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 /// addAttr - Add attributes to an argument.
128 void Argument::addAttr(AttributeSet AS) {
129 assert(AS.getNumSlots() <= 1 &&
130 "Trying to add more than one attribute set to an argument!");
131 AttrBuilder B(AS, AS.getSlotIndex(0));
132 getParent()->addAttributes(getArgNo() + 1,
133 AttributeSet::get(Parent->getContext(),
137 /// removeAttr - Remove attributes from an argument.
138 void Argument::removeAttr(AttributeSet AS) {
139 assert(AS.getNumSlots() <= 1 &&
140 "Trying to remove more than one attribute set from an argument!");
141 AttrBuilder B(AS, AS.getSlotIndex(0));
142 getParent()->removeAttributes(getArgNo() + 1,
143 AttributeSet::get(Parent->getContext(),
147 //===----------------------------------------------------------------------===//
148 // Helper Methods in Function
149 //===----------------------------------------------------------------------===//
151 LLVMContext &Function::getContext() const {
152 return getType()->getContext();
155 FunctionType *Function::getFunctionType() const {
156 return cast<FunctionType>(getType()->getElementType());
159 bool Function::isVarArg() const {
160 return getFunctionType()->isVarArg();
163 Type *Function::getReturnType() const {
164 return getFunctionType()->getReturnType();
167 void Function::removeFromParent() {
168 getParent()->getFunctionList().remove(this);
171 void Function::eraseFromParent() {
172 getParent()->getFunctionList().erase(this);
175 //===----------------------------------------------------------------------===//
176 // Function Implementation
177 //===----------------------------------------------------------------------===//
179 Function::Function(FunctionType *Ty, LinkageTypes Linkage,
180 const Twine &name, Module *ParentModule)
181 : GlobalValue(PointerType::getUnqual(Ty),
182 Value::FunctionVal, 0, 0, Linkage, name) {
183 assert(FunctionType::isValidReturnType(getReturnType()) &&
184 "invalid return type");
185 SymTab = new ValueSymbolTable();
187 // If the function has arguments, mark them as lazily built.
188 if (Ty->getNumParams())
189 setValueSubclassData(1); // Set the "has lazy arguments" bit.
191 // Make sure that we get added to a function
192 LeakDetector::addGarbageObject(this);
195 ParentModule->getFunctionList().push_back(this);
197 // Ensure intrinsics have the right parameter attributes.
198 if (unsigned IID = getIntrinsicID())
199 setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID)));
203 Function::~Function() {
204 dropAllReferences(); // After this it is safe to delete instructions.
206 // Delete all of the method arguments and unlink from symbol table...
207 ArgumentList.clear();
210 // Remove the function from the on-the-side GC table.
213 // Remove the intrinsicID from the Cache.
214 if(getValueName() && isIntrinsic())
215 getContext().pImpl->IntrinsicIDCache.erase(this);
218 void Function::BuildLazyArguments() const {
219 // Create the arguments vector, all arguments start out unnamed.
220 FunctionType *FT = getFunctionType();
221 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
222 assert(!FT->getParamType(i)->isVoidTy() &&
223 "Cannot have void typed arguments!");
224 ArgumentList.push_back(new Argument(FT->getParamType(i)));
227 // Clear the lazy arguments bit.
228 unsigned SDC = getSubclassDataFromValue();
229 const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
232 size_t Function::arg_size() const {
233 return getFunctionType()->getNumParams();
235 bool Function::arg_empty() const {
236 return getFunctionType()->getNumParams() == 0;
239 void Function::setParent(Module *parent) {
241 LeakDetector::addGarbageObject(this);
244 LeakDetector::removeGarbageObject(this);
247 // dropAllReferences() - This function causes all the subinstructions to "let
248 // go" of all references that they are maintaining. This allows one to
249 // 'delete' a whole class at a time, even though there may be circular
250 // references... first all references are dropped, and all use counts go to
251 // zero. Then everything is deleted for real. Note that no operations are
252 // valid on an object that has "dropped all references", except operator
255 void Function::dropAllReferences() {
256 for (iterator I = begin(), E = end(); I != E; ++I)
257 I->dropAllReferences();
259 // Delete all basic blocks. They are now unused, except possibly by
260 // blockaddresses, but BasicBlock's destructor takes care of those.
261 while (!BasicBlocks.empty())
262 BasicBlocks.begin()->eraseFromParent();
265 void Function::addAttribute(unsigned i, Attribute::AttrKind attr) {
266 AttributeSet PAL = getAttributes();
267 PAL = PAL.addAttribute(getContext(), i, attr);
271 void Function::addAttributes(unsigned i, AttributeSet attrs) {
272 AttributeSet PAL = getAttributes();
273 PAL = PAL.addAttributes(getContext(), i, attrs);
277 void Function::removeAttributes(unsigned i, AttributeSet attrs) {
278 AttributeSet PAL = getAttributes();
279 PAL = PAL.removeAttributes(getContext(), i, attrs);
283 // Maintain the GC name for each function in an on-the-side table. This saves
284 // allocating an additional word in Function for programs which do not use GC
285 // (i.e., most programs) at the cost of increased overhead for clients which do
287 static DenseMap<const Function*,PooledStringPtr> *GCNames;
288 static StringPool *GCNamePool;
289 static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
291 bool Function::hasGC() const {
292 sys::SmartScopedReader<true> Reader(*GCLock);
293 return GCNames && GCNames->count(this);
296 const char *Function::getGC() const {
297 assert(hasGC() && "Function has no collector");
298 sys::SmartScopedReader<true> Reader(*GCLock);
299 return *(*GCNames)[this];
302 void Function::setGC(const char *Str) {
303 sys::SmartScopedWriter<true> Writer(*GCLock);
305 GCNamePool = new StringPool();
307 GCNames = new DenseMap<const Function*,PooledStringPtr>();
308 (*GCNames)[this] = GCNamePool->intern(Str);
311 void Function::clearGC() {
312 sys::SmartScopedWriter<true> Writer(*GCLock);
314 GCNames->erase(this);
315 if (GCNames->empty()) {
318 if (GCNamePool->empty()) {
326 /// copyAttributesFrom - copy all additional attributes (those not needed to
327 /// create a Function) from the Function Src to this one.
328 void Function::copyAttributesFrom(const GlobalValue *Src) {
329 assert(isa<Function>(Src) && "Expected a Function!");
330 GlobalValue::copyAttributesFrom(Src);
331 const Function *SrcF = cast<Function>(Src);
332 setCallingConv(SrcF->getCallingConv());
333 setAttributes(SrcF->getAttributes());
335 setGC(SrcF->getGC());
340 /// getIntrinsicID - This method returns the ID number of the specified
341 /// function, or Intrinsic::not_intrinsic if the function is not an
342 /// intrinsic, or if the pointer is null. This value is always defined to be
343 /// zero to allow easy checking for whether a function is intrinsic or not. The
344 /// particular intrinsic functions which correspond to this value are defined in
345 /// llvm/Intrinsics.h. Results are cached in the LLVM context, subsequent
346 /// requests for the same ID return results much faster from the cache.
348 unsigned Function::getIntrinsicID() const {
349 const ValueName *ValName = this->getValueName();
350 if (!ValName || !isIntrinsic())
353 LLVMContextImpl::IntrinsicIDCacheTy &IntrinsicIDCache =
354 getContext().pImpl->IntrinsicIDCache;
355 if(!IntrinsicIDCache.count(this)) {
356 unsigned Id = lookupIntrinsicID();
357 IntrinsicIDCache[this]=Id;
360 return IntrinsicIDCache[this];
363 /// This private method does the actual lookup of an intrinsic ID when the query
364 /// could not be answered from the cache.
365 unsigned Function::lookupIntrinsicID() const {
366 const ValueName *ValName = this->getValueName();
367 unsigned Len = ValName->getKeyLength();
368 const char *Name = ValName->getKeyData();
370 #define GET_FUNCTION_RECOGNIZER
371 #include "llvm/IR/Intrinsics.gen"
372 #undef GET_FUNCTION_RECOGNIZER
377 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
378 assert(id < num_intrinsics && "Invalid intrinsic ID!");
379 static const char * const Table[] = {
381 #define GET_INTRINSIC_NAME_TABLE
382 #include "llvm/IR/Intrinsics.gen"
383 #undef GET_INTRINSIC_NAME_TABLE
387 std::string Result(Table[id]);
388 for (unsigned i = 0; i < Tys.size(); ++i) {
389 if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
390 Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
391 EVT::getEVT(PTyp->getElementType()).getEVTString();
394 Result += "." + EVT::getEVT(Tys[i]).getEVTString();
400 /// IIT_Info - These are enumerators that describe the entries returned by the
401 /// getIntrinsicInfoTableEntries function.
403 /// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
405 // Common values should be encoded with 0-15.
423 // Values from 16+ are only encodable with the inefficient encoding.
426 IIT_EMPTYSTRUCT = 18,
431 IIT_EXTEND_VEC_ARG = 23,
432 IIT_TRUNC_VEC_ARG = 24,
437 static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
438 SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
439 IIT_Info Info = IIT_Info(Infos[NextElt++]);
440 unsigned StructElts = 2;
441 using namespace Intrinsic;
445 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
448 OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
451 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
454 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Half, 0));
457 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
460 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
463 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
466 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
469 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
472 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
475 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
478 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
479 DecodeIITType(NextElt, Infos, OutputTable);
482 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
483 DecodeIITType(NextElt, Infos, OutputTable);
486 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
487 DecodeIITType(NextElt, Infos, OutputTable);
490 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
491 DecodeIITType(NextElt, Infos, OutputTable);
494 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
495 DecodeIITType(NextElt, Infos, OutputTable);
498 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
499 DecodeIITType(NextElt, Infos, OutputTable);
501 case IIT_ANYPTR: { // [ANYPTR addrspace, subtype]
502 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
504 DecodeIITType(NextElt, Infos, OutputTable);
508 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
509 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
512 case IIT_EXTEND_VEC_ARG: {
513 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
514 OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument,
518 case IIT_TRUNC_VEC_ARG: {
519 unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
520 OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument,
524 case IIT_EMPTYSTRUCT:
525 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
527 case IIT_STRUCT5: ++StructElts; // FALL THROUGH.
528 case IIT_STRUCT4: ++StructElts; // FALL THROUGH.
529 case IIT_STRUCT3: ++StructElts; // FALL THROUGH.
531 OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
533 for (unsigned i = 0; i != StructElts; ++i)
534 DecodeIITType(NextElt, Infos, OutputTable);
538 llvm_unreachable("unhandled");
542 #define GET_INTRINSIC_GENERATOR_GLOBAL
543 #include "llvm/IR/Intrinsics.gen"
544 #undef GET_INTRINSIC_GENERATOR_GLOBAL
546 void Intrinsic::getIntrinsicInfoTableEntries(ID id,
547 SmallVectorImpl<IITDescriptor> &T){
548 // Check to see if the intrinsic's type was expressible by the table.
549 unsigned TableVal = IIT_Table[id-1];
551 // Decode the TableVal into an array of IITValues.
552 SmallVector<unsigned char, 8> IITValues;
553 ArrayRef<unsigned char> IITEntries;
554 unsigned NextElt = 0;
555 if ((TableVal >> 31) != 0) {
556 // This is an offset into the IIT_LongEncodingTable.
557 IITEntries = IIT_LongEncodingTable;
559 // Strip sentinel bit.
560 NextElt = (TableVal << 1) >> 1;
562 // Decode the TableVal into an array of IITValues. If the entry was encoded
563 // into a single word in the table itself, decode it now.
565 IITValues.push_back(TableVal & 0xF);
569 IITEntries = IITValues;
573 // Okay, decode the table into the output vector of IITDescriptors.
574 DecodeIITType(NextElt, IITEntries, T);
575 while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
576 DecodeIITType(NextElt, IITEntries, T);
580 static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
581 ArrayRef<Type*> Tys, LLVMContext &Context) {
582 using namespace Intrinsic;
583 IITDescriptor D = Infos.front();
584 Infos = Infos.slice(1);
587 case IITDescriptor::Void: return Type::getVoidTy(Context);
588 case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
589 case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
590 case IITDescriptor::Half: return Type::getHalfTy(Context);
591 case IITDescriptor::Float: return Type::getFloatTy(Context);
592 case IITDescriptor::Double: return Type::getDoubleTy(Context);
594 case IITDescriptor::Integer:
595 return IntegerType::get(Context, D.Integer_Width);
596 case IITDescriptor::Vector:
597 return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
598 case IITDescriptor::Pointer:
599 return PointerType::get(DecodeFixedType(Infos, Tys, Context),
600 D.Pointer_AddressSpace);
601 case IITDescriptor::Struct: {
603 assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
604 for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
605 Elts[i] = DecodeFixedType(Infos, Tys, Context);
606 return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements));
609 case IITDescriptor::Argument:
610 return Tys[D.getArgumentNumber()];
611 case IITDescriptor::ExtendVecArgument:
612 return VectorType::getExtendedElementVectorType(cast<VectorType>(
613 Tys[D.getArgumentNumber()]));
615 case IITDescriptor::TruncVecArgument:
616 return VectorType::getTruncatedElementVectorType(cast<VectorType>(
617 Tys[D.getArgumentNumber()]));
619 llvm_unreachable("unhandled");
624 FunctionType *Intrinsic::getType(LLVMContext &Context,
625 ID id, ArrayRef<Type*> Tys) {
626 SmallVector<IITDescriptor, 8> Table;
627 getIntrinsicInfoTableEntries(id, Table);
629 ArrayRef<IITDescriptor> TableRef = Table;
630 Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
632 SmallVector<Type*, 8> ArgTys;
633 while (!TableRef.empty())
634 ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
636 return FunctionType::get(ResultTy, ArgTys, false);
639 bool Intrinsic::isOverloaded(ID id) {
640 #define GET_INTRINSIC_OVERLOAD_TABLE
641 #include "llvm/IR/Intrinsics.gen"
642 #undef GET_INTRINSIC_OVERLOAD_TABLE
645 /// This defines the "Intrinsic::getAttributes(ID id)" method.
646 #define GET_INTRINSIC_ATTRIBUTES
647 #include "llvm/IR/Intrinsics.gen"
648 #undef GET_INTRINSIC_ATTRIBUTES
650 Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
651 // There can never be multiple globals with the same name of different types,
652 // because intrinsics must be a specific type.
654 cast<Function>(M->getOrInsertFunction(getName(id, Tys),
655 getType(M->getContext(), id, Tys)));
658 // This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
659 #define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
660 #include "llvm/IR/Intrinsics.gen"
661 #undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
663 /// hasAddressTaken - returns true if there are any uses of this function
664 /// other than direct calls or invokes to it.
665 bool Function::hasAddressTaken(const User* *PutOffender) const {
666 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
668 if (isa<BlockAddress>(U))
670 if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
671 return PutOffender ? (*PutOffender = U, true) : true;
672 ImmutableCallSite CS(cast<Instruction>(U));
674 return PutOffender ? (*PutOffender = U, true) : true;
679 bool Function::isDefTriviallyDead() const {
681 if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
682 !hasAvailableExternallyLinkage())
685 // Check if the function is used by anything other than a blockaddress.
686 for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I)
687 if (!isa<BlockAddress>(*I))
693 /// callsFunctionThatReturnsTwice - Return true if the function has a call to
694 /// setjmp or other function that gcc recognizes as "returning twice".
695 bool Function::callsFunctionThatReturnsTwice() const {
696 for (const_inst_iterator
697 I = inst_begin(this), E = inst_end(this); I != E; ++I) {
698 const CallInst* callInst = dyn_cast<CallInst>(&*I);
701 if (callInst->canReturnTwice())