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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 "DWARFContext.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Compression.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
using namespace dwarf;
typedef DWARFDebugLine::LineTable DWARFLineTable;
void DWARFContext::dump(raw_ostream &OS, DIDumpType DumpType) {
if (DumpType == DIDT_All || DumpType == DIDT_Abbrev) {
OS << ".debug_abbrev contents:\n";
getDebugAbbrev()->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Info) {
OS << "\n.debug_info contents:\n";
for (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i)
getCompileUnitAtIndex(i)->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
OS << "\n.debug_frame contents:\n";
getDebugFrame()->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 (unsigned i = 0, e = getNumCompileUnits(); i != e; ++i) {
DWARFCompileUnit *cu = getCompileUnitAtIndex(i);
savedAddressByteSize = cu->getAddressByteSize();
unsigned stmtOffset =
cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
-1U);
if (stmtOffset != -1U) {
DataExtractor lineData(getLineSection(), isLittleEndian(),
savedAddressByteSize);
DWARFDebugLine::DumpingState state(OS);
DWARFDebugLine::parseStatementTable(lineData, &lineRelocMap(), &stmtOffset, state);
}
}
}
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_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(), isLittleEndian(),
savedAddressByteSize);
offset = 0;
DWARFDebugRangeList rangeList;
while (rangeList.extract(rangesData, &offset))
rangeList.dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_Pubnames) {
OS << "\n.debug_pubnames contents:\n";
DataExtractor pubNames(getPubNamesSection(), isLittleEndian(), 0);
offset = 0;
OS << "Length: " << pubNames.getU32(&offset) << "\n";
OS << "Version: " << pubNames.getU16(&offset) << "\n";
OS << "Offset in .debug_info: " << pubNames.getU32(&offset) << "\n";
OS << "Size: " << pubNames.getU32(&offset) << "\n";
OS << "\n Offset Name\n";
while (offset < getPubNamesSection().size()) {
uint32_t n = pubNames.getU32(&offset);
if (n == 0)
break;
OS << format("%8x ", n);
OS << pubNames.getCStr(&offset) << "\n";
}
}
if (DumpType == DIDT_All || DumpType == DIDT_AbbrevDwo) {
const DWARFDebugAbbrev *D = getDebugAbbrevDWO();
if (D) {
OS << "\n.debug_abbrev.dwo contents:\n";
getDebugAbbrevDWO()->dump(OS);
}
}
if (DumpType == DIDT_All || DumpType == DIDT_InfoDwo)
if (getNumDWOCompileUnits()) {
OS << "\n.debug_info.dwo contents:\n";
for (unsigned i = 0, e = getNumDWOCompileUnits(); i != e; ++i)
getDWOCompileUnitAtIndex(i)->dump(OS);
}
if (DumpType == DIDT_All || DumpType == DIDT_StrDwo)
if (!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_StrOffsetsDwo)
if (!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));
}
}
}
const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
if (Abbrev)
return Abbrev.get();
DataExtractor abbrData(getAbbrevSection(), isLittleEndian(), 0);
Abbrev.reset(new DWARFDebugAbbrev());
Abbrev->parse(abbrData);
return Abbrev.get();
}
const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
if (AbbrevDWO)
return AbbrevDWO.get();
DataExtractor abbrData(getAbbrevDWOSection(), isLittleEndian(), 0);
AbbrevDWO.reset(new DWARFDebugAbbrev());
AbbrevDWO->parse(abbrData);
return AbbrevDWO.get();
}
const DWARFDebugAranges *DWARFContext::getDebugAranges() {
if (Aranges)
return Aranges.get();
DataExtractor arangesData(getARangeSection(), isLittleEndian(), 0);
Aranges.reset(new DWARFDebugAranges());
Aranges->extract(arangesData);
// Generate aranges from DIEs: even if .debug_aranges section is present,
// it may describe only a small subset of compilation units, so we need to
// manually build aranges for the rest of them.
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());
DebugFrame->parse(debugFrameData);
return DebugFrame.get();
}
const DWARFLineTable *
DWARFContext::getLineTableForCompileUnit(DWARFCompileUnit *cu) {
if (!Line)
Line.reset(new DWARFDebugLine(&lineRelocMap()));
unsigned stmtOffset =
cu->getCompileUnitDIE()->getAttributeValueAsUnsigned(cu, DW_AT_stmt_list,
-1U);
if (stmtOffset == -1U)
return 0; // No line table for this compile unit.
// See if the line table is cached.
if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
return lt;
// We have to parse it first.
DataExtractor lineData(getLineSection(), isLittleEndian(),
cu->getAddressByteSize());
return Line->getOrParseLineTable(lineData, stmtOffset);
}
void DWARFContext::parseCompileUnits() {
uint32_t offset = 0;
const DataExtractor &DIData = DataExtractor(getInfoSection(),
isLittleEndian(), 0);
while (DIData.isValidOffset(offset)) {
CUs.push_back(DWARFCompileUnit(getDebugAbbrev(), getInfoSection(),
getAbbrevSection(), getRangeSection(),
getStringSection(), StringRef(),
getAddrSection(),
&infoRelocMap(),
isLittleEndian()));
if (!CUs.back().extract(DIData, &offset)) {
CUs.pop_back();
break;
}
offset = CUs.back().getNextCompileUnitOffset();
}
}
void DWARFContext::parseDWOCompileUnits() {
uint32_t offset = 0;
const DataExtractor &DIData = DataExtractor(getInfoDWOSection(),
isLittleEndian(), 0);
while (DIData.isValidOffset(offset)) {
DWOCUs.push_back(DWARFCompileUnit(getDebugAbbrevDWO(), getInfoDWOSection(),
getAbbrevDWOSection(),
getRangeDWOSection(),
getStringDWOSection(),
getStringOffsetDWOSection(),
getAddrSection(),
&infoDWORelocMap(),
isLittleEndian()));
if (!DWOCUs.back().extract(DIData, &offset)) {
DWOCUs.pop_back();
break;
}
offset = DWOCUs.back().getNextCompileUnitOffset();
}
}
namespace {
struct OffsetComparator {
bool operator()(const DWARFCompileUnit &LHS,
const DWARFCompileUnit &RHS) const {
return LHS.getOffset() < RHS.getOffset();
}
bool operator()(const DWARFCompileUnit &LHS, uint32_t RHS) const {
return LHS.getOffset() < RHS;
}
bool operator()(uint32_t LHS, const DWARFCompileUnit &RHS) const {
return LHS < RHS.getOffset();
}
};
}
DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
if (CUs.empty())
parseCompileUnits();
DWARFCompileUnit *CU = std::lower_bound(CUs.begin(), CUs.end(), Offset,
OffsetComparator());
if (CU != CUs.end())
return &*CU;
return 0;
}
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 getFileNameForCompileUnit(DWARFCompileUnit *CU,
const DWARFLineTable *LineTable,
uint64_t FileIndex,
bool NeedsAbsoluteFilePath,
std::string &FileName) {
if (CU == 0 ||
LineTable == 0 ||
!LineTable->getFileNameByIndex(FileIndex, NeedsAbsoluteFilePath,
FileName))
return false;
if (NeedsAbsoluteFilePath && sys::path::is_relative(FileName)) {
// We may still need to append compilation directory of compile unit.
SmallString<16> AbsolutePath;
if (const char *CompilationDir = CU->getCompilationDir()) {
sys::path::append(AbsolutePath, CompilationDir);
}
sys::path::append(AbsolutePath, FileName);
FileName = AbsolutePath.str();
}
return true;
}
static bool getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
const DWARFLineTable *LineTable,
uint64_t Address,
bool NeedsAbsoluteFilePath,
std::string &FileName,
uint32_t &Line, uint32_t &Column) {
if (CU == 0 || LineTable == 0)
return false;
// Get the index of row we're looking for in the line table.
uint32_t RowIndex = LineTable->lookupAddress(Address);
if (RowIndex == -1U)
return false;
// Take file number and line/column from the row.
const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
if (!getFileNameForCompileUnit(CU, LineTable, Row.File,
NeedsAbsoluteFilePath, FileName))
return false;
Line = Row.Line;
Column = Row.Column;
return true;
}
DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
DILineInfoSpecifier Specifier) {
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return DILineInfo();
std::string FileName = "<invalid>";
std::string FunctionName = "<invalid>";
uint32_t Line = 0;
uint32_t Column = 0;
if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
// 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.
const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
CU->getInlinedChainForAddress(Address);
if (InlinedChain.size() > 0) {
const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0];
if (const char *Name = TopFunctionDIE.getSubroutineName(CU))
FunctionName = Name;
}
}
if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
const bool NeedsAbsoluteFilePath =
Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
getFileLineInfoForCompileUnit(CU, LineTable, Address,
NeedsAbsoluteFilePath,
FileName, Line, Column);
}
return DILineInfo(StringRef(FileName), StringRef(FunctionName),
Line, Column);
}
DILineInfoTable DWARFContext::getLineInfoForAddressRange(uint64_t Address,
uint64_t Size,
DILineInfoSpecifier Specifier) {
DILineInfoTable Lines;
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return Lines;
std::string FunctionName = "<invalid>";
if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
// 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.
const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
CU->getInlinedChainForAddress(Address);
if (InlinedChain.size() > 0) {
const DWARFDebugInfoEntryMinimal &TopFunctionDIE = InlinedChain[0];
if (const char *Name = TopFunctionDIE.getSubroutineName(CU))
FunctionName = Name;
}
}
StringRef FuncNameRef = StringRef(FunctionName);
// If the Specifier says we don't need FileLineInfo, just
// return the top-most function at the starting address.
if (!Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
Lines.push_back(std::make_pair(Address,
DILineInfo(StringRef("<invalid>"),
FuncNameRef, 0, 0)));
return Lines;
}
const DWARFLineTable *LineTable = getLineTableForCompileUnit(CU);
const bool NeedsAbsoluteFilePath =
Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
// 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;
uint32_t NumRows = RowVector.size();
for (uint32_t i = 0; i < NumRows; ++i) {
uint32_t RowIndex = RowVector[i];
// Take file number and line/column from the row.
const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
std::string FileName = "<invalid>";
getFileNameForCompileUnit(CU, LineTable, Row.File,
NeedsAbsoluteFilePath, FileName);
Lines.push_back(std::make_pair(Row.Address,
DILineInfo(StringRef(FileName),
FuncNameRef, Row.Line, Row.Column)));
}
return Lines;
}
DIInliningInfo DWARFContext::getInliningInfoForAddress(uint64_t Address,
DILineInfoSpecifier Specifier) {
DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
if (!CU)
return DIInliningInfo();
const DWARFDebugInfoEntryMinimal::InlinedChain &InlinedChain =
CU->getInlinedChainForAddress(Address);
if (InlinedChain.size() == 0)
return DIInliningInfo();
DIInliningInfo InliningInfo;
uint32_t CallFile = 0, CallLine = 0, CallColumn = 0;
const DWARFLineTable *LineTable = 0;
for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) {
const DWARFDebugInfoEntryMinimal &FunctionDIE = InlinedChain[i];
std::string FileName = "<invalid>";
std::string FunctionName = "<invalid>";
uint32_t Line = 0;
uint32_t Column = 0;
// Get function name if necessary.
if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
if (const char *Name = FunctionDIE.getSubroutineName(CU))
FunctionName = Name;
}
if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
const bool NeedsAbsoluteFilePath =
Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
if (i == 0) {
// For the topmost frame, initialize the line table of this
// compile unit and fetch file/line info from it.
LineTable = getLineTableForCompileUnit(CU);
// For the topmost routine, get file/line info from line table.
getFileLineInfoForCompileUnit(CU, LineTable, Address,
NeedsAbsoluteFilePath,
FileName, Line, Column);
} else {
// Otherwise, use call file, call line and call column from
// previous DIE in inlined chain.
getFileNameForCompileUnit(CU, LineTable, CallFile,
NeedsAbsoluteFilePath, FileName);
Line = CallLine;
Column = CallColumn;
}
// Get call file/line/column of a current DIE.
if (i + 1 < n) {
FunctionDIE.getCallerFrame(CU, CallFile, CallLine, CallColumn);
}
}
DILineInfo Frame(StringRef(FileName), StringRef(FunctionName),
Line, Column);
InliningInfo.addFrame(Frame);
}
return InliningInfo;
}
static bool consumeCompressedDebugSectionHeader(StringRef &data,
uint64_t &OriginalSize) {
// Consume "ZLIB" prefix.
if (!data.startswith("ZLIB"))
return false;
data = data.substr(4);
// Consume uncompressed section size (big-endian 8 bytes).
DataExtractor extractor(data, false, 8);
uint32_t Offset = 0;
OriginalSize = extractor.getU64(&Offset);
if (Offset == 0)
return false;
data = data.substr(Offset);
return true;
}
DWARFContextInMemory::DWARFContextInMemory(object::ObjectFile *Obj) :
IsLittleEndian(Obj->isLittleEndian()),
AddressSize(Obj->getBytesInAddress()) {
error_code ec;
for (object::section_iterator i = Obj->begin_sections(),
e = Obj->end_sections();
i != e; i.increment(ec)) {
StringRef name;
i->getName(name);
StringRef data;
i->getContents(data);
name = name.substr(name.find_first_not_of("._")); // Skip . and _ prefixes.
// Check if debug info section is compressed with zlib.
if (name.startswith("zdebug_")) {
uint64_t OriginalSize;
if (!zlib::isAvailable() ||
!consumeCompressedDebugSectionHeader(data, OriginalSize))
continue;
OwningPtr<MemoryBuffer> UncompressedSection;
if (zlib::uncompress(data, UncompressedSection, OriginalSize) !=
zlib::StatusOK)
continue;
// Make data point to uncompressed section contents and save its contents.
name = name.substr(1);
data = UncompressedSection->getBuffer();
UncompressedSections.push_back(UncompressedSection.take());
}
StringRef *Section = StringSwitch<StringRef*>(name)
.Case("debug_info", &InfoSection)
.Case("debug_abbrev", &AbbrevSection)
.Case("debug_line", &LineSection)
.Case("debug_aranges", &ARangeSection)
.Case("debug_frame", &DebugFrameSection)
.Case("debug_str", &StringSection)
.Case("debug_ranges", &RangeSection)
.Case("debug_pubnames", &PubNamesSection)
.Case("debug_info.dwo", &InfoDWOSection)
.Case("debug_abbrev.dwo", &AbbrevDWOSection)
.Case("debug_str.dwo", &StringDWOSection)
.Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
.Case("debug_addr", &AddrSection)
// Any more debug info sections go here.
.Default(0);
if (!Section)
continue;
*Section = data;
if (name == "debug_ranges") {
// FIXME: Use the other dwo range section when we emit it.
RangeDWOSection = data;
}
// TODO: Add support for relocations in other sections as needed.
// Record relocations for the debug_info and debug_line sections.
RelocAddrMap *Map = StringSwitch<RelocAddrMap*>(name)
.Case("debug_info", &InfoRelocMap)
.Case("debug_info.dwo", &InfoDWORelocMap)
.Case("debug_line", &LineRelocMap)
.Default(0);
if (!Map)
continue;
if (i->begin_relocations() != i->end_relocations()) {
uint64_t SectionSize;
i->getSize(SectionSize);
for (object::relocation_iterator reloc_i = i->begin_relocations(),
reloc_e = i->end_relocations();
reloc_i != reloc_e; reloc_i.increment(ec)) {
uint64_t Address;
reloc_i->getOffset(Address);
uint64_t Type;
reloc_i->getType(Type);
uint64_t SymAddr = 0;
// ELF relocations may need the symbol address
if (Obj->isELF()) {
object::SymbolRef Sym;
reloc_i->getSymbol(Sym);
Sym.getAddress(SymAddr);
}
object::RelocVisitor V(Obj->getFileFormatName());
// The section address is always 0 for debug sections.
object::RelocToApply R(V.visit(Type, *reloc_i, 0, SymAddr));
if (V.error()) {
SmallString<32> Name;
error_code ec(reloc_i->getTypeName(Name));
if (ec) {
errs() << "Aaaaaa! Nameless relocation! Aaaaaa!\n";
}
errs() << "error: failed to compute relocation: "
<< Name << "\n";
continue;
}
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() {
DeleteContainerPointers(UncompressedSections);
}
void DWARFContextInMemory::anchor() { }