1 //===-- DWARFCallFrameInfo.h ------------------------------------*- 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 #ifndef LLDB_SYMBOL_DWARFCALLFRAMEINFO_H 10 #define LLDB_SYMBOL_DWARFCALLFRAMEINFO_H 11 12 #include <map> 13 #include <mutex> 14 15 #include "lldb/Core/AddressRange.h" 16 #include "lldb/Core/dwarf.h" 17 #include "lldb/Symbol/ObjectFile.h" 18 #include "lldb/Symbol/UnwindPlan.h" 19 #include "lldb/Utility/Flags.h" 20 #include "lldb/Utility/RangeMap.h" 21 #include "lldb/Utility/VMRange.h" 22 #include "lldb/lldb-private.h" 23 24 namespace lldb_private { 25 26 // DWARFCallFrameInfo is a class which can read eh_frame and DWARF Call Frame 27 // Information FDEs. It stores little information internally. Only two APIs 28 // are exported - one to find the high/low pc values of a function given a text 29 // address via the information in the eh_frame / debug_frame, and one to 30 // generate an UnwindPlan based on the FDE in the eh_frame / debug_frame 31 // section. 32 33 class DWARFCallFrameInfo { 34 public: 35 enum Type { EH, DWARF }; 36 37 DWARFCallFrameInfo(ObjectFile &objfile, lldb::SectionSP §ion, Type type); 38 39 ~DWARFCallFrameInfo() = default; 40 41 // Locate an AddressRange that includes the provided Address in this object's 42 // eh_frame/debug_info Returns true if a range is found to cover that 43 // address. 44 bool GetAddressRange(Address addr, AddressRange &range); 45 46 /// Return an UnwindPlan based on the call frame information encoded in the 47 /// FDE of this DWARFCallFrameInfo section. The returned plan will be valid 48 /// (at least) for the given address. 49 bool GetUnwindPlan(const Address &addr, UnwindPlan &unwind_plan); 50 51 /// Return an UnwindPlan based on the call frame information encoded in the 52 /// FDE of this DWARFCallFrameInfo section. The returned plan will be valid 53 /// (at least) for some address in the given range. 54 bool GetUnwindPlan(const AddressRange &range, UnwindPlan &unwind_plan); 55 56 typedef RangeVector<lldb::addr_t, uint32_t> FunctionAddressAndSizeVector; 57 58 // Build a vector of file address and size for all functions in this Module 59 // based on the eh_frame FDE entries. 60 // 61 // The eh_frame information can be a useful source of file address and size 62 // of the functions in a Module. Often a binary's non-exported symbols are 63 // stripped before shipping so lldb won't know the start addr / size of many 64 // functions in the Module. But the eh_frame can help to give the addresses 65 // of these stripped symbols, at least. 66 // 67 // \param[out] function_info 68 // A vector provided by the caller is filled out. May be empty if no 69 // FDEs/no eh_frame 70 // is present in this Module. 71 72 void 73 GetFunctionAddressAndSizeVector(FunctionAddressAndSizeVector &function_info); 74 75 void ForEachFDEEntries( 76 const std::function<bool(lldb::addr_t, uint32_t, dw_offset_t)> &callback); 77 78 private: 79 enum { CFI_AUG_MAX_SIZE = 8, CFI_HEADER_SIZE = 8 }; 80 enum CFIVersion { 81 CFI_VERSION1 = 1, // DWARF v.2 82 CFI_VERSION3 = 3, // DWARF v.3 83 CFI_VERSION4 = 4 // DWARF v.4, v.5 84 }; 85 86 struct CIE { 87 dw_offset_t cie_offset; 88 uint8_t version; 89 char augmentation[CFI_AUG_MAX_SIZE]; // This is typically empty or very 90 // short. 91 uint8_t address_size = sizeof(uint32_t); // The size of a target address. 92 uint8_t segment_size = 0; // The size of a segment selector. 93 94 uint32_t code_align; 95 int32_t data_align; 96 uint32_t return_addr_reg_num; 97 dw_offset_t inst_offset; // offset of CIE instructions in mCFIData 98 uint32_t inst_length; // length of CIE instructions in mCFIData 99 uint8_t ptr_encoding; 100 uint8_t lsda_addr_encoding; // The encoding of the LSDA address in the FDE 101 // augmentation data 102 lldb::addr_t personality_loc; // (file) address of the pointer to the 103 // personality routine 104 lldb_private::UnwindPlan::Row initial_row; 105 CIECIE106 CIE(dw_offset_t offset) 107 : cie_offset(offset), version(-1), code_align(0), data_align(0), 108 return_addr_reg_num(LLDB_INVALID_REGNUM), inst_offset(0), 109 inst_length(0), ptr_encoding(0), lsda_addr_encoding(DW_EH_PE_omit), 110 personality_loc(LLDB_INVALID_ADDRESS), initial_row() {} 111 }; 112 113 typedef std::shared_ptr<CIE> CIESP; 114 115 typedef std::map<dw_offset_t, CIESP> cie_map_t; 116 117 // Start address (file address), size, offset of FDE location used for 118 // finding an FDE for a given File address; the start address field is an 119 // offset into an individual Module. 120 typedef RangeDataVector<lldb::addr_t, uint32_t, dw_offset_t> FDEEntryMap; 121 122 bool IsEHFrame() const; 123 124 llvm::Optional<FDEEntryMap::Entry> 125 GetFirstFDEEntryInRange(const AddressRange &range); 126 127 void GetFDEIndex(); 128 129 bool FDEToUnwindPlan(uint32_t offset, Address startaddr, 130 UnwindPlan &unwind_plan); 131 132 const CIE *GetCIE(dw_offset_t cie_offset); 133 134 void GetCFIData(); 135 136 // Applies the specified DWARF opcode to the given row. This function handle 137 // the commands operates only on a single row (these are the ones what can 138 // appear both in 139 // CIE and in FDE). 140 // Returns true if the opcode is handled and false otherwise. 141 bool HandleCommonDwarfOpcode(uint8_t primary_opcode, uint8_t extended_opcode, 142 int32_t data_align, lldb::offset_t &offset, 143 UnwindPlan::Row &row); 144 145 ObjectFile &m_objfile; 146 lldb::SectionSP m_section_sp; 147 Flags m_flags = 0; 148 cie_map_t m_cie_map; 149 150 DataExtractor m_cfi_data; 151 bool m_cfi_data_initialized = false; // only copy the section into the DE once 152 153 FDEEntryMap m_fde_index; 154 bool m_fde_index_initialized = false; // only scan the section for FDEs once 155 std::mutex m_fde_index_mutex; // and isolate the thread that does it 156 157 Type m_type; 158 159 CIESP 160 ParseCIE(const uint32_t cie_offset); 161 GetRegisterKind()162 lldb::RegisterKind GetRegisterKind() const { 163 return m_type == EH ? lldb::eRegisterKindEHFrame : lldb::eRegisterKindDWARF; 164 } 165 }; 166 167 } // namespace lldb_private 168 169 #endif // LLDB_SYMBOL_DWARFCALLFRAMEINFO_H 170