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 ReadNone, ///< Function does not access memory
92 ReadOnly, ///< Function only reads from memory
93 Returned, ///< Return value is always equal to this argument
94 ReturnsTwice, ///< Function can return twice
95 SExt, ///< Sign extended before/after call
96 StackAlignment, ///< Alignment of stack for function (3 bits)
97 ///< stored as log2 of alignment with +1 bias 0
98 ///< means unaligned (different from
100 StackProtect, ///< Stack protection.
101 StackProtectReq, ///< Stack protection required.
102 StackProtectStrong, ///< Strong Stack protection.
103 StructRet, ///< Hidden pointer to structure to return
104 SanitizeAddress, ///< AddressSanitizer is on.
105 SanitizeThread, ///< ThreadSanitizer is on.
106 SanitizeMemory, ///< MemorySanitizer is on.
107 UWTable, ///< Function must be in a unwind table
108 ZExt, ///< Zero extended before/after call
110 EndAttrKinds ///< Sentinal value useful for loops
113 AttributeImpl *pImpl;
114 Attribute(AttributeImpl *A) : pImpl(A) {}
116 Attribute() : pImpl(0) {}
118 //===--------------------------------------------------------------------===//
119 // Attribute Construction
120 //===--------------------------------------------------------------------===//
122 /// \brief Return a uniquified Attribute object.
123 static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
124 static Attribute get(LLVMContext &Context, StringRef Kind,
125 StringRef Val = StringRef());
127 /// \brief Return a uniquified Attribute object that has the specific
129 static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
130 static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
132 //===--------------------------------------------------------------------===//
133 // Attribute Accessors
134 //===--------------------------------------------------------------------===//
136 /// \brief Return true if the attribute is an Attribute::AttrKind type.
137 bool isEnumAttribute() const;
139 /// \brief Return true if the attribute is an alignment attribute.
140 bool isAlignAttribute() const;
142 /// \brief Return true if the attribute is a string (target-dependent)
144 bool isStringAttribute() const;
146 /// \brief Return true if the attribute is present.
147 bool hasAttribute(AttrKind Val) const;
149 /// \brief Return true if the target-dependent attribute is present.
150 bool hasAttribute(StringRef Val) const;
152 /// \brief Return the attribute's kind as an enum (Attribute::AttrKind). This
153 /// requires the attribute to be an enum or alignment attribute.
154 Attribute::AttrKind getKindAsEnum() const;
156 /// \brief Return the attribute's value as an integer. This requires that the
157 /// attribute be an alignment attribute.
158 uint64_t getValueAsInt() const;
160 /// \brief Return the attribute's kind as a string. This requires the
161 /// attribute to be a string attribute.
162 StringRef getKindAsString() const;
164 /// \brief Return the attribute's value as a string. This requires the
165 /// attribute to be a string attribute.
166 StringRef getValueAsString() const;
168 /// \brief Returns the alignment field of an attribute as a byte alignment
170 unsigned getAlignment() const;
172 /// \brief Returns the stack alignment field of an attribute as a byte
174 unsigned getStackAlignment() const;
176 /// \brief The Attribute is converted to a string of equivalent mnemonic. This
177 /// is, presumably, for writing out the mnemonics for the assembly writer.
178 std::string getAsString(bool InAttrGrp = false) const;
180 /// \brief Equality and non-equality operators.
181 bool operator==(Attribute A) const { return pImpl == A.pImpl; }
182 bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
184 /// \brief Less-than operator. Useful for sorting the attributes list.
185 bool operator<(Attribute A) const;
187 void Profile(FoldingSetNodeID &ID) const {
188 ID.AddPointer(pImpl);
192 //===----------------------------------------------------------------------===//
194 /// \brief This class holds the attributes for a function, its return value, and
195 /// its parameters. You access the attributes for each of them via an index into
196 /// the AttributeSet object. The function attributes are at index
197 /// `AttributeSet::FunctionIndex', the return value is at index
198 /// `AttributeSet::ReturnIndex', and the attributes for the parameters start at
207 friend class AttrBuilder;
208 friend class AttributeSetImpl;
209 template <typename Ty> friend struct DenseMapInfo;
211 /// \brief The attributes that we are managing. This can be null to represent
212 /// the empty attributes list.
213 AttributeSetImpl *pImpl;
215 /// \brief The attributes for the specified index are returned.
216 AttributeSetNode *getAttributes(unsigned Index) const;
218 /// \brief Create an AttributeSet with the specified parameters in it.
219 static AttributeSet get(LLVMContext &C,
220 ArrayRef<std::pair<unsigned, Attribute> > Attrs);
221 static AttributeSet get(LLVMContext &C,
222 ArrayRef<std::pair<unsigned,
223 AttributeSetNode*> > Attrs);
225 static AttributeSet getImpl(LLVMContext &C,
226 ArrayRef<std::pair<unsigned,
227 AttributeSetNode*> > Attrs);
230 explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
232 AttributeSet() : pImpl(0) {}
234 //===--------------------------------------------------------------------===//
235 // AttributeSet Construction and Mutation
236 //===--------------------------------------------------------------------===//
238 /// \brief Return an AttributeSet with the specified parameters in it.
239 static AttributeSet get(LLVMContext &C, ArrayRef<AttributeSet> Attrs);
240 static AttributeSet get(LLVMContext &C, unsigned Index,
241 ArrayRef<Attribute::AttrKind> Kind);
242 static AttributeSet get(LLVMContext &C, unsigned Index, AttrBuilder &B);
244 /// \brief Add an attribute to the attribute set at the given index. Since
245 /// attribute sets are immutable, this returns a new set.
246 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
247 Attribute::AttrKind Attr) const;
249 /// \brief Add an attribute to the attribute set at the given index. Since
250 /// attribute sets are immutable, this returns a new set.
251 AttributeSet addAttribute(LLVMContext &C, unsigned Index,
252 StringRef Kind) const;
254 /// \brief Add attributes to the attribute set at the given index. Since
255 /// attribute sets are immutable, this returns a new set.
256 AttributeSet addAttributes(LLVMContext &C, unsigned Index,
257 AttributeSet Attrs) const;
259 /// \brief Remove the specified attribute at the specified index from this
260 /// attribute list. Since attribute lists are immutable, this returns the new
262 AttributeSet removeAttribute(LLVMContext &C, unsigned Index,
263 Attribute::AttrKind Attr) const;
265 /// \brief Remove the specified attributes at the specified index from this
266 /// attribute list. Since attribute lists are immutable, this returns the new
268 AttributeSet removeAttributes(LLVMContext &C, unsigned Index,
269 AttributeSet Attrs) const;
271 //===--------------------------------------------------------------------===//
272 // AttributeSet Accessors
273 //===--------------------------------------------------------------------===//
275 /// \brief Retrieve the LLVM context.
276 LLVMContext &getContext() const;
278 /// \brief The attributes for the specified index are returned.
279 AttributeSet getParamAttributes(unsigned Index) const;
281 /// \brief The attributes for the ret value are returned.
282 AttributeSet getRetAttributes() const;
284 /// \brief The function attributes are returned.
285 AttributeSet getFnAttributes() const;
287 /// \brief Return true if the attribute exists at the given index.
288 bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
290 /// \brief Return true if the attribute exists at the given index.
291 bool hasAttribute(unsigned Index, StringRef Kind) const;
293 /// \brief Return true if attribute exists at the given index.
294 bool hasAttributes(unsigned Index) const;
296 /// \brief Return true if the specified attribute is set for at least one
297 /// parameter or for the return value.
298 bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
300 /// \brief Return the attribute object that exists at the given index.
301 Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const;
303 /// \brief Return the attribute object that exists at the given index.
304 Attribute getAttribute(unsigned Index, StringRef Kind) const;
306 /// \brief Return the alignment for the specified function parameter.
307 unsigned getParamAlignment(unsigned Index) const;
309 /// \brief Get the stack alignment.
310 unsigned getStackAlignment(unsigned Index) const;
312 /// \brief Return the attributes at the index as a string.
313 std::string getAsString(unsigned Index, bool InAttrGrp = false) const;
315 typedef ArrayRef<Attribute>::iterator iterator;
317 iterator begin(unsigned Slot) const;
318 iterator end(unsigned Slot) const;
320 /// operator==/!= - Provide equality predicates.
321 bool operator==(const AttributeSet &RHS) const {
322 return pImpl == RHS.pImpl;
324 bool operator!=(const AttributeSet &RHS) const {
325 return pImpl != RHS.pImpl;
328 //===--------------------------------------------------------------------===//
329 // AttributeSet Introspection
330 //===--------------------------------------------------------------------===//
332 // FIXME: Remove this.
333 uint64_t Raw(unsigned Index) const;
335 /// \brief Return a raw pointer that uniquely identifies this attribute list.
336 void *getRawPointer() const {
340 /// \brief Return true if there are no attributes.
341 bool isEmpty() const {
342 return getNumSlots() == 0;
345 /// \brief Return the number of slots used in this attribute list. This is
346 /// the number of arguments that have an attribute set on them (including the
347 /// function itself).
348 unsigned getNumSlots() const;
350 /// \brief Return the index for the given slot.
351 unsigned getSlotIndex(unsigned Slot) const;
353 /// \brief Return the attributes at the given slot.
354 AttributeSet getSlotAttributes(unsigned Slot) const;
359 //===----------------------------------------------------------------------===//
361 /// \brief Provide DenseMapInfo for AttributeSet.
362 template<> struct DenseMapInfo<AttributeSet> {
363 static inline AttributeSet getEmptyKey() {
364 uintptr_t Val = static_cast<uintptr_t>(-1);
365 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
366 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
368 static inline AttributeSet getTombstoneKey() {
369 uintptr_t Val = static_cast<uintptr_t>(-2);
370 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
371 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
373 static unsigned getHashValue(AttributeSet AS) {
374 return (unsigned((uintptr_t)AS.pImpl) >> 4) ^
375 (unsigned((uintptr_t)AS.pImpl) >> 9);
377 static bool isEqual(AttributeSet LHS, AttributeSet RHS) { return LHS == RHS; }
380 //===----------------------------------------------------------------------===//
382 /// \brief This class is used in conjunction with the Attribute::get method to
383 /// create an Attribute object. The object itself is uniquified. The Builder's
384 /// value, however, is not. So this can be used as a quick way to test for
385 /// equality, presence of attributes, etc.
387 std::bitset<Attribute::EndAttrKinds> Attrs;
388 std::map<std::string, std::string> TargetDepAttrs;
390 uint64_t StackAlignment;
392 AttrBuilder() : Attrs(0), Alignment(0), StackAlignment(0) {}
393 explicit AttrBuilder(uint64_t Val)
394 : Attrs(0), Alignment(0), StackAlignment(0) {
397 AttrBuilder(const Attribute &A) : Attrs(0), Alignment(0), StackAlignment(0) {
400 AttrBuilder(AttributeSet AS, unsigned Idx);
401 AttrBuilder(const AttrBuilder &B)
403 TargetDepAttrs(B.TargetDepAttrs.begin(), B.TargetDepAttrs.end()),
404 Alignment(B.Alignment), StackAlignment(B.StackAlignment) {}
408 /// \brief Add an attribute to the builder.
409 AttrBuilder &addAttribute(Attribute::AttrKind Val);
411 /// \brief Add the Attribute object to the builder.
412 AttrBuilder &addAttribute(Attribute A);
414 /// \brief Add the target-dependent attribute to the builder.
415 AttrBuilder &addAttribute(StringRef A, StringRef V = StringRef());
417 /// \brief Remove an attribute from the builder.
418 AttrBuilder &removeAttribute(Attribute::AttrKind Val);
420 /// \brief Remove the attributes from the builder.
421 AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
423 /// \brief Remove the target-dependent attribute to the builder.
424 AttrBuilder &removeAttribute(StringRef A);
426 /// \brief Add the attributes from the builder.
427 AttrBuilder &merge(const AttrBuilder &B);
429 /// \brief Return true if the builder has the specified attribute.
430 bool contains(Attribute::AttrKind A) const {
431 assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
435 /// \brief Return true if the builder has the specified target-dependent
437 bool contains(StringRef A) const;
439 /// \brief Return true if the builder has IR-level attributes.
440 bool hasAttributes() const;
442 /// \brief Return true if the builder has any attribute that's in the
443 /// specified attribute.
444 bool hasAttributes(AttributeSet A, uint64_t Index) const;
446 /// \brief Return true if the builder has an alignment attribute.
447 bool hasAlignmentAttr() const;
449 /// \brief Retrieve the alignment attribute, if it exists.
450 uint64_t getAlignment() const { return Alignment; }
452 /// \brief Retrieve the stack alignment attribute, if it exists.
453 uint64_t getStackAlignment() const { return StackAlignment; }
455 /// \brief This turns an int alignment (which must be a power of 2) into the
456 /// form used internally in Attribute.
457 AttrBuilder &addAlignmentAttr(unsigned Align);
459 /// \brief This turns an int stack alignment (which must be a power of 2) into
460 /// the form used internally in Attribute.
461 AttrBuilder &addStackAlignmentAttr(unsigned Align);
463 /// \brief Return true if the builder contains no target-independent
465 bool empty() const { return Attrs.none(); }
467 // Iterators for target-dependent attributes.
468 typedef std::pair<std::string, std::string> td_type;
469 typedef std::map<std::string, std::string>::iterator td_iterator;
470 typedef std::map<std::string, std::string>::const_iterator td_const_iterator;
472 td_iterator td_begin() { return TargetDepAttrs.begin(); }
473 td_iterator td_end() { return TargetDepAttrs.end(); }
475 td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
476 td_const_iterator td_end() const { return TargetDepAttrs.end(); }
478 bool td_empty() const { return TargetDepAttrs.empty(); }
480 bool operator==(const AttrBuilder &B);
481 bool operator!=(const AttrBuilder &B) {
482 return !(*this == B);
485 // FIXME: Remove this in 4.0.
487 /// \brief Add the raw value to the internal representation.
488 AttrBuilder &addRawValue(uint64_t Val);
491 namespace AttributeFuncs {
493 /// \brief Which attributes cannot be applied to a type.
494 AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
496 } // end AttributeFuncs namespace
498 } // end llvm namespace