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/CodeGen/ValueTypes.h"
18 #include "llvm/Support/LeakDetector.h"
19 #include "llvm/Support/StringPool.h"
20 #include "SymbolTableListTraitsImpl.h"
21 #include "llvm/ADT/BitVector.h"
22 #include "llvm/ADT/DenseMap.h"
23 #include "llvm/ADT/StringExtras.h"
26 BasicBlock *ilist_traits<BasicBlock>::createSentinel() {
27 BasicBlock *Ret = new BasicBlock();
28 // This should not be garbage monitored.
29 LeakDetector::removeGarbageObject(Ret);
33 iplist<BasicBlock> &ilist_traits<BasicBlock>::getList(Function *F) {
34 return F->getBasicBlockList();
37 Argument *ilist_traits<Argument>::createSentinel() {
38 Argument *Ret = new Argument(Type::Int32Ty);
39 // This should not be garbage monitored.
40 LeakDetector::removeGarbageObject(Ret);
44 iplist<Argument> &ilist_traits<Argument>::getList(Function *F) {
45 return F->getArgumentList();
48 // Explicit instantiations of SymbolTableListTraits since some of the methods
49 // are not in the public header file...
50 template class SymbolTableListTraits<Argument, Function>;
51 template class SymbolTableListTraits<BasicBlock, Function>;
53 //===----------------------------------------------------------------------===//
54 // Argument Implementation
55 //===----------------------------------------------------------------------===//
57 Argument::Argument(const Type *Ty, const std::string &Name, Function *Par)
58 : Value(Ty, Value::ArgumentVal) {
61 // Make sure that we get added to a function
62 LeakDetector::addGarbageObject(this);
65 Par->getArgumentList().push_back(this);
69 void Argument::setParent(Function *parent) {
71 LeakDetector::addGarbageObject(this);
74 LeakDetector::removeGarbageObject(this);
77 /// getArgNo - Return the index of this formal argument in its containing
78 /// function. For example in "void foo(int a, float b)" a is 0 and b is 1.
79 unsigned Argument::getArgNo() const {
80 const Function *F = getParent();
81 assert(F && "Argument is not in a function");
83 Function::const_arg_iterator AI = F->arg_begin();
85 for (; &*AI != this; ++AI)
91 /// hasByValAttr - Return true if this argument has the byval attribute on it
92 /// in its containing function.
93 bool Argument::hasByValAttr() const {
94 if (!isa<PointerType>(getType())) return false;
95 return getParent()->paramHasAttr(getArgNo()+1, ParamAttr::ByVal);
98 /// hasNoAliasAttr - Return true if this argument has the noalias attribute on
99 /// it in its containing function.
100 bool Argument::hasNoAliasAttr() const {
101 if (!isa<PointerType>(getType())) return false;
102 return getParent()->paramHasAttr(getArgNo()+1, ParamAttr::NoAlias);
105 /// hasSRetAttr - Return true if this argument has the sret attribute on
106 /// it in its containing function.
107 bool Argument::hasStructRetAttr() const {
108 if (!isa<PointerType>(getType())) return false;
109 if (this != getParent()->arg_begin()) return false; // StructRet param must be first param
110 return getParent()->paramHasAttr(1, ParamAttr::StructRet);
116 //===----------------------------------------------------------------------===//
117 // Helper Methods in Function
118 //===----------------------------------------------------------------------===//
120 const FunctionType *Function::getFunctionType() const {
121 return cast<FunctionType>(getType()->getElementType());
124 bool Function::isVarArg() const {
125 return getFunctionType()->isVarArg();
128 const Type *Function::getReturnType() const {
129 return getFunctionType()->getReturnType();
132 void Function::removeFromParent() {
133 getParent()->getFunctionList().remove(this);
136 void Function::eraseFromParent() {
137 getParent()->getFunctionList().erase(this);
140 /// @brief Determine whether the function has the given attribute.
141 bool Function::paramHasAttr(uint16_t i, ParameterAttributes attr) const {
142 return ParamAttrs.paramHasAttr(i, attr);
145 /// @brief Extract the alignment for a call or parameter (0=unknown).
146 uint16_t Function::getParamAlignment(uint16_t i) const {
147 return ParamAttrs.getParamAlignment(i);
150 /// @brief Determine if the function cannot return.
151 bool Function::doesNotReturn() const {
152 return paramHasAttr(0, ParamAttr::NoReturn);
155 /// @brief Determine if the function cannot unwind.
156 bool Function::doesNotThrow() const {
157 return paramHasAttr(0, ParamAttr::NoUnwind);
160 /// @brief Determine if the function does not access memory.
161 bool Function::doesNotAccessMemory() const {
162 return paramHasAttr(0, ParamAttr::ReadNone);
165 /// @brief Determine if the function does not access or only reads memory.
166 bool Function::onlyReadsMemory() const {
167 return doesNotAccessMemory() || paramHasAttr(0, ParamAttr::ReadOnly);
170 /// @brief Determine if the function returns a structure through first
171 /// pointer argument.
172 bool Function::hasStructRetAttr() const {
173 return paramHasAttr(1, ParamAttr::StructRet);
176 //===----------------------------------------------------------------------===//
177 // Function Implementation
178 //===----------------------------------------------------------------------===//
180 Function::Function(const FunctionType *Ty, LinkageTypes Linkage,
181 const std::string &name, Module *ParentModule)
182 : GlobalValue(PointerType::getUnqual(Ty),
183 Value::FunctionVal, 0, 0, Linkage, name) {
184 SymTab = new ValueSymbolTable();
186 assert((getReturnType()->isFirstClassType() ||getReturnType() == Type::VoidTy
187 || isa<StructType>(getReturnType()))
188 && "LLVM functions cannot return aggregate values!");
190 // If the function has arguments, mark them as lazily built.
191 if (Ty->getNumParams())
192 SubclassData = 1; // Set the "has lazy arguments" bit.
194 // Make sure that we get added to a function
195 LeakDetector::addGarbageObject(this);
198 ParentModule->getFunctionList().push_back(this);
201 Function::~Function() {
202 dropAllReferences(); // After this it is safe to delete instructions.
204 // Delete all of the method arguments and unlink from symbol table...
205 ArgumentList.clear();
208 // Remove the function from the on-the-side collector table.
212 void Function::BuildLazyArguments() const {
213 // Create the arguments vector, all arguments start out unnamed.
214 const FunctionType *FT = getFunctionType();
215 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
216 assert(FT->getParamType(i) != Type::VoidTy &&
217 "Cannot have void typed arguments!");
218 ArgumentList.push_back(new Argument(FT->getParamType(i)));
221 // Clear the lazy arguments bit.
222 const_cast<Function*>(this)->SubclassData &= ~1;
225 size_t Function::arg_size() const {
226 return getFunctionType()->getNumParams();
228 bool Function::arg_empty() const {
229 return getFunctionType()->getNumParams() == 0;
232 void Function::setParent(Module *parent) {
234 LeakDetector::addGarbageObject(this);
237 LeakDetector::removeGarbageObject(this);
240 // dropAllReferences() - This function causes all the subinstructions to "let
241 // go" of all references that they are maintaining. This allows one to
242 // 'delete' a whole class at a time, even though there may be circular
243 // references... first all references are dropped, and all use counts go to
244 // zero. Then everything is deleted for real. Note that no operations are
245 // valid on an object that has "dropped all references", except operator
248 void Function::dropAllReferences() {
249 for (iterator I = begin(), E = end(); I != E; ++I)
250 I->dropAllReferences();
251 BasicBlocks.clear(); // Delete all basic blocks...
254 // Maintain the collector name for each function in an on-the-side table. This
255 // saves allocating an additional word in Function for programs which do not use
256 // GC (i.e., most programs) at the cost of increased overhead for clients which
258 static DenseMap<const Function*,PooledStringPtr> *CollectorNames;
259 static StringPool *CollectorNamePool;
261 bool Function::hasCollector() const {
262 return CollectorNames && CollectorNames->count(this);
265 const char *Function::getCollector() const {
266 assert(hasCollector() && "Function has no collector");
267 return *(*CollectorNames)[this];
270 void Function::setCollector(const char *Str) {
271 if (!CollectorNamePool)
272 CollectorNamePool = new StringPool();
274 CollectorNames = new DenseMap<const Function*,PooledStringPtr>();
275 (*CollectorNames)[this] = CollectorNamePool->intern(Str);
278 void Function::clearCollector() {
279 if (CollectorNames) {
280 CollectorNames->erase(this);
281 if (CollectorNames->empty()) {
282 delete CollectorNames;
284 if (CollectorNamePool->empty()) {
285 delete CollectorNamePool;
286 CollectorNamePool = 0;
292 /// getIntrinsicID - This method returns the ID number of the specified
293 /// function, or Intrinsic::not_intrinsic if the function is not an
294 /// intrinsic, or if the pointer is null. This value is always defined to be
295 /// zero to allow easy checking for whether a function is intrinsic or not. The
296 /// particular intrinsic functions which correspond to this value are defined in
297 /// llvm/Intrinsics.h.
299 unsigned Function::getIntrinsicID(bool noAssert) const {
300 const ValueName *ValName = this->getValueName();
303 unsigned Len = ValName->getKeyLength();
304 const char *Name = ValName->getKeyData();
306 if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
307 || Name[2] != 'v' || Name[3] != 'm')
308 return 0; // All intrinsics start with 'llvm.'
310 assert((Len != 5 || noAssert) && "'llvm.' is an invalid intrinsic name!");
312 #define GET_FUNCTION_RECOGNIZER
313 #include "llvm/Intrinsics.gen"
314 #undef GET_FUNCTION_RECOGNIZER
315 assert(noAssert && "Invalid LLVM intrinsic name");
319 std::string Intrinsic::getName(ID id, const Type **Tys, unsigned numTys) {
320 assert(id < num_intrinsics && "Invalid intrinsic ID!");
321 const char * const Table[] = {
323 #define GET_INTRINSIC_NAME_TABLE
324 #include "llvm/Intrinsics.gen"
325 #undef GET_INTRINSIC_NAME_TABLE
329 std::string Result(Table[id]);
330 for (unsigned i = 0; i < numTys; ++i)
332 Result += "." + MVT::getValueTypeString(MVT::getValueType(Tys[i]));
336 const FunctionType *Intrinsic::getType(ID id, const Type **Tys,
338 const Type *ResultTy = NULL;
339 std::vector<const Type*> ArgTys;
340 bool IsVarArg = false;
342 #define GET_INTRINSIC_GENERATOR
343 #include "llvm/Intrinsics.gen"
344 #undef GET_INTRINSIC_GENERATOR
346 return FunctionType::get(ResultTy, ArgTys, IsVarArg);
349 PAListPtr Intrinsic::getParamAttrs(ID id) {
350 ParameterAttributes Attr = ParamAttr::None;
352 #define GET_INTRINSIC_ATTRIBUTES
353 #include "llvm/Intrinsics.gen"
354 #undef GET_INTRINSIC_ATTRIBUTES
356 // Intrinsics cannot throw exceptions.
357 Attr |= ParamAttr::NoUnwind;
359 ParamAttrsWithIndex PAWI = ParamAttrsWithIndex::get(0, Attr);
360 return PAListPtr::get(&PAWI, 1);
363 Function *Intrinsic::getDeclaration(Module *M, ID id, const Type **Tys,
365 // There can never be multiple globals with the same name of different types,
366 // because intrinsics must be a specific type.
368 cast<Function>(M->getOrInsertFunction(getName(id, Tys, numTys),
369 getType(id, Tys, numTys)));
370 F->setParamAttrs(getParamAttrs(id));
374 Value *IntrinsicInst::StripPointerCasts(Value *Ptr) {
375 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
376 if (CE->getOpcode() == Instruction::BitCast) {
377 if (isa<PointerType>(CE->getOperand(0)->getType()))
378 return StripPointerCasts(CE->getOperand(0));
379 } else if (CE->getOpcode() == Instruction::GetElementPtr) {
380 for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
381 if (!CE->getOperand(i)->isNullValue())
383 return StripPointerCasts(CE->getOperand(0));
388 if (BitCastInst *CI = dyn_cast<BitCastInst>(Ptr)) {
389 if (isa<PointerType>(CI->getOperand(0)->getType()))
390 return StripPointerCasts(CI->getOperand(0));
391 } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
392 if (GEP->hasAllZeroIndices())
393 return StripPointerCasts(GEP->getOperand(0));