llvm/lib/DebugInfo/DWARFDebugLoc.cpp
David Blaikie b13d54f588 DebugInfo: Support debug_loc under fission
Implement debug_loc.dwo, as well as llvm-dwarfdump support for dumping
this section.

Outlined in the DWARF5 spec and http://gcc.gnu.org/wiki/DebugFission the
debug_loc.dwo section has more variation than the standard debug_loc,
allowing 3 different forms of entry (plus the end of list entry). GCC
seems to, and Clang certainly, only use one form, so I've just
implemented dumping support for that for now.

It wasn't immediately obvious that there was a good refactoring to share
the implementation of dumping support between debug_loc and
debug_loc.dwo, so they're separate for now - ideas welcome or I may come
back to it at some point.

As per a comment in the code, we could choose different forms that may
reduce the number of debug_addr entries we emit, but that will require
further study.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204697 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-25 01:44:02 +00:00

129 lines
4.2 KiB
C++

//===-- DWARFDebugLoc.cpp -------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "DWARFDebugLoc.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Dwarf.h"
using namespace llvm;
void DWARFDebugLoc::dump(raw_ostream &OS) const {
for (const LocationList &L : Locations) {
OS << format("0x%8.8x: ", L.Offset);
const unsigned Indent = 12;
for (const Entry &E : L.Entries) {
if (&E != L.Entries.begin())
OS.indent(Indent);
OS << "Beginning address offset: " << format("0x%016" PRIx64, E.Begin)
<< '\n';
OS.indent(Indent) << " Ending address offset: "
<< format("0x%016" PRIx64, E.End) << '\n';
OS.indent(Indent) << " Location description: ";
for (unsigned char Loc : E.Loc) {
OS << format("%2.2x ", Loc);
}
OS << "\n\n";
}
}
}
void DWARFDebugLoc::parse(DataExtractor data, unsigned AddressSize) {
uint32_t Offset = 0;
while (data.isValidOffset(Offset+AddressSize-1)) {
Locations.resize(Locations.size() + 1);
LocationList &Loc = Locations.back();
Loc.Offset = Offset;
// 2.6.2 Location Lists
// A location list entry consists of:
while (true) {
Entry E;
RelocAddrMap::const_iterator AI = RelocMap.find(Offset);
// 1. A beginning address offset. ...
E.Begin = data.getUnsigned(&Offset, AddressSize);
if (AI != RelocMap.end())
E.Begin += AI->second.second;
AI = RelocMap.find(Offset);
// 2. An ending address offset. ...
E.End = data.getUnsigned(&Offset, AddressSize);
if (AI != RelocMap.end())
E.End += AI->second.second;
// 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)
break;
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.reserve(str.size());
std::copy(str.begin(), str.end(), std::back_inserter(E.Loc));
Loc.Entries.push_back(std::move(E));
}
}
if (data.isValidOffset(Offset))
llvm::errs() << "error: failed to consume entire .debug_loc section\n";
}
void DWARFDebugLocDWO::parse(DataExtractor data) {
uint32_t Offset = 0;
while (data.isValidOffset(Offset)) {
Locations.resize(Locations.size() + 1);
LocationList &Loc = Locations.back();
Loc.Offset = Offset;
dwarf::LocationListEntry Kind;
while ((Kind = static_cast<dwarf::LocationListEntry>(
data.getU8(&Offset))) != dwarf::DW_LLE_end_of_list_entry) {
if (Kind != dwarf::DW_LLE_start_length_entry) {
llvm::errs() << "error: dumping support for LLE of kind " << (int)Kind
<< " not implemented\n";
return;
}
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());
Loc.Entries.push_back(std::move(E));
}
}
}
void DWARFDebugLocDWO::dump(raw_ostream &OS) const {
for (const LocationList &L : Locations) {
OS << format("0x%8.8x: ", L.Offset);
const unsigned Indent = 12;
for (const Entry &E : L.Entries) {
if (&E != L.Entries.begin())
OS.indent(Indent);
OS << "Beginning address index: " << E.Start << '\n';
OS.indent(Indent) << " Length: " << E.Length << '\n';
OS.indent(Indent) << " Location description: ";
for (unsigned char Loc : E.Loc)
OS << format("%2.2x ", Loc);
OS << "\n\n";
}
}
}