Attributes.cpp revision e642658480ed0c9cde023a165edca237ba90bd31 
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/Streams.h"
19#include "llvm/Support/ManagedStatic.h"
20using namespace llvm;
21
22//===----------------------------------------------------------------------===//
23// Attribute Function Definitions
24//===----------------------------------------------------------------------===//
25
26std::string Attribute::getAsString(Attributes Attrs) {
27  std::string Result;
28  if (Attrs & Attribute::ZExt)
29    Result += "zeroext ";
30  if (Attrs & Attribute::SExt)
31    Result += "signext ";
32  if (Attrs & Attribute::NoReturn)
33    Result += "noreturn ";
34  if (Attrs & Attribute::NoUnwind)
35    Result += "nounwind ";
36  if (Attrs & Attribute::InReg)
37    Result += "inreg ";
38  if (Attrs & Attribute::NoAlias)
39    Result += "noalias ";
40  if (Attrs & Attribute::NoCapture)
41    Result += "nocapture ";
42  if (Attrs & Attribute::StructRet)
43    Result += "sret ";
44  if (Attrs & Attribute::ByVal)
45    Result += "byval ";
46  if (Attrs & Attribute::Nest)
47    Result += "nest ";
48  if (Attrs & Attribute::ReadNone)
49    Result += "readnone ";
50  if (Attrs & Attribute::ReadOnly)
51    Result += "readonly ";
52  if (Attrs & Attribute::OptimizeForSize)
53    Result += "optsize ";
54  if (Attrs & Attribute::NoInline)
55    Result += "noinline ";
56  if (Attrs & Attribute::AlwaysInline)
57    Result += "alwaysinline ";
58  if (Attrs & Attribute::StackProtect)
59    Result += "ssp ";
60  if (Attrs & Attribute::StackProtectReq)
61    Result += "sspreq ";
62  if (Attrs & Attribute::Alignment) {
63    Result += "align ";
64    Result += utostr(1ull << ((Attrs & Attribute::Alignment)>>16));
65    Result += " ";
66  }
67  // Trim the trailing space.
68  assert(!Result.empty() && "Unknown attribute!");
69  Result.erase(Result.end()-1);
70  return Result;
71}
72
73Attributes Attribute::typeIncompatible(const Type *Ty) {
74  Attributes Incompatible = None;
75
76  if (!Ty->isInteger())
77    // Attributes that only apply to integers.
78    Incompatible |= SExt | ZExt;
79
80  if (!isa<PointerType>(Ty))
81    // Attributes that only apply to pointers.
82    Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
83
84  return Incompatible;
85}
86
87//===----------------------------------------------------------------------===//
88// AttributeListImpl Definition
89//===----------------------------------------------------------------------===//
90
91namespace llvm {
92class AttributeListImpl : public FoldingSetNode {
93  unsigned RefCount;
94
95  // AttributesList is uniqued, these should not be publicly available.
96  void operator=(const AttributeListImpl &); // Do not implement
97  AttributeListImpl(const AttributeListImpl &); // Do not implement
98  ~AttributeListImpl();                        // Private implementation
99public:
100  SmallVector<AttributeWithIndex, 4> Attrs;
101
102  AttributeListImpl(const AttributeWithIndex *Attr, unsigned NumAttrs)
103    : Attrs(Attr, Attr+NumAttrs) {
104    RefCount = 0;
105  }
106
107  void AddRef() { ++RefCount; }
108  void DropRef() { if (--RefCount == 0) delete this; }
109
110  void Profile(FoldingSetNodeID &ID) const {
111    Profile(ID, &Attrs[0], Attrs.size());
112  }
113  static void Profile(FoldingSetNodeID &ID, const AttributeWithIndex *Attr,
114                      unsigned NumAttrs) {
115    for (unsigned i = 0; i != NumAttrs; ++i)
116      ID.AddInteger(uint64_t(Attr[i].Attrs) << 32 | unsigned(Attr[i].Index));
117  }
118};
119}
120
121static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
122
123AttributeListImpl::~AttributeListImpl() {
124  AttributesLists->RemoveNode(this);
125}
126
127
128AttrListPtr AttrListPtr::get(const AttributeWithIndex *Attrs, unsigned NumAttrs) {
129  // If there are no attributes then return a null AttributesList pointer.
130  if (NumAttrs == 0)
131    return AttrListPtr();
132
133#ifndef NDEBUG
134  for (unsigned i = 0; i != NumAttrs; ++i) {
135    assert(Attrs[i].Attrs != Attribute::None &&
136           "Pointless attribute!");
137    assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
138           "Misordered AttributesList!");
139  }
140#endif
141
142  // Otherwise, build a key to look up the existing attributes.
143  FoldingSetNodeID ID;
144  AttributeListImpl::Profile(ID, Attrs, NumAttrs);
145  void *InsertPos;
146  AttributeListImpl *PAL =
147    AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
148
149  // If we didn't find any existing attributes of the same shape then
150  // create a new one and insert it.
151  if (!PAL) {
152    PAL = new AttributeListImpl(Attrs, NumAttrs);
153    AttributesLists->InsertNode(PAL, InsertPos);
154  }
155
156  // Return the AttributesList that we found or created.
157  return AttrListPtr(PAL);
158}
159
160
161//===----------------------------------------------------------------------===//
162// AttrListPtr Method Implementations
163//===----------------------------------------------------------------------===//
164
165AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
166  if (LI) LI->AddRef();
167}
168
169AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
170  if (AttrList) AttrList->AddRef();
171}
172
173const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
174  if (AttrList == RHS.AttrList) return *this;
175  if (AttrList) AttrList->DropRef();
176  AttrList = RHS.AttrList;
177  if (AttrList) AttrList->AddRef();
178  return *this;
179}
180
181AttrListPtr::~AttrListPtr() {
182  if (AttrList) AttrList->DropRef();
183}
184
185/// getNumSlots - Return the number of slots used in this attribute list.
186/// This is the number of arguments that have an attribute set on them
187/// (including the function itself).
188unsigned AttrListPtr::getNumSlots() const {
189  return AttrList ? AttrList->Attrs.size() : 0;
190}
191
192/// getSlot - Return the AttributeWithIndex at the specified slot.  This
193/// holds a number plus a set of attributes.
194const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
195  assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
196  return AttrList->Attrs[Slot];
197}
198
199
200/// getAttributes - The attributes for the specified index are
201/// returned.  Attributes for the result are denoted with Idx = 0.
202/// Function notes are denoted with idx = ~0.
203Attributes AttrListPtr::getAttributes(unsigned Idx) const {
204  if (AttrList == 0) return Attribute::None;
205
206  const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
207  for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
208    if (Attrs[i].Index == Idx)
209      return Attrs[i].Attrs;
210  return Attribute::None;
211}
212
213/// hasAttrSomewhere - Return true if the specified attribute is set for at
214/// least one parameter or for the return value.
215bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
216  if (AttrList == 0) return false;
217
218  const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
219  for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
220    if (Attrs[i].Attrs & Attr)
221      return true;
222  return false;
223}
224
225
226AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
227  Attributes OldAttrs = getAttributes(Idx);
228#ifndef NDEBUG
229  // FIXME it is not obvious how this should work for alignment.
230  // For now, say we can't change a known alignment.
231  Attributes OldAlign = OldAttrs & Attribute::Alignment;
232  Attributes NewAlign = Attrs & Attribute::Alignment;
233  assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
234         "Attempt to change alignment!");
235#endif
236
237  Attributes NewAttrs = OldAttrs | Attrs;
238  if (NewAttrs == OldAttrs)
239    return *this;
240
241  SmallVector<AttributeWithIndex, 8> NewAttrList;
242  if (AttrList == 0)
243    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
244  else {
245    const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
246    unsigned i = 0, e = OldAttrList.size();
247    // Copy attributes for arguments before this one.
248    for (; i != e && OldAttrList[i].Index < Idx; ++i)
249      NewAttrList.push_back(OldAttrList[i]);
250
251    // If there are attributes already at this index, merge them in.
252    if (i != e && OldAttrList[i].Index == Idx) {
253      Attrs |= OldAttrList[i].Attrs;
254      ++i;
255    }
256
257    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
258
259    // Copy attributes for arguments after this one.
260    NewAttrList.insert(NewAttrList.end(),
261                       OldAttrList.begin()+i, OldAttrList.end());
262  }
263
264  return get(&NewAttrList[0], NewAttrList.size());
265}
266
267AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
268#ifndef NDEBUG
269  // FIXME it is not obvious how this should work for alignment.
270  // For now, say we can't pass in alignment, which no current use does.
271  assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
272#endif
273  if (AttrList == 0) return AttrListPtr();
274
275  Attributes OldAttrs = getAttributes(Idx);
276  Attributes NewAttrs = OldAttrs & ~Attrs;
277  if (NewAttrs == OldAttrs)
278    return *this;
279
280  SmallVector<AttributeWithIndex, 8> NewAttrList;
281  const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
282  unsigned i = 0, e = OldAttrList.size();
283
284  // Copy attributes for arguments before this one.
285  for (; i != e && OldAttrList[i].Index < Idx; ++i)
286    NewAttrList.push_back(OldAttrList[i]);
287
288  // If there are attributes already at this index, merge them in.
289  assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
290  Attrs = OldAttrList[i].Attrs & ~Attrs;
291  ++i;
292  if (Attrs)  // If any attributes left for this parameter, add them.
293    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
294
295  // Copy attributes for arguments after this one.
296  NewAttrList.insert(NewAttrList.end(),
297                     OldAttrList.begin()+i, OldAttrList.end());
298
299  return get(&NewAttrList[0], NewAttrList.size());
300}
301
302void AttrListPtr::dump() const {
303  cerr << "PAL[ ";
304  for (unsigned i = 0; i < getNumSlots(); ++i) {
305    const AttributeWithIndex &PAWI = getSlot(i);
306    cerr << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
307  }
308
309  cerr << "]\n";
310}
311