a2154b1951
This patch add the ability to cache the manual DWARF indexing results to disk for faster subsequent debug sessions. Manual DWARF indexing is time consuming and causes all DWARF to be fully parsed and indexed each time you debug a binary that doesn't have an acceptable accelerator table. Acceptable accelerator tables include .debug_names in DWARF5 or Apple accelerator tables. This patch breaks up testing by testing all of the encoding and decoding of required C++ objects in a gtest unit test, and then has a test to verify the debug info cache is generated correctly. This patch also adds the ability to track when a symbol table or DWARF index is loaded or saved to the cache in the "statistics dump" command. This is essential to know in statistics as it can help explain why a debug session was slower or faster than expected. Reviewed By: labath, wallace Differential Revision: https://reviews.llvm.org/D115951
56 lines
2.1 KiB
C++
56 lines
2.1 KiB
C++
//===-- DIERef.cpp --------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "DIERef.h"
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#include "lldb/Utility/DataEncoder.h"
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#include "lldb/Utility/DataExtractor.h"
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#include "llvm/Support/Format.h"
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using namespace lldb;
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using namespace lldb_private;
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void llvm::format_provider<DIERef>::format(const DIERef &ref, raw_ostream &OS,
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StringRef Style) {
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if (ref.dwo_num())
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OS << format_hex_no_prefix(*ref.dwo_num(), 8) << "/";
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OS << (ref.section() == DIERef::DebugInfo ? "INFO" : "TYPE");
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OS << "/" << format_hex_no_prefix(ref.die_offset(), 8);
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}
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constexpr uint32_t k_dwo_num_mask = 0x3FFFFFFF;
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constexpr uint32_t k_dwo_num_valid_bitmask = (1u << 30);
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constexpr uint32_t k_section_bitmask = (1u << 31);
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llvm::Optional<DIERef> DIERef::Decode(const DataExtractor &data,
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lldb::offset_t *offset_ptr) {
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const uint32_t bitfield_storage = data.GetU32(offset_ptr);
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uint32_t dwo_num = bitfield_storage & k_dwo_num_mask;
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bool dwo_num_valid = (bitfield_storage & (k_dwo_num_valid_bitmask)) != 0;
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Section section = (Section)((bitfield_storage & (k_section_bitmask)) != 0);
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// DIE offsets can't be zero and if we fail to decode something from data,
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// it will return 0
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dw_offset_t die_offset = data.GetU32(offset_ptr);
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if (die_offset == 0)
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return llvm::None;
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if (dwo_num_valid)
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return DIERef(dwo_num, section, die_offset);
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else
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return DIERef(llvm::None, section, die_offset);
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}
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void DIERef::Encode(DataEncoder &encoder) const {
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uint32_t bitfield_storage = m_dwo_num;
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if (m_dwo_num_valid)
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bitfield_storage |= k_dwo_num_valid_bitmask;
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if (m_section)
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bitfield_storage |= k_section_bitmask;
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encoder.AppendU32(bitfield_storage);
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static_assert(sizeof(m_die_offset) == 4, "m_die_offset must be 4 bytes");
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encoder.AppendU32(m_die_offset);
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}
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