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/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 : public FoldingSetNode {
 111   sys::cas_flag RefCount;
 112
 113   // AttributesList is uniqued, these should not be publicly available.
 114   void operator=(const AttributeListImpl &); // Do not implement
 115   AttributeListImpl(const AttributeListImpl &); // Do not implement
 116   ~AttributeListImpl();                        // Private implementation
 117 public:
 118   SmallVector<AttributeWithIndex, 4> Attrs;
 119
 120   AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
 121     : Attrs(Attr, Attr+NumAttrs) {
 122     RefCount = 0;
 123   }
 124
 125   void AddRef() { sys::AtomicIncrement(&RefCount); }
 126   void DropRef() {
 127     sys::cas_flag old = sys::AtomicDecrement(&RefCount);
 128     if (old == 0) delete this;
 129   }
 130
 131   void Profile(FoldingSetNodeID &ID) const {
 132     Profile(ID, Attrs.data(), Attrs.size());
 133   }
 134   static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
 135                       unsigned NumAttrs) {
 136     for (unsigned i = 0; i != NumAttrs; ++i)
 137       ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
 138   }
 139 };
 140 }
 141
 142 static ManagedStatic<sys::SmartMutex<true> > ALMutex;
 143 static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
 144
 145 AttributeListImpl::~AttributeListImpl() {
 146   sys::SmartScopedLock<true> Lock(*ALMutex);
 147   AttributesLists->RemoveNode(this);
 148 }
 149
 150
 151 AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
 152   // If there are no attributes then return a null AttributesList pointer.
 153   if (NumAttrs == 0)
 154     return AttrListPtr();
 155
 156 #ifndef NDEBUG
 157   for (unsigned i = 0; i != NumAttrs; ++i) {
 158     assert(Attrs[i].Attrs != Attribute::None &&
 159            "Pointless attribute!");
 160     assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
 161            "Misordered AttributesList!");
 162   }
 163 #endif
 164
 165   // Otherwise, build a key to look up the existing attributes.
 166   FoldingSetNodeID ID;
 167   AttributeListImpl::Profile(ID, Attrs, NumAttrs);
 168   void *InsertPos;
 169
 170   sys::SmartScopedLock<true> Lock(*ALMutex);
 171
 172   AttributeListImpl *PAL =
 173     AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
 174
 175   // If we didn't find any existing attributes of the same shape then
 176   // create a new one and insert it.
 177   if (!PAL) {
 178     PAL = new AttributeListImpl(Attrs, NumAttrs);
 179     AttributesLists->InsertNode(PAL, InsertPos);
 180   }
 181
 182   // Return the AttributesList that we found or created.
 183   return AttrListPtr(PAL);
 184 }
 185
 186
 187 //===----------------------------------------------------------------------===//
 188 // AttrListPtr Method Implementations
 189 //===----------------------------------------------------------------------===//
 190
 191 AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
 192   if (LI) LI->AddRef();
 193 }
 194
 195 AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
 196   if (AttrList) AttrList->AddRef();
 197 }
 198
 199 const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
 200   sys::SmartScopedLock<true> Lock(*ALMutex);
 201   if (AttrList == RHS.AttrList) return *this;
 202   if (AttrList) AttrList->DropRef();
 203   AttrList = RHS.AttrList;
 204   if (AttrList) AttrList->AddRef();
 205   return *this;
 206 }
 207
 208 AttrListPtr::~AttrListPtr() {
 209   if (AttrList) AttrList->DropRef();
 210 }
 211
 212 /// getNumSlots - Return the number of slots used in this attribute list.
 213 /// This is the number of arguments that have an attribute set on them
 214 /// (including the function itself).
 215 unsigned AttrListPtr::getNumSlots() const {
 216   return AttrList ? AttrList->Attrs.size() : 0;
 217 }
 218
 219 /// getSlot - Return the AttributeWithIndex at the specified slot.  This
 220 /// holds a number plus a set of attributes.
 221 const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
 222   assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
 223   return AttrList->Attrs[Slot];
 224 }
 225
 226
 227 /// getAttributes - The attributes for the specified index are
 228 /// returned.  Attributes for the result are denoted with Idx = 0.
 229 /// Function notes are denoted with idx = ~0.
 230 Attributes AttrListPtr::getAttributes(unsigned Idx) const {
 231   if (AttrList == 0) return Attribute::None;
 232
 233   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 234   for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
 235     if (Attrs[i].Index == Idx)
 236       return Attrs[i].Attrs;
 237   return Attribute::None;
 238 }
 239
 240 /// hasAttrSomewhere - Return true if the specified attribute is set for at
 241 /// least one parameter or for the return value.
 242 bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
 243   if (AttrList == 0) return false;
 244
 245   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 246   for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
 247     if (Attrs[i].Attrs & Attr)
 248       return true;
 249   return false;
 250 }
 251
 252
 253 AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
 254   Attributes OldAttrs = getAttributes(Idx);
 255 #ifndef NDEBUG
 256   // FIXME it is not obvious how this should work for alignment.
 257   // For now, say we can't change a known alignment.
 258   Attributes OldAlign = OldAttrs & Attribute::Alignment;
 259   Attributes NewAlign = Attrs & Attribute::Alignment;
 260   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
 261          "Attempt to change alignment!");
 262 #endif
 263
 264   Attributes NewAttrs = OldAttrs | Attrs;
 265   if (NewAttrs == OldAttrs)
 266     return *this;
 267
 268   SmallVector<AttributeWithIndex, 8> NewAttrList;
 269   if (AttrList == 0)
 270     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 271   else {
 272     const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 273     unsigned i = 0, e = OldAttrList.size();
 274     // Copy attributes for arguments before this one.
 275     for (; i != e && OldAttrList[i].Index < Idx; ++i)
 276       NewAttrList.push_back(OldAttrList[i]);
 277
 278     // If there are attributes already at this index, merge them in.
 279     if (i != e && OldAttrList[i].Index == Idx) {
 280       Attrs |= OldAttrList[i].Attrs;
 281       ++i;
 282     }
 283
 284     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 285
 286     // Copy attributes for arguments after this one.
 287     NewAttrList.insert(NewAttrList.end(),
 288                        OldAttrList.begin()+i, OldAttrList.end());
 289   }
 290
 291   return get(NewAttrList.data(), NewAttrList.size());
 292 }
 293
 294 AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
 295 #ifndef NDEBUG
 296   // FIXME it is not obvious how this should work for alignment.
 297   // For now, say we can't pass in alignment, which no current use does.
 298   assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
 299 #endif
 300   if (AttrList == 0) return AttrListPtr();
 301
 302   Attributes OldAttrs = getAttributes(Idx);
 303   Attributes NewAttrs = OldAttrs & ~Attrs;
 304   if (NewAttrs == OldAttrs)
 305     return *this;
 306
 307   SmallVector<AttributeWithIndex, 8> NewAttrList;
 308   const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 309   unsigned i = 0, e = OldAttrList.size();
 310
 311   // Copy attributes for arguments before this one.
 312   for (; i != e && OldAttrList[i].Index < Idx; ++i)
 313     NewAttrList.push_back(OldAttrList[i]);
 314
 315   // If there are attributes already at this index, merge them in.
 316   assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
 317   Attrs = OldAttrList[i].Attrs & ~Attrs;
 318   ++i;
 319   if (Attrs)  // If any attributes left for this parameter, add them.
 320     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 321
 322   // Copy attributes for arguments after this one.
 323   NewAttrList.insert(NewAttrList.end(),
 324                      OldAttrList.begin()+i, OldAttrList.end());
 325
 326   return get(NewAttrList.data(), NewAttrList.size());
 327 }
 328
 329 void AttrListPtr::dump() const {
 330   dbgs() << "PAL[ ";
 331   for (unsigned i = 0; i < getNumSlots(); ++i) {
 332     const AttributeWithIndex &PAWI = getSlot(i);
 333     dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
 334   }
 335
 336   dbgs() << "]\n";
 337 }