1//===-- DWARFAbbreviationDeclaration.cpp ------------------------*- 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#include "DWARFAbbreviationDeclaration.h"
10
11#include "lldb/Core/dwarf.h"
12#include "lldb/Utility/Stream.h"
13
14#include "llvm/Object/Error.h"
15
16#include "DWARFFormValue.h"
17
18using namespace lldb_private;
19
20DWARFAbbreviationDeclaration::DWARFAbbreviationDeclaration()
21    : m_code(InvalidCode), m_tag(llvm::dwarf::DW_TAG_null), m_has_children(0),
22      m_attributes() {}
23
24DWARFAbbreviationDeclaration::DWARFAbbreviationDeclaration(dw_tag_t tag,
25                                                           uint8_t has_children)
26    : m_code(InvalidCode), m_tag(tag), m_has_children(has_children),
27      m_attributes() {}
28
29llvm::Expected<DWARFEnumState>
30DWARFAbbreviationDeclaration::extract(const DWARFDataExtractor &data,
31                                      lldb::offset_t *offset_ptr) {
32  m_code = data.GetULEB128(offset_ptr);
33  if (m_code == 0)
34    return DWARFEnumState::Complete;
35
36  m_attributes.clear();
37  m_tag = static_cast<dw_tag_t>(data.GetULEB128(offset_ptr));
38  if (m_tag == DW_TAG_null)
39    return llvm::make_error<llvm::object::GenericBinaryError>(
40        "abbrev decl requires non-null tag.");
41
42  m_has_children = data.GetU8(offset_ptr);
43
44  while (data.ValidOffset(*offset_ptr)) {
45    dw_attr_t attr = data.GetULEB128(offset_ptr);
46    dw_form_t form = data.GetULEB128(offset_ptr);
47
48    // This is the last attribute for this abbrev decl, but there may still be
49    // more abbrev decls, so return MoreItems to indicate to the caller that
50    // they should call this function again.
51    if (!attr && !form)
52      return DWARFEnumState::MoreItems;
53
54    if (!attr || !form)
55      return llvm::make_error<llvm::object::GenericBinaryError>(
56          "malformed abbreviation declaration attribute");
57
58    DWARFFormValue::ValueType val;
59
60    if (form == DW_FORM_implicit_const)
61      val.value.sval = data.GetULEB128(offset_ptr);
62
63    m_attributes.push_back(DWARFAttribute(attr, form, val));
64  }
65
66  return llvm::make_error<llvm::object::GenericBinaryError>(
67      "abbreviation declaration attribute list not terminated with a null "
68      "entry");
69}
70
71bool DWARFAbbreviationDeclaration::IsValid() {
72  return m_code != 0 && m_tag != llvm::dwarf::DW_TAG_null;
73}
74
75uint32_t
76DWARFAbbreviationDeclaration::FindAttributeIndex(dw_attr_t attr) const {
77  uint32_t i;
78  const uint32_t kNumAttributes = m_attributes.size();
79  for (i = 0; i < kNumAttributes; ++i) {
80    if (m_attributes[i].get_attr() == attr)
81      return i;
82  }
83  return DW_INVALID_INDEX;
84}
85
86bool DWARFAbbreviationDeclaration::
87operator==(const DWARFAbbreviationDeclaration &rhs) const {
88  return Tag() == rhs.Tag() && HasChildren() == rhs.HasChildren() &&
89         m_attributes == rhs.m_attributes;
90}
91