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_WeakrefUsedInReloc_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 (isWeakrefUsedInReloc()) 88 return ELF::STB_WEAK; 89 if (isSignature()) 90 return ELF::STB_LOCAL; 91 return ELF::STB_GLOBAL; 92 } 93 94 void MCSymbolELF::setType(unsigned Type) const { 95 unsigned Val; 96 switch (Type) { 97 default: 98 llvm_unreachable("Unsupported Binding"); 99 case ELF::STT_NOTYPE: 100 Val = 0; 101 break; 102 case ELF::STT_OBJECT: 103 Val = 1; 104 break; 105 case ELF::STT_FUNC: 106 Val = 2; 107 break; 108 case ELF::STT_SECTION: 109 Val = 3; 110 break; 111 case ELF::STT_COMMON: 112 Val = 4; 113 break; 114 case ELF::STT_TLS: 115 Val = 5; 116 break; 117 case ELF::STT_GNU_IFUNC: 118 Val = 6; 119 break; 120 } 121 uint32_t OtherFlags = getFlags() & ~(0x7 << ELF_STT_Shift); 122 setFlags(OtherFlags | (Val << ELF_STT_Shift)); 123 } 124 125 unsigned MCSymbolELF::getType() const { 126 uint32_t Val = (Flags >> ELF_STT_Shift) & 7; 127 switch (Val) { 128 default: 129 llvm_unreachable("Invalid value"); 130 case 0: 131 return ELF::STT_NOTYPE; 132 case 1: 133 return ELF::STT_OBJECT; 134 case 2: 135 return ELF::STT_FUNC; 136 case 3: 137 return ELF::STT_SECTION; 138 case 4: 139 return ELF::STT_COMMON; 140 case 5: 141 return ELF::STT_TLS; 142 case 6: 143 return ELF::STT_GNU_IFUNC; 144 } 145 } 146 147 void MCSymbolELF::setVisibility(unsigned Visibility) { 148 assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL || 149 Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED); 150 151 uint32_t OtherFlags = getFlags() & ~(0x3 << ELF_STV_Shift); 152 setFlags(OtherFlags | (Visibility << ELF_STV_Shift)); 153 } 154 155 unsigned MCSymbolELF::getVisibility() const { 156 unsigned Visibility = (Flags >> ELF_STV_Shift) & 3; 157 return Visibility; 158 } 159 160 void MCSymbolELF::setOther(unsigned Other) { 161 assert((Other & 0x1f) == 0); 162 Other >>= 5; 163 assert(Other <= 0x7); 164 uint32_t OtherFlags = getFlags() & ~(0x7 << ELF_STO_Shift); 165 setFlags(OtherFlags | (Other << ELF_STO_Shift)); 166 } 167 168 unsigned MCSymbolELF::getOther() const { 169 unsigned Other = (Flags >> ELF_STO_Shift) & 7; 170 return Other << 5; 171 } 172 173 void MCSymbolELF::setIsWeakrefUsedInReloc() const { 174 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_WeakrefUsedInReloc_Shift); 175 setFlags(OtherFlags | (1 << ELF_WeakrefUsedInReloc_Shift)); 176 } 177 178 bool MCSymbolELF::isWeakrefUsedInReloc() const { 179 return getFlags() & (0x1 << ELF_WeakrefUsedInReloc_Shift); 180 } 181 182 void MCSymbolELF::setIsSignature() const { 183 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_IsSignature_Shift); 184 setFlags(OtherFlags | (1 << ELF_IsSignature_Shift)); 185 } 186 187 bool MCSymbolELF::isSignature() const { 188 return getFlags() & (0x1 << ELF_IsSignature_Shift); 189 } 190 191 void MCSymbolELF::setIsBindingSet() const { 192 uint32_t OtherFlags = getFlags() & ~(0x1 << ELF_BindingSet_Shift); 193 setFlags(OtherFlags | (1 << ELF_BindingSet_Shift)); 194 } 195 196 bool MCSymbolELF::isBindingSet() const { 197 return getFlags() & (0x1 << ELF_BindingSet_Shift); 198 } 199 200 bool MCSymbolELF::isMemtag() const { 201 return getFlags() & (0x1 << ELF_IsMemoryTagged_Shift); 202 } 203 204 void MCSymbolELF::setMemtag(bool Tagged) { 205 uint32_t OtherFlags = getFlags() & ~(1 << ELF_IsMemoryTagged_Shift); 206 if (Tagged) 207 setFlags(OtherFlags | (1 << ELF_IsMemoryTagged_Shift)); 208 else 209 setFlags(OtherFlags); 210 } 211 } 212