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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===- DWARFDataExtractor.h -------------------------------------*- C++ -*-===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |||
| 9 | #ifndef LLVM_DEBUGINFO_DWARF_DWARFDATAEXTRACTOR_H |
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| 10 | #define LLVM_DEBUGINFO_DWARF_DWARFDATAEXTRACTOR_H |
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| 11 | |||
| 12 | #include "llvm/BinaryFormat/Dwarf.h" |
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| 13 | #include "llvm/DebugInfo/DWARF/DWARFSection.h" |
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| 14 | #include "llvm/Support/DataExtractor.h" |
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| 15 | |||
| 16 | namespace llvm { |
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| 17 | class DWARFObject; |
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| 18 | |||
| 19 | /// A DataExtractor (typically for an in-memory copy of an object-file section) |
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| 20 | /// plus a relocation map for that section, if there is one. |
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| 21 | class DWARFDataExtractor : public DataExtractor { |
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| 22 | const DWARFObject *Obj = nullptr; |
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| 23 | const DWARFSection *Section = nullptr; |
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| 24 | |||
| 25 | public: |
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| 26 | /// Constructor for the normal case of extracting data from a DWARF section. |
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| 27 | /// The DWARFSection's lifetime must be at least as long as the extractor's. |
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| 28 | DWARFDataExtractor(const DWARFObject &Obj, const DWARFSection &Section, |
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| 29 | bool IsLittleEndian, uint8_t AddressSize) |
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| 30 | : DataExtractor(Section.Data, IsLittleEndian, AddressSize), Obj(&Obj), |
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| 31 | Section(&Section) {} |
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| 32 | |||
| 33 | /// Constructor for cases when there are no relocations. |
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| 34 | DWARFDataExtractor(StringRef Data, bool IsLittleEndian, uint8_t AddressSize) |
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| 35 | : DataExtractor(Data, IsLittleEndian, AddressSize) {} |
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| 36 | DWARFDataExtractor(ArrayRef<uint8_t> Data, bool IsLittleEndian, |
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| 37 | uint8_t AddressSize) |
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| 38 | : DataExtractor( |
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| 39 | StringRef(reinterpret_cast<const char *>(Data.data()), Data.size()), |
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| 40 | IsLittleEndian, AddressSize) {} |
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| 41 | |||
| 42 | /// Truncating constructor |
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| 43 | DWARFDataExtractor(const DWARFDataExtractor &Other, size_t Length) |
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| 44 | : DataExtractor(Other.getData().substr(0, Length), Other.isLittleEndian(), |
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| 45 | Other.getAddressSize()), |
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| 46 | Obj(Other.Obj), Section(Other.Section) {} |
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| 47 | |||
| 48 | /// Extracts the DWARF "initial length" field, which can either be a 32-bit |
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| 49 | /// value smaller than 0xfffffff0, or the value 0xffffffff followed by a |
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| 50 | /// 64-bit length. Returns the actual length, and the DWARF format which is |
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| 51 | /// encoded in the field. In case of errors, it returns {0, DWARF32} and |
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| 52 | /// leaves the offset unchanged. |
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| 53 | std::pair<uint64_t, dwarf::DwarfFormat> |
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| 54 | getInitialLength(uint64_t *Off, Error *Err = nullptr) const; |
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| 55 | |||
| 56 | std::pair<uint64_t, dwarf::DwarfFormat> getInitialLength(Cursor &C) const { |
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| 57 | return getInitialLength(&getOffset(C), &getError(C)); |
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| 58 | } |
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| 59 | |||
| 60 | /// Extracts a value and applies a relocation to the result if |
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| 61 | /// one exists for the given offset. |
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| 62 | uint64_t getRelocatedValue(uint32_t Size, uint64_t *Off, |
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| 63 | uint64_t *SectionIndex = nullptr, |
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| 64 | Error *Err = nullptr) const; |
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| 65 | uint64_t getRelocatedValue(Cursor &C, uint32_t Size, |
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| 66 | uint64_t *SectionIndex = nullptr) const { |
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| 67 | return getRelocatedValue(Size, &getOffset(C), SectionIndex, &getError(C)); |
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| 68 | } |
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| 69 | |||
| 70 | /// Extracts an address-sized value and applies a relocation to the result if |
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| 71 | /// one exists for the given offset. |
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| 72 | uint64_t getRelocatedAddress(uint64_t *Off, uint64_t *SecIx = nullptr) const { |
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| 73 | return getRelocatedValue(getAddressSize(), Off, SecIx); |
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| 74 | } |
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| 75 | uint64_t getRelocatedAddress(Cursor &C, uint64_t *SecIx = nullptr) const { |
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| 76 | return getRelocatedValue(getAddressSize(), &getOffset(C), SecIx, |
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| 77 | &getError(C)); |
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| 78 | } |
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| 79 | |||
| 80 | /// Extracts a DWARF-encoded pointer in \p Offset using \p Encoding. |
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| 81 | /// There is a DWARF encoding that uses a PC-relative adjustment. |
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| 82 | /// For these values, \p AbsPosOffset is used to fix them, which should |
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| 83 | /// reflect the absolute address of this pointer. |
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| 84 | std::optional<uint64_t> getEncodedPointer(uint64_t *Offset, uint8_t Encoding, |
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| 85 | uint64_t AbsPosOffset = 0) const; |
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| 86 | }; |
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| 87 | |||
| 88 | } // end namespace llvm |
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| 89 | |||
| 90 | #endif // LLVM_DEBUGINFO_DWARF_DWARFDATAEXTRACTOR_H |