SourceLocation.h

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//===- SourceLocation.h - Compact identifier for Source Files ---*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file
/// Defines the clang::SourceLocation class and associated facilities.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CLANG_BASIC_SOURCELOCATION_H
#define LLVM_CLANG_BASIC_SOURCELOCATION_H
 
#include "clang/Basic/FileEntry.h"
#include "clang/Basic/LLVM.h"
#include "llvm/ADT/StringRef.h"
#include <cassert>
#include <cstdint>
#include <string>
#include <utility>
 
namespace llvm {
 
class FoldingSetNodeID;
template <typename T, typename Enable> struct FoldingSetTrait;
 
} // namespace llvm
 
namespace clang {
 
class SourceManager;
 
/// An opaque identifier used by SourceManager which refers to a
/// source file (MemoryBuffer) along with its \#include path and \#line data.
///
class FileID {
  /// A mostly-opaque identifier, where 0 is "invalid", >0 is
  /// this module, and <-1 is something loaded from another module.
  int ID = 0;
 
public:
  bool isValid() const { return ID != 0; }
  bool isInvalid() const { return ID == 0; }
 
  bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
  bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
  bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
  bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
  bool operator>(const FileID &RHS) const { return RHS < *this; }
  bool operator>=(const FileID &RHS) const { return RHS <= *this; }
 
  static FileID getSentinel() { return get(-1); }
  unsigned getHashValue() const { return static_cast<unsigned>(ID); }
 
private:
  friend class ASTWriter;
  friend class ASTReader;
  friend class SourceManager;
  friend class SourceManagerTestHelper;
 
  static FileID get(int V) {
    FileID F;
    F.ID = V;
    return F;
  }
 
  int getOpaqueValue() const { return ID; }
};
 
/// Encodes a location in the source. The SourceManager can decode this
/// to get at the full include stack, line and column information.
///
/// Technically, a source location is simply an offset into the manager's view
/// of the input source, which is all input buffers (including macro
/// expansions) concatenated in an effectively arbitrary order. The manager
/// actually maintains two blocks of input buffers. One, starting at offset
/// 0 and growing upwards, contains all buffers from this module. The other,
/// starting at the highest possible offset and growing downwards, contains
/// buffers of loaded modules.
///
/// In addition, one bit of SourceLocation is used for quick access to the
/// information whether the location is in a file or a macro expansion.
///
/// It is important that this type remains small. It is currently 32 bits wide.
class SourceLocation {
  friend class ASTReader;
  friend class ASTWriter;
  friend class SourceManager;
  friend struct llvm::FoldingSetTrait<SourceLocation, void>;
  friend class SourceLocationEncoding;
 
public:
  using UIntTy = uint32_t;
  using IntTy = int32_t;
 
private:
  UIntTy ID = 0;
 
  enum : UIntTy { MacroIDBit = 1ULL << (8 * sizeof(UIntTy) - 1) };
 
public:
  bool isFileID() const  { return (ID & MacroIDBit) == 0; }
  bool isMacroID() const { return (ID & MacroIDBit) != 0; }
 
  /// Return true if this is a valid SourceLocation object.
  ///
  /// Invalid SourceLocations are often used when events have no corresponding
  /// location in the source (e.g. a diagnostic is required for a command line
  /// option).
  bool isValid() const { return ID != 0; }
  bool isInvalid() const { return ID == 0; }
 
private:
  /// Return the offset into the manager's global input view.
  UIntTy getOffset() const { return ID & ~MacroIDBit; }
 
  static SourceLocation getFileLoc(UIntTy ID) {
    assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    SourceLocation L;
    L.ID = ID;
    return L;
  }
 
  static SourceLocation getMacroLoc(UIntTy ID) {
    assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
    SourceLocation L;
    L.ID = MacroIDBit | ID;
    return L;
  }
 
public:
  /// Return a source location with the specified offset from this
  /// SourceLocation.
  SourceLocation getLocWithOffset(IntTy Offset) const {
    assert(((getOffset()+Offset) & MacroIDBit) == 0 && "offset overflow");
    SourceLocation L;
    L.ID = ID+Offset;
    return L;
  }
 
  /// When a SourceLocation itself cannot be used, this returns
  /// an (opaque) 32-bit integer encoding for it.
  ///
  /// This should only be passed to SourceLocation::getFromRawEncoding, it
  /// should not be inspected directly.
  UIntTy getRawEncoding() const { return ID; }
 
  /// Turn a raw encoding of a SourceLocation object into
  /// a real SourceLocation.
  ///
  /// \see getRawEncoding.
  static SourceLocation getFromRawEncoding(UIntTy Encoding) {
    SourceLocation X;
    X.ID = Encoding;
    return X;
  }
 
  /// When a SourceLocation itself cannot be used, this returns
  /// an (opaque) pointer encoding for it.
  ///
  /// This should only be passed to SourceLocation::getFromPtrEncoding, it
  /// should not be inspected directly.
  void* getPtrEncoding() const {
    // Double cast to avoid a warning "cast to pointer from integer of different
    // size".
    return (void*)(uintptr_t)getRawEncoding();
  }
 
  /// Turn a pointer encoding of a SourceLocation object back
  /// into a real SourceLocation.
  static SourceLocation getFromPtrEncoding(const void *Encoding) {
    return getFromRawEncoding((SourceLocation::UIntTy)(uintptr_t)Encoding);
  }
 
  static bool isPairOfFileLocations(SourceLocation Start, SourceLocation End) {
    return Start.isValid() && Start.isFileID() && End.isValid() &&
           End.isFileID();
  }
 
  unsigned getHashValue() const;
  void print(raw_ostream &OS, const SourceManager &SM) const;
  std::string printToString(const SourceManager &SM) const;
  void dump(const SourceManager &SM) const;
};
 
inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
  return LHS.getRawEncoding() == RHS.