1 //===-- DWARFFormValue.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_DWARFFORMVALUE_H 11 #define LLVM_DEBUGINFO_DWARFFORMVALUE_H 12 13 #include "llvm/ADT/Optional.h" 14 #include "llvm/Support/DataExtractor.h" 15 16 namespace llvm { 17 18 template <typename T> class ArrayRef; 19 class DWARFUnit; 20 class raw_ostream; 21 22 class DWARFFormValue { 23 public: 24 enum FormClass { 25 FC_Unknown, 26 FC_Address, 27 FC_Block, 28 FC_Constant, 29 FC_String, 30 FC_Flag, 31 FC_Reference, 32 FC_Indirect, 33 FC_SectionOffset, 34 FC_Exprloc 35 }; 36 37 private: 38 struct ValueType { 39 ValueType() : data(nullptr) { 40 uval = 0; 41 } 42 43 union { 44 uint64_t uval; 45 int64_t sval; 46 const char* cstr; 47 }; 48 const uint8_t* data; 49 }; 50 51 uint16_t Form; // Form for this value. 52 ValueType Value; // Contains all data for the form. 53 54 public: 55 DWARFFormValue(uint16_t Form = 0) : Form(Form) {} 56 uint16_t getForm() const { return Form; } 57 bool isFormClass(FormClass FC) const; 58 59 void dump(raw_ostream &OS, const DWARFUnit *U) const; 60 61 /// \brief extracts a value in data at offset *offset_ptr. 62 /// 63 /// The passed DWARFUnit is allowed to be nullptr, in which 64 /// case no relocation processing will be performed and some 65 /// kind of forms that depend on Unit information are disallowed. 66 /// \returns whether the extraction succeeded. 67 bool extractValue(DataExtractor data, uint32_t *offset_ptr, 68 const DWARFUnit *u); 69 bool isInlinedCStr() const { 70 return Value.data != nullptr && Value.data == (const uint8_t*)Value.cstr; 71 } 72 73 /// getAsFoo functions below return the extracted value as Foo if only 74 /// DWARFFormValue has form class is suitable for representing Foo. 75 Optional<uint64_t> getAsReference(const DWARFUnit *U) const; 76 Optional<uint64_t> getAsUnsignedConstant() const; 77 Optional<int64_t> getAsSignedConstant() const; 78 Optional<const char *> getAsCString(const DWARFUnit *U) const; 79 Optional<uint64_t> getAsAddress(const DWARFUnit *U) const; 80 Optional<uint64_t> getAsSectionOffset() const; 81 Optional<ArrayRef<uint8_t>> getAsBlock() const; 82 83 bool skipValue(DataExtractor debug_info_data, uint32_t *offset_ptr, 84 const DWARFUnit *u) const; 85 static bool skipValue(uint16_t form, DataExtractor debug_info_data, 86 uint32_t *offset_ptr, const DWARFUnit *u); 87 static bool skipValue(uint16_t form, DataExtractor debug_info_data, 88 uint32_t *offset_ptr, uint16_t Version, 89 uint8_t AddrSize); 90 91 static ArrayRef<uint8_t> getFixedFormSizes(uint8_t AddrSize, 92 uint16_t Version); 93 private: 94 void dumpString(raw_ostream &OS, const DWARFUnit *U) const; 95 }; 96 97 } 98 99 #endif 100
