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| //===- DWARFDebugAranges.cpp ----------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/WithColor.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <set>
#include <vector>
using namespace llvm;
void DWARFDebugAranges::extract(DataExtractor DebugArangesData) {
if (!DebugArangesData.isValidOffset(0))
return;
uint64_t Offset = 0;
DWARFDebugArangeSet Set;
while (Set.extract(DebugArangesData, &Offset)) {
uint64_t CUOffset = Set.getCompileUnitDIEOffset();
for (const auto &Desc : Set.descriptors()) {
uint64_t LowPC = Desc.Address;
uint64_t HighPC = Desc.getEndAddress();
appendRange(CUOffset, LowPC, HighPC);
}
ParsedCUOffsets.insert(CUOffset);
}
}
void DWARFDebugAranges::generate(DWARFContext *CTX) {
clear();
if (!CTX)
return;
// Extract aranges from .debug_aranges section.
DataExtractor ArangesData(CTX->getDWARFObj().getArangesSection(),
CTX->isLittleEndian(), 0);
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.
for (const auto &CU : CTX->compile_units()) {
uint64_t CUOffset = CU->getOffset();
if (ParsedCUOffsets.insert(CUOffset).second) {
Expected<DWARFAddressRangesVector> CURanges = CU->collectAddressRanges();
if (!CURanges)
WithColor::error() << toString(CURanges.takeError()) << '\n';
else
for (const auto &R : *CURanges)
appendRange(CUOffset, R.LowPC, R.HighPC);
}
}
construct();
}
void DWARFDebugAranges::clear() {
Endpoints.clear();
Aranges.clear();
ParsedCUOffsets.clear();
}
void DWARFDebugAranges::appendRange(uint64_t CUOffset, uint64_t LowPC,
uint64_t HighPC) {
if (LowPC >= HighPC)
return;
Endpoints.emplace_back(LowPC, CUOffset, true);
Endpoints.emplace_back(HighPC, CUOffset, false);
}
void DWARFDebugAranges::construct() {
std::multiset<uint64_t> ValidCUs; // Maintain the set of CUs describing
// a current address range.
llvm::sort(Endpoints);
uint64_t PrevAddress = -1ULL;
for (const auto &E : Endpoints) {
if (PrevAddress < E.Address && !ValidCUs.empty()) {
// If the address range between two endpoints is described by some
// CU, first try to extend the last range in Aranges. If we can't
// do it, start a new range.
if (!Aranges.empty() && Aranges.back().HighPC() == PrevAddress &&
ValidCUs.find(Aranges.back().CUOffset) != ValidCUs.end()) {
Aranges.back().setHighPC(E.Address);
} else {
Aranges.emplace_back(PrevAddress, E.Address, *ValidCUs.begin());
}
}
// Update the set of valid CUs.
if (E.IsRangeStart) {
ValidCUs.insert(E.CUOffset);
} else {
auto CUPos = ValidCUs.find(E.CUOffset);
assert(CUPos != ValidCUs.end());
ValidCUs.erase(CUPos);
}
PrevAddress = E.Address;
}
assert(ValidCUs.empty());
// Endpoints are not needed now.
Endpoints.clear();
Endpoints.shrink_to_fit();
}
uint32_t DWARFDebugAranges::findAddress(uint64_t Address) const {
RangeCollIterator It =
partition_point(Aranges, [=](Range R) { return R.HighPC() <= Address; });
if (It != Aranges.end() && It->LowPC <= Address)
return It->CUOffset;
return -1U;
}
|