clang-tools-extra/include-cleaner/lib/TypesInternal.h

   1 //===--- TypesInternal.h - Intermediate structures used for analysis 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 #ifndef CLANG_INCLUDE_CLEANER_TYPESINTERNAL_H
  10 #define CLANG_INCLUDE_CLEANER_TYPESINTERNAL_H
  11
  12 #include "clang/Basic/SourceLocation.h"
  13 #include "clang/Tooling/Inclusions/StandardLibrary.h"
  14 #include "llvm/ADT/BitmaskEnum.h"
  15 #include <cstdint>
  16 #include <utility>
  17 #include <variant>
  18
  19 namespace llvm {
  20 class raw_ostream;
  21 }
  22 namespace clang::include_cleaner {
  23 /// A place where a symbol can be provided.
  24 /// It is either a physical file of the TU (SourceLocation) or a logical
  25 /// location in the standard library (stdlib::Symbol).
  26 struct SymbolLocation {
  27   enum Kind {
  28     /// A position within a source file (or macro expansion) parsed by clang.
  29     Physical,
  30     /// A recognized standard library symbol, like std::string.
  31     Standard,
  32   };
  33
  34   SymbolLocation(SourceLocation S) : Storage(S) {}
  35   SymbolLocation(tooling::stdlib::Symbol S) : Storage(S) {}
  36
  37   Kind kind() const { return static_cast<Kind>(Storage.index()); }
  38   bool operator==(const SymbolLocation &RHS) const {
  39     return Storage == RHS.Storage;
  40   }
  41   SourceLocation physical() const { return std::get<Physical>(Storage); }
  42   tooling::stdlib::Symbol standard() const {
  43     return std::get<Standard>(Storage);
  44   }
  45
  46 private:
  47   // Order must match Kind enum!
  48   std::variant<SourceLocation, tooling::stdlib::Symbol> Storage;
  49 };
  50 llvm::raw_ostream &operator<<(llvm::raw_ostream &, const SymbolLocation &);
  51
  52 /// Represents properties of a symbol provider.
  53 ///
  54 /// Hints represents the properties of the edges traversed when finding headers
  55 /// that satisfy an AST node (AST node => symbols => locations => headers).
  56 ///
  57 /// Since there can be multiple paths from an AST node to same header, we need
  58 /// to merge hints. These hints are merged by taking the union of all the
  59 /// properties along all the paths. We choose the boolean sense accordingly,
  60 /// e.g. "Public" rather than "Private", because a header is good if it provides
  61 /// any public definition, even if it also provides private ones.
  62 ///
  63 /// Hints are sorted in ascending order of relevance.
  64 enum class Hints : uint8_t {
  65   None = 0x00,
  66   /// Symbol is directly originating from this header, rather than being
  67   /// exported or included transitively.
  68   OriginHeader = 1 << 0,
  69   /// Provides a generally-usable definition for the symbol. (a function decl,
  70   /// or class definition and not a forward declaration of a template).
  71   CompleteSymbol = 1 << 1,
  72   /// Symbol is provided by a public file. Only absent in the cases where file
  73   /// is explicitly marked as such, non self-contained or IWYU private
  74   /// pragmas.
  75   PublicHeader = 1 << 2,
  76   /// Header providing the symbol is explicitly marked as preferred, with an
  77   /// IWYU private pragma that points at this provider or header and symbol has
  78   /// ~the same name.
  79   PreferredHeader = 1 << 3,
  80   LLVM_MARK_AS_BITMASK_ENUM(PreferredHeader),
  81 };
  82 LLVM_ENABLE_BITMASK_ENUMS_IN_NAMESPACE();
  83 /// A wrapper to augment values with hints.
  84 template <typename T> struct Hinted : public T {
  85   Hints Hint;
  86   Hinted(T &&Wrapped, Hints H) : T(std::move(Wrapped)), Hint(H) {}
  87
  88   /// Since hints are sorted by relevance, use it directly.
  89   bool operator<(const Hinted<T> &Other) const {
  90     return static_cast<int>(Hint) < static_cast<int>(Other.Hint);
  91   }
  92
  93   friend llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
  94                                        const Hinted<T> &H) {
  95     return OS << static_cast<int>(H.Hint) << " - " << static_cast<T>(H);
  96   }
  97 };
  98
  99 } // namespace clang::include_cleaner
 100
 101 #endif