1 //===- InlineInfo.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 LLVM_DEBUGINFO_GSYM_INLINEINFO_H 10 #define LLVM_DEBUGINFO_GSYM_INLINEINFO_H 11 12 #include "llvm/DebugInfo/GSYM/ExtractRanges.h" 13 #include "llvm/DebugInfo/GSYM/LineEntry.h" 14 #include "llvm/DebugInfo/GSYM/LookupResult.h" 15 #include "llvm/Support/Error.h" 16 #include <stdint.h> 17 #include <vector> 18 19 namespace llvm { 20 class raw_ostream; 21 22 namespace gsym { 23 24 class GsymReader; 25 /// Inline information stores the name of the inline function along with 26 /// an array of address ranges. It also stores the call file and call line 27 /// that called this inline function. This allows us to unwind inline call 28 /// stacks back to the inline or concrete function that called this 29 /// function. Inlined functions contained in this function are stored in the 30 /// "Children" variable. All address ranges must be sorted and all address 31 /// ranges of all children must be contained in the ranges of this function. 32 /// Any clients that encode information will need to ensure the ranges are 33 /// all contined correctly or lookups could fail. Add ranges in these objects 34 /// must be contained in the top level FunctionInfo address ranges as well. 35 /// 36 /// ENCODING 37 /// 38 /// When saved to disk, the inline info encodes all ranges to be relative to 39 /// a parent address range. This will be the FunctionInfo's start address if 40 /// the InlineInfo is directly contained in a FunctionInfo, or a the start 41 /// address of the containing parent InlineInfo's first "Ranges" member. This 42 /// allows address ranges to be efficiently encoded using ULEB128 encodings as 43 /// we encode the offset and size of each range instead of full addresses. This 44 /// also makes any encoded addresses easy to relocate as we just need to 45 /// relocate the FunctionInfo's start address. 46 /// 47 /// - The AddressRanges member "Ranges" is encoded using an appropriate base 48 /// address as described above. 49 /// - UINT8 boolean value that specifies if the InlineInfo object has children. 50 /// - UINT32 string table offset that points to the name of the inline 51 /// function. 52 /// - ULEB128 integer that specifies the file of the call site that called 53 /// this function. 54 /// - ULEB128 integer that specifies the source line of the call site that 55 /// called this function. 56 /// - if this object has children, enocode each child InlineInfo using the 57 /// the first address range's start address as the base address. 58 /// 59 struct InlineInfo { 60 61 uint32_t Name; ///< String table offset in the string table. 62 uint32_t CallFile; ///< 1 based file index in the file table. 63 uint32_t CallLine; ///< Source line number. 64 AddressRanges Ranges; 65 std::vector<InlineInfo> Children; 66 InlineInfo() : Name(0), CallFile(0), CallLine(0) {} 67 void clear() { 68 Name = 0; 69 CallFile = 0; 70 CallLine = 0; 71 Ranges.clear(); 72 Children.clear(); 73 } 74 bool isValid() const { return !Ranges.empty(); } 75 76 using InlineArray = std::vector<const InlineInfo *>; 77 78 /// Lookup a single address within the inline info data. 79 /// 80 /// Clients have the option to decode an entire InlineInfo object (using 81 /// InlineInfo::decode() ) or just find the matching inline info using this 82 /// function. The benefit of using this function is that only the information 83 /// needed for the lookup will be extracted, other info can be skipped and 84 /// parsing can stop as soon as the deepest match is found. This allows 85 /// symbolication tools to be fast and efficient and avoid allocation costs 86 /// when doing lookups. 87 /// 88 /// This function will augment the SourceLocations array \a SrcLocs with any 89 /// inline information that pertains to \a Addr. If no inline information 90 /// exists for \a Addr, then \a SrcLocs will be left untouched. If there is 91 /// inline information for \a Addr, then \a SrcLocs will be modifiied to 92 /// contain the deepest most inline function's SourceLocation at index zero 93 /// in the array and proceed up the concrete function source file and 94 /// line at the end of the array. 95 /// 96 /// \param GR The GSYM reader that contains the string and file table that 97 /// will be used to fill in the source locations. 98 /// 99 /// \param Data The binary stream to read the data from. This object must 100 /// have the data for the LineTable object starting at offset zero. The data 101 /// can contain more data than needed. 102 /// 103 /// \param BaseAddr The base address to use when decoding the line table. 104 /// This will be the FunctionInfo's start address and will be used to 105 /// decode the correct addresses for the inline information. 106 /// 107 /// \param Addr The address to lookup. 108 /// 109 /// \param SrcLocs The inline source locations that matches \a Addr. This 110 /// array must be initialized with the matching line entry 111 /// from the line table upon entry. The name of the concrete 112 /// function must be supplied since it will get pushed to 113 /// the last SourceLocation entry and the inline information 114 /// will fill in the source file and line from the inline 115 /// information. 116 /// 117 /// \returns An error if the inline information is corrupt, or 118 /// Error::success() for all other cases, even when no information 119 /// is added to \a SrcLocs. 120 static llvm::Error lookup(const GsymReader &GR, DataExtractor &Data, 121 uint64_t BaseAddr, uint64_t Addr, 122 SourceLocations &SrcLocs); 123 124 /// Lookup an address in the InlineInfo object 125 /// 126 /// This function is used to symbolicate an inline call stack and can 127 /// turn one address in the program into one or more inline call stacks 128 /// and have the stack trace show the original call site from 129 /// non-inlined code. 130 /// 131 /// \param Addr the address to lookup 132 /// 133 /// \returns optional vector of InlineInfo objects that describe the 134 /// inline call stack for a given address, false otherwise. 135 std::optional<InlineArray> getInlineStack(uint64_t Addr) const; 136 137 /// Decode an InlineInfo object from a binary data stream. 138 /// 139 /// \param Data The binary stream to read the data from. This object must 140 /// have the data for the InlineInfo object starting at offset zero. The data 141 /// can contain more data than needed. 142 /// 143 /// \param BaseAddr The base address to use when decoding all address ranges. 144 /// This will be the FunctionInfo's start address if this object is directly 145 /// contained in a FunctionInfo object, or the start address of the first 146 /// address range in an InlineInfo object of this object is a child of 147 /// another InlineInfo object. 148 /// \returns An InlineInfo or an error describing the issue that was 149 /// encountered during decoding. 150 static llvm::Expected<InlineInfo> decode(DataExtractor &Data, 151 uint64_t BaseAddr); 152 153 /// Encode this InlineInfo object into FileWriter stream. 154 /// 155 /// \param O The binary stream to write the data to at the current file 156 /// position. 157 /// 158 /// \param BaseAddr The base address to use when encoding all address ranges. 159 /// This will be the FunctionInfo's start address if this object is directly 160 /// contained in a FunctionInfo object, or the start address of the first 161 /// address range in an InlineInfo object of this object is a child of 162 /// another InlineInfo object. 163 /// 164 /// \returns An error object that indicates success or failure or the 165 /// encoding process. 166 llvm::Error encode(FileWriter &O, uint64_t BaseAddr) const; 167 168 /// Compare InlineInfo objects. 169 /// 170 /// When comparing InlineInfo objects the item with the most inline functions 171 /// wins. If we have two FunctionInfo objects that both have the same address 172 /// range and both have valid InlineInfo objects, we want the one with the 173 /// most inline functions to win so we save the most information possible 174 /// to the GSYM file. We have seen cases where LTO messes up the inline 175 /// function information for the same address range, so this helps ensure we 176 /// get the most descriptive information we can for an address range. 177 bool operator<(const InlineInfo &RHS) const; 178 }; 179 180 inline bool operator==(const InlineInfo &LHS, const InlineInfo &RHS) { 181 return LHS.Name == RHS.Name && LHS.CallFile == RHS.CallFile && 182 LHS.CallLine == RHS.CallLine && LHS.Ranges == RHS.Ranges && 183 LHS.Children == RHS.Children; 184 } 185 186 raw_ostream &operator<<(raw_ostream &OS, const InlineInfo &FI); 187 188 } // namespace gsym 189 } // namespace llvm 190 191 #endif // LLVM_DEBUGINFO_GSYM_INLINEINFO_H 192