lib/VMCore/Attributes.cpp

   1 //===-- Attributes.cpp - Implement AttributesList -------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements the AttributesList class and Attribute utilities.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Attributes.h"
  15 #include "llvm/Type.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/ADT/FoldingSet.h"
  18 #include "llvm/Support/Streams.h"
  19 #include "llvm/Support/ManagedStatic.h"
  20 using namespace llvm;
  21
  22 //===----------------------------------------------------------------------===//
  23 // Attribute Function Definitions
  24 //===----------------------------------------------------------------------===//
  25
  26 std::string Attribute::getAsString(Attributes Attrs) {
  27   std::string Result;
  28   if (Attrs & Attribute::ZExt)
  29     Result += "zeroext ";
  30   if (Attrs & Attribute::SExt)
  31     Result += "signext ";
  32   if (Attrs & Attribute::NoReturn)
  33     Result += "noreturn ";
  34   if (Attrs & Attribute::NoUnwind)
  35     Result += "nounwind ";
  36   if (Attrs & Attribute::InReg)
  37     Result += "inreg ";
  38   if (Attrs & Attribute::NoAlias)
  39     Result += "noalias ";
  40   if (Attrs & Attribute::NoCapture)
  41     Result += "nocapture ";
  42   if (Attrs & Attribute::StructRet)
  43     Result += "sret ";
  44   if (Attrs & Attribute::ByVal)
  45     Result += "byval ";
  46   if (Attrs & Attribute::Nest)
  47     Result += "nest ";
  48   if (Attrs & Attribute::ReadNone)
  49     Result += "readnone ";
  50   if (Attrs & Attribute::ReadOnly)
  51     Result += "readonly ";
  52   if (Attrs & Attribute::OptimizeForSize)
  53     Result += "optsize ";
  54   if (Attrs & Attribute::NoInline)
  55     Result += "noinline ";
  56   if (Attrs & Attribute::AlwaysInline)
  57     Result += "alwaysinline ";
  58   if (Attrs & Attribute::StackProtect)
  59     Result += "ssp ";
  60   if (Attrs & Attribute::StackProtectReq)
  61     Result += "sspreq ";
  62   if (Attrs & Attribute::NoRedZone)
  63     Result += "noredzone ";
  64   if (Attrs & Attribute::NoImplicitFloat)
  65     Result += "noimplicitfloat ";
  66   if (Attrs & Attribute::Naked)
  67     Result += "naked ";
  68   if (Attrs & Attribute::Alignment) {
  69     Result += "align ";
  70     Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
  71     Result += " ";
  72   }
  73   // Trim the trailing space.
  74   assert(!Result.empty() && "Unknown attribute!");
  75   Result.erase(Result.end()-1);
  76   return Result;
  77 }
  78
  79 Attributes Attribute::typeIncompatible(const Type *Ty) {
  80   Attributes Incompatible = None;
  81
  82   if (!Ty->isInteger())
  83     // Attributes that only apply to integers.
  84     Incompatible |= SExt | ZExt;
  85
  86   if (!isa<PointerType>(Ty))
  87     // Attributes that only apply to pointers.
  88     Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
  89
  90   return Incompatible;
  91 }
  92
  93 //===----------------------------------------------------------------------===//
  94 // AttributeListImpl Definition
  95 //===----------------------------------------------------------------------===//
  96
  97 namespace llvm {
  98 class AttributeListImpl : public FoldingSetNode {
  99   unsigned RefCount;
 100
 101   // AttributesList is uniqued, these should not be publicly available.
 102   void operator=(const AttributeListImpl &); // Do not implement
 103   AttributeListImpl(const AttributeListImpl &); // Do not implement
 104   ~AttributeListImpl();                        // Private implementation
 105 public:
 106   SmallVector<AttributeWithIndex, 4> Attrs;
 107
 108   AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
 109     : Attrs(Attr, Attr+NumAttrs) {
 110     RefCount = 0;
 111   }
 112
 113   void AddRef() { ++RefCount; }
 114   void DropRef() { if (--RefCount == 0) delete this; }
 115
 116   void Profile(FoldingSetNodeID &ID) const {
 117     Profile(ID, Attrs.data(), Attrs.size());
 118   }
 119   static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
 120                       unsigned NumAttrs) {
 121     for (unsigned i = 0; i != NumAttrs; ++i)
 122       ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
 123   }
 124 };
 125 }
 126
 127 static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
 128
 129 AttributeListImpl::~AttributeListImpl() {
 130   AttributesLists->RemoveNode(this);
 131 }
 132
 133
 134 AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
 135   // If there are no attributes then return a null AttributesList pointer.
 136   if (NumAttrs == 0)
 137     return AttrListPtr();
 138
 139 #ifndef NDEBUG
 140   for (unsigned i = 0; i != NumAttrs; ++i) {
 141     assert(Attrs[i].Attrs != Attribute::None &&
 142            "Pointless attribute!");
 143     assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
 144            "Misordered AttributesList!");
 145   }
 146 #endif
 147
 148   // Otherwise, build a key to look up the existing attributes.
 149   FoldingSetNodeID ID;
 150   AttributeListImpl::Profile(ID, Attrs, NumAttrs);
 151   void *InsertPos;
 152   AttributeListImpl *PAL =
 153     AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
 154
 155   // If we didn't find any existing attributes of the same shape then
 156   // create a new one and insert it.
 157   if (!PAL) {
 158     PAL = new AttributeListImpl(Attrs, NumAttrs);
 159     AttributesLists->InsertNode(PAL, InsertPos);
 160   }
 161
 162   // Return the AttributesList that we found or created.
 163   return AttrListPtr(PAL);
 164 }
 165
 166
 167 //===----------------------------------------------------------------------===//
 168 // AttrListPtr Method Implementations
 169 //===----------------------------------------------------------------------===//
 170
 171 AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
 172   if (LI) LI->AddRef();
 173 }
 174
 175 AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
 176   if (AttrList) AttrList->AddRef();
 177 }
 178
 179 const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
 180   if (AttrList == RHS.AttrList) return *this;
 181   if (AttrList) AttrList->DropRef();
 182   AttrList = RHS.AttrList;
 183   if (AttrList) AttrList->AddRef();
 184   return *this;
 185 }
 186
 187 AttrListPtr::~AttrListPtr() {
 188   if (AttrList) AttrList->DropRef();
 189 }
 190
 191 /// getNumSlots - Return the number of slots used in this attribute list.
 192 /// This is the number of arguments that have an attribute set on them
 193 /// (including the function itself).
 194 unsigned AttrListPtr::getNumSlots() const {
 195   return AttrList ? AttrList->Attrs.size() : 0;
 196 }
 197
 198 /// getSlot - Return the AttributeWithIndex at the specified slot.  This
 199 /// holds a number plus a set of attributes.
 200 const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
 201   assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
 202   return AttrList->Attrs[Slot];
 203 }
 204
 205
 206 /// getAttributes - The attributes for the specified index are
 207 /// returned.  Attributes for the result are denoted with Idx = 0.
 208 /// Function notes are denoted with idx = ~0.
 209 Attributes AttrListPtr::getAttributes(unsigned Idx) const {
 210   if (AttrList == 0) return Attribute::None;
 211
 212   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 213   for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
 214     if (Attrs[i].Index == Idx)
 215       return Attrs[i].Attrs;
 216   return Attribute::None;
 217 }
 218
 219 /// hasAttrSomewhere - Return true if the specified attribute is set for at
 220 /// least one parameter or for the return value.
 221 bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
 222   if (AttrList == 0) return false;
 223
 224   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 225   for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
 226     if (Attrs[i].Attrs & Attr)
 227       return true;
 228   return false;
 229 }
 230
 231
 232 AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
 233   Attributes OldAttrs = getAttributes(Idx);
 234 #ifndef NDEBUG
 235   // FIXME it is not obvious how this should work for alignment.
 236   // For now, say we can't change a known alignment.
 237   Attributes OldAlign = OldAttrs & Attribute::Alignment;
 238   Attributes NewAlign = Attrs & Attribute::Alignment;
 239   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
 240          "Attempt to change alignment!");
 241 #endif
 242
 243   Attributes NewAttrs = OldAttrs | Attrs;
 244   if (NewAttrs == OldAttrs)
 245     return *this;
 246
 247   SmallVector<AttributeWithIndex, 8> NewAttrList;
 248   if (AttrList == 0)
 249     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 250   else {
 251     const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 252     unsigned i = 0, e = OldAttrList.size();
 253     // Copy attributes for arguments before this one.
 254     for (; i != e && OldAttrList[i].Index < Idx; ++i)
 255       NewAttrList.push_back(OldAttrList[i]);
 256
 257     // If there are attributes already at this index, merge them in.
 258     if (i != e && OldAttrList[i].Index == Idx) {
 259       Attrs |= OldAttrList[i].Attrs;
 260       ++i;
 261     }
 262
 263     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 264
 265     // Copy attributes for arguments after this one.
 266     NewAttrList.insert(NewAttrList.end(),
 267                        OldAttrList.begin()+i, OldAttrList.end());
 268   }
 269
 270   return get(NewAttrList.data(), NewAttrList.size());
 271 }
 272
 273 AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
 274 #ifndef NDEBUG
 275   // FIXME it is not obvious how this should work for alignment.
 276   // For now, say we can't pass in alignment, which no current use does.
 277   assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
 278 #endif
 279   if (AttrList == 0) return AttrListPtr();
 280
 281   Attributes OldAttrs = getAttributes(Idx);
 282   Attributes NewAttrs = OldAttrs & ~Attrs;
 283   if (NewAttrs == OldAttrs)
 284     return *this;
 285
 286   SmallVector<AttributeWithIndex, 8> NewAttrList;
 287   const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 288   unsigned i = 0, e = OldAttrList.size();
 289
 290   // Copy attributes for arguments before this one.
 291   for (; i != e && OldAttrList[i].Index < Idx; ++i)
 292     NewAttrList.push_back(OldAttrList[i]);
 293
 294   // If there are attributes already at this index, merge them in.
 295   assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
 296   Attrs = OldAttrList[i].Attrs & ~Attrs;
 297   ++i;
 298   if (Attrs)  // If any attributes left for this parameter, add them.
 299     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 300
 301   // Copy attributes for arguments after this one.
 302   NewAttrList.insert(NewAttrList.end(),
 303                      OldAttrList.begin()+i, OldAttrList.end());
 304
 305   return get(NewAttrList.data(), NewAttrList.size());
 306 }
 307
 308 void AttrListPtr::dump() const {
 309   cerr << "PAL[ ";
 310   for (unsigned i = 0; i < getNumSlots(); ++i) {
 311     const AttributeWithIndex &PAWI = getSlot(i);
 312     cerr << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
 313   }
 314
 315   cerr << "]\n";
 316 }