lib/ExecutionEngine/JITLink/EHFrameSupportImpl.h

   1 //===------- EHFrameSupportImpl.h - JITLink eh-frame utils ------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // EHFrame registration support for JITLink.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORTIMPL_H
  14 #define LLVM_LIB_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORTIMPL_H
  15
  16 #include "llvm/ExecutionEngine/JITLink/EHFrameSupport.h"
  17
  18 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
  19 #include "llvm/Support/BinaryStreamReader.h"
  20
  21 namespace llvm {
  22 namespace jitlink {
  23
  24 /// A generic binary parser for eh-frame sections.
  25 ///
  26 /// Adds blocks and symbols representing CIE and FDE entries to a JITLink graph.
  27 ///
  28 /// This parser assumes that the user has already verified that the EH-frame's
  29 /// address range does not overlap any other section/symbol, so that generated
  30 /// CIE/FDE records do not overlap other sections/symbols.
  31 class EHFrameBinaryParser {
  32 public:
  33   EHFrameBinaryParser(JITTargetAddress EHFrameAddress, StringRef EHFrameContent,
  34                       unsigned PointerSize, support::endianness Endianness);
  35   virtual ~EHFrameBinaryParser() {}
  36
  37   Error addToGraph();
  38
  39 private:
  40   virtual void anchor();
  41   virtual Symbol *getSymbolAtAddress(JITTargetAddress Addr) = 0;
  42   virtual Symbol &createCIERecord(JITTargetAddress RecordAddr,
  43                                   StringRef RecordContent) = 0;
  44   virtual Expected<Symbol &>
  45   createFDERecord(JITTargetAddress RecordAddr, StringRef RecordContent,
  46                   Symbol &CIE, size_t CIEOffset, Symbol &Func,
  47                   size_t FuncOffset, Symbol *LSDA, size_t LSDAOffset) = 0;
  48
  49   struct AugmentationInfo {
  50     bool AugmentationDataPresent = false;
  51     bool EHDataFieldPresent = false;
  52     uint8_t Fields[4] = {0x0, 0x0, 0x0, 0x0};
  53   };
  54
  55   Expected<AugmentationInfo> parseAugmentationString();
  56   Expected<JITTargetAddress> readAbsolutePointer();
  57   Error processCIE(size_t RecordOffset, size_t RecordLength);
  58   Error processFDE(size_t RecordOffset, size_t RecordLength,
  59                    JITTargetAddress CIEPointerOffset, uint32_t CIEPointer);
  60
  61   struct CIEInformation {
  62     CIEInformation() = default;
  63     CIEInformation(Symbol &CIESymbol) : CIESymbol(&CIESymbol) {}
  64     Symbol *CIESymbol = nullptr;
  65     bool FDEsHaveLSDAField = false;
  66   };
  67
  68   JITTargetAddress EHFrameAddress;
  69   StringRef EHFrameContent;
  70   unsigned PointerSize;
  71   BinaryStreamReader EHFrameReader;
  72   DenseMap<JITTargetAddress, CIEInformation> CIEInfos;
  73 };
  74
  75 } // end namespace jitlink
  76 } // end namespace llvm
  77
  78 #endif // LLVM_LIB_EXECUTIONENGINE_JITLINK_EHFRAMESUPPORTIMPL_H