xref: /freebsd/contrib/llvm-project/llvm/lib/IR/AttributeImpl.h (revision a8089ea5aee578e08acab2438e82fc9a9ae50ed8) 
1 //===- AttributeImpl.h - Attribute Internals --------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file defines various helper methods and classes used by
11 /// LLVMContextImpl for creating and managing attributes.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_IR_ATTRIBUTEIMPL_H
16 #define LLVM_LIB_IR_ATTRIBUTEIMPL_H
17 
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/ADT/DenseMap.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/ADT/StringRef.h"
22 #include "llvm/IR/Attributes.h"
23 #include "llvm/Support/TrailingObjects.h"
24 #include <cassert>
25 #include <cstddef>
26 #include <cstdint>
27 #include <optional>
28 #include <string>
29 #include <utility>
30 
31 namespace llvm {
32 
33 class LLVMContext;
34 class Type;
35 
36 //===----------------------------------------------------------------------===//
37 /// \class
38 /// This class represents a single, uniqued attribute. That attribute
39 /// could be a single enum, a tuple, or a string.
40 class AttributeImpl : public FoldingSetNode {
41   unsigned char KindID; ///< Holds the AttrEntryKind of the attribute
42 
43 protected:
44   enum AttrEntryKind {
45     EnumAttrEntry,
46     IntAttrEntry,
47     StringAttrEntry,
48     TypeAttrEntry,
49   };
50 
51   AttributeImpl(AttrEntryKind KindID) : KindID(KindID) {}
52 
53 public:
54   // AttributesImpl is uniqued, these should not be available.
55   AttributeImpl(const AttributeImpl &) = delete;
56   AttributeImpl &operator=(const AttributeImpl &) = delete;
57 
58   bool isEnumAttribute() const { return KindID == EnumAttrEntry; }
59   bool isIntAttribute() const { return KindID == IntAttrEntry; }
60   bool isStringAttribute() const { return KindID == StringAttrEntry; }
61   bool isTypeAttribute() const { return KindID == TypeAttrEntry; }
62 
63   bool hasAttribute(Attribute::AttrKind A) const;
64   bool hasAttribute(StringRef Kind) const;
65 
66   Attribute::AttrKind getKindAsEnum() const;
67   uint64_t getValueAsInt() const;
68   bool getValueAsBool() const;
69 
70   StringRef getKindAsString() const;
71   StringRef getValueAsString() const;
72 
73   Type *getValueAsType() const;
74 
75   /// Used when sorting the attributes.
76   bool operator<(const AttributeImpl &AI) const;
77 
78   void Profile(FoldingSetNodeID &ID) const {
79     if (isEnumAttribute())
80       Profile(ID, getKindAsEnum());
81     else if (isIntAttribute())
82       Profile(ID, getKindAsEnum(), getValueAsInt());
83     else if (isStringAttribute())
84       Profile(ID, getKindAsString(), getValueAsString());
85     else
86       Profile(ID, getKindAsEnum(), getValueAsType());
87   }
88 
89   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind) {
90     assert(Attribute::isEnumAttrKind(Kind) && "Expected enum attribute");
91     ID.AddInteger(Kind);
92   }
93 
94   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
95                       uint64_t Val) {
96     assert(Attribute::isIntAttrKind(Kind) && "Expected int attribute");
97     ID.AddInteger(Kind);
98     ID.AddInteger(Val);
99   }
100 
101   static void Profile(FoldingSetNodeID &ID, StringRef Kind, StringRef Values) {
102     ID.AddString(Kind);
103     if (!Values.empty()) ID.AddString(Values);
104   }
105 
106   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
107                       Type *Ty) {
108     ID.AddInteger(Kind);
109     ID.AddPointer(Ty);
110   }
111 };
112 
113 static_assert(std::is_trivially_destructible<AttributeImpl>::value,
114               "AttributeImpl should be trivially destructible");
115 
116 //===----------------------------------------------------------------------===//
117 /// \class
118 /// A set of classes that contain the value of the
119 /// attribute object. There are three main categories: enum attribute entries,
120 /// represented by Attribute::AttrKind; alignment attribute entries; and string
121 /// attribute enties, which are for target-dependent attributes.
122 
123 class EnumAttributeImpl : public AttributeImpl {
124   Attribute::AttrKind Kind;
125 
126 protected:
127   EnumAttributeImpl(AttrEntryKind ID, Attribute::AttrKind Kind)
128       : AttributeImpl(ID), Kind(Kind) {}
129 
130 public:
131   EnumAttributeImpl(Attribute::AttrKind Kind)
132       : AttributeImpl(EnumAttrEntry), Kind(Kind) {
133     assert(Kind != Attribute::AttrKind::None &&
134            "Can't create a None attribute!");
135   }
136 
137   Attribute::AttrKind getEnumKind() const { return Kind; }
138 };
139 
140 class IntAttributeImpl : public EnumAttributeImpl {
141   uint64_t Val;
142 
143 public:
144   IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val)
145       : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
146     assert(Attribute::isIntAttrKind(Kind) &&
147            "Wrong kind for int attribute!");
148   }
149 
150   uint64_t getValue() const { return Val; }
151 };
152 
153 class StringAttributeImpl final
154     : public AttributeImpl,
155       private TrailingObjects<StringAttributeImpl, char> {
156   friend TrailingObjects;
157 
158   unsigned KindSize;
159   unsigned ValSize;
160   size_t numTrailingObjects(OverloadToken<char>) const {
161     return KindSize + 1 + ValSize + 1;
162   }
163 
164 public:
165   StringAttributeImpl(StringRef Kind, StringRef Val = StringRef())
166       : AttributeImpl(StringAttrEntry), KindSize(Kind.size()),
167         ValSize(Val.size()) {
168     char *TrailingString = getTrailingObjects<char>();
169     // Some users rely on zero-termination.
170     llvm::copy(Kind, TrailingString);
171     TrailingString[KindSize] = '\0';
172     llvm::copy(Val, &TrailingString[KindSize + 1]);
173     TrailingString[KindSize + 1 + ValSize] = '\0';
174   }
175 
176   StringRef getStringKind() const {
177     return StringRef(getTrailingObjects<char>(), KindSize);
178   }
179   StringRef getStringValue() const {
180     return StringRef(getTrailingObjects<char>() + KindSize + 1, ValSize);
181   }
182 
183   static size_t totalSizeToAlloc(StringRef Kind, StringRef Val) {
184     return TrailingObjects::totalSizeToAlloc<char>(Kind.size() + 1 +
185                                                    Val.size() + 1);
186   }
187 };
188 
189 class TypeAttributeImpl : public EnumAttributeImpl {
190   Type *Ty;
191 
192 public:
193   TypeAttributeImpl(Attribute::AttrKind Kind, Type *Ty)
194       : EnumAttributeImpl(TypeAttrEntry, Kind), Ty(Ty) {}
195 
196   Type *getTypeValue() const { return Ty; }
197 };
198 
199 class AttributeBitSet {
200   /// Bitset with a bit for each available attribute Attribute::AttrKind.
201   uint8_t AvailableAttrs[12] = {};
202   static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
203                 "Too many attributes");
204 
205 public:
206   bool hasAttribute(Attribute::AttrKind Kind) const {
207     return AvailableAttrs[Kind / 8] & (1 << (Kind % 8));
208   }
209 
210   void addAttribute(Attribute::AttrKind Kind) {
211     AvailableAttrs[Kind / 8] |= 1 << (Kind % 8);
212   }
213 };
214 
215 //===----------------------------------------------------------------------===//
216 /// \class
217 /// This class represents a group of attributes that apply to one
218 /// element: function, return type, or parameter.
219 class AttributeSetNode final
220     : public FoldingSetNode,
221       private TrailingObjects<AttributeSetNode, Attribute> {
222   friend TrailingObjects;
223 
224   unsigned NumAttrs; ///< Number of attributes in this node.
225   AttributeBitSet AvailableAttrs; ///< Available enum attributes.
226 
227   DenseMap<StringRef, Attribute> StringAttrs;
228 
229   AttributeSetNode(ArrayRef<Attribute> Attrs);
230 
231   static AttributeSetNode *getSorted(LLVMContext &C,
232                                      ArrayRef<Attribute> SortedAttrs);
233   std::optional<Attribute> findEnumAttribute(Attribute::AttrKind Kind) const;
234 
235 public:
236   // AttributesSetNode is uniqued, these should not be available.
237   AttributeSetNode(const AttributeSetNode &) = delete;
238   AttributeSetNode &operator=(const AttributeSetNode &) = delete;
239 
240   void operator delete(void *p) { ::operator delete(p); }
241 
242   static AttributeSetNode *get(LLVMContext &C, const AttrBuilder &B);
243 
244   static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
245 
246   /// Return the number of attributes this AttributeList contains.
247   unsigned getNumAttributes() const { return NumAttrs; }
248 
249   bool hasAttribute(Attribute::AttrKind Kind) const {
250     return AvailableAttrs.hasAttribute(Kind);
251   }
252   bool hasAttribute(StringRef Kind) const;
253   bool hasAttributes() const { return NumAttrs != 0; }
254 
255   Attribute getAttribute(Attribute::AttrKind Kind) const;
256   Attribute getAttribute(StringRef Kind) const;
257 
258   MaybeAlign getAlignment() const;
259   MaybeAlign getStackAlignment() const;
260   uint64_t getDereferenceableBytes() const;
261   uint64_t getDereferenceableOrNullBytes() const;
262   std::optional<std::pair<unsigned, std::optional<unsigned>>> getAllocSizeArgs()
263       const;
264   unsigned getVScaleRangeMin() const;
265   std::optional<unsigned> getVScaleRangeMax() const;
266   UWTableKind getUWTableKind() const;
267   AllocFnKind getAllocKind() const;
268   MemoryEffects getMemoryEffects() const;
269   FPClassTest getNoFPClass() const;
270   std::string getAsString(bool InAttrGrp) const;
271   Type *getAttributeType(Attribute::AttrKind Kind) const;
272 
273   using iterator = const Attribute *;
274 
275   iterator begin() const { return getTrailingObjects<Attribute>(); }
276   iterator end() const { return begin() + NumAttrs; }
277 
278   void Profile(FoldingSetNodeID &ID) const {
279     Profile(ID, ArrayRef(begin(), end()));
280   }
281 
282   static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
283     for (const auto &Attr : AttrList)
284       Attr.Profile(ID);
285   }
286 };
287 
288 //===----------------------------------------------------------------------===//
289 /// \class
290 /// This class represents a set of attributes that apply to the function,
291 /// return type, and parameters.
292 class AttributeListImpl final
293     : public FoldingSetNode,
294       private TrailingObjects<AttributeListImpl, AttributeSet> {
295   friend class AttributeList;
296   friend TrailingObjects;
297 
298 private:
299   unsigned NumAttrSets; ///< Number of entries in this set.
300   /// Available enum function attributes.
301   AttributeBitSet AvailableFunctionAttrs;
302   /// Union of enum attributes available at any index.
303   AttributeBitSet AvailableSomewhereAttrs;
304 
305   // Helper fn for TrailingObjects class.
306   size_t numTrailingObjects(OverloadToken<AttributeSet>) { return NumAttrSets; }
307 
308 public:
309   AttributeListImpl(ArrayRef<AttributeSet> Sets);
310 
311   // AttributesSetImpt is uniqued, these should not be available.
312   AttributeListImpl(const AttributeListImpl &) = delete;
313   AttributeListImpl &operator=(const AttributeListImpl &) = delete;
314 
315   /// Return true if the AttributeSet or the FunctionIndex has an
316   /// enum attribute of the given kind.
317   bool hasFnAttribute(Attribute::AttrKind Kind) const {
318     return AvailableFunctionAttrs.hasAttribute(Kind);
319   }
320 
321   /// Return true if the specified attribute is set for at least one
322   /// parameter or for the return value. If Index is not nullptr, the index
323   /// of a parameter with the specified attribute is provided.
324   bool hasAttrSomewhere(Attribute::AttrKind Kind,
325                         unsigned *Index = nullptr) const;
326 
327   using iterator = const AttributeSet *;
328 
329   iterator begin() const { return getTrailingObjects<AttributeSet>(); }
330   iterator end() const { return begin() + NumAttrSets; }
331 
332   void Profile(FoldingSetNodeID &ID) const;
333   static void Profile(FoldingSetNodeID &ID, ArrayRef<AttributeSet> Nodes);
334 
335   void dump() const;
336 };
337 
338 static_assert(std::is_trivially_destructible<AttributeListImpl>::value,
339               "AttributeListImpl should be trivially destructible");
340 
341 } // end namespace llvm
342 
343 #endif // LLVM_LIB_IR_ATTRIBUTEIMPL_H
344