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 Builtin, ///< Callee is recognized as a builtin, despite
71 ///< nobuiltin attribute on its declaration.
72 ByVal, ///< Pass structure by value
73 Cold, ///< Marks function as being in a cold path.
74 InlineHint, ///< Source said inlining was desirable
75 InReg, ///< Force argument to be passed in register
76 MinSize, ///< Function must be optimized for size first
77 Naked, ///< Naked function
78 Nest, ///< Nested function static chain
79 NoAlias, ///< Considered to not alias after call
80 NoBuiltin, ///< Callee isn't recognized as a builtin
81 NoCapture, ///< Function creates no aliases of pointer
82 NoDuplicate, ///< Call cannot be duplicated
83 NoImplicitFloat, ///< Disable implicit floating point insts
84 NoInline, ///< inline=never
85 NonLazyBind, ///< Function is called early and/or
86 ///< often, so lazy binding isn't worthwhile
87 NoRedZone, ///< Disable redzone
88 NoReturn, ///< Mark the function as not returning
89 NoUnwind, ///< Function doesn't unwind stack
90 OptimizeForSize, ///< opt_size
91 OptimizeNone, ///< Function must not be optimized.
92 ReadNone, ///< Function does not access memory
93 ReadOnly, ///< Function only reads from memory
94 Returned, ///< Return value is always equal to this argument
95 ReturnsTwice, ///< Function can return twice
96 SExt, ///< Sign extended before/after call
97 StackAlignment, ///< Alignment of stack for function (3 bits)
98 ///< stored as log2 of alignment with +1 bias 0
99 ///< means unaligned (different from
101 StackProtect, ///< Stack protection.
102 StackProtectReq, ///< Stack protection required.
103 StackProtectStrong, ///< Strong Stack protection.
104 StructRet, ///< Hidden pointer to structure to return
105 SanitizeAddress, ///< AddressSanitizer is on.
106 SanitizeThread, ///< ThreadSanitizer is on.
107 SanitizeMemory, ///< MemorySanitizer is on.
108 UWTable, ///< Function must be in a unwind table
109 ZExt, ///< Zero extended before/after call
111 EndAttrKinds ///< Sentinal value useful for loops
114 AttributeImpl *pImpl;
115 Attribute(AttributeImpl *A) : pImpl(A) {}
117 Attribute() : pImpl(0) {}
119 //===--------------------------------------------------------------------===//
120 // Attribute Construction
121 //===--------------------------------------------------------------------===//
123 /// \brief Return a uniquified Attribute object.
124 static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
125 static Attribute get(LLVMContext &Context, StringRef Kind,
126 StringRef Val = StringRef());
128 /// \brief Return a uniquified Attribute object that has the specific
130 static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
131 static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
133 //===--------------------------------------------------------------------===//
134 // Attribute Accessors
135 //===--------------------------------------------------------------------===//
137 /// \brief Return true if the attribute is an Attribute::AttrKind type.
138 bool isEnumAttribute() const;
140 /// \brief Return true if the attribute is an alignment attribute.
141 bool isAlignAttribute() const;
143 /// \brief Return true if the attribute is a string (target-dependent)
145 bool isStringAttribute() const;
147 /// \brief Return true if the attribute is present.
148 bool hasAttribute(AttrKind Val) const;
150 /// \brief Return true if the target-dependent attribute is present.
151 bool hasAttribute(StringRef Val) const;
153 /// \brief Return the attribute's kind as an enum (Attribute::AttrKind). This
154 /// requires the attribute to be an enum or alignment attribute.
155 Attribute::AttrKind getKindAsEnum() const;
157 /// \brief Return the attribute's value as an integer. This requires that the
158 /// attribute be an alignment attribute.
159 uint64_t getValueAsInt() const;
161 /// \brief Return the attribute's kind as a string. This requires the
162 /// attribute to be a string attribute.
163 StringRef getKindAsString() const;
165 /// \brief Return the attribute's value as a string. This requires the
166 /// attribute to be a string attribute.
167 StringRef getValueAsString() const;
169 /// \brief Returns the alignment field of an attribute as a byte alignment
171 unsigned getAlignment() const;
173 /// \brief Returns the stack alignment field of an attribute as a byte
175 unsigned getStackAlignment() const;
177 /// \brief The Attribute is converted to a string of equivalent mnemonic. This
178 /// is, presumably, for writing out the mnemonics for the assembly writer.
179 std::string getAsString(bool InAttrGrp = false) const;
181 /// \brief Equality and non-equality operators.
182 bool operator==(Attribute A) const { return pImpl == A.pImpl; }
183 bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
185 /// \brief Less-than operator. Useful for sorting the attributes list.
186 bool operator<(Attribute A) const;
188 void Profile(FoldingSetNodeID &ID) const {
189 ID.AddPointer(pImpl);
193 //===----------------------------------------------------------------------===//
195 /// \brief This class holds the attributes for a function, its return value, and
196 /// its parameters. You access the attributes for each of them via an index into
197 /// the AttributeSet object. The function attributes are at index
198 /// `AttributeSet::FunctionIndex', the return value is at index
199 /// `AttributeSet::ReturnIndex', and the attributes for the parameters start at
208 friend class AttrBuilder;
209 friend class AttributeSetImpl;
210 template <typename Ty> friend struct DenseMapInfo;
212 /// \brief The attributes that we are managing. This can be null to represent
213 /// the empty attributes list.
214 AttributeSetImpl *pImpl;
216 /// \brief The attributes for the specified index are returned.
217 AttributeSetNode *getAttributes(unsigned Index) const;
219 /// \brief Create an AttributeSet with the specified parameters in it.
220 static AttributeSet get(LLVMContext &C,
221 ArrayRef<std::pair<unsigned, Attribute> > Attrs);
222 static AttributeSet get(LLVMContext &C,
223 ArrayRef<std::pair<unsigned,
224 AttributeSetNode*> > Attrs);
226 static AttributeSet getImpl(LLVMContext &C,
227 ArrayRef<std::pair<unsigned,
228 AttributeSetNode*> > Attrs);
231 explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
233 AttributeSet() : pImpl(0) {}
235 //===--------------------------------------------------------------------===//
236 // AttributeSet Construction and Mutation
237 //===--------------------------------------------------------------------===//
239 /// \brief Return an AttributeSet with the specified parameters in it.
240 static AttributeSet get(LLVMContext &C, ArrayRef<AttributeSet> Attrs);
241 static AttributeSet get(LLVMContext &C, unsigned Index,
242 ArrayRef<Attribute::AttrKind> Kind);
243 static AttributeSet get(LLVMContext &C, unsigned Index, AttrBuilder &B);
245 /// \brief Add an attribute to the attribute set at the given index. Since
246 /// attribute sets are immutable, this returns a new set.
247 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
248 Attribute::AttrKind Attr) const;
250 /// \brief Add an attribute to the attribute set at the given index. Since
251 /// attribute sets are immutable, this returns a new set.
252 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
253 StringRef Kind) const;
254 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
255 StringRef Kind, StringRef Value) const;
257 /// \brief Add attributes to the attribute set at the given index. Since
258 /// attribute sets are immutable, this returns a new set.
259 AttributeSet addAttributes(LLVMContext &C, unsigned Index,
260 AttributeSet Attrs) const;
262 /// \brief Remove the specified attribute at the specified index from this
263 /// attribute list. Since attribute lists are immutable, this returns the new
265 AttributeSet removeAttribute(LLVMContext &C, unsigned Index,
266 Attribute::AttrKind Attr) const;
268 /// \brief Remove the specified attributes at the specified index from this
269 /// attribute list. Since attribute lists are immutable, this returns the new
271 AttributeSet removeAttributes(LLVMContext &C, unsigned Index,
272 AttributeSet Attrs) const;
274 //===--------------------------------------------------------------------===//
275 // AttributeSet Accessors
276 //===--------------------------------------------------------------------===//
278 /// \brief Retrieve the LLVM context.
279 LLVMContext &getContext() const;
281 /// \brief The attributes for the specified index are returned.
282 AttributeSet getParamAttributes(unsigned Index) const;
284 /// \brief The attributes for the ret value are returned.
285 AttributeSet getRetAttributes() const;
287 /// \brief The function attributes are returned.
288 AttributeSet getFnAttributes() const;
290 /// \brief Return true if the attribute exists at the given index.
291 bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
293 /// \brief Return true if the attribute exists at the given index.
294 bool hasAttribute(unsigned Index, StringRef Kind) const;
296 /// \brief Return true if attribute exists at the given index.
297 bool hasAttributes(unsigned Index) const;
299 /// \brief Return true if the specified attribute is set for at least one
300 /// parameter or for the return value.
301 bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
303 /// \brief Return the attribute object that exists at the given index.
304 Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const;
306 /// \brief Return the attribute object that exists at the given index.
307 Attribute getAttribute(unsigned Index, StringRef Kind) const;
309 /// \brief Return the alignment for the specified function parameter.
310 unsigned getParamAlignment(unsigned Index) const;
312 /// \brief Get the stack alignment.
313 unsigned getStackAlignment(unsigned Index) const;
315 /// \brief Return the attributes at the index as a string.
316 std::string getAsString(unsigned Index, bool InAttrGrp = false) const;
318 typedef ArrayRef<Attribute>::iterator iterator;
320 iterator begin(unsigned Slot) const;
321 iterator end(unsigned Slot) const;
323 /// operator==/!= - Provide equality predicates.
324 bool operator==(const AttributeSet &RHS) const {
325 return pImpl == RHS.pImpl;
327 bool operator!=(const AttributeSet &RHS) const {
328 return pImpl != RHS.pImpl;
331 //===--------------------------------------------------------------------===//
332 // AttributeSet Introspection
333 //===--------------------------------------------------------------------===//
335 // FIXME: Remove this.
336 uint64_t Raw(unsigned Index) const;
338 /// \brief Return a raw pointer that uniquely identifies this attribute list.
339 void *getRawPointer() const {
343 /// \brief Return true if there are no attributes.
344 bool isEmpty() const {
345 return getNumSlots() == 0;
348 /// \brief Return the number of slots used in this attribute list. This is
349 /// the number of arguments that have an attribute set on them (including the
350 /// function itself).
351 unsigned getNumSlots() const;
353 /// \brief Return the index for the given slot.
354 unsigned getSlotIndex(unsigned Slot) const;
356 /// \brief Return the attributes at the given slot.
357 AttributeSet getSlotAttributes(unsigned Slot) const;
362 //===----------------------------------------------------------------------===//
364 /// \brief Provide DenseMapInfo for AttributeSet.
365 template<> struct DenseMapInfo<AttributeSet> {
366 static inline AttributeSet getEmptyKey() {
367 uintptr_t Val = static_cast<uintptr_t>(-1);
368 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
369 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
371 static inline AttributeSet getTombstoneKey() {
372 uintptr_t Val = static_cast<uintptr_t>(-2);
373 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
374 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
376 static unsigned getHashValue(AttributeSet AS) {
377 return (unsigned((uintptr_t)AS.pImpl) >> 4) ^
378 (unsigned((uintptr_t)AS.pImpl) >> 9);
380 static bool isEqual(AttributeSet LHS, AttributeSet RHS) { return LHS == RHS; }
383 //===----------------------------------------------------------------------===//
385 /// \brief This class is used in conjunction with the Attribute::get method to
386 /// create an Attribute object. The object itself is uniquified. The Builder's
387 /// value, however, is not. So this can be used as a quick way to test for
388 /// equality, presence of attributes, etc.
390 std::bitset<Attribute::EndAttrKinds> Attrs;
391 std::map<std::string, std::string> TargetDepAttrs;
393 uint64_t StackAlignment;
395 AttrBuilder() : Attrs(0), Alignment(0), StackAlignment(0) {}
396 explicit AttrBuilder(uint64_t Val)
397 : Attrs(0), Alignment(0), StackAlignment(0) {
400 AttrBuilder(const Attribute &A) : Attrs(0), Alignment(0), StackAlignment(0) {
403 AttrBuilder(AttributeSet AS, unsigned Idx);
404 AttrBuilder(const AttrBuilder &B)
406 TargetDepAttrs(B.TargetDepAttrs.begin(), B.TargetDepAttrs.end()),
407 Alignment(B.Alignment), StackAlignment(B.StackAlignment) {}
411 /// \brief Add an attribute to the builder.
412 AttrBuilder &addAttribute(Attribute::AttrKind Val);
414 /// \brief Add the Attribute object to the builder.
415 AttrBuilder &addAttribute(Attribute A);
417 /// \brief Add the target-dependent attribute to the builder.
418 AttrBuilder &addAttribute(StringRef A, StringRef V = StringRef());
420 /// \brief Remove an attribute from the builder.
421 AttrBuilder &removeAttribute(Attribute::AttrKind Val);
423 /// \brief Remove the attributes from the builder.
424 AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
426 /// \brief Remove the target-dependent attribute to the builder.
427 AttrBuilder &removeAttribute(StringRef A);
429 /// \brief Add the attributes from the builder.
430 AttrBuilder &merge(const AttrBuilder &B);
432 /// \brief Return true if the builder has the specified attribute.
433 bool contains(Attribute::AttrKind A) const {
434 assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
438 /// \brief Return true if the builder has the specified target-dependent
440 bool contains(StringRef A) const;
442 /// \brief Return true if the builder has IR-level attributes.
443 bool hasAttributes() const;
445 /// \brief Return true if the builder has any attribute that's in the
446 /// specified attribute.
447 bool hasAttributes(AttributeSet A, uint64_t Index) const;
449 /// \brief Return true if the builder has an alignment attribute.
450 bool hasAlignmentAttr() const;
452 /// \brief Retrieve the alignment attribute, if it exists.
453 uint64_t getAlignment() const { return Alignment; }
455 /// \brief Retrieve the stack alignment attribute, if it exists.
456 uint64_t getStackAlignment() const { return StackAlignment; }
458 /// \brief This turns an int alignment (which must be a power of 2) into the
459 /// form used internally in Attribute.
460 AttrBuilder &addAlignmentAttr(unsigned Align);
462 /// \brief This turns an int stack alignment (which must be a power of 2) into
463 /// the form used internally in Attribute.
464 AttrBuilder &addStackAlignmentAttr(unsigned Align);
466 /// \brief Return true if the builder contains no target-independent
468 bool empty() const { return Attrs.none(); }
470 // Iterators for target-dependent attributes.
471 typedef std::pair<std::string, std::string> td_type;
472 typedef std::map<std::string, std::string>::iterator td_iterator;
473 typedef std::map<std::string, std::string>::const_iterator td_const_iterator;
475 td_iterator td_begin() { return TargetDepAttrs.begin(); }
476 td_iterator td_end() { return TargetDepAttrs.end(); }
478 td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
479 td_const_iterator td_end() const { return TargetDepAttrs.end(); }
481 bool td_empty() const { return TargetDepAttrs.empty(); }
483 bool operator==(const AttrBuilder &B);
484 bool operator!=(const AttrBuilder &B) {
485 return !(*this == B);
488 // FIXME: Remove this in 4.0.
490 /// \brief Add the raw value to the internal representation.
491 AttrBuilder &addRawValue(uint64_t Val);
494 namespace AttributeFuncs {
496 /// \brief Which attributes cannot be applied to a type.
497 AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
499 } // end AttributeFuncs namespace
501 } // end llvm namespace