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llvm-mirror/lib/DebugInfo/DWARF/DWARFUnit.cpp
George Rimar 0219cd8ab5 [DWARF] - Use DWARFAddressRange struct instead of uint64_t pair for DWARFAddressRangesVector.
Recommit of r303159 "[DWARF] - Use DWARFAddressRange struct instead of uint64_t pair for DWARFAddressRangesVector"
All places were shitched to use DWARFAddressRange now.

Suggested during review of D33184.

llvm-svn: 303163
2017-05-16 12:30:59 +00:00

453 lines
15 KiB
C++

//===-- DWARFUnit.cpp -----------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Path.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <vector>
using namespace llvm;
using namespace dwarf;
void DWARFUnitSectionBase::parse(DWARFContext &C, const DWARFSection &Section) {
parseImpl(C, Section, C.getDebugAbbrev(), &C.getRangeSection(),
C.getStringSection(), StringRef(), C.getAddrSection(),
C.getLineSection().Data, C.isLittleEndian(), false);
}
void DWARFUnitSectionBase::parseDWO(DWARFContext &C,
const DWARFSection &DWOSection,
DWARFUnitIndex *Index) {
parseImpl(C, DWOSection, C.getDebugAbbrevDWO(), &C.getRangeDWOSection(),
C.getStringDWOSection(), C.getStringOffsetDWOSection(),
C.getAddrSection(), C.getLineDWOSection().Data, C.isLittleEndian(),
true);
}
DWARFUnit::DWARFUnit(DWARFContext &DC, const DWARFSection &Section,
const DWARFDebugAbbrev *DA, const DWARFSection *RS,
StringRef SS, StringRef SOS, StringRef AOS, StringRef LS,
bool LE, bool IsDWO,
const DWARFUnitSectionBase &UnitSection,
const DWARFUnitIndex::Entry *IndexEntry)
: Context(DC), InfoSection(Section), Abbrev(DA), RangeSection(RS),
LineSection(LS), StringSection(SS), StringOffsetSection([&]() {
if (IndexEntry)
if (const auto *C = IndexEntry->getOffset(DW_SECT_STR_OFFSETS))
return SOS.slice(C->Offset, C->Offset + C->Length);
return SOS;
}()),
AddrOffsetSection(AOS), isLittleEndian(LE), isDWO(IsDWO),
UnitSection(UnitSection), IndexEntry(IndexEntry) {
clear();
}
DWARFUnit::~DWARFUnit() = default;
bool DWARFUnit::getAddrOffsetSectionItem(uint32_t Index,
uint64_t &Result) const {
uint32_t Offset = AddrOffsetSectionBase + Index * AddrSize;
if (AddrOffsetSection.size() < Offset + AddrSize)
return false;
DataExtractor DA(AddrOffsetSection, isLittleEndian, AddrSize);
Result = DA.getAddress(&Offset);
return true;
}
bool DWARFUnit::getStringOffsetSectionItem(uint32_t Index,
uint32_t &Result) const {
// FIXME: string offset section entries are 8-byte for DWARF64.
const uint32_t ItemSize = 4;
uint32_t Offset = Index * ItemSize;
if (StringOffsetSection.size() < Offset + ItemSize)
return false;
DataExtractor DA(StringOffsetSection, isLittleEndian, 0);
Result = DA.getU32(&Offset);
return true;
}
bool DWARFUnit::extractImpl(DataExtractor debug_info, uint32_t *offset_ptr) {
Length = debug_info.getU32(offset_ptr);
Version = debug_info.getU16(offset_ptr);
uint64_t AbbrOffset;
if (Version >= 5) {
UnitType = debug_info.getU8(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
AbbrOffset = debug_info.getU32(offset_ptr);
} else {
AbbrOffset = debug_info.getU32(offset_ptr);
AddrSize = debug_info.getU8(offset_ptr);
}
if (IndexEntry) {
if (AbbrOffset)
return false;
auto *UnitContrib = IndexEntry->getOffset();
if (!UnitContrib || UnitContrib->Length != (Length + 4))
return false;
auto *AbbrEntry = IndexEntry->getOffset(DW_SECT_ABBREV);
if (!AbbrEntry)
return false;
AbbrOffset = AbbrEntry->Offset;
}
bool LengthOK = debug_info.isValidOffset(getNextUnitOffset() - 1);
bool VersionOK = DWARFContext::isSupportedVersion(Version);
bool AddrSizeOK = AddrSize == 4 || AddrSize == 8;
if (!LengthOK || !VersionOK || !AddrSizeOK)
return false;
Abbrevs = Abbrev->getAbbreviationDeclarationSet(AbbrOffset);
return Abbrevs != nullptr;
}
bool DWARFUnit::extract(DataExtractor debug_info, uint32_t *offset_ptr) {
clear();
Offset = *offset_ptr;
if (debug_info.isValidOffset(*offset_ptr)) {
if (extractImpl(debug_info, offset_ptr))
return true;
// reset the offset to where we tried to parse from if anything went wrong
*offset_ptr = Offset;
}
return false;
}
bool DWARFUnit::extractRangeList(uint32_t RangeListOffset,
DWARFDebugRangeList &RangeList) const {
// Require that compile unit is extracted.
assert(!DieArray.empty());
DataExtractor RangesData(RangeSection->Data, isLittleEndian, AddrSize);
uint32_t ActualRangeListOffset = RangeSectionBase + RangeListOffset;
return RangeList.extract(RangesData, &ActualRangeListOffset,
RangeSection->Relocs);
}
void DWARFUnit::clear() {
Offset = 0;
Length = 0;
Version = 0;
Abbrevs = nullptr;
AddrSize = 0;
BaseAddr = 0;
RangeSectionBase = 0;
AddrOffsetSectionBase = 0;
clearDIEs(false);
DWO.reset();
}
const char *DWARFUnit::getCompilationDir() {
return dwarf::toString(getUnitDIE().find(DW_AT_comp_dir), nullptr);
}
Optional<uint64_t> DWARFUnit::getDWOId() {
return toUnsigned(getUnitDIE().find(DW_AT_GNU_dwo_id));
}
void DWARFUnit::extractDIEsToVector(
bool AppendCUDie, bool AppendNonCUDies,
std::vector<DWARFDebugInfoEntry> &Dies) const {
if (!AppendCUDie && !AppendNonCUDies)
return;
// Set the offset to that of the first DIE and calculate the start of the
// next compilation unit header.
uint32_t DIEOffset = Offset + getHeaderSize();
uint32_t NextCUOffset = getNextUnitOffset();
DWARFDebugInfoEntry DIE;
DataExtractor DebugInfoData = getDebugInfoExtractor();
uint32_t Depth = 0;
bool IsCUDie = true;
while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset,
Depth)) {
if (IsCUDie) {
if (AppendCUDie)
Dies.push_back(DIE);
if (!AppendNonCUDies)
break;
// The average bytes per DIE entry has been seen to be
// around 14-20 so let's pre-reserve the needed memory for
// our DIE entries accordingly.
Dies.reserve(Dies.size() + getDebugInfoSize() / 14);
IsCUDie = false;
} else {
Dies.push_back(DIE);
}
if (const DWARFAbbreviationDeclaration *AbbrDecl =
DIE.getAbbreviationDeclarationPtr()) {
// Normal DIE
if (AbbrDecl->hasChildren())
++Depth;
} else {
// NULL DIE.
if (Depth > 0)
--Depth;
if (Depth == 0)
break; // We are done with this compile unit!
}
}
// Give a little bit of info if we encounter corrupt DWARF (our offset
// should always terminate at or before the start of the next compilation
// unit header).
if (DIEOffset > NextCUOffset)
fprintf(stderr, "warning: DWARF compile unit extends beyond its "
"bounds cu 0x%8.8x at 0x%8.8x'\n", getOffset(), DIEOffset);
}
size_t DWARFUnit::extractDIEsIfNeeded(bool CUDieOnly) {
if ((CUDieOnly && !DieArray.empty()) ||
DieArray.size() > 1)
return 0; // Already parsed.
bool HasCUDie = !DieArray.empty();
extractDIEsToVector(!HasCUDie, !CUDieOnly, DieArray);
if (DieArray.empty())
return 0;
// If CU DIE was just parsed, copy several attribute values from it.
if (!HasCUDie) {
DWARFDie UnitDie = getUnitDIE();
auto BaseAddr = toAddress(UnitDie.find({DW_AT_low_pc, DW_AT_entry_pc}));
if (BaseAddr)
setBaseAddress(*BaseAddr);
AddrOffsetSectionBase = toSectionOffset(UnitDie.find(DW_AT_GNU_addr_base), 0);
RangeSectionBase = toSectionOffset(UnitDie.find(DW_AT_rnglists_base), 0);
// Don't fall back to DW_AT_GNU_ranges_base: it should be ignored for
// skeleton CU DIE, so that DWARF users not aware of it are not broken.
}
return DieArray.size();
}
DWARFUnit::DWOHolder::DWOHolder(StringRef DWOPath) {
auto Obj = object::ObjectFile::createObjectFile(DWOPath);
if (!Obj) {
// TODO: Actually report errors helpfully.
consumeError(Obj.takeError());
return;
}
DWOFile = std::move(Obj.get());
DWOContext.reset(
cast<DWARFContext>(new DWARFContextInMemory(*DWOFile.getBinary())));
if (DWOContext->getNumDWOCompileUnits() > 0)
DWOU = DWOContext->getDWOCompileUnitAtIndex(0);
}
bool DWARFUnit::parseDWO() {
if (isDWO)
return false;
if (DWO.get())
return false;
DWARFDie UnitDie = getUnitDIE();
if (!UnitDie)
return false;
auto DWOFileName = dwarf::toString(UnitDie.find(DW_AT_GNU_dwo_name));
if (!DWOFileName)
return false;
auto CompilationDir = dwarf::toString(UnitDie.find(DW_AT_comp_dir));
SmallString<16> AbsolutePath;
if (sys::path::is_relative(*DWOFileName) && CompilationDir &&
*CompilationDir) {
sys::path::append(AbsolutePath, *CompilationDir);
}
sys::path::append(AbsolutePath, *DWOFileName);
DWO = llvm::make_unique<DWOHolder>(AbsolutePath);
DWARFUnit *DWOCU = DWO->getUnit();
// Verify that compile unit in .dwo file is valid.
if (!DWOCU || DWOCU->getDWOId() != getDWOId()) {
DWO.reset();
return false;
}
// Share .debug_addr and .debug_ranges section with compile unit in .dwo
DWOCU->setAddrOffsetSection(AddrOffsetSection, AddrOffsetSectionBase);
auto DWORangesBase = UnitDie.getRangesBaseAttribute();
DWOCU->setRangesSection(RangeSection, DWORangesBase ? *DWORangesBase : 0);
return true;
}
void DWARFUnit::clearDIEs(bool KeepCUDie) {
if (DieArray.size() > (unsigned)KeepCUDie) {
// std::vectors never get any smaller when resized to a smaller size,
// or when clear() or erase() are called, the size will report that it
// is smaller, but the memory allocated remains intact (call capacity()
// to see this). So we need to create a temporary vector and swap the
// contents which will cause just the internal pointers to be swapped
// so that when temporary vector goes out of scope, it will destroy the
// contents.
std::vector<DWARFDebugInfoEntry> TmpArray;
DieArray.swap(TmpArray);
// Save at least the compile unit DIE
if (KeepCUDie)
DieArray.push_back(TmpArray.front());
}
}
void DWARFUnit::collectAddressRanges(DWARFAddressRangesVector &CURanges) {
DWARFDie UnitDie = getUnitDIE();
if (!UnitDie)
return;
// First, check if unit DIE describes address ranges for the whole unit.
const auto &CUDIERanges = UnitDie.getAddressRanges();
if (!CUDIERanges.empty()) {
CURanges.insert(CURanges.end(), CUDIERanges.begin(), CUDIERanges.end());
return;
}
// This function is usually called if there in no .debug_aranges section
// in order to produce a compile unit level set of address ranges that
// is accurate. If the DIEs weren't parsed, then we don't want all dies for
// all compile units to stay loaded when they weren't needed. So we can end
// up parsing the DWARF and then throwing them all away to keep memory usage
// down.
const bool ClearDIEs = extractDIEsIfNeeded(false) > 1;
getUnitDIE().collectChildrenAddressRanges(CURanges);
// Collect address ranges from DIEs in .dwo if necessary.
bool DWOCreated = parseDWO();
if (DWO.get())
DWO->getUnit()->collectAddressRanges(CURanges);
if (DWOCreated)
DWO.reset();
// Keep memory down by clearing DIEs if this generate function
// caused them to be parsed.
if (ClearDIEs)
clearDIEs(true);
}
void DWARFUnit::updateAddressDieMap(DWARFDie Die) {
if (Die.isSubroutineDIE()) {
for (const auto &R : Die.getAddressRanges()) {
// Ignore 0-sized ranges.
if (R.LowPC == R.HighPC)
continue;
auto B = AddrDieMap.upper_bound(R.LowPC);
if (B != AddrDieMap.begin() && R.LowPC < (--B)->second.first) {
// The range is a sub-range of existing ranges, we need to split the
// existing range.
if (R.HighPC < B->second.first)
AddrDieMap[R.HighPC] = B->second;
if (R.LowPC > B->first)
AddrDieMap[B->first].first = R.LowPC;
}
AddrDieMap[R.LowPC] = std::make_pair(R.HighPC, Die);
}
}
// Parent DIEs are added to the AddrDieMap prior to the Children DIEs to
// simplify the logic to update AddrDieMap. The child's range will always
// be equal or smaller than the parent's range. With this assumption, when
// adding one range into the map, it will at most split a range into 3
// sub-ranges.
for (DWARFDie Child = Die.getFirstChild(); Child; Child = Child.getSibling())
updateAddressDieMap(Child);
}
DWARFDie DWARFUnit::getSubroutineForAddress(uint64_t Address) {
extractDIEsIfNeeded(false);
if (AddrDieMap.empty())
updateAddressDieMap(getUnitDIE());
auto R = AddrDieMap.upper_bound(Address);
if (R == AddrDieMap.begin())
return DWARFDie();
// upper_bound's previous item contains Address.
--R;
if (Address >= R->second.first)
return DWARFDie();
return R->second.second;
}
void
DWARFUnit::getInlinedChainForAddress(uint64_t Address,
SmallVectorImpl<DWARFDie> &InlinedChain) {
assert(InlinedChain.empty());
// Try to look for subprogram DIEs in the DWO file.
parseDWO();
// First, find the subroutine that contains the given address (the leaf
// of inlined chain).
DWARFDie SubroutineDIE =
(DWO ? DWO->getUnit() : this)->getSubroutineForAddress(Address);
while (SubroutineDIE) {
if (SubroutineDIE.isSubroutineDIE())
InlinedChain.push_back(SubroutineDIE);
SubroutineDIE = SubroutineDIE.getParent();
}
}
const DWARFUnitIndex &llvm::getDWARFUnitIndex(DWARFContext &Context,
DWARFSectionKind Kind) {
if (Kind == DW_SECT_INFO)
return Context.getCUIndex();
assert(Kind == DW_SECT_TYPES);
return Context.getTUIndex();
}
DWARFDie DWARFUnit::getParent(const DWARFDebugInfoEntry *Die) {
if (!Die)
return DWARFDie();
const uint32_t Depth = Die->getDepth();
// Unit DIEs always have a depth of zero and never have parents.
if (Depth == 0)
return DWARFDie();
// Depth of 1 always means parent is the compile/type unit.
if (Depth == 1)
return getUnitDIE();
// Look for previous DIE with a depth that is one less than the Die's depth.
const uint32_t ParentDepth = Depth - 1;
for (uint32_t I = getDIEIndex(Die) - 1; I > 0; --I) {
if (DieArray[I].getDepth() == ParentDepth)
return DWARFDie(this, &DieArray[I]);
}
return DWARFDie();
}
DWARFDie DWARFUnit::getSibling(const DWARFDebugInfoEntry *Die) {
if (!Die)
return DWARFDie();
uint32_t Depth = Die->getDepth();
// Unit DIEs always have a depth of zero and never have siblings.
if (Depth == 0)
return DWARFDie();
// NULL DIEs don't have siblings.
if (Die->getAbbreviationDeclarationPtr() == nullptr)
return DWARFDie();
// Find the next DIE whose depth is the same as the Die's depth.
for (size_t I = getDIEIndex(Die) + 1, EndIdx = DieArray.size(); I < EndIdx;
++I) {
if (DieArray[I].getDepth() == Depth)
return DWARFDie(this, &DieArray[I]);
}
return DWARFDie();
}