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// Copyright 2016 Google Inc. All Rights Reserved.
//
// 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.
#include <assert.h>
#include <stdio.h>
#include <algorithm>
#include <filesystem>
#include <initializer_list>
#include <iostream>
#include <limits>
#include <memory>
#include <stack>
#include <string_view>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include "absl/base/attributes.h"
#include "absl/base/macros.h"
#include "absl/strings/substitute.h"
#include "absl/types/optional.h"
#include "bloaty.h"
#include "bloaty.pb.h"
#include "dwarf_constants.h"
#include "util.h"
#include "dwarf/attr.h"
#include "dwarf/dwarf_util.h"
#include "dwarf/line_info.h"
using namespace dwarf2reader;
using std::string_view;
namespace bloaty {
extern int verbose_level;
namespace dwarf {
// AddressRanges ///////////////////////////////////////////////////////////////
// Code for reading address ranges out of .debug_aranges.
class AddressRanges {
public:
AddressRanges(string_view data) : section_(data), next_unit_(data) {}
// Offset into .debug_info for the current compilation unit.
uint64_t debug_info_offset() { return debug_info_offset_; }
// Address and length for this range.
uint64_t address() { return address_; }
uint64_t length() { return length_; }
// The range of the file where this data occurs.
string_view data() { return data_; }
// Advance to the next range. The values will be available in address() and
// length(). Returns false when the end of this compilation unit is hit.
// Must call this once before reading the first range.
bool NextRange();
// Advance to the next compilation unit. The unit offset will be available in
// debug_info_offset(). Must call this once before reading the first unit.
bool NextUnit();
uint8_t address_size() const { return sizes_.address_size(); }
private:
CompilationUnitSizes sizes_;
string_view data_;
string_view section_;
string_view unit_remaining_;
string_view next_unit_;
uint64_t debug_info_offset_;
uint64_t address_;
uint64_t length_;
};
bool AddressRanges::NextRange() {
if (unit_remaining_.empty()) {
return false;
}
const char* start = unit_remaining_.data();
address_ = sizes_.ReadAddress(&unit_remaining_);
length_ = sizes_.ReadAddress(&unit_remaining_);
data_ = string_view(start, unit_remaining_.data() - start);
return true;
}
bool AddressRanges::NextUnit() {
if (next_unit_.empty()) {
return false;
}
unit_remaining_ = sizes_.ReadInitialLength(&next_unit_);
sizes_.ReadDWARFVersion(&unit_remaining_);
if (sizes_.dwarf_version() > 4) {
THROW("DWARF data is too new for us");
}
debug_info_offset_ = sizes_.ReadDWARFOffset(&unit_remaining_);
uint8_t segment_size;
sizes_.SetAddressSize(ReadFixed<uint8_t>(&unit_remaining_));
segment_size = ReadFixed<uint8_t>(&unit_remaining_);
if (segment_size) {
THROW("we don't know how to handle segmented addresses.");
}
size_t ofs = unit_remaining_.data() - section_.data();
size_t aligned_ofs = AlignUp(ofs, sizes_.address_size() * 2);
SkipBytes(aligned_ofs - ofs, &unit_remaining_);
return true;
}
// LocationList ////////////////////////////////////////////////////////////////
// Code for reading entries out of a location list.
// For the moment we only care about finding the bounds of a list given its
// offset, so we don't actually vend any of the data.
class LocationList {
public:
LocationList(CompilationUnitSizes sizes, string_view data)
: sizes_(sizes), remaining_(data) {}
const char* read_offset() const { return remaining_.data(); }
bool NextEntry();
private:
CompilationUnitSizes sizes_;
string_view remaining_;
};
bool LocationList::NextEntry() {
uint64_t start, end;
start = sizes_.ReadAddress(&remaining_);
end = sizes_.ReadAddress(&remaining_);
if (start == 0 && end == 0) {
return false;
} else if (start == UINT64_MAX ||
(start == UINT32_MAX && sizes_.address_size() == 4)) {
// Base address selection, nothing more to do.
} else {
// Need to skip the location description.
uint16_t length = ReadFixed<uint16_t>(&remaining_);
SkipBytes(length, &remaining_);
}
return true;
}
string_view GetLocationListRange(CompilationUnitSizes sizes,
string_view available) {
LocationList list(sizes, available);
while (list.NextEntry()) {}
return available.substr(0, list.read_offset() - available.data());
}
// RangeList ///////////////////////////////////////////////////////////////////
void ReadRangeList(const CU& cu, uint64_t low_pc, string_view name,
RangeSink* sink, string_view* data) {
std::string name_str(name);
uint64_t max_address = cu.unit_sizes().MaxAddress();
while (true) {
uint64_t start, end;
start = cu.unit_sizes().ReadAddress(data);
end = cu.unit_sizes().ReadAddress(data);
if (start == 0 && end == 0) {
return;
} else if (start == max_address) {
low_pc = end;
} else if (end < start) {
WARN("DWARF end < start for $0: $1 < $2", name_str, end, start);
} else {
uint64_t size = end - start;
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelist", low_pc + start, size,
name_str);
}
}
}
string_view* File::GetFieldByName(string_view name) {
if (name == "aranges") {
return &debug_aranges;
} else if (name == "addr") {
return &debug_addr;
} else if (name == "str") {
return &debug_str;
} else if (name == "str_offsets" || name == "str_offs") {
// Mach-O section names are limited to 16 characters. The full name
// "__debug_str_offsets" gets truncated to "__debug_str_offs".
// After removing the "__debug_" prefix, we get "str_offs" instead of
// "str_offsets". This is the only DWARF section exceeds the limit.
return &debug_str_offsets;
} else if (name == "line_str") {
return &debug_line_str;
} else if (name == "info") {
return &debug_info;
} else if (name == "types") {
return &debug_types;
} else if (name == "abbrev") {
return &debug_abbrev;
} else if (name == "line") {
return &debug_line;
} else if (name == "loc") {
return &debug_loc;
} else if (name == "pubnames") {
return &debug_pubnames;
} else if (name == "pubtypes") {
return &debug_pubtypes;
} else if (name == "ranges") {
return &debug_ranges;
} else if (name == "rnglists") {
return &debug_rnglists;
} else {
return nullptr;
}
}
} // namespace dwarf
// Bloaty DWARF Data Sources ///////////////////////////////////////////////////
// The DWARF .debug_aranges section should, in theory, give us exactly the
// information we need to map file ranges in linked binaries to compilation
// units from where that code came. However, .debug_aranges is often incomplete
// or missing completely, so we use it as just one of several data sources for
// the "compileunits" data source.
static bool ReadDWARFAddressRanges(const dwarf::File& file, RangeSink* sink) {
// Maps compilation unit offset -> source filename
// Lazily initialized.
class FilenameMap {
public:
FilenameMap(const dwarf::File& file)
: info_reader_(file),
missing_("[DWARF is missing filename]") {}
std::string GetFilename(uint64_t compilation_unit_offset) {
auto& name = map_[compilation_unit_offset];
if (name.empty()) {
name = LookupFilename(compilation_unit_offset);
}
return name;
}
private:
bool ReadName(std::string* name, uint64_t offset) {
auto sec = dwarf::InfoReader::Section::kDebugInfo;
dwarf::CUIter iter = info_reader_.GetCUIter(sec, offset);
dwarf::CU cu;
if (!iter.NextCU(info_reader_, &cu)) {
return false;
}
*name = cu.unit_name();
return true;
}
std::string LookupFilename(uint64_t compilation_unit_offset) {
std::string name;
if (ReadName(&name, compilation_unit_offset)) {
return name;
} else {
return missing_;
}
}
dwarf::InfoReader info_reader_;
std::unordered_map<uint64_t, std::string> map_;
std::string missing_;
} map(file);
dwarf::AddressRanges ranges(file.debug_aranges);
while (ranges.NextUnit()) {
std::string filename = map.GetFilename(ranges.debug_info_offset());
while (ranges.NextRange()) {
if (dwarf::IsValidDwarfAddress(ranges.address(), ranges.address_size())) {
sink->AddVMRangeIgnoreDuplicate("dwarf_aranges", ranges.address(),
ranges.length(), filename);
}
sink->AddFileRange("dwarf_aranges_data", filename, ranges.data());
}
}
return true;
}
struct GeneralDIE {
absl::optional<string_view> name;
absl::optional<string_view> location_string;
absl::optional<uint64_t> location_uint64;
absl::optional<uint64_t> low_pc;
absl::optional<uint64_t> high_pc_addr;
absl::optional<uint64_t> high_pc_size;
absl::optional<uint64_t> stmt_list;
absl::optional<uint64_t> rnglistx;
absl::optional<uint64_t> ranges;
absl::optional<uint64_t> start_scope;
bool declaration = false;
};
void ReadGeneralDIEAttr(uint16_t tag, dwarf::AttrValue val, const dwarf::CU& cu,
GeneralDIE* die) {
switch (tag) {
case DW_AT_name:
if (val.IsString()) {
die->name = val.GetString(cu);
}
break;
case DW_AT_declaration:
if (auto uint = val.ToUint(cu)) {
die->declaration = *uint;
}
break;
case DW_AT_location:
if (val.IsString()) {
die->location_string = val.GetString(cu);
} else if (val.form() == DW_FORM_sec_offset) {
die->location_uint64 = val.GetUint(cu);
}
break;
case DW_AT_low_pc:
if (auto uint = val.ToUint(cu)) {
die->low_pc = *uint;
}
break;
case DW_AT_high_pc:
switch (val.form()) {
case DW_FORM_addr:
case DW_FORM_addrx:
case DW_FORM_addrx1:
case DW_FORM_addrx2:
case DW_FORM_addrx3:
case DW_FORM_addrx4:
// high_pc is absolute.
die->high_pc_addr = val.GetUint(cu);
break;
case DW_FORM_data1:
case DW_FORM_data2:
case DW_FORM_data4:
case DW_FORM_data8:
// high_pc is a size.
die->high_pc_size = val.ToUint(cu);
break;
default:
if (verbose_level > 0) {
fprintf(stderr, "Unexpected form for high_pc: %d\n", val.form());
}
break;
}
break;
case DW_AT_stmt_list:
if (auto uint = val.ToUint(cu)) {
die->stmt_list = *uint;
}
break;
case DW_AT_ranges:
if (auto uint = val.ToUint(cu)) {
if (val.form() == DW_FORM_rnglistx) {
die->rnglistx = *uint;
} else {
die->ranges = *uint;
}
}
break;
case DW_AT_start_scope:
if (auto uint = val.ToUint(cu)) {
die->start_scope = *uint;
}
break;
}
}
uint64_t TryReadPcPair(const dwarf::CU& cu, const GeneralDIE& die,
RangeSink* sink) {
uint64_t addr;
uint64_t size;
if (!die.low_pc) return 0;
addr = *die.low_pc;
if (die.high_pc_addr) {
if (*die.high_pc_addr < addr) {
WARN("DWARF high_pc < low_pc for $0: $1 < $2", cu.unit_name(),
*die.high_pc_addr, addr);
return 0;
}
size = *die.high_pc_addr - addr;
} else if (die.high_pc_size) {
size = *die.high_pc_size;
} else{
return 0;
}
sink->AddVMRangeIgnoreDuplicate("dwarf_pcpair", addr, size, cu.unit_name());
return addr;
}
// To view DIEs for a given file, try:
// readelf --debug-dump=info foo.bin
void AddDIE(const dwarf::CU& cu, const GeneralDIE& die,
const DualMap& symbol_map, RangeSink* sink) {
uint64_t low_pc = TryReadPcPair(cu, die, sink);
// Sometimes the DIE has a "location", which gives the location as an address.
// This parses a very small subset of the overall DWARF expression grammar.
if (die.location_string) {
string_view location = *die.location_string;
if (location.size() == cu.unit_sizes().address_size() + 1 &&
location[0] == DW_OP_addr) {
location.remove_prefix(1);
uint64_t addr;
// TODO(haberman): endian?
if (cu.unit_sizes().address_size() == 4) {
addr = ReadFixed<uint32_t>(&location);
} else if (cu.unit_sizes().address_size() == 8) {
addr = ReadFixed<uint64_t>(&location);
} else {
BLOATY_UNREACHABLE();
}
// Unfortunately the location doesn't include a size, so we look that part
// up in the symbol map.
uint64_t size;
if (symbol_map.vm_map.TryGetSize(addr, &size)) {
sink->AddVMRangeIgnoreDuplicate("dwarf_location", addr, size,
cu.unit_name());
} else {
if (verbose_level > 0) {
fprintf(stderr,
"bloaty: warning: couldn't find DWARF location in symbol "
"table, address: %" PRIx64 ", name: %s\n",
addr, cu.unit_name().c_str());
}
}
}
}
// Sometimes a location is given as an offset into debug_loc.
if (die.location_uint64 && cu.unit_sizes().dwarf_version() < 5) {
uint64_t location = *die.location_uint64;;
if (location < cu.dwarf().debug_loc.size()) {
std::string_view loc_range = cu.dwarf().debug_loc.substr(location);
loc_range = GetLocationListRange(cu.unit_sizes(), loc_range);
sink->AddFileRange("dwarf_locrange", cu.unit_name(), loc_range);
} else if (verbose_level > 0) {
fprintf(stderr,
"bloaty: warning: DWARF location out of range, location=%" PRIx64
"\n",
location);
}
} else if (cu.unit_sizes().dwarf_version() >= 5) {
// DWARF 5 range list is the same information as "ranges" but in a different
// format.
std::string_view data;
if (die.rnglistx) {
// Handle DW_FORM_rnglistx (indexed form)
uint64_t range_list = *die.rnglistx;
size_t offset_size = cu.unit_sizes().dwarf64() ? 8 : 4;
string_view offset_data =
StrictSubstr(cu.dwarf().debug_rnglists,
cu.range_lists_base() + (range_list * offset_size));
uint64_t offset = cu.unit_sizes().ReadDWARFOffset(&offset_data);
data = StrictSubstr(
cu.dwarf().debug_rnglists, cu.range_lists_base() + offset);
} else if (die.ranges) {
// Handle DW_FORM_sec_offset (direct offset)
uint64_t ranges_offset = *die.ranges;
data = StrictSubstr(cu.dwarf().debug_rnglists, ranges_offset);
} else {
// No valid range list found, return early
return;
}
const char* start = data.data();
bool done = false;
uint64_t base_address = cu.addr_base();
while (!done) {
switch (ReadFixed<uint8_t>(&data)) {
case DW_RLE_end_of_list:
done = true;
break;
case DW_RLE_base_addressx:
base_address =
ReadIndirectAddress(cu, dwarf::ReadLEB128<uint64_t>(&data));
break;
case DW_
8
RLE_star
10BC8
tx_endx: {
uint64_t start =
ReadIndirectAddress(cu, dwarf::ReadLEB128<uint64_t>(&data));
uint64_t end =
ReadIndirectAddress(cu, dwarf::ReadLEB128<uint64_t>(&data));
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelst", start, end - start,
cu.unit_name());
break;
}
case DW_RLE_startx_length: {
uint64_t start =
ReadIndirectAddress(cu, dwarf::ReadLEB128<uint64_t>(&data));
uint64_t length = dwarf::ReadLEB128<uint64_t>(&data);
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelst", start, length,
cu.unit_name());
break;
}
case DW_RLE_offset_pair: {
uint64_t start = dwarf::ReadLEB128<uint64_t>(&data) + base_address;
uint64_t end = dwarf::ReadLEB128<uint64_t>(&data) + base_address;
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelst", start, end - start,
cu.unit_name());
break;
}
case DW_RLE_base_address: {
base_address = cu.unit_sizes().ReadAddress(&data);
break;
}
case DW_RLE_start_end: {
uint64_t start = cu.unit_sizes().ReadAddress(&data);
uint64_t end = cu.unit_sizes().ReadAddress(&data);
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelst", start, end - start,
cu.unit_name());
break;
}
case DW_RLE_start_length: {
uint64_t start = cu.unit_sizes().ReadAddress(&data);
uint64_t len = dwarf::ReadLEB128<uint64_t>(&data);
sink->AddVMRangeIgnoreDuplicate("dwarf_rangelst", start, len,
cu.unit_name());
break;
}
}
}
string_view all(start, data.data() - start);
sink->AddFileRange("dwarf_rangelst_addrs", cu.unit_name(), all);
} else {
uint64_t ranges_offset = UINT64_MAX;
// There are two different attributes that sometimes contain an offset into
// debug_ranges.
if (die.ranges) {
ranges_offset = *die.ranges;
} else if (die.start_scope) {
ranges_offset = *die.start_scope;
}
if (ranges_offset != UINT64_MAX) {
if (ranges_offset < cu.dwarf().debug_ranges.size()) {
std::string_view data = cu.dwarf().debug_ranges.substr(ranges_offset);
const char* start = data.data();
ReadRangeList(cu, low_pc, cu.unit_name(), sink, &data);
string_view all(start, data.data() - start);
sink->AddFileRange("dwarf_debugrange", cu.unit_name(), all);
} else if (verbose_level > 0) {
fprintf(stderr,
"bloaty: warning: DWARF debug range out of range, "
"ranges_offset=%" PRIx64 "\n",
ranges_offset);
}
}
}
}
static void ReadDWARFPubNames(dwarf::InfoReader& reader, string_view section,
RangeSink* sink) {
string_view remaining = section;
while (remaining.size() > 0) {
dwarf::CompilationUnitSizes sizes;
string_view full_unit = remaining;
string_view unit = sizes.ReadInitialLength(&remaining);
full_unit =
full_unit.substr(0, unit.size() + (unit.data() - full_unit.data()));
sizes.ReadDWARFVersion(&unit);
uint64_t debug_info_offset = sizes.ReadDWARFOffset(&unit);
dwarf::CUIter iter = reader.GetCUIter(
dwarf::InfoReader::Section::kDebugInfo, debug_info_offset);
dwarf::CU cu;
if (iter.NextCU(reader, &cu) && !cu.unit_name().empty()) {
sink->AddFileRange("dwarf_pubnames", cu.unit_name(), full_unit);
}
}
}
static void ReadDWARFStmtListRange(const dwarf::CU& cu, uint64_t offset,
RangeSink* sink) {
string_view data = cu.dwarf().debug_line;
SkipBytes(offset, &data);
string_view data_with_length = data;
dwarf::CompilationUnitSizes sizes;
data = sizes.ReadInitialLength(&data);
data = data_with_length.substr(
0, data.size() + (data.data() - data_with_length.data()));
sink->AddFileRange("dwarf_stmtlistrange", cu.unit_name(), data);
}
struct DwoFilePointer {
std::string comp_dir;
std::string dwo_name;
};
static std::string ConstructDwoPath(const DwoFilePointer& dwo_info) {
if (dwo_info.dwo_name.empty()) {
return "";
}
std::filesystem::path dwo_path(dwo_info.dwo_name);
if (dwo_path.is_absolute()) {
return dwo_info.dwo_name;
}
std::filesystem::path result = std::filesystem::path(dwo_info.comp_dir) / dwo_info.dwo_name;
return result.string();
}
// The DWARF debug info can help us get compileunits info. DIEs for compilation
// units, functions, and global variables often have attributes that will
// resolve to addresses.
static void ReadDWARFDebugInfo(dwarf::InfoReader& reader,
dwarf::InfoReader::Section section,
const DualMap& symbol_map, RangeSink* sink) {
dwarf::CUIter iter = reader.GetCUIter(section);
dwarf::CU cu;
cu.SetIndirectStringCallback([sink, &cu](string_view str) {
sink->AddFileRange("dwarf_strp", cu.unit_name(), str);
});
while (iter.NextCU(reader, &cu)) {
dwarf::DIEReader die_reader = cu.GetDIEReader();
GeneralDIE compileunit_die;
DwoFilePointer dwo_info;
auto* abbrev = die_reader.ReadCode(cu);
if (!abbrev) {
continue;
}
die_reader.ReadAttributes(
cu, abbrev,
[&](uint16_t tag, dwarf::AttrValue value) {
ReadGeneralDIEAttr(tag, value, cu, &compileunit_die);
switch (tag) {
case DW_AT_comp_dir:
if (value.IsString()) {
dwo_info.comp_dir = value.GetString(cu);
}
break;
case DW_AT_GNU_dwo_name:
if (value.IsString()) {
dwo_info.dwo_name = value.GetString(cu);
}
break;
}
});
std::string dwo_path = ConstructDwoPath(dwo_info);
if (!dwo_path.empty()) {
auto file = MmapInputFileFactory().OpenFile(dwo_path);
dwarf::File dwo_dwarf;
cu.dwarf().open(*file, &dwo_dwarf, sink);
ReadDWARFCompileUnits(dwo_dwarf, symbol_map, &cu, sink);
}
if (cu.unit_name().empty()) {
continue;
}
sink->AddFileRange("dwarf_debuginfo", cu.unit_name(), cu.entire_unit());
AddDIE(cu, compileunit_die, symbol_map, sink);
if (compileunit_die.stmt_list) {
ReadDWARFStmtListRange(cu, *compileunit_die.stmt_list, sink);
}
sink->AddFileRange("dwarf_abbrev", cu.unit_name(), cu.unit_abbrev().abbrev_data());
while (auto abbrev = die_reader.ReadCode(cu)) {
GeneralDIE die;
die_reader.ReadAttributes(
cu, abbrev, [&cu, &die](uint16_t tag, dwarf::AttrValue value) {
ReadGeneralDIEAttr(tag, value, cu, &die);
});
// low_pc == 0 is a signal that this routine was stripped out of the
// final binary. Also any declaration should be skipped.
if ((die.low_pc && !cu.IsValidDwarfAddress(*die.low_pc)) ||
die.declaration) {
die_reader.SkipChildren(cu, abbrev);
} else {
AddDIE(cu, die, symbol_map, sink);
}
}
}
}
void ReadDWARFCompileUnits(const dwarf::File& file, const DualMap& symbol_map,
const dwarf::CU* skeleton, RangeSink* sink) {
if (!file.debug_info.size()) {
THROW("missing debug info");
}
if (file.debug_aranges.size()) {
ReadDWARFAddressRanges(file, sink);
}
// Share a reader to avoid re-parsing debug abbreviations.
dwarf::InfoReader reader(file, skeleton);
ReadDWARFDebugInfo(reader, dwarf::InfoReader::Section::kDebugInfo, symbol_map,
sink);
ReadDWARFDebugInfo(reader, dwarf::InfoReader::Section::kDebugTypes,
symbol_map, sink);
ReadDWARFPubNames(reader, file.debug_pubnames, sink);
ReadDWARFPubNames(reader, file.debug_pubtypes, sink);
}
static std::string LineInfoKey(const std::string& file, uint32_t line,
bool include_line) {
if (include_line) {
return file + ":" + std::to_string(line);
} else {
return file;
}
}
static void ReadDWARFStmtList(bool include_line,
dwarf::LineInfoReader* line_info_reader,
RangeSink* sink) {
uint64_t span_startaddr = 0;
std::string last_source;
while (line_info_reader->ReadLineInfo()) {
const auto& line_info = line_info_reader->lineinfo();
auto addr = line_info.address;
auto number = line_info.line;
auto name =
line_info.end_sequence
? last_source
: LineInfoKey(line_info_reader->GetExpandedFilename(line_info.file),
number, include_line);
if (!span_startaddr) {
span_startaddr = addr;
} else if (line_info.end_sequence ||
(!last_source.empty() && name != last_source)) {
sink->AddVMRange("dwarf_stmtlist", span_startaddr, addr - span_startaddr,
last_source);
if (line_info.end_sequence) {
span_startaddr = 0;
} else {
span_startaddr = addr;
}
}
last_source = name;
}
}
void ReadDWARFInlines(const dwarf::File& file, RangeSink* sink,
bool include_line) {
if (!file.debug_info.size() || !file.debug_line.size()) {
THROW("no debug info");
}
dwarf::InfoReader reader(file);
dwarf::CUIter iter = reader.GetCUIter(dwarf::InfoReader::Section::kDebugInfo);
dwarf::CU cu;
dwarf::LineInfoReader line_info_reader(file);
while (iter.NextCU(reader, &cu)) {
dwarf::DIEReader die_reader = cu.GetDIEReader();
while (auto abbrev = die_reader.ReadCode(cu)) {
absl::optional<uint64_t> stmt_list;
die_reader.ReadAttributes(cu, abbrev,
[&](uint16_t tag, dwarf::AttrValue val) {
if (tag == DW_AT_stmt_list) {
stmt_list = val.ToUint(cu);
}});
if (stmt_list) {
line_info_reader.SeekToOffset(*stmt_list, cu.unit_sizes().address_size());
ReadDWARFStmtList(include_line, &line_info_reader, sink);
}
break; // only root-level unit entries have DW_AT_stmt_list attributes.
}
}
}
} // namespace bloaty