llvm-project/lldb/source/Plugins/SymbolFile/DWARF/DWARFDIE.h

//===-- DWARFDIE.h ----------------------------------------------*- 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
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFDIE_H
#define LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFDIE_H

#include "DWARFBaseDIE.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"

namespace lldb_private::plugin {
namespace dwarf {
class DWARFDIE : public DWARFBaseDIE {
public:
  class child_iterator;
  using DWARFBaseDIE::DWARFBaseDIE;

  // Tests
  bool IsStructUnionOrClass() const;

  bool IsMethod() const;

  // Accessors

  // Accessing information about a DIE
  const char *GetMangledName(bool substitute_name_allowed = true) const;

  const char *GetPubname() const;

  using DWARFBaseDIE::GetName;
  void GetName(Stream &s) const;

  void AppendTypeName(Stream &s) const;

  Type *ResolveType() const;

  // Resolve a type by UID using this DIE's DWARF file
  Type *ResolveTypeUID(const DWARFDIE &die) const;

  // Functions for obtaining DIE relations and references

  DWARFDIE
  GetParent() const;

  DWARFDIE
  GetFirstChild() const;

  DWARFDIE
  GetSibling() const;

  DWARFDIE
  GetReferencedDIE(const dw_attr_t attr) const;

  // Get a another DIE from the same DWARF file as this DIE. This will
  // check the current DIE's compile unit first to see if "die_offset" is
  // in the same compile unit, and fall back to checking the DWARF file.
  DWARFDIE
  GetDIE(dw_offset_t die_offset) const;
  using DWARFBaseDIE::GetDIE;

  DWARFDIE
  LookupDeepestBlock(lldb::addr_t file_addr) const;

  DWARFDIE
  GetParentDeclContextDIE() const;

  /// Return this DIE's decl context as it is needed to look up types
  /// in Clang modules. This context will include any modules or functions that
  /// the type is declared in so an exact module match can be efficiently made.
  ///
  /// \param[in] derive_template_names
  ///   If true, augments the returned names with template arguments derived
  ///   from the child DIEs, if the names don't contained template arguments
  ///   already. If false, the returned context will contain the names exactly
  ///   as they are spelled in the debug info, regardless of whether that
  ///   includes template arguments or not.
  std::vector<CompilerContext>
  GetDeclContext(bool derive_template_names = false) const;

  /// Get a context to a type so it can be looked up.
  ///
  /// This function uses the current DIE to fill in a CompilerContext array
  /// that is suitable for type lookup for comparison to a TypeQuery's compiler
  /// context (TypeQuery::GetContextRef()). If this DIE represents a named type,
  /// it should fill out the compiler context with the type itself as the last
  /// entry. The declaration context should be above the type and stop at an
  /// appropriate time, like either the translation unit or at a function
  /// context. This is designed to allow users to efficiently look for types
  /// using a full or partial CompilerContext array.
  ///
  /// \param[in] derive_template_names
  ///   If true, augments the returned names with template arguments derived
  ///   from the child DIEs, if the names don't contained template arguments
  ///   already. If false, the returned context will contain the names exactly
  ///   as they are spelled in the debug info, regardless of whether that
  ///   includes template arguments or not.
  std::vector<CompilerContext>
  GetTypeLookupContext(bool derive_template_names = false) const;

  DWARFDeclContext GetDWARFDeclContext() const;

  // Getting attribute values from the DIE.
  //
  // GetAttributeValueAsXXX() functions should only be used if you are
  // looking for one or two attributes on a DIE. If you are trying to
  // parse all attributes, use GetAttributes (...) instead
  DWARFDIE
  GetAttributeValueAsReferenceDIE(const dw_attr_t attr) const;

  bool GetDIENamesAndRanges(
      const char *&name, const char *&mangled,
      llvm::DWARFAddressRangesVector &ranges, std::optional<int> &decl_file,
      std::optional<int> &decl_line, std::optional<int> &decl_column,
      std::optional<int> &call_file, std::optional<int> &call_line,
      std::optional<int> &call_column, DWARFExpressionList *frame_base) const;

  // The following methods use LLVM naming convension in order to be are used by
  // LLVM libraries.
  std::optional<uint64_t> getLanguage() const;

  DWARFDIE getParent() const { return GetParent(); }

  DWARFDIE resolveReferencedType(dw_attr_t attr) const;

  DWARFDIE resolveReferencedType(DWARFFormValue v) const;

  DWARFDIE resolveTypeUnitReference() const;

  std::optional<DWARFFormValue> find(const dw_attr_t attr) const;

  /// The range of all the children of this DIE.
  llvm::iterator_range<child_iterator> children() const;

  child_iterator begin() const;
  child_iterator end() const;
};

class DWARFDIE::child_iterator
    : public llvm::iterator_facade_base<DWARFDIE::child_iterator,
                                        std::forward_iterator_tag, DWARFDIE> {
  /// The current child or an invalid DWARFDie.
  DWARFDIE m_die;

public:
  child_iterator() = default;
  child_iterator(const DWARFDIE &parent) : m_die(parent.GetFirstChild()) {}
  bool operator==(const child_iterator &it) const {
    // DWARFDIE's operator== differentiates between an invalid DWARFDIE that
    // has a CU but no DIE and one that has neither CU nor DIE. The 'end'
    // iterator could be default constructed, so explicitly allow
    // (CU, (DIE)nullptr) == (nullptr, nullptr) -> true
    if (!m_die.IsValid() && !it.m_die.IsValid())
      return true;
    return m_die == it.m_die;
  }
  const DWARFDIE &operator*() const {
    assert(m_die.IsValid() && "Derefencing invalid iterator?");
    return m_die;
  }
  DWARFDIE &operator*() {
    assert(m_die.IsValid() && "Derefencing invalid iterator?");
    return m_die;
  }
  child_iterator &operator++() {
    assert(m_die.IsValid() && "Incrementing invalid iterator?");
    m_die = m_die.GetSibling();
    return *this;
  }
};
} // namespace dwarf
} // namespace lldb_private::plugin

#endif // LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFDIE_H