lib/VMCore/Function.cpp

   1 //===-- Function.cpp - Implement the Global object classes ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by the LLVM research group and is distributed under
   6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the Function class for the VMCore library.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Module.h"
  15 #include "llvm/DerivedTypes.h"
  16 #include "llvm/ParameterAttributes.h"
  17 #include "llvm/IntrinsicInst.h"
  18 #include "llvm/CodeGen/ValueTypes.h"
  19 #include "llvm/Support/LeakDetector.h"
  20 #include "llvm/Support/ManagedStatic.h"
  21 #include "SymbolTableListTraitsImpl.h"
  22 #include "llvm/ADT/StringExtras.h"
  23 using namespace llvm;
  24
  25 BasicBlock *ilist_traits<BasicBlock>::createSentinel() {
  26   BasicBlock *Ret = new BasicBlock();
  27   // This should not be garbage monitored.
  28   LeakDetector::removeGarbageObject(Ret);
  29   return Ret;
  30 }
  31
  32 iplist<BasicBlock> &ilist_traits<BasicBlock>::getList(Function *F) {
  33   return F->getBasicBlockList();
  34 }
  35
  36 Argument *ilist_traits<Argument>::createSentinel() {
  37   Argument *Ret = new Argument(Type::Int32Ty);
  38   // This should not be garbage monitored.
  39   LeakDetector::removeGarbageObject(Ret);
  40   return Ret;
  41 }
  42
  43 iplist<Argument> &ilist_traits<Argument>::getList(Function *F) {
  44   return F->getArgumentList();
  45 }
  46
  47 // Explicit instantiations of SymbolTableListTraits since some of the methods
  48 // are not in the public header file...
  49 template class SymbolTableListTraits<Argument, Function>;
  50 template class SymbolTableListTraits<BasicBlock, Function>;
  51
  52 //===----------------------------------------------------------------------===//
  53 // Argument Implementation
  54 //===----------------------------------------------------------------------===//
  55
  56 Argument::Argument(const Type *Ty, const std::string &Name, Function *Par)
  57   : Value(Ty, Value::ArgumentVal) {
  58   Parent = 0;
  59
  60   // Make sure that we get added to a function
  61   LeakDetector::addGarbageObject(this);
  62
  63   if (Par)
  64     Par->getArgumentList().push_back(this);
  65   setName(Name);
  66 }
  67
  68 void Argument::setParent(Function *parent) {
  69   if (getParent())
  70     LeakDetector::addGarbageObject(this);
  71   Parent = parent;
  72   if (getParent())
  73     LeakDetector::removeGarbageObject(this);
  74 }
  75
  76 //===----------------------------------------------------------------------===//
  77 // ParamAttrsList Implementation
  78 //===----------------------------------------------------------------------===//
  79
  80 uint16_t
  81 ParamAttrsList::getParamAttrs(uint16_t Index) const {
  82   unsigned limit = attrs.size();
  83   for (unsigned i = 0; i < limit; ++i)
  84     if (attrs[i].index == Index)
  85       return attrs[i].attrs;
  86   return ParamAttr::None;
  87 }
  88
  89
  90 std::string
  91 ParamAttrsList::getParamAttrsText(uint16_t Attrs) {
  92   std::string Result;
  93   if (Attrs & ParamAttr::ZExt)
  94     Result += "zeroext ";
  95   if (Attrs & ParamAttr::SExt)
  96     Result += "signext ";
  97   if (Attrs & ParamAttr::NoReturn)
  98     Result += "noreturn ";
  99   if (Attrs & ParamAttr::NoUnwind)
 100     Result += "nounwind ";
 101   if (Attrs & ParamAttr::InReg)
 102     Result += "inreg ";
 103   if (Attrs & ParamAttr::NoAlias)
 104     Result += "noalias ";
 105   if (Attrs & ParamAttr::StructRet)
 106     Result += "sret ";
 107   if (Attrs & ParamAttr::ByVal)
 108     Result += "byval ";
 109   if (Attrs & ParamAttr::Nest)
 110     Result += "nest ";
 111   return Result;
 112 }
 113
 114 void
 115 ParamAttrsList::Profile(FoldingSetNodeID &ID) const {
 116   for (unsigned i = 0; i < attrs.size(); ++i) {
 117     unsigned val = attrs[i].attrs << 16 | attrs[i].index;
 118     ID.AddInteger(val);
 119   }
 120 }
 121
 122 static ManagedStatic<FoldingSet<ParamAttrsList> > ParamAttrsLists;
 123
 124 ParamAttrsList *
 125 ParamAttrsList::get(const ParamAttrsVector &attrVec) {
 126   assert(!attrVec.empty() && "Illegal to create empty ParamAttrsList");
 127 #ifndef NDEBUG
 128   for (unsigned i = 1, e = attrVec.size(); i < e; ++i)
 129     assert(attrVec[i-1].index < attrVec[i].index && "Misordered ParamAttrsList!");
 130 #endif
 131   ParamAttrsList key(attrVec);
 132   FoldingSetNodeID ID;
 133   key.Profile(ID);
 134   void *InsertPos;
 135   ParamAttrsList* PAL = ParamAttrsLists->FindNodeOrInsertPos(ID, InsertPos);
 136   if (!PAL) {
 137     PAL = new ParamAttrsList(attrVec);
 138     ParamAttrsLists->InsertNode(PAL, InsertPos);
 139   }
 140   return PAL;
 141 }
 142
 143 ParamAttrsList::~ParamAttrsList() {
 144   ParamAttrsLists->RemoveNode(this);
 145 }
 146
 147 //===----------------------------------------------------------------------===//
 148 // Function Implementation
 149 //===----------------------------------------------------------------------===//
 150
 151 Function::Function(const FunctionType *Ty, LinkageTypes Linkage,
 152                    const std::string &name, Module *ParentModule)
 153   : GlobalValue(PointerType::get(Ty), Value::FunctionVal, 0, 0, Linkage, name) {
 154   ParamAttrs = 0;
 155   SymTab = new ValueSymbolTable();
 156
 157   assert((getReturnType()->isFirstClassType() ||getReturnType() == Type::VoidTy)
 158          && "LLVM functions cannot return aggregate values!");
 159
 160   // If the function has arguments, mark them as lazily built.
 161   if (Ty->getNumParams())
 162     SubclassData = 1;   // Set the "has lazy arguments" bit.
 163
 164   // Make sure that we get added to a function
 165   LeakDetector::addGarbageObject(this);
 166
 167   if (ParentModule)
 168     ParentModule->getFunctionList().push_back(this);
 169 }
 170
 171 Function::~Function() {
 172   dropAllReferences();    // After this it is safe to delete instructions.
 173
 174   // Delete all of the method arguments and unlink from symbol table...
 175   ArgumentList.clear();
 176   delete SymTab;
 177
 178   // Drop our reference to the parameter attributes, if any.
 179   if (ParamAttrs)
 180     ParamAttrs->dropRef();
 181 }
 182
 183 void Function::BuildLazyArguments() const {
 184   // Create the arguments vector, all arguments start out unnamed.
 185   const FunctionType *FT = getFunctionType();
 186   for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
 187     assert(FT->getParamType(i) != Type::VoidTy &&
 188            "Cannot have void typed arguments!");
 189     ArgumentList.push_back(new Argument(FT->getParamType(i)));
 190   }
 191
 192   // Clear the lazy arguments bit.
 193   const_cast<Function*>(this)->SubclassData &= ~1;
 194 }
 195
 196 size_t Function::arg_size() const {
 197   return getFunctionType()->getNumParams();
 198 }
 199 bool Function::arg_empty() const {
 200   return getFunctionType()->getNumParams() == 0;
 201 }
 202
 203 void Function::setParent(Module *parent) {
 204   if (getParent())
 205     LeakDetector::addGarbageObject(this);
 206   Parent = parent;
 207   if (getParent())
 208     LeakDetector::removeGarbageObject(this);
 209 }
 210
 211 void Function::setParamAttrs(ParamAttrsList *attrs) {
 212   if (ParamAttrs)
 213     ParamAttrs->dropRef();
 214
 215   if (attrs)
 216     attrs->addRef();
 217
 218   ParamAttrs = attrs;
 219 }
 220
 221 const FunctionType *Function::getFunctionType() const {
 222   return cast<FunctionType>(getType()->getElementType());
 223 }
 224
 225 bool Function::isVarArg() const {
 226   return getFunctionType()->isVarArg();
 227 }
 228
 229 const Type *Function::getReturnType() const {
 230   return getFunctionType()->getReturnType();
 231 }
 232
 233 void Function::removeFromParent() {
 234   getParent()->getFunctionList().remove(this);
 235 }
 236
 237 void Function::eraseFromParent() {
 238   getParent()->getFunctionList().erase(this);
 239 }
 240
 241 // dropAllReferences() - This function causes all the subinstructions to "let
 242 // go" of all references that they are maintaining.  This allows one to
 243 // 'delete' a whole class at a time, even though there may be circular
 244 // references... first all references are dropped, and all use counts go to
 245 // zero.  Then everything is deleted for real.  Note that no operations are
 246 // valid on an object that has "dropped all references", except operator
 247 // delete.
 248 //
 249 void Function::dropAllReferences() {
 250   for (iterator I = begin(), E = end(); I != E; ++I)
 251     I->dropAllReferences();
 252   BasicBlocks.clear();    // Delete all basic blocks...
 253 }
 254
 255 /// getIntrinsicID - This method returns the ID number of the specified
 256 /// function, or Intrinsic::not_intrinsic if the function is not an
 257 /// intrinsic, or if the pointer is null.  This value is always defined to be
 258 /// zero to allow easy checking for whether a function is intrinsic or not.  The
 259 /// particular intrinsic functions which correspond to this value are defined in
 260 /// llvm/Intrinsics.h.
 261 ///
 262 unsigned Function::getIntrinsicID(bool noAssert) const {
 263   const ValueName *ValName = this->getValueName();
 264   if (!ValName)
 265     return 0;
 266   unsigned Len = ValName->getKeyLength();
 267   const char *Name = ValName->getKeyData();
 268
 269   if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
 270       || Name[2] != 'v' || Name[3] != 'm')
 271     return 0;  // All intrinsics start with 'llvm.'
 272
 273   assert((Len != 5 || noAssert) && "'llvm.' is an invalid intrinsic name!");
 274
 275 #define GET_FUNCTION_RECOGNIZER
 276 #include "llvm/Intrinsics.gen"
 277 #undef GET_FUNCTION_RECOGNIZER
 278   assert(noAssert && "Invalid LLVM intrinsic name");
 279   return 0;
 280 }
 281
 282 std::string Intrinsic::getName(ID id, const Type **Tys, unsigned numTys) {
 283   assert(id < num_intrinsics && "Invalid intrinsic ID!");
 284   const char * const Table[] = {
 285     "not_intrinsic",
 286 #define GET_INTRINSIC_NAME_TABLE
 287 #include "llvm/Intrinsics.gen"
 288 #undef GET_INTRINSIC_NAME_TABLE
 289   };
 290   if (numTys == 0)
 291     return Table[id];
 292   std::string Result(Table[id]);
 293   for (unsigned i = 0; i < numTys; ++i)
 294     if (Tys[i])
 295       Result += "." + MVT::getValueTypeString(MVT::getValueType(Tys[i]));
 296   return Result;
 297 }
 298
 299 const FunctionType *Intrinsic::getType(ID id, const Type **Tys,
 300                                        unsigned numTys) {
 301   const Type *ResultTy = NULL;
 302   std::vector<const Type*> ArgTys;
 303   bool IsVarArg = false;
 304
 305 #define GET_INTRINSIC_GENERATOR
 306 #include "llvm/Intrinsics.gen"
 307 #undef GET_INTRINSIC_GENERATOR
 308
 309   return FunctionType::get(ResultTy, ArgTys, IsVarArg);
 310 }
 311
 312 Function *Intrinsic::getDeclaration(Module *M, ID id, const Type **Tys,
 313                                     unsigned numTys) {
 314 // There can never be multiple globals with the same name of different types,
 315 // because intrinsics must be a specific type.
 316   return cast<Function>(M->getOrInsertFunction(getName(id, Tys, numTys),
 317                                                getType(id, Tys, numTys)));
 318 }
 319
 320 Value *IntrinsicInst::StripPointerCasts(Value *Ptr) {
 321   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
 322     if (CE->getOpcode() == Instruction::BitCast) {
 323       if (isa<PointerType>(CE->getOperand(0)->getType()))
 324         return StripPointerCasts(CE->getOperand(0));
 325     } else if (CE->getOpcode() == Instruction::GetElementPtr) {
 326       for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
 327         if (!CE->getOperand(i)->isNullValue())
 328           return Ptr;
 329       return StripPointerCasts(CE->getOperand(0));
 330     }
 331     return Ptr;
 332   }
 333
 334   if (BitCastInst *CI = dyn_cast<BitCastInst>(Ptr)) {
 335     if (isa<PointerType>(CI->getOperand(0)->getType()))
 336       return StripPointerCasts(CI->getOperand(0));
 337   } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
 338     if (GEP->hasAllZeroIndices())
 339       return StripPointerCasts(GEP->getOperand(0));
 340   }
 341   return Ptr;
 342 }
 343
 344 // vim: sw=2 ai