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::ReturnsTwice) 42 Result += "returns_twice "; 43 if (Attrs & Attribute::InReg) 44 Result += "inreg "; 45 if (Attrs & Attribute::NoAlias) 46 Result += "noalias "; 47 if (Attrs & Attribute::NoCapture) 48 Result += "nocapture "; 49 if (Attrs & Attribute::StructRet) 50 Result += "sret "; 51 if (Attrs & Attribute::ByVal) 52 Result += "byval "; 53 if (Attrs & Attribute::Nest) 54 Result += "nest "; 55 if (Attrs & Attribute::ReadNone) 56 Result += "readnone "; 57 if (Attrs & Attribute::ReadOnly) 58 Result += "readonly "; 59 if (Attrs & Attribute::OptimizeForSize) 60 Result += "optsize "; 61 if (Attrs & Attribute::NoInline) 62 Result += "noinline "; 63 if (Attrs & Attribute::InlineHint) 64 Result += "inlinehint "; 65 if (Attrs & Attribute::AlwaysInline) 66 Result += "alwaysinline "; 67 if (Attrs & Attribute::StackProtect) 68 Result += "ssp "; 69 if (Attrs & Attribute::StackProtectReq) 70 Result += "sspreq "; 71 if (Attrs & Attribute::NoRedZone) 72 Result += "noredzone "; 73 if (Attrs & Attribute::NoImplicitFloat) 74 Result += "noimplicitfloat "; 75 if (Attrs & Attribute::Naked) 76 Result += "naked "; 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(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 } 354
