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//===------- EHFrameSupportImpl.h - JITLink eh-frame utils ------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// EHFrame registration support for JITLink.
#include "llvm/ExecutionEngine/JITLink/EHFrameSupport.h"
#include "llvm/ExecutionEngine/JITLink/JITLink.h"
#include "llvm/Support/BinaryStreamReader.h"
namespace llvm {
namespace jitlink {
/// A LinkGraph pass that splits blocks in an eh-frame section into sub-blocks
/// representing individual eh-frames.
/// EHFrameSplitter should not be run without EHFrameEdgeFixer, which is
/// responsible for adding FDE-to-CIE edges.
class EHFrameSplitter {
EHFrameSplitter(StringRef EHFrameSectionName);
Error operator()(LinkGraph &G);
Error processBlock(LinkGraph &G, Block &B, LinkGraph::SplitBlockCache &Cache);
StringRef EHFrameSectionName;
/// A LinkGraph pass that adds missing FDE-to-CIE, FDE-to-PC and FDE-to-LSDA
/// edges.
class EHFrameEdgeFixer {
EHFrameEdgeFixer(StringRef EHFrameSectionName, unsigned PointerSize,
Edge::Kind Delta64, Edge::Kind Delta32,
Edge::Kind NegDelta32);
Error operator()(LinkGraph &G);
struct AugmentationInfo {
bool AugmentationDataPresent = false;
bool EHDataFieldPresent = false;
uint8_t Fields[4] = {0x0, 0x0, 0x0, 0x0};
struct CIEInformation {
CIEInformation() = default;
CIEInformation(Symbol &CIESymbol) : CIESymbol(&CIESymbol) {}
Symbol *CIESymbol = nullptr;
bool FDEsHaveLSDAField = false;
uint8_t FDEPointerEncoding = 0;
uint8_t LSDAPointerEncoding = 0;
struct EdgeTarget {
EdgeTarget() = default;
EdgeTarget(const Edge &E) : Target(&E.getTarget()), Addend(E.getAddend()) {}
Symbol *Target = nullptr;
Edge::AddendT Addend = 0;
using BlockEdgeMap = DenseMap<Edge::OffsetT, EdgeTarget>;
using CIEInfosMap = DenseMap<JITTargetAddress, CIEInformation>;
struct ParseContext {
ParseContext(LinkGraph &G) : G(G) {}
Expected<CIEInformation *> findCIEInfo(JITTargetAddress Address) {
auto I = CIEInfos.find(Address);
if (I == CIEInfos.end())
return make_error<JITLinkError>("No CIE found at address " +
formatv("{0:x16}", Address));
return &I->second;
LinkGraph &G;
CIEInfosMap CIEInfos;
BlockAddressMap AddrToBlock;
SymbolAddressMap AddrToSyms;
Error processBlock(ParseContext &PC, Block &B);
Error processCIE(ParseContext &PC, Block &B, size_t RecordOffset,
size_t RecordLength, size_t CIEDeltaFieldOffset);
Error processFDE(ParseContext &PC, Block &B, size_t RecordOffset,
size_t RecordLength, size_t CIEDeltaFieldOffset,
uint32_t CIEDelta, BlockEdgeMap &BlockEdges);
parseAugmentationString(BinaryStreamReader &RecordReader);
static bool isSupportedPointerEncoding(uint8_t PointerEncoding);
unsigned getPointerEncodingDataSize(uint8_t PointerEncoding);
Expected<std::pair<JITTargetAddress, Edge::Kind>>
readEncodedPointer(uint8_t PointerEncoding,
JITTargetAddress PointerFieldAddress,
BinaryStreamReader &RecordReader);
Expected<Symbol &> getOrCreateSymbol(ParseContext &PC, JITTargetAddress Addr);
StringRef EHFrameSectionName;
unsigned PointerSize;
Edge::Kind Delta64;
Edge::Kind Delta32;
Edge::Kind NegDelta32;
/// Add a 32-bit null-terminator to the end of the eh-frame section.
class EHFrameNullTerminator {
EHFrameNullTerminator(StringRef EHFrameSectionName);
Error operator()(LinkGraph &G);
static char NullTerminatorBlockContent[];
StringRef EHFrameSectionName;
} // end namespace jitlink
} // end namespace llvm