1 //==- llvm/CodeGen/TargetLoweringObjectFileImpl.h - Object Info --*- 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 // This file implements classes used to handle lowerings specific to common 10 // object file formats. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H 15 #define LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H 16 17 #include "llvm/ADT/SmallPtrSet.h" 18 #include "llvm/BinaryFormat/XCOFF.h" 19 #include "llvm/MC/MCExpr.h" 20 #include "llvm/Target/TargetLoweringObjectFile.h" 21 22 namespace llvm { 23 24 class GlobalValue; 25 class MachineModuleInfo; 26 class MachineFunction; 27 class MCContext; 28 class MCExpr; 29 class MCSection; 30 class MCSymbol; 31 class Module; 32 class TargetMachine; 33 34 class TargetLoweringObjectFileELF : public TargetLoweringObjectFile { 35 bool UseInitArray = false; 36 mutable unsigned NextUniqueID = 1; // ID 0 is reserved for execute-only sections 37 SmallPtrSet<GlobalObject *, 2> Used; 38 39 protected: 40 MCSymbolRefExpr::VariantKind PLTRelativeVariantKind = 41 MCSymbolRefExpr::VK_None; 42 43 public: 44 TargetLoweringObjectFileELF(); 45 ~TargetLoweringObjectFileELF() override = default; 46 47 void Initialize(MCContext &Ctx, const TargetMachine &TM) override; 48 49 void getModuleMetadata(Module &M) override; 50 51 /// Emit Obj-C garbage collection and linker options. 52 void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override; 53 54 void emitPersonalityValue(MCStreamer &Streamer, const DataLayout &DL, 55 const MCSymbol *Sym) const override; 56 57 /// Given a constant with the SectionKind, return a section that it should be 58 /// placed in. 59 MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind, 60 const Constant *C, 61 Align &Alignment) const override; 62 63 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 64 const TargetMachine &TM) const override; 65 66 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 67 const TargetMachine &TM) const override; 68 69 MCSection *getSectionForJumpTable(const Function &F, 70 const TargetMachine &TM) const override; 71 MCSection *getSectionForLSDA(const Function &F, const MCSymbol &FnSym, 72 const TargetMachine &TM) const override; 73 74 MCSection * 75 getSectionForMachineBasicBlock(const Function &F, 76 const MachineBasicBlock &MBB, 77 const TargetMachine &TM) const override; 78 79 MCSection * 80 getUniqueSectionForFunction(const Function &F, 81 const TargetMachine &TM) const override; 82 83 bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference, 84 const Function &F) const override; 85 86 /// Return an MCExpr to use for a reference to the specified type info global 87 /// variable from exception handling information. 88 const MCExpr *getTTypeGlobalReference(const GlobalValue *GV, 89 unsigned Encoding, 90 const TargetMachine &TM, 91 MachineModuleInfo *MMI, 92 MCStreamer &Streamer) const override; 93 94 // The symbol that gets passed to .cfi_personality. 95 MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV, 96 const TargetMachine &TM, 97 MachineModuleInfo *MMI) const override; 98 99 void InitializeELF(bool UseInitArray_); 100 MCSection *getStaticCtorSection(unsigned Priority, 101 const MCSymbol *KeySym) const override; 102 MCSection *getStaticDtorSection(unsigned Priority, 103 const MCSymbol *KeySym) const override; 104 105 const MCExpr *lowerRelativeReference(const GlobalValue *LHS, 106 const GlobalValue *RHS, 107 const TargetMachine &TM) const override; 108 109 const MCExpr *lowerDSOLocalEquivalent(const DSOLocalEquivalent *Equiv, 110 const TargetMachine &TM) const override; 111 112 MCSection *getSectionForCommandLines() const override; 113 }; 114 115 class TargetLoweringObjectFileMachO : public TargetLoweringObjectFile { 116 public: 117 TargetLoweringObjectFileMachO(); 118 ~TargetLoweringObjectFileMachO() override = default; 119 120 void Initialize(MCContext &Ctx, const TargetMachine &TM) override; 121 122 MCSection *getStaticDtorSection(unsigned Priority, 123 const MCSymbol *KeySym) const override; 124 125 /// Emit the module flags that specify the garbage collection information. 126 void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override; 127 128 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 129 const TargetMachine &TM) const override; 130 131 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 132 const TargetMachine &TM) const override; 133 134 MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind, 135 const Constant *C, 136 Align &Alignment) const override; 137 138 /// The mach-o version of this method defaults to returning a stub reference. 139 const MCExpr *getTTypeGlobalReference(const GlobalValue *GV, 140 unsigned Encoding, 141 const TargetMachine &TM, 142 MachineModuleInfo *MMI, 143 MCStreamer &Streamer) const override; 144 145 // The symbol that gets passed to .cfi_personality. 146 MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV, 147 const TargetMachine &TM, 148 MachineModuleInfo *MMI) const override; 149 150 /// Get MachO PC relative GOT entry relocation 151 const MCExpr *getIndirectSymViaGOTPCRel(const GlobalValue *GV, 152 const MCSymbol *Sym, 153 const MCValue &MV, int64_t Offset, 154 MachineModuleInfo *MMI, 155 MCStreamer &Streamer) const override; 156 157 void getNameWithPrefix(SmallVectorImpl<char> &OutName, const GlobalValue *GV, 158 const TargetMachine &TM) const override; 159 160 MCSection *getSectionForCommandLines() const override; 161 }; 162 163 class TargetLoweringObjectFileCOFF : public TargetLoweringObjectFile { 164 mutable unsigned NextUniqueID = 0; 165 const TargetMachine *TM = nullptr; 166 167 public: 168 ~TargetLoweringObjectFileCOFF() override = default; 169 170 void Initialize(MCContext &Ctx, const TargetMachine &TM) override; 171 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 172 const TargetMachine &TM) const override; 173 174 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 175 const TargetMachine &TM) const override; 176 177 void getNameWithPrefix(SmallVectorImpl<char> &OutName, const GlobalValue *GV, 178 const TargetMachine &TM) const override; 179 180 MCSection *getSectionForJumpTable(const Function &F, 181 const TargetMachine &TM) const override; 182 183 bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference, 184 const Function &F) const override; 185 186 /// Emit Obj-C garbage collection and linker options. 187 void emitModuleMetadata(MCStreamer &Streamer, Module &M) const override; 188 189 MCSection *getStaticCtorSection(unsigned Priority, 190 const MCSymbol *KeySym) const override; 191 MCSection *getStaticDtorSection(unsigned Priority, 192 const MCSymbol *KeySym) const override; 193 194 const MCExpr *lowerRelativeReference(const GlobalValue *LHS, 195 const GlobalValue *RHS, 196 const TargetMachine &TM) const override; 197 198 /// Given a mergeable constant with the specified size and relocation 199 /// information, return a section that it should be placed in. 200 MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind, 201 const Constant *C, 202 Align &Alignment) const override; 203 204 private: 205 void emitLinkerDirectives(MCStreamer &Streamer, Module &M) const; 206 }; 207 208 class TargetLoweringObjectFileWasm : public TargetLoweringObjectFile { 209 mutable unsigned NextUniqueID = 0; 210 211 public: 212 TargetLoweringObjectFileWasm() = default; 213 ~TargetLoweringObjectFileWasm() override = default; 214 215 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 216 const TargetMachine &TM) const override; 217 218 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 219 const TargetMachine &TM) const override; 220 221 bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference, 222 const Function &F) const override; 223 224 void InitializeWasm(); 225 MCSection *getStaticCtorSection(unsigned Priority, 226 const MCSymbol *KeySym) const override; 227 MCSection *getStaticDtorSection(unsigned Priority, 228 const MCSymbol *KeySym) const override; 229 230 const MCExpr *lowerRelativeReference(const GlobalValue *LHS, 231 const GlobalValue *RHS, 232 const TargetMachine &TM) const override; 233 }; 234 235 class TargetLoweringObjectFileXCOFF : public TargetLoweringObjectFile { 236 public: 237 TargetLoweringObjectFileXCOFF() = default; 238 ~TargetLoweringObjectFileXCOFF() override = default; 239 240 static bool ShouldEmitEHBlock(const MachineFunction *MF); 241 static bool ShouldSetSSPCanaryBitInTB(const MachineFunction *MF); 242 243 static MCSymbol *getEHInfoTableSymbol(const MachineFunction *MF); 244 245 void Initialize(MCContext &Ctx, const TargetMachine &TM) override; 246 247 bool shouldPutJumpTableInFunctionSection(bool UsesLabelDifference, 248 const Function &F) const override; 249 250 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 251 const TargetMachine &TM) const override; 252 253 MCSection *getStaticCtorSection(unsigned Priority, 254 const MCSymbol *KeySym) const override; 255 MCSection *getStaticDtorSection(unsigned Priority, 256 const MCSymbol *KeySym) const override; 257 258 const MCExpr *lowerRelativeReference(const GlobalValue *LHS, 259 const GlobalValue *RHS, 260 const TargetMachine &TM) const override; 261 262 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 263 const TargetMachine &TM) const override; 264 265 MCSection *getSectionForJumpTable(const Function &F, 266 const TargetMachine &TM) const override; 267 268 /// Given a constant with the SectionKind, return a section that it should be 269 /// placed in. 270 MCSection *getSectionForConstant(const DataLayout &DL, SectionKind Kind, 271 const Constant *C, 272 Align &Alignment) const override; 273 274 static XCOFF::StorageClass getStorageClassForGlobal(const GlobalValue *GV); 275 276 MCSection * 277 getSectionForFunctionDescriptor(const Function *F, 278 const TargetMachine &TM) const override; 279 MCSection *getSectionForTOCEntry(const MCSymbol *Sym, 280 const TargetMachine &TM) const override; 281 282 /// For external functions, this will always return a function descriptor 283 /// csect. 284 MCSection * 285 getSectionForExternalReference(const GlobalObject *GO, 286 const TargetMachine &TM) const override; 287 288 /// For functions, this will always return a function descriptor symbol. 289 MCSymbol *getTargetSymbol(const GlobalValue *GV, 290 const TargetMachine &TM) const override; 291 292 MCSymbol *getFunctionEntryPointSymbol(const GlobalValue *Func, 293 const TargetMachine &TM) const override; 294 295 /// For functions, this will return the LSDA section. If option 296 /// -ffunction-sections is on, this will return a unique csect with the 297 /// function name appended to .gcc_except_table as a suffix of the LSDA 298 /// section name. 299 MCSection *getSectionForLSDA(const Function &F, const MCSymbol &FnSym, 300 const TargetMachine &TM) const override; 301 }; 302 303 class TargetLoweringObjectFileGOFF : public TargetLoweringObjectFile { 304 public: 305 TargetLoweringObjectFileGOFF(); 306 ~TargetLoweringObjectFileGOFF() override = default; 307 308 MCSection *SelectSectionForGlobal(const GlobalObject *GO, SectionKind Kind, 309 const TargetMachine &TM) const override; 310 MCSection *getExplicitSectionGlobal(const GlobalObject *GO, SectionKind Kind, 311 const TargetMachine &TM) const override; 312 }; 313 314 } // end namespace llvm 315 316 #endif // LLVM_CODEGEN_TARGETLOWERINGOBJECTFILEIMPL_H 317