DWARFDebugInfoEntry.h

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//===-- DWARFDebugInfoEntry.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_DWARFDEBUGINFOENTRY_H
#define LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFDEBUGINFOENTRY_H
 
#include "SymbolFileDWARF.h"
 
#include "DWARFAttribute.h"
#include "DWARFBaseDIE.h"
#include <map>
#include <optional>
#include <set>
#include <vector>
 
#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
 
namespace lldb_private::plugin {
namespace dwarf {
class DWARFDeclContext;
 
#define DIE_SIBLING_IDX_BITSIZE 31
 
/// DWARFDebugInfoEntry objects assume that they are living in one big
/// vector and do pointer arithmetic on their this pointers. Don't
/// pass them by value. Due to the way they are constructed in a
/// std::vector, we cannot delete the copy constructor.
class DWARFDebugInfoEntry {
public:
  typedef std::vector<DWARFDebugInfoEntry> collection;
  typedef collection::iterator iterator;
  typedef collection::const_iterator const_iterator;
 
  DWARFDebugInfoEntry()
      : m_offset(DW_INVALID_OFFSET), m_parent_idx(0), m_sibling_idx(0),
        m_has_children(false) {}
 
  explicit operator bool() const { return m_offset != DW_INVALID_OFFSET; }
  bool operator==(const DWARFDebugInfoEntry &rhs) const;
  bool operator!=(const DWARFDebugInfoEntry &rhs) const;
 
  void BuildFunctionAddressRangeTable(DWARFUnit *cu,
                                      DWARFDebugAranges *debug_aranges) const;
 
  bool Extract(const DWARFDataExtractor &data, const DWARFUnit &cu,
               lldb::offset_t *offset_ptr);
 
  using Recurse = DWARFBaseDIE::Recurse;
 
  /// Get all attribute values for a given DIE, optionally following any
  /// specifications and abstract origins and including their attributes
  /// in the result too.
  ///
  /// When following specifications/abstract origins, the attributes
  /// on the referring DIE are guaranteed to be visited before the attributes of
  /// the referenced DIE.
  ///
  /// \param[in] cu DWARFUnit that this entry belongs to.
  ///
  /// \param[in] recurse If set to \c Recurse::yes, will include attributes
  /// on DIEs referenced via \c DW_AT_specification and \c DW_AT_abstract_origin
  /// (including across multiple levels of indirection).
  ///
  /// \returns DWARFAttributes that include all attributes found on this DIE
  /// (and possibly referenced DIEs). Attributes may appear multiple times
  /// (e.g., if a declaration and definition both specify the same attribute).
  /// On failure, the returned DWARFAttributes will be empty.
  ///
  DWARFAttributes GetAttributes(const DWARFUnit *cu,
                                Recurse recurse = Recurse::yes) const;
 
  dw_offset_t GetAttributeValue(const DWARFUnit *cu, const dw_attr_t attr,
                                DWARFFormValue &formValue,
                                dw_offset_t *end_attr_offset_ptr = nullptr,
                                bool check_elaborating_dies = false) const;
 
  const char *
  GetAttributeValueAsString(const DWARFUnit *cu, const dw_attr_t attr,
                            const char *fail_value,
                            bool check_elaborating_dies = false) const;
 
  uint64_t
  GetAttributeValueAsUnsigned(const DWARFUnit *cu, const dw_attr_t attr,
                              uint64_t fail_value,
                              bool check_elaborating_dies = false) const;
 
  std::optional<uint64_t> GetAttributeValueAsOptionalUnsigned(
      const DWARFUnit *cu, const dw_attr_t attr,
      bool check_elaborating_dies = false) const;
 
  DWARFDIE
  GetAttributeValueAsReference(const DWARFUnit *cu, const dw_attr_t attr,
                               bool check_elaborating_dies = false) const;
 
  uint64_t
  GetAttributeValueAsAddress(const DWARFUnit *cu, const dw_attr_t attr,
                             uint64_t fail_value,
                             bool check_elaborating_dies = false) const;
 
  dw_addr_t GetAttributeHighPC(const DWARFUnit *cu, dw_addr_t lo_pc,
                               uint64_t fail_value,
                               bool check_elaborating_dies = false) const;
 
  bool GetAttributeAddressRange(const DWARFUnit *cu, dw_addr_t &lo_pc,
                                dw_addr_t &hi_pc, uint64_t fail_value,
                                bool check_elaborating_dies = false) const;
 
  llvm::Expected<llvm::DWARFAddressRangesVector>
  GetAttributeAddressRanges(DWARFUnit *cu, bool check_hi_lo_pc,
                            bool check_elaborating_dies = false) const;
 
  const char *GetName(const DWARFUnit *cu) const;
 
  const char *GetMangledName(const DWARFUnit *cu,
                             bool substitute_name_allowed = true) const;
 
  const char *GetPubname(const DWARFUnit *cu) const;
 
  bool GetDIENamesAndRanges(
      DWARFUnit *cu, const char *&name, const char *&mangled,
      llvm::DWARFAddressRangesVector &rangeList, 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 = nullptr) const;
 
  const llvm::DWARFAbbreviationDeclaration *
  GetAbbreviationDeclarationPtr(const DWARFUnit *cu) const;
 
  lldb::offset_t GetFirstAttributeOffset() const;
 
  dw_tag_t Tag() const { return m_tag; }
 
  bool IsNULL() const { return m_abbr_idx == 0; }
 
  dw_offset_t GetOffset() const { return m_offset; }
 
  bool HasChildren() const { return m_has_children; }
 
  void SetHasChildren(bool b) { m_has_children = b; }
 
  // We know we are kept in a vector of contiguous entries, so we know
  // our parent will be some index behind "this".
  DWARFDebugInfoEntry *GetParent() {
    return m_parent_idx > 0 ? this - m_parent_idx : nullptr;
  }
  const DWARFDebugInfoEntry *GetParent() const {
    return m_parent_idx > 0 ? this - m_parent_idx : nullptr;
  }
  // We know we are kept in a vector of contiguous entries, so we know
  // our sibling will be some index after "this".
  DWARFDebugInfoEntry *GetSibling() {
    return m_sibling_idx > 0 ? this + m_sibling_idx : nullptr;
  }
  const DWARFDebugInfoEntry *GetSibling() const {
    return m_sibling_idx > 0 ? this + m_sibling_idx : nullptr;
  }
  // We know we are kept in a vector of contiguous entries, so we know
  // we don't need to store our child pointer, if we have a child it will
  // be the next entry in the list...
  DWARFDebugInfoEntry *GetFirstChild() {
    return HasChildren() ? this + 1 : nullptr;
  }
  const DWARFDebugInfoEntry *GetFirstChild() const {
    return HasChildren() ? this + 1 : nullptr;
  }
 
  void SetSiblingIndex(uint32_t idx) { m_sibling_idx = idx; }
  void SetParentIndex(uint32_t idx) { m_parent_idx = idx; }
 
  // This function returns true if the variable scope is either
  // global or (file-static). It will return false for static variables
  // that are local to a function, as they have local scope.
  bool IsGlobalOrStaticScopeVariable() const;
 
protected:
  // Up to 2TB offset within the .debug_info/.debug_types
  dw_offset_t m_offset : DW_DIE_OFFSET_MAX_BITSIZE;
  // How many to subtract from "this" to get the parent. If zero this die has no
  // parent
  dw_offset_t m_parent_idx : 64 - DW_DIE_OFFSET_MAX_BITSIZE;
  // How many to add to "this" to get the sibling.
  // If it is zero, then the DIE doesn't have children,
  // or the DWARF claimed it had children but the DIE
  // only contained a single NULL terminating child.
  uint32_t m_sibling_idx : 31, m_has_children : 1;
  uint16_t m_abbr_idx = 0;
  /// A copy of the DW_TAG value so we don't have to go through the compile
  /// unit abbrev table
  dw_tag_t m_tag = llvm::dwarf::DW_TAG_null;
};
} // namespace dwarf
} // namespace lldb_private::plugin
 
#endif // LLDB_SOURCE_PLUGINS_SYMBOLFILE_DWARF_DWARFDEBUGINFOENTRY_H