xref: /llvm-project/llvm/lib/IR/AttributeImpl.h (revision 22e9024c9f374c0c740647829050c289673dbb11) 
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/IR/ConstantRange.h"
24 #include "llvm/IR/ConstantRangeList.h"
25 #include "llvm/Support/TrailingObjects.h"
26 #include <cassert>
27 #include <cstddef>
28 #include <cstdint>
29 #include <optional>
30 #include <string>
31 #include <utility>
32 
33 namespace llvm {
34 
35 class LLVMContext;
36 class Type;
37 
38 //===----------------------------------------------------------------------===//
39 /// \class
40 /// This class represents a single, uniqued attribute. That attribute
41 /// could be a single enum, a tuple, or a string.
42 class AttributeImpl : public FoldingSetNode {
43   unsigned char KindID; ///< Holds the AttrEntryKind of the attribute
44 
45 protected:
46   enum AttrEntryKind {
47     EnumAttrEntry,
48     IntAttrEntry,
49     StringAttrEntry,
50     TypeAttrEntry,
51     ConstantRangeAttrEntry,
52     ConstantRangeListAttrEntry,
53   };
54 
55   AttributeImpl(AttrEntryKind KindID) : KindID(KindID) {}
56 
57 public:
58   // AttributesImpl is uniqued, these should not be available.
59   AttributeImpl(const AttributeImpl &) = delete;
60   AttributeImpl &operator=(const AttributeImpl &) = delete;
61 
62   bool isEnumAttribute() const { return KindID == EnumAttrEntry; }
63   bool isIntAttribute() const { return KindID == IntAttrEntry; }
64   bool isStringAttribute() const { return KindID == StringAttrEntry; }
65   bool isTypeAttribute() const { return KindID == TypeAttrEntry; }
66   bool isConstantRangeAttribute() const {
67     return KindID == ConstantRangeAttrEntry;
68   }
69   bool isConstantRangeListAttribute() const {
70     return KindID == ConstantRangeListAttrEntry;
71   }
72 
73   bool hasAttribute(Attribute::AttrKind A) const;
74   bool hasAttribute(StringRef Kind) const;
75 
76   Attribute::AttrKind getKindAsEnum() const;
77   uint64_t getValueAsInt() const;
78   bool getValueAsBool() const;
79 
80   StringRef getKindAsString() const;
81   StringRef getValueAsString() const;
82 
83   Type *getValueAsType() const;
84 
85   const ConstantRange &getValueAsConstantRange() const;
86 
87   ArrayRef<ConstantRange> getValueAsConstantRangeList() const;
88 
89   /// Used to sort attributes. KindOnly controls if the sort includes the
90   /// attributes' values or just the kind.
91   int cmp(const AttributeImpl &AI, bool KindOnly) const;
92   /// Used when sorting the attributes.
93   bool operator<(const AttributeImpl &AI) const;
94 
95   void Profile(FoldingSetNodeID &ID) const {
96     if (isEnumAttribute())
97       Profile(ID, getKindAsEnum());
98     else if (isIntAttribute())
99       Profile(ID, getKindAsEnum(), getValueAsInt());
100     else if (isStringAttribute())
101       Profile(ID, getKindAsString(), getValueAsString());
102     else if (isTypeAttribute())
103       Profile(ID, getKindAsEnum(), getValueAsType());
104     else if (isConstantRangeAttribute())
105       Profile(ID, getKindAsEnum(), getValueAsConstantRange());
106     else
107       Profile(ID, getKindAsEnum(), getValueAsConstantRangeList());
108   }
109 
110   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind) {
111     assert(Attribute::isEnumAttrKind(Kind) && "Expected enum attribute");
112     ID.AddInteger(Kind);
113   }
114 
115   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
116                       uint64_t Val) {
117     assert(Attribute::isIntAttrKind(Kind) && "Expected int attribute");
118     ID.AddInteger(Kind);
119     ID.AddInteger(Val);
120   }
121 
122   static void Profile(FoldingSetNodeID &ID, StringRef Kind, StringRef Values) {
123     ID.AddString(Kind);
124     if (!Values.empty()) ID.AddString(Values);
125   }
126 
127   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
128                       Type *Ty) {
129     ID.AddInteger(Kind);
130     ID.AddPointer(Ty);
131   }
132 
133   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
134                       const ConstantRange &CR) {
135     ID.AddInteger(Kind);
136     CR.getLower().Profile(ID);
137     CR.getUpper().Profile(ID);
138   }
139 
140   static void Profile(FoldingSetNodeID &ID, Attribute::AttrKind Kind,
141                       ArrayRef<ConstantRange> Val) {
142     ID.AddInteger(Kind);
143     ID.AddInteger(Val.size());
144     for (auto &CR : Val) {
145       CR.getLower().Profile(ID);
146       CR.getUpper().Profile(ID);
147     }
148   }
149 };
150 
151 static_assert(std::is_trivially_destructible<AttributeImpl>::value,
152               "AttributeImpl should be trivially destructible");
153 
154 //===----------------------------------------------------------------------===//
155 /// \class
156 /// A set of classes that contain the value of the
157 /// attribute object. There are three main categories: enum attribute entries,
158 /// represented by Attribute::AttrKind; alignment attribute entries; and string
159 /// attribute enties, which are for target-dependent attributes.
160 
161 class EnumAttributeImpl : public AttributeImpl {
162   Attribute::AttrKind Kind;
163 
164 protected:
165   EnumAttributeImpl(AttrEntryKind ID, Attribute::AttrKind Kind)
166       : AttributeImpl(ID), Kind(Kind) {}
167 
168 public:
169   EnumAttributeImpl(Attribute::AttrKind Kind)
170       : AttributeImpl(EnumAttrEntry), Kind(Kind) {
171     assert(Kind != Attribute::AttrKind::None &&
172            "Can't create a None attribute!");
173   }
174 
175   Attribute::AttrKind getEnumKind() const { return Kind; }
176 };
177 
178 class IntAttributeImpl : public EnumAttributeImpl {
179   uint64_t Val;
180 
181 public:
182   IntAttributeImpl(Attribute::AttrKind Kind, uint64_t Val)
183       : EnumAttributeImpl(IntAttrEntry, Kind), Val(Val) {
184     assert(Attribute::isIntAttrKind(Kind) &&
185            "Wrong kind for int attribute!");
186   }
187 
188   uint64_t getValue() const { return Val; }
189 };
190 
191 class StringAttributeImpl final
192     : public AttributeImpl,
193       private TrailingObjects<StringAttributeImpl, char> {
194   friend TrailingObjects;
195 
196   unsigned KindSize;
197   unsigned ValSize;
198   size_t numTrailingObjects(OverloadToken<char>) const {
199     return KindSize + 1 + ValSize + 1;
200   }
201 
202 public:
203   StringAttributeImpl(StringRef Kind, StringRef Val = StringRef())
204       : AttributeImpl(StringAttrEntry), KindSize(Kind.size()),
205         ValSize(Val.size()) {
206     char *TrailingString = getTrailingObjects<char>();
207     // Some users rely on zero-termination.
208     llvm::copy(Kind, TrailingString);
209     TrailingString[KindSize] = '\0';
210     llvm::copy(Val, &TrailingString[KindSize + 1]);
211     TrailingString[KindSize + 1 + ValSize] = '\0';
212   }
213 
214   StringRef getStringKind() const {
215     return StringRef(getTrailingObjects<char>(), KindSize);
216   }
217   StringRef getStringValue() const {
218     return StringRef(getTrailingObjects<char>() + KindSize + 1, ValSize);
219   }
220 
221   static size_t totalSizeToAlloc(StringRef Kind, StringRef Val) {
222     return TrailingObjects::totalSizeToAlloc<char>(Kind.size() + 1 +
223                                                    Val.size() + 1);
224   }
225 };
226 
227 class TypeAttributeImpl : public EnumAttributeImpl {
228   Type *Ty;
229 
230 public:
231   TypeAttributeImpl(Attribute::AttrKind Kind, Type *Ty)
232       : EnumAttributeImpl(TypeAttrEntry, Kind), Ty(Ty) {}
233 
234   Type *getTypeValue() const { return Ty; }
235 };
236 
237 class ConstantRangeAttributeImpl : public EnumAttributeImpl {
238   ConstantRange CR;
239 
240 public:
241   ConstantRangeAttributeImpl(Attribute::AttrKind Kind, const ConstantRange &CR)
242       : EnumAttributeImpl(ConstantRangeAttrEntry, Kind), CR(CR) {}
243 
244   const ConstantRange &getConstantRangeValue() const { return CR; }
245 };
246 
247 class ConstantRangeListAttributeImpl final
248     : public EnumAttributeImpl,
249       private TrailingObjects<ConstantRangeListAttributeImpl, ConstantRange> {
250   friend TrailingObjects;
251 
252   unsigned Size;
253   size_t numTrailingObjects(OverloadToken<ConstantRange>) const { return Size; }
254 
255 public:
256   ConstantRangeListAttributeImpl(Attribute::AttrKind Kind,
257                                  ArrayRef<ConstantRange> Val)
258       : EnumAttributeImpl(ConstantRangeListAttrEntry, Kind), Size(Val.size()) {
259     assert(Size > 0);
260     ConstantRange *TrailingCR = getTrailingObjects<ConstantRange>();
261     std::uninitialized_copy(Val.begin(), Val.end(), TrailingCR);
262   }
263 
264   ~ConstantRangeListAttributeImpl() {
265     ConstantRange *TrailingCR = getTrailingObjects<ConstantRange>();
266     for (unsigned I = 0; I != Size; ++I)
267       TrailingCR[I].~ConstantRange();
268   }
269 
270   ArrayRef<ConstantRange> getConstantRangeListValue() const {
271     return ArrayRef(getTrailingObjects<ConstantRange>(), Size);
272   }
273 
274   static size_t totalSizeToAlloc(ArrayRef<ConstantRange> Val) {
275     return TrailingObjects::totalSizeToAlloc<ConstantRange>(Val.size());
276   }
277 };
278 
279 class AttributeBitSet {
280   /// Bitset with a bit for each available attribute Attribute::AttrKind.
281   uint8_t AvailableAttrs[16] = {};
282   static_assert(Attribute::EndAttrKinds <= sizeof(AvailableAttrs) * CHAR_BIT,
283                 "Too many attributes");
284 
285 public:
286   bool hasAttribute(Attribute::AttrKind Kind) const {
287     return AvailableAttrs[Kind / 8] & (1 << (Kind % 8));
288   }
289 
290   void addAttribute(Attribute::AttrKind Kind) {
291     AvailableAttrs[Kind / 8] |= 1 << (Kind % 8);
292   }
293 };
294 
295 //===----------------------------------------------------------------------===//
296 /// \class
297 /// This class represents a group of attributes that apply to one
298 /// element: function, return type, or parameter.
299 class AttributeSetNode final
300     : public FoldingSetNode,
301       private TrailingObjects<AttributeSetNode, Attribute> {
302   friend TrailingObjects;
303 
304   unsigned NumAttrs; ///< Number of attributes in this node.
305   AttributeBitSet AvailableAttrs; ///< Available enum attributes.
306 
307   DenseMap<StringRef, Attribute> StringAttrs;
308 
309   AttributeSetNode(ArrayRef<Attribute> Attrs);
310 
311   static AttributeSetNode *getSorted(LLVMContext &C,
312                                      ArrayRef<Attribute> SortedAttrs);
313   std::optional<Attribute> findEnumAttribute(Attribute::AttrKind Kind) const;
314 
315 public:
316   // AttributesSetNode is uniqued, these should not be available.
317   AttributeSetNode(const AttributeSetNode &) = delete;
318   AttributeSetNode &operator=(const AttributeSetNode &) = delete;
319 
320   void operator delete(void *p) { ::operator delete(p); }
321 
322   static AttributeSetNode *get(LLVMContext &C, const AttrBuilder &B);
323 
324   static AttributeSetNode *get(LLVMContext &C, ArrayRef<Attribute> Attrs);
325 
326   /// Return the number of attributes this AttributeList contains.
327   unsigned getNumAttributes() const { return NumAttrs; }
328 
329   bool hasAttribute(Attribute::AttrKind Kind) const {
330     return AvailableAttrs.hasAttribute(Kind);
331   }
332   bool hasAttribute(StringRef Kind) const;
333   bool hasAttributes() const { return NumAttrs != 0; }
334 
335   Attribute getAttribute(Attribute::AttrKind Kind) const;
336   Attribute getAttribute(StringRef Kind) const;
337 
338   MaybeAlign getAlignment() const;
339   MaybeAlign getStackAlignment() const;
340   uint64_t getDereferenceableBytes() const;
341   uint64_t getDereferenceableOrNullBytes() const;
342   std::optional<std::pair<unsigned, std::optional<unsigned>>> getAllocSizeArgs()
343       const;
344   unsigned getVScaleRangeMin() const;
345   std::optional<unsigned> getVScaleRangeMax() const;
346   UWTableKind getUWTableKind() const;
347   AllocFnKind getAllocKind() const;
348   MemoryEffects getMemoryEffects() const;
349   CaptureInfo getCaptureInfo() const;
350   FPClassTest getNoFPClass() const;
351   std::string getAsString(bool InAttrGrp) const;
352   Type *getAttributeType(Attribute::AttrKind Kind) const;
353 
354   using iterator = const Attribute *;
355 
356   iterator begin() const { return getTrailingObjects<Attribute>(); }
357   iterator end() const { return begin() + NumAttrs; }
358 
359   void Profile(FoldingSetNodeID &ID) const {
360     Profile(ID, ArrayRef(begin(), end()));
361   }
362 
363   static void Profile(FoldingSetNodeID &ID, ArrayRef<Attribute> AttrList) {
364     for (const auto &Attr : AttrList)
365       Attr.Profile(ID);
366   }
367 };
368 
369 //===----------------------------------------------------------------------===//
370 /// \class
371 /// This class represents a set of attributes that apply to the function,
372 /// return type, and parameters.
373 class AttributeListImpl final
374     : public FoldingSetNode,
375       private TrailingObjects<AttributeListImpl, AttributeSet> {
376   friend class AttributeList;
377   friend TrailingObjects;
378 
379 private:
380   unsigned NumAttrSets; ///< Number of entries in this set.
381   /// Available enum function attributes.
382   AttributeBitSet AvailableFunctionAttrs;
383   /// Union of enum attributes available at any index.
384   AttributeBitSet AvailableSomewhereAttrs;
385 
386   // Helper fn for TrailingObjects class.
387   size_t numTrailingObjects(OverloadToken<AttributeSet>) { return NumAttrSets; }
388 
389 public:
390   AttributeListImpl(ArrayRef<AttributeSet> Sets);
391 
392   // AttributesSetImpt is uniqued, these should not be available.
393   AttributeListImpl(const AttributeListImpl &) = delete;
394   AttributeListImpl &operator=(const AttributeListImpl &) = delete;
395 
396   /// Return true if the AttributeSet or the FunctionIndex has an
397   /// enum attribute of the given kind.
398   bool hasFnAttribute(Attribute::AttrKind Kind) const {
399     return AvailableFunctionAttrs.hasAttribute(Kind);
400   }
401 
402   /// Return true if the specified attribute is set for at least one
403   /// parameter or for the return value. If Index is not nullptr, the index
404   /// of a parameter with the specified attribute is provided.
405   bool hasAttrSomewhere(Attribute::AttrKind Kind,
406                         unsigned *Index = nullptr) const;
407 
408   using iterator = const AttributeSet *;
409 
410   iterator begin() const { return getTrailingObjects<AttributeSet>(); }
411   iterator end() const { return begin() + NumAttrSets; }
412 
413   void Profile(FoldingSetNodeID &ID) const;
414   static void Profile(FoldingSetNodeID &ID, ArrayRef<AttributeSet> Nodes);
415 
416   void dump() const;
417 };
418 
419 static_assert(std::is_trivially_destructible<AttributeListImpl>::value,
420               "AttributeListImpl should be trivially destructible");
421 
422 } // end namespace llvm
423 
424 #endif // LLVM_LIB_IR_ATTRIBUTEIMPL_H
425