clang-tools-extra/clang-include-fixer/IncludeFixer.cpp

   1 //===-- IncludeFixer.cpp - Include inserter based on sema callbacks -------===//
   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 "clang/Format/Format.h"
  11 #include "clang/Frontend/CompilerInstance.h"
  12 #include "clang/Lex/HeaderSearch.h"
  13 #include "clang/Lex/Preprocessor.h"
  14 #include "clang/Parse/ParseAST.h"
  15 #include "clang/Sema/Sema.h"
  16 #include "llvm/Support/Debug.h"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 #define DEBUG_TYPE "clang-include-fixer"
  20
  21 using namespace clang;
  22
  23 namespace clang {
  24 namespace include_fixer {
  25 namespace {
  26 /// Manages the parse, gathers include suggestions.
  27 class Action : public clang::ASTFrontendAction {
  28 public:
  29   explicit Action(SymbolIndexManager &SymbolIndexMgr, bool MinimizeIncludePaths)
  30       : SemaSource(new IncludeFixerSemaSource(SymbolIndexMgr,
  31                                               MinimizeIncludePaths,
  32                                               /*GenerateDiagnostics=*/false)) {}
  33
  34   std::unique_ptr<clang::ASTConsumer>
  35   CreateASTConsumer(clang::CompilerInstance &Compiler,
  36                     StringRef InFile) override {
  37     SemaSource->setFilePath(InFile);
  38     return std::make_unique<clang::ASTConsumer>();
  39   }
  40
  41   void ExecuteAction() override {
  42     clang::CompilerInstance *Compiler = &getCompilerInstance();
  43     assert(!Compiler->hasSema() && "CI already has Sema");
  44
  45     // Set up our hooks into sema and parse the AST.
  46     if (hasCodeCompletionSupport() &&
  47         !Compiler->getFrontendOpts().CodeCompletionAt.FileName.empty())
  48       Compiler->createCodeCompletionConsumer();
  49
  50     clang::CodeCompleteConsumer *CompletionConsumer = nullptr;
  51     if (Compiler->hasCodeCompletionConsumer())
  52       CompletionConsumer = &Compiler->getCodeCompletionConsumer();
  53
  54     Compiler->createSema(getTranslationUnitKind(), CompletionConsumer);
  55     SemaSource->setCompilerInstance(Compiler);
  56     Compiler->getSema().addExternalSource(SemaSource.get());
  57
  58     clang::ParseAST(Compiler->getSema(), Compiler->getFrontendOpts().ShowStats,
  59                     Compiler->getFrontendOpts().SkipFunctionBodies);
  60   }
  61
  62   IncludeFixerContext
  63   getIncludeFixerContext(const clang::SourceManager &SourceManager,
  64                          clang::HeaderSearch &HeaderSearch) const {
  65     return SemaSource->getIncludeFixerContext(SourceManager, HeaderSearch,
  66                                               SemaSource->getMatchedSymbols());
  67   }
  68
  69 private:
  70   IntrusiveRefCntPtr<IncludeFixerSemaSource> SemaSource;
  71 };
  72
  73 } // namespace
  74
  75 IncludeFixerActionFactory::IncludeFixerActionFactory(
  76     SymbolIndexManager &SymbolIndexMgr,
  77     std::vector<IncludeFixerContext> &Contexts, StringRef StyleName,
  78     bool MinimizeIncludePaths)
  79     : SymbolIndexMgr(SymbolIndexMgr), Contexts(Contexts),
  80       MinimizeIncludePaths(MinimizeIncludePaths) {}
  81
  82 IncludeFixerActionFactory::~IncludeFixerActionFactory() = default;
  83
  84 bool IncludeFixerActionFactory::runInvocation(
  85     std::shared_ptr<clang::CompilerInvocation> Invocation,
  86     clang::FileManager *Files,
  87     std::shared_ptr<clang::PCHContainerOperations> PCHContainerOps,
  88     clang::DiagnosticConsumer *Diagnostics) {
  89   assert(Invocation->getFrontendOpts().Inputs.size() == 1);
  90
  91   // Set up Clang.
  92   clang::CompilerInstance Compiler(PCHContainerOps);
  93   Compiler.setInvocation(std::move(Invocation));
  94   Compiler.setFileManager(Files);
  95
  96   // Create the compiler's actual diagnostics engine. We want to drop all
  97   // diagnostics here.
  98   Compiler.createDiagnostics(new clang::IgnoringDiagConsumer,
  99                              /*ShouldOwnClient=*/true);
 100   Compiler.createSourceManager(*Files);
 101
 102   // We abort on fatal errors so don't let a large number of errors become
 103   // fatal. A missing #include can cause thousands of errors.
 104   Compiler.getDiagnostics().setErrorLimit(0);
 105
 106   // Run the parser, gather missing includes.
 107   auto ScopedToolAction =
 108       std::make_unique<Action>(SymbolIndexMgr, MinimizeIncludePaths);
 109   Compiler.ExecuteAction(*ScopedToolAction);
 110
 111   Contexts.push_back(ScopedToolAction->getIncludeFixerContext(
 112       Compiler.getSourceManager(),
 113       Compiler.getPreprocessor().getHeaderSearchInfo()));
 114
 115   // Technically this should only return true if we're sure that we have a
 116   // parseable file. We don't know that though. Only inform users of fatal
 117   // errors.
 118   return !Compiler.getDiagnostics().hasFatalErrorOccurred();
 119 }
 120
 121 static bool addDiagnosticsForContext(TypoCorrection &Correction,
 122                                      const IncludeFixerContext &Context,
 123                                      StringRef Code, SourceLocation StartOfFile,
 124                                      ASTContext &Ctx) {
 125   auto Reps = createIncludeFixerReplacements(
 126       Code, Context, format::getLLVMStyle(), /*AddQualifiers=*/false);
 127   if (!Reps || Reps->size() != 1)
 128     return false;
 129
 130   unsigned DiagID = Ctx.getDiagnostics().getCustomDiagID(
 131       DiagnosticsEngine::Note, "Add '#include %0' to provide the missing "
 132                                "declaration [clang-include-fixer]");
 133
 134   // FIXME: Currently we only generate a diagnostic for the first header. Give
 135   // the user choices.
 136   const tooling::Replacement &Placed = *Reps->begin();
 137
 138   auto Begin = StartOfFile.getLocWithOffset(Placed.getOffset());
 139   auto End = Begin.getLocWithOffset(std::max(0, (int)Placed.getLength() - 1));
 140   PartialDiagnostic PD(DiagID, Ctx.getDiagAllocator());
 141   PD << Context.getHeaderInfos().front().Header
 142      << FixItHint::CreateReplacement(CharSourceRange::getCharRange(Begin, End),
 143                                      Placed.getReplacementText());
 144   Correction.addExtraDiagnostic(std::move(PD));
 145   return true;
 146 }
 147
 148 /// Callback for incomplete types. If we encounter a forward declaration we
 149 /// have the fully qualified name ready. Just query that.
 150 bool IncludeFixerSemaSource::MaybeDiagnoseMissingCompleteType(
 151     clang::SourceLocation Loc, clang::QualType T) {
 152   // Ignore spurious callbacks from SFINAE contexts.
 153   if (CI->getSema().isSFINAEContext())
 154     return false;
 155
 156   clang::ASTContext &context = CI->getASTContext();
 157   std::string QueryString = QualType(T->getUnqualifiedDesugaredType(), 0)
 158                                 .getAsString(context.getPrintingPolicy());
 159   LLVM_DEBUG(llvm::dbgs() << "Query missing complete type '" << QueryString
 160                           << "'");
 161   // Pass an empty range here since we don't add qualifier in this case.
 162   std::vector<find_all_symbols::SymbolInfo> MatchedSymbols =
 163       query(QueryString, "", tooling::Range());
 164
 165   if (!MatchedSymbols.empty() && GenerateDiagnostics) {
 166     TypoCorrection Correction;
 167     FileID FID = CI->getSourceManager().getFileID(Loc);
 168     StringRef Code = CI->getSourceManager().getBufferData(FID);
 169     SourceLocation StartOfFile =
 170         CI->getSourceManager().getLocForStartOfFile(FID);
 171     addDiagnosticsForContext(
 172         Correction,
 173         getIncludeFixerContext(CI->getSourceManager(),
 174                                CI->getPreprocessor().getHeaderSearchInfo(),
 175                                MatchedSymbols),
 176         Code, StartOfFile, CI->getASTContext());
 177     for (const PartialDiagnostic &PD : Correction.getExtraDiagnostics())
 178       CI->getSema().Diag(Loc, PD);
 179   }
 180   return true;
 181 }
 182
 183 /// Callback for unknown identifiers. Try to piece together as much
 184 /// qualification as we can get and do a query.
 185 clang::TypoCorrection IncludeFixerSemaSource::CorrectTypo(
 186     const DeclarationNameInfo &Typo, int LookupKind, Scope *S, CXXScopeSpec *SS,
 187     CorrectionCandidateCallback &CCC, DeclContext *MemberContext,
 188     bool EnteringContext, const ObjCObjectPointerType *OPT) {
 189   // Ignore spurious callbacks from SFINAE contexts.
 190   if (CI->getSema().isSFINAEContext())
 191     return clang::TypoCorrection();
 192
 193   // We currently ignore the unidentified symbol which is not from the
 194   // main file.
 195   //
 196   // However, this is not always true due to templates in a non-self contained
 197   // header, consider the case:
 198   //
 199   //   // header.h
 200   //   template <typename T>
 201   //   class Foo {
 202   //     T t;
 203   //   };
 204   //
 205   //   // test.cc
 206   //   // We need to add <bar.h> in test.cc instead of header.h.
 207   //   class Bar;
 208   //   Foo<Bar> foo;
 209   //
 210   // FIXME: Add the missing header to the header file where the symbol comes
 211   // from.
 212   if (!CI->getSourceManager().isWrittenInMainFile(Typo.getLoc()))
 213     return clang::TypoCorrection();
 214
 215   std::string TypoScopeString;
 216   if (S) {
 217     // FIXME: Currently we only use namespace contexts. Use other context
 218     // types for query.
 219     for (const auto *Context = S->getEntity(); Context;
 220          Context = Context->getParent()) {
 221       if (const auto *ND = dyn_cast<NamespaceDecl>(Context)) {
 222         if (!ND->getName().empty())
 223           TypoScopeString = ND->getNameAsString() + "::" + TypoScopeString;
 224       }
 225     }
 226   }
 227
 228   auto ExtendNestedNameSpecifier = [this](CharSourceRange Range) {
 229     StringRef Source =
 230         Lexer::getSourceText(Range, CI->getSourceManager(), CI->getLangOpts());
 231
 232     // Skip forward until we find a character that's neither identifier nor
 233     // colon. This is a bit of a hack around the fact that we will only get a
 234     // single callback for a long nested name if a part of the beginning is
 235     // unknown. For example:
 236     //
 237     // llvm::sys::path::parent_path(...)
 238     // ^~~~  ^~~
 239     //    known
 240     //            ^~~~
 241     //      unknown, last callback
 242     //                  ^~~~~~~~~~~
 243     //                  no callback
 244     //
 245     // With the extension we get the full nested name specifier including
 246     // parent_path.
 247     // FIXME: Don't rely on source text.
 248     const char *End = Source.end();
 249     while (isAsciiIdentifierContinue(*End) || *End == ':')
 250       ++End;
 251
 252     return std::string(Source.begin(), End);
 253   };
 254
 255   /// If we have a scope specification, use that to get more precise results.
 256   std::string QueryString;
 257   tooling::Range SymbolRange;
 258   const auto &SM = CI->getSourceManager();
 259   auto CreateToolingRange = [&QueryString, &SM](SourceLocation BeginLoc) {
 260     return tooling::Range(SM.getDecomposedLoc(BeginLoc).second,
 261                           QueryString.size());
 262   };
 263   if (SS && SS->getRange().isValid()) {
 264     auto Range = CharSourceRange::getTokenRange(SS->getRange().getBegin(),
 265                                                 Typo.getLoc());
 266
 267     QueryString = ExtendNestedNameSpecifier(Range);
 268     SymbolRange = CreateToolingRange(Range.getBegin());
 269   } else if (Typo.getName().isIdentifier() && !Typo.getLoc().isMacroID()) {
 270     auto Range =
 271         CharSourceRange::getTokenRange(Typo.getBeginLoc(), Typo.getEndLoc());
 272
 273     QueryString = ExtendNestedNameSpecifier(Range);
 274     SymbolRange = CreateToolingRange(Range.getBegin());
 275   } else {
 276     QueryString = Typo.getAsString();
 277     SymbolRange = CreateToolingRange(Typo.getLoc());
 278   }
 279
 280   LLVM_DEBUG(llvm::dbgs() << "TypoScopeQualifiers: " << TypoScopeString
 281                           << "\n");
 282   std::vector<find_all_symbols::SymbolInfo> MatchedSymbols =
 283       query(QueryString, TypoScopeString, SymbolRange);
 284
 285   if (!MatchedSymbols.empty() && GenerateDiagnostics) {
 286     TypoCorrection Correction(Typo.getName());
 287     Correction.setCorrectionRange(SS, Typo);
 288     FileID FID = SM.getFileID(Typo.getLoc());
 289     StringRef Code = SM.getBufferData(FID);
 290     SourceLocation StartOfFile = SM.getLocForStartOfFile(FID);
 291     if (addDiagnosticsForContext(
 292             Correction, getIncludeFixerContext(
 293                             SM, CI->getPreprocessor().getHeaderSearchInfo(),
 294                             MatchedSymbols),
 295             Code, StartOfFile, CI->getASTContext()))
 296       return Correction;
 297   }
 298   return TypoCorrection();
 299 }
 300
 301 /// Get the minimal include for a given path.
 302 std::string IncludeFixerSemaSource::minimizeInclude(
 303     StringRef Include, const clang::SourceManager &SourceManager,
 304     clang::HeaderSearch &HeaderSearch) const {
 305   if (!MinimizeIncludePaths)
 306     return std::string(Include);
 307
 308   // Get the FileEntry for the include.
 309   StringRef StrippedInclude = Include.trim("\"<>");
 310   auto Entry =
 311       SourceManager.getFileManager().getOptionalFileRef(StrippedInclude);
 312
 313   // If the file doesn't exist return the path from the database.
 314   // FIXME: This should never happen.
 315   if (!Entry)
 316     return std::string(Include);
 317
 318   bool IsAngled = false;
 319   std::string Suggestion =
 320       HeaderSearch.suggestPathToFileForDiagnostics(*Entry, "", &IsAngled);
 321
 322   return IsAngled ? '<' + Suggestion + '>' : '"' + Suggestion + '"';
 323 }
 324
 325 /// Get the include fixer context for the queried symbol.
 326 IncludeFixerContext IncludeFixerSemaSource::getIncludeFixerContext(
 327     const clang::SourceManager &SourceManager,
 328     clang::HeaderSearch &HeaderSearch,
 329     ArrayRef<find_all_symbols::SymbolInfo> MatchedSymbols) const {
 330   std::vector<find_all_symbols::SymbolInfo> SymbolCandidates;
 331   for (const auto &Symbol : MatchedSymbols) {
 332     std::string FilePath = Symbol.getFilePath().str();
 333     std::string MinimizedFilePath = minimizeInclude(
 334         ((FilePath[0] == '"' || FilePath[0] == '<') ? FilePath
 335                                                     : "\"" + FilePath + "\""),
 336         SourceManager, HeaderSearch);
 337     SymbolCandidates.emplace_back(Symbol.getName(), Symbol.getSymbolKind(),
 338                                   MinimizedFilePath, Symbol.getContexts());
 339   }
 340   return IncludeFixerContext(FilePath, QuerySymbolInfos, SymbolCandidates);
 341 }
 342
 343 std::vector<find_all_symbols::SymbolInfo>
 344 IncludeFixerSemaSource::query(StringRef Query, StringRef ScopedQualifiers,
 345                               tooling::Range Range) {
 346   assert(!Query.empty() && "Empty query!");
 347
 348   // Save all instances of an unidentified symbol.
 349   //
 350   // We use conservative behavior for detecting the same unidentified symbol
 351   // here. The symbols which have the same ScopedQualifier and RawIdentifier
 352   // are considered equal. So that clang-include-fixer avoids false positives,
 353   // and always adds missing qualifiers to correct symbols.
 354   if (!GenerateDiagnostics && !QuerySymbolInfos.empty()) {
 355     if (ScopedQualifiers == QuerySymbolInfos.front().ScopedQualifiers &&
 356         Query == QuerySymbolInfos.front().RawIdentifier) {
 357       QuerySymbolInfos.push_back(
 358           {Query.str(), std::string(ScopedQualifiers), Range});
 359     }
 360     return {};
 361   }
 362
 363   LLVM_DEBUG(llvm::dbgs() << "Looking up '" << Query << "' at ");
 364   LLVM_DEBUG(CI->getSourceManager()
 365                  .getLocForStartOfFile(CI->getSourceManager().getMainFileID())
 366                  .getLocWithOffset(Range.getOffset())
 367                  .print(llvm::dbgs(), CI->getSourceManager()));
 368   LLVM_DEBUG(llvm::dbgs() << " ...");
 369   llvm::StringRef FileName = CI->getSourceManager().getFilename(
 370       CI->getSourceManager().getLocForStartOfFile(
 371           CI->getSourceManager().getMainFileID()));
 372
 373   QuerySymbolInfos.push_back(
 374       {Query.str(), std::string(ScopedQualifiers), Range});
 375
 376   // Query the symbol based on C++ name Lookup rules.
 377   // Firstly, lookup the identifier with scoped namespace contexts;
 378   // If that fails, falls back to look up the identifier directly.
 379   //
 380   // For example:
 381   //
 382   // namespace a {
 383   // b::foo f;
 384   // }
 385   //
 386   // 1. lookup a::b::foo.
 387   // 2. lookup b::foo.
 388   std::string QueryString = ScopedQualifiers.str() + Query.str();
 389   // It's unsafe to do nested search for the identifier with scoped namespace
 390   // context, it might treat the identifier as a nested class of the scoped
 391   // namespace.
 392   std::vector<find_all_symbols::SymbolInfo> MatchedSymbols =
 393       SymbolIndexMgr.search(QueryString, /*IsNestedSearch=*/false, FileName);
 394   if (MatchedSymbols.empty())
 395     MatchedSymbols =
 396         SymbolIndexMgr.search(Query, /*IsNestedSearch=*/true, FileName);
 397   LLVM_DEBUG(llvm::dbgs() << "Having found " << MatchedSymbols.size()
 398                           << " symbols\n");
 399   // We store a copy of MatchedSymbols in a place where it's globally reachable.
 400   // This is used by the standalone version of the tool.
 401   this->MatchedSymbols = MatchedSymbols;
 402   return MatchedSymbols;
 403 }
 404
 405 llvm::Expected<tooling::Replacements> createIncludeFixerReplacements(
 406     StringRef Code, const IncludeFixerContext &Context,
 407     const clang::format::FormatStyle &Style, bool AddQualifiers) {
 408   if (Context.getHeaderInfos().empty())
 409     return tooling::Replacements();
 410   StringRef FilePath = Context.getFilePath();
 411   std::string IncludeName =
 412       "#include " + Context.getHeaderInfos().front().Header + "\n";
 413   // Create replacements for the new header.
 414   clang::tooling::Replacements Insertions;
 415   auto Err =
 416       Insertions.add(tooling::Replacement(FilePath, UINT_MAX, 0, IncludeName));
 417   if (Err)
 418     return std::move(Err);
 419
 420   auto CleanReplaces = cleanupAroundReplacements(Code, Insertions, Style);
 421   if (!CleanReplaces)
 422     return CleanReplaces;
 423
 424   auto Replaces = std::move(*CleanReplaces);
 425   if (AddQualifiers) {
 426     for (const auto &Info : Context.getQuerySymbolInfos()) {
 427       // Ignore the empty range.
 428       if (Info.Range.getLength() > 0) {
 429         auto R = tooling::Replacement(
 430             {FilePath, Info.Range.getOffset(), Info.Range.getLength(),
 431              Context.getHeaderInfos().front().QualifiedName});
 432         auto Err = Replaces.add(R);
 433         if (Err) {
 434           llvm::consumeError(std::move(Err));
 435           R = tooling::Replacement(
 436               R.getFilePath(), Replaces.getShiftedCodePosition(R.getOffset()),
 437               R.getLength(), R.getReplacementText());
 438           Replaces = Replaces.merge(tooling::Replacements(R));
 439         }
 440       }
 441     }
 442   }
 443   return formatReplacements(Code, Replaces, Style);
 444 }
 445
 446 } // namespace include_fixer
 447 } // namespace clang