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| //===-- DWARFDebugRanges.cpp ------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "DWARFDebugRanges.h"
#include "DWARFUnit.h"
#include "lldb/Utility/Stream.h"
using namespace lldb_private;
static dw_addr_t GetBaseAddressMarker(uint32_t addr_size) {
switch(addr_size) {
case 2:
return 0xffff;
case 4:
return 0xffffffff;
case 8:
return 0xffffffffffffffff;
}
llvm_unreachable("GetBaseAddressMarker unsupported address size.");
}
DWARFDebugRanges::DWARFDebugRanges() : m_range_map() {}
void DWARFDebugRanges::Extract(DWARFContext &context) {
DWARFRangeList range_list;
lldb::offset_t offset = 0;
dw_offset_t debug_ranges_offset = offset;
while (Extract(context, &offset, range_list)) {
range_list.Sort();
m_range_map[debug_ranges_offset] = range_list;
debug_ranges_offset = offset;
}
}
bool DWARFDebugRanges::Extract(DWARFContext &context,
lldb::offset_t *offset_ptr,
DWARFRangeList &range_list) {
range_list.Clear();
lldb::offset_t range_offset = *offset_ptr;
const DWARFDataExtractor &debug_ranges_data = context.getOrLoadRangesData();
uint32_t addr_size = debug_ranges_data.GetAddressByteSize();
dw_addr_t base_addr = 0;
dw_addr_t base_addr_marker = GetBaseAddressMarker(addr_size);
while (
debug_ranges_data.ValidOffsetForDataOfSize(*offset_ptr, 2 * addr_size)) {
dw_addr_t begin = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
dw_addr_t end = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
if (!begin && !end) {
// End of range list
break;
}
if (begin == base_addr_marker) {
base_addr = end;
continue;
}
// Filter out empty ranges
if (begin < end)
range_list.Append(DWARFRangeList::Entry(begin + base_addr, end - begin));
}
// Make sure we consumed at least something
return range_offset != *offset_ptr;
}
void DWARFDebugRanges::Dump(Stream &s,
const DWARFDataExtractor &debug_ranges_data,
lldb::offset_t *offset_ptr,
dw_addr_t cu_base_addr) {
uint32_t addr_size = s.GetAddressByteSize();
dw_addr_t base_addr = cu_base_addr;
while (
debug_ranges_data.ValidOffsetForDataOfSize(*offset_ptr, 2 * addr_size)) {
dw_addr_t begin = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
dw_addr_t end = debug_ranges_data.GetMaxU64(offset_ptr, addr_size);
// Extend 4 byte addresses that consists of 32 bits of 1's to be 64 bits of
// ones
if (begin == 0xFFFFFFFFull && addr_size == 4)
begin = LLDB_INVALID_ADDRESS;
s.Indent();
if (begin == 0 && end == 0) {
s.PutCString(" End");
break;
} else if (begin == LLDB_INVALID_ADDRESS) {
// A base address selection entry
base_addr = end;
s.Address(base_addr, sizeof(dw_addr_t), " Base address = ");
} else {
// Convert from offset to an address
dw_addr_t begin_addr = begin + base_addr;
dw_addr_t end_addr = end + base_addr;
s.AddressRange(begin_addr, end_addr, sizeof(dw_addr_t), nullptr);
}
}
}
bool DWARFDebugRanges::FindRanges(const DWARFUnit *cu,
dw_offset_t debug_ranges_offset,
DWARFRangeList &range_list) const {
dw_addr_t debug_ranges_address = cu->GetRangesBase() + debug_ranges_offset;
range_map_const_iterator pos = m_range_map.find(debug_ranges_address);
if (pos != m_range_map.end()) {
range_list = pos->second;
// All DW_AT_ranges are relative to the base address of the compile
// unit. We add the compile unit base address to make sure all the
// addresses are properly fixed up.
range_list.Slide(cu->GetBaseAddress());
return true;
}
return false;
}
bool DWARFDebugRngLists::ExtractRangeList(
const DWARFDataExtractor &data, uint8_t addrSize,
lldb::offset_t *offset_ptr, std::vector<RngListEntry> &rangeList) {
rangeList.clear();
bool error = false;
while (!error) {
switch (data.GetU8(offset_ptr)) {
case DW_RLE_end_of_list:
return true;
case DW_RLE_start_length: {
dw_addr_t begin = data.GetMaxU64(offset_ptr, addrSize);
dw_addr_t len = data.GetULEB128(offset_ptr);
rangeList.push_back({DW_RLE_start_length, begin, len});
break;
}
case DW_RLE_start_end: {
dw_addr_t begin = data.GetMaxU64(offset_ptr, addrSize);
dw_addr_t end = data.GetMaxU64(offset_ptr, addrSize);
rangeList.push_back({DW_RLE_start_end, begin, end});
break;
}
case DW_RLE_base_address: {
dw_addr_t base = data.GetMaxU64(offset_ptr, addrSize);
rangeList.push_back({DW_RLE_base_address, base, 0});
break;
}
case DW_RLE_offset_pair: {
dw_addr_t begin = data.GetULEB128(offset_ptr);
dw_addr_t end = data.GetULEB128(offset_ptr);
rangeList.push_back({DW_RLE_offset_pair, begin, end});
break;
}
case DW_RLE_base_addressx: {
dw_addr_t base = data.GetULEB128(offset_ptr);
rangeList.push_back({DW_RLE_base_addressx, base, 0});
break;
}
case DW_RLE_startx_endx: {
dw_addr_t start = data.GetULEB128(offset_ptr);
dw_addr_t end = data.GetULEB128(offset_ptr);
rangeList.push_back({DW_RLE_startx_endx, start, end});
break;
}
case DW_RLE_startx_length: {
dw_addr_t start = data.GetULEB128(offset_ptr);
dw_addr_t length = data.GetULEB128(offset_ptr);
rangeList.push_back({DW_RLE_startx_length, start, length});
break;
}
default:
lldbassert(0 && "unknown range list entry encoding");
error = true;
}
}
return false;
}
static uint64_t ReadAddressFromDebugAddrSection(const DWARFUnit *cu,
uint32_t index) {
uint32_t index_size = cu->GetAddressByteSize();
dw_offset_t addr_base = cu->GetAddrBase();
lldb::offset_t offset = addr_base + index * index_size;
return cu->GetSymbolFileDWARF()
.GetDWARFContext()
.getOrLoadAddrData()
.GetMaxU64(&offset, index_size);
}
bool DWARFDebugRngLists::FindRanges(const DWARFUnit *cu,
dw_offset_t debug_ranges_offset,
DWARFRangeList &range_list) const {
range_list.Clear();
dw_addr_t debug_ranges_address = cu->GetRangesBase() + debug_ranges_offset;
auto pos = m_range_map.find(debug_ranges_address);
if (pos != m_range_map.end()) {
dw_addr_t BaseAddr = cu->GetBaseAddress();
for (const RngListEntry &E : pos->second) {
switch (E.encoding) {
case DW_RLE_start_length:
range_list.Append(DWARFRangeList::Entry(E.value0, E.value1));
break;
case DW_RLE_base_address:
BaseAddr = E.value0;
break;
case DW_RLE_start_end:
range_list.Append(DWARFRangeList::Entry(E.value0, E.value1 - E.value0));
break;
case DW_RLE_offset_pair:
range_list.Append(
DWARFRangeList::Entry(BaseAddr + E.value0, E.value1 - E.value0));
break;
case DW_RLE_base_addressx: {
BaseAddr = ReadAddressFromDebugAddrSection(cu, E.value0);
break;
}
case DW_RLE_startx_endx: {
dw_addr_t start = ReadAddressFromDebugAddrSection(cu, E.value0);
dw_addr_t end = ReadAddressFromDebugAddrSection(cu, E.value1);
range_list.Append(DWARFRangeList::Entry(start, end - start));
break;
}
case DW_RLE_startx_length: {
dw_addr_t start = ReadAddressFromDebugAddrSection(cu, E.value0);
range_list.Append(DWARFRangeList::Entry(start, E.value1));
break;
}
default:
llvm_unreachable("unexpected encoding");
}
}
return true;
}
return false;
}
void DWARFDebugRngLists::Extract(DWARFContext &context) {
const DWARFDataExtractor &data = context.getOrLoadRngListsData();
lldb::offset_t offset = 0;
uint64_t length = data.GetU32(&offset);
// FIXME: Handle DWARF64.
lldb::offset_t end = offset + length;
// Check version.
if (data.GetU16(&offset) < 5)
return;
uint8_t addrSize = data.GetU8(&offset);
// We do not support non-zero segment selector size.
if (data.GetU8(&offset) != 0) {
lldbassert(0 && "not implemented");
return;
}
uint32_t offsetsAmount = data.GetU32(&offset);
for (uint32_t i = 0; i < offsetsAmount; ++i)
Offsets.push_back(data.GetMaxU64(&offset, 4));
lldb::offset_t listOffset = offset;
std::vector<RngListEntry> rangeList;
while (offset < end && ExtractRangeList(data, addrSize, &offset, rangeList)) {
m_range_map[listOffset] = rangeList;
listOffset = offset;
}
}
uint64_t DWARFDebugRngLists::GetOffset(size_t Index) const {
return Offsets[Index];
}
|