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 VMCore library.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Module.h"
15 #include "llvm/DerivedTypes.h"
16 #include "llvm/IntrinsicInst.h"
17 #include "llvm/ParamAttrsList.h"
18 #include "llvm/CodeGen/ValueTypes.h"
19 #include "llvm/Support/LeakDetector.h"
20 #include "llvm/Support/StringPool.h"
21 #include "SymbolTableListTraitsImpl.h"
22 #include "llvm/ADT/BitVector.h"
23 #include "llvm/ADT/DenseMap.h"
24 #include "llvm/ADT/StringExtras.h"
27 BasicBlock *ilist_traits<BasicBlock>::createSentinel() {
28 BasicBlock *Ret = new BasicBlock();
29 // This should not be garbage monitored.
30 LeakDetector::removeGarbageObject(Ret);
34 iplist<BasicBlock> &ilist_traits<BasicBlock>::getList(Function *F) {
35 return F->getBasicBlockList();
38 Argument *ilist_traits<Argument>::createSentinel() {
39 Argument *Ret = new Argument(Type::Int32Ty);
40 // This should not be garbage monitored.
41 LeakDetector::removeGarbageObject(Ret);
45 iplist<Argument> &ilist_traits<Argument>::getList(Function *F) {
46 return F->getArgumentList();
49 // Explicit instantiations of SymbolTableListTraits since some of the methods
50 // are not in the public header file...
51 template class SymbolTableListTraits<Argument, Function>;
52 template class SymbolTableListTraits<BasicBlock, Function>;
54 //===----------------------------------------------------------------------===//
55 // Argument Implementation
56 //===----------------------------------------------------------------------===//
58 Argument::Argument(const Type *Ty, const std::string &Name, Function *Par)
59 : Value(Ty, Value::ArgumentVal) {
62 // Make sure that we get added to a function
63 LeakDetector::addGarbageObject(this);
66 Par->getArgumentList().push_back(this);
70 void Argument::setParent(Function *parent) {
72 LeakDetector::addGarbageObject(this);
75 LeakDetector::removeGarbageObject(this);
78 /// getArgNo - Return the index of this formal argument in its containing
79 /// function. For example in "void foo(int a, float b)" a is 0 and b is 1.
80 unsigned Argument::getArgNo() const {
81 const Function *F = getParent();
82 assert(F && "Argument is not in a function");
84 Function::const_arg_iterator AI = F->arg_begin();
86 for (; &*AI != this; ++AI)
92 /// hasByValAttr - Return true if this argument has the byval attribute on it
93 /// in its containing function.
94 bool Argument::hasByValAttr() const {
95 if (!isa<PointerType>(getType())) return false;
96 return getParent()->paramHasAttr(getArgNo()+1, ParamAttr::ByVal);
99 /// hasNoAliasAttr - Return true if this argument has the noalias attribute on
100 /// it in its containing function.
101 bool Argument::hasNoAliasAttr() const {
102 if (!isa<PointerType>(getType())) return false;
103 return getParent()->paramHasAttr(getArgNo()+1, ParamAttr::NoAlias);
106 /// hasSRetAttr - Return true if this argument has the sret attribute on
107 /// it in its containing function.
108 bool Argument::hasStructRetAttr() const {
109 if (!isa<PointerType>(getType())) return false;
110 if (this != getParent()->arg_begin()) return false; // StructRet param must be first param
111 return getParent()->paramHasAttr(1, ParamAttr::StructRet);
117 //===----------------------------------------------------------------------===//
118 // Helper Methods in Function
119 //===----------------------------------------------------------------------===//
121 const FunctionType *Function::getFunctionType() const {
122 return cast<FunctionType>(getType()->getElementType());
125 bool Function::isVarArg() const {
126 return getFunctionType()->isVarArg();
129 const Type *Function::getReturnType() const {
130 return getFunctionType()->getReturnType();
133 void Function::removeFromParent() {
134 getParent()->getFunctionList().remove(this);
137 void Function::eraseFromParent() {
138 getParent()->getFunctionList().erase(this);
141 /// @brief Determine whether the function has the given attribute.
142 bool Function::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
143 return ParamAttrs && ParamAttrs->paramHasAttr(i, attr);
146 /// @brief Extract the alignment for a call or parameter (0=unknown).
147 uint16_t Function::getParamAlignment(uint16_t i) const {
148 return ParamAttrs ? ParamAttrs->getParamAlignment(i) : 0;
151 /// @brief Determine if the function cannot return.
152 bool Function::doesNotReturn() const {
153 return paramHasAttr(0, ParamAttr::NoReturn);
156 /// @brief Determine if the function cannot unwind.
157 bool Function::doesNotThrow() const {
158 return paramHasAttr(0, ParamAttr::NoUnwind);
161 /// @brief Determine if the function does not access memory.
162 bool Function::doesNotAccessMemory() const {
163 return paramHasAttr(0, ParamAttr::ReadNone);
166 /// @brief Determine if the function does not access or only reads memory.
167 bool Function::onlyReadsMemory() const {
168 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly);
171 /// @brief Determine if the function returns a structure through first
172 /// pointer argument.
173 bool Function::hasStructRetAttr() const {
174 return paramHasAttr(1, ParamAttr::StructRet);
177 //===----------------------------------------------------------------------===//
178 // Function Implementation
179 //===----------------------------------------------------------------------===//
181 Function::Function(const FunctionType *Ty, LinkageTypes Linkage,
182 const std::string &name, Module *ParentModule)
183 : GlobalValue(PointerType::getUnqual(Ty),
184 Value::FunctionVal, 0, 0, Linkage, name),
186 SymTab = new ValueSymbolTable();
188 assert((getReturnType()->isFirstClassType() ||getReturnType() == Type::VoidTy
189 || isa<StructType>(getReturnType()))
190 && "LLVM functions cannot return aggregate values!");
192 // If the function has arguments, mark them as lazily built.
193 if (Ty->getNumParams())
194 SubclassData = 1; // Set the "has lazy arguments" bit.
196 // Make sure that we get added to a function
197 LeakDetector::addGarbageObject(this);
200 ParentModule->getFunctionList().push_back(this);
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 // Drop our reference to the parameter attributes, if any.
212 ParamAttrs->dropRef();
214 // Remove the function from the on-the-side collector table.
218 void Function::BuildLazyArguments() const {
219 // Create the arguments vector, all arguments start out unnamed.
220 const FunctionType *FT = getFunctionType();
221 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
222 assert(FT->getParamType(i) != Type::VoidTy &&
223 "Cannot have void typed arguments!");
224 ArgumentList.push_back(new Argument(FT->getParamType(i)));
227 // Clear the lazy arguments bit.
228 const_cast<Function*>(this)->SubclassData &= ~1;
231 size_t Function::arg_size() const {
232 return getFunctionType()->getNumParams();
234 bool Function::arg_empty() const {
235 return getFunctionType()->getNumParams() == 0;
238 void Function::setParent(Module *parent) {
240 LeakDetector::addGarbageObject(this);
243 LeakDetector::removeGarbageObject(this);
246 void Function::setParamAttrs(const ParamAttrsList *attrs) {
247 // Avoid deleting the ParamAttrsList if they are setting the
248 // attributes to the same list.
249 if (ParamAttrs == attrs)
252 // Drop reference on the old ParamAttrsList
254 ParamAttrs->dropRef();
256 // Add reference to the new ParamAttrsList
260 // Set the new ParamAttrsList.
264 // dropAllReferences() - This function causes all the subinstructions to "let
265 // go" of all references that they are maintaining. This allows one to
266 // 'delete' a whole class at a time, even though there may be circular
267 // references... first all references are dropped, and all use counts go to
268 // zero. Then everything is deleted for real. Note that no operations are
269 // valid on an object that has "dropped all references", except operator
272 void Function::dropAllReferences() {
273 for (iterator I = begin(), E = end(); I != E; ++I)
274 I->dropAllReferences();
275 BasicBlocks.clear(); // Delete all basic blocks...
278 // Maintain the collector name for each function in an on-the-side table. This
279 // saves allocating an additional word in Function for programs which do not use
280 // GC (i.e., most programs) at the cost of increased overhead for clients which
282 static DenseMap<const Function*,PooledStringPtr> *CollectorNames;
283 static StringPool *CollectorNamePool;
285 bool Function::hasCollector() const {
286 return CollectorNames && CollectorNames->count(this);
289 const char *Function::getCollector() const {
290 assert(hasCollector() && "Function has no collector");
291 return *(*CollectorNames)[this];
294 void Function::setCollector(const char *Str) {
295 if (!CollectorNamePool)
296 CollectorNamePool = new StringPool();
298 CollectorNames = new DenseMap<const Function*,PooledStringPtr>();
299 (*CollectorNames)[this] = CollectorNamePool->intern(Str);
302 void Function::clearCollector() {
303 if (CollectorNames) {
304 CollectorNames->erase(this);
305 if (CollectorNames->empty()) {
306 delete CollectorNames;
308 if (CollectorNamePool->empty()) {
309 delete CollectorNamePool;
310 CollectorNamePool = 0;
316 /// getIntrinsicID - This method returns the ID number of the specified
317 /// function, or Intrinsic::not_intrinsic if the function is not an
318 /// intrinsic, or if the pointer is null. This value is always defined to be
319 /// zero to allow easy checking for whether a function is intrinsic or not. The
320 /// particular intrinsic functions which correspond to this value are defined in
321 /// llvm/Intrinsics.h.
323 unsigned Function::getIntrinsicID(bool noAssert) const {
324 const ValueName *ValName = this->getValueName();
327 unsigned Len = ValName->getKeyLength();
328 const char *Name = ValName->getKeyData();
330 if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
331 || Name[2] != 'v' || Name[3] != 'm')
332 return 0; // All intrinsics start with 'llvm.'
334 assert((Len != 5 || noAssert) && "'llvm.' is an invalid intrinsic name!");
336 #define GET_FUNCTION_RECOGNIZER
337 #include "llvm/Intrinsics.gen"
338 #undef GET_FUNCTION_RECOGNIZER
339 assert(noAssert && "Invalid LLVM intrinsic name");
343 std::string Intrinsic::getName(ID id, const Type **Tys, unsigned numTys) {
344 assert(id < num_intrinsics && "Invalid intrinsic ID!");
345 const char * const Table[] = {
347 #define GET_INTRINSIC_NAME_TABLE
348 #include "llvm/Intrinsics.gen"
349 #undef GET_INTRINSIC_NAME_TABLE
353 std::string Result(Table[id]);
354 for (unsigned i = 0; i < numTys; ++i)
356 Result += "." + MVT::getValueTypeString(MVT::getValueType(Tys[i]));
360 const FunctionType *Intrinsic::getType(ID id, const Type **Tys,
362 const Type *ResultTy = NULL;
363 std::vector<const Type*> ArgTys;
364 bool IsVarArg = false;
366 #define GET_INTRINSIC_GENERATOR
367 #include "llvm/Intrinsics.gen"
368 #undef GET_INTRINSIC_GENERATOR
370 return FunctionType::get(ResultTy, ArgTys, IsVarArg);
373 const ParamAttrsList *Intrinsic::getParamAttrs(ID id) {
374 ParamAttrsVector Attrs;
375 ParameterAttributes Attr = ParamAttr::None;
377 #define GET_INTRINSIC_ATTRIBUTES
378 #include "llvm/Intrinsics.gen"
379 #undef GET_INTRINSIC_ATTRIBUTES
381 // Intrinsics cannot throw exceptions.
382 Attr |= ParamAttr::NoUnwind;
384 Attrs.push_back(ParamAttrsWithIndex::get(0, Attr));
385 return ParamAttrsList::get(Attrs);
388 Function *Intrinsic::getDeclaration(Module *M, ID id, const Type **Tys,
390 // There can never be multiple globals with the same name of different types,
391 // because intrinsics must be a specific type.
393 cast<Function>(M->getOrInsertFunction(getName(id, Tys, numTys),
394 getType(id, Tys, numTys)));
395 F->setParamAttrs(getParamAttrs(id));
399 Value *IntrinsicInst::StripPointerCasts(Value *Ptr) {
400 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
401 if (CE->getOpcode() == Instruction::BitCast) {
402 if (isa<PointerType>(CE->getOperand(0)->getType()))
403 return StripPointerCasts(CE->getOperand(0));
404 } else if (CE->getOpcode() == Instruction::GetElementPtr) {
405 for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
406 if (!CE->getOperand(i)->isNullValue())
408 return StripPointerCasts(CE->getOperand(0));
413 if (BitCastInst *CI = dyn_cast<BitCastInst>(Ptr)) {
414 if (isa<PointerType>(CI->getOperand(0)->getType()))
415 return StripPointerCasts(CI->getOperand(0));
416 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
417 if (GEP->hasAllZeroIndices())
418 return StripPointerCasts(GEP->getOperand(0));