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::UWTable)
  40     Result += "uwtable ";
  41   if (Attrs & Attribute::InReg)
  42     Result += "inreg ";
  43   if (Attrs & Attribute::NoAlias)
  44     Result += "noalias ";
  45   if (Attrs & Attribute::NoCapture)
  46     Result += "nocapture ";
  47   if (Attrs & Attribute::StructRet)
  48     Result += "sret ";
  49   if (Attrs & Attribute::ByVal)
  50     Result += "byval ";
  51   if (Attrs & Attribute::Nest)
  52     Result += "nest ";
  53   if (Attrs & Attribute::ReadNone)
  54     Result += "readnone ";
  55   if (Attrs & Attribute::ReadOnly)
  56     Result += "readonly ";
  57   if (Attrs & Attribute::OptimizeForSize)
  58     Result += "optsize ";
  59   if (Attrs & Attribute::NoInline)
  60     Result += "noinline ";
  61   if (Attrs & Attribute::InlineHint)
  62     Result += "inlinehint ";
  63   if (Attrs & Attribute::AlwaysInline)
  64     Result += "alwaysinline ";
  65   if (Attrs & Attribute::StackProtect)
  66     Result += "ssp ";
  67   if (Attrs & Attribute::StackProtectReq)
  68     Result += "sspreq ";
  69   if (Attrs & Attribute::NoRedZone)
  70     Result += "noredzone ";
  71   if (Attrs & Attribute::NoImplicitFloat)
  72     Result += "noimplicitfloat ";
  73   if (Attrs & Attribute::Naked)
  74     Result += "naked ";
  75   if (Attrs & Attribute::Hotpatch)
  76     Result += "hotpatch ";
  77   if (Attrs & Attribute::NonLazyBind)
  78     Result += "nonlazybind ";
  79   if (Attrs & Attribute::StackAlignment) {
  80     Result += "alignstack(";
  81     Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs));
  82     Result += ") ";
  83   }
  84   if (Attrs & Attribute::Alignment) {
  85     Result += "align ";
  86     Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
  87     Result += " ";
  88   }
  89   // Trim the trailing space.
  90   assert(!Result.empty() && "Unknown attribute!");
  91   Result.erase(Result.end()-1);
  92   return Result;
  93 }
  94
  95 Attributes Attribute::typeIncompatible(const Type *Ty) {
  96   Attributes Incompatible = None;
  97
  98   if (!Ty->isIntegerTy())
  99     // Attributes that only apply to integers.
 100     Incompatible |= SExt | ZExt;
 101
 102   if (!Ty->isPointerTy())
 103     // Attributes that only apply to pointers.
 104     Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
 105
 106   return Incompatible;
 107 }
 108
 109 //===----------------------------------------------------------------------===//
 110 // AttributeListImpl Definition
 111 //===----------------------------------------------------------------------===//
 112
 113 namespace llvm {
 114   class AttributeListImpl;
 115 }
 116
 117 static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
 118
 119 namespace llvm {
 120 static ManagedStatic<sys::SmartMutex<true> > ALMutex;
 121
 122 class AttributeListImpl : public FoldingSetNode {
 123   sys::cas_flag RefCount;
 124
 125   // AttributesList is uniqued, these should not be publicly available.
 126   void operator=(const AttributeListImpl &); // Do not implement
 127   AttributeListImpl(const AttributeListImpl &); // Do not implement
 128   ~AttributeListImpl();                        // Private implementation
 129 public:
 130   SmallVector<AttributeWithIndex, 4> Attrs;
 131
 132   AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
 133     : Attrs(Attr, Attr+NumAttrs) {
 134     RefCount = 0;
 135   }
 136
 137   void AddRef() {
 138     sys::SmartScopedLock<true> Lock(*ALMutex);
 139     ++RefCount;
 140   }
 141   void DropRef() {
 142     sys::SmartScopedLock<true> Lock(*ALMutex);
 143     if (!AttributesLists.isConstructed())
 144       return;
 145     sys::cas_flag new_val = --RefCount;
 146     if (new_val == 0)
 147       delete this;
 148   }
 149
 150   void Profile(FoldingSetNodeID &ID) const {
 151     Profile(ID, Attrs.data(), Attrs.size());
 152   }
 153   static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
 154                       unsigned NumAttrs) {
 155     for (unsigned i = 0; i != NumAttrs; ++i)
 156       ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
 157   }
 158 };
 159 }
 160
 161 AttributeListImpl::~AttributeListImpl() {
 162   // NOTE: Lock must be acquired by caller.
 163   AttributesLists->RemoveNode(this);
 164 }
 165
 166
 167 AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
 168   // If there are no attributes then return a null AttributesList pointer.
 169   if (NumAttrs == 0)
 170     return AttrListPtr();
 171
 172 #ifndef NDEBUG
 173   for (unsigned i = 0; i != NumAttrs; ++i) {
 174     assert(Attrs[i].Attrs != Attribute::None &&
 175            "Pointless attribute!");
 176     assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
 177            "Misordered AttributesList!");
 178   }
 179 #endif
 180
 181   // Otherwise, build a key to look up the existing attributes.
 182   FoldingSetNodeID ID;
 183   AttributeListImpl::Profile(ID, Attrs, NumAttrs);
 184   void *InsertPos;
 185
 186   sys::SmartScopedLock<true> Lock(*ALMutex);
 187
 188   AttributeListImpl *PAL =
 189     AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
 190
 191   // If we didn't find any existing attributes of the same shape then
 192   // create a new one and insert it.
 193   if (!PAL) {
 194     PAL = new AttributeListImpl(Attrs, NumAttrs);
 195     AttributesLists->InsertNode(PAL, InsertPos);
 196   }
 197
 198   // Return the AttributesList that we found or created.
 199   return AttrListPtr(PAL);
 200 }
 201
 202
 203 //===----------------------------------------------------------------------===//
 204 // AttrListPtr Method Implementations
 205 //===----------------------------------------------------------------------===//
 206
 207 AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
 208   if (LI) LI->AddRef();
 209 }
 210
 211 AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
 212   if (AttrList) AttrList->AddRef();
 213 }
 214
 215 const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
 216   sys::SmartScopedLock<true> Lock(*ALMutex);
 217   if (AttrList == RHS.AttrList) return *this;
 218   if (AttrList) AttrList->DropRef();
 219   AttrList = RHS.AttrList;
 220   if (AttrList) AttrList->AddRef();
 221   return *this;
 222 }
 223
 224 AttrListPtr::~AttrListPtr() {
 225   if (AttrList) AttrList->DropRef();
 226 }
 227
 228 /// getNumSlots - Return the number of slots used in this attribute list.
 229 /// This is the number of arguments that have an attribute set on them
 230 /// (including the function itself).
 231 unsigned AttrListPtr::getNumSlots() const {
 232   return AttrList ? AttrList->Attrs.size() : 0;
 233 }
 234
 235 /// getSlot - Return the AttributeWithIndex at the specified slot.  This
 236 /// holds a number plus a set of attributes.
 237 const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
 238   assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
 239   return AttrList->Attrs[Slot];
 240 }
 241
 242
 243 /// getAttributes - The attributes for the specified index are
 244 /// returned.  Attributes for the result are denoted with Idx = 0.
 245 /// Function notes are denoted with idx = ~0.
 246 Attributes AttrListPtr::getAttributes(unsigned Idx) const {
 247   if (AttrList == 0) return Attribute::None;
 248
 249   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 250   for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
 251     if (Attrs[i].Index == Idx)
 252       return Attrs[i].Attrs;
 253   return Attribute::None;
 254 }
 255
 256 /// hasAttrSomewhere - Return true if the specified attribute is set for at
 257 /// least one parameter or for the return value.
 258 bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
 259   if (AttrList == 0) return false;
 260
 261   const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
 262   for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
 263     if (Attrs[i].Attrs & Attr)
 264       return true;
 265   return false;
 266 }
 267
 268
 269 AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
 270   Attributes OldAttrs = getAttributes(Idx);
 271 #ifndef NDEBUG
 272   // FIXME it is not obvious how this should work for alignment.
 273   // For now, say we can't change a known alignment.
 274   Attributes OldAlign = OldAttrs & Attribute::Alignment;
 275   Attributes NewAlign = Attrs & Attribute::Alignment;
 276   assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
 277          "Attempt to change alignment!");
 278 #endif
 279
 280   Attributes NewAttrs = OldAttrs | Attrs;
 281   if (NewAttrs == OldAttrs)
 282     return *this;
 283
 284   SmallVector<AttributeWithIndex, 8> NewAttrList;
 285   if (AttrList == 0)
 286     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 287   else {
 288     const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 289     unsigned i = 0, e = OldAttrList.size();
 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     if (i != e && OldAttrList[i].Index == Idx) {
 296       Attrs |= OldAttrList[i].Attrs;
 297       ++i;
 298     }
 299
 300     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 301
 302     // Copy attributes for arguments after this one.
 303     NewAttrList.insert(NewAttrList.end(),
 304                        OldAttrList.begin()+i, OldAttrList.end());
 305   }
 306
 307   return get(NewAttrList.data(), NewAttrList.size());
 308 }
 309
 310 AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
 311 #ifndef NDEBUG
 312   // FIXME it is not obvious how this should work for alignment.
 313   // For now, say we can't pass in alignment, which no current use does.
 314   assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
 315 #endif
 316   if (AttrList == 0) return AttrListPtr();
 317
 318   Attributes OldAttrs = getAttributes(Idx);
 319   Attributes NewAttrs = OldAttrs & ~Attrs;
 320   if (NewAttrs == OldAttrs)
 321     return *this;
 322
 323   SmallVector<AttributeWithIndex, 8> NewAttrList;
 324   const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
 325   unsigned i = 0, e = OldAttrList.size();
 326
 327   // Copy attributes for arguments before this one.
 328   for (; i != e && OldAttrList[i].Index < Idx; ++i)
 329     NewAttrList.push_back(OldAttrList[i]);
 330
 331   // If there are attributes already at this index, merge them in.
 332   assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
 333   Attrs = OldAttrList[i].Attrs & ~Attrs;
 334   ++i;
 335   if (Attrs)  // If any attributes left for this parameter, add them.
 336     NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
 337
 338   // Copy attributes for arguments after this one.
 339   NewAttrList.insert(NewAttrList.end(),
 340                      OldAttrList.begin()+i, OldAttrList.end());
 341
 342   return get(NewAttrList.data(), NewAttrList.size());
 343 }
 344
 345 void AttrListPtr::dump() const {
 346   dbgs() << "PAL[ ";
 347   for (unsigned i = 0; i < getNumSlots(); ++i) {
 348     const AttributeWithIndex &PAWI = getSlot(i);
 349     dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
 350   }
 351
 352   dbgs() << "]\n";
 353 }