| 1 | //===-- Globals.cpp - Implement the GlobalValue & GlobalVariable class ----===// |
| 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 the GlobalValue & GlobalVariable classes for the IR |
| 10 | // library. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "LLVMContextImpl.h" |
| 15 | #include "llvm/IR/ConstantRange.h" |
| 16 | #include "llvm/IR/Constants.h" |
| 17 | #include "llvm/IR/DataLayout.h" |
| 18 | #include "llvm/IR/DerivedTypes.h" |
| 19 | #include "llvm/IR/GlobalAlias.h" |
| 20 | #include "llvm/IR/GlobalValue.h" |
| 21 | #include "llvm/IR/GlobalVariable.h" |
| 22 | #include "llvm/IR/MDBuilder.h" |
| 23 | #include "llvm/IR/Module.h" |
| 24 | #include "llvm/Support/Error.h" |
| 25 | #include "llvm/Support/ErrorHandling.h" |
| 26 | #include "llvm/Support/MD5.h" |
| 27 | #include "llvm/TargetParser/Triple.h" |
| 28 | using namespace llvm; |
| 29 | |
| 30 | //===----------------------------------------------------------------------===// |
| 31 | // GlobalValue Class |
| 32 | //===----------------------------------------------------------------------===// |
| 33 | |
| 34 | // GlobalValue should be a Constant, plus a type, a module, some flags, and an |
| 35 | // intrinsic ID. Add an assert to prevent people from accidentally growing |
| 36 | // GlobalValue while adding flags. |
| 37 | static_assert(sizeof(GlobalValue) == |
| 38 | sizeof(Constant) + 2 * sizeof(void *) + 2 * sizeof(unsigned), |
| 39 | "unexpected GlobalValue size growth" ); |
| 40 | |
| 41 | // GlobalObject adds a comdat. |
| 42 | static_assert(sizeof(GlobalObject) == sizeof(GlobalValue) + sizeof(void *), |
| 43 | "unexpected GlobalObject size growth" ); |
| 44 | |
| 45 | bool GlobalValue::isMaterializable() const { |
| 46 | if (const Function *F = dyn_cast<Function>(Val: this)) |
| 47 | return F->isMaterializable(); |
| 48 | return false; |
| 49 | } |
| 50 | Error GlobalValue::materialize() { return getParent()->materialize(GV: this); } |
| 51 | |
| 52 | /// Override destroyConstantImpl to make sure it doesn't get called on |
| 53 | /// GlobalValue's because they shouldn't be treated like other constants. |
| 54 | void GlobalValue::destroyConstantImpl() { |
| 55 | llvm_unreachable("You can't GV->destroyConstantImpl()!" ); |
| 56 | } |
| 57 | |
| 58 | Value *GlobalValue::handleOperandChangeImpl(Value *From, Value *To) { |
| 59 | llvm_unreachable("Unsupported class for handleOperandChange()!" ); |
| 60 | } |
| 61 | |
| 62 | /// copyAttributesFrom - copy all additional attributes (those not needed to |
| 63 | /// create a GlobalValue) from the GlobalValue Src to this one. |
| 64 | void GlobalValue::copyAttributesFrom(const GlobalValue *Src) { |
| 65 | setVisibility(Src->getVisibility()); |
| 66 | setUnnamedAddr(Src->getUnnamedAddr()); |
| 67 | setThreadLocalMode(Src->getThreadLocalMode()); |
| 68 | setDLLStorageClass(Src->getDLLStorageClass()); |
| 69 | setDSOLocal(Src->isDSOLocal()); |
| 70 | setPartition(Src->getPartition()); |
| 71 | if (Src->hasSanitizerMetadata()) |
| 72 | setSanitizerMetadata(Src->getSanitizerMetadata()); |
| 73 | else |
| 74 | removeSanitizerMetadata(); |
| 75 | } |
| 76 | |
| 77 | GlobalValue::GUID |
| 78 | GlobalValue::getGUIDAssumingExternalLinkage(StringRef GlobalIdentifier) { |
| 79 | return MD5Hash(Str: GlobalIdentifier); |
| 80 | } |
| 81 | |
| 82 | void GlobalValue::removeFromParent() { |
| 83 | switch (getValueID()) { |
| 84 | #define HANDLE_GLOBAL_VALUE(NAME) \ |
| 85 | case Value::NAME##Val: \ |
| 86 | return static_cast<NAME *>(this)->removeFromParent(); |
| 87 | #include "llvm/IR/Value.def" |
| 88 | default: |
| 89 | break; |
| 90 | } |
| 91 | llvm_unreachable("not a global" ); |
| 92 | } |
| 93 | |
| 94 | void GlobalValue::eraseFromParent() { |
| 95 | switch (getValueID()) { |
| 96 | #define HANDLE_GLOBAL_VALUE(NAME) \ |
| 97 | case Value::NAME##Val: \ |
| 98 | return static_cast<NAME *>(this)->eraseFromParent(); |
| 99 | #include "llvm/IR/Value.def" |
| 100 | default: |
| 101 | break; |
| 102 | } |
| 103 | llvm_unreachable("not a global" ); |
| 104 | } |
| 105 | |
| 106 | GlobalObject::~GlobalObject() { setComdat(nullptr); } |
| 107 | |
| 108 | bool GlobalValue::isInterposable() const { |
| 109 | if (isInterposableLinkage(Linkage: getLinkage())) |
| 110 | return true; |
| 111 | return getParent() && getParent()->getSemanticInterposition() && |
| 112 | !isDSOLocal(); |
| 113 | } |
| 114 | |
| 115 | bool GlobalValue::canBenefitFromLocalAlias() const { |
| 116 | if (isTagged()) { |
| 117 | // Cannot create local aliases to MTE tagged globals. The address of a |
| 118 | // tagged global includes a tag that is assigned by the loader in the |
| 119 | // GOT. |
| 120 | return false; |
| 121 | } |
| 122 | // See AsmPrinter::getSymbolPreferLocal(). For a deduplicate comdat kind, |
| 123 | // references to a discarded local symbol from outside the group are not |
| 124 | // allowed, so avoid the local alias. |
| 125 | auto isDeduplicateComdat = [](const Comdat *C) { |
| 126 | return C && C->getSelectionKind() != Comdat::NoDeduplicate; |
| 127 | }; |
| 128 | return hasDefaultVisibility() && |
| 129 | GlobalObject::isExternalLinkage(Linkage: getLinkage()) && !isDeclaration() && |
| 130 | !isa<GlobalIFunc>(Val: this) && !isDeduplicateComdat(getComdat()); |
| 131 | } |
| 132 | |
| 133 | const DataLayout &GlobalValue::getDataLayout() const { |
| 134 | return getParent()->getDataLayout(); |
| 135 | } |
| 136 | |
| 137 | void GlobalObject::setAlignment(MaybeAlign Align) { |
| 138 | assert((!Align || *Align <= MaximumAlignment) && |
| 139 | "Alignment is greater than MaximumAlignment!" ); |
| 140 | unsigned AlignmentData = encode(A: Align); |
| 141 | unsigned OldData = getGlobalValueSubClassData(); |
| 142 | setGlobalValueSubClassData((OldData & ~AlignmentMask) | AlignmentData); |
| 143 | assert(getAlign() == Align && "Alignment representation error!" ); |
| 144 | } |
| 145 | |
| 146 | void GlobalObject::setAlignment(Align Align) { |
| 147 | assert(Align <= MaximumAlignment && |
| 148 | "Alignment is greater than MaximumAlignment!" ); |
| 149 | unsigned AlignmentData = encode(A: Align); |
| 150 | unsigned OldData = getGlobalValueSubClassData(); |
| 151 | setGlobalValueSubClassData((OldData & ~AlignmentMask) | AlignmentData); |
| 152 | assert(getAlign() && *getAlign() == Align && |
| 153 | "Alignment representation error!" ); |
| 154 | } |
| 155 | |
| 156 | void GlobalObject::copyAttributesFrom(const GlobalObject *Src) { |
| 157 | GlobalValue::copyAttributesFrom(Src); |
| 158 | setAlignment(Src->getAlign()); |
| 159 | setSection(Src->getSection()); |
| 160 | } |
| 161 | |
| 162 | std::string GlobalValue::getGlobalIdentifier(StringRef Name, |
| 163 | GlobalValue::LinkageTypes Linkage, |
| 164 | StringRef FileName) { |
| 165 | // Value names may be prefixed with a binary '1' to indicate |
| 166 | // that the backend should not modify the symbols due to any platform |
| 167 | // naming convention. Do not include that '1' in the PGO profile name. |
| 168 | Name.consume_front(Prefix: "\1" ); |
| 169 | |
| 170 | std::string GlobalName; |
| 171 | if (llvm::GlobalValue::isLocalLinkage(Linkage)) { |
| 172 | // For local symbols, prepend the main file name to distinguish them. |
| 173 | // Do not include the full path in the file name since there's no guarantee |
| 174 | // that it will stay the same, e.g., if the files are checked out from |
| 175 | // version control in different locations. |
| 176 | if (FileName.empty()) |
| 177 | GlobalName += "<unknown>" ; |
| 178 | else |
| 179 | GlobalName += FileName; |
| 180 | |
| 181 | GlobalName += GlobalIdentifierDelimiter; |
| 182 | } |
| 183 | GlobalName += Name; |
| 184 | return GlobalName; |
| 185 | } |
| 186 | |
| 187 | std::string GlobalValue::getGlobalIdentifier() const { |
| 188 | return getGlobalIdentifier(Name: getName(), Linkage: getLinkage(), |
| 189 | FileName: getParent()->getSourceFileName()); |
| 190 | } |
| 191 | |
| 192 | StringRef GlobalValue::getSection() const { |
| 193 | if (auto *GA = dyn_cast<GlobalAlias>(Val: this)) { |
| 194 | // In general we cannot compute this at the IR level, but we try. |
| 195 | if (const GlobalObject *GO = GA->getAliaseeObject()) |
| 196 | return GO->getSection(); |
| 197 | return "" ; |
| 198 | } |
| 199 | return cast<GlobalObject>(Val: this)->getSection(); |
| 200 | } |
| 201 | |
| 202 | const Comdat *GlobalValue::getComdat() const { |
| 203 | if (auto *GA = dyn_cast<GlobalAlias>(Val: this)) { |
| 204 | // In general we cannot compute this at the IR level, but we try. |
| 205 | if (const GlobalObject *GO = GA->getAliaseeObject()) |
| 206 | return const_cast<GlobalObject *>(GO)->getComdat(); |
| 207 | return nullptr; |
| 208 | } |
| 209 | // ifunc and its resolver are separate things so don't use resolver comdat. |
| 210 | if (isa<GlobalIFunc>(Val: this)) |
| 211 | return nullptr; |
| 212 | return cast<GlobalObject>(Val: this)->getComdat(); |
| 213 | } |
| 214 | |
| 215 | void GlobalObject::setComdat(Comdat *C) { |
| 216 | if (ObjComdat) |
| 217 | ObjComdat->removeUser(GO: this); |
| 218 | ObjComdat = C; |
| 219 | if (C) |
| 220 | C->addUser(GO: this); |
| 221 | } |
| 222 | |
| 223 | StringRef GlobalValue::getPartition() const { |
| 224 | if (!hasPartition()) |
| 225 | return "" ; |
| 226 | return getContext().pImpl->GlobalValuePartitions[this]; |
| 227 | } |
| 228 | |
| 229 | void GlobalValue::setPartition(StringRef S) { |
| 230 | // Do nothing if we're clearing the partition and it is already empty. |
| 231 | if (!hasPartition() && S.empty()) |
| 232 | return; |
| 233 | |
| 234 | // Get or create a stable partition name string and put it in the table in the |
| 235 | // context. |
| 236 | if (!S.empty()) |
| 237 | S = getContext().pImpl->Saver.save(S); |
| 238 | getContext().pImpl->GlobalValuePartitions[this] = S; |
| 239 | |
| 240 | // Update the HasPartition field. Setting the partition to the empty string |
| 241 | // means this global no longer has a partition. |
| 242 | HasPartition = !S.empty(); |
| 243 | } |
| 244 | |
| 245 | using SanitizerMetadata = GlobalValue::SanitizerMetadata; |
| 246 | const SanitizerMetadata &GlobalValue::getSanitizerMetadata() const { |
| 247 | assert(hasSanitizerMetadata()); |
| 248 | assert(getContext().pImpl->GlobalValueSanitizerMetadata.count(this)); |
| 249 | return getContext().pImpl->GlobalValueSanitizerMetadata[this]; |
| 250 | } |
| 251 | |
| 252 | void GlobalValue::setSanitizerMetadata(SanitizerMetadata Meta) { |
| 253 | getContext().pImpl->GlobalValueSanitizerMetadata[this] = Meta; |
| 254 | HasSanitizerMetadata = true; |
| 255 | } |
| 256 | |
| 257 | void GlobalValue::removeSanitizerMetadata() { |
| 258 | DenseMap<const GlobalValue *, SanitizerMetadata> &MetadataMap = |
| 259 | getContext().pImpl->GlobalValueSanitizerMetadata; |
| 260 | MetadataMap.erase(Val: this); |
| 261 | HasSanitizerMetadata = false; |
| 262 | } |
| 263 | |
| 264 | void GlobalValue::setNoSanitizeMetadata() { |
| 265 | SanitizerMetadata Meta; |
| 266 | Meta.NoAddress = true; |
| 267 | Meta.NoHWAddress = true; |
| 268 | setSanitizerMetadata(Meta); |
| 269 | } |
| 270 | |
| 271 | StringRef GlobalObject::getSectionImpl() const { |
| 272 | assert(hasSection()); |
| 273 | return getContext().pImpl->GlobalObjectSections[this]; |
| 274 | } |
| 275 | |
| 276 | void GlobalObject::setSection(StringRef S) { |
| 277 | // Do nothing if we're clearing the section and it is already empty. |
| 278 | if (!hasSection() && S.empty()) |
| 279 | return; |
| 280 | |
| 281 | // Get or create a stable section name string and put it in the table in the |
| 282 | // context. |
| 283 | if (!S.empty()) |
| 284 | S = getContext().pImpl->Saver.save(S); |
| 285 | getContext().pImpl->GlobalObjectSections[this] = S; |
| 286 | |
| 287 | // Update the HasSectionHashEntryBit. Setting the section to the empty string |
| 288 | // means this global no longer has a section. |
| 289 | setGlobalObjectFlag(Bit: HasSectionHashEntryBit, Val: !S.empty()); |
| 290 | } |
| 291 | |
| 292 | bool GlobalObject::setSectionPrefix(StringRef Prefix) { |
| 293 | StringRef ExistingPrefix; |
| 294 | if (std::optional<StringRef> MaybePrefix = getSectionPrefix()) |
| 295 | ExistingPrefix = *MaybePrefix; |
| 296 | |
| 297 | if (ExistingPrefix == Prefix) |
| 298 | return false; |
| 299 | |
| 300 | if (Prefix.empty()) { |
| 301 | setMetadata(KindID: LLVMContext::MD_section_prefix, Node: nullptr); |
| 302 | return true; |
| 303 | } |
| 304 | MDBuilder MDB(getContext()); |
| 305 | setMetadata(KindID: LLVMContext::MD_section_prefix, |
| 306 | Node: MDB.createGlobalObjectSectionPrefix(Prefix)); |
| 307 | return true; |
| 308 | } |
| 309 | |
| 310 | std::optional<StringRef> GlobalObject::getSectionPrefix() const { |
| 311 | if (MDNode *MD = getMetadata(KindID: LLVMContext::MD_section_prefix)) { |
| 312 | [[maybe_unused]] StringRef MDName = |
| 313 | cast<MDString>(Val: MD->getOperand(I: 0))->getString(); |
| 314 | assert((MDName == "section_prefix" || |
| 315 | (isa<Function>(this) && MDName == "function_section_prefix" )) && |
| 316 | "Metadata not match" ); |
| 317 | return cast<MDString>(Val: MD->getOperand(I: 1))->getString(); |
| 318 | } |
| 319 | return std::nullopt; |
| 320 | } |
| 321 | |
| 322 | bool GlobalValue::isNobuiltinFnDef() const { |
| 323 | const Function *F = dyn_cast<Function>(Val: this); |
| 324 | if (!F || F->empty()) |
| 325 | return false; |
| 326 | return F->hasFnAttribute(Kind: Attribute::NoBuiltin); |
| 327 | } |
| 328 | |
| 329 | bool GlobalValue::isDeclaration() const { |
| 330 | // Globals are definitions if they have an initializer. |
| 331 | if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Val: this)) |
| 332 | return GV->getNumOperands() == 0; |
| 333 | |
| 334 | // Functions are definitions if they have a body. |
| 335 | if (const Function *F = dyn_cast<Function>(Val: this)) |
| 336 | return F->empty() && !F->isMaterializable(); |
| 337 | |
| 338 | // Aliases and ifuncs are always definitions. |
| 339 | assert(isa<GlobalAlias>(this) || isa<GlobalIFunc>(this)); |
| 340 | return false; |
| 341 | } |
| 342 | |
| 343 | bool GlobalObject::canIncreaseAlignment() const { |
| 344 | // Firstly, can only increase the alignment of a global if it |
| 345 | // is a strong definition. |
| 346 | if (!isStrongDefinitionForLinker()) |
| 347 | return false; |
| 348 | |
| 349 | // It also has to either not have a section defined, or, not have |
| 350 | // alignment specified. (If it is assigned a section, the global |
| 351 | // could be densely packed with other objects in the section, and |
| 352 | // increasing the alignment could cause padding issues.) |
| 353 | if (hasSection() && getAlign()) |
| 354 | return false; |
| 355 | |
| 356 | // On ELF platforms, we're further restricted in that we can't |
| 357 | // increase the alignment of any variable which might be emitted |
| 358 | // into a shared library, and which is exported. If the main |
| 359 | // executable accesses a variable found in a shared-lib, the main |
| 360 | // exe actually allocates memory for and exports the symbol ITSELF, |
| 361 | // overriding the symbol found in the library. That is, at link |
| 362 | // time, the observed alignment of the variable is copied into the |
| 363 | // executable binary. (A COPY relocation is also generated, to copy |
| 364 | // the initial data from the shadowed variable in the shared-lib |
| 365 | // into the location in the main binary, before running code.) |
| 366 | // |
| 367 | // And thus, even though you might think you are defining the |
| 368 | // global, and allocating the memory for the global in your object |
| 369 | // file, and thus should be able to set the alignment arbitrarily, |
| 370 | // that's not actually true. Doing so can cause an ABI breakage; an |
| 371 | // executable might have already been built with the previous |
| 372 | // alignment of the variable, and then assuming an increased |
| 373 | // alignment will be incorrect. |
| 374 | |
| 375 | // Conservatively assume ELF if there's no parent pointer. |
| 376 | bool isELF = (!Parent || Parent->getTargetTriple().isOSBinFormatELF()); |
| 377 | if (isELF && !isDSOLocal()) |
| 378 | return false; |
| 379 | |
| 380 | // GV with toc-data attribute is defined in a TOC entry. To mitigate TOC |
| 381 | // overflow, the alignment of such symbol should not be increased. Otherwise, |
| 382 | // padding is needed thus more TOC entries are wasted. |
| 383 | bool isXCOFF = (!Parent || Parent->getTargetTriple().isOSBinFormatXCOFF()); |
| 384 | if (isXCOFF) |
| 385 | if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(Val: this)) |
| 386 | if (GV->hasAttribute(Kind: "toc-data" )) |
| 387 | return false; |
| 388 | |
| 389 | return true; |
| 390 | } |
| 391 | |
| 392 | bool GlobalObject::hasMetadataOtherThanDebugLoc() const { |
| 393 | SmallVector<std::pair<unsigned, MDNode *>, 4> MDs; |
| 394 | getAllMetadata(MDs); |
| 395 | for (const auto &V : MDs) |
| 396 | if (V.first != LLVMContext::MD_dbg) |
| 397 | return true; |
| 398 | return false; |
| 399 | } |
| 400 | |
| 401 | template <typename Operation> |
| 402 | static const GlobalObject * |
| 403 | findBaseObject(const Constant *C, DenseSet<const GlobalAlias *> &Aliases, |
| 404 | const Operation &Op) { |
| 405 | if (auto *GO = dyn_cast<GlobalObject>(Val: C)) { |
| 406 | Op(*GO); |
| 407 | return GO; |
| 408 | } |
| 409 | if (auto *GA = dyn_cast<GlobalAlias>(Val: C)) { |
| 410 | Op(*GA); |
| 411 | if (Aliases.insert(V: GA).second) |
| 412 | return findBaseObject(GA->getOperand(i_nocapture: 0), Aliases, Op); |
| 413 | } |
| 414 | if (auto *CE = dyn_cast<ConstantExpr>(Val: C)) { |
| 415 | switch (CE->getOpcode()) { |
| 416 | case Instruction::Add: { |
| 417 | auto *LHS = findBaseObject(CE->getOperand(i_nocapture: 0), Aliases, Op); |
| 418 | auto *RHS = findBaseObject(CE->getOperand(i_nocapture: 1), Aliases, Op); |
| 419 | if (LHS && RHS) |
| 420 | return nullptr; |
| 421 | return LHS ? LHS : RHS; |
| 422 | } |
| 423 | case Instruction::Sub: { |
| 424 | if (findBaseObject(CE->getOperand(i_nocapture: 1), Aliases, Op)) |
| 425 | return nullptr; |
| 426 | return findBaseObject(CE->getOperand(i_nocapture: 0), Aliases, Op); |
| 427 | } |
| 428 | case Instruction::IntToPtr: |
| 429 | case Instruction::PtrToAddr: |
| 430 | case Instruction::PtrToInt: |
| 431 | case Instruction::BitCast: |
| 432 | case Instruction::AddrSpaceCast: |
| 433 | case Instruction::GetElementPtr: |
| 434 | return findBaseObject(CE->getOperand(i_nocapture: 0), Aliases, Op); |
| 435 | default: |
| 436 | break; |
| 437 | } |
| 438 | } |
| 439 | return nullptr; |
| 440 | } |
| 441 | |
| 442 | const GlobalObject *GlobalValue::getAliaseeObject() const { |
| 443 | DenseSet<const GlobalAlias *> Aliases; |
| 444 | return findBaseObject(C: this, Aliases, Op: [](const GlobalValue &) {}); |
| 445 | } |
| 446 | |
| 447 | bool GlobalValue::isAbsoluteSymbolRef() const { |
| 448 | auto *GO = dyn_cast<GlobalObject>(Val: this); |
| 449 | if (!GO) |
| 450 | return false; |
| 451 | |
| 452 | return GO->getMetadata(KindID: LLVMContext::MD_absolute_symbol); |
| 453 | } |
| 454 | |
| 455 | std::optional<ConstantRange> GlobalValue::getAbsoluteSymbolRange() const { |
| 456 | auto *GO = dyn_cast<GlobalObject>(Val: this); |
| 457 | if (!GO) |
| 458 | return std::nullopt; |
| 459 | |
| 460 | MDNode *MD = GO->getMetadata(KindID: LLVMContext::MD_absolute_symbol); |
| 461 | if (!MD) |
| 462 | return std::nullopt; |
| 463 | |
| 464 | return getConstantRangeFromMetadata(RangeMD: *MD); |
| 465 | } |
| 466 | |
| 467 | bool GlobalValue::canBeOmittedFromSymbolTable() const { |
| 468 | if (!hasLinkOnceODRLinkage()) |
| 469 | return false; |
| 470 | |
| 471 | // We assume that anyone who sets global unnamed_addr on a non-constant |
| 472 | // knows what they're doing. |
| 473 | if (hasGlobalUnnamedAddr()) |
| 474 | return true; |
| 475 | |
| 476 | // If it is a non constant variable, it needs to be uniqued across shared |
| 477 | // objects. |
| 478 | if (auto *Var = dyn_cast<GlobalVariable>(Val: this)) |
| 479 | if (!Var->isConstant()) |
| 480 | return false; |
| 481 | |
| 482 | return hasAtLeastLocalUnnamedAddr(); |
| 483 | } |
| 484 | |
| 485 | //===----------------------------------------------------------------------===// |
| 486 | // GlobalVariable Implementation |
| 487 | //===----------------------------------------------------------------------===// |
| 488 | |
| 489 | GlobalVariable::GlobalVariable(Type *Ty, bool constant, LinkageTypes Link, |
| 490 | Constant *InitVal, const Twine &Name, |
| 491 | ThreadLocalMode TLMode, unsigned AddressSpace, |
| 492 | bool isExternallyInitialized) |
| 493 | : GlobalObject(Ty, Value::GlobalVariableVal, AllocMarker, Link, Name, |
| 494 | AddressSpace), |
| 495 | isConstantGlobal(constant), |
| 496 | isExternallyInitializedConstant(isExternallyInitialized) { |
| 497 | assert(!Ty->isFunctionTy() && PointerType::isValidElementType(Ty) && |
| 498 | "invalid type for global variable" ); |
| 499 | setThreadLocalMode(TLMode); |
| 500 | if (InitVal) { |
| 501 | assert(InitVal->getType() == Ty && |
| 502 | "Initializer should be the same type as the GlobalVariable!" ); |
| 503 | Op<0>() = InitVal; |
| 504 | } else { |
| 505 | setGlobalVariableNumOperands(0); |
| 506 | } |
| 507 | } |
| 508 | |
| 509 | GlobalVariable::GlobalVariable(Module &M, Type *Ty, bool constant, |
| 510 | LinkageTypes Link, Constant *InitVal, |
| 511 | const Twine &Name, GlobalVariable *Before, |
| 512 | ThreadLocalMode TLMode, |
| 513 | std::optional<unsigned> AddressSpace, |
| 514 | bool isExternallyInitialized) |
| 515 | : GlobalVariable(Ty, constant, Link, InitVal, Name, TLMode, |
| 516 | AddressSpace |
| 517 | ? *AddressSpace |
| 518 | : M.getDataLayout().getDefaultGlobalsAddressSpace(), |
| 519 | isExternallyInitialized) { |
| 520 | if (Before) |
| 521 | Before->getParent()->insertGlobalVariable(Where: Before->getIterator(), GV: this); |
| 522 | else |
| 523 | M.insertGlobalVariable(GV: this); |
| 524 | } |
| 525 | |
| 526 | void GlobalVariable::removeFromParent() { |
| 527 | getParent()->removeGlobalVariable(GV: this); |
| 528 | } |
| 529 | |
| 530 | void GlobalVariable::eraseFromParent() { |
| 531 | getParent()->eraseGlobalVariable(GV: this); |
| 532 | } |
| 533 | |
| 534 | void GlobalVariable::setInitializer(Constant *InitVal) { |
| 535 | if (!InitVal) { |
| 536 | if (hasInitializer()) { |
| 537 | // Note, the num operands is used to compute the offset of the operand, so |
| 538 | // the order here matters. Clearing the operand then clearing the num |
| 539 | // operands ensures we have the correct offset to the operand. |
| 540 | Op<0>().set(nullptr); |
| 541 | setGlobalVariableNumOperands(0); |
| 542 | } |
| 543 | } else { |
| 544 | assert(InitVal->getType() == getValueType() && |
| 545 | "Initializer type must match GlobalVariable type" ); |
| 546 | // Note, the num operands is used to compute the offset of the operand, so |
| 547 | // the order here matters. We need to set num operands to 1 first so that |
| 548 | // we get the correct offset to the first operand when we set it. |
| 549 | if (!hasInitializer()) |
| 550 | setGlobalVariableNumOperands(1); |
| 551 | Op<0>().set(InitVal); |
| 552 | } |
| 553 | } |
| 554 | |
| 555 | void GlobalVariable::replaceInitializer(Constant *InitVal) { |
| 556 | assert(InitVal && "Can't compute type of null initializer" ); |
| 557 | ValueType = InitVal->getType(); |
| 558 | setInitializer(InitVal); |
| 559 | } |
| 560 | |
| 561 | uint64_t GlobalVariable::getGlobalSize(const DataLayout &DL) const { |
| 562 | // We don't support scalable global variables. |
| 563 | return DL.getTypeAllocSize(Ty: getValueType()).getFixedValue(); |
| 564 | } |
| 565 | |
| 566 | /// Copy all additional attributes (those not needed to create a GlobalVariable) |
| 567 | /// from the GlobalVariable Src to this one. |
| 568 | void GlobalVariable::copyAttributesFrom(const GlobalVariable *Src) { |
| 569 | GlobalObject::copyAttributesFrom(Src); |
| 570 | setExternallyInitialized(Src->isExternallyInitialized()); |
| 571 | setAttributes(Src->getAttributes()); |
| 572 | if (auto CM = Src->getCodeModel()) |
| 573 | setCodeModel(*CM); |
| 574 | } |
| 575 | |
| 576 | void GlobalVariable::dropAllReferences() { |
| 577 | User::dropAllReferences(); |
| 578 | clearMetadata(); |
| 579 | } |
| 580 | |
| 581 | void GlobalVariable::setCodeModel(CodeModel::Model CM) { |
| 582 | unsigned CodeModelData = static_cast<unsigned>(CM) + 1; |
| 583 | unsigned OldData = getGlobalValueSubClassData(); |
| 584 | unsigned NewData = (OldData & ~(CodeModelMask << CodeModelShift)) | |
| 585 | (CodeModelData << CodeModelShift); |
| 586 | setGlobalValueSubClassData(NewData); |
| 587 | assert(getCodeModel() == CM && "Code model representation error!" ); |
| 588 | } |
| 589 | |
| 590 | void GlobalVariable::clearCodeModel() { |
| 591 | unsigned CodeModelData = 0; |
| 592 | unsigned OldData = getGlobalValueSubClassData(); |
| 593 | unsigned NewData = (OldData & ~(CodeModelMask << CodeModelShift)) | |
| 594 | (CodeModelData << CodeModelShift); |
| 595 | setGlobalValueSubClassData(NewData); |
| 596 | assert(getCodeModel() == std::nullopt && "Code model representation error!" ); |
| 597 | } |
| 598 | |
| 599 | //===----------------------------------------------------------------------===// |
| 600 | // GlobalAlias Implementation |
| 601 | //===----------------------------------------------------------------------===// |
| 602 | |
| 603 | GlobalAlias::GlobalAlias(Type *Ty, unsigned AddressSpace, LinkageTypes Link, |
| 604 | const Twine &Name, Constant *Aliasee, |
| 605 | Module *ParentModule) |
| 606 | : GlobalValue(Ty, Value::GlobalAliasVal, AllocMarker, Link, Name, |
| 607 | AddressSpace) { |
| 608 | setAliasee(Aliasee); |
| 609 | if (ParentModule) |
| 610 | ParentModule->insertAlias(Alias: this); |
| 611 | } |
| 612 | |
| 613 | GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace, |
| 614 | LinkageTypes Link, const Twine &Name, |
| 615 | Constant *Aliasee, Module *ParentModule) { |
| 616 | return new GlobalAlias(Ty, AddressSpace, Link, Name, Aliasee, ParentModule); |
| 617 | } |
| 618 | |
| 619 | GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace, |
| 620 | LinkageTypes Linkage, const Twine &Name, |
| 621 | Module *Parent) { |
| 622 | return create(Ty, AddressSpace, Link: Linkage, Name, Aliasee: nullptr, ParentModule: Parent); |
| 623 | } |
| 624 | |
| 625 | GlobalAlias *GlobalAlias::create(Type *Ty, unsigned AddressSpace, |
| 626 | LinkageTypes Linkage, const Twine &Name, |
| 627 | GlobalValue *Aliasee) { |
| 628 | return create(Ty, AddressSpace, Link: Linkage, Name, Aliasee, ParentModule: Aliasee->getParent()); |
| 629 | } |
| 630 | |
| 631 | GlobalAlias *GlobalAlias::create(LinkageTypes Link, const Twine &Name, |
| 632 | GlobalValue *Aliasee) { |
| 633 | return create(Ty: Aliasee->getValueType(), AddressSpace: Aliasee->getAddressSpace(), Linkage: Link, Name, |
| 634 | Aliasee); |
| 635 | } |
| 636 | |
| 637 | GlobalAlias *GlobalAlias::create(const Twine &Name, GlobalValue *Aliasee) { |
| 638 | return create(Link: Aliasee->getLinkage(), Name, Aliasee); |
| 639 | } |
| 640 | |
| 641 | void GlobalAlias::removeFromParent() { getParent()->removeAlias(Alias: this); } |
| 642 | |
| 643 | void GlobalAlias::eraseFromParent() { getParent()->eraseAlias(Alias: this); } |
| 644 | |
| 645 | void GlobalAlias::setAliasee(Constant *Aliasee) { |
| 646 | assert((!Aliasee || Aliasee->getType() == getType()) && |
| 647 | "Alias and aliasee types should match!" ); |
| 648 | Op<0>().set(Aliasee); |
| 649 | } |
| 650 | |
| 651 | const GlobalObject *GlobalAlias::getAliaseeObject() const { |
| 652 | DenseSet<const GlobalAlias *> Aliases; |
| 653 | return findBaseObject(C: getOperand(i_nocapture: 0), Aliases, Op: [](const GlobalValue &) {}); |
| 654 | } |
| 655 | |
| 656 | //===----------------------------------------------------------------------===// |
| 657 | // GlobalIFunc Implementation |
| 658 | //===----------------------------------------------------------------------===// |
| 659 | |
| 660 | GlobalIFunc::GlobalIFunc(Type *Ty, unsigned AddressSpace, LinkageTypes Link, |
| 661 | const Twine &Name, Constant *Resolver, |
| 662 | Module *ParentModule) |
| 663 | : GlobalObject(Ty, Value::GlobalIFuncVal, AllocMarker, Link, Name, |
| 664 | AddressSpace) { |
| 665 | setResolver(Resolver); |
| 666 | if (ParentModule) |
| 667 | ParentModule->insertIFunc(IFunc: this); |
| 668 | } |
| 669 | |
| 670 | GlobalIFunc *GlobalIFunc::create(Type *Ty, unsigned AddressSpace, |
| 671 | LinkageTypes Link, const Twine &Name, |
| 672 | Constant *Resolver, Module *ParentModule) { |
| 673 | return new GlobalIFunc(Ty, AddressSpace, Link, Name, Resolver, ParentModule); |
| 674 | } |
| 675 | |
| 676 | void GlobalIFunc::removeFromParent() { getParent()->removeIFunc(IFunc: this); } |
| 677 | |
| 678 | void GlobalIFunc::eraseFromParent() { getParent()->eraseIFunc(IFunc: this); } |
| 679 | |
| 680 | const Function *GlobalIFunc::getResolverFunction() const { |
| 681 | return dyn_cast<Function>(Val: getResolver()->stripPointerCastsAndAliases()); |
| 682 | } |
| 683 | |
| 684 | void GlobalIFunc::applyAlongResolverPath( |
| 685 | function_ref<void(const GlobalValue &)> Op) const { |
| 686 | DenseSet<const GlobalAlias *> Aliases; |
| 687 | findBaseObject(C: getResolver(), Aliases, Op); |
| 688 | } |
| 689 | |