1 //===-- Function.cpp - Implement the Global object classes ----------------===//
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 Function class for the IR library.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/IR/Function.h"
15 #include "LLVMContextImpl.h"
16 #include "SymbolTableListTraitsImpl.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/CodeGen/ValueTypes.h"
21 #include "llvm/IR/DerivedTypes.h"
22 #include "llvm/IR/IntrinsicInst.h"
23 #include "llvm/IR/LLVMContext.h"
24 #include "llvm/IR/Module.h"
25 #include "llvm/Support/CallSite.h"
26 #include "llvm/Support/InstIterator.h"
27 #include "llvm/Support/LeakDetector.h"
28 #include "llvm/Support/ManagedStatic.h"
29 #include "llvm/Support/RWMutex.h"
30 #include "llvm/Support/StringPool.h"
31 #include "llvm/Support/Threading.h"
34 // Explicit instantiations of SymbolTableListTraits since some of the methods
35 // are not in the public header file...
36 template class llvm::SymbolTableListTraits<Argument, Function>;
37 template class llvm::SymbolTableListTraits<BasicBlock, Function>;
39 //===----------------------------------------------------------------------===//
40 // Argument Implementation
41 //===----------------------------------------------------------------------===//
43 void Argument::anchor() { }
45 Argument::Argument(Type *Ty, const Twine &Name, Function *Par)
46 : Value(Ty, Value::ArgumentVal) {
49 // Make sure that we get added to a function
50 LeakDetector::addGarbageObject(this);
53 Par->getArgumentList().push_back(this);
57 void Argument::setParent(Function *parent) {
59 LeakDetector::addGarbageObject(this);
62 LeakDetector::removeGarbageObject(this);
65 /// getArgNo - Return the index of this formal argument in its containing
66 /// function. For example in "void foo(int a, float b)" a is 0 and b is 1.
67 unsigned Argument::getArgNo() const {
68 const Function *F = getParent();
69 assert(F && "Argument is not in a function");
71 Function::const_arg_iterator AI = F->arg_begin();
73 for (; &*AI != this; ++AI)
79 /// hasByValAttr - Return true if this argument has the byval attribute on it
80 /// in its containing function.
81 bool Argument::hasByValAttr() const {
82 if (!getType()->isPointerTy()) return false;
83 return getParent()->getAttributes().
84 hasAttribute(getArgNo()+1, Attribute::ByVal);
87 unsigned Argument::getParamAlignment() const {
88 assert(getType()->isPointerTy() && "Only pointers have alignments");
89 return getParent()->getParamAlignment(getArgNo()+1);
93 /// hasNestAttr - Return true if this argument has the nest attribute on
94 /// it in its containing function.
95 bool Argument::hasNestAttr() const {
96 if (!getType()->isPointerTy()) return false;
97 return getParent()->getAttributes().
98 hasAttribute(getArgNo()+1, Attribute::Nest);
101 /// hasNoAliasAttr - Return true if this argument has the noalias attribute on
102 /// it in its containing function.
103 bool Argument::hasNoAliasAttr() const {
104 if (!getType()->isPointerTy()) return false;
105 return getParent()->getAttributes().
106 hasAttribute(getArgNo()+1, Attribute::NoAlias);
109 /// hasNoCaptureAttr - Return true if this argument has the nocapture attribute
110 /// on it in its containing function.
111 bool Argument::hasNoCaptureAttr() const {
112 if (!getType()->isPointerTy()) return false;
113 return getParent()->getAttributes().
114 hasAttribute(getArgNo()+1, Attribute::NoCapture);
117 /// hasSRetAttr - Return true if this argument has the sret attribute on
118 /// it in its containing function.
119 bool Argument::hasStructRetAttr() const {
120 if (!getType()->isPointerTy()) return false;
121 if (this != getParent()->arg_begin())
122 return false; // StructRet param must be first param
123 return getParent()->getAttributes().
124 hasAttribute(1, Attribute::StructRet);
127 /// hasReturnedAttr - Return true if this argument has the returned attribute on
128 /// it in its containing function.
129 bool Argument::hasReturnedAttr() const {
130 return getParent()->getAttributes().
131 hasAttribute(getArgNo()+1, Attribute::Returned);
134 /// Return true if this argument has the readonly or readnone attribute on it
135 /// in its containing function.
136 bool Argument::onlyReadsMemory() const {
137 return getParent()->getAttributes().
138 hasAttribute(getArgNo()+1, Attribute::ReadOnly) ||
139 getParent()->getAttributes().
140 hasAttribute(getArgNo()+1, Attribute::ReadNone);
143 /// addAttr - Add attributes to an argument.
144 void Argument::addAttr(AttributeSet AS) {
145 assert(AS.getNumSlots() <= 1 &&
146 "Trying to add more than one attribute set to an argument!");
147 AttrBuilder B(AS, AS.getSlotIndex(0));
148 getParent()->addAttributes(getArgNo() + 1,
149 AttributeSet::get(Parent->getContext(),
153 /// removeAttr - Remove attributes from an argument.
154 void Argument::removeAttr(AttributeSet AS) {
155 assert(AS.getNumSlots() <= 1 &&
156 "Trying to remove more than one attribute set from an argument!");
157 AttrBuilder B(AS, AS.getSlotIndex(0));
158 getParent()->removeAttributes(getArgNo() + 1,
159 AttributeSet::get(Parent->getContext(),
163 //===----------------------------------------------------------------------===//
164 // Helper Methods in Function
165 //===----------------------------------------------------------------------===//
167 LLVMContext &Function::getContext() const {
168 return getType()->getContext();
171 FunctionType *Function::getFunctionType() const {
172 return cast<FunctionType>(getType()->getElementType());
175 bool Function::isVarArg() const {
176 return getFunctionType()->isVarArg();
179 Type *Function::getReturnType() const {
180 return getFunctionType()->getReturnType();
183 void Function::removeFromParent() {
184 getParent()->getFunctionList().remove(this);
187 void Function::eraseFromParent() {
188 getParent()->getFunctionList().erase(this);
191 //===----------------------------------------------------------------------===//
192 // Function Implementation
193 //===----------------------------------------------------------------------===//
195 Function::Function(FunctionType *Ty, LinkageTypes Linkage,
196 const Twine &name, Module *ParentModule)
197 : GlobalValue(PointerType::getUnqual(Ty),
198 Value::FunctionVal, 0, 0, Linkage, name) {
199 assert(FunctionType::isValidReturnType(getReturnType()) &&
200 "invalid return type");
201 SymTab = new ValueSymbolTable();
203 // If the function has arguments, mark them as lazily built.
204 if (Ty->getNumParams())
205 setValueSubclassData(1); // Set the "has lazy arguments" bit.
207 // Make sure that we get added to a function
208 LeakDetector::addGarbageObject(this);
211 ParentModule->getFunctionList().push_back(this);
213 // Ensure intrinsics have the right parameter attributes.
214 if (unsigned IID = getIntrinsicID())
215 setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID)));
219 Function::~Function() {
220 dropAllReferences(); // After this it is safe to delete instructions.
222 // Delete all of the method arguments and unlink from symbol table...
223 ArgumentList.clear();
226 // Remove the function from the on-the-side GC table.
229 // Remove the intrinsicID from the Cache.
230 if (getValueName() && isIntrinsic())
231 getContext().pImpl->IntrinsicIDCache.erase(this);
234 void Function::BuildLazyArguments() const {
235 // Create the arguments vector, all arguments start out unnamed.
236 FunctionType *FT = getFunctionType();
237 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
238 assert(!FT->getParamType(i)->isVoidTy() &&
239 "Cannot have void typed arguments!");
240 ArgumentList.push_back(new Argument(FT->getParamType(i)));
243 // Clear the lazy arguments bit.
244 unsigned SDC = getSubclassDataFromValue();
245 const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
248 size_t Function::arg_size() const {
249 return getFunctionType()->getNumParams();
251 bool Function::arg_empty() const {
252 return getFunctionType()->getNumParams() == 0;
255 void Function::setParent(Module *parent) {
257 LeakDetector::addGarbageObject(this);
260 LeakDetector::removeGarbageObject(this);
263 // dropAllReferences() - This function causes all the subinstructions to "let
264 // go" of all references that they are maintaining. This allows one to
265 // 'delete' a whole class at a time, even though there may be circular
266 // references... first all references are dropped, and all use counts go to
267 // zero. Then everything is deleted for real. Note that no operations are
268 // valid on an object that has "dropped all references", except operator
271 void Function::dropAllReferences() {
272 for (iterator I = begin(), E = end(); I != E; ++I)
273 I->dropAllReferences();
275 // Delete all basic blocks. They are now unused, except possibly by
276 // blockaddresses, but BasicBlock's destructor takes care of those.
277 while (!BasicBlocks.empty())
278 BasicBlocks.begin()->eraseFromParent();
281 void Function::addAttribute(unsigned i, Attribute::AttrKind attr) {
282 AttributeSet PAL = getAttributes();
283 PAL = PAL.addAttribute(getContext(), i, attr);
287 void Function::addAttributes(unsigned i, AttributeSet attrs) {
288 AttributeSet PAL = getAttributes();
289 PAL = PAL.addAttributes(getContext(), i, attrs);
293 void Function::removeAttributes(unsigned i, AttributeSet attrs) {
294 AttributeSet PAL = getAttributes();
295 PAL = PAL.removeAttributes(getContext(), i, attrs);
299 // Maintain the GC name for each function in an on-the-side table. This saves
300 // allocating an additional word in Function for programs which do not use GC
301 // (i.e., most programs) at the cost of increased overhead for clients which do
303 static DenseMap<const Function*,PooledStringPtr> *GCNames;
304 static StringPool *GCNamePool;
305 static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
307 bool Function::hasGC() const {
308 sys::SmartScopedReader<true> Reader(*GCLock);
309 return GCNames && GCNames->count(this);
312 const char *Function::getGC() const {
313 assert(hasGC() && "Function has no collector");
314 sys::SmartScopedReader<true> Reader(*GCLock);
315 return *(*GCNames)[this];
318 void Function::setGC(const char *Str) {
319 sys::SmartScopedWriter<true> Writer(*GCLock);
321 GCNamePool = new StringPool();
323 GCNames = new DenseMap<const Function*,PooledStringPtr>();
324 (*GCNames)[this] = GCNamePool->intern(Str);
327 void Function::clearGC() {
328 sys::SmartScopedWriter<true> Writer(*GCLock);
330 GCNames->erase(this);
331 if (GCNames->empty()) {
334 if (GCNamePool->empty()) {
342 /// copyAttributesFrom - copy all additional attributes (those not needed to
343 /// create a Function) from the Function Src to this one.
344 void Function::copyAttributesFrom(const GlobalValue *Src) {
345 assert(isa<Function>(Src) && "Expected a Function!");
346 GlobalValue::copyAttributesFrom(Src);
347 const Function *SrcF = cast<Function>(Src);
348 setCallingConv(SrcF->getCallingConv());
349 setAttributes(SrcF->getAttributes());
351 setGC(SrcF->getGC());
356 /// getIntrinsicID - This method returns the ID number of the specified
357 /// function, or Intrinsic::not_intrinsic if the function is not an
358 /// intrinsic, or if the pointer is null. This value is always defined to be
359 /// zero to allow easy checking for whether a function is intrinsic or not. The
360 /// particular intrinsic functions which correspond to this value are defined in
361 /// llvm/Intrinsics.h. Results are cached in the LLVM context, subsequent
362 /// requests for the same ID return results much faster from the cache.
364 unsigned Function::getIntrinsicID() const {
365 const ValueName *ValName = this->getValueName();
366 if (!ValName || !isIntrinsic())
369 LLVMContextImpl::IntrinsicIDCacheTy &IntrinsicIDCache =
370 getContext().pImpl->IntrinsicIDCache;
371 if (!IntrinsicIDCache.count(this)) {
372 unsigned Id = lookupIntrinsicID();
373 IntrinsicIDCache[this]=Id;
376 return IntrinsicIDCache[this];
379 /// This private method does the actual lookup of an intrinsic ID when the query
380 /// could not be answered from the cache.
381 unsigned Function::lookupIntrinsicID() const {
382 const ValueName *ValName = this->getValueName();
383 unsigned Len = ValName->getKeyLength();
384 const char *Name = ValName->getKeyData();
386 #define GET_FUNCTION_RECOGNIZER
387 #include "llvm/IR/Intrinsics.gen"
388 #undef GET_FUNCTION_RECOGNIZER
393 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
394 assert(id < num_intrinsics && "Invalid intrinsic ID!");
395 static const char * const Table[] = {
397 #define GET_INTRINSIC_NAME_TABLE
398 #include "llvm/IR/Intrinsics.gen"
399 #undef GET_INTRINSIC_NAME_TABLE
403 std::string Result(Table[id]);
404 for (unsigned i = 0; i < Tys.size(); ++i) {
405 if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
406 Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
407 EVT::getEVT(PTyp->getElementType()).getEVTString();
410 Result += "." + EVT::getEVT(Tys[i]).getEVTString();
416 /// IIT_Info - These are enumerators that describe the entries returned by the
417 /// getIntrinsicInfoTableEntries function.
419 /// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
421 // Common values should be encoded with 0-15.
439 // Values from 16+ are only encodable with the inefficient encoding.
442 IIT_EMPTYSTRUCT = 18,
447 IIT_EXTEND_VEC_ARG = 23,
448 IIT_TRUNC_VEC_ARG = 24,
453 static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
454 SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
455 IIT_Info Info = IIT_Info(Infos[NextElt++]);
456 unsigned StructElts = 2;
457 using namespace Intrinsic;
461 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
464 OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
467 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
470 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0));
473 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
476 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
479 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
482 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
485 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
488 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
491 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
494 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
495 DecodeIITType(NextElt, Infos, OutputTable);
498 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
499 DecodeIITType(NextElt, Infos, OutputTable);
502 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
503 DecodeIITType(NextElt, Infos, OutputTable);
506 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
507 DecodeIITType(NextElt, Infos, OutputTable);
510 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
511 DecodeIITType(NextElt, Infos, OutputTable);
514 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
515 DecodeIITType(NextElt, Infos, OutputTable);
517 case IIT_ANYPTR: { // [ANYPTR addrspace, subtype]
518 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
520 DecodeIITType(NextElt, Infos, OutputTable);
524 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
525 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
528 case IIT_EXTEND_VEC_ARG: {
529 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
530 OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument,
534 case IIT_TRUNC_VEC_ARG: {
535 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
536 OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument,
540 case IIT_EMPTYSTRUCT:
541 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
543 case IIT_STRUCT5: ++StructElts; // FALL THROUGH.
544 case IIT_STRUCT4: ++StructElts; // FALL THROUGH.
545 case IIT_STRUCT3: ++StructElts; // FALL THROUGH.
547 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
549 for (unsigned i = 0; i != StructElts; ++i)
550 DecodeIITType(NextElt, Infos, OutputTable);
554 llvm_unreachable("unhandled");
558 #define GET_INTRINSIC_GENERATOR_GLOBAL
559 #include "llvm/IR/Intrinsics.gen"
560 #undef GET_INTRINSIC_GENERATOR_GLOBAL
562 void Intrinsic::getIntrinsicInfoTableEntries(ID id,
563 SmallVectorImpl<IITDescriptor> &T){
564 // Check to see if the intrinsic's type was expressible by the table.
565 unsigned TableVal = IIT_Table[id-1];
567 // Decode the TableVal into an array of IITValues.
568 SmallVector<unsigned char, 8> IITValues;
569 ArrayRef<unsigned char> IITEntries;
570 unsigned NextElt = 0;
571 if ((TableVal >> 31) != 0) {
572 // This is an offset into the IIT_LongEncodingTable.
573 IITEntries = IIT_LongEncodingTable;
575 // Strip sentinel bit.
576 NextElt = (TableVal << 1) >> 1;
578 // Decode the TableVal into an array of IITValues. If the entry was encoded
579 // into a single word in the table itself, decode it now.
581 IITValues.push_back(TableVal & 0xF);
585 IITEntries = IITValues;
589 // Okay, decode the table into the output vector of IITDescriptors.
590 DecodeIITType(NextElt, IITEntries, T);
591 while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
592 DecodeIITType(NextElt, IITEntries, T);
596 static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
597 ArrayRef<Type*> Tys, LLVMContext &Context) {
598 using namespace Intrinsic;
599 IITDescriptor D = Infos.front();
600 Infos = Infos.slice(1);
603 case IITDescriptor::Void: return Type::getVoidTy(Context);
604 case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
605 case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
606 case IITDescriptor::Half: return Type::getHalfTy(Context);
607 case IITDescriptor::Float: return Type::getFloatTy(Context);
608 case IITDescriptor::Double: return Type::getDoubleTy(Context);
610 case IITDescriptor::Integer:
611 return IntegerType::get(Context, D.Integer_Width);
612 case IITDescriptor::Vector:
613 return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
614 case IITDescriptor::Pointer:
615 return PointerType::get(DecodeFixedType(Infos, Tys, Context),
616 D.Pointer_AddressSpace);
617 case IITDescriptor::Struct: {
619 assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
620 for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
621 Elts[i] = DecodeFixedType(Infos, Tys, Context);
622 return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements));
625 case IITDescriptor::Argument:
626 return Tys[D.getArgumentNumber()];
627 case IITDescriptor::ExtendVecArgument:
628 return VectorType::getExtendedElementVectorType(cast<VectorType>(
629 Tys[D.getArgumentNumber()]));
631 case IITDescriptor::TruncVecArgument:
632 return VectorType::getTruncatedElementVectorType(cast<VectorType>(
633 Tys[D.getArgumentNumber()]));
635 llvm_unreachable("unhandled");
640 FunctionType *Intrinsic::getType(LLVMContext &Context,
641 ID id, ArrayRef<Type*> Tys) {
642 SmallVector<IITDescriptor, 8> Table;
643 getIntrinsicInfoTableEntries(id, Table);
645 ArrayRef<IITDescriptor> TableRef = Table;
646 Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
648 SmallVector<Type*, 8> ArgTys;
649 while (!TableRef.empty())
650 ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
652 return FunctionType::get(ResultTy, ArgTys, false);
655 bool Intrinsic::isOverloaded(ID id) {
656 #define GET_INTRINSIC_OVERLOAD_TABLE
657 #include "llvm/IR/Intrinsics.gen"
658 #undef GET_INTRINSIC_OVERLOAD_TABLE
661 /// This defines the "Intrinsic::getAttributes(ID id)" method.
662 #define GET_INTRINSIC_ATTRIBUTES
663 #include "llvm/IR/Intrinsics.gen"
664 #undef GET_INTRINSIC_ATTRIBUTES
666 Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
667 // There can never be multiple globals with the same name of different types,
668 // because intrinsics must be a specific type.
670 cast<Function>(M->getOrInsertFunction(getName(id, Tys),
671 getType(M->getContext(), id, Tys)));
674 // This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
675 #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
676 #include "llvm/IR/Intrinsics.gen"
677 #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
679 /// hasAddressTaken - returns true if there are any uses of this function
680 /// other than direct calls or invokes to it.
681 bool Function::hasAddressTaken(const User* *PutOffender) const {
682 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
684 if (isa<BlockAddress>(U))
686 if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
687 return PutOffender ? (*PutOffender = U, true) : true;
688 ImmutableCallSite CS(cast<Instruction>(U));
690 return PutOffender ? (*PutOffender = U, true) : true;
695 bool Function::isDefTriviallyDead() const {
697 if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
698 !hasAvailableExternallyLinkage())
701 // Check if the function is used by anything other than a blockaddress.
702 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I)
703 if (!isa<BlockAddress>(*I))
709 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
710 /// setjmp or other function that gcc recognizes as "returning twice".
711 bool Function::callsFunctionThatReturnsTwice() const {
712 for (const_inst_iterator
713 I = inst_begin(this), E = inst_end(this); I != E; ++I) {
714 const CallInst* callInst = dyn_cast<CallInst>(&*I);
717 if (callInst->canReturnTwice())