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"
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::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::AddressSafety)
80    Result += "address_safety ";
81  if (Attrs & Attribute::StackAlignment) {
82    Result += "alignstack(";
83    Result += utostr(Attribute::getStackAlignmentFromAttrs(Attrs));
84    Result += ") ";
85  }
86  if (Attrs & Attribute::Alignment) {
87    Result += "align ";
88    Result += utostr(Attribute::getAlignmentFromAttrs(Attrs));
89    Result += " ";
90  }
91  // Trim the trailing space.
92  assert(!Result.empty() && "Unknown attribute!");
93  Result.erase(Result.end()-1);
94  return Result;
95}
96
97Attributes Attribute::typeIncompatible(Type *Ty) {
98  Attributes Incompatible = None;
99
100  if (!Ty->isIntegerTy())
101    // Attributes that only apply to integers.
102    Incompatible |= SExt | ZExt;
103
104  if (!Ty->isPointerTy())
105    // Attributes that only apply to pointers.
106    Incompatible |= ByVal | Nest | NoAlias | StructRet | NoCapture;
107
108  return Incompatible;
109}
110
111//===----------------------------------------------------------------------===//
112// AttributeListImpl Definition
113//===----------------------------------------------------------------------===//
114
115namespace llvm {
116  class AttributeListImpl;
117}
118
119static ManagedStatic<FoldingSet<AttributeListImpl> > AttributesLists;
120
121namespace llvm {
122static ManagedStatic<sys::SmartMutex<true> > ALMutex;
123
124class AttributeListImpl : public FoldingSetNode {
125  sys::cas_flag RefCount;
126
127  // AttributesList is uniqued, these should not be publicly available.
128  void operator=(const AttributeListImpl &); // Do not implement
129  AttributeListImpl(const AttributeListImpl &); // Do not implement
130  ~AttributeListImpl();                        // Private implementation
131public:
132  SmallVector<AttributeWithIndex, 4> Attrs;
133
134  AttributeListImpl(ArrayRef<AttributeWithIndex> attrs)
135    : Attrs(attrs.begin(), attrs.end()) {
136    RefCount = 0;
137  }
138
139  void AddRef() {
140    sys::SmartScopedLock<true> Lock(*ALMutex);
141    ++RefCount;
142  }
143  void DropRef() {
144    sys::SmartScopedLock<true> Lock(*ALMutex);
145    if (!AttributesLists.isConstructed())
146      return;
147    sys::cas_flag new_val = --RefCount;
148    if (new_val == 0)
149      delete this;
150  }
151
152  void Profile(FoldingSetNodeID &ID) const {
153    Profile(ID, Attrs);
154  }
155  static void Profile(FoldingSetNodeID &ID, ArrayRef<AttributeWithIndex> Attrs){
156    for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
157      ID.AddInteger(Attrs[i].Attrs.Raw());
158      ID.AddInteger(Attrs[i].Index);
159    }
160  }
161};
162}
163
164AttributeListImpl::~AttributeListImpl() {
165  // NOTE: Lock must be acquired by caller.
166  AttributesLists->RemoveNode(this);
167}
168
169
170AttrListPtr AttrListPtr::get(ArrayRef<AttributeWithIndex> Attrs) {
171  // If there are no attributes then return a null AttributesList pointer.
172  if (Attrs.empty())
173    return AttrListPtr();
174
175#ifndef NDEBUG
176  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
177    assert(Attrs[i].Attrs != Attribute::None &&
178           "Pointless attribute!");
179    assert((!i || Attrs[i-1].Index < Attrs[i].Index) &&
180           "Misordered AttributesList!");
181  }
182#endif
183
184  // Otherwise, build a key to look up the existing attributes.
185  FoldingSetNodeID ID;
186  AttributeListImpl::Profile(ID, Attrs);
187  void *InsertPos;
188
189  sys::SmartScopedLock<true> Lock(*ALMutex);
190
191  AttributeListImpl *PAL =
192    AttributesLists->FindNodeOrInsertPos(ID, InsertPos);
193
194  // If we didn't find any existing attributes of the same shape then
195  // create a new one and insert it.
196  if (!PAL) {
197    PAL = new AttributeListImpl(Attrs);
198    AttributesLists->InsertNode(PAL, InsertPos);
199  }
200
201  // Return the AttributesList that we found or created.
202  return AttrListPtr(PAL);
203}
204
205
206//===----------------------------------------------------------------------===//
207// AttrListPtr Method Implementations
208//===----------------------------------------------------------------------===//
209
210AttrListPtr::AttrListPtr(AttributeListImpl *LI) : AttrList(LI) {
211  if (LI) LI->AddRef();
212}
213
214AttrListPtr::AttrListPtr(const AttrListPtr &P) : AttrList(P.AttrList) {
215  if (AttrList) AttrList->AddRef();
216}
217
218const AttrListPtr &AttrListPtr::operator=(const AttrListPtr &RHS) {
219  sys::SmartScopedLock<true> Lock(*ALMutex);
220  if (AttrList == RHS.AttrList) return *this;
221  if (AttrList) AttrList->DropRef();
222  AttrList = RHS.AttrList;
223  if (AttrList) AttrList->AddRef();
224  return *this;
225}
226
227AttrListPtr::~AttrListPtr() {
228  if (AttrList) AttrList->DropRef();
229}
230
231/// getNumSlots - Return the number of slots used in this attribute list.
232/// This is the number of arguments that have an attribute set on them
233/// (including the function itself).
234unsigned AttrListPtr::getNumSlots() const {
235  return AttrList ? AttrList->Attrs.size() : 0;
236}
237
238/// getSlot - Return the AttributeWithIndex at the specified slot.  This
239/// holds a number plus a set of attributes.
240const AttributeWithIndex &AttrListPtr::getSlot(unsigned Slot) const {
241  assert(AttrList && Slot < AttrList->Attrs.size() && "Slot # out of range!");
242  return AttrList->Attrs[Slot];
243}
244
245
246/// getAttributes - The attributes for the specified index are
247/// returned.  Attributes for the result are denoted with Idx = 0.
248/// Function notes are denoted with idx = ~0.
249Attributes AttrListPtr::getAttributes(unsigned Idx) const {
250  if (AttrList == 0) return Attribute::None;
251
252  const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
253  for (unsigned i = 0, e = Attrs.size(); i != e && Attrs[i].Index <= Idx; ++i)
254    if (Attrs[i].Index == Idx)
255      return Attrs[i].Attrs;
256  return Attribute::None;
257}
258
259/// hasAttrSomewhere - Return true if the specified attribute is set for at
260/// least one parameter or for the return value.
261bool AttrListPtr::hasAttrSomewhere(Attributes Attr) const {
262  if (AttrList == 0) return false;
263
264  const SmallVector<AttributeWithIndex, 4> &Attrs = AttrList->Attrs;
265  for (unsigned i = 0, e = Attrs.size(); i != e; ++i)
266    if (Attrs[i].Attrs & Attr)
267      return true;
268  return false;
269}
270
271
272AttrListPtr AttrListPtr::addAttr(unsigned Idx, Attributes Attrs) const {
273  Attributes OldAttrs = getAttributes(Idx);
274#ifndef NDEBUG
275  // FIXME it is not obvious how this should work for alignment.
276  // For now, say we can't change a known alignment.
277  Attributes OldAlign = OldAttrs & Attribute::Alignment;
278  Attributes NewAlign = Attrs & Attribute::Alignment;
279  assert((!OldAlign || !NewAlign || OldAlign == NewAlign) &&
280         "Attempt to change alignment!");
281#endif
282
283  Attributes NewAttrs = OldAttrs | Attrs;
284  if (NewAttrs == OldAttrs)
285    return *this;
286
287  SmallVector<AttributeWithIndex, 8> NewAttrList;
288  if (AttrList == 0)
289    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
290  else {
291    const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
292    unsigned i = 0, e = OldAttrList.size();
293    // Copy attributes for arguments before this one.
294    for (; i != e && OldAttrList[i].Index < Idx; ++i)
295      NewAttrList.push_back(OldAttrList[i]);
296
297    // If there are attributes already at this index, merge them in.
298    if (i != e && OldAttrList[i].Index == Idx) {
299      Attrs |= OldAttrList[i].Attrs;
300      ++i;
301    }
302
303    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
304
305    // Copy attributes for arguments after this one.
306    NewAttrList.insert(NewAttrList.end(),
307                       OldAttrList.begin()+i, OldAttrList.end());
308  }
309
310  return get(NewAttrList);
311}
312
313AttrListPtr AttrListPtr::removeAttr(unsigned Idx, Attributes Attrs) const {
314#ifndef NDEBUG
315  // FIXME it is not obvious how this should work for alignment.
316  // For now, say we can't pass in alignment, which no current use does.
317  assert(!(Attrs & Attribute::Alignment) && "Attempt to exclude alignment!");
318#endif
319  if (AttrList == 0) return AttrListPtr();
320
321  Attributes OldAttrs = getAttributes(Idx);
322  Attributes NewAttrs = OldAttrs & ~Attrs;
323  if (NewAttrs == OldAttrs)
324    return *this;
325
326  SmallVector<AttributeWithIndex, 8> NewAttrList;
327  const SmallVector<AttributeWithIndex, 4> &OldAttrList = AttrList->Attrs;
328  unsigned i = 0, e = OldAttrList.size();
329
330  // Copy attributes for arguments before this one.
331  for (; i != e && OldAttrList[i].Index < Idx; ++i)
332    NewAttrList.push_back(OldAttrList[i]);
333
334  // If there are attributes already at this index, merge them in.
335  assert(OldAttrList[i].Index == Idx && "Attribute isn't set?");
336  Attrs = OldAttrList[i].Attrs & ~Attrs;
337  ++i;
338  if (Attrs)  // If any attributes left for this parameter, add them.
339    NewAttrList.push_back(AttributeWithIndex::get(Idx, Attrs));
340
341  // Copy attributes for arguments after this one.
342  NewAttrList.insert(NewAttrList.end(),
343                     OldAttrList.begin()+i, OldAttrList.end());
344
345  return get(NewAttrList);
346}
347
348void AttrListPtr::dump() const {
349  dbgs() << "PAL[ ";
350  for (unsigned i = 0; i < getNumSlots(); ++i) {
351    const AttributeWithIndex &PAWI = getSlot(i);
352    dbgs() << "{" << PAWI.Index << "," << PAWI.Attrs << "} ";
353  }
354
355  dbgs() << "]\n";
356}
357