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       1             : //===- DWARFDataExtractor.h -------------------------------------*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : 
      10             : #ifndef LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H
      11             : #define LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H
      12             : 
      13             : #include "llvm/DebugInfo/DWARF/DWARFSection.h"
      14             : #include "llvm/Support/DataExtractor.h"
      15             : 
      16             : namespace llvm {
      17             : class DWARFObject;
      18             : 
      19             : /// A DataExtractor (typically for an in-memory copy of an object-file section)
      20             : /// plus a relocation map for that section, if there is one.
      21             : class DWARFDataExtractor : public DataExtractor {
      22             :   const DWARFObject *Obj = nullptr;
      23             :   const DWARFSection *Section = nullptr;
      24             : 
      25             : public:
      26             :   /// Constructor for the normal case of extracting data from a DWARF section.
      27             :   /// The DWARFSection's lifetime must be at least as long as the extractor's.
      28             :   DWARFDataExtractor(const DWARFObject &Obj, const DWARFSection &Section,
      29             :                      bool IsLittleEndian, uint8_t AddressSize)
      30        8418 :       : DataExtractor(Section.Data, IsLittleEndian, AddressSize), Obj(&Obj),
      31        8321 :         Section(&Section) {}
      32             : 
      33             :   /// Constructor for cases when there are no relocations.
      34             :   DWARFDataExtractor(StringRef Data, bool IsLittleEndian, uint8_t AddressSize)
      35         378 :     : DataExtractor(Data, IsLittleEndian, AddressSize) {}
      36             : 
      37             :   /// Extracts a value and applies a relocation to the result if
      38             :   /// one exists for the given offset.
      39             :   uint64_t getRelocatedValue(uint32_t Size, uint32_t *Off,
      40             :                              uint64_t *SectionIndex = nullptr) const;
      41             : 
      42             :   /// Extracts an address-sized value and applies a relocation to the result if
      43             :   /// one exists for the given offset.
      44             :   uint64_t getRelocatedAddress(uint32_t *Off, uint64_t *SecIx = nullptr) const {
      45        9955 :     return getRelocatedValue(getAddressSize(), Off, SecIx);
      46             :   }
      47             : 
      48             :   /// Extracts a DWARF-encoded pointer in \p Offset using \p Encoding.
      49             :   /// There is a DWARF encoding that uses a PC-relative adjustment.
      50             :   /// For these values, \p AbsPosOffset is used to fix them, which should
      51             :   /// reflect the absolute address of this pointer.
      52             :   Optional<uint64_t> getEncodedPointer(uint32_t *Offset, uint8_t Encoding,
      53             :                                        uint64_t AbsPosOffset = 0) const;
      54             : 
      55          10 :   size_t size() const { return Section == nullptr ? 0 : Section->Data.size(); }
      56             : };
      57             : 
      58             : } // end namespace llvm
      59             : 
      60             : #endif // LLVM_DEBUGINFO_DWARFDATAEXTRACTOR_H