1 //===-- llvm/Attributes.h - Container for Attributes ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// \brief This file contains the simple types necessary to represent the
12 /// attributes associated with functions and their calls.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_IR_ATTRIBUTES_H
17 #define LLVM_IR_ATTRIBUTES_H
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/Support/PointerLikeTypeTraits.h"
31 class AttributeSetImpl;
32 class AttributeSetNode;
34 template<typename T> struct DenseMapInfo;
38 //===----------------------------------------------------------------------===//
40 /// \brief Functions, function parameters, and return types can have attributes
41 /// to indicate how they should be treated by optimizations and code
42 /// generation. This class represents one of those attributes. It's light-weight
43 /// and should be passed around by-value.
46 /// This enumeration lists the attributes that can be associated with
47 /// parameters, function results, or the function itself.
49 /// Note: The `uwtable' attribute is about the ABI or the user mandating an
50 /// entry in the unwind table. The `nounwind' attribute is about an exception
51 /// passing by the function.
53 /// In a theoretical system that uses tables for profiling and SjLj for
54 /// exceptions, they would be fully independent. In a normal system that uses
55 /// tables for both, the semantics are:
57 /// nil = Needs an entry because an exception might pass by.
58 /// nounwind = No need for an entry
59 /// uwtable = Needs an entry because the ABI says so and because
60 /// an exception might pass by.
61 /// uwtable + nounwind = Needs an entry because the ABI says so.
64 // IR-Level Attributes
65 None, ///< No attributes have been set
66 Alignment, ///< Alignment of parameter (5 bits)
67 ///< stored as log2 of alignment with +1 bias
68 ///< 0 means unaligned (different from align(1))
69 AlwaysInline, ///< inline=always
70 ByVal, ///< Pass structure by value
71 Cold, ///< Marks function as being in a cold path.
72 InlineHint, ///< Source said inlining was desirable
73 InReg, ///< Force argument to be passed in register
74 MinSize, ///< Function must be optimized for size first
75 Naked, ///< Naked function
76 Nest, ///< Nested function static chain
77 NoAlias, ///< Considered to not alias after call
78 NoBuiltin, ///< Callee isn't recognized as a builtin
79 NoCapture, ///< Function creates no aliases of pointer
80 NoDuplicate, ///< Call cannot be duplicated
81 NoImplicitFloat, ///< Disable implicit floating point insts
82 NoInline, ///< inline=never
83 NonLazyBind, ///< Function is called early and/or
84 ///< often, so lazy binding isn't worthwhile
85 NoRedZone, ///< Disable redzone
86 NoReturn, ///< Mark the function as not returning
87 NoUnwind, ///< Function doesn't unwind stack
88 OptimizeForSize, ///< opt_size
89 ReadNone, ///< Function does not access memory
90 ReadOnly, ///< Function only reads from memory
91 Returned, ///< Return value is always equal to this argument
92 ReturnsTwice, ///< Function can return twice
93 SExt, ///< Sign extended before/after call
94 StackAlignment, ///< Alignment of stack for function (3 bits)
95 ///< stored as log2 of alignment with +1 bias 0
96 ///< means unaligned (different from
98 StackProtect, ///< Stack protection.
99 StackProtectReq, ///< Stack protection required.
100 StackProtectStrong, ///< Strong Stack protection.
101 StructRet, ///< Hidden pointer to structure to return
102 SanitizeAddress, ///< AddressSanitizer is on.
103 SanitizeThread, ///< ThreadSanitizer is on.
104 SanitizeMemory, ///< MemorySanitizer is on.
105 UWTable, ///< Function must be in a unwind table
106 ZExt, ///< Zero extended before/after call
108 EndAttrKinds ///< Sentinal value useful for loops
111 AttributeImpl *pImpl;
112 Attribute(AttributeImpl *A) : pImpl(A) {}
114 Attribute() : pImpl(0) {}
116 //===--------------------------------------------------------------------===//
117 // Attribute Construction
118 //===--------------------------------------------------------------------===//
120 /// \brief Return a uniquified Attribute object.
121 static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
122 static Attribute get(LLVMContext &Context, StringRef Kind,
123 StringRef Val = StringRef());
125 /// \brief Return a uniquified Attribute object that has the specific
127 static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
128 static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
130 //===--------------------------------------------------------------------===//
131 // Attribute Accessors
132 //===--------------------------------------------------------------------===//
134 /// \brief Return true if the attribute is an Attribute::AttrKind type.
135 bool isEnumAttribute() const;
137 /// \brief Return true if the attribute is an alignment attribute.
138 bool isAlignAttribute() const;
140 /// \brief Return true if the attribute is a string (target-dependent)
142 bool isStringAttribute() const;
144 /// \brief Return true if the attribute is present.
145 bool hasAttribute(AttrKind Val) const;
147 /// \brief Return true if the target-dependent attribute is present.
148 bool hasAttribute(StringRef Val) const;
150 /// \brief Return the attribute's kind as an enum (Attribute::AttrKind). This
151 /// requires the attribute to be an enum or alignment attribute.
152 Attribute::AttrKind getKindAsEnum() const;
154 /// \brief Return the attribute's value as an integer. This requires that the
155 /// attribute be an alignment attribute.
156 uint64_t getValueAsInt() const;
158 /// \brief Return the attribute's kind as a string. This requires the
159 /// attribute to be a string attribute.
160 StringRef getKindAsString() const;
162 /// \brief Return the attribute's value as a string. This requires the
163 /// attribute to be a string attribute.
164 StringRef getValueAsString() const;
166 /// \brief Returns the alignment field of an attribute as a byte alignment
168 unsigned getAlignment() const;
170 /// \brief Returns the stack alignment field of an attribute as a byte
172 unsigned getStackAlignment() const;
174 /// \brief The Attribute is converted to a string of equivalent mnemonic. This
175 /// is, presumably, for writing out the mnemonics for the assembly writer.
176 std::string getAsString(bool InAttrGrp = false) const;
178 /// \brief Equality and non-equality operators.
179 bool operator==(Attribute A) const { return pImpl == A.pImpl; }
180 bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
182 /// \brief Less-than operator. Useful for sorting the attributes list.
183 bool operator<(Attribute A) const;
185 void Profile(FoldingSetNodeID &ID) const {
186 ID.AddPointer(pImpl);
190 //===----------------------------------------------------------------------===//
192 /// \brief This class holds the attributes for a function, its return value, and
193 /// its parameters. You access the attributes for each of them via an index into
194 /// the AttributeSet object. The function attributes are at index
195 /// `AttributeSet::FunctionIndex', the return value is at index
196 /// `AttributeSet::ReturnIndex', and the attributes for the parameters start at
205 friend class AttrBuilder;
206 friend class AttributeSetImpl;
207 template <typename Ty> friend struct DenseMapInfo;
209 /// \brief The attributes that we are managing. This can be null to represent
210 /// the empty attributes list.
211 AttributeSetImpl *pImpl;
213 /// \brief The attributes for the specified index are returned.
214 AttributeSetNode *getAttributes(unsigned Index) const;
216 /// \brief Create an AttributeSet with the specified parameters in it.
217 static AttributeSet get(LLVMContext &C,
218 ArrayRef<std::pair<unsigned, Attribute> > Attrs);
219 static AttributeSet get(LLVMContext &C,
220 ArrayRef<std::pair<unsigned,
221 AttributeSetNode*> > Attrs);
223 static AttributeSet getImpl(LLVMContext &C,
224 ArrayRef<std::pair<unsigned,
225 AttributeSetNode*> > Attrs);
228 explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
230 AttributeSet() : pImpl(0) {}
232 //===--------------------------------------------------------------------===//
233 // AttributeSet Construction and Mutation
234 //===--------------------------------------------------------------------===//
236 /// \brief Return an AttributeSet with the specified parameters in it.
237 static AttributeSet get(LLVMContext &C, ArrayRef<AttributeSet> Attrs);
238 static AttributeSet get(LLVMContext &C, unsigned Index,
239 ArrayRef<Attribute::AttrKind> Kind);
240 static AttributeSet get(LLVMContext &C, unsigned Index, AttrBuilder &B);
242 /// \brief Add an attribute to the attribute set at the given index. Since
243 /// attribute sets are immutable, this returns a new set.
244 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
245 Attribute::AttrKind Attr) const;
247 /// \brief Add an attribute to the attribute set at the given index. Since
248 /// attribute sets are immutable, this returns a new set.
249 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
250 StringRef Kind) const;
252 /// \brief Add attributes to the attribute set at the given index. Since
253 /// attribute sets are immutable, this returns a new set.
254 AttributeSet addAttributes(LLVMContext &C, unsigned Index,
255 AttributeSet Attrs) const;
257 /// \brief Remove the specified attribute at the specified index from this
258 /// attribute list. Since attribute lists are immutable, this returns the new
260 AttributeSet removeAttribute(LLVMContext &C, unsigned Index,
261 Attribute::AttrKind Attr) const;
263 /// \brief Remove the specified attributes at the specified index from this
264 /// attribute list. Since attribute lists are immutable, this returns the new
266 AttributeSet removeAttributes(LLVMContext &C, unsigned Index,
267 AttributeSet Attrs) const;
269 //===--------------------------------------------------------------------===//
270 // AttributeSet Accessors
271 //===--------------------------------------------------------------------===//
273 /// \brief Retrieve the LLVM context.
274 LLVMContext &getContext() const;
276 /// \brief The attributes for the specified index are returned.
277 AttributeSet getParamAttributes(unsigned Index) const;
279 /// \brief The attributes for the ret value are returned.
280 AttributeSet getRetAttributes() const;
282 /// \brief The function attributes are returned.
283 AttributeSet getFnAttributes() const;
285 /// \brief Return true if the attribute exists at the given index.
286 bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
288 /// \brief Return true if the attribute exists at the given index.
289 bool hasAttribute(unsigned Index, StringRef Kind) const;
291 /// \brief Return true if attribute exists at the given index.
292 bool hasAttributes(unsigned Index) const;
294 /// \brief Return true if the specified attribute is set for at least one
295 /// parameter or for the return value.
296 bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
298 /// \brief Return the attribute object that exists at the given index.
299 Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const;
301 /// \brief Return the attribute object that exists at the given index.
302 Attribute getAttribute(unsigned Index, StringRef Kind) const;
304 /// \brief Return the alignment for the specified function parameter.
305 unsigned getParamAlignment(unsigned Index) const;
307 /// \brief Get the stack alignment.
308 unsigned getStackAlignment(unsigned Index) const;
310 /// \brief Return the attributes at the index as a string.
311 std::string getAsString(unsigned Index, bool InAttrGrp = false) const;
313 typedef ArrayRef<Attribute>::iterator iterator;
315 iterator begin(unsigned Slot) const;
316 iterator end(unsigned Slot) const;
318 /// operator==/!= - Provide equality predicates.
319 bool operator==(const AttributeSet &RHS) const {
320 return pImpl == RHS.pImpl;
322 bool operator!=(const AttributeSet &RHS) const {
323 return pImpl != RHS.pImpl;
326 //===--------------------------------------------------------------------===//
327 // AttributeSet Introspection
328 //===--------------------------------------------------------------------===//
330 // FIXME: Remove this.
331 uint64_t Raw(unsigned Index) const;
333 /// \brief Return a raw pointer that uniquely identifies this attribute list.
334 void *getRawPointer() const {
338 /// \brief Return true if there are no attributes.
339 bool isEmpty() const {
340 return getNumSlots() == 0;
343 /// \brief Return the number of slots used in this attribute list. This is
344 /// the number of arguments that have an attribute set on them (including the
345 /// function itself).
346 unsigned getNumSlots() const;
348 /// \brief Return the index for the given slot.
349 unsigned getSlotIndex(unsigned Slot) const;
351 /// \brief Return the attributes at the given slot.
352 AttributeSet getSlotAttributes(unsigned Slot) const;
357 //===----------------------------------------------------------------------===//
359 /// \brief Provide DenseMapInfo for AttributeSet.
360 template<> struct DenseMapInfo<AttributeSet> {
361 static inline AttributeSet getEmptyKey() {
362 uintptr_t Val = static_cast<uintptr_t>(-1);
363 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
364 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
366 static inline AttributeSet getTombstoneKey() {
367 uintptr_t Val = static_cast<uintptr_t>(-2);
368 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
369 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
371 static unsigned getHashValue(AttributeSet AS) {
372 return (unsigned((uintptr_t)AS.pImpl) >> 4) ^
373 (unsigned((uintptr_t)AS.pImpl) >> 9);
375 static bool isEqual(AttributeSet LHS, AttributeSet RHS) { return LHS == RHS; }
378 //===----------------------------------------------------------------------===//
380 /// \brief This class is used in conjunction with the Attribute::get method to
381 /// create an Attribute object. The object itself is uniquified. The Builder's
382 /// value, however, is not. So this can be used as a quick way to test for
383 /// equality, presence of attributes, etc.
385 std::bitset<Attribute::EndAttrKinds> Attrs;
386 std::map<std::string, std::string> TargetDepAttrs;
388 uint64_t StackAlignment;
390 AttrBuilder() : Attrs(0), Alignment(0), StackAlignment(0) {}
391 explicit AttrBuilder(uint64_t Val)
392 : Attrs(0), Alignment(0), StackAlignment(0) {
395 AttrBuilder(const Attribute &A) : Attrs(0), Alignment(0), StackAlignment(0) {
398 AttrBuilder(AttributeSet AS, unsigned Idx);
399 AttrBuilder(const AttrBuilder &B)
401 TargetDepAttrs(B.TargetDepAttrs.begin(), B.TargetDepAttrs.end()),
402 Alignment(B.Alignment), StackAlignment(B.StackAlignment) {}
406 /// \brief Add an attribute to the builder.
407 AttrBuilder &addAttribute(Attribute::AttrKind Val);
409 /// \brief Add the Attribute object to the builder.
410 AttrBuilder &addAttribute(Attribute A);
412 /// \brief Add the target-dependent attribute to the builder.
413 AttrBuilder &addAttribute(StringRef A, StringRef V = StringRef());
415 /// \brief Remove an attribute from the builder.
416 AttrBuilder &removeAttribute(Attribute::AttrKind Val);
418 /// \brief Remove the attributes from the builder.
419 AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
421 /// \brief Remove the target-dependent attribute to the builder.
422 AttrBuilder &removeAttribute(StringRef A);
424 /// \brief Add the attributes from the builder.
425 AttrBuilder &merge(const AttrBuilder &B);
427 /// \brief Return true if the builder has the specified attribute.
428 bool contains(Attribute::AttrKind A) const {
429 assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
433 /// \brief Return true if the builder has the specified target-dependent
435 bool contains(StringRef A) const;
437 /// \brief Return true if the builder has IR-level attributes.
438 bool hasAttributes() const;
440 /// \brief Return true if the builder has any attribute that's in the
441 /// specified attribute.
442 bool hasAttributes(AttributeSet A, uint64_t Index) const;
444 /// \brief Return true if the builder has an alignment attribute.
445 bool hasAlignmentAttr() const;
447 /// \brief Retrieve the alignment attribute, if it exists.
448 uint64_t getAlignment() const { return Alignment; }
450 /// \brief Retrieve the stack alignment attribute, if it exists.
451 uint64_t getStackAlignment() const { return StackAlignment; }
453 /// \brief This turns an int alignment (which must be a power of 2) into the
454 /// form used internally in Attribute.
455 AttrBuilder &addAlignmentAttr(unsigned Align);
457 /// \brief This turns an int stack alignment (which must be a power of 2) into
458 /// the form used internally in Attribute.
459 AttrBuilder &addStackAlignmentAttr(unsigned Align);
461 /// \brief Return true if the builder contains no target-independent
463 bool empty() const { return Attrs.none(); }
465 // Iterators for target-dependent attributes.
466 typedef std::pair<std::string, std::string> td_type;
467 typedef std::map<std::string, std::string>::iterator td_iterator;
468 typedef std::map<std::string, std::string>::const_iterator td_const_iterator;
470 td_iterator td_begin() { return TargetDepAttrs.begin(); }
471 td_iterator td_end() { return TargetDepAttrs.end(); }
473 td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
474 td_const_iterator td_end() const { return TargetDepAttrs.end(); }
476 bool td_empty() const { return TargetDepAttrs.empty(); }
478 bool operator==(const AttrBuilder &B);
479 bool operator!=(const AttrBuilder &B) {
480 return !(*this == B);
483 // FIXME: Remove this in 4.0.
485 /// \brief Add the raw value to the internal representation.
486 AttrBuilder &addRawValue(uint64_t Val);
489 namespace AttributeFuncs {
491 /// \brief Which attributes cannot be applied to a type.
492 AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
494 } // end AttributeFuncs namespace
496 } // end llvm namespace