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//===- DWARFDebugLoc.cpp --------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFExpression.h"
#include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cinttypes>
#include <cstdint>
using namespace llvm;
// When directly dumping the .debug_loc without a compile unit, we have to guess
// at the DWARF version. This only affects DW_OP_call_ref, which is a rare
// expression that LLVM doesn't produce. Guessing the wrong version means we
// won't be able to pretty print expressions in DWARF2 binaries produced by
// non-LLVM tools.
static void dumpExpression(raw_ostream &OS, ArrayRef<char> Data,
bool IsLittleEndian, unsigned AddressSize,
const MCRegisterInfo *MRI) {
DWARFDataExtractor Extractor(StringRef(Data.data(), Data.size()),
IsLittleEndian, AddressSize);
DWARFExpression(Extractor, dwarf::DWARF_VERSION, AddressSize).print(OS, MRI);
}
void DWARFDebugLoc::LocationList::dump(raw_ostream &OS, bool IsLittleEndian,
unsigned AddressSize,
const MCRegisterInfo *MRI,
uint64_t BaseAddress,
unsigned Indent) const {
for (const Entry &E : Entries) {
OS << '\n';
OS.indent(Indent);
OS << format("[0x%*.*" PRIx64 ", ", AddressSize * 2, AddressSize * 2,
BaseAddress + E.Begin);
OS << format(" 0x%*.*" PRIx64 ")", AddressSize * 2, AddressSize * 2,
BaseAddress + E.End);
OS << ": ";
dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
}
}
DWARFDebugLoc::LocationList const *
DWARFDebugLoc::getLocationListAtOffset(uint64_t Offset) const {
auto It = std::lower_bound(
Locations.begin(), Locations.end(), Offset,
[](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
if (It != Locations.end() && It->Offset == Offset)
return &(*It);
return nullptr;
}
void DWARFDebugLoc::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
Optional<uint64_t> Offset) const {
auto DumpLocationList = [&](const LocationList &L) {
OS << format("0x%8.8x: ", L.Offset);
L.dump(OS, IsLittleEndian, AddressSize, MRI, 0, 12);
OS << "\n\n";
};
if (Offset) {
if (auto *L = getLocationListAtOffset(*Offset))
DumpLocationList(*L);
return;
}
for (const LocationList &L : Locations) {
DumpLocationList(L);
}
}
Optional<DWARFDebugLoc::LocationList>
DWARFDebugLoc::parseOneLocationList(DWARFDataExtractor Data, unsigned *Offset) {
LocationList LL;
LL.Offset = *Offset;
// 2.6.2 Location Lists
// A location list entry consists of:
while (true) {
Entry E;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2 * Data.getAddressSize())) {
WithColor::error() << "location list overflows the debug_loc section.\n";
return None;
}
// 1. A beginning address offset. ...
E.Begin = Data.getRelocatedAddress(Offset);
// 2. An ending address offset. ...
E.End = Data.getRelocatedAddress(Offset);
// The end of any given location list is marked by an end of list entry,
// which consists of a 0 for the beginning address offset and a 0 for the
// ending address offset.
if (E.Begin == 0 && E.End == 0)
return LL;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2)) {
WithColor::error() << "location list overflows the debug_loc section.\n";
return None;
}
unsigned Bytes = Data.getU16(Offset);
if (!Data.isValidOffsetForDataOfSize(*Offset, Bytes)) {
WithColor::error() << "location list overflows the debug_loc section.\n";
return None;
}
// A single location description describing the location of the object...
StringRef str = Data.getData().substr(*Offset, Bytes);
*Offset += Bytes;
E.Loc.reserve(str.size());
std::copy(str.begin(), str.end(), std::back_inserter(E.Loc));
LL.Entries.push_back(std::move(E));
}
}
void DWARFDebugLoc::parse(const DWARFDataExtractor &data) {
IsLittleEndian = data.isLittleEndian();
AddressSize = data.getAddressSize();
uint32_t Offset = 0;
while (data.isValidOffset(Offset + data.getAddressSize() - 1)) {
if (auto LL = parseOneLocationList(data, &Offset))
Locations.push_back(std::move(*LL));
else
break;
}
if (data.isValidOffset(Offset))
WithColor::error() << "failed to consume entire .debug_loc section\n";
}
Optional<DWARFDebugLocDWO::LocationList>
DWARFDebugLocDWO::parseOneLocationList(DataExtractor Data, unsigned *Offset) {
LocationList LL;
LL.Offset = *Offset;
// dwarf::DW_LLE_end_of_list_entry is 0 and indicates the end of the list.
while (auto Kind =
static_cast<dwarf::LocationListEntry>(Data.getU8(Offset))) {
if (Kind != dwarf::DW_LLE_startx_length) {
WithColor::error() << "dumping support for LLE of kind " << (int)Kind
<< " not implemented\n";
return None;
}
Entry E;
E.Start = Data.getULEB128(Offset);
E.Length = Data.getU32(Offset);
unsigned Bytes = Data.getU16(Offset);
// A single location description describing the location of the object...
StringRef str = Data.getData().substr(*Offset, Bytes);
*Offset += Bytes;
E.Loc.resize(str.size());
std::copy(str.begin(), str.end(), E.Loc.begin());
LL.Entries.push_back(std::move(E));
}
return LL;
}
void DWARFDebugLocDWO::parse(DataExtractor data) {
IsLittleEndian = data.isLittleEndian();
AddressSize = data.getAddressSize();
uint32_t Offset = 0;
while (data.isValidOffset(Offset)) {
if (auto LL = parseOneLocationList(data, &Offset))
Locations.push_back(std::move(*LL));
else
return;
}
}
DWARFDebugLocDWO::LocationList const *
DWARFDebugLocDWO::getLocationListAtOffset(uint64_t Offset) const {
auto It = std::lower_bound(
Locations.begin(), Locations.end(), Offset,
[](const LocationList &L, uint64_t Offset) { return L.Offset < Offset; });
if (It != Locations.end() && It->Offset == Offset)
return &(*It);
return nullptr;
}
void DWARFDebugLocDWO::LocationList::dump(raw_ostream &OS, bool IsLittleEndian,
unsigned AddressSize,
const MCRegisterInfo *MRI,
unsigned Indent) const {
for (const Entry &E : Entries) {
OS << '\n';
OS.indent(Indent);
OS << "Addr idx " << E.Start << " (w/ length " << E.Length << "): ";
dumpExpression(OS, E.Loc, IsLittleEndian, AddressSize, MRI);
}
}
void DWARFDebugLocDWO::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
Optional<uint64_t> Offset) const {
auto DumpLocationList = [&](const LocationList &L) {
OS << format("0x%8.8x: ", L.Offset);
L.dump(OS, IsLittleEndian, AddressSize, MRI, /*Indent=*/12);
OS << "\n\n";
};
if (Offset) {
if (auto *L = getLocationListAtOffset(*Offset))
DumpLocationList(*L);
return;
}
for (const LocationList &L : Locations) {
DumpLocationList(L);
}
}
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