1 //===--- Module.h - Describe a module ---------------------------*- C++ -*-===//
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 #include "clang/Basic/Module.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/LangOptions.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include "llvm/Support/raw_ostream.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/StringSwitch.h"
21 using namespace clang;
22 
23 Module::Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent,
24                bool IsFramework, bool IsExplicit)
25   : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent),
26     Umbrella(), IsAvailable(true), IsFromModuleFile(false),
27     IsFramework(IsFramework), IsExplicit(IsExplicit), InferSubmodules(false),
28     InferExplicitSubmodules(false), InferExportWildcard(false),
29     NameVisibility(Hidden)
30 {
31   if (Parent) {
32     if (!Parent->isAvailable())
33       IsAvailable = false;
34 
35     Parent->SubModuleIndex[Name] = Parent->SubModules.size();
36     Parent->SubModules.push_back(this);
37   }
38 }
39 
40 Module::~Module() {
41   for (submodule_iterator I = submodule_begin(), IEnd = submodule_end();
42        I != IEnd; ++I) {
43     delete *I;
44   }
45 
46 }
47 
48 /// \brief Determine whether a translation unit built using the current
49 /// language options has the given feature.
50 static bool hasFeature(StringRef Feature, const LangOptions &LangOpts) {
51   return llvm::StringSwitch<bool>(Feature)
52            .Case("blocks", LangOpts.Blocks)
53            .Case("cplusplus", LangOpts.CPlusPlus)
54            .Case("cplusplus11", LangOpts.CPlusPlus0x)
55            .Case("objc", LangOpts.ObjC1)
56            .Case("objc_arc", LangOpts.ObjCAutoRefCount)
57            .Default(false);
58 }
59 
60 bool
61 Module::isAvailable(const LangOptions &LangOpts, StringRef &Feature) const {
62   if (IsAvailable)
63     return true;
64 
65   for (const Module *Current = this; Current; Current = Current->Parent) {
66     for (unsigned I = 0, N = Current->Requires.size(); I != N; ++I) {
67       if (!hasFeature(Current->Requires[I], LangOpts)) {
68         Feature = Current->Requires[I];
69         return false;
70       }
71     }
72   }
73 
74   llvm_unreachable("could not find a reason why module is unavailable");
75 }
76 
77 bool Module::isSubModuleOf(Module *Other) const {
78   const Module *This = this;
79   do {
80     if (This == Other)
81       return true;
82 
83     This = This->Parent;
84   } while (This);
85 
86   return false;
87 }
88 
89 const Module *Module::getTopLevelModule() const {
90   const Module *Result = this;
91   while (Result->Parent)
92     Result = Result->Parent;
93 
94   return Result;
95 }
96 
97 std::string Module::getFullModuleName() const {
98   llvm::SmallVector<StringRef, 2> Names;
99 
100   // Build up the set of module names (from innermost to outermost).
101   for (const Module *M = this; M; M = M->Parent)
102     Names.push_back(M->Name);
103 
104   std::string Result;
105   for (llvm::SmallVector<StringRef, 2>::reverse_iterator I = Names.rbegin(),
106                                                       IEnd = Names.rend();
107        I != IEnd; ++I) {
108     if (!Result.empty())
109       Result += '.';
110 
111     Result += *I;
112   }
113 
114   return Result;
115 }
116 
117 const DirectoryEntry *Module::getUmbrellaDir() const {
118   if (const FileEntry *Header = getUmbrellaHeader())
119     return Header->getDir();
120 
121   return Umbrella.dyn_cast<const DirectoryEntry *>();
122 }
123 
124 void Module::addRequirement(StringRef Feature, const LangOptions &LangOpts) {
125   Requires.push_back(Feature);
126 
127   // If this feature is currently available, we're done.
128   if (hasFeature(Feature, LangOpts))
129     return;
130 
131   if (!IsAvailable)
132     return;
133 
134   llvm::SmallVector<Module *, 2> Stack;
135   Stack.push_back(this);
136   while (!Stack.empty()) {
137     Module *Current = Stack.back();
138     Stack.pop_back();
139 
140     if (!Current->IsAvailable)
141       continue;
142 
143     Current->IsAvailable = false;
144     for (submodule_iterator Sub = Current->submodule_begin(),
145                          SubEnd = Current->submodule_end();
146          Sub != SubEnd; ++Sub) {
147       if ((*Sub)->IsAvailable)
148         Stack.push_back(*Sub);
149     }
150   }
151 }
152 
153 Module *Module::findSubmodule(StringRef Name) const {
154   llvm::StringMap<unsigned>::const_iterator Pos = SubModuleIndex.find(Name);
155   if (Pos == SubModuleIndex.end())
156     return 0;
157 
158   return SubModules[Pos->getValue()];
159 }
160 
161 static void printModuleId(llvm::raw_ostream &OS, const ModuleId &Id) {
162   for (unsigned I = 0, N = Id.size(); I != N; ++I) {
163     if (I)
164       OS << ".";
165     OS << Id[I].first;
166   }
167 }
168 
169 void Module::print(llvm::raw_ostream &OS, unsigned Indent) const {
170   OS.indent(Indent);
171   if (IsFramework)
172     OS << "framework ";
173   if (IsExplicit)
174     OS << "explicit ";
175   OS << "module " << Name << " {\n";
176 
177   if (!Requires.empty()) {
178     OS.indent(Indent + 2);
179     OS << "requires ";
180     for (unsigned I = 0, N = Requires.size(); I != N; ++I) {
181       if (I)
182         OS << ", ";
183       OS << Requires[I];
184     }
185     OS << "\n";
186   }
187 
188   if (const FileEntry *UmbrellaHeader = getUmbrellaHeader()) {
189     OS.indent(Indent + 2);
190     OS << "umbrella header \"";
191     OS.write_escaped(UmbrellaHeader->getName());
192     OS << "\"\n";
193   } else if (const DirectoryEntry *UmbrellaDir = getUmbrellaDir()) {
194     OS.indent(Indent + 2);
195     OS << "umbrella \"";
196     OS.write_escaped(UmbrellaDir->getName());
197     OS << "\"\n";
198   }
199 
200   for (unsigned I = 0, N = Headers.size(); I != N; ++I) {
201     OS.indent(Indent + 2);
202     OS << "header \"";
203     OS.write_escaped(Headers[I]->getName());
204     OS << "\"\n";
205   }
206 
207   for (submodule_const_iterator MI = submodule_begin(), MIEnd = submodule_end();
208        MI != MIEnd; ++MI)
209     (*MI)->print(OS, Indent + 2);
210 
211   for (unsigned I = 0, N = Exports.size(); I != N; ++I) {
212     OS.indent(Indent + 2);
213     OS << "export ";
214     if (Module *Restriction = Exports[I].getPointer()) {
215       OS << Restriction->getFullModuleName();
216       if (Exports[I].getInt())
217         OS << ".*";
218     } else {
219       OS << "*";
220     }
221     OS << "\n";
222   }
223 
224   for (unsigned I = 0, N = UnresolvedExports.size(); I != N; ++I) {
225     OS.indent(Indent + 2);
226     OS << "export ";
227     printModuleId(OS, UnresolvedExports[I].Id);
228     if (UnresolvedExports[I].Wildcard) {
229       if (UnresolvedExports[I].Id.empty())
230         OS << "*";
231       else
232         OS << ".*";
233     }
234     OS << "\n";
235   }
236 
237   if (InferSubmodules) {
238     OS.indent(Indent + 2);
239     if (InferExplicitSubmodules)
240       OS << "explicit ";
241     OS << "module * {\n";
242     if (InferExportWildcard) {
243       OS.indent(Indent + 4);
244       OS << "export *\n";
245     }
246     OS.indent(Indent + 2);
247     OS << "}\n";
248   }
249 
250   OS.indent(Indent);
251   OS << "}\n";
252 }
253 
254 void Module::dump() const {
255   print(llvm::errs());
256 }
257 
258 
259