android_system_core/libunwindstack/include/unwindstack/DwarfLocation.h
David Srbecky 3386ebade2 Cache DWARF location rules for a given pc.
Decoding the DWARF opcodes is expensive so make sure we cache it.

This speeds unwinding in simpleperf by over a factor of 3x.

Add unit tests for this new behavior.

Bug: 77258731

Test: libbacktrace/libunwindstack unit tests on host and target.
Test: Ran debuggerd -b on various processes on target.
Change-Id: Ia516c0fa5d3e5f76746190bb4b6fdf49fd1c9388
2018-03-29 14:47:13 +00:00

53 lines
1.4 KiB
C++

/*
* 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 _LIBUNWINDSTACK_DWARF_LOCATION_H
#define _LIBUNWINDSTACK_DWARF_LOCATION_H
#include <stdint.h>
#include <unordered_map>
namespace unwindstack {
struct DwarfCie;
enum DwarfLocationEnum : uint8_t {
DWARF_LOCATION_INVALID = 0,
DWARF_LOCATION_UNDEFINED,
DWARF_LOCATION_OFFSET,
DWARF_LOCATION_VAL_OFFSET,
DWARF_LOCATION_REGISTER,
DWARF_LOCATION_EXPRESSION,
DWARF_LOCATION_VAL_EXPRESSION,
};
struct DwarfLocation {
DwarfLocationEnum type;
uint64_t values[2];
};
struct DwarfLocations : public std::unordered_map<uint32_t, DwarfLocation> {
const DwarfCie* cie;
// The range of PCs where the locations are valid (end is exclusive).
uint64_t pc_start = 0;
uint64_t pc_end = 0;
};
typedef DwarfLocations dwarf_loc_regs_t;
} // namespace unwindstack
#endif // _LIBUNWINDSTACK_DWARF_LOCATION_H