clang-tools-extra/clangd/ParsedAST.h

   1 //===--- ParsedAST.h - Building translation units ----------------*- 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 // This file exposes building a file as if it were open in clangd, and defines
  10 // the ParsedAST structure that holds the results.
  11 //
  12 // This is similar to a clang -fsyntax-only run that produces a clang AST, but
  13 // we have several customizations:
  14 //  - preamble handling
  15 //  - capturing diagnostics for later access
  16 //  - running clang-tidy checks
  17 //
  18 //===----------------------------------------------------------------------===//
  19
  20 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_PARSEDAST_H
  21 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_PARSEDAST_H
  22
  23 #include "CollectMacros.h"
  24 #include "Compiler.h"
  25 #include "Diagnostics.h"
  26 #include "Headers.h"
  27 #include "Preamble.h"
  28 #include "clang-include-cleaner/Record.h"
  29 #include "support/Path.h"
  30 #include "clang/Frontend/FrontendAction.h"
  31 #include "clang/Lex/Preprocessor.h"
  32 #include "clang/Tooling/Syntax/Tokens.h"
  33 #include "llvm/ADT/ArrayRef.h"
  34 #include "llvm/ADT/StringRef.h"
  35 #include <memory>
  36 #include <optional>
  37 #include <string>
  38 #include <vector>
  39
  40 namespace clang {
  41 class HeuristicResolver;
  42 class Sema;
  43 namespace clangd {
  44
  45 /// Stores and provides access to parsed AST.
  46 class ParsedAST {
  47 public:
  48   /// Attempts to run Clang and store the parsed AST.
  49   /// If \p Preamble is non-null it is reused during parsing.
  50   /// This function does not check if preamble is valid to reuse.
  51   static std::optional<ParsedAST>
  52   build(llvm::StringRef Filename, const ParseInputs &Inputs,
  53         std::unique_ptr<clang::CompilerInvocation> CI,
  54         llvm::ArrayRef<Diag> CompilerInvocationDiags,
  55         std::shared_ptr<const PreambleData> Preamble);
  56
  57   ParsedAST(ParsedAST &&Other);
  58   ParsedAST &operator=(ParsedAST &&Other);
  59
  60   ~ParsedAST();
  61
  62   ParsedAST(const ParsedAST &Other) = delete;
  63   ParsedAST &operator=(const ParsedAST &Other) = delete;
  64
  65   /// Note that the returned ast will not contain decls from the preamble that
  66   /// were not deserialized during parsing. Clients should expect only decls
  67   /// from the main file to be in the AST.
  68   ASTContext &getASTContext();
  69   const ASTContext &getASTContext() const;
  70
  71   Sema &getSema();
  72
  73   Preprocessor &getPreprocessor();
  74   std::shared_ptr<Preprocessor> getPreprocessorPtr();
  75   const Preprocessor &getPreprocessor() const;
  76
  77   SourceManager &getSourceManager() {
  78     return getASTContext().getSourceManager();
  79   }
  80   const SourceManager &getSourceManager() const {
  81     return getASTContext().getSourceManager();
  82   }
  83
  84   const LangOptions &getLangOpts() const {
  85     return getASTContext().getLangOpts();
  86   }
  87
  88   /// This function returns top-level decls present in the main file of the AST.
  89   /// The result does not include the decls that come from the preamble.
  90   /// (These should be const, but RecursiveASTVisitor requires Decl*).
  91   ArrayRef<Decl *> getLocalTopLevelDecls();
  92   ArrayRef<const Decl *> getLocalTopLevelDecls() const;
  93
  94   llvm::ArrayRef<Diag> getDiagnostics() const;
  95
  96   /// Returns the estimated size of the AST and the accessory structures, in
  97   /// bytes. Does not include the size of the preamble.
  98   std::size_t getUsedBytes() const;
  99   const IncludeStructure &getIncludeStructure() const;
 100
 101   /// Gets all macro references (definition, expansions) present in the main
 102   /// file, including those in the preamble region.
 103   const MainFileMacros &getMacros() const;
 104   /// Gets all pragma marks in the main file.
 105   const std::vector<PragmaMark> &getMarks() const;
 106   /// Tokens recorded while parsing the main file.
 107   /// (!) does not have tokens from the preamble.
 108   const syntax::TokenBuffer &getTokens() const { return Tokens; }
 109   /// Returns the PramaIncludes for preamble + main file includes.
 110   const include_cleaner::PragmaIncludes &getPragmaIncludes() const;
 111
 112   /// Returns the version of the ParseInputs this AST was built from.
 113   llvm::StringRef version() const { return Version; }
 114
 115   /// Returns the path passed by the caller when building this AST.
 116   PathRef tuPath() const { return TUPath; }
 117
 118   /// Returns the version of the ParseInputs used to build Preamble part of this
 119   /// AST. Might be std::nullopt if no Preamble is used.
 120   std::optional<llvm::StringRef> preambleVersion() const;
 121
 122   const HeuristicResolver *getHeuristicResolver() const {
 123     return Resolver.get();
 124   }
 125
 126 private:
 127   ParsedAST(PathRef TUPath, llvm::StringRef Version,
 128             std::shared_ptr<const PreambleData> Preamble,
 129             std::unique_ptr<CompilerInstance> Clang,
 130             std::unique_ptr<FrontendAction> Action, syntax::TokenBuffer Tokens,
 131             MainFileMacros Macros, std::vector<PragmaMark> Marks,
 132             std::vector<Decl *> LocalTopLevelDecls, std::vector<Diag> Diags,
 133             IncludeStructure Includes, include_cleaner::PragmaIncludes PI);
 134   Path TUPath;
 135   std::string Version;
 136   // In-memory preambles must outlive the AST, it is important that this member
 137   // goes before Clang and Action.
 138   std::shared_ptr<const PreambleData> Preamble;
 139   // We store an "incomplete" FrontendAction (i.e. no EndSourceFile was called
 140   // on it) and CompilerInstance used to run it. That way we don't have to do
 141   // complex memory management of all Clang structures on our own. (They are
 142   // stored in CompilerInstance and cleaned up by
 143   // FrontendAction.EndSourceFile).
 144   std::unique_ptr<CompilerInstance> Clang;
 145   std::unique_ptr<FrontendAction> Action;
 146   /// Tokens recorded after the preamble finished.
 147   ///   - Includes all spelled tokens for the main file.
 148   ///   - Includes expanded tokens produced **after** preamble.
 149   ///   - Does not have spelled or expanded tokens for files from preamble.
 150   syntax::TokenBuffer Tokens;
 151
 152   /// All macro definitions and expansions in the main file.
 153   MainFileMacros Macros;
 154   // Pragma marks in the main file.
 155   std::vector<PragmaMark> Marks;
 156   // Diags emitted while parsing this AST (including preamble and compiler
 157   // invocation).
 158   std::vector<Diag> Diags;
 159   // Top-level decls inside the current file. Not that this does not include
 160   // top-level decls from the preamble.
 161   std::vector<Decl *> LocalTopLevelDecls;
 162   IncludeStructure Includes;
 163   include_cleaner::PragmaIncludes PI;
 164   std::unique_ptr<HeuristicResolver> Resolver;
 165 };
 166
 167 } // namespace clangd
 168 } // namespace clang
 169
 170 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_PARSEDAST_H