1 //===- IndexingAction.cpp - Frontend index action -------------------------===//
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 #include "clang/Index/IndexingAction.h"
10 #include "IndexingContext.h"
11 #include "clang/Frontend/CompilerInstance.h"
12 #include "clang/Frontend/FrontendAction.h"
13 #include "clang/Frontend/MultiplexConsumer.h"
14 #include "clang/Index/IndexDataConsumer.h"
15 #include "clang/Lex/PPCallbacks.h"
16 #include "clang/Lex/Preprocessor.h"
17 #include "clang/Serialization/ASTReader.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include <memory>
20 
21 using namespace clang;
22 using namespace clang::index;
23 
24 namespace {
25 
26 class IndexPPCallbacks final : public PPCallbacks {
27   std::shared_ptr<IndexingContext> IndexCtx;
28 
29 public:
30   IndexPPCallbacks(std::shared_ptr<IndexingContext> IndexCtx)
31       : IndexCtx(std::move(IndexCtx)) {}
32 
33   void MacroExpands(const Token &MacroNameTok, const MacroDefinition &MD,
34                     SourceRange Range, const MacroArgs *Args) override {
35     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
36                                    Range.getBegin(), *MD.getMacroInfo());
37   }
38 
39   void MacroDefined(const Token &MacroNameTok,
40                     const MacroDirective *MD) override {
41     IndexCtx->handleMacroDefined(*MacroNameTok.getIdentifierInfo(),
42                                  MacroNameTok.getLocation(),
43                                  *MD->getMacroInfo());
44   }
45 
46   void MacroUndefined(const Token &MacroNameTok, const MacroDefinition &MD,
47                       const MacroDirective *Undef) override {
48     if (!MD.getMacroInfo())  // Ignore noop #undef.
49       return;
50     IndexCtx->handleMacroUndefined(*MacroNameTok.getIdentifierInfo(),
51                                    MacroNameTok.getLocation(),
52                                    *MD.getMacroInfo());
53   }
54 
55   void Defined(const Token &MacroNameTok, const MacroDefinition &MD,
56                SourceRange Range) override {
57     if (!MD.getMacroInfo()) // Ignore nonexistent macro.
58       return;
59     // Note: this is defined(M), not #define M
60     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
61                                    MacroNameTok.getLocation(),
62                                    *MD.getMacroInfo());
63   }
64   void Ifdef(SourceLocation Loc, const Token &MacroNameTok,
65              const MacroDefinition &MD) override {
66     if (!MD.getMacroInfo()) // Ignore non-existent macro.
67       return;
68     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
69                                    MacroNameTok.getLocation(),
70                                    *MD.getMacroInfo());
71   }
72   void Ifndef(SourceLocation Loc, const Token &MacroNameTok,
73               const MacroDefinition &MD) override {
74     if (!MD.getMacroInfo()) // Ignore nonexistent macro.
75       return;
76     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
77                                    MacroNameTok.getLocation(),
78                                    *MD.getMacroInfo());
79   }
80 
81   using PPCallbacks::Elifdef;
82   using PPCallbacks::Elifndef;
83   void Elifdef(SourceLocation Loc, const Token &MacroNameTok,
84                const MacroDefinition &MD) override {
85     if (!MD.getMacroInfo()) // Ignore non-existent macro.
86       return;
87     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
88                                    MacroNameTok.getLocation(),
89                                    *MD.getMacroInfo());
90   }
91   void Elifndef(SourceLocation Loc, const Token &MacroNameTok,
92                 const MacroDefinition &MD) override {
93     if (!MD.getMacroInfo()) // Ignore non-existent macro.
94       return;
95     IndexCtx->handleMacroReference(*MacroNameTok.getIdentifierInfo(),
96                                    MacroNameTok.getLocation(),
97                                    *MD.getMacroInfo());
98   }
99 };
100 
101 class IndexASTConsumer final : public ASTConsumer {
102   std::shared_ptr<IndexDataConsumer> DataConsumer;
103   std::shared_ptr<IndexingContext> IndexCtx;
104   std::shared_ptr<Preprocessor> PP;
105   std::function<bool(const Decl *)> ShouldSkipFunctionBody;
106 
107 public:
108   IndexASTConsumer(std::shared_ptr<IndexDataConsumer> DataConsumer,
109                    const IndexingOptions &Opts,
110                    std::shared_ptr<Preprocessor> PP,
111                    std::function<bool(const Decl *)> ShouldSkipFunctionBody)
112       : DataConsumer(std::move(DataConsumer)),
113         IndexCtx(new IndexingContext(Opts, *this->DataConsumer)),
114         PP(std::move(PP)),
115         ShouldSkipFunctionBody(std::move(ShouldSkipFunctionBody)) {
116     assert(this->DataConsumer != nullptr);
117     assert(this->PP != nullptr);
118   }
119 
120 protected:
121   void Initialize(ASTContext &Context) override {
122     IndexCtx->setASTContext(Context);
123     IndexCtx->getDataConsumer().initialize(Context);
124     IndexCtx->getDataConsumer().setPreprocessor(PP);
125     PP->addPPCallbacks(std::make_unique<IndexPPCallbacks>(IndexCtx));
126   }
127 
128   bool HandleTopLevelDecl(DeclGroupRef DG) override {
129     return IndexCtx->indexDeclGroupRef(DG);
130   }
131 
132   void HandleInterestingDecl(DeclGroupRef DG) override {
133     // Ignore deserialized decls.
134   }
135 
136   void HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) override {
137     IndexCtx->indexDeclGroupRef(DG);
138   }
139 
140   void HandleTranslationUnit(ASTContext &Ctx) override {
141     DataConsumer->finish();
142   }
143 
144   bool shouldSkipFunctionBody(Decl *D) override {
145     return ShouldSkipFunctionBody(D);
146   }
147 };
148 
149 class IndexAction final : public ASTFrontendAction {
150   std::shared_ptr<IndexDataConsumer> DataConsumer;
151   IndexingOptions Opts;
152 
153 public:
154   IndexAction(std::shared_ptr<IndexDataConsumer> DataConsumer,
155               const IndexingOptions &Opts)
156       : DataConsumer(std::move(DataConsumer)), Opts(Opts) {
157     assert(this->DataConsumer != nullptr);
158   }
159 
160 protected:
161   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
162                                                  StringRef InFile) override {
163     return std::make_unique<IndexASTConsumer>(
164         DataConsumer, Opts, CI.getPreprocessorPtr(),
165         /*ShouldSkipFunctionBody=*/[](const Decl *) { return false; });
166   }
167 };
168 
169 } // anonymous namespace
170 
171 std::unique_ptr<ASTConsumer> index::createIndexingASTConsumer(
172     std::shared_ptr<IndexDataConsumer> DataConsumer,
173     const IndexingOptions &Opts, std::shared_ptr<Preprocessor> PP,
174     std::function<bool(const Decl *)> ShouldSkipFunctionBody) {
175   return std::make_unique<IndexASTConsumer>(DataConsumer, Opts, PP,
176                                             ShouldSkipFunctionBody);
177 }
178 
179 std::unique_ptr<ASTConsumer> clang::index::createIndexingASTConsumer(
180     std::shared_ptr<IndexDataConsumer> DataConsumer,
181     const IndexingOptions &Opts, std::shared_ptr<Preprocessor> PP) {
182   std::function<bool(const Decl *)> ShouldSkipFunctionBody = [](const Decl *) {
183     return false;
184   };
185   if (Opts.ShouldTraverseDecl)
186     ShouldSkipFunctionBody =
187         [ShouldTraverseDecl(Opts.ShouldTraverseDecl)](const Decl *D) {
188           return !ShouldTraverseDecl(D);
189         };
190   return createIndexingASTConsumer(std::move(DataConsumer), Opts, std::move(PP),
191                                    std::move(ShouldSkipFunctionBody));
192 }
193 
194 std::unique_ptr<FrontendAction>
195 index::createIndexingAction(std::shared_ptr<IndexDataConsumer> DataConsumer,
196                             const IndexingOptions &Opts) {
197   assert(DataConsumer != nullptr);
198   return std::make_unique<IndexAction>(std::move(DataConsumer), Opts);
199 }
200 
201 static bool topLevelDeclVisitor(void *context, const Decl *D) {
202   IndexingContext &IndexCtx = *static_cast<IndexingContext*>(context);
203   return IndexCtx.indexTopLevelDecl(D);
204 }
205 
206 static void indexTranslationUnit(ASTUnit &Unit, IndexingContext &IndexCtx) {
207   Unit.visitLocalTopLevelDecls(&IndexCtx, topLevelDeclVisitor);
208 }
209 
210 static void indexPreprocessorMacro(const IdentifierInfo *II,
211                                    const MacroInfo *MI,
212                                    MacroDirective::Kind DirectiveKind,
213                                    SourceLocation Loc,
214                                    IndexDataConsumer &DataConsumer) {
215   // When using modules, it may happen that we find #undef of a macro that
216   // was defined in another module. In such case, MI may be nullptr, since
217   // we only look for macro definitions in the current TU. In that case,
218   // there is nothing to index.
219   if (!MI)
220     return;
221 
222   // Skip implicit visibility change.
223   if (DirectiveKind == MacroDirective::MD_Visibility)
224     return;
225 
226   auto Role = DirectiveKind == MacroDirective::MD_Define
227                   ? SymbolRole::Definition
228                   : SymbolRole::Undefinition;
229   DataConsumer.handleMacroOccurrence(II, MI, static_cast<unsigned>(Role), Loc);
230 }
231 
232 static void indexPreprocessorMacros(Preprocessor &PP,
233                                     IndexDataConsumer &DataConsumer) {
234   for (const auto &M : PP.macros()) {
235     for (auto *MD = M.second.getLatest(); MD; MD = MD->getPrevious()) {
236       indexPreprocessorMacro(M.first, MD->getMacroInfo(), MD->getKind(),
237                              MD->getLocation(), DataConsumer);
238     }
239   }
240 }
241 
242 static void indexPreprocessorModuleMacros(Preprocessor &PP,
243                                           serialization::ModuleFile &Mod,
244                                           IndexDataConsumer &DataConsumer) {
245   for (const auto &M : PP.macros()) {
246     if (M.second.getLatest() == nullptr) {
247       for (auto *MM : PP.getLeafModuleMacros(M.first)) {
248         auto *OwningMod = MM->getOwningModule();
249         if (OwningMod && OwningMod->getASTFile() == Mod.File) {
250           if (auto *MI = MM->getMacroInfo()) {
251             indexPreprocessorMacro(M.first, MI, MacroDirective::MD_Define,
252                                    MI->getDefinitionLoc(), DataConsumer);
253           }
254         }
255       }
256     }
257   }
258 }
259 
260 void index::indexASTUnit(ASTUnit &Unit, IndexDataConsumer &DataConsumer,
261                          IndexingOptions Opts) {
262   IndexingContext IndexCtx(Opts, DataConsumer);
263   IndexCtx.setASTContext(Unit.getASTContext());
264   DataConsumer.initialize(Unit.getASTContext());
265   DataConsumer.setPreprocessor(Unit.getPreprocessorPtr());
266 
267   if (Opts.IndexMacrosInPreprocessor)
268     indexPreprocessorMacros(Unit.getPreprocessor(), DataConsumer);
269   indexTranslationUnit(Unit, IndexCtx);
270   DataConsumer.finish();
271 }
272 
273 void index::indexTopLevelDecls(ASTContext &Ctx, Preprocessor &PP,
274                                ArrayRef<const Decl *> Decls,
275                                IndexDataConsumer &DataConsumer,
276                                IndexingOptions Opts) {
277   IndexingContext IndexCtx(Opts, DataConsumer);
278   IndexCtx.setASTContext(Ctx);
279 
280   DataConsumer.initialize(Ctx);
281 
282   if (Opts.IndexMacrosInPreprocessor)
283     indexPreprocessorMacros(PP, DataConsumer);
284 
285   for (const Decl *D : Decls)
286     IndexCtx.indexTopLevelDecl(D);
287   DataConsumer.finish();
288 }
289 
290 std::unique_ptr<PPCallbacks>
291 index::indexMacrosCallback(IndexDataConsumer &Consumer, IndexingOptions Opts) {
292   return std::make_unique<IndexPPCallbacks>(
293       std::make_shared<IndexingContext>(Opts, Consumer));
294 }
295 
296 void index::indexModuleFile(serialization::ModuleFile &Mod, ASTReader &Reader,
297                             IndexDataConsumer &DataConsumer,
298                             IndexingOptions Opts) {
299   ASTContext &Ctx = Reader.getContext();
300   IndexingContext IndexCtx(Opts, DataConsumer);
301   IndexCtx.setASTContext(Ctx);
302   DataConsumer.initialize(Ctx);
303 
304   if (Opts.IndexMacrosInPreprocessor) {
305     indexPreprocessorModuleMacros(Reader.getPreprocessor(), Mod, DataConsumer);
306   }
307 
308   for (const Decl *D : Reader.getModuleFileLevelDecls(Mod)) {
309     IndexCtx.indexTopLevelDecl(D);
310   }
311   DataConsumer.finish();
312 }
313