diff options
Diffstat (limited to 'Userland/Libraries/LibDebug/Dwarf/DIE.cpp')
| -rw-r--r-- | Userland/Libraries/LibDebug/Dwarf/DIE.cpp | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/Userland/Libraries/LibDebug/Dwarf/DIE.cpp b/Userland/Libraries/LibDebug/Dwarf/DIE.cpp new file mode 100644 index 0000000000..96ad0875d6 --- /dev/null +++ b/Userland/Libraries/LibDebug/Dwarf/DIE.cpp @@ -0,0 +1,244 @@ +/* + * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "DIE.h" +#include "CompilationUnit.h" +#include "DwarfInfo.h" +#include <AK/ByteBuffer.h> +#include <AK/MemoryStream.h> + +namespace Debug::Dwarf { + +DIE::DIE(const CompilationUnit& unit, u32 offset) + : m_compilation_unit(unit) + , m_offset(offset) +{ + InputMemoryStream stream(m_compilation_unit.dwarf_info().debug_info_data()); + stream.discard_or_error(m_offset); + stream.read_LEB128_unsigned(m_abbreviation_code); + m_data_offset = stream.offset(); + + if (m_abbreviation_code == 0) { + // An abbreviation code of 0 ( = null DIE entry) means the end of a chain of siblings + m_tag = EntryTag::None; + } else { + auto abbreviation_info = m_compilation_unit.abbreviations_map().get(m_abbreviation_code); + ASSERT(abbreviation_info.has_value()); + + m_tag = abbreviation_info.value().tag; + m_has_children = abbreviation_info.value().has_children; + + // We iterate the attributes data only to calculate this DIE's size + for (auto& attribute_spec : abbreviation_info.value().attribute_specifications) { + get_attribute_value(attribute_spec.form, stream); + } + } + m_size = stream.offset() - m_offset; +} + +DIE::AttributeValue DIE::get_attribute_value(AttributeDataForm form, + InputMemoryStream& debug_info_stream) const +{ + AttributeValue value; + + auto assign_raw_bytes_value = [&](size_t length) { + value.data.as_raw_bytes.length = length; + value.data.as_raw_bytes.bytes = reinterpret_cast<const u8*>(m_compilation_unit.dwarf_info().debug_info_data().data() + + debug_info_stream.offset()); + + debug_info_stream.discard_or_error(length); + }; + + switch (form) { + case AttributeDataForm::StringPointer: { + u32 offset; + debug_info_stream >> offset; + value.type = AttributeValue::Type::String; + + auto strings_data = m_compilation_unit.dwarf_info().debug_strings_data(); + value.data.as_string = reinterpret_cast<const char*>(strings_data.data() + offset); + break; + } + case AttributeDataForm::Data1: { + u8 data; + debug_info_stream >> data; + value.type = AttributeValue::Type::UnsignedNumber; + value.data.as_u32 = data; + break; + } + case AttributeDataForm::Data2: { + u16 data; + debug_info_stream >> data; + value.type = AttributeValue::Type::UnsignedNumber; + value.data.as_u32 = data; + break; + } + case AttributeDataForm::Addr: { + u32 address; + debug_info_stream >> address; + value.type = AttributeValue::Type::UnsignedNumber; + value.data.as_u32 = address; + break; + } + case AttributeDataForm::SData: { + ssize_t data; + debug_info_stream.read_LEB128_signed(data); + value.type = AttributeValue::Type::SignedNumber; + value.data.as_i32 = data; + break; + } + case AttributeDataForm::SecOffset: { + u32 data; + debug_info_stream >> data; + value.type = AttributeValue::Type::SecOffset; + value.data.as_u32 = data; + break; + } + case AttributeDataForm::Data4: { + u32 data; + debug_info_stream >> data; + value.type = AttributeValue::Type::UnsignedNumber; + value.data.as_u32 = data; + break; + } + case AttributeDataForm::Ref4: { + u32 data; + debug_info_stream >> data; + value.type = AttributeValue::Type::DieReference; + value.data.as_u32 = data + m_compilation_unit.offset(); + break; + } + case AttributeDataForm::FlagPresent: { + value.type = AttributeValue::Type::Boolean; + value.data.as_bool = true; + break; + } + case AttributeDataForm::ExprLoc: { + size_t length; + debug_info_stream.read_LEB128_unsigned(length); + value.type = AttributeValue::Type::DwarfExpression; + assign_raw_bytes_value(length); + break; + } + case AttributeDataForm::String: { + String str; + u32 str_offset = debug_info_stream.offset(); + debug_info_stream >> str; + value.type = AttributeValue::Type::String; + value.data.as_string = reinterpret_cast<const char*>(str_offset + m_compilation_unit.dwarf_info().debug_info_data().data()); + break; + } + case AttributeDataForm::Block1: { + value.type = AttributeValue::Type::RawBytes; + u8 length; + debug_info_stream >> length; + assign_raw_bytes_value(length); + break; + } + case AttributeDataForm::Block2: { + value.type = AttributeValue::Type::RawBytes; + u16 length; + debug_info_stream >> length; + assign_raw_bytes_value(length); + break; + } + case AttributeDataForm::Block4: { + value.type = AttributeValue::Type::RawBytes; + u32 length; + debug_info_stream >> length; + assign_raw_bytes_value(length); + break; + } + case AttributeDataForm::Block: { + value.type = AttributeValue::Type::RawBytes; + size_t length; + debug_info_stream.read_LEB128_unsigned(length); + assign_raw_bytes_value(length); + break; + } + default: + dbgln("Unimplemented AttributeDataForm: {}", (u32)form); + ASSERT_NOT_REACHED(); + } + return value; +} + +Optional<DIE::AttributeValue> DIE::get_attribute(const Attribute& attribute) const +{ + InputMemoryStream stream { m_compilation_unit.dwarf_info().debug_info_data() }; + stream.discard_or_error(m_data_offset); + + auto abbreviation_info = m_compilation_unit.abbreviations_map().get(m_abbreviation_code); + ASSERT(abbreviation_info.has_value()); + + for (const auto& attribute_spec : abbreviation_info.value().attribute_specifications) { + auto value = get_attribute_value(attribute_spec.form, stream); + if (attribute_spec.attribute == attribute) { + return value; + } + } + return {}; +} + +void DIE::for_each_child(Function<void(const DIE& child)> callback) const +{ + if (!m_has_children) + return; + + NonnullOwnPtr<DIE> current_child = make<DIE>(m_compilation_unit, m_offset + m_size); + while (true) { + callback(*current_child); + if (current_child->is_null()) + break; + if (!current_child->has_children()) { + current_child = make<DIE>(m_compilation_unit, current_child->offset() + current_child->size()); + continue; + } + + auto sibling = current_child->get_attribute(Attribute::Sibling); + u32 sibling_offset = 0; + if (sibling.has_value()) { + sibling_offset = sibling.value().data.as_u32; + } + + if (!sibling.has_value()) { + // NOTE: According to the spec, the compiler doesn't have to supply the sibling information. + // When it doesn't, we have to recursively iterate the current child's children to find where they end + current_child->for_each_child([&](const DIE& sub_child) { + sibling_offset = sub_child.offset() + sub_child.size(); + }); + } + current_child = make<DIE>(m_compilation_unit, sibling_offset); + } +} + +DIE DIE::get_die_at_offset(u32 offset) const +{ + ASSERT(offset >= m_compilation_unit.offset() && offset < m_compilation_unit.offset() + m_compilation_unit.size()); + return DIE(m_compilation_unit, offset); +} + +} |