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 /// addAttr - Add attributes to an argument.
135 void Argument::addAttr(AttributeSet AS) {
136 assert(AS.getNumSlots() <= 1 &&
137 "Trying to add more than one attribute set to an argument!");
138 AttrBuilder B(AS, AS.getSlotIndex(0));
139 getParent()->addAttributes(getArgNo() + 1,
140 AttributeSet::get(Parent->getContext(),
144 /// removeAttr - Remove attributes from an argument.
145 void Argument::removeAttr(AttributeSet AS) {
146 assert(AS.getNumSlots() <= 1 &&
147 "Trying to remove more than one attribute set from an argument!");
148 AttrBuilder B(AS, AS.getSlotIndex(0));
149 getParent()->removeAttributes(getArgNo() + 1,
150 AttributeSet::get(Parent->getContext(),
154 //===----------------------------------------------------------------------===//
155 // Helper Methods in Function
156 //===----------------------------------------------------------------------===//
158 LLVMContext &Function::getContext() const {
159 return getType()->getContext();
162 FunctionType *Function::getFunctionType() const {
163 return cast<FunctionType>(getType()->getElementType());
166 bool Function::isVarArg() const {
167 return getFunctionType()->isVarArg();
170 Type *Function::getReturnType() const {
171 return getFunctionType()->getReturnType();
174 void Function::removeFromParent() {
175 getParent()->getFunctionList().remove(this);
178 void Function::eraseFromParent() {
179 getParent()->getFunctionList().erase(this);
182 //===----------------------------------------------------------------------===//
183 // Function Implementation
184 //===----------------------------------------------------------------------===//
186 Function::Function(FunctionType *Ty, LinkageTypes Linkage,
187 const Twine &name, Module *ParentModule)
188 : GlobalValue(PointerType::getUnqual(Ty),
189 Value::FunctionVal, 0, 0, Linkage, name) {
190 assert(FunctionType::isValidReturnType(getReturnType()) &&
191 "invalid return type");
192 SymTab = new ValueSymbolTable();
194 // If the function has arguments, mark them as lazily built.
195 if (Ty->getNumParams())
196 setValueSubclassData(1); // Set the "has lazy arguments" bit.
198 // Make sure that we get added to a function
199 LeakDetector::addGarbageObject(this);
202 ParentModule->getFunctionList().push_back(this);
204 // Ensure intrinsics have the right parameter attributes.
205 if (unsigned IID = getIntrinsicID())
206 setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID)));
210 Function::~Function() {
211 dropAllReferences(); // After this it is safe to delete instructions.
213 // Delete all of the method arguments and unlink from symbol table...
214 ArgumentList.clear();
217 // Remove the function from the on-the-side GC table.
220 // Remove the intrinsicID from the Cache.
221 if (getValueName() && isIntrinsic())
222 getContext().pImpl->IntrinsicIDCache.erase(this);
225 void Function::BuildLazyArguments() const {
226 // Create the arguments vector, all arguments start out unnamed.
227 FunctionType *FT = getFunctionType();
228 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
229 assert(!FT->getParamType(i)->isVoidTy() &&
230 "Cannot have void typed arguments!");
231 ArgumentList.push_back(new Argument(FT->getParamType(i)));
234 // Clear the lazy arguments bit.
235 unsigned SDC = getSubclassDataFromValue();
236 const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
239 size_t Function::arg_size() const {
240 return getFunctionType()->getNumParams();
242 bool Function::arg_empty() const {
243 return getFunctionType()->getNumParams() == 0;
246 void Function::setParent(Module *parent) {
248 LeakDetector::addGarbageObject(this);
251 LeakDetector::removeGarbageObject(this);
254 // dropAllReferences() - This function causes all the subinstructions to "let
255 // go" of all references that they are maintaining. This allows one to
256 // 'delete' a whole class at a time, even though there may be circular
257 // references... first all references are dropped, and all use counts go to
258 // zero. Then everything is deleted for real. Note that no operations are
259 // valid on an object that has "dropped all references", except operator
262 void Function::dropAllReferences() {
263 for (iterator I = begin(), E = end(); I != E; ++I)
264 I->dropAllReferences();
266 // Delete all basic blocks. They are now unused, except possibly by
267 // blockaddresses, but BasicBlock's destructor takes care of those.
268 while (!BasicBlocks.empty())
269 BasicBlocks.begin()->eraseFromParent();
272 void Function::addAttribute(unsigned i, Attribute::AttrKind attr) {
273 AttributeSet PAL = getAttributes();
274 PAL = PAL.addAttribute(getContext(), i, attr);
278 void Function::addAttributes(unsigned i, AttributeSet attrs) {
279 AttributeSet PAL = getAttributes();
280 PAL = PAL.addAttributes(getContext(), i, attrs);
284 void Function::removeAttributes(unsigned i, AttributeSet attrs) {
285 AttributeSet PAL = getAttributes();
286 PAL = PAL.removeAttributes(getContext(), i, attrs);
290 // Maintain the GC name for each function in an on-the-side table. This saves
291 // allocating an additional word in Function for programs which do not use GC
292 // (i.e., most programs) at the cost of increased overhead for clients which do
294 static DenseMap<const Function*,PooledStringPtr> *GCNames;
295 static StringPool *GCNamePool;
296 static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
298 bool Function::hasGC() const {
299 sys::SmartScopedReader<true> Reader(*GCLock);
300 return GCNames && GCNames->count(this);
303 const char *Function::getGC() const {
304 assert(hasGC() && "Function has no collector");
305 sys::SmartScopedReader<true> Reader(*GCLock);
306 return *(*GCNames)[this];
309 void Function::setGC(const char *Str) {
310 sys::SmartScopedWriter<true> Writer(*GCLock);
312 GCNamePool = new StringPool();
314 GCNames = new DenseMap<const Function*,PooledStringPtr>();
315 (*GCNames)[this] = GCNamePool->intern(Str);
318 void Function::clearGC() {
319 sys::SmartScopedWriter<true> Writer(*GCLock);
321 GCNames->erase(this);
322 if (GCNames->empty()) {
325 if (GCNamePool->empty()) {
333 /// copyAttributesFrom - copy all additional attributes (those not needed to
334 /// create a Function) from the Function Src to this one.
335 void Function::copyAttributesFrom(const GlobalValue *Src) {
336 assert(isa<Function>(Src) && "Expected a Function!");
337 GlobalValue::copyAttributesFrom(Src);
338 const Function *SrcF = cast<Function>(Src);
339 setCallingConv(SrcF->getCallingConv());
340 setAttributes(SrcF->getAttributes());
342 setGC(SrcF->getGC());
347 /// getIntrinsicID - This method returns the ID number of the specified
348 /// function, or Intrinsic::not_intrinsic if the function is not an
349 /// intrinsic, or if the pointer is null. This value is always defined to be
350 /// zero to allow easy checking for whether a function is intrinsic or not. The
351 /// particular intrinsic functions which correspond to this value are defined in
352 /// llvm/Intrinsics.h. Results are cached in the LLVM context, subsequent
353 /// requests for the same ID return results much faster from the cache.
355 unsigned Function::getIntrinsicID() const {
356 const ValueName *ValName = this->getValueName();
357 if (!ValName || !isIntrinsic())
360 LLVMContextImpl::IntrinsicIDCacheTy &IntrinsicIDCache =
361 getContext().pImpl->IntrinsicIDCache;
362 if (!IntrinsicIDCache.count(this)) {
363 unsigned Id = lookupIntrinsicID();
364 IntrinsicIDCache[this]=Id;
367 return IntrinsicIDCache[this];
370 /// This private method does the actual lookup of an intrinsic ID when the query
371 /// could not be answered from the cache.
372 unsigned Function::lookupIntrinsicID() const {
373 const ValueName *ValName = this->getValueName();
374 unsigned Len = ValName->getKeyLength();
375 const char *Name = ValName->getKeyData();
377 #define GET_FUNCTION_RECOGNIZER
378 #include "llvm/IR/Intrinsics.gen"
379 #undef GET_FUNCTION_RECOGNIZER
384 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
385 assert(id < num_intrinsics && "Invalid intrinsic ID!");
386 static const char * const Table[] = {
388 #define GET_INTRINSIC_NAME_TABLE
389 #include "llvm/IR/Intrinsics.gen"
390 #undef GET_INTRINSIC_NAME_TABLE
394 std::string Result(Table[id]);
395 for (unsigned i = 0; i < Tys.size(); ++i) {
396 if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
397 Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
398 EVT::getEVT(PTyp->getElementType()).getEVTString();
401 Result += "." + EVT::getEVT(Tys[i]).getEVTString();
407 /// IIT_Info - These are enumerators that describe the entries returned by the
408 /// getIntrinsicInfoTableEntries function.
410 /// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
412 // Common values should be encoded with 0-15.
430 // Values from 16+ are only encodable with the inefficient encoding.
433 IIT_EMPTYSTRUCT = 18,
438 IIT_EXTEND_VEC_ARG = 23,
439 IIT_TRUNC_VEC_ARG = 24,
444 static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
445 SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
446 IIT_Info Info = IIT_Info(Infos[NextElt++]);
447 unsigned StructElts = 2;
448 using namespace Intrinsic;
452 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
455 OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
458 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
461 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0));
464 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
467 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
470 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
473 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
476 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
479 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
482 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
485 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
486 DecodeIITType(NextElt, Infos, OutputTable);
489 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
490 DecodeIITType(NextElt, Infos, OutputTable);
493 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
494 DecodeIITType(NextElt, Infos, OutputTable);
497 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
498 DecodeIITType(NextElt, Infos, OutputTable);
501 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
502 DecodeIITType(NextElt, Infos, OutputTable);
505 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
506 DecodeIITType(NextElt, Infos, OutputTable);
508 case IIT_ANYPTR: { // [ANYPTR addrspace, subtype]
509 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
511 DecodeIITType(NextElt, Infos, OutputTable);
515 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
516 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
519 case IIT_EXTEND_VEC_ARG: {
520 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
521 OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument,
525 case IIT_TRUNC_VEC_ARG: {
526 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
527 OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument,
531 case IIT_EMPTYSTRUCT:
532 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
534 case IIT_STRUCT5: ++StructElts; // FALL THROUGH.
535 case IIT_STRUCT4: ++StructElts; // FALL THROUGH.
536 case IIT_STRUCT3: ++StructElts; // FALL THROUGH.
538 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
540 for (unsigned i = 0; i != StructElts; ++i)
541 DecodeIITType(NextElt, Infos, OutputTable);
545 llvm_unreachable("unhandled");
549 #define GET_INTRINSIC_GENERATOR_GLOBAL
550 #include "llvm/IR/Intrinsics.gen"
551 #undef GET_INTRINSIC_GENERATOR_GLOBAL
553 void Intrinsic::getIntrinsicInfoTableEntries(ID id,
554 SmallVectorImpl<IITDescriptor> &T){
555 // Check to see if the intrinsic's type was expressible by the table.
556 unsigned TableVal = IIT_Table[id-1];
558 // Decode the TableVal into an array of IITValues.
559 SmallVector<unsigned char, 8> IITValues;
560 ArrayRef<unsigned char> IITEntries;
561 unsigned NextElt = 0;
562 if ((TableVal >> 31) != 0) {
563 // This is an offset into the IIT_LongEncodingTable.
564 IITEntries = IIT_LongEncodingTable;
566 // Strip sentinel bit.
567 NextElt = (TableVal << 1) >> 1;
569 // Decode the TableVal into an array of IITValues. If the entry was encoded
570 // into a single word in the table itself, decode it now.
572 IITValues.push_back(TableVal & 0xF);
576 IITEntries = IITValues;
580 // Okay, decode the table into the output vector of IITDescriptors.
581 DecodeIITType(NextElt, IITEntries, T);
582 while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
583 DecodeIITType(NextElt, IITEntries, T);
587 static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
588 ArrayRef<Type*> Tys, LLVMContext &Context) {
589 using namespace Intrinsic;
590 IITDescriptor D = Infos.front();
591 Infos = Infos.slice(1);
594 case IITDescriptor::Void: return Type::getVoidTy(Context);
595 case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
596 case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
597 case IITDescriptor::Half: return Type::getHalfTy(Context);
598 case IITDescriptor::Float: return Type::getFloatTy(Context);
599 case IITDescriptor::Double: return Type::getDoubleTy(Context);
601 case IITDescriptor::Integer:
602 return IntegerType::get(Context, D.Integer_Width);
603 case IITDescriptor::Vector:
604 return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
605 case IITDescriptor::Pointer:
606 return PointerType::get(DecodeFixedType(Infos, Tys, Context),
607 D.Pointer_AddressSpace);
608 case IITDescriptor::Struct: {
610 assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
611 for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
612 Elts[i] = DecodeFixedType(Infos, Tys, Context);
613 return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements));
616 case IITDescriptor::Argument:
617 return Tys[D.getArgumentNumber()];
618 case IITDescriptor::ExtendVecArgument:
619 return VectorType::getExtendedElementVectorType(cast<VectorType>(
620 Tys[D.getArgumentNumber()]));
622 case IITDescriptor::TruncVecArgument:
623 return VectorType::getTruncatedElementVectorType(cast<VectorType>(
624 Tys[D.getArgumentNumber()]));
626 llvm_unreachable("unhandled");
631 FunctionType *Intrinsic::getType(LLVMContext &Context,
632 ID id, ArrayRef<Type*> Tys) {
633 SmallVector<IITDescriptor, 8> Table;
634 getIntrinsicInfoTableEntries(id, Table);
636 ArrayRef<IITDescriptor> TableRef = Table;
637 Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
639 SmallVector<Type*, 8> ArgTys;
640 while (!TableRef.empty())
641 ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
643 return FunctionType::get(ResultTy, ArgTys, false);
646 bool Intrinsic::isOverloaded(ID id) {
647 #define GET_INTRINSIC_OVERLOAD_TABLE
648 #include "llvm/IR/Intrinsics.gen"
649 #undef GET_INTRINSIC_OVERLOAD_TABLE
652 /// This defines the "Intrinsic::getAttributes(ID id)" method.
653 #define GET_INTRINSIC_ATTRIBUTES
654 #include "llvm/IR/Intrinsics.gen"
655 #undef GET_INTRINSIC_ATTRIBUTES
657 Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
658 // There can never be multiple globals with the same name of different types,
659 // because intrinsics must be a specific type.
661 cast<Function>(M->getOrInsertFunction(getName(id, Tys),
662 getType(M->getContext(), id, Tys)));
665 // This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
666 #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
667 #include "llvm/IR/Intrinsics.gen"
668 #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
670 /// hasAddressTaken - returns true if there are any uses of this function
671 /// other than direct calls or invokes to it.
672 bool Function::hasAddressTaken(const User* *PutOffender) const {
673 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
675 if (isa<BlockAddress>(U))
677 if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
678 return PutOffender ? (*PutOffender = U, true) : true;
679 ImmutableCallSite CS(cast<Instruction>(U));
681 return PutOffender ? (*PutOffender = U, true) : true;
686 bool Function::isDefTriviallyDead() const {
688 if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
689 !hasAvailableExternallyLinkage())
692 // Check if the function is used by anything other than a blockaddress.
693 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I)
694 if (!isa<BlockAddress>(*I))
700 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
701 /// setjmp or other function that gcc recognizes as "returning twice".
702 bool Function::callsFunctionThatReturnsTwice() const {
703 for (const_inst_iterator
704 I = inst_begin(this), E = inst_end(this); I != E; ++I) {
705 const CallInst* callInst = dyn_cast<CallInst>(&*I);
708 if (callInst->canReturnTwice())