| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ART_COMPILER_DEBUG_DWARF_DEBUG_ABBREV_WRITER_H_ |
| #define ART_COMPILER_DEBUG_DWARF_DEBUG_ABBREV_WRITER_H_ |
| |
| #include <cstdint> |
| #include <type_traits> |
| #include <unordered_map> |
| |
| #include "base/casts.h" |
| #include "base/leb128.h" |
| #include "base/stl_util.h" |
| #include "debug/dwarf/dwarf_constants.h" |
| #include "debug/dwarf/writer.h" |
| |
| namespace art { |
| namespace dwarf { |
| |
| // Writer for the .debug_abbrev. |
| // |
| // Abbreviations specify the format of entries in .debug_info. |
| // Each entry specifies abbreviation code, which in turns |
| // determines all the attributes and their format. |
| // It is possible to think of them as type definitions. |
| template <typename Vector = std::vector<uint8_t>> |
| class DebugAbbrevWriter final : private Writer<Vector> { |
| static_assert(std::is_same<typename Vector::value_type, uint8_t>::value, "Invalid value type"); |
| |
| public: |
| explicit DebugAbbrevWriter(Vector* buffer) |
| : Writer<Vector>(buffer), |
| current_abbrev_(buffer->get_allocator()) { |
| this->PushUint8(0); // Add abbrev table terminator. |
| } |
| |
| // Start abbreviation declaration. |
| void StartAbbrev(Tag tag) { |
| DCHECK(current_abbrev_.empty()); |
| EncodeUnsignedLeb128(¤t_abbrev_, tag); |
| has_children_offset_ = current_abbrev_.size(); |
| current_abbrev_.push_back(0); // Place-holder for DW_CHILDREN. |
| } |
| |
| // Add attribute specification. |
| void AddAbbrevAttribute(Attribute name, Form type) { |
| EncodeUnsignedLeb128(¤t_abbrev_, name); |
| EncodeUnsignedLeb128(¤t_abbrev_, type); |
| } |
| |
| // End abbreviation declaration and return its code. |
| // This will deduplicate abbreviations. |
| uint32_t EndAbbrev(Children has_children) { |
| DCHECK(!current_abbrev_.empty()); |
| current_abbrev_[has_children_offset_] = has_children; |
| auto it = abbrev_codes_.insert(std::make_pair(std::move(current_abbrev_), NextAbbrevCode())); |
| uint32_t abbrev_code = it.first->second; |
| if (UNLIKELY(it.second)) { // Inserted new entry. |
| const Vector& abbrev = it.first->first; |
| this->Pop(); // Remove abbrev table terminator. |
| this->PushUleb128(abbrev_code); |
| this->PushData(abbrev.data(), abbrev.size()); |
| this->PushUint8(0); // Attribute list end. |
| this->PushUint8(0); // Attribute list end. |
| this->PushUint8(0); // Add abbrev table terminator. |
| } |
| current_abbrev_.clear(); |
| return abbrev_code; |
| } |
| |
| // Get the next free abbrev code. |
| uint32_t NextAbbrevCode() { |
| return dchecked_integral_cast<uint32_t>(1 + abbrev_codes_.size()); |
| } |
| |
| private: |
| Vector current_abbrev_; |
| size_t has_children_offset_ = 0; |
| std::unordered_map<Vector, uint32_t, FNVHash<Vector> > abbrev_codes_; |
| }; |
| |
| } // namespace dwarf |
| } // namespace art |
| |
| #endif // ART_COMPILER_DEBUG_DWARF_DEBUG_ABBREV_WRITER_H_ |