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 & GlobalVariable classes for the VMCore
  11 // library.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Module.h"
  16 #include "llvm/DerivedTypes.h"
  17 #include "llvm/IntrinsicInst.h"
  18 #include "llvm/Support/LeakDetector.h"
  19 #include "SymbolTableListTraitsImpl.h"
  20 #include "llvm/ADT/StringExtras.h"
  21 using namespace llvm;
  22
  23 BasicBlock *ilist_traits<BasicBlock>::createSentinel() {
  24   BasicBlock *Ret = new BasicBlock();
  25   // This should not be garbage monitored.
  26   LeakDetector::removeGarbageObject(Ret);
  27   return Ret;
  28 }
  29
  30 iplist<BasicBlock> &ilist_traits<BasicBlock>::getList(Function *F) {
  31   return F->getBasicBlockList();
  32 }
  33
  34 Argument *ilist_traits<Argument>::createSentinel() {
  35   Argument *Ret = new Argument(Type::IntTy);
  36   // This should not be garbage monitored.
  37   LeakDetector::removeGarbageObject(Ret);
  38   return Ret;
  39 }
  40
  41 iplist<Argument> &ilist_traits<Argument>::getList(Function *F) {
  42   return F->getArgumentList();
  43 }
  44
  45 // Explicit instantiations of SymbolTableListTraits since some of the methods
  46 // are not in the public header file...
  47 template class SymbolTableListTraits<Argument, Function, Function>;
  48 template class SymbolTableListTraits<BasicBlock, Function, Function>;
  49
  50 //===----------------------------------------------------------------------===//
  51 // Argument Implementation
  52 //===----------------------------------------------------------------------===//
  53
  54 Argument::Argument(const Type *Ty, const std::string &Name, Function *Par)
  55   : Value(Ty, Value::ArgumentVal, Name) {
  56   Parent = 0;
  57
  58   // Make sure that we get added to a function
  59   LeakDetector::addGarbageObject(this);
  60
  61   if (Par)
  62     Par->getArgumentList().push_back(this);
  63 }
  64
  65 void Argument::setParent(Function *parent) {
  66   if (getParent())
  67     LeakDetector::addGarbageObject(this);
  68   Parent = parent;
  69   if (getParent())
  70     LeakDetector::removeGarbageObject(this);
  71 }
  72
  73 //===----------------------------------------------------------------------===//
  74 // Function Implementation
  75 //===----------------------------------------------------------------------===//
  76
  77 Function::Function(const FunctionType *Ty, LinkageTypes Linkage,
  78                    const std::string &name, Module *ParentModule)
  79   : GlobalValue(PointerType::get(Ty), Value::FunctionVal, 0, 0, Linkage, name) {
  80   CallingConvention = 0;
  81   BasicBlocks.setItemParent(this);
  82   BasicBlocks.setParent(this);
  83   ArgumentList.setItemParent(this);
  84   ArgumentList.setParent(this);
  85   SymTab = new SymbolTable();
  86
  87   assert((getReturnType()->isFirstClassType() ||getReturnType() == Type::VoidTy)
  88          && "LLVM functions cannot return aggregate values!");
  89
  90   // Create the arguments vector, all arguments start out unnamed.
  91   for (unsigned i = 0, e = Ty->getNumParams(); i != e; ++i) {
  92     assert(Ty->getParamType(i) != Type::VoidTy &&
  93            "Cannot have void typed arguments!");
  94     ArgumentList.push_back(new Argument(Ty->getParamType(i)));
  95   }
  96
  97   // Make sure that we get added to a function
  98   LeakDetector::addGarbageObject(this);
  99
 100   if (ParentModule)
 101     ParentModule->getFunctionList().push_back(this);
 102 }
 103
 104 Function::~Function() {
 105   dropAllReferences();    // After this it is safe to delete instructions.
 106
 107   // Delete all of the method arguments and unlink from symbol table...
 108   ArgumentList.clear();
 109   ArgumentList.setParent(0);
 110   delete SymTab;
 111 }
 112
 113 void Function::setParent(Module *parent) {
 114   if (getParent())
 115     LeakDetector::addGarbageObject(this);
 116   Parent = parent;
 117   if (getParent())
 118     LeakDetector::removeGarbageObject(this);
 119 }
 120
 121 const FunctionType *Function::getFunctionType() const {
 122   return cast<FunctionType>(getType()->getElementType());
 123 }
 124
 125 bool Function::isVarArg() const {
 126   return getFunctionType()->isVarArg();
 127 }
 128
 129 const Type *Function::getReturnType() const {
 130   return getFunctionType()->getReturnType();
 131 }
 132
 133 void Function::removeFromParent() {
 134   getParent()->getFunctionList().remove(this);
 135 }
 136
 137 void Function::eraseFromParent() {
 138   getParent()->getFunctionList().erase(this);
 139 }
 140
 141
 142 /// renameLocalSymbols - This method goes through the Function's symbol table
 143 /// and renames any symbols that conflict with symbols at global scope.  This is
 144 /// required before printing out to a textual form, to ensure that there is no
 145 /// ambiguity when parsing.
 146 void Function::renameLocalSymbols() {
 147   SymbolTable &LST = getSymbolTable();                 // Local Symtab
 148   SymbolTable &GST = getParent()->getSymbolTable();    // Global Symtab
 149
 150   for (SymbolTable::plane_iterator LPI = LST.plane_begin(), E = LST.plane_end();
 151        LPI != E; ++LPI)
 152     // All global symbols are of pointer type, ignore any non-pointer planes.
 153     if (const PointerType *CurTy = dyn_cast<PointerType>(LPI->first)) {
 154       // Only check if the global plane has any symbols of this type.
 155       SymbolTable::plane_iterator GPI = GST.find(LPI->first);
 156       if (GPI != GST.plane_end()) {
 157         SymbolTable::ValueMap &LVM       = LPI->second;
 158         const SymbolTable::ValueMap &GVM = GPI->second;
 159
 160         // Loop over all local symbols, renaming those that are in the global
 161         // symbol table already.
 162         for (SymbolTable::value_iterator VI = LVM.begin(), E = LVM.end();
 163              VI != E;) {
 164           Value *V                = VI->second;
 165           const std::string &Name = VI->first;
 166           ++VI;
 167           if (GVM.count(Name)) {
 168             static unsigned UniqueNum = 0;
 169             // Find a name that does not conflict!
 170             while (GVM.count(Name + "_" + utostr(++UniqueNum)) ||
 171                    LVM.count(Name + "_" + utostr(UniqueNum)))
 172               /* scan for UniqueNum that works */;
 173             V->setName(Name + "_" + utostr(UniqueNum));
 174           }
 175         }
 176       }
 177     }
 178 }
 179
 180
 181 // dropAllReferences() - This function causes all the subinstructions to "let
 182 // go" of all references that they are maintaining.  This allows one to
 183 // 'delete' a whole class at a time, even though there may be circular
 184 // references... first all references are dropped, and all use counts go to
 185 // zero.  Then everything is deleted for real.  Note that no operations are
 186 // valid on an object that has "dropped all references", except operator
 187 // delete.
 188 //
 189 void Function::dropAllReferences() {
 190   for (iterator I = begin(), E = end(); I != E; ++I)
 191     I->dropAllReferences();
 192   BasicBlocks.clear();    // Delete all basic blocks...
 193 }
 194
 195 /// getIntrinsicID - This method returns the ID number of the specified
 196 /// function, or Intrinsic::not_intrinsic if the function is not an
 197 /// intrinsic, or if the pointer is null.  This value is always defined to be
 198 /// zero to allow easy checking for whether a function is intrinsic or not.  The
 199 /// particular intrinsic functions which correspond to this value are defined in
 200 /// llvm/Intrinsics.h.
 201 ///
 202 unsigned Function::getIntrinsicID() const {
 203   const std::string& Name = this->getName();
 204   if (Name.size() < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
 205       || Name[2] != 'v' || Name[3] != 'm')
 206     return 0;  // All intrinsics start with 'llvm.'
 207
 208   assert(Name.size() != 5 && "'llvm.' is an invalid intrinsic name!");
 209
 210 #define GET_FUNCTION_RECOGNIZER
 211 #include "llvm/Intrinsics.gen"
 212 #undef GET_FUNCTION_RECOGNIZER
 213   return 0;
 214 }
 215
 216 const char *Intrinsic::getName(ID id) {
 217   assert(id < num_intrinsics && "Invalid intrinsic ID!");
 218   const char * const Table[] = {
 219     "not_intrinsic",
 220 #define GET_INTRINSIC_NAME_TABLE
 221 #include "llvm/Intrinsics.gen"
 222 #undef GET_INTRINSIC_NAME_TABLE
 223   };
 224   return Table[id];
 225 }
 226
 227 Value *IntrinsicInst::StripPointerCasts(Value *Ptr) {
 228   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
 229     if (CE->getOpcode() == Instruction::Cast) {
 230       if (isa<PointerType>(CE->getOperand(0)->getType()))
 231         return StripPointerCasts(CE->getOperand(0));
 232     } else if (CE->getOpcode() == Instruction::GetElementPtr) {
 233       for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i)
 234         if (!CE->getOperand(i)->isNullValue())
 235           return Ptr;
 236       return StripPointerCasts(CE->getOperand(0));
 237     }
 238     return Ptr;
 239   }
 240
 241   if (CastInst *CI = dyn_cast<CastInst>(Ptr)) {
 242     if (isa<PointerType>(CI->getOperand(0)->getType()))
 243       return StripPointerCasts(CI->getOperand(0));
 244   } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr)) {
 245     for (unsigned i = 1, e = GEP->getNumOperands(); i != e; ++i)
 246       if (!isa<Constant>(GEP->getOperand(i)) ||
 247           !cast<Constant>(GEP->getOperand(i))->isNullValue())
 248         return Ptr;
 249     return StripPointerCasts(GEP->getOperand(0));
 250   }
 251   return Ptr;
 252 }
 253
 254 // vim: sw=2 ai