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clang-p2996/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
Greg Clayton c7695a8e45 Verify that all references point to actual DIEs in "llvm-dwarfdump --verify" 
LTO and other fancy linking previously led to DWARF that contained invalid references. We already validate that CU relative references fall into the CU, and the DW_FORM_ref_addr references fall inside the .debug_info section, but we didn't validate that the references pointed to correct DIE offsets. This new verification will ensure that all references refer to actual DIEs and not an offset in between.

This caught a bug in DWARFUnit::getDIEForOffset() where if you gave it any offset, it would match the DIE that mathes the offset _or_ the next DIE. This has been fixed.

Differential Revision: https://reviews.llvm.org/D32722

llvm-svn: 301971
2017-05-02 20:28:33 +00:00

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//===- DWARFContext.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/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
#include "llvm/DebugInfo/DWARF/DWARFSection.h"
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
#include "llvm/Object/Decompressor.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/RelocVisitor.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdint>
#include <map>
#include <set>
#include <string>
#include <utility>
#include <vector>
using namespace llvm;
using namespace dwarf;
using namespace object;
#define DEBUG_TYPE "dwarf"
typedef DWARFDebugLine::LineTable DWARFLineTable;
typedef DILineInfoSpecifier::FileLineInfoKind FileLineInfoKind;
typedef DILineInfoSpecifier::FunctionNameKind FunctionNameKind;
uint64_t llvm::getRelocatedValue(const DataExtractor &Data, uint32_t Size,
uint32_t *Off, const RelocAddrMap *Relocs) {
if (!Relocs)
return Data.getUnsigned(Off, Size);
RelocAddrMap::const_iterator AI = Relocs->find(*Off);
if (AI == Relocs->end())
return Data.getUnsigned(Off, Size);
return Data.getUnsigned(Off, Size) + AI->second.second;
}
static void dumpAccelSection(raw_ostream &OS, StringRef Name,
const DWARFSection& Section, StringRef StringSection,
bool LittleEndian) {
DataExtractor AccelSection(Section.Data, LittleEndian, 0);
DataExtractor StrData(StringSection, LittleEndian, 0);
OS << "\n." << Name << " contents:\n";
DWARFAcceleratorTable Accel(AccelSection, StrData, Section.Relocs);
if (!Accel.extract())
return;
Accel.dump(OS);
}
void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType, bool DumpEH,
bool SummarizeTypes) {
if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
OS << ".debug_abbrev contents:\n";
getDebugAbbrev()->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo)
if (const DWARFDebugAbbrev *D = getDebugAbbrevDWO()) {
OS << "\n.debug_abbrev.dwo contents:\n";
D->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Info) {
OS << "\n.debug_info contents:\n";
for (const auto &CU : compile_units())
CU->dump(OS);
}
if ((DumpType == DIDT_All || DumpType == DIDT_InfoDwo) &&
getNumDWOCompileUnits()) {
OS << "\n.debug_info.dwo contents:\n";
for (const auto &DWOCU : dwo_compile_units())
DWOCU->dump(OS);
}
if ((DumpType == DIDT_All || DumpType == DIDT_Types) && getNumTypeUnits()) {
OS << "\n.debug_types contents:\n";
for (const auto &TUS : type_unit_sections())
for (const auto &TU : TUS)
TU->dump(OS, SummarizeTypes);
}
if ((DumpType == DIDT_All || DumpType == DIDT_TypesDwo) &&
getNumDWOTypeUnits()) {
OS << "\n.debug_types.dwo contents:\n";
for (const auto &DWOTUS : dwo_type_unit_sections())
for (const auto &DWOTU : DWOTUS)
DWOTU->dump(OS, SummarizeTypes);
}
if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
OS << "\n.debug_loc contents:\n";
getDebugLoc()->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_LocDwo) {
OS << "\n.debug_loc.dwo contents:\n";
getDebugLocDWO()->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
OS << "\n.debug_frame contents:\n";
getDebugFrame()->dump(OS);
if (DumpEH) {
OS << "\n.eh_frame contents:\n";
getEHFrame()->dump(OS);
}
}
if (DumpType == DIDT_All || DumpType == DIDT_Macro) {
OS << "\n.debug_macinfo contents:\n";
getDebugMacro()->dump(OS);
}
uint32_t offset = 0;
if (DumpType == DIDT_All || DumpType == DIDT_Aranges) {
OS << "\n.debug_aranges contents:\n";
DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
DWARFDebugArangeSet set;
while (set.extract(arangesData, &offset))
set.dump(OS);
}
uint8_t savedAddressByteSize = 0;
if (DumpType == DIDT_All || DumpType == DIDT_Line) {
OS << "\n.debug_line contents:\n";
for (const auto &CU : compile_units()) {
savedAddressByteSize = CU->getAddressByteSize();
auto CUDIE = CU->getUnitDIE();
if (!CUDIE)
continue;
if (auto StmtOffset = toSectionOffset(CUDIE.find(DW_AT_stmt_list))) {
DataExtractor lineData(getLineSection().Data, isLittleEndian(),
savedAddressByteSize);
DWARFDebugLine::LineTable LineTable;
uint32_t Offset = *StmtOffset;
LineTable.parse(lineData, &getLineSection().Relocs, &Offset);
LineTable.dump(OS);
}
}
}
if (DumpType == DIDT_All || DumpType == DIDT_CUIndex) {
OS << "\n.debug_cu_index contents:\n";
getCUIndex().dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_TUIndex) {
OS << "\n.debug_tu_index contents:\n";
getTUIndex().dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_LineDwo) {
OS << "\n.debug_line.dwo contents:\n";
unsigned stmtOffset = 0;
DataExtractor lineData(getLineDWOSection().Data, isLittleEndian(),
savedAddressByteSize);
DWARFDebugLine::LineTable LineTable;
while (LineTable.Prologue.parse(lineData, &stmtOffset)) {
LineTable.dump(OS);
LineTable.clear();
}
}
if (DumpType == DIDT_All || DumpType == DIDT_Str) {
OS << "\n.debug_str contents:\n";
DataExtractor strData(getStringSection(), isLittleEndian(), 0);
offset = 0;
uint32_t strOffset = 0;
while (const char *s = strData.getCStr(&offset)) {
OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
strOffset = offset;
}
}
if ((DumpType == DIDT_All || DumpType == DIDT_StrDwo) &&
!getStringDWOSection().empty()) {
OS << "\n.debug_str.dwo contents:\n";
DataExtractor strDWOData(getStringDWOSection(), isLittleEndian(), 0);
offset = 0;
uint32_t strDWOOffset = 0;
while (const char *s = strDWOData.getCStr(&offset)) {
OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
strDWOOffset = offset;
}
}
if (DumpType == DIDT_All || DumpType == DIDT_Ranges) {
OS << "\n.debug_ranges contents:\n";
// In fact, different compile units may have different address byte
// sizes, but for simplicity we just use the address byte size of the last
// compile unit (there is no easy and fast way to associate address range
// list and the compile unit it describes).
DataExtractor rangesData(getRangeSection().Data, isLittleEndian(),
savedAddressByteSize);
offset = 0;
DWARFDebugRangeList rangeList;
while (rangeList.extract(rangesData, &offset, getRangeSection().Relocs))
rangeList.dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Pubnames)
DWARFDebugPubTable(getPubNamesSection(), isLittleEndian(), false)
.dump("debug_pubnames", OS);
if (DumpType == DIDT_All || DumpType == DIDT_Pubtypes)
DWARFDebugPubTable(getPubTypesSection(), isLittleEndian(), false)
.dump("debug_pubtypes", OS);
if (DumpType == DIDT_All || DumpType == DIDT_GnuPubnames)
DWARFDebugPubTable(getGnuPubNamesSection(), isLittleEndian(),
true /* GnuStyle */)
.dump("debug_gnu_pubnames", OS);
if (DumpType == DIDT_All || DumpType == DIDT_GnuPubtypes)
DWARFDebugPubTable(getGnuPubTypesSection(), isLittleEndian(),
true /* GnuStyle */)
.dump("debug_gnu_pubtypes", OS);
if ((DumpType == DIDT_All || DumpType == DIDT_StrOffsetsDwo) &&
!getStringOffsetDWOSection().empty()) {
OS << "\n.debug_str_offsets.dwo contents:\n";
DataExtractor strOffsetExt(getStringOffsetDWOSection(), isLittleEndian(),
0);
offset = 0;
uint64_t size = getStringOffsetDWOSection().size();
while (offset < size) {
OS << format("0x%8.8x: ", offset);
OS << format("%8.8x\n", strOffsetExt.getU32(&offset));
}
}
if ((DumpType == DIDT_All || DumpType == DIDT_GdbIndex) &&
!getGdbIndexSection().empty()) {
OS << "\n.gnu_index contents:\n";
getGdbIndex().dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_AppleNames)
dumpAccelSection(OS, "apple_names", getAppleNamesSection(),
getStringSection(), isLittleEndian());
if (DumpType == DIDT_All || DumpType == DIDT_AppleTypes)
dumpAccelSection(OS, "apple_types", getAppleTypesSection(),
getStringSection(), isLittleEndian());
if (DumpType == DIDT_All || DumpType == DIDT_AppleNamespaces)
dumpAccelSection(OS, "apple_namespaces", getAppleNamespacesSection(),
getStringSection(), isLittleEndian());
if (DumpType == DIDT_All || DumpType == DIDT_AppleObjC)
dumpAccelSection(OS, "apple_objc", getAppleObjCSection(),
getStringSection(), isLittleEndian());
}
DWARFDie DWARFContext::getDIEForOffset(uint32_t Offset) {
parseCompileUnits();
if (auto *CU = CUs.getUnitForOffset(Offset))
return CU->getDIEForOffset(Offset);
return DWARFDie();
}
namespace {
class Verifier {
raw_ostream &OS;
DWARFContext &DCtx;
public:
Verifier(raw_ostream &S, DWARFContext &D) : OS(S), DCtx(D) {}
bool HandleDebugInfo() {
bool Success = true;
// A map that tracks all references (converted absolute references) so we
// can verify each reference points to a valid DIE and not an offset that
// lies between to valid DIEs.
std::map<uint64_t, std::set<uint32_t>> ReferenceToDIEOffsets;
OS << "Verifying .debug_info...\n";
for (const auto &CU : DCtx.compile_units()) {
unsigned NumDies = CU->getNumDIEs();
for (unsigned I = 0; I < NumDies; ++I) {
auto Die = CU->getDIEAtIndex(I);
const auto Tag = Die.getTag();
if (Tag == DW_TAG_null)
continue;
for (auto AttrValue : Die.attributes()) {
const auto Attr = AttrValue.Attr;
const auto Form = AttrValue.Value.getForm();
switch (Attr) {
case DW_AT_ranges:
// Make sure the offset in the DW_AT_ranges attribute is valid.
if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) {
if (*SectionOffset >= DCtx.getRangeSection().Data.size()) {
Success = false;
OS << "error: DW_AT_ranges offset is beyond .debug_ranges "
"bounds:\n";
Die.dump(OS, 0);
OS << "\n";
}
} else {
Success = false;
OS << "error: DIE has invalid DW_AT_ranges encoding:\n";
Die.dump(OS, 0);
OS << "\n";
}
break;
case DW_AT_stmt_list:
// Make sure the offset in the DW_AT_stmt_list attribute is valid.
if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) {
if (*SectionOffset >= DCtx.getLineSection().Data.size()) {
Success = false;
OS << "error: DW_AT_stmt_list offset is beyond .debug_line "
"bounds: "
<< format("0x%08" PRIx32, *SectionOffset) << "\n";
CU->getUnitDIE().dump(OS, 0);
OS << "\n";
}
} else {
Success = false;
OS << "error: DIE has invalid DW_AT_stmt_list encoding:\n";
Die.dump(OS, 0);
OS << "\n";
}
break;
default:
break;
}
switch (Form) {
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata: {
// Verify all CU relative references are valid CU offsets.
Optional<uint64_t> RefVal = AttrValue.Value.getAsReference();
assert(RefVal);
if (RefVal) {
auto DieCU = Die.getDwarfUnit();
auto CUSize = DieCU->getNextUnitOffset() - DieCU->getOffset();
auto CUOffset = AttrValue.Value.getRawUValue();
if (CUOffset >= CUSize) {
Success = false;
OS << "error: " << FormEncodingString(Form) << " CU offset "
<< format("0x%08" PRIx32, CUOffset)
<< " is invalid (must be less than CU size of "
<< format("0x%08" PRIx32, CUSize) << "):\n";
Die.dump(OS, 0);
OS << "\n";
} else {
// Valid reference, but we will verify it points to an actual
// DIE later.
ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset());
}
}
break;
}
case DW_FORM_ref_addr: {
// Verify all absolute DIE references have valid offsets in the
// .debug_info section.
Optional<uint64_t> RefVal = AttrValue.Value.getAsReference();
assert(RefVal);
if (RefVal) {
if(*RefVal >= DCtx.getInfoSection().Data.size()) {
Success = false;
OS << "error: DW_FORM_ref_addr offset beyond .debug_info "
"bounds:\n";
Die.dump(OS, 0);
OS << "\n";
} else {
// Valid reference, but we will verify it points to an actual
// DIE later.
ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset());
}
}
break;
}
case DW_FORM_strp: {
auto SecOffset = AttrValue.Value.getAsSectionOffset();
assert(SecOffset); // DW_FORM_strp is a section offset.
if (SecOffset && *SecOffset >= DCtx.getStringSection().size()) {
Success = false;
OS << "error: DW_FORM_strp offset beyond .debug_str bounds:\n";
Die.dump(OS, 0);
OS << "\n";
}
break;
}
default:
break;
}
}
}
}
// Take all references and make sure they point to an actual DIE by
// getting the DIE by offset and emitting an error
OS << "Verifying .debug_info references...\n";
for (auto Pair: ReferenceToDIEOffsets) {
auto Die = DCtx.getDIEForOffset(Pair.first);
if (Die)
continue;
Success = false;
OS << "error: invalid DIE reference " << format("0x%08" PRIx64, Pair.first)
<< ". Offset is in between DIEs:\n";
for (auto Offset: Pair.second) {
auto ReferencingDie = DCtx.getDIEForOffset(Offset);
ReferencingDie.dump(OS, 0);
OS << "\n";
}
OS << "\n";
}
return Success;
}
};
} // anonymous namespace
bool DWARFContext::verify(raw_ostream &OS, DIDumpType DumpType) {
bool Success = true;
Verifier verifier(OS, *this);
if (DumpType == DIDT_All || DumpType == DIDT_Info) {
if (!verifier.HandleDebugInfo())
Success = false;
}
return Success;
}
const DWARFUnitIndex &DWARFContext::getCUIndex() {
if (CUIndex)
return *CUIndex;
DataExtractor CUIndexData(getCUIndexSection(), isLittleEndian(), 0);
CUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_INFO);
CUIndex->parse(CUIndexData);
return *CUIndex;
}
const DWARFUnitIndex &DWARFContext::getTUIndex() {
if (TUIndex)
return *TUIndex;
DataExtractor TUIndexData(getTUIndexSection(), isLittleEndian(), 0);
TUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_TYPES);
TUIndex->parse(TUIndexData);
return *TUIndex;
}
DWARFGdbIndex &DWARFContext::getGdbIndex() {
if (GdbIndex)
return *GdbIndex;
DataExtractor GdbIndexData(getGdbIndexSection(), true /*LE*/, 0);
GdbIndex = llvm::make_unique<DWARFGdbIndex>();
GdbIndex->parse(GdbIndexData);
return *GdbIndex;
}
const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
if (Abbrev)
return Abbrev.get();
DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
Abbrev.reset(new DWARFDebugAbbrev());
Abbrev->extract(abbrData);
return Abbrev.get();
}
const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
if (AbbrevDWO)
return AbbrevDWO.get();
DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
AbbrevDWO.reset(new DWARFDebugAbbrev());
AbbrevDWO->extract(abbrData);
return AbbrevDWO.get();
}
const DWARFDebugLoc *DWARFContext::getDebugLoc() {
if (Loc)
return Loc.get();
DataExtractor LocData(getLocSection().Data, isLittleEndian(), 0);
Loc.reset(new DWARFDebugLoc(getLocSection().Relocs));
// assume all compile units have the same address byte size
if (getNumCompileUnits())
Loc->parse(LocData, getCompileUnitAtIndex(0)->getAddressByteSize());
return Loc.get();
}
const DWARFDebugLocDWO *DWARFContext::getDebugLocDWO() {
if (LocDWO)
return LocDWO.get();
DataExtractor LocData(getLocDWOSection().Data, isLittleEndian(), 0);
LocDWO.reset(new DWARFDebugLocDWO());
LocDWO->parse(LocData);
return LocDWO.get();
}
const DWARFDebugAranges *DWARFContext::getDebugAranges() {
if (Aranges)
return Aranges.get();
Aranges.reset(new DWARFDebugAranges());
Aranges->generate(this);
return Aranges.get();
}
const DWARFDebugFrame *DWARFContext::getDebugFrame() {
if (DebugFrame)
return DebugFrame.get();
// There's a "bug" in the DWARFv3 standard with respect to the target address
// size within debug frame sections. While DWARF is supposed to be independent
// of its container, FDEs have fields with size being "target address size",
// which isn't specified in DWARF in general. It's only specified for CUs, but
// .eh_frame can appear without a .debug_info section. Follow the example of
// other tools (libdwarf) and extract this from the container (ObjectFile
// provides this information). This problem is fixed in DWARFv4
// See this dwarf-discuss discussion for more details:
// http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
DataExtractor debugFrameData(getDebugFrameSection(), isLittleEndian(),
getAddressSize());
DebugFrame.reset(new DWARFDebugFrame(false /* IsEH */));
DebugFrame->parse(debugFrameData);
return DebugFrame.get();
}
const DWARFDebugFrame *DWARFContext::getEHFrame() {
if (EHFrame)
return EHFrame.get();
DataExtractor debugFrameData(getEHFrameSection(), isLittleEndian(),
getAddressSize());
DebugFrame.reset(new DWARFDebugFrame(true /* IsEH */));
DebugFrame->parse(debugFrameData);
return DebugFrame.get();
}
const DWARFDebugMacro *DWARFContext::getDebugMacro() {
if (Macro)
return Macro.get();
DataExtractor MacinfoData(getMacinfoSection(), isLittleEndian(), 0);
Macro.reset(new DWARFDebugMacro());
Macro->parse(MacinfoData);
return Macro.get();
}
const DWARFLineTable *
DWARFContext::getLineTableForUnit(DWARFUnit *U) {
if (!Line)
Line.reset(new DWARFDebugLine(&getLineSection().Relocs));
auto UnitDIE = U->getUnitDIE();
if (!UnitDIE)
return nullptr;
auto Offset = toSectionOffset(UnitDIE.find(DW_AT_stmt_list));
if (!Offset)
return nullptr; // No line table for this compile unit.
uint32_t stmtOffset = *Offset + U->getLineTableOffset();
// See if the line table is cached.
if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
return lt;
// We have to parse it first.
DataExtractor lineData(U->getLineSection(), isLittleEndian(),
U->getAddressByteSize());
return Line->getOrParseLineTable(lineData, stmtOffset);
}
void DWARFContext::parseCompileUnits() {
CUs.parse(*this, getInfoSection());
}
void DWARFContext::parseTypeUnits() {
if (!TUs.empty())
return;
for (const auto &I : getTypesSections()) {
TUs.emplace_back();
TUs.back().parse(*this, I.second);
}
}
void DWARFContext::parseDWOCompileUnits() {
DWOCUs.parseDWO(*this, getInfoDWOSection());
}
void DWARFContext::parseDWOTypeUnits() {
if (!DWOTUs.empty())
return;
for (const auto &I : getTypesDWOSections()) {
DWOTUs.emplace_back();
DWOTUs.back().parseDWO(*this, I.second);
}
}
DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
parseCompileUnits();
return CUs.getUnitForOffset(Offset);
}
DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
// First, get the offset of the compile unit.
uint32_t CUOffset = getDebugAranges()->findAddress(Address);
// Retrieve the compile unit.
return getCompileUnitForOffset(CUOffset);
}
static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
uint64_t Address,
FunctionNameKind Kind,
std::string &FunctionName,
uint32_t &StartLine) {
// The address may correspond to instruction in some inlined function,
// so we have to build the chain of inlined functions and take the
// name of the topmost function in it.
SmallVector<DWARFDie, 4> InlinedChain;
CU->getInlinedChainForAddress(Address, InlinedChain);
if (InlinedChain.empty())
return false;
const DWARFDie &DIE = InlinedChain[0];
bool FoundResult = false;
const char *Name = nullptr;
if (Kind != FunctionNameKind::None && (Name = DIE.getSubroutineName(Kind))) {
FunctionName = Name;
FoundResult = true;
}
if (auto DeclLineResult = DIE.getDeclLine()) {
StartLine = DeclLineResult;
FoundResult = true;
}
return FoundResult;
}
DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
DILineInfoSpecifier Spec) {
DILineInfo Result;
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return Result;
getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind,
Result.FunctionName,
Result.StartLine);
if (Spec.FLIKind != FileLineInfoKind::None) {
if (const DWARFLineTable *LineTable = getLineTableForUnit(CU))
LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
Spec.FLIKind, Result);
}
return Result;
}
DILineInfoTable
DWARFContext::getLineInfoForAddressRange(uint64_t Address, uint64_t Size,
DILineInfoSpecifier Spec) {
DILineInfoTable Lines;
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return Lines;
std::string FunctionName = "<invalid>";
uint32_t StartLine = 0;
getFunctionNameAndStartLineForAddress(CU, Address, Spec.FNKind, FunctionName,
StartLine);
// If the Specifier says we don't need FileLineInfo, just
// return the top-most function at the starting address.
if (Spec.FLIKind == FileLineInfoKind::None) {
DILineInfo Result;
Result.FunctionName = FunctionName;
Result.StartLine = StartLine;
Lines.push_back(std::make_pair(Address, Result));
return Lines;
}
const DWARFLineTable *LineTable = getLineTableForUnit(CU);
// Get the index of row we're looking for in the line table.
std::vector<uint32_t> RowVector;
if (!LineTable->lookupAddressRange(Address, Size, RowVector))
return Lines;
for (uint32_t RowIndex : RowVector) {
// Take file number and line/column from the row.
const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
DILineInfo Result;
LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
Spec.FLIKind, Result.FileName);
Result.FunctionName = FunctionName;
Result.Line = Row.Line;
Result.Column = Row.Column;
Result.StartLine = StartLine;
Lines.push_back(std::make_pair(Row.Address, Result));
}
return Lines;
}
DIInliningInfo
DWARFContext::getInliningInfoForAddress(uint64_t Address,
DILineInfoSpecifier Spec) {
DIInliningInfo InliningInfo;
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return InliningInfo;
const DWARFLineTable *LineTable = nullptr;
SmallVector<DWARFDie, 4> InlinedChain;
CU->getInlinedChainForAddress(Address, InlinedChain);
if (InlinedChain.size() == 0) {
// If there is no DIE for address (e.g. it is in unavailable .dwo file),
// try to at least get file/line info from symbol table.
if (Spec.FLIKind != FileLineInfoKind::None) {
DILineInfo Frame;
LineTable = getLineTableForUnit(CU);
if (LineTable &&
LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
Spec.FLIKind, Frame))
InliningInfo.addFrame(Frame);
}
return InliningInfo;
}
uint32_t CallFile = 0, CallLine = 0, CallColumn = 0, CallDiscriminator = 0;
for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) {
DWARFDie &FunctionDIE = InlinedChain[i];
DILineInfo Frame;
// Get function name if necessary.
if (const char *Name = FunctionDIE.getSubroutineName(Spec.FNKind))
Frame.FunctionName = Name;
if (auto DeclLineResult = FunctionDIE.getDeclLine())
Frame.StartLine = DeclLineResult;
if (Spec.FLIKind != FileLineInfoKind::None) {
if (i == 0) {
// For the topmost frame, initialize the line table of this
// compile unit and fetch file/line info from it.
LineTable = getLineTableForUnit(CU);
// For the topmost routine, get file/line info from line table.
if (LineTable)
LineTable->getFileLineInfoForAddress(Address, CU->getCompilationDir(),
Spec.FLIKind, Frame);
} else {
// Otherwise, use call file, call line and call column from
// previous DIE in inlined chain.
if (LineTable)
LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
Spec.FLIKind, Frame.FileName);
Frame.Line = CallLine;
Frame.Column = CallColumn;
Frame.Discriminator = CallDiscriminator;
}
// Get call file/line/column of a current DIE.
if (i + 1 < n) {
FunctionDIE.getCallerFrame(CallFile, CallLine, CallColumn,
CallDiscriminator);
}
}
InliningInfo.addFrame(Frame);
}
return InliningInfo;
}
static Error createError(const Twine &Reason, llvm::Error E) {
return make_error<StringError>(Reason + toString(std::move(E)),
inconvertibleErrorCode());
}
/// Returns the address of symbol relocation used against. Used for futher
/// relocations computation. Symbol's section load address is taken in account if
/// LoadedObjectInfo interface is provided.
static Expected<uint64_t> getSymbolAddress(const object::ObjectFile &Obj,
const RelocationRef &Reloc,
const LoadedObjectInfo *L) {
uint64_t Ret = 0;
object::section_iterator RSec = Obj.section_end();
object::symbol_iterator Sym = Reloc.getSymbol();
// First calculate the address of the symbol or section as it appears
// in the object file
if (Sym != Obj.symbol_end()) {
Expected<uint64_t> SymAddrOrErr = Sym->getAddress();
if (!SymAddrOrErr)
return createError("error: failed to compute symbol address: ",
SymAddrOrErr.takeError());
// Also remember what section this symbol is in for later
auto SectOrErr = Sym->getSection();
if (!SectOrErr)
return createError("error: failed to get symbol section: ",
SectOrErr.takeError());
RSec = *SectOrErr;
Ret = *SymAddrOrErr;
} else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
Ret = RSec->getAddress();
}
// If we are given load addresses for the sections, we need to adjust:
// SymAddr = (Address of Symbol Or Section in File) -
// (Address of Section in File) +
// (Load Address of Section)
// RSec is now either the section being targeted or the section
// containing the symbol being targeted. In either case,
// we need to perform the same computation.
if (L && RSec != Obj.section_end())
if (uint64_t SectionLoadAddress = L->getSectionLoadAddress(*RSec))
Ret += SectionLoadAddress - RSec->getAddress();
return Ret;
}
static bool isRelocScattered(const object::ObjectFile &Obj,
const RelocationRef &Reloc) {
const MachOObjectFile *MachObj = dyn_cast<MachOObjectFile>(&Obj);
if (!MachObj)
return false;
// MachO also has relocations that point to sections and
// scattered relocations.
auto RelocInfo = MachObj->getRelocation(Reloc.getRawDataRefImpl());
return MachObj->isRelocationScattered(RelocInfo);
}
DWARFContextInMemory::DWARFContextInMemory(const object::ObjectFile &Obj,
const LoadedObjectInfo *L)
: IsLittleEndian(Obj.isLittleEndian()),
AddressSize(Obj.getBytesInAddress()) {
for (const SectionRef &Section : Obj.sections()) {
StringRef name;
Section.getName(name);
// Skip BSS and Virtual sections, they aren't interesting.
bool IsBSS = Section.isBSS();
if (IsBSS)
continue;
bool IsVirtual = Section.isVirtual();
if (IsVirtual)
continue;
StringRef data;
section_iterator RelocatedSection = Section.getRelocatedSection();
// Try to obtain an already relocated version of this section.
// Else use the unrelocated section from the object file. We'll have to
// apply relocations ourselves later.
if (!L || !L->getLoadedSectionContents(*RelocatedSection,data))
Section.getContents(data);
if (Decompressor::isCompressed(Section)) {
Expected<Decompressor> Decompressor =
Decompressor::create(name, data, IsLittleEndian, AddressSize == 8);
if (!Decompressor)
continue;
SmallString<32> Out;
if (auto Err = Decompressor->decompress(Out))
continue;
UncompressedSections.emplace_back(std::move(Out));
data = UncompressedSections.back();
}
// Compressed sections names in GNU style starts from ".z",
// at this point section is decompressed and we drop compression prefix.
name = name.substr(
name.find_first_not_of("._z")); // Skip ".", "z" and "_" prefixes.
if (StringRef *SectionData = MapSectionToMember(name)) {
*SectionData = data;
if (name == "debug_ranges") {
// FIXME: Use the other dwo range section when we emit it.
RangeDWOSection.Data = data;
}
} else if (name == "debug_types") {
// Find debug_types data by section rather than name as there are
// multiple, comdat grouped, debug_types sections.
TypesSections[Section].Data = data;
} else if (name == "debug_types.dwo") {
TypesDWOSections[Section].Data = data;
}
if (RelocatedSection == Obj.section_end())
continue;
StringRef RelSecName;
StringRef RelSecData;
RelocatedSection->getName(RelSecName);
// If the section we're relocating was relocated already by the JIT,
// then we used the relocated version above, so we do not need to process
// relocations for it now.
if (L && L->getLoadedSectionContents(*RelocatedSection,RelSecData))
continue;
// In Mach-o files, the relocations do not need to be applied if
// there is no load offset to apply. The value read at the
// relocation point already factors in the section address
// (actually applying the relocations will produce wrong results
// as the section address will be added twice).
if (!L && isa<MachOObjectFile>(&Obj))
continue;
RelSecName = RelSecName.substr(
RelSecName.find_first_not_of("._")); // Skip . and _ prefixes.
// TODO: Add support for relocations in other sections as needed.
// Record relocations for the debug_info and debug_line sections.
RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(RelSecName)
.Case("debug_info", &InfoSection.Relocs)
.Case("debug_loc", &LocSection.Relocs)
.Case("debug_info.dwo", &InfoDWOSection.Relocs)
.Case("debug_line", &LineSection.Relocs)
.Case("debug_ranges", &RangeSection.Relocs)
.Case("apple_names", &AppleNamesSection.Relocs)
.Case("apple_types", &AppleTypesSection.Relocs)
.Case("apple_namespaces", &AppleNamespacesSection.Relocs)
.Case("apple_namespac", &AppleNamespacesSection.Relocs)
.Case("apple_objc", &AppleObjCSection.Relocs)
.Default(nullptr);
if (!Map) {
// Find debug_types relocs by section rather than name as there are
// multiple, comdat grouped, debug_types sections.
if (RelSecName == "debug_types")
Map = &TypesSections[*RelocatedSection].Relocs;
else if (RelSecName == "debug_types.dwo")
Map = &TypesDWOSections[*RelocatedSection].Relocs;
else
continue;
}
if (Section.relocation_begin() != Section.relocation_end()) {
uint64_t SectionSize = RelocatedSection->getSize();
for (const RelocationRef &Reloc : Section.relocations()) {
// FIXME: it's not clear how to correctly handle scattered
// relocations.
if (isRelocScattered(Obj, Reloc))
continue;
Expected<uint64_t> SymAddrOrErr = getSymbolAddress(Obj, Reloc, L);
if (!SymAddrOrErr) {
errs() << toString(SymAddrOrErr.takeError()) << '\n';
continue;
}
object::RelocVisitor V(Obj);
object::RelocToApply R(V.visit(Reloc.getType(), Reloc, *SymAddrOrErr));
if (V.error()) {
SmallString<32> Name;
Reloc.getTypeName(Name);
errs() << "error: failed to compute relocation: "
<< Name << "\n";
continue;
}
uint64_t Address = Reloc.getOffset();
if (Address + R.Width > SectionSize) {
errs() << "error: " << R.Width << "-byte relocation starting "
<< Address << " bytes into section " << name << " which is "
<< SectionSize << " bytes long.\n";
continue;
}
if (R.Width > 8) {
errs() << "error: can't handle a relocation of more than 8 bytes at "
"a time.\n";
continue;
}
DEBUG(dbgs() << "Writing " << format("%p", R.Value)
<< " at " << format("%p", Address)
<< " with width " << format("%d", R.Width)
<< "\n");
Map->insert(std::make_pair(Address, std::make_pair(R.Width, R.Value)));
}
}
}
}
DWARFContextInMemory::DWARFContextInMemory(
const StringMap<std::unique_ptr<MemoryBuffer>> &Sections, uint8_t AddrSize,
bool isLittleEndian)
: IsLittleEndian(isLittleEndian), AddressSize(AddrSize) {
for (const auto &SecIt : Sections) {
if (StringRef *SectionData = MapSectionToMember(SecIt.first()))
*SectionData = SecIt.second->getBuffer();
}
}
StringRef *DWARFContextInMemory::MapSectionToMember(StringRef Name) {
return StringSwitch<StringRef *>(Name)
.Case("debug_info", &InfoSection.Data)
.Case("debug_abbrev", &AbbrevSection)
.Case("debug_loc", &LocSection.Data)
.Case("debug_line", &LineSection.Data)
.Case("debug_aranges", &ARangeSection)
.Case("debug_frame", &DebugFrameSection)
.Case("eh_frame", &EHFrameSection)
.Case("debug_str", &StringSection)
.Case("debug_ranges", &RangeSection.Data)
.Case("debug_macinfo", &MacinfoSection)
.Case("debug_pubnames", &PubNamesSection)
.Case("debug_pubtypes", &PubTypesSection)
.Case("debug_gnu_pubnames", &GnuPubNamesSection)
.Case("debug_gnu_pubtypes", &GnuPubTypesSection)
.Case("debug_info.dwo", &InfoDWOSection.Data)
.Case("debug_abbrev.dwo", &AbbrevDWOSection)
.Case("debug_loc.dwo", &LocDWOSection.Data)
.Case("debug_line.dwo", &LineDWOSection.Data)
.Case("debug_str.dwo", &StringDWOSection)
.Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
.Case("debug_addr", &AddrSection)
.Case("apple_names", &AppleNamesSection.Data)
.Case("apple_types", &AppleTypesSection.Data)
.Case("apple_namespaces", &AppleNamespacesSection.Data)
.Case("apple_namespac", &AppleNamespacesSection.Data)
.Case("apple_objc", &AppleObjCSection.Data)
.Case("debug_cu_index", &CUIndexSection)
.Case("debug_tu_index", &TUIndexSection)
.Case("gdb_index", &GdbIndexSection)
// Any more debug info sections go here.
.Default(nullptr);
}
void DWARFContextInMemory::anchor() {}
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