1 //===- lib/MC/MCSymbolELF.cpp ---------------------------------------------===// 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 #include "llvm/MC/MCSymbolELF.h" 10 #include "llvm/BinaryFormat/ELF.h" 11 12 namespace llvm { 13 14 namespace { 15 enum { 16 // Shift value for STT_* flags. 7 possible values. 3 bits. 17 ELF_STT_Shift = 0, 18 19 // Shift value for STB_* flags. 4 possible values, 2 bits. 20 ELF_STB_Shift = 3, 21 22 // Shift value for STV_* flags. 4 possible values, 2 bits. 23 ELF_STV_Shift = 5, 24 25 // Shift value for STO_* flags. 3 bits. All the values are between 0x20 and 26 // 0xe0, so we shift right by 5 before storing. 27 ELF_STO_Shift = 7, 28 29 // One bit. 30 ELF_IsSignature_Shift = 10, 31 32 // One bit. 33 ELF_Weakref_Shift = 11, 34 35 // One bit. 36 ELF_BindingSet_Shift = 12, 37 38 // One bit. 39 ELF_IsMemoryTagged_Shift = 13, 40 }; 41 } 42 43 void MCSymbolELF::setBinding(unsigned Binding) const { 44 setIsBindingSet(); 45 unsigned Val; 46 switch (Binding) { 47 default: 48 llvm_unreachable("Unsupported Binding"); 49 case ELF::STB_LOCAL: 50 Val = 0; 51 break; 52 case ELF::STB_GLOBAL: 53 Val = 1; 54 break; 55 case ELF::STB_WEAK: 56 Val = 2; 57 break; 58 case ELF::STB_GNU_UNIQUE: 59 Val = 3; 60 break; 61 } 62 uint32_t OtherFlags = getFlags() & ~(0x3 << ELF_STB_Shift); 63 setFlags(OtherFlags | (Val << ELF_STB_Shift)); 64 } 65 66 unsigned MCSymbolELF::getBinding() const { 67 if (isBindingSet()) { 68 uint32_t Val = (Flags >> ELF_STB_Shift) & 3; 69 switch (Val) { 70 default: 71 llvm_unreachable("Invalid value"); 72 case 0: 73 return ELF::STB_LOCAL; 74 case 1: 75 return ELF::STB_GLOBAL; 76 case 2: 77 return ELF::STB_WEAK; 78 case 3: 79 return ELF::STB_GNU_UNIQUE; 80 } 81 } 82 83 if (isDefined()) 84 return ELF::STB_LOCAL; 85 if (isUsedInReloc()) 86 return ELF::STB_GLOBAL; 87 if (isSignature()) 88 return ELF::STB_LOCAL; 89 return ELF::STB_GLOBAL; 90 } 91 92 void MCSymbolELF::setType(unsigned Type) const { 93 unsigned Val; 94 switch (Type) { 95 default: 96 llvm_unreachable("Unsupported Binding"); 97 case ELF::STT_NOTYPE: 98 Val = 0; 99 break; 100 case ELF::STT_OBJECT: 101 Val = 1; 102 break; 103 case ELF::STT_FUNC: 104 Val = 2; 105 break; 106 case ELF::STT_SECTION: 107 Val = 3; 108 break; 109 case ELF::STT_COMMON: 110 Val = 4; 111 break; 112 case ELF::STT_TLS: 113 Val = 5; 114 break; 115 case ELF::STT_GNU_IFUNC: 116 Val = 6; 117 break; 118 } 119 uint32_t OtherFlags = getFlags() & ~(0x7 << ELF_STT_Shift); 120 setFlags(OtherFlags | (Val << ELF_STT_Shift)); 121 } 122 123 unsigned MCSymbolELF::getType() const { 124 uint32_t Val = (Flags >> ELF_STT_Shift) & 7; 125 switch (Val) { 126 default: 127 llvm_unreachable("Invalid value"); 128 case 0: 129 return ELF::STT_NOTYPE; 130 case 1: 131 return ELF::STT_OBJECT; 132 case 2: 133 return ELF::STT_FUNC; 134 case 3: 135 return ELF::STT_SECTION; 136 case 4: 137 return ELF::STT_COMMON; 138 case 5: 139 return ELF::STT_TLS; 140 case 6: 141 return ELF::STT_GNU_IFUNC; 142 } 143 } 144 145 void MCSymbolELF::setVisibility(unsigned Visibility) { 146 assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL || 147 Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED); 148 149 uint32_t OtherFlags = getFlags() & ~(0x3 << ELF_STV_Shift); 150 setFlags(OtherFlags | (Visibility << ELF_STV_Shift)); 151 } 152 153 unsigned MCSymbolELF::getVisibility() const { 154 unsigned Visibility = (Flags >> ELF_STV_Shift) & 3; 155 return Visibility; 156 } 157 158 void MCSymbolELF::setOther(unsigned Other) { 159 assert((Other & 0x1f) == 0); 160 Other >>= 5; 161 assert(Other <= 0x7); 162 uint32_t OtherFlags = getFlags() & ~(0x7 << ELF_STO_Shift); 163 setFlags(OtherFlags | (Other << ELF_STO_Shift)); 164 } 165 166 unsigned MCSymbolELF::getOther() const { 167 unsigned Other = (Flags >> ELF_STO_Shift) & 7; 168 return Other << 5; 169 } 170 171 void MCSymbolELF::setIsWeakref() const { 172 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_Weakref_Shift); 173 setFlags(OtherFlags | (1 << ELF_Weakref_Shift)); 174 } 175 176 bool MCSymbolELF::isWeakref() const { 177 return getFlags() & (0x1 << ELF_Weakref_Shift); 178 } 179 180 void MCSymbolELF::setIsSignature() const { 181 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_IsSignature_Shift); 182 setFlags(OtherFlags | (1 << ELF_IsSignature_Shift)); 183 } 184 185 bool MCSymbolELF::isSignature() const { 186 return getFlags() & (0x1 << ELF_IsSignature_Shift); 187 } 188 189 void MCSymbolELF::setIsBindingSet() const { 190 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_BindingSet_Shift); 191 setFlags(OtherFlags | (1 << ELF_BindingSet_Shift)); 192 } 193 194 bool MCSymbolELF::isBindingSet() const { 195 return getFlags() & (0x1 << ELF_BindingSet_Shift); 196 } 197 198 bool MCSymbolELF::isMemtag() const { 199 return getFlags() & (0x1 << ELF_IsMemoryTagged_Shift); 200 } 201 202 void MCSymbolELF::setMemtag(bool Tagged) { 203 uint32_t OtherFlags = getFlags() & ~(1 << ELF_IsMemoryTagged_Shift); 204 if (Tagged) 205 setFlags(OtherFlags | (1 << ELF_IsMemoryTagged_Shift)); 206 else 207 setFlags(OtherFlags); 208 } 209 } 210