xref: /llvm-project/clang-tools-extra/clangd/ParsedAST.h (revision ae932becb2c952876edbb3591bfa997bf4629a4d)
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
171