1 //===--- IncludeFixer.cpp ----------------------------------------*- C++-*-===// 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 "IncludeFixer.h" 10 #include "AST.h" 11 #include "Diagnostics.h" 12 #include "Logger.h" 13 #include "SourceCode.h" 14 #include "Trace.h" 15 #include "index/Index.h" 16 #include "index/Symbol.h" 17 #include "clang/AST/Decl.h" 18 #include "clang/AST/DeclBase.h" 19 #include "clang/AST/DeclarationName.h" 20 #include "clang/AST/NestedNameSpecifier.h" 21 #include "clang/AST/Type.h" 22 #include "clang/Basic/Diagnostic.h" 23 #include "clang/Basic/DiagnosticSema.h" 24 #include "clang/Basic/LangOptions.h" 25 #include "clang/Basic/SourceLocation.h" 26 #include "clang/Basic/SourceManager.h" 27 #include "clang/Basic/TokenKinds.h" 28 #include "clang/Lex/Lexer.h" 29 #include "clang/Sema/DeclSpec.h" 30 #include "clang/Sema/Lookup.h" 31 #include "clang/Sema/Scope.h" 32 #include "clang/Sema/Sema.h" 33 #include "clang/Sema/TypoCorrection.h" 34 #include "llvm/ADT/ArrayRef.h" 35 #include "llvm/ADT/DenseMap.h" 36 #include "llvm/ADT/None.h" 37 #include "llvm/ADT/Optional.h" 38 #include "llvm/ADT/StringExtras.h" 39 #include "llvm/ADT/StringRef.h" 40 #include "llvm/ADT/StringSet.h" 41 #include "llvm/Support/Error.h" 42 #include "llvm/Support/FormatVariadic.h" 43 #include <vector> 44 45 namespace clang { 46 namespace clangd { 47 48 namespace { 49 50 // Collects contexts visited during a Sema name lookup. 51 class VisitedContextCollector : public VisibleDeclConsumer { 52 public: 53 void EnteredContext(DeclContext *Ctx) override { Visited.push_back(Ctx); } 54 55 void FoundDecl(NamedDecl *ND, NamedDecl *Hiding, DeclContext *Ctx, 56 bool InBaseClass) override {} 57 58 std::vector<DeclContext *> takeVisitedContexts() { 59 return std::move(Visited); 60 } 61 62 private: 63 std::vector<DeclContext *> Visited; 64 }; 65 66 } // namespace 67 68 std::vector<Fix> IncludeFixer::fix(DiagnosticsEngine::Level DiagLevel, 69 const clang::Diagnostic &Info) const { 70 switch (Info.getID()) { 71 case diag::err_incomplete_type: 72 case diag::err_incomplete_member_access: 73 case diag::err_incomplete_base_class: 74 case diag::err_incomplete_nested_name_spec: 75 // Incomplete type diagnostics should have a QualType argument for the 76 // incomplete type. 77 for (unsigned Idx = 0; Idx < Info.getNumArgs(); ++Idx) { 78 if (Info.getArgKind(Idx) == DiagnosticsEngine::ak_qualtype) { 79 auto QT = QualType::getFromOpaquePtr((void *)Info.getRawArg(Idx)); 80 if (const Type *T = QT.getTypePtrOrNull()) 81 if (T->isIncompleteType()) 82 return fixIncompleteType(*T); 83 } 84 } 85 break; 86 case diag::err_unknown_typename: 87 case diag::err_unknown_typename_suggest: 88 case diag::err_typename_nested_not_found: 89 case diag::err_no_template: 90 case diag::err_no_template_suggest: 91 case diag::err_undeclared_use: 92 case diag::err_undeclared_use_suggest: 93 case diag::err_undeclared_var_use: 94 case diag::err_undeclared_var_use_suggest: 95 case diag::err_no_member: // Could be no member in namespace. 96 case diag::err_no_member_suggest: 97 if (LastUnresolvedName) { 98 // Try to fix unresolved name caused by missing declaraion. 99 // E.g. 100 // clang::SourceManager SM; 101 // ~~~~~~~~~~~~~ 102 // UnresolvedName 103 // or 104 // namespace clang { SourceManager SM; } 105 // ~~~~~~~~~~~~~ 106 // UnresolvedName 107 // We only attempt to recover a diagnostic if it has the same location as 108 // the last seen unresolved name. 109 if (DiagLevel >= DiagnosticsEngine::Error && 110 LastUnresolvedName->Loc == Info.getLocation()) 111 return fixUnresolvedName(); 112 } 113 } 114 return {}; 115 } 116 117 std::vector<Fix> IncludeFixer::fixIncompleteType(const Type &T) const { 118 // Only handle incomplete TagDecl type. 119 const TagDecl *TD = T.getAsTagDecl(); 120 if (!TD) 121 return {}; 122 std::string TypeName = printQualifiedName(*TD); 123 trace::Span Tracer("Fix include for incomplete type"); 124 SPAN_ATTACH(Tracer, "type", TypeName); 125 vlog("Trying to fix include for incomplete type {0}", TypeName); 126 127 auto ID = getSymbolID(TD); 128 if (!ID) 129 return {}; 130 llvm::Optional<const SymbolSlab *> Symbols = lookupCached(*ID); 131 if (!Symbols) 132 return {}; 133 const SymbolSlab &Syms = **Symbols; 134 std::vector<Fix> Fixes; 135 if (!Syms.empty()) { 136 auto &Matched = *Syms.begin(); 137 if (!Matched.IncludeHeaders.empty() && Matched.Definition && 138 Matched.CanonicalDeclaration.FileURI == Matched.Definition.FileURI) 139 Fixes = fixesForSymbols(Syms); 140 } 141 return Fixes; 142 } 143 144 std::vector<Fix> IncludeFixer::fixesForSymbols(const SymbolSlab &Syms) const { 145 auto Inserted = [&](const Symbol &Sym, llvm::StringRef Header) 146 -> llvm::Expected<std::pair<std::string, bool>> { 147 auto DeclaringURI = URI::parse(Sym.CanonicalDeclaration.FileURI); 148 if (!DeclaringURI) 149 return DeclaringURI.takeError(); 150 auto ResolvedDeclaring = URI::resolve(*DeclaringURI, File); 151 if (!ResolvedDeclaring) 152 return ResolvedDeclaring.takeError(); 153 auto ResolvedInserted = toHeaderFile(Header, File); 154 if (!ResolvedInserted) 155 return ResolvedInserted.takeError(); 156 auto Spelled = Inserter->calculateIncludePath(*ResolvedInserted, File); 157 if (!Spelled) 158 return llvm::createStringError(llvm::inconvertibleErrorCode(), 159 "Header not on include path"); 160 return std::make_pair( 161 std::move(*Spelled), 162 Inserter->shouldInsertInclude(*ResolvedDeclaring, *ResolvedInserted)); 163 }; 164 165 std::vector<Fix> Fixes; 166 // Deduplicate fixes by include headers. This doesn't distiguish symbols in 167 // different scopes from the same header, but this case should be rare and is 168 // thus ignored. 169 llvm::StringSet<> InsertedHeaders; 170 for (const auto &Sym : Syms) { 171 for (const auto &Inc : getRankedIncludes(Sym)) { 172 if (auto ToInclude = Inserted(Sym, Inc)) { 173 if (ToInclude->second) { 174 auto I = InsertedHeaders.try_emplace(ToInclude->first); 175 if (!I.second) 176 continue; 177 if (auto Edit = Inserter->insert(ToInclude->first)) 178 Fixes.push_back( 179 Fix{llvm::formatv("Add include {0} for symbol {1}{2}", 180 ToInclude->first, Sym.Scope, Sym.Name), 181 {std::move(*Edit)}}); 182 } 183 } else { 184 vlog("Failed to calculate include insertion for {0} into {1}: {2}", Inc, 185 File, ToInclude.takeError()); 186 } 187 } 188 } 189 return Fixes; 190 } 191 192 // Returns the identifiers qualified by an unresolved name. \p Loc is the 193 // start location of the unresolved name. For the example below, this returns 194 // "::X::Y" that is qualified by unresolved name "clangd": 195 // clang::clangd::X::Y 196 // ~ 197 llvm::Optional<std::string> qualifiedByUnresolved(const SourceManager &SM, 198 SourceLocation Loc, 199 const LangOptions &LangOpts) { 200 std::string Result; 201 202 SourceLocation NextLoc = Loc; 203 while (auto CCTok = Lexer::findNextToken(NextLoc, SM, LangOpts)) { 204 if (!CCTok->is(tok::coloncolon)) 205 break; 206 auto IDTok = Lexer::findNextToken(CCTok->getLocation(), SM, LangOpts); 207 if (!IDTok || !IDTok->is(tok::raw_identifier)) 208 break; 209 Result.append(("::" + IDTok->getRawIdentifier()).str()); 210 NextLoc = IDTok->getLocation(); 211 } 212 if (Result.empty()) 213 return llvm::None; 214 return Result; 215 } 216 217 // An unresolved name and its scope information that can be extracted cheaply. 218 struct CheapUnresolvedName { 219 std::string Name; 220 // This is the part of what was typed that was resolved, and it's in its 221 // resolved form not its typed form (think `namespace clang { clangd::x }` --> 222 // `clang::clangd::`). 223 llvm::Optional<std::string> ResolvedScope; 224 225 // Unresolved part of the scope. When the unresolved name is a specifier, we 226 // use the name that comes after it as the alternative name to resolve and use 227 // the specifier as the extra scope in the accessible scopes. 228 llvm::Optional<std::string> UnresolvedScope; 229 }; 230 231 // Extracts unresolved name and scope information around \p Unresolved. 232 // FIXME: try to merge this with the scope-wrangling code in CodeComplete. 233 llvm::Optional<CheapUnresolvedName> extractUnresolvedNameCheaply( 234 const SourceManager &SM, const DeclarationNameInfo &Unresolved, 235 CXXScopeSpec *SS, const LangOptions &LangOpts, bool UnresolvedIsSpecifier) { 236 bool Invalid = false; 237 llvm::StringRef Code = SM.getBufferData( 238 SM.getDecomposedLoc(Unresolved.getBeginLoc()).first, &Invalid); 239 if (Invalid) 240 return llvm::None; 241 CheapUnresolvedName Result; 242 Result.Name = Unresolved.getAsString(); 243 if (SS && SS->isNotEmpty()) { // "::" or "ns::" 244 if (auto *Nested = SS->getScopeRep()) { 245 if (Nested->getKind() == NestedNameSpecifier::Global) 246 Result.ResolvedScope = ""; 247 else if (const auto *NS = Nested->getAsNamespace()) { 248 auto SpecifiedNS = printNamespaceScope(*NS); 249 250 // Check the specifier spelled in the source. 251 // If the resolved scope doesn't end with the spelled scope. The 252 // resolved scope can come from a sema typo correction. For example, 253 // sema assumes that "clangd::" is a typo of "clang::" and uses 254 // "clang::" as the specified scope in: 255 // namespace clang { clangd::X; } 256 // In this case, we use the "typo" specifier as extra scope instead 257 // of using the scope assumed by sema. 258 auto B = SM.getFileOffset(SS->getBeginLoc()); 259 auto E = SM.getFileOffset(SS->getEndLoc()); 260 std::string Spelling = (Code.substr(B, E - B) + "::").str(); 261 if (llvm::StringRef(SpecifiedNS).endswith(Spelling)) 262 Result.ResolvedScope = SpecifiedNS; 263 else 264 Result.UnresolvedScope = Spelling; 265 } else if (const auto *ANS = Nested->getAsNamespaceAlias()) { 266 Result.ResolvedScope = printNamespaceScope(*ANS->getNamespace()); 267 } else { 268 // We don't fix symbols in scopes that are not top-level e.g. class 269 // members, as we don't collect includes for them. 270 return llvm::None; 271 } 272 } 273 } 274 275 if (UnresolvedIsSpecifier) { 276 // If the unresolved name is a specifier e.g. 277 // clang::clangd::X 278 // ~~~~~~ 279 // We try to resolve clang::clangd::X instead of clang::clangd. 280 // FIXME: We won't be able to fix include if the specifier is what we 281 // should resolve (e.g. it's a class scope specifier). Collecting include 282 // headers for nested types could make this work. 283 284 // Not using the end location as it doesn't always point to the end of 285 // identifier. 286 if (auto QualifiedByUnresolved = 287 qualifiedByUnresolved(SM, Unresolved.getBeginLoc(), LangOpts)) { 288 auto Split = splitQualifiedName(*QualifiedByUnresolved); 289 if (!Result.UnresolvedScope) 290 Result.UnresolvedScope.emplace(); 291 // If UnresolvedSpecifiedScope is already set, we simply append the 292 // extra scope. Suppose the unresolved name is "index" in the following 293 // example: 294 // namespace clang { clangd::index::X; } 295 // ~~~~~~ ~~~~~ 296 // "clangd::" is assumed to be clang:: by Sema, and we would have used 297 // it as extra scope. With "index" being a specifier, we append "index::" 298 // to the extra scope. 299 Result.UnresolvedScope->append((Result.Name + Split.first).str()); 300 Result.Name = Split.second; 301 } 302 } 303 return Result; 304 } 305 306 /// Returns all namespace scopes that the unqualified lookup would visit. 307 std::vector<std::string> 308 collectAccessibleScopes(Sema &Sem, const DeclarationNameInfo &Typo, Scope *S, 309 Sema::LookupNameKind LookupKind) { 310 std::vector<std::string> Scopes; 311 VisitedContextCollector Collector; 312 Sem.LookupVisibleDecls(S, LookupKind, Collector, 313 /*IncludeGlobalScope=*/false, 314 /*LoadExternal=*/false); 315 316 Scopes.push_back(""); 317 for (const auto *Ctx : Collector.takeVisitedContexts()) { 318 if (isa<NamespaceDecl>(Ctx)) 319 Scopes.push_back(printNamespaceScope(*Ctx)); 320 } 321 return Scopes; 322 } 323 324 class IncludeFixer::UnresolvedNameRecorder : public ExternalSemaSource { 325 public: 326 UnresolvedNameRecorder(llvm::Optional<UnresolvedName> &LastUnresolvedName) 327 : LastUnresolvedName(LastUnresolvedName) {} 328 329 void InitializeSema(Sema &S) override { this->SemaPtr = &S; } 330 331 // Captures the latest typo and treat it as an unresolved name that can 332 // potentially be fixed by adding #includes. 333 TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo, int LookupKind, 334 Scope *S, CXXScopeSpec *SS, 335 CorrectionCandidateCallback &CCC, 336 DeclContext *MemberContext, bool EnteringContext, 337 const ObjCObjectPointerType *OPT) override { 338 assert(SemaPtr && "Sema must have been set."); 339 if (SemaPtr->isSFINAEContext()) 340 return TypoCorrection(); 341 if (!isInsideMainFile(Typo.getLoc(), SemaPtr->SourceMgr)) 342 return clang::TypoCorrection(); 343 344 auto Extracted = extractUnresolvedNameCheaply( 345 SemaPtr->SourceMgr, Typo, SS, SemaPtr->LangOpts, 346 static_cast<Sema::LookupNameKind>(LookupKind) == 347 Sema::LookupNameKind::LookupNestedNameSpecifierName); 348 if (!Extracted) 349 return TypoCorrection(); 350 351 UnresolvedName Unresolved; 352 Unresolved.Name = Extracted->Name; 353 Unresolved.Loc = Typo.getBeginLoc(); 354 if (!Extracted->ResolvedScope && !S) // Give up if no scope available. 355 return TypoCorrection(); 356 357 if (Extracted->ResolvedScope) 358 Unresolved.Scopes.push_back(*Extracted->ResolvedScope); 359 else // no qualifier or qualifier is unresolved. 360 Unresolved.Scopes = collectAccessibleScopes( 361 *SemaPtr, Typo, S, static_cast<Sema::LookupNameKind>(LookupKind)); 362 363 if (Extracted->UnresolvedScope) { 364 for (std::string &Scope : Unresolved.Scopes) 365 Scope += *Extracted->UnresolvedScope; 366 } 367 368 LastUnresolvedName = std::move(Unresolved); 369 370 // Never return a valid correction to try to recover. Our suggested fixes 371 // always require a rebuild. 372 return TypoCorrection(); 373 } 374 375 private: 376 Sema *SemaPtr = nullptr; 377 378 llvm::Optional<UnresolvedName> &LastUnresolvedName; 379 }; 380 381 llvm::IntrusiveRefCntPtr<ExternalSemaSource> 382 IncludeFixer::unresolvedNameRecorder() { 383 return new UnresolvedNameRecorder(LastUnresolvedName); 384 } 385 386 std::vector<Fix> IncludeFixer::fixUnresolvedName() const { 387 assert(LastUnresolvedName.hasValue()); 388 auto &Unresolved = *LastUnresolvedName; 389 vlog("Trying to fix unresolved name \"{0}\" in scopes: [{1}]", 390 Unresolved.Name, llvm::join(Unresolved.Scopes, ", ")); 391 392 FuzzyFindRequest Req; 393 Req.AnyScope = false; 394 Req.Query = Unresolved.Name; 395 Req.Scopes = Unresolved.Scopes; 396 Req.RestrictForCodeCompletion = true; 397 Req.Limit = 100; 398 399 if (llvm::Optional<const SymbolSlab *> Syms = fuzzyFindCached(Req)) 400 return fixesForSymbols(**Syms); 401 402 return {}; 403 } 404 405 llvm::Optional<const SymbolSlab *> 406 IncludeFixer::fuzzyFindCached(const FuzzyFindRequest &Req) const { 407 auto ReqStr = llvm::formatv("{0}", toJSON(Req)).str(); 408 auto I = FuzzyFindCache.find(ReqStr); 409 if (I != FuzzyFindCache.end()) 410 return &I->second; 411 412 if (IndexRequestCount >= IndexRequestLimit) 413 return llvm::None; 414 IndexRequestCount++; 415 416 SymbolSlab::Builder Matches; 417 Index.fuzzyFind(Req, [&](const Symbol &Sym) { 418 if (Sym.Name != Req.Query) 419 return; 420 if (!Sym.IncludeHeaders.empty()) 421 Matches.insert(Sym); 422 }); 423 auto Syms = std::move(Matches).build(); 424 auto E = FuzzyFindCache.try_emplace(ReqStr, std::move(Syms)); 425 return &E.first->second; 426 } 427 428 llvm::Optional<const SymbolSlab *> 429 IncludeFixer::lookupCached(const SymbolID &ID) const { 430 LookupRequest Req; 431 Req.IDs.insert(ID); 432 433 auto I = LookupCache.find(ID); 434 if (I != LookupCache.end()) 435 return &I->second; 436 437 if (IndexRequestCount >= IndexRequestLimit) 438 return llvm::None; 439 IndexRequestCount++; 440 441 // FIXME: consider batching the requests for all diagnostics. 442 SymbolSlab::Builder Matches; 443 Index.lookup(Req, [&](const Symbol &Sym) { Matches.insert(Sym); }); 444 auto Syms = std::move(Matches).build(); 445 446 std::vector<Fix> Fixes; 447 if (!Syms.empty()) { 448 auto &Matched = *Syms.begin(); 449 if (!Matched.IncludeHeaders.empty() && Matched.Definition && 450 Matched.CanonicalDeclaration.FileURI == Matched.Definition.FileURI) 451 Fixes = fixesForSymbols(Syms); 452 } 453 auto E = LookupCache.try_emplace(ID, std::move(Syms)); 454 return &E.first->second; 455 } 456 457 } // namespace clangd 458 } // namespace clang 459