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 
Module(StringRef Name,SourceLocation DefinitionLoc,Module * Parent,bool IsFramework,bool IsExplicit)27 Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
28                bool IsFramework, bool IsExplicit)
29     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent), Directory(),
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 
~Module()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.
hasFeature(StringRef Feature,const LangOptions & LangOpts,const TargetInfo & Target)59 static bool hasFeature(StringRef Feature, const LangOptions &LangOpts,
60                        const TargetInfo &Target) {
61   bool HasFeature = 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   if (!HasFeature)
72     HasFeature = std::find(LangOpts.ModuleFeatures.begin(),
73                            LangOpts.ModuleFeatures.end(),
74                            Feature) != LangOpts.ModuleFeatures.end();
75   return HasFeature;
76 }
77 
isAvailable(const LangOptions & LangOpts,const TargetInfo & Target,Requirement & Req,UnresolvedHeaderDirective & MissingHeader) const78 bool Module::isAvailable(const LangOptions &LangOpts, const TargetInfo &Target,
79                          Requirement &Req,
80                          UnresolvedHeaderDirective &MissingHeader) const {
81   if (IsAvailable)
82     return true;
83 
84   for (const Module *Current = this; Current; Current = Current->Parent) {
85     if (!Current->MissingHeaders.empty()) {
86       MissingHeader = Current->MissingHeaders.front();
87       return false;
88     }
89     for (unsigned I = 0, N = Current->Requirements.size(); I != N; ++I) {
90       if (hasFeature(Current->Requirements[I].first, LangOpts, Target) !=
91               Current->Requirements[I].second) {
92         Req = Current->Requirements[I];
93         return false;
94       }
95     }
96   }
97 
98   llvm_unreachable("could not find a reason why module is unavailable");
99 }
100 
isSubModuleOf(const Module * Other) const101 bool Module::isSubModuleOf(const Module *Other) const {
102   const Module *This = this;
103   do {
104     if (This == Other)
105       return true;
106 
107     This = This->Parent;
108   } while (This);
109 
110   return false;
111 }
112 
getTopLevelModule() const113 const Module *Module::getTopLevelModule() const {
114   const Module *Result = this;
115   while (Result->Parent)
116     Result = Result->Parent;
117 
118   return Result;
119 }
120 
getFullModuleName() const121 std::string Module::getFullModuleName() const {
122   SmallVector<StringRef, 2> Names;
123 
124   // Build up the set of module names (from innermost to outermost).
125   for (const Module *M = this; M; M = M->Parent)
126     Names.push_back(M->Name);
127 
128   std::string Result;
129   for (SmallVectorImpl<StringRef>::reverse_iterator I = Names.rbegin(),
130                                                  IEnd = Names.rend();
131        I != IEnd; ++I) {
132     if (!Result.empty())
133       Result += '.';
134 
135     Result += *I;
136   }
137 
138   return Result;
139 }
140 
getUmbrellaDir() const141 const DirectoryEntry *Module::getUmbrellaDir() const {
142   if (const FileEntry *Header = getUmbrellaHeader())
143     return Header->getDir();
144 
145   return Umbrella.dyn_cast<const DirectoryEntry *>();
146 }
147 
getTopHeaders(FileManager & FileMgr)148 ArrayRef<const FileEntry *> Module::getTopHeaders(FileManager &FileMgr) {
149   if (!TopHeaderNames.empty()) {
150     for (std::vector<std::string>::iterator
151            I = TopHeaderNames.begin(), E = TopHeaderNames.end(); I != E; ++I) {
152       if (const FileEntry *FE = FileMgr.getFile(*I))
153         TopHeaders.insert(FE);
154     }
155     TopHeaderNames.clear();
156   }
157 
158   return llvm::makeArrayRef(TopHeaders.begin(), TopHeaders.end());
159 }
160 
directlyUses(const Module * Requested) const161 bool Module::directlyUses(const Module *Requested) const {
162   auto *Top = getTopLevelModule();
163 
164   // A top-level module implicitly uses itself.
165   if (Requested->isSubModuleOf(Top))
166     return true;
167 
168   for (auto *Use : Top->DirectUses)
169     if (Requested->isSubModuleOf(Use))
170       return true;
171   return false;
172 }
173 
addRequirement(StringRef Feature,bool RequiredState,const LangOptions & LangOpts,const TargetInfo & Target)174 void Module::addRequirement(StringRef Feature, bool RequiredState,
175                             const LangOptions &LangOpts,
176                             const TargetInfo &Target) {
177   Requirements.push_back(Requirement(Feature, RequiredState));
178 
179   // If this feature is currently available, we're done.
180   if (hasFeature(Feature, LangOpts, Target) == RequiredState)
181     return;
182 
183   markUnavailable(/*MissingRequirement*/true);
184 }
185 
markUnavailable(bool MissingRequirement)186 void Module::markUnavailable(bool MissingRequirement) {
187   if (!IsAvailable)
188     return;
189 
190   SmallVector<Module *, 2> Stack;
191   Stack.push_back(this);
192   while (!Stack.empty()) {
193     Module *Current = Stack.back();
194     Stack.pop_back();
195 
196     if (!Current->IsAvailable)
197       continue;
198 
199     Current->IsAvailable = false;
200     Current->IsMissingRequirement |= MissingRequirement;
201     for (submodule_iterator Sub = Current->submodule_begin(),
202                          SubEnd = Current->submodule_end();
203          Sub != SubEnd; ++Sub) {
204       if ((*Sub)->IsAvailable)
205         Stack.push_back(*Sub);
206     }
207   }
208 }
209 
findSubmodule(StringRef Name) const210 Module *Module::findSubmodule(StringRef Name) const {
211   llvm::StringMap<unsigned>::const_iterator Pos = SubModuleIndex.find(Name);
212   if (Pos == SubModuleIndex.end())
213     return nullptr;
214 
215   return SubModules[Pos->getValue()];
216 }
217 
printModuleId(raw_ostream & OS,const ModuleId & Id)218 static void printModuleId(raw_ostream &OS, const ModuleId &Id) {
219   for (unsigned I = 0, N = Id.size(); I != N; ++I) {
220     if (I)
221       OS << ".";
222     OS << Id[I].first;
223   }
224 }
225 
getExportedModules(SmallVectorImpl<Module * > & Exported) const226 void Module::getExportedModules(SmallVectorImpl<Module *> &Exported) const {
227   // All non-explicit submodules are exported.
228   for (std::vector<Module *>::const_iterator I = SubModules.begin(),
229                                              E = SubModules.end();
230        I != E; ++I) {
231     Module *Mod = *I;
232     if (!Mod->IsExplicit)
233       Exported.push_back(Mod);
234   }
235 
236   // Find re-exported modules by filtering the list of imported modules.
237   bool AnyWildcard = false;
238   bool UnrestrictedWildcard = false;
239   SmallVector<Module *, 4> WildcardRestrictions;
240   for (unsigned I = 0, N = Exports.size(); I != N; ++I) {
241     Module *Mod = Exports[I].getPointer();
242     if (!Exports[I].getInt()) {
243       // Export a named module directly; no wildcards involved.
244       Exported.push_back(Mod);
245 
246       continue;
247     }
248 
249     // Wildcard export: export all of the imported modules that match
250     // the given pattern.
251     AnyWildcard = true;
252     if (UnrestrictedWildcard)
253       continue;
254 
255     if (Module *Restriction = Exports[I].getPointer())
256       WildcardRestrictions.push_back(Restriction);
257     else {
258       WildcardRestrictions.clear();
259       UnrestrictedWildcard = true;
260     }
261   }
262 
263   // If there were any wildcards, push any imported modules that were
264   // re-exported by the wildcard restriction.
265   if (!AnyWildcard)
266     return;
267 
268   for (unsigned I = 0, N = Imports.size(); I != N; ++I) {
269     Module *Mod = Imports[I];
270     bool Acceptable = UnrestrictedWildcard;
271     if (!Acceptable) {
272       // Check whether this module meets one of the restrictions.
273       for (unsigned R = 0, NR = WildcardRestrictions.size(); R != NR; ++R) {
274         Module *Restriction = WildcardRestrictions[R];
275         if (Mod == Restriction || Mod->isSubModuleOf(Restriction)) {
276           Acceptable = true;
277           break;
278         }
279       }
280     }
281 
282     if (!Acceptable)
283       continue;
284 
285     Exported.push_back(Mod);
286   }
287 }
288 
buildVisibleModulesCache() const289 void Module::buildVisibleModulesCache() const {
290   assert(VisibleModulesCache.empty() && "cache does not need building");
291 
292   // This module is visible to itself.
293   VisibleModulesCache.insert(this);
294 
295   // Every imported module is visible.
296   SmallVector<Module *, 16> Stack(Imports.begin(), Imports.end());
297   while (!Stack.empty()) {
298     Module *CurrModule = Stack.pop_back_val();
299 
300     // Every module transitively exported by an imported module is visible.
301     if (VisibleModulesCache.insert(CurrModule).second)
302       CurrModule->getExportedModules(Stack);
303   }
304 }
305 
print(raw_ostream & OS,unsigned Indent) const306 void Module::print(raw_ostream &OS, unsigned Indent) const {
307   OS.indent(Indent);
308   if (IsFramework)
309     OS << "framework ";
310   if (IsExplicit)
311     OS << "explicit ";
312   OS << "module " << Name;
313 
314   if (IsSystem || IsExternC) {
315     OS.indent(Indent + 2);
316     if (IsSystem)
317       OS << " [system]";
318     if (IsExternC)
319       OS << " [extern_c]";
320   }
321 
322   OS << " {\n";
323 
324   if (!Requirements.empty()) {
325     OS.indent(Indent + 2);
326     OS << "requires ";
327     for (unsigned I = 0, N = Requirements.size(); I != N; ++I) {
328       if (I)
329         OS << ", ";
330       if (!Requirements[I].second)
331         OS << "!";
332       OS << Requirements[I].first;
333     }
334     OS << "\n";
335   }
336 
337   if (const FileEntry *UmbrellaHeader = getUmbrellaHeader()) {
338     OS.indent(Indent + 2);
339     OS << "umbrella header \"";
340     OS.write_escaped(UmbrellaHeader->getName());
341     OS << "\"\n";
342   } else if (const DirectoryEntry *UmbrellaDir = getUmbrellaDir()) {
343     OS.indent(Indent + 2);
344     OS << "umbrella \"";
345     OS.write_escaped(UmbrellaDir->getName());
346     OS << "\"\n";
347   }
348 
349   if (!ConfigMacros.empty() || ConfigMacrosExhaustive) {
350     OS.indent(Indent + 2);
351     OS << "config_macros ";
352     if (ConfigMacrosExhaustive)
353       OS << "[exhaustive]";
354     for (unsigned I = 0, N = ConfigMacros.size(); I != N; ++I) {
355       if (I)
356         OS << ", ";
357       OS << ConfigMacros[I];
358     }
359     OS << "\n";
360   }
361 
362   struct {
363     StringRef Prefix;
364     HeaderKind Kind;
365   } Kinds[] = {{"", HK_Normal},
366                {"textual ", HK_Textual},
367                {"private ", HK_Private},
368                {"private textual ", HK_PrivateTextual},
369                {"exclude ", HK_Excluded}};
370 
371   for (auto &K : Kinds) {
372     for (auto &H : Headers[K.Kind]) {
373       OS.indent(Indent + 2);
374       OS << K.Prefix << "header \"";
375       OS.write_escaped(H.NameAsWritten);
376       OS << "\"\n";
377     }
378   }
379 
380   for (submodule_const_iterator MI = submodule_begin(), MIEnd = submodule_end();
381        MI != MIEnd; ++MI)
382     // Print inferred subframework modules so that we don't need to re-infer
383     // them (requires expensive directory iteration + stat calls) when we build
384     // the module. Regular inferred submodules are OK, as we need to look at all
385     // those header files anyway.
386     if (!(*MI)->IsInferred || (*MI)->IsFramework)
387       (*MI)->print(OS, Indent + 2);
388 
389   for (unsigned I = 0, N = Exports.size(); I != N; ++I) {
390     OS.indent(Indent + 2);
391     OS << "export ";
392     if (Module *Restriction = Exports[I].getPointer()) {
393       OS << Restriction->getFullModuleName();
394       if (Exports[I].getInt())
395         OS << ".*";
396     } else {
397       OS << "*";
398     }
399     OS << "\n";
400   }
401 
402   for (unsigned I = 0, N = UnresolvedExports.size(); I != N; ++I) {
403     OS.indent(Indent + 2);
404     OS << "export ";
405     printModuleId(OS, UnresolvedExports[I].Id);
406     if (UnresolvedExports[I].Wildcard) {
407       if (UnresolvedExports[I].Id.empty())
408         OS << "*";
409       else
410         OS << ".*";
411     }
412     OS << "\n";
413   }
414 
415   for (unsigned I = 0, N = DirectUses.size(); I != N; ++I) {
416     OS.indent(Indent + 2);
417     OS << "use ";
418     OS << DirectUses[I]->getFullModuleName();
419     OS << "\n";
420   }
421 
422   for (unsigned I = 0, N = UnresolvedDirectUses.size(); I != N; ++I) {
423     OS.indent(Indent + 2);
424     OS << "use ";
425     printModuleId(OS, UnresolvedDirectUses[I]);
426     OS << "\n";
427   }
428 
429   for (unsigned I = 0, N = LinkLibraries.size(); I != N; ++I) {
430     OS.indent(Indent + 2);
431     OS << "link ";
432     if (LinkLibraries[I].IsFramework)
433       OS << "framework ";
434     OS << "\"";
435     OS.write_escaped(LinkLibraries[I].Library);
436     OS << "\"";
437   }
438 
439   for (unsigned I = 0, N = UnresolvedConflicts.size(); I != N; ++I) {
440     OS.indent(Indent + 2);
441     OS << "conflict ";
442     printModuleId(OS, UnresolvedConflicts[I].Id);
443     OS << ", \"";
444     OS.write_escaped(UnresolvedConflicts[I].Message);
445     OS << "\"\n";
446   }
447 
448   for (unsigned I = 0, N = Conflicts.size(); I != N; ++I) {
449     OS.indent(Indent + 2);
450     OS << "conflict ";
451     OS << Conflicts[I].Other->getFullModuleName();
452     OS << ", \"";
453     OS.write_escaped(Conflicts[I].Message);
454     OS << "\"\n";
455   }
456 
457   if (InferSubmodules) {
458     OS.indent(Indent + 2);
459     if (InferExplicitSubmodules)
460       OS << "explicit ";
461     OS << "module * {\n";
462     if (InferExportWildcard) {
463       OS.indent(Indent + 4);
464       OS << "export *\n";
465     }
466     OS.indent(Indent + 2);
467     OS << "}\n";
468   }
469 
470   OS.indent(Indent);
471   OS << "}\n";
472 }
473 
dump() const474 void Module::dump() const {
475   print(llvm::errs());
476 }
477 
478 
479