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/System/Atomic.h"
  19 #include "llvm/System/Mutex.h"
  20 #include "llvm/Support/ManagedStatic.h"
  21 #include "llvm/Support/raw_ostream.h"
  22 using namespace llvm;
  23
  24 //===----------------------------------------------------------------------===//
  25 // Attribute Function Definitions
  26 //===----------------------------------------------------------------------===//
  27
  28 std::string Attribute::getAsString(Attributes Attrs) {
  29   std::string Result;
  30   if (Attrs & Attribute::ZExt)
  31     Result += "zeroext ";
  32   if (Attrs & Attribute::SExt)
  33     Result += "signext ";
  34   if (Attrs & Attribute::NoReturn)
  35     Result += "noreturn ";
  36   if (Attrs & Attribute::NoUnwind)
  37     Result += "nounwind ";
  38   if (Attrs & Attribute::InReg)
  39     Result += "inreg ";
  40   if (Attrs & Attribute::NoAlias)
  41     Result += "noalias ";
  42   if (Attrs & Attribute::NoCapture)
  43     Result += "nocapture ";
  44   if (Attrs & Attribute::StructRet)
  45     Result += "sret ";
  46   if (Attrs & Attribute::ByVal)
  47     Result += "byval ";
  48   if (Attrs & Attribute::Nest)
  49     Result += "nest ";
  50   if (Attrs & Attribute::ReadNone)
  51     Result += "readnone ";
  52   if (Attrs & Attribute::ReadOnly)
  53     Result += "readonly ";
  54   if (Attrs & Attribute::OptimizeForSize)
  55     Result += "optsize ";
  56   if (Attrs & Attribute::NoInline)
  57     Result += "noinline ";
  58   if (Attrs & Attribute::InlineHint)
  59     Result += "inlinehint ";
  60   if (Attrs & Attribute::AlwaysInline)
  61     Result += "alwaysinline ";
  62   if (Attrs & Attribute::StackProtect)
  63     Result += "ssp ";
  64   if (Attrs & Attribute::StackProtectReq)
  65     Result += "sspreq ";
  66   if (Attrs & Attribute::NoRedZone)
  67     Result += "noredzone ";
  68   if (Attrs & Attribute::NoImplicitFloat)
  69     Result += "noimplicitfloat ";
  70   if (Attrs & Attribute::Naked)
  71     Result += "naked ";
  72   if (Attrs & Attribute::Alignment) {
  73     Result += "align ";
  74     Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
  75     Result += " ";
  76   }
  77   // Trim the trailing space.
  78   assert(!Result.empty() && "Unknown attribute!");
  79   Result.erase(Result.end()-1);
  80   return Result;
  81 }
  82
  83 Attributes Attribute::typeIncompatible(const Type *Ty) {
  84   Attributes Incompatible = None;
  85
  86   if (!Ty->isInteger())
  87     // Attributes that only apply to integers.
  88     Incompatible |= SExt | ZExt;
  89
  90   if (!isa<PointerType>(Ty))
  91     // Attributes that only apply to pointers.
  92     Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
  93
  94   return Incompatible;
  95 }
  96
  97 //===----------------------------------------------------------------------===//
  98 // AttributeListImpl Definition
  99 //===----------------------------------------------------------------------===//
 100
 101 namespace llvm {
 102 class AttributeListImpl : public FoldingSetNode {
 103   sys::cas_flag RefCount;
 104
 105   // AttributesList is uniqued, these should not be publicly available.
 106   void operator=(const AttributeListImpl &); // Do not implement
 107   AttributeListImpl(const AttributeListImpl &); // Do not implement
 108   ~AttributeListImpl();                        // Private implementation
 109 public:
 110   SmallVector<AttributeWithIndex, 4> Attrs;
 111
 112   AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
 113     : Attrs(Attr, Attr+NumAttrs) {
 114     RefCount = 0;
 115   }
 116
 117   void AddRef() { sys::AtomicIncrement(&RefCount); }
 118   void DropRef() {
 119     sys::cas_flag old = sys::AtomicDecrement(&RefCount);
 120     if (old == 0) delete this;
 121   }
 122
 123   void Profile(FoldingSetNodeID &ID) const {
 124     Profile(ID, Attrs.data(), Attrs.size());
 125   }
 126   static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
 127                       unsigned NumAttrs) {
 128     for (unsigned i = 0; i != NumAttrs; ++i)
 129       ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
 130   }
 131 };
 132 }
 133
 134 static ManagedStatic<sys::SmartMutex<true> > ALMutex;
 135 static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
 136
 137 AttributeListImpl::~AttributeListImpl() {
 138   sys::SmartScopedLock<true> Lock(*ALMutex);
 139   AttributesLists->RemoveNode(this);
 140 }
 141
 142
 143 AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
 144   // If there are no attributes then return a null AttributesList pointer.
 145   if (NumAttrs == 0)
 146     return AttrListPtr();
 147
 148 #ifndef NDEBUG
 149   for (unsigned i = 0; i != NumAttrs; ++i) {
 150     assert(Attrs[i].Attrs != Attribute::None &&
 151            "Pointless attribute!");
 152     assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
 153            "Misordered AttributesList!");
 154   }
 155 #endif
 156
 157   // Otherwise, build a key to look up the existing attributes.
 158   FoldingSetNodeID ID;
 159   AttributeListImpl::Profile(ID, Attrs, NumAttrs);
 160   void *InsertPos;
 161
 162   sys::SmartScopedLock<true> Lock(*ALMutex);
 163
 164   AttributeListImpl *PAL =
 165     AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
 166
 167   // If we didn't find any existing attributes of the same shape then
 168   // create a new one and insert it.
 169   if (!PAL) {
 170     PAL = new AttributeListImpl(Attrs, NumAttrs);
 171     AttributesLists->InsertNode(PAL, InsertPos);
 172   }
 173
 174   // Return the AttributesList that we found or created.
 175   return AttrListPtr(PAL);
 176 }
 177
 178
 179 //===----------------------------------------------------------------------===//
 180 // AttrListPtr Method Implementations
 181 //===----------------------------------------------------------------------===//
 182
 183 AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
 184   if (LI) LI->AddRef();
 185 }
 186
 187 AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
 188   if (AttrList) AttrList->AddRef();
 189 }
 190
 191 const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
 192   if (AttrList == RHS.AttrList) return *this;
 193   if (AttrList) AttrList->DropRef();
 194   AttrList = RHS.AttrList;
 195   if (AttrList) AttrList->AddRef();
 196   return *this;
 197 }
 198
 199 AttrListPtr::~AttrListPtr() {
 200   if (AttrList) AttrList->DropRef();
 201 }
 202
 203 /// getNumSlots - Return the number of slots used in this attribute list.
 204 /// This is the number of arguments that have an attribute set on them
 205 /// (including the function itself).
 206 unsigned AttrListPtr::getNumSlots() const {
 207   return AttrList ? AttrList->Attrs.size() : 0;
 208 }
 209
 210 /// getSlot - Return the AttributeWithIndex at the specified slot.  This
 211 /// holds a number plus a set of attributes.
 212 const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
 213   assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
 214   return AttrList->Attrs[Slot];
 215 }
 216
 217
 218 /// getAttributes - The attributes for the specified index are
 219 /// returned.  Attributes for the result are denoted with Idx = 0.
 220 /// Function notes are denoted with idx = ~0.
 221 Attributes AttrListPtr::getAttributes(unsigned Idx) const {
 222   if (AttrList == 0) return Attribute::None;
 223
 224   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 225   for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
 226     if (Attrs[i].Index == Idx)
 227       return Attrs[i].Attrs;
 228   return Attribute::None;
 229 }
 230
 231 /// hasAttrSomewhere - Return true if the specified attribute is set for at
 232 /// least one parameter or for the return value.
 233 bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
 234   if (AttrList == 0) return false;
 235
 236   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 237   for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
 238     if (Attrs[i].Attrs & Attr)
 239       return true;
 240   return false;
 241 }
 242
 243
 244 AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
 245   Attributes OldAttrs = getAttributes(Idx);
 246 #ifndef NDEBUG
 247   // FIXME it is not obvious how this should work for alignment.
 248   // For now, say we can't change a known alignment.
 249   Attributes OldAlign = OldAttrs & Attribute::Alignment;
 250   Attributes NewAlign = Attrs & Attribute::Alignment;
 251   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
 252          "Attempt to change alignment!");
 253 #endif
 254
 255   Attributes NewAttrs = OldAttrs | Attrs;
 256   if (NewAttrs == OldAttrs)
 257     return *this;
 258
 259   SmallVector<AttributeWithIndex, 8> NewAttrList;
 260   if (AttrList == 0)
 261     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 262   else {
 263     const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 264     unsigned i = 0, e = OldAttrList.size();
 265     // Copy attributes for arguments before this one.
 266     for (; i != e && OldAttrList[i].Index < Idx; ++i)
 267       NewAttrList.push_back(OldAttrList[i]);
 268
 269     // If there are attributes already at this index, merge them in.
 270     if (i != e && OldAttrList[i].Index == Idx) {
 271       Attrs |= OldAttrList[i].Attrs;
 272       ++i;
 273     }
 274
 275     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 276
 277     // Copy attributes for arguments after this one.
 278     NewAttrList.insert(NewAttrList.end(),
 279                        OldAttrList.begin()+i, OldAttrList.end());
 280   }
 281
 282   return get(NewAttrList.data(), NewAttrList.size());
 283 }
 284
 285 AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
 286 #ifndef NDEBUG
 287   // FIXME it is not obvious how this should work for alignment.
 288   // For now, say we can't pass in alignment, which no current use does.
 289   assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
 290 #endif
 291   if (AttrList == 0) return AttrListPtr();
 292
 293   Attributes OldAttrs = getAttributes(Idx);
 294   Attributes NewAttrs = OldAttrs & ~Attrs;
 295   if (NewAttrs == OldAttrs)
 296     return *this;
 297
 298   SmallVector<AttributeWithIndex, 8> NewAttrList;
 299   const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 300   unsigned i = 0, e = OldAttrList.size();
 301
 302   // Copy attributes for arguments before this one.
 303   for (; i != e && OldAttrList[i].Index < Idx; ++i)
 304     NewAttrList.push_back(OldAttrList[i]);
 305
 306   // If there are attributes already at this index, merge them in.
 307   assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
 308   Attrs = OldAttrList[i].Attrs & ~Attrs;
 309   ++i;
 310   if (Attrs)  // If any attributes left for this parameter, add them.
 311     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 312
 313   // Copy attributes for arguments after this one.
 314   NewAttrList.insert(NewAttrList.end(),
 315                      OldAttrList.begin()+i, OldAttrList.end());
 316
 317   return get(NewAttrList.data(), NewAttrList.size());
 318 }
 319
 320 void AttrListPtr::dump() const {
 321   errs() << "PAL[ ";
 322   for (unsigned i = 0; i < getNumSlots(); ++i) {
 323     const AttributeWithIndex &PAWI = getSlot(i);
 324     errs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
 325   }
 326
 327   errs() << "]\n";
 328 }