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 Sema;
  42 namespace clangd {
  43 class HeuristicResolver;
  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   /// Note that the returned ast will not contain decls from the preamble that
  63   /// were not deserialized during parsing. Clients should expect only decls
  64   /// from the main file to be in the AST.
  65   ASTContext &getASTContext();
  66   const ASTContext &getASTContext() const;
  67
  68   Sema &getSema();
  69
  70   Preprocessor &getPreprocessor();
  71   std::shared_ptr<Preprocessor> getPreprocessorPtr();
  72   const Preprocessor &getPreprocessor() const;
  73
  74   SourceManager &getSourceManager() {
  75     return getASTContext().getSourceManager();
  76   }
  77   const SourceManager &getSourceManager() const {
  78     return getASTContext().getSourceManager();
  79   }
  80
  81   const LangOptions &getLangOpts() const {
  82     return getASTContext().getLangOpts();
  83   }
  84
  85   /// This function returns top-level decls present in the main file of the AST.
  86   /// The result does not include the decls that come from the preamble.
  87   /// (These should be const, but RecursiveASTVisitor requires Decl*).
  88   ArrayRef<Decl *> getLocalTopLevelDecls();
  89   ArrayRef<const Decl *> getLocalTopLevelDecls() const;
  90
  91   llvm::ArrayRef<Diag> getDiagnostics() const;
  92
  93   /// Returns the estimated size of the AST and the accessory structures, in
  94   /// bytes. Does not include the size of the preamble.
  95   std::size_t getUsedBytes() const;
  96   const IncludeStructure &getIncludeStructure() const;
  97
  98   /// Gets all macro references (definition, expansions) present in the main
  99   /// file, including those in the preamble region.
 100   const MainFileMacros &getMacros() const;
 101   /// Gets all pragma marks in the main file.
 102   const std::vector<PragmaMark> &getMarks() const;
 103   /// Tokens recorded while parsing the main file.
 104   /// (!) does not have tokens from the preamble.
 105   const syntax::TokenBuffer &getTokens() const { return Tokens; }
 106   /// Returns the PramaIncludes for preamble + main file includes.
 107   const include_cleaner::PragmaIncludes &getPragmaIncludes() const;
 108
 109   /// Returns the version of the ParseInputs this AST was built from.
 110   llvm::StringRef version() const { return Version; }
 111
 112   /// Returns the path passed by the caller when building this AST.
 113   PathRef tuPath() const { return TUPath; }
 114
 115   /// Returns the version of the ParseInputs used to build Preamble part of this
 116   /// AST. Might be std::nullopt if no Preamble is used.
 117   std::optional<llvm::StringRef> preambleVersion() const;
 118
 119   const HeuristicResolver *getHeuristicResolver() const {
 120     return Resolver.get();
 121   }
 122
 123 private:
 124   ParsedAST(PathRef TUPath, llvm::StringRef Version,
 125             std::shared_ptr<const PreambleData> Preamble,
 126             std::unique_ptr<CompilerInstance> Clang,
 127             std::unique_ptr<FrontendAction> Action, syntax::TokenBuffer Tokens,
 128             MainFileMacros Macros, std::vector<PragmaMark> Marks,
 129             std::vector<Decl *> LocalTopLevelDecls, std::vector<Diag> Diags,
 130             IncludeStructure Includes, include_cleaner::PragmaIncludes PI);
 131   Path TUPath;
 132   std::string Version;
 133   // In-memory preambles must outlive the AST, it is important that this member
 134   // goes before Clang and Action.
 135   std::shared_ptr<const PreambleData> Preamble;
 136   // We store an "incomplete" FrontendAction (i.e. no EndSourceFile was called
 137   // on it) and CompilerInstance used to run it. That way we don't have to do
 138   // complex memory management of all Clang structures on our own. (They are
 139   // stored in CompilerInstance and cleaned up by
 140   // FrontendAction.EndSourceFile).
 141   std::unique_ptr<CompilerInstance> Clang;
 142   std::unique_ptr<FrontendAction> Action;
 143   /// Tokens recorded after the preamble finished.
 144   ///   - Includes all spelled tokens for the main file.
 145   ///   - Includes expanded tokens produced **after** preamble.
 146   ///   - Does not have spelled or expanded tokens for files from preamble.
 147   syntax::TokenBuffer Tokens;
 148
 149   /// All macro definitions and expansions in the main file.
 150   MainFileMacros Macros;
 151   // Pragma marks in the main file.
 152   std::vector<PragmaMark> Marks;
 153   // Diags emitted while parsing this AST (including preamble and compiler
 154   // invocation).
 155   std::vector<Diag> Diags;
 156   // Top-level decls inside the current file. Not that this does not include
 157   // top-level decls from the preamble.
 158   std::vector<Decl *> LocalTopLevelDecls;
 159   IncludeStructure Includes;
 160   include_cleaner::PragmaIncludes PI;
 161   std::unique_ptr<HeuristicResolver> Resolver;
 162 };
 163
 164 } // namespace clangd
 165 } // namespace clang
 166
 167 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_PARSEDAST_H