>::const_iterator Pos = SubModuleIndex.find(Name);
    194   if (Pos == SubModuleIndex.end())
    195     return nullptr;
    196 
    197   return SubModules[Pos->getValue()];
    198 }
    199 
    200 static void printModuleId(raw_ostream &OS, const ModuleId &Id) {
    201   for (unsigned I = 0, N = Id.size(); I != N; ++I) {
    202     if (I)
    203       OS << ".";
    204     OS << Id[I].first;
    205   }
    206 }
    207 
    208 void Module::getExportedModules(SmallVectorImpl<Module *> &Exported) const {
    209   // All non-explicit submodules are exported.
    210   for (std::vector<Module *>::const_iterator I = SubModules.begin(),
    211                                              E = SubModules.end();
    212        I != E; ++I) {
    213     Module *Mod = *I;
    214     if (!Mod->IsExplicit)
    215       Exported.push_back(Mod);
    216   }
    217 
    218   // Find re-exported modules by filtering the list of imported modules.
    219   bool AnyWildcard = false;
    220   bool UnrestrictedWildcard = false;
    221   SmallVector<Module *, 4> WildcardRestrictions;
    222   for (unsigned I = 0, N = Exports.size(); I != N; ++I) {
    223     Module *Mod = Exports[I].getPointer();
    224     if (!Exports[I].getInt()) {
    225       // Export a named module directly; no wildcards involved.
    226       Exported.push_back(Mod);
    227 
    228       continue;
    229     }
    230 
    231     // Wildcard export: export all of the imported modules that match
    232     // the given pattern.
    233     AnyWildcard = true;
    234     if (UnrestrictedWildcard)
    235       continue;
    236 
    237     if (Module *Restriction = Exports[I].getPointer())
    238       WildcardRestrictions.push_back(Restriction);
    239     else {
    240       WildcardRestrictions.clear();
    241       UnrestrictedWildcard = true;
    242     }
    243   }
    244 
    245   // If there were any wildcards, push any imported modules that were
    246   // re-exported by the wildcard restriction.
    247   if (!AnyWildcard)
    248     return;
    249 
    250   for (unsigned I = 0, N = Imports.size(); I != N; ++I) {
    251     Module *Mod = Imports[I];
    252     bool Acceptable = UnrestrictedWildcard;
    253     if (!Acceptable) {
    254       // Check whether this module meets one of the restrictions.
    255       for (unsigned R = 0, NR = WildcardRestrictions.size(); R != NR; ++R) {
    256         Module *Restriction = WildcardRestrictions[R];
    257         if (Mod == Restriction || Mod->isSubModuleOf(Restriction)) {
    258           Acceptable = true;
    259           break;
    260         }
    261       }
    262     }
    263 
    264     if (!Acceptable)
    265       continue;
    266 
    267     Exported.push_back(Mod);
    268   }
    269 }
    270 
    271 void Module::buildVisibleModulesCache() const {
    272   assert(VisibleModulesCache.empty() && "cache does not need building");
    273 
    274   // This module is visible to itself.
    275   VisibleModulesCache.insert(this);
    276 
    277   // Every imported module is visible.
    278   SmallVector<Module *, 16> Stack(Imports.begin(), Imports.end());
    279   while (!Stack.empty()) {
    280     Module *CurrModule = Stack.pop_back_val();
    281 
    282     // Every module transitively exported by an imported module is visible.
    283     if (VisibleModulesCache.insert(CurrModule).second)
    284       CurrModule->getExportedModules(Stack);
    285   }
    286 }
    287 
    288 void Module::print(raw_ostream &OS, unsigned Indent) const {
    289   OS.indent(Indent);
    290   if (IsFramework)
    291     OS << "framework ";
    292   if (IsExplicit)
    293     OS << "explicit ";
    294   OS << "module " << Name;
    295 
    296   if (IsSystem) {
    297     OS.indent(Indent + 2);
    298     OS << " [system]";
    299   }
    300 
    301   OS << " {\n";
    302 
    303   if (!Requirements.empty()) {
    304     OS.indent(Indent + 2);
    305     OS << "requires ";
    306     for (unsigned I = 0, N = Requirements.size(); I != N; ++I) {
    307       if (I)
    308         OS << ", ";
    309       if (!Requirements[I].second)
    310         OS << "!";
    311       OS << Requirements[I].first;
    312     }
    313     OS << "\n";
    314   }
    315 
    316   if (const FileEntry *UmbrellaHeader = getUmbrellaHeader()) {
    317     OS.indent(Indent + 2);
    318     OS << "umbrella header \"";
    319     OS.write_escaped(UmbrellaHeader->getName());
    320     OS << "\"\n";
    321   } else if (const DirectoryEntry *UmbrellaDir = getUmbrellaDir()) {
    322     OS.indent(Indent + 2);
    323     OS << "umbrella \"";
    324     OS.write_escaped(UmbrellaDir->getName());
    325     OS << "\"\n";
    326   }
    327 
    328   if (!ConfigMacros.empty() || ConfigMacrosExhaustive) {
    329     OS.indent(Indent + 2);
    330     OS << "config_macros ";
    331     if (ConfigMacrosExhaustive)
    332       OS << "[exhaustive]";
    333     for (unsigned I = 0, N = ConfigMacros.size(); I != N; ++I) {
    334       if (I)
    335         OS << ", ";
    336       OS << ConfigMacros[I];
    337     }
    338     OS << "\n";
    339   }
    340 
    341   for (unsigned I = 0, N = NormalHeaders.size(); I != N; ++I) {
    342     OS.indent(Indent + 2);
    343     OS << "header \"";
    344     OS.write_escaped(NormalHeaders[I]->getName());
    345     OS << "\"\n";
    346   }
    347 
    348   for (unsigned I = 0, N = ExcludedHeaders.size(); I != N; ++I) {
    349     OS.indent(Indent + 2);
    350     OS << "exclude header \"";
    351     OS.write_escaped(ExcludedHeaders[I]->getName());
    352     OS << "\"\n";
    353   }
    354 
    355   for (unsigned I = 0, N = PrivateHeaders.size(); I != N; ++I) {
    356     OS.indent(Indent + 2);
    357     OS << "private header \"";
    358     OS.write_escaped(PrivateHeaders[I]->getName());
    359     OS << "\"\n";
    360   }
    361 
    362   for (submodule_const_iterator MI = submodule_begin(), MIEnd = submodule_end();
    363        MI != MIEnd; ++MI)
    364     if (!(*MI)->IsInferred)
    365       (*MI)->print(OS, Indent + 2);
    366 
    367   for (unsigned I = 0, N = Exports.size(); I != N; ++I) {
    368     OS.indent(Indent + 2);
    369     OS << "export ";
    370     if (Module *Restriction = Exports[I].getPointer()) {
    371       OS << Restriction->getFullModuleName();
    372       if (Exports[I].getInt())
    373         OS << ".*";
    374     } else {
    375       OS << "*";
    376     }
    377     OS << "\n";
    378   }
    379 
    380   for (unsigned I = 0, N = UnresolvedExports.size(); I != N; ++I) {
    381     OS.indent(Indent + 2);
    382     OS << "export ";
    383     printModuleId(OS, UnresolvedExports[I].Id);
    384     if (UnresolvedExports[I].Wildcard) {
    385       if (UnresolvedExports[I].Id.empty())
    386         OS << "*";
    387       else
    388         OS << ".*";
    389     }
    390     OS << "\n";
    391   }
    392 
    393   for (unsigned I = 0, N = DirectUses.size(); I != N; ++I) {
    394     OS.indent(Indent + 2);
    395     OS << "use ";
    396     OS << DirectUses[I]->getFullModuleName();
    397     OS << "\n";
    398   }
    399 
    400   for (unsigned I = 0, N = UnresolvedDirectUses.size(); I != N; ++I) {
    401     OS.indent(Indent + 2);
    402     OS << "use ";
    403     printModuleId(OS, UnresolvedDirectUses[I]);
    404     OS << "\n";
    405   }
    406 
    407   for (unsigned I = 0, N = LinkLibraries.size(); I != N; ++I) {
    408     OS.indent(Indent + 2);
    409     OS << "link ";
    410     if (LinkLibraries[I].IsFramework)
    411       OS << "framework ";
    412     OS << "\"";
    413     OS.write_escaped(LinkLibraries[I].Library);
    414     OS << "\"";
    415   }
    416 
    417   for (unsigned I = 0, N = UnresolvedConflicts.size(); I != N; ++I) {
    418     OS.indent(Indent + 2);
    419     OS << "conflict ";
    420     printModuleId(OS, UnresolvedConflicts[I].Id);
    421     OS << ", \"";
    422     OS.write_escaped(UnresolvedConflicts[I].Message);
    423     OS << "\"\n";
    424   }
    425 
    426   for (unsigned I = 0, N = Conflicts.size(); I != N; ++I) {
    427     OS.indent(Indent + 2);
    428     OS << "conflict ";
    429     OS << Conflicts[I].Other->getFullModuleName();
    430     OS << ", \"";
    431     OS.write_escaped(Conflicts[I].Message);
    432     OS << "\"\n";
    433   }
    434 
    435   if (InferSubmodules) {
    436     OS.indent(Indent + 2);
    437     if (InferExplicitSubmodules)
    438       OS << "explicit ";
    439     OS << "module * {\n";
    440     if (InferExportWildcard) {
    441       OS.indent(Indent + 4);
    442       OS << "export *\n";
    443     }
    444     OS.indent(Indent + 2);
    445     OS << "}\n";
    446   }
    447 
    448   OS.indent(Indent);
    449   OS << "}\n";
    450 }
    451 
    452 void Module::dump() const {
    453   print(llvm::errs());
    454 }
    455 
    456 
    457