Attributes.cpp revision cb86def1c2084f2b1c72fd04e5384d472e7cf3a0
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" 23using namespace llvm; 24 25//===----------------------------------------------------------------------===// 26// Attribute Function Definitions 27//===----------------------------------------------------------------------===// 28 29std::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::StackAlignment) { 74 Result += "alignstack("; 75 Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs)); 76 Result += ") "; 77 } 78 if (Attrs & Attribute::Alignment) { 79 Result += "align "; 80 Result += utostr(Attribute::getAlignmentFromAttrs(Attrs)); 81 Result += " "; 82 } 83 // Trim the trailing space. 84 assert(!Result.empty() && "Unknown attribute!"); 85 Result.erase(Result.end()-1); 86 return Result; 87} 88 89Attributes Attribute::typeIncompatible(const Type *Ty) { 90 Attributes Incompatible = None; 91 92 if (!Ty->isIntegerTy()) 93 // Attributes that only apply to integers. 94 Incompatible |= SExt | ZExt; 95 96 if (!Ty->isPointerTy()) 97 // Attributes that only apply to pointers. 98 Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture; 99 100 return Incompatible; 101} 102 103//===----------------------------------------------------------------------===// 104// AttributeListImpl Definition 105//===----------------------------------------------------------------------===// 106 107namespace llvm { 108class AttributeListImpl : public FoldingSetNode { 109 sys::cas_flag RefCount; 110 111 // AttributesList is uniqued, these should not be publicly available. 112 void operator=(const AttributeListImpl &); // Do not implement 113 AttributeListImpl(const AttributeListImpl &); // Do not implement 114 ~AttributeListImpl(); // Private implementation 115public: 116 SmallVector<AttributeWithIndex, 4> Attrs; 117 118 AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs) 119 : Attrs(Attr, Attr+NumAttrs) { 120 RefCount = 0; 121 } 122 123 void AddRef() { sys::AtomicIncrement(&RefCount); } 124 void DropRef() { 125 sys::cas_flag old = sys::AtomicDecrement(&RefCount); 126 if (old == 0) delete this; 127 } 128 129 void Profile(FoldingSetNodeID &ID) const { 130 Profile(ID, Attrs.data(), Attrs.size()); 131 } 132 static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr, 133 unsigned NumAttrs) { 134 for (unsigned i = 0; i != NumAttrs; ++i) 135 ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index)); 136 } 137}; 138} 139 140static ManagedStatic<sys::SmartMutex<true> > ALMutex; 141static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists; 142 143AttributeListImpl::~AttributeListImpl() { 144 sys::SmartScopedLock<true> Lock(*ALMutex); 145 AttributesLists->RemoveNode(this); 146} 147 148 149AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) { 150 // If there are no attributes then return a null AttributesList pointer. 151 if (NumAttrs == 0) 152 return AttrListPtr(); 153 154#ifndef NDEBUG 155 for (unsigned i = 0; i != NumAttrs; ++i) { 156 assert(Attrs[i].Attrs != Attribute::None && 157 "Pointless attribute!"); 158 assert((!i || Attrs[i-1].Index < Attrs[i].Index) && 159 "Misordered AttributesList!"); 160 } 161#endif 162 163 // Otherwise, build a key to look up the existing attributes. 164 FoldingSetNodeID ID; 165 AttributeListImpl::Profile(ID, Attrs, NumAttrs); 166 void *InsertPos; 167 168 sys::SmartScopedLock<true> Lock(*ALMutex); 169 170 AttributeListImpl *PAL = 171 AttributesLists->FindNodeOrInsertPos(ID, InsertPos); 172 173 // If we didn't find any existing attributes of the same shape then 174 // create a new one and insert it. 175 if (!PAL) { 176 PAL = new AttributeListImpl(Attrs, NumAttrs); 177 AttributesLists->InsertNode(PAL, InsertPos); 178 } 179 180 // Return the AttributesList that we found or created. 181 return AttrListPtr(PAL); 182} 183 184 185//===----------------------------------------------------------------------===// 186// AttrListPtr Method Implementations 187//===----------------------------------------------------------------------===// 188 189AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) { 190 if (LI) LI->AddRef(); 191} 192 193AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) { 194 if (AttrList) AttrList->AddRef(); 195} 196 197const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) { 198 sys::SmartScopedLock<true> Lock(*ALMutex); 199 if (AttrList == RHS.AttrList) return *this; 200 if (AttrList) AttrList->DropRef(); 201 AttrList = RHS.AttrList; 202 if (AttrList) AttrList->AddRef(); 203 return *this; 204} 205 206AttrListPtr::~AttrListPtr() { 207 if (AttrList) AttrList->DropRef(); 208} 209 210/// getNumSlots - Return the number of slots used in this attribute list. 211/// This is the number of arguments that have an attribute set on them 212/// (including the function itself). 213unsigned AttrListPtr::getNumSlots() const { 214 return AttrList ? AttrList->Attrs.size() : 0; 215} 216 217/// getSlot - Return the AttributeWithIndex at the specified slot. This 218/// holds a number plus a set of attributes. 219const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const { 220 assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!"); 221 return AttrList->Attrs[Slot]; 222} 223 224 225/// getAttributes - The attributes for the specified index are 226/// returned. Attributes for the result are denoted with Idx = 0. 227/// Function notes are denoted with idx = ~0. 228Attributes AttrListPtr::getAttributes(unsigned Idx) const { 229 if (AttrList == 0) return Attribute::None; 230 231 const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs; 232 for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i) 233 if (Attrs[i].Index == Idx) 234 return Attrs[i].Attrs; 235 return Attribute::None; 236} 237 238/// hasAttrSomewhere - Return true if the specified attribute is set for at 239/// least one parameter or for the return value. 240bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const { 241 if (AttrList == 0) return false; 242 243 const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs; 244 for (unsigned i = 0, e = Attrs.size(); i != e; ++i) 245 if (Attrs[i].Attrs & Attr) 246 return true; 247 return false; 248} 249 250 251AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const { 252 Attributes OldAttrs = getAttributes(Idx); 253#ifndef NDEBUG 254 // FIXME it is not obvious how this should work for alignment. 255 // For now, say we can't change a known alignment. 256 Attributes OldAlign = OldAttrs & Attribute::Alignment; 257 Attributes NewAlign = Attrs & Attribute::Alignment; 258 assert((!OldAlign || !NewAlign || OldAlign == NewAlign) && 259 "Attempt to change alignment!"); 260#endif 261 262 Attributes NewAttrs = OldAttrs | Attrs; 263 if (NewAttrs == OldAttrs) 264 return *this; 265 266 SmallVector<AttributeWithIndex, 8> NewAttrList; 267 if (AttrList == 0) 268 NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs)); 269 else { 270 const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs; 271 unsigned i = 0, e = OldAttrList.size(); 272 // Copy attributes for arguments before this one. 273 for (; i != e && OldAttrList[i].Index < Idx; ++i) 274 NewAttrList.push_back(OldAttrList[i]); 275 276 // If there are attributes already at this index, merge them in. 277 if (i != e && OldAttrList[i].Index == Idx) { 278 Attrs |= OldAttrList[i].Attrs; 279 ++i; 280 } 281 282 NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs)); 283 284 // Copy attributes for arguments after this one. 285 NewAttrList.insert(NewAttrList.end(), 286 OldAttrList.begin()+i, OldAttrList.end()); 287 } 288 289 return get(NewAttrList.data(), NewAttrList.size()); 290} 291 292AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const { 293#ifndef NDEBUG 294 // FIXME it is not obvious how this should work for alignment. 295 // For now, say we can't pass in alignment, which no current use does. 296 assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!"); 297#endif 298 if (AttrList == 0) return AttrListPtr(); 299 300 Attributes OldAttrs = getAttributes(Idx); 301 Attributes NewAttrs = OldAttrs & ~Attrs; 302 if (NewAttrs == OldAttrs) 303 return *this; 304 305 SmallVector<AttributeWithIndex, 8> NewAttrList; 306 const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs; 307 unsigned i = 0, e = OldAttrList.size(); 308 309 // Copy attributes for arguments before this one. 310 for (; i != e && OldAttrList[i].Index < Idx; ++i) 311 NewAttrList.push_back(OldAttrList[i]); 312 313 // If there are attributes already at this index, merge them in. 314 assert(OldAttrList[i].Index == Idx && "Attribute isn't set?"); 315 Attrs = OldAttrList[i].Attrs & ~Attrs; 316 ++i; 317 if (Attrs) // If any attributes left for this parameter, add them. 318 NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs)); 319 320 // Copy attributes for arguments after this one. 321 NewAttrList.insert(NewAttrList.end(), 322 OldAttrList.begin()+i, OldAttrList.end()); 323 324 return get(NewAttrList.data(), NewAttrList.size()); 325} 326 327void AttrListPtr::dump() const { 328 dbgs() << "PAL[ "; 329 for (unsigned i = 0; i < getNumSlots(); ++i) { 330 const AttributeWithIndex &PAWI = getSlot(i); 331 dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} "; 332 } 333 334 dbgs() << "]\n"; 335} 336