1//===-- AttributeImpl.h - Attribute Internals -------------------*- C++ -*-===//
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/// \file
11/// \brief This file defines various helper methods and classes used by
12/// LLVMContextImpl for creating and managing attributes.
13///
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_LIB_IR_ATTRIBUTEIMPL_H
17#define LLVM_LIB_IR_ATTRIBUTEIMPL_H
18
19#include "llvm/ADT/FoldingSet.h"
20#include "llvm/ADT/Optional.h"
21#include "llvm/IR/Attributes.h"
22#include "llvm/Support/DataTypes.h"
23#include "llvm/Support/TrailingObjects.h"
24#include <climits>
25#include <string>
26
27namespace llvm {
28
29class Constant;
30class LLVMContext;
31
32//===----------------------------------------------------------------------===//
33/// \class
34/// \brief This class represents a single, uniqued attribute. That attribute
35/// could be a single enum, a tuple, or a string.
36class AttributeImpl : public FoldingSetNode {
37  unsigned char KindID; ///< Holds the AttrEntryKind of the attribute
38
39  // AttributesImpl is uniqued, these should not be publicly available.
40  void operator=(const AttributeImpl &) = delete;
41  AttributeImpl(const AttributeImpl &) = delete;
42
43protected:
44  enum AttrEntryKind {
45    EnumAttrEntry,
46    IntAttrEntry,
47    StringAttrEntry
48  };
49
50  AttributeImpl(AttrEntryKind KindID) : KindID(KindID) {}
51
52public:
53  virtual ~AttributeImpl();
54
55  bool isEnumAttribute() const { return KindID == EnumAttrEntry; }
56  bool isIntAttribute() const { return KindID == IntAttrEntry; }
57  bool isStringAttribute() const { return KindID == StringAttrEntry; }
58
59  bool hasAttribute(Attribute::AttrKind A) const;
60  bool hasAttribute(StringRef Kind) const;
61
62  Attribute::AttrKind getKindAsEnum() const;
63  uint64_t getValueAsInt() const;
64
65  StringRef getKindAsString() const;
66  StringRef getValueAsString() const;
67
68  /// \brief Used when sorting the attributes.
69  bool operator<(const AttributeImpl &AI) const;
70
71  void Profile(FoldingSetNodeID &ID) const {
72    if (isEnumAttribute())
73      Profile(ID, getKindAsEnum(), 0);
74    else if (isIntAttribute())
75      Profile(ID, getKindAsEnum(), getValueAsInt());
76    else
77      Profile(ID, getKindAsString(), getValueAsString());
78  }
79  static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
80                      uint64_t Val) {
81    ID.AddInteger(Kind);
82    if (Val) ID.AddInteger(Val);
83  }
84  static void Profile(FoldingSetNodeID &ID, StringRef Kind, StringRef Values) {
85    ID.AddString(Kind);
86    if (!Values.empty()) ID.AddString(Values);
87  }
88
89  // FIXME: Remove this!
90  static uint64_t getAttrMask(Attribute::AttrKind Val);
91};
92
93//===----------------------------------------------------------------------===//
94/// \class
95/// \brief A set of classes that contain the value of the
96/// attribute object. There are three main categories: enum attribute entries,
97/// represented by Attribute::AttrKind; alignment attribute entries; and string
98/// attribute enties, which are for target-dependent attributes.
99
100class EnumAttributeImpl : public AttributeImpl {
101  virtual void anchor();
102  Attribute::AttrKind Kind;
103
104protected:
105  EnumAttributeImpl(AttrEntryKind ID, Attribute::AttrKind Kind)
106      : AttributeImpl(ID), Kind(Kind) {}
107
108public:
109  EnumAttributeImpl(Attribute::AttrKind Kind)
110      : AttributeImpl(EnumAttrEntry), Kind(Kind) {}
111
112  Attribute::AttrKind getEnumKind() const { return Kind; }
113};
114
115class IntAttributeImpl : public EnumAttributeImpl {
116  void anchor() override;
117  uint64_t Val;
118
119public:
120  IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val)
121      : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
122    assert((Kind == Attribute::Alignment || Kind == Attribute::StackAlignment ||
123            Kind == Attribute::Dereferenceable ||
124            Kind == Attribute::DereferenceableOrNull ||
125            Kind == Attribute::AllocSize) &&
126           "Wrong kind for int attribute!");
127  }
128
129  uint64_t getValue() const { return Val; }
130};
131
132class StringAttributeImpl : public AttributeImpl {
133  virtual void anchor();
134  std::string Kind;
135  std::string Val;
136
137public:
138  StringAttributeImpl(StringRef Kind, StringRef Val = StringRef())
139      : AttributeImpl(StringAttrEntry), Kind(Kind), Val(Val) {}
140
141  StringRef getStringKind() const { return Kind; }
142  StringRef getStringValue() const { return Val; }
143};
144
145//===----------------------------------------------------------------------===//
146/// \class
147/// \brief This class represents a group of attributes that apply to one
148/// element: function, return type, or parameter.
149class AttributeSetNode final
150    : public FoldingSetNode,
151      private TrailingObjects<AttributeSetNode, Attribute> {
152  friend TrailingObjects;
153
154  unsigned NumAttrs; ///< Number of attributes in this node.
155  /// Bitset with a bit for each available attribute Attribute::AttrKind.
156  uint64_t AvailableAttrs;
157
158  AttributeSetNode(ArrayRef<Attribute> Attrs)
159    : NumAttrs(Attrs.size()), AvailableAttrs(0) {
160    static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
161                  "Too many attributes for AvailableAttrs");
162    // There's memory after the node where we can store the entries in.
163    std::copy(Attrs.begin(), Attrs.end(), getTrailingObjects<Attribute>());
164
165    for (Attribute I : *this) {
166      if (!I.isStringAttribute()) {
167        AvailableAttrs |= ((uint64_t)1) << I.getKindAsEnum();
168      }
169    }
170  }
171
172  // AttributesSetNode is uniqued, these should not be publicly available.
173  void operator=(const AttributeSetNode &) = delete;
174  AttributeSetNode(const AttributeSetNode &) = delete;
175public:
176  void operator delete(void *p) { ::operator delete(p); }
177
178  static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
179
180  /// \brief Return the number of attributes this AttributeSet contains.
181  unsigned getNumAttributes() const { return NumAttrs; }
182
183  bool hasAttribute(Attribute::AttrKind Kind) const {
184    return AvailableAttrs & ((uint64_t)1) << Kind;
185  }
186  bool hasAttribute(StringRef Kind) const;
187  bool hasAttributes() const { return NumAttrs != 0; }
188
189  Attribute getAttribute(Attribute::AttrKind Kind) const;
190  Attribute getAttribute(StringRef Kind) const;
191
192  unsigned getAlignment() const;
193  unsigned getStackAlignment() const;
194  uint64_t getDereferenceableBytes() const;
195  uint64_t getDereferenceableOrNullBytes() const;
196  std::pair<unsigned, Optional<unsigned>> getAllocSizeArgs() const;
197  std::string getAsString(bool InAttrGrp) const;
198
199  typedef const Attribute *iterator;
200  iterator begin() const { return getTrailingObjects<Attribute>(); }
201  iterator end() const { return begin() + NumAttrs; }
202
203  void Profile(FoldingSetNodeID &ID) const {
204    Profile(ID, makeArrayRef(begin(), end()));
205  }
206  static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
207    for (unsigned I = 0, E = AttrList.size(); I != E; ++I)
208      AttrList[I].Profile(ID);
209  }
210};
211
212typedef std::pair<unsigned, AttributeSetNode *> IndexAttrPair;
213
214//===----------------------------------------------------------------------===//
215/// \class
216/// \brief This class represents a set of attributes that apply to the function,
217/// return type, and parameters.
218class AttributeSetImpl final
219    : public FoldingSetNode,
220      private TrailingObjects<AttributeSetImpl, IndexAttrPair> {
221  friend class AttributeSet;
222  friend TrailingObjects;
223
224private:
225  LLVMContext &Context;
226  unsigned NumSlots; ///< Number of entries in this set.
227  /// Bitset with a bit for each available attribute Attribute::AttrKind.
228  uint64_t AvailableFunctionAttrs;
229
230  // Helper fn for TrailingObjects class.
231  size_t numTrailingObjects(OverloadToken<IndexAttrPair>) { return NumSlots; }
232
233  /// \brief Return a pointer to the IndexAttrPair for the specified slot.
234  const IndexAttrPair *getNode(unsigned Slot) const {
235    return getTrailingObjects<IndexAttrPair>() + Slot;
236  }
237
238  // AttributesSet is uniqued, these should not be publicly available.
239  void operator=(const AttributeSetImpl &) = delete;
240  AttributeSetImpl(const AttributeSetImpl &) = delete;
241public:
242  AttributeSetImpl(LLVMContext &C,
243                   ArrayRef<std::pair<unsigned, AttributeSetNode *> > Slots)
244      : Context(C), NumSlots(Slots.size()), AvailableFunctionAttrs(0) {
245    static_assert(Attribute::EndAttrKinds <=
246                      sizeof(AvailableFunctionAttrs) * CHAR_BIT,
247                  "Too many attributes");
248
249#ifndef NDEBUG
250    if (Slots.size() >= 2) {
251      for (const std::pair<unsigned, AttributeSetNode *> *i = Slots.begin() + 1,
252                                                         *e = Slots.end();
253           i != e; ++i) {
254        assert((i-1)->first <= i->first && "Attribute set not ordered!");
255      }
256    }
257#endif
258    // There's memory after the node where we can store the entries in.
259    std::copy(Slots.begin(), Slots.end(), getTrailingObjects<IndexAttrPair>());
260
261    // Initialize AvailableFunctionAttrs summary bitset.
262    if (NumSlots > 0) {
263      static_assert(AttributeSet::FunctionIndex == ~0u,
264                    "FunctionIndex should be biggest possible index");
265      const std::pair<unsigned, AttributeSetNode *> &Last = Slots.back();
266      if (Last.first == AttributeSet::FunctionIndex) {
267        const AttributeSetNode *Node = Last.second;
268        for (Attribute I : *Node) {
269          if (!I.isStringAttribute())
270            AvailableFunctionAttrs |= ((uint64_t)1) << I.getKindAsEnum();
271        }
272      }
273    }
274  }
275
276  void operator delete(void *p) { ::operator delete(p); }
277
278  /// \brief Get the context that created this AttributeSetImpl.
279  LLVMContext &getContext() { return Context; }
280
281  /// \brief Return the number of slots used in this attribute list. This is
282  /// the number of arguments that have an attribute set on them (including the
283  /// function itself).
284  unsigned getNumSlots() const { return NumSlots; }
285
286  /// \brief Get the index of the given "slot" in the AttrNodes list. This index
287  /// is the index of the return, parameter, or function object that the
288  /// attributes are applied to, not the index into the AttrNodes list where the
289  /// attributes reside.
290  unsigned getSlotIndex(unsigned Slot) const {
291    return getNode(Slot)->first;
292  }
293
294  /// \brief Retrieve the attributes for the given "slot" in the AttrNode list.
295  /// \p Slot is an index into the AttrNodes list, not the index of the return /
296  /// parameter/ function which the attributes apply to.
297  AttributeSet getSlotAttributes(unsigned Slot) const {
298    return AttributeSet::get(Context, *getNode(Slot));
299  }
300
301  /// \brief Retrieve the attribute set node for the given "slot" in the
302  /// AttrNode list.
303  AttributeSetNode *getSlotNode(unsigned Slot) const {
304    return getNode(Slot)->second;
305  }
306
307  /// \brief Return true if the AttributeSetNode for the FunctionIndex has an
308  /// enum attribute of the given kind.
309  bool hasFnAttribute(Attribute::AttrKind Kind) const {
310    return AvailableFunctionAttrs & ((uint64_t)1) << Kind;
311  }
312
313  typedef AttributeSetNode::iterator iterator;
314  iterator begin(unsigned Slot) const { return getSlotNode(Slot)->begin(); }
315  iterator end(unsigned Slot) const { return getSlotNode(Slot)->end(); }
316
317  void Profile(FoldingSetNodeID &ID) const {
318    Profile(ID, makeArrayRef(getNode(0), getNumSlots()));
319  }
320  static void Profile(FoldingSetNodeID &ID,
321                      ArrayRef<std::pair<unsigned, AttributeSetNode*> > Nodes) {
322    for (unsigned i = 0, e = Nodes.size(); i != e; ++i) {
323      ID.AddInteger(Nodes[i].first);
324      ID.AddPointer(Nodes[i].second);
325    }
326  }
327
328  // FIXME: This atrocity is temporary.
329  uint64_t Raw(unsigned Index) const;
330
331  void dump() const;
332};
333
334} // end llvm namespace
335
336#endif
337