1 //===-- Module.cpp - Implement the Module class ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Module class for the IR library.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/IR/Module.h"
15 #include "SymbolTableListTraitsImpl.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallPtrSet.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/IR/Constants.h"
21 #include "llvm/IR/DerivedTypes.h"
22 #include "llvm/IR/DebugInfoMetadata.h"
23 #include "llvm/IR/GVMaterializer.h"
24 #include "llvm/IR/InstrTypes.h"
25 #include "llvm/IR/LLVMContext.h"
26 #include "llvm/IR/TypeFinder.h"
27 #include "llvm/Support/Dwarf.h"
28 #include "llvm/Support/Path.h"
29 #include "llvm/Support/RandomNumberGenerator.h"
36 //===----------------------------------------------------------------------===//
37 // Methods to implement the globals and functions lists.
40 // Explicit instantiations of SymbolTableListTraits since some of the methods
41 // are not in the public header file.
42 template class llvm::SymbolTableListTraits<Function>;
43 template class llvm::SymbolTableListTraits<GlobalVariable>;
44 template class llvm::SymbolTableListTraits<GlobalAlias>;
45 template class llvm::SymbolTableListTraits<GlobalIFunc>;
47 //===----------------------------------------------------------------------===//
48 // Primitive Module methods.
51 Module::Module(StringRef MID, LLVMContext &C)
52 : Context(C), Materializer(), ModuleID(MID), SourceFileName(MID), DL("") {
53 ValSymTab = new ValueSymbolTable();
54 NamedMDSymTab = new StringMap<NamedMDNode *>();
55 Context.addModule(this);
59 Context.removeModule(this);
67 delete static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab);
70 RandomNumberGenerator *Module::createRNG(const Pass* P) const {
71 SmallString<32> Salt(P->getPassName());
73 // This RNG is guaranteed to produce the same random stream only
74 // when the Module ID and thus the input filename is the same. This
75 // might be problematic if the input filename extension changes
76 // (e.g. from .c to .bc or .ll).
78 // We could store this salt in NamedMetadata, but this would make
79 // the parameter non-const. This would unfortunately make this
80 // interface unusable by any Machine passes, since they only have a
81 // const reference to their IR Module. Alternatively we can always
82 // store salt metadata from the Module constructor.
83 Salt += sys::path::filename(getModuleIdentifier());
85 return new RandomNumberGenerator(Salt);
88 /// getNamedValue - Return the first global value in the module with
89 /// the specified name, of arbitrary type. This method returns null
90 /// if a global with the specified name is not found.
91 GlobalValue *Module::getNamedValue(StringRef Name) const {
92 return cast_or_null<GlobalValue>(getValueSymbolTable().lookup(Name));
95 /// getMDKindID - Return a unique non-zero ID for the specified metadata kind.
96 /// This ID is uniqued across modules in the current LLVMContext.
97 unsigned Module::getMDKindID(StringRef Name) const {
98 return Context.getMDKindID(Name);
101 /// getMDKindNames - Populate client supplied SmallVector with the name for
102 /// custom metadata IDs registered in this LLVMContext. ID #0 is not used,
103 /// so it is filled in as an empty string.
104 void Module::getMDKindNames(SmallVectorImpl<StringRef> &Result) const {
105 return Context.getMDKindNames(Result);
108 void Module::getOperandBundleTags(SmallVectorImpl<StringRef> &Result) const {
109 return Context.getOperandBundleTags(Result);
112 //===----------------------------------------------------------------------===//
113 // Methods for easy access to the functions in the module.
116 // getOrInsertFunction - Look up the specified function in the module symbol
117 // table. If it does not exist, add a prototype for the function and return
118 // it. This is nice because it allows most passes to get away with not handling
119 // the symbol table directly for this common task.
121 Constant *Module::getOrInsertFunction(StringRef Name,
123 AttributeSet AttributeList) {
124 // See if we have a definition for the specified function already.
125 GlobalValue *F = getNamedValue(Name);
128 Function *New = Function::Create(Ty, GlobalVariable::ExternalLinkage, Name);
129 if (!New->isIntrinsic()) // Intrinsics get attrs set on construction
130 New->setAttributes(AttributeList);
131 FunctionList.push_back(New);
132 return New; // Return the new prototype.
135 // If the function exists but has the wrong type, return a bitcast to the
137 if (F->getType() != PointerType::getUnqual(Ty))
138 return ConstantExpr::getBitCast(F, PointerType::getUnqual(Ty));
140 // Otherwise, we just found the existing function or a prototype.
144 Constant *Module::getOrInsertFunction(StringRef Name,
146 return getOrInsertFunction(Name, Ty, AttributeSet());
149 // getOrInsertFunction - Look up the specified function in the module symbol
150 // table. If it does not exist, add a prototype for the function and return it.
151 // This version of the method takes a null terminated list of function
152 // arguments, which makes it easier for clients to use.
154 Constant *Module::getOrInsertFunction(StringRef Name,
155 AttributeSet AttributeList,
158 va_start(Args, RetTy);
160 // Build the list of argument types...
161 std::vector<Type*> ArgTys;
162 while (Type *ArgTy = va_arg(Args, Type*))
163 ArgTys.push_back(ArgTy);
167 // Build the function type and chain to the other getOrInsertFunction...
168 return getOrInsertFunction(Name,
169 FunctionType::get(RetTy, ArgTys, false),
173 Constant *Module::getOrInsertFunction(StringRef Name,
176 va_start(Args, RetTy);
178 // Build the list of argument types...
179 std::vector<Type*> ArgTys;
180 while (Type *ArgTy = va_arg(Args, Type*))
181 ArgTys.push_back(ArgTy);
185 // Build the function type and chain to the other getOrInsertFunction...
186 return getOrInsertFunction(Name,
187 FunctionType::get(RetTy, ArgTys, false),
191 // getFunction - Look up the specified function in the module symbol table.
192 // If it does not exist, return null.
194 Function *Module::getFunction(StringRef Name) const {
195 return dyn_cast_or_null<Function>(getNamedValue(Name));
198 //===----------------------------------------------------------------------===//
199 // Methods for easy access to the global variables in the module.
202 /// getGlobalVariable - Look up the specified global variable in the module
203 /// symbol table. If it does not exist, return null. The type argument
204 /// should be the underlying type of the global, i.e., it should not have
205 /// the top-level PointerType, which represents the address of the global.
206 /// If AllowLocal is set to true, this function will return types that
207 /// have an local. By default, these types are not returned.
209 GlobalVariable *Module::getGlobalVariable(StringRef Name, bool AllowLocal) {
210 if (GlobalVariable *Result =
211 dyn_cast_or_null<GlobalVariable>(getNamedValue(Name)))
212 if (AllowLocal || !Result->hasLocalLinkage())
217 /// getOrInsertGlobal - Look up the specified global in the module symbol table.
218 /// 1. If it does not exist, add a declaration of the global and return it.
219 /// 2. Else, the global exists but has the wrong type: return the function
220 /// with a constantexpr cast to the right type.
221 /// 3. Finally, if the existing global is the correct declaration, return the
223 Constant *Module::getOrInsertGlobal(StringRef Name, Type *Ty) {
224 // See if we have a definition for the specified global already.
225 GlobalVariable *GV = dyn_cast_or_null<GlobalVariable>(getNamedValue(Name));
228 GlobalVariable *New =
229 new GlobalVariable(*this, Ty, false, GlobalVariable::ExternalLinkage,
231 return New; // Return the new declaration.
234 // If the variable exists but has the wrong type, return a bitcast to the
236 Type *GVTy = GV->getType();
237 PointerType *PTy = PointerType::get(Ty, GVTy->getPointerAddressSpace());
239 return ConstantExpr::getBitCast(GV, PTy);
241 // Otherwise, we just found the existing function or a prototype.
245 //===----------------------------------------------------------------------===//
246 // Methods for easy access to the global variables in the module.
249 // getNamedAlias - Look up the specified global in the module symbol table.
250 // If it does not exist, return null.
252 GlobalAlias *Module::getNamedAlias(StringRef Name) const {
253 return dyn_cast_or_null<GlobalAlias>(getNamedValue(Name));
256 GlobalIFunc *Module::getNamedIFunc(StringRef Name) const {
257 return dyn_cast_or_null<GlobalIFunc>(getNamedValue(Name));
260 /// getNamedMetadata - Return the first NamedMDNode in the module with the
261 /// specified name. This method returns null if a NamedMDNode with the
262 /// specified name is not found.
263 NamedMDNode *Module::getNamedMetadata(const Twine &Name) const {
264 SmallString<256> NameData;
265 StringRef NameRef = Name.toStringRef(NameData);
266 return static_cast<StringMap<NamedMDNode*> *>(NamedMDSymTab)->lookup(NameRef);
269 /// getOrInsertNamedMetadata - Return the first named MDNode in the module
270 /// with the specified name. This method returns a new NamedMDNode if a
271 /// NamedMDNode with the specified name is not found.
272 NamedMDNode *Module::getOrInsertNamedMetadata(StringRef Name) {
274 (*static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab))[Name];
276 NMD = new NamedMDNode(Name);
277 NMD->setParent(this);
278 NamedMDList.push_back(NMD);
283 /// eraseNamedMetadata - Remove the given NamedMDNode from this module and
285 void Module::eraseNamedMetadata(NamedMDNode *NMD) {
286 static_cast<StringMap<NamedMDNode *> *>(NamedMDSymTab)->erase(NMD->getName());
287 NamedMDList.erase(NMD->getIterator());
290 bool Module::isValidModFlagBehavior(Metadata *MD, ModFlagBehavior &MFB) {
291 if (ConstantInt *Behavior = mdconst::dyn_extract_or_null<ConstantInt>(MD)) {
292 uint64_t Val = Behavior->getLimitedValue();
293 if (Val >= ModFlagBehaviorFirstVal && Val <= ModFlagBehaviorLastVal) {
294 MFB = static_cast<ModFlagBehavior>(Val);
301 /// getModuleFlagsMetadata - Returns the module flags in the provided vector.
303 getModuleFlagsMetadata(SmallVectorImpl<ModuleFlagEntry> &Flags) const {
304 const NamedMDNode *ModFlags = getModuleFlagsMetadata();
305 if (!ModFlags) return;
307 for (const MDNode *Flag : ModFlags->operands()) {
309 if (Flag->getNumOperands() >= 3 &&
310 isValidModFlagBehavior(Flag->getOperand(0), MFB) &&
311 dyn_cast_or_null<MDString>(Flag->getOperand(1))) {
312 // Check the operands of the MDNode before accessing the operands.
313 // The verifier will actually catch these failures.
314 MDString *Key = cast<MDString>(Flag->getOperand(1));
315 Metadata *Val = Flag->getOperand(2);
316 Flags.push_back(ModuleFlagEntry(MFB, Key, Val));
321 /// Return the corresponding value if Key appears in module flags, otherwise
323 Metadata *Module::getModuleFlag(StringRef Key) const {
324 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
325 getModuleFlagsMetadata(ModuleFlags);
326 for (const ModuleFlagEntry &MFE : ModuleFlags) {
327 if (Key == MFE.Key->getString())
333 /// getModuleFlagsMetadata - Returns the NamedMDNode in the module that
334 /// represents module-level flags. This method returns null if there are no
335 /// module-level flags.
336 NamedMDNode *Module::getModuleFlagsMetadata() const {
337 return getNamedMetadata("llvm.module.flags");
340 /// getOrInsertModuleFlagsMetadata - Returns the NamedMDNode in the module that
341 /// represents module-level flags. If module-level flags aren't found, it
342 /// creates the named metadata that contains them.
343 NamedMDNode *Module::getOrInsertModuleFlagsMetadata() {
344 return getOrInsertNamedMetadata("llvm.module.flags");
347 /// addModuleFlag - Add a module-level flag to the module-level flags
348 /// metadata. It will create the module-level flags named metadata if it doesn't
350 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
352 Type *Int32Ty = Type::getInt32Ty(Context);
354 ConstantAsMetadata::get(ConstantInt::get(Int32Ty, Behavior)),
355 MDString::get(Context, Key), Val};
356 getOrInsertModuleFlagsMetadata()->addOperand(MDNode::get(Context, Ops));
358 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
360 addModuleFlag(Behavior, Key, ConstantAsMetadata::get(Val));
362 void Module::addModuleFlag(ModFlagBehavior Behavior, StringRef Key,
364 Type *Int32Ty = Type::getInt32Ty(Context);
365 addModuleFlag(Behavior, Key, ConstantInt::get(Int32Ty, Val));
367 void Module::addModuleFlag(MDNode *Node) {
368 assert(Node->getNumOperands() == 3 &&
369 "Invalid number of operands for module flag!");
370 assert(mdconst::hasa<ConstantInt>(Node->getOperand(0)) &&
371 isa<MDString>(Node->getOperand(1)) &&
372 "Invalid operand types for module flag!");
373 getOrInsertModuleFlagsMetadata()->addOperand(Node);
376 void Module::setDataLayout(StringRef Desc) {
380 void Module::setDataLayout(const DataLayout &Other) { DL = Other; }
382 const DataLayout &Module::getDataLayout() const { return DL; }
384 DICompileUnit *Module::debug_compile_units_iterator::operator*() const {
385 return cast<DICompileUnit>(CUs->getOperand(Idx));
387 DICompileUnit *Module::debug_compile_units_iterator::operator->() const {
388 return cast<DICompileUnit>(CUs->getOperand(Idx));
391 void Module::debug_compile_units_iterator::SkipNoDebugCUs() {
392 while (CUs && (Idx < CUs->getNumOperands()) &&
393 ((*this)->getEmissionKind() == DICompileUnit::NoDebug))
397 //===----------------------------------------------------------------------===//
398 // Methods to control the materialization of GlobalValues in the Module.
400 void Module::setMaterializer(GVMaterializer *GVM) {
401 assert(!Materializer &&
402 "Module already has a GVMaterializer. Call materializeAll"
403 " to clear it out before setting another one.");
404 Materializer.reset(GVM);
407 std::error_code Module::materialize(GlobalValue *GV) {
409 return std::error_code();
411 return Materializer->materialize(GV);
414 std::error_code Module::materializeAll() {
416 return std::error_code();
417 std::unique_ptr<GVMaterializer> M = std::move(Materializer);
418 return M->materializeModule();
421 std::error_code Module::materializeMetadata() {
423 return std::error_code();
424 return Materializer->materializeMetadata();
427 //===----------------------------------------------------------------------===//
428 // Other module related stuff.
431 std::vector<StructType *> Module::getIdentifiedStructTypes() const {
432 // If we have a materializer, it is possible that some unread function
433 // uses a type that is currently not visible to a TypeFinder, so ask
434 // the materializer which types it created.
436 return Materializer->getIdentifiedStructTypes();
438 std::vector<StructType *> Ret;
439 TypeFinder SrcStructTypes;
440 SrcStructTypes.run(*this, true);
441 Ret.assign(SrcStructTypes.begin(), SrcStructTypes.end());
445 // dropAllReferences() - This function causes all the subelements to "let go"
446 // of all references that they are maintaining. This allows one to 'delete' a
447 // whole module at a time, even though there may be circular references... first
448 // all references are dropped, and all use counts go to zero. Then everything
449 // is deleted for real. Note that no operations are valid on an object that
450 // has "dropped all references", except operator delete.
452 void Module::dropAllReferences() {
453 for (Function &F : *this)
454 F.dropAllReferences();
456 for (GlobalVariable &GV : globals())
457 GV.dropAllReferences();
459 for (GlobalAlias &GA : aliases())
460 GA.dropAllReferences();
462 for (GlobalIFunc &GIF : ifuncs())
463 GIF.dropAllReferences();
466 unsigned Module::getDwarfVersion() const {
467 auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("Dwarf Version"));
470 return cast<ConstantInt>(Val->getValue())->getZExtValue();
473 unsigned Module::getCodeViewFlag() const {
474 auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("CodeView"));
477 return cast<ConstantInt>(Val->getValue())->getZExtValue();
480 Comdat *Module::getOrInsertComdat(StringRef Name) {
481 auto &Entry = *ComdatSymTab.insert(std::make_pair(Name, Comdat())).first;
482 Entry.second.Name = &Entry;
483 return &Entry.second;
486 PICLevel::Level Module::getPICLevel() const {
487 auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIC Level"));
490 return PICLevel::NotPIC;
492 return static_cast<PICLevel::Level>(
493 cast<ConstantInt>(Val->getValue())->getZExtValue());
496 void Module::setPICLevel(PICLevel::Level PL) {
497 addModuleFlag(ModFlagBehavior::Error, "PIC Level", PL);
500 PIELevel::Level Module::getPIELevel() const {
501 auto *Val = cast_or_null<ConstantAsMetadata>(getModuleFlag("PIE Level"));
504 return PIELevel::Default;
506 return static_cast<PIELevel::Level>(
507 cast<ConstantInt>(Val->getValue())->getZExtValue());
510 void Module::setPIELevel(PIELevel::Level PL) {
511 addModuleFlag(ModFlagBehavior::Error, "PIE Level", PL);
514 void Module::setProfileSummary(Metadata *M) {
515 addModuleFlag(ModFlagBehavior::Error, "ProfileSummary", M);
518 Metadata *Module::getProfileSummary() {
519 return getModuleFlag("ProfileSummary");
522 GlobalVariable *llvm::collectUsedGlobalVariables(
523 const Module &M, SmallPtrSetImpl<GlobalValue *> &Set, bool CompilerUsed) {
524 const char *Name = CompilerUsed ? "llvm.compiler.used" : "llvm.used";
525 GlobalVariable *GV = M.getGlobalVariable(Name);
526 if (!GV || !GV->hasInitializer())
529 const ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
530 for (Value *Op : Init->operands()) {
531 GlobalValue *G = cast<GlobalValue>(Op->stripPointerCastsNoFollowAliases());