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/Atomic.h"
  19 #include "llvm/Support/Mutex.h"
  20 #include "llvm/Support/Debug.h"
  21 #include "llvm/Support/ManagedStatic.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 using namespace llvm;
  24
  25 //===----------------------------------------------------------------------===//
  26 // Attribute Function Definitions
  27 //===----------------------------------------------------------------------===//
  28
  29 std::string Attribute::getAsString(Attributes Attrs) {
  30   std::string Result;
  31   if (Attrs & Attribute::ZExt)
  32     Result += "zeroext ";
  33   if (Attrs & Attribute::SExt)
  34     Result += "signext ";
  35   if (Attrs & Attribute::NoReturn)
  36     Result += "noreturn ";
  37   if (Attrs & Attribute::NoUnwind)
  38     Result += "nounwind ";
  39   if (Attrs & Attribute::InReg)
  40     Result += "inreg ";
  41   if (Attrs & Attribute::NoAlias)
  42     Result += "noalias ";
  43   if (Attrs & Attribute::NoCapture)
  44     Result += "nocapture ";
  45   if (Attrs & Attribute::StructRet)
  46     Result += "sret ";
  47   if (Attrs & Attribute::ByVal)
  48     Result += "byval ";
  49   if (Attrs & Attribute::Nest)
  50     Result += "nest ";
  51   if (Attrs & Attribute::ReadNone)
  52     Result += "readnone ";
  53   if (Attrs & Attribute::ReadOnly)
  54     Result += "readonly ";
  55   if (Attrs & Attribute::OptimizeForSize)
  56     Result += "optsize ";
  57   if (Attrs & Attribute::NoInline)
  58     Result += "noinline ";
  59   if (Attrs & Attribute::InlineHint)
  60     Result += "inlinehint ";
  61   if (Attrs & Attribute::AlwaysInline)
  62     Result += "alwaysinline ";
  63   if (Attrs & Attribute::StackProtect)
  64     Result += "ssp ";
  65   if (Attrs & Attribute::StackProtectReq)
  66     Result += "sspreq ";
  67   if (Attrs & Attribute::NoRedZone)
  68     Result += "noredzone ";
  69   if (Attrs & Attribute::NoImplicitFloat)
  70     Result += "noimplicitfloat ";
  71   if (Attrs & Attribute::Naked)
  72     Result += "naked ";
  73   if (Attrs & Attribute::Hotpatch)
  74     Result += "hotpatch ";
  75   if (Attrs & Attribute::StackAlignment) {
  76     Result += "alignstack(";
  77     Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs));
  78     Result += ") ";
  79   }
  80   if (Attrs & Attribute::Alignment) {
  81     Result += "align ";
  82     Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
  83     Result += " ";
  84   }
  85   // Trim the trailing space.
  86   assert(!Result.empty() && "Unknown attribute!");
  87   Result.erase(Result.end()-1);
  88   return Result;
  89 }
  90
  91 Attributes Attribute::typeIncompatible(const Type *Ty) {
  92   Attributes Incompatible = None;
  93
  94   if (!Ty->isIntegerTy())
  95     // Attributes that only apply to integers.
  96     Incompatible |= SExt | ZExt;
  97
  98   if (!Ty->isPointerTy())
  99     // Attributes that only apply to pointers.
 100     Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
 101
 102   return Incompatible;
 103 }
 104
 105 //===----------------------------------------------------------------------===//
 106 // AttributeListImpl Definition
 107 //===----------------------------------------------------------------------===//
 108
 109 namespace llvm {
 110   class AttributeListImpl;
 111 }
 112
 113 static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
 114
 115 namespace llvm {
 116 static ManagedStatic<sys::SmartMutex<true> > ALMutex;
 117
 118 class AttributeListImpl : public FoldingSetNode {
 119   sys::cas_flag RefCount;
 120
 121   // AttributesList is uniqued, these should not be publicly available.
 122   void operator=(const AttributeListImpl &); // Do not implement
 123   AttributeListImpl(const AttributeListImpl &); // Do not implement
 124   ~AttributeListImpl();                        // Private implementation
 125 public:
 126   SmallVector<AttributeWithIndex, 4> Attrs;
 127
 128   AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
 129     : Attrs(Attr, Attr+NumAttrs) {
 130     RefCount = 0;
 131   }
 132
 133   void AddRef() {
 134     sys::SmartScopedLock<true> Lock(*ALMutex);
 135     ++RefCount;
 136   }
 137   void DropRef() {
 138     sys::SmartScopedLock<true> Lock(*ALMutex);
 139     if (!AttributesLists.isConstructed())
 140       return;
 141     sys::cas_flag new_val = --RefCount;
 142     if (new_val == 0)
 143       delete this;
 144   }
 145
 146   void Profile(FoldingSetNodeID &ID) const {
 147     Profile(ID, Attrs.data(), Attrs.size());
 148   }
 149   static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
 150                       unsigned NumAttrs) {
 151     for (unsigned i = 0; i != NumAttrs; ++i)
 152       ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
 153   }
 154 };
 155 }
 156
 157 AttributeListImpl::~AttributeListImpl() {
 158   // NOTE: Lock must be acquired by caller.
 159   AttributesLists->RemoveNode(this);
 160 }
 161
 162
 163 AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
 164   // If there are no attributes then return a null AttributesList pointer.
 165   if (NumAttrs == 0)
 166     return AttrListPtr();
 167
 168 #ifndef NDEBUG
 169   for (unsigned i = 0; i != NumAttrs; ++i) {
 170     assert(Attrs[i].Attrs != Attribute::None &&
 171            "Pointless attribute!");
 172     assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
 173            "Misordered AttributesList!");
 174   }
 175 #endif
 176
 177   // Otherwise, build a key to look up the existing attributes.
 178   FoldingSetNodeID ID;
 179   AttributeListImpl::Profile(ID, Attrs, NumAttrs);
 180   void *InsertPos;
 181
 182   sys::SmartScopedLock<true> Lock(*ALMutex);
 183
 184   AttributeListImpl *PAL =
 185     AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
 186
 187   // If we didn't find any existing attributes of the same shape then
 188   // create a new one and insert it.
 189   if (!PAL) {
 190     PAL = new AttributeListImpl(Attrs, NumAttrs);
 191     AttributesLists->InsertNode(PAL, InsertPos);
 192   }
 193
 194   // Return the AttributesList that we found or created.
 195   return AttrListPtr(PAL);
 196 }
 197
 198
 199 //===----------------------------------------------------------------------===//
 200 // AttrListPtr Method Implementations
 201 //===----------------------------------------------------------------------===//
 202
 203 AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
 204   if (LI) LI->AddRef();
 205 }
 206
 207 AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
 208   if (AttrList) AttrList->AddRef();
 209 }
 210
 211 const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
 212   sys::SmartScopedLock<true> Lock(*ALMutex);
 213   if (AttrList == RHS.AttrList) return *this;
 214   if (AttrList) AttrList->DropRef();
 215   AttrList = RHS.AttrList;
 216   if (AttrList) AttrList->AddRef();
 217   return *this;
 218 }
 219
 220 AttrListPtr::~AttrListPtr() {
 221   if (AttrList) AttrList->DropRef();
 222 }
 223
 224 /// getNumSlots - Return the number of slots used in this attribute list.
 225 /// This is the number of arguments that have an attribute set on them
 226 /// (including the function itself).
 227 unsigned AttrListPtr::getNumSlots() const {
 228   return AttrList ? AttrList->Attrs.size() : 0;
 229 }
 230
 231 /// getSlot - Return the AttributeWithIndex at the specified slot.  This
 232 /// holds a number plus a set of attributes.
 233 const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
 234   assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
 235   return AttrList->Attrs[Slot];
 236 }
 237
 238
 239 /// getAttributes - The attributes for the specified index are
 240 /// returned.  Attributes for the result are denoted with Idx = 0.
 241 /// Function notes are denoted with idx = ~0.
 242 Attributes AttrListPtr::getAttributes(unsigned Idx) const {
 243   if (AttrList == 0) return Attribute::None;
 244
 245   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 246   for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
 247     if (Attrs[i].Index == Idx)
 248       return Attrs[i].Attrs;
 249   return Attribute::None;
 250 }
 251
 252 /// hasAttrSomewhere - Return true if the specified attribute is set for at
 253 /// least one parameter or for the return value.
 254 bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
 255   if (AttrList == 0) return false;
 256
 257   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 258   for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
 259     if (Attrs[i].Attrs & Attr)
 260       return true;
 261   return false;
 262 }
 263
 264
 265 AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
 266   Attributes OldAttrs = getAttributes(Idx);
 267 #ifndef NDEBUG
 268   // FIXME it is not obvious how this should work for alignment.
 269   // For now, say we can't change a known alignment.
 270   Attributes OldAlign = OldAttrs & Attribute::Alignment;
 271   Attributes NewAlign = Attrs & Attribute::Alignment;
 272   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
 273          "Attempt to change alignment!");
 274 #endif
 275
 276   Attributes NewAttrs = OldAttrs | Attrs;
 277   if (NewAttrs == OldAttrs)
 278     return *this;
 279
 280   SmallVector<AttributeWithIndex, 8> NewAttrList;
 281   if (AttrList == 0)
 282     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 283   else {
 284     const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 285     unsigned i = 0, e = OldAttrList.size();
 286     // Copy attributes for arguments before this one.
 287     for (; i != e && OldAttrList[i].Index < Idx; ++i)
 288       NewAttrList.push_back(OldAttrList[i]);
 289
 290     // If there are attributes already at this index, merge them in.
 291     if (i != e && OldAttrList[i].Index == Idx) {
 292       Attrs |= OldAttrList[i].Attrs;
 293       ++i;
 294     }
 295
 296     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 297
 298     // Copy attributes for arguments after this one.
 299     NewAttrList.insert(NewAttrList.end(),
 300                        OldAttrList.begin()+i, OldAttrList.end());
 301   }
 302
 303   return get(NewAttrList.data(), NewAttrList.size());
 304 }
 305
 306 AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
 307 #ifndef NDEBUG
 308   // FIXME it is not obvious how this should work for alignment.
 309   // For now, say we can't pass in alignment, which no current use does.
 310   assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
 311 #endif
 312   if (AttrList == 0) return AttrListPtr();
 313
 314   Attributes OldAttrs = getAttributes(Idx);
 315   Attributes NewAttrs = OldAttrs & ~Attrs;
 316   if (NewAttrs == OldAttrs)
 317     return *this;
 318
 319   SmallVector<AttributeWithIndex, 8> NewAttrList;
 320   const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 321   unsigned i = 0, e = OldAttrList.size();
 322
 323   // Copy attributes for arguments before this one.
 324   for (; i != e && OldAttrList[i].Index < Idx; ++i)
 325     NewAttrList.push_back(OldAttrList[i]);
 326
 327   // If there are attributes already at this index, merge them in.
 328   assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
 329   Attrs = OldAttrList[i].Attrs & ~Attrs;
 330   ++i;
 331   if (Attrs)  // If any attributes left for this parameter, add them.
 332     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 333
 334   // Copy attributes for arguments after this one.
 335   NewAttrList.insert(NewAttrList.end(),
 336                      OldAttrList.begin()+i, OldAttrList.end());
 337
 338   return get(NewAttrList.data(), NewAttrList.size());
 339 }
 340
 341 void AttrListPtr::dump() const {
 342   dbgs() << "PAL[ ";
 343   for (unsigned i = 0; i < getNumSlots(); ++i) {
 344     const AttributeWithIndex &PAWI = getSlot(i);
 345     dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
 346   }
 347
 348   dbgs() << "]\n";
 349 }