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 InlineHint, ///< Source said inlining was desirable
72 InReg, ///< Force argument to be passed in register
73 MinSize, ///< Function must be optimized for size first
74 Naked, ///< Naked function
75 Nest, ///< Nested function static chain
76 NoAlias, ///< Considered to not alias after call
77 NoBuiltin, ///< Callee isn't recognized as a builtin
78 NoCapture, ///< Function creates no aliases of pointer
79 NoDuplicate, ///< Call cannot be duplicated
80 NoImplicitFloat, ///< Disable implicit floating point insts
81 NoInline, ///< inline=never
82 NonLazyBind, ///< Function is called early and/or
83 ///< often, so lazy binding isn't worthwhile
84 NoRedZone, ///< Disable redzone
85 NoReturn, ///< Mark the function as not returning
86 NoUnwind, ///< Function doesn't unwind stack
87 OptimizeForSize, ///< opt_size
88 ReadNone, ///< Function does not access memory
89 ReadOnly, ///< Function only reads from memory
90 ReturnsTwice, ///< Function can return twice
91 SExt, ///< Sign extended before/after call
92 StackAlignment, ///< Alignment of stack for function (3 bits)
93 ///< stored as log2 of alignment with +1 bias 0
94 ///< means unaligned (different from
96 StackProtect, ///< Stack protection.
97 StackProtectReq, ///< Stack protection required.
98 StackProtectStrong, ///< Strong Stack protection.
99 StructRet, ///< Hidden pointer to structure to return
100 SanitizeAddress, ///< AddressSanitizer is on.
101 SanitizeThread, ///< ThreadSanitizer is on.
102 SanitizeMemory, ///< MemorySanitizer is on.
103 UWTable, ///< Function must be in a unwind table
104 ZExt, ///< Zero extended before/after call
106 EndAttrKinds ///< Sentinal value useful for loops
109 AttributeImpl *pImpl;
110 Attribute(AttributeImpl *A) : pImpl(A) {}
112 Attribute() : pImpl(0) {}
114 //===--------------------------------------------------------------------===//
115 // Attribute Construction
116 //===--------------------------------------------------------------------===//
118 /// \brief Return a uniquified Attribute object.
119 static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
120 static Attribute get(LLVMContext &Context, StringRef Kind,
121 StringRef Val = StringRef());
123 /// \brief Return a uniquified Attribute object that has the specific
125 static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
126 static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
128 //===--------------------------------------------------------------------===//
129 // Attribute Accessors
130 //===--------------------------------------------------------------------===//
132 /// \brief Return true if the attribute is an Attribute::AttrKind type.
133 bool isEnumAttribute() const;
135 /// \brief Return true if the attribute is an alignment attribute.
136 bool isAlignAttribute() const;
138 /// \brief Return true if the attribute is a string (target-dependent)
140 bool isStringAttribute() const;
142 /// \brief Return true if the attribute is present.
143 bool hasAttribute(AttrKind Val) const;
145 /// \brief Return true if the target-dependent attribute is present.
146 bool hasAttribute(StringRef Val) const;
148 /// \brief Return the attribute's kind as an enum (Attribute::AttrKind). This
149 /// requires the attribute to be an enum or alignment attribute.
150 Attribute::AttrKind getKindAsEnum() const;
152 /// \brief Return the attribute's value as an integer. This requires that the
153 /// attribute be an alignment attribute.
154 uint64_t getValueAsInt() const;
156 /// \brief Return the attribute's kind as a string. This requires the
157 /// attribute to be a string attribute.
158 StringRef getKindAsString() const;
160 /// \brief Return the attribute's value as a string. This requires the
161 /// attribute to be a string attribute.
162 StringRef getValueAsString() const;
164 /// \brief Returns the alignment field of an attribute as a byte alignment
166 unsigned getAlignment() const;
168 /// \brief Returns the stack alignment field of an attribute as a byte
170 unsigned getStackAlignment() const;
172 /// \brief The Attribute is converted to a string of equivalent mnemonic. This
173 /// is, presumably, for writing out the mnemonics for the assembly writer.
174 std::string getAsString(bool InAttrGrp = false) const;
176 /// \brief Equality and non-equality operators.
177 bool operator==(Attribute A) const { return pImpl == A.pImpl; }
178 bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
180 /// \brief Less-than operator. Useful for sorting the attributes list.
181 bool operator<(Attribute A) const;
183 void Profile(FoldingSetNodeID &ID) const {
184 ID.AddPointer(pImpl);
188 //===----------------------------------------------------------------------===//
190 /// \brief This class holds the attributes for a function, its return value, and
191 /// its parameters. You access the attributes for each of them via an index into
192 /// the AttributeSet object. The function attributes are at index
193 /// `AttributeSet::FunctionIndex', the return value is at index
194 /// `AttributeSet::ReturnIndex', and the attributes for the parameters start at
203 friend class AttrBuilder;
204 friend class AttributeSetImpl;
205 template <typename Ty> friend struct DenseMapInfo;
207 /// \brief The attributes that we are managing. This can be null to represent
208 /// the empty attributes list.
209 AttributeSetImpl *pImpl;
211 /// \brief The attributes for the specified index are returned.
212 AttributeSetNode *getAttributes(unsigned Idx) const;
214 /// \brief Create an AttributeSet with the specified parameters in it.
215 static AttributeSet get(LLVMContext &C,
216 ArrayRef<std::pair<unsigned, Attribute> > Attrs);
217 static AttributeSet get(LLVMContext &C,
218 ArrayRef<std::pair<unsigned,
219 AttributeSetNode*> > Attrs);
221 static AttributeSet getImpl(LLVMContext &C,
222 ArrayRef<std::pair<unsigned,
223 AttributeSetNode*> > Attrs);
226 explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
228 AttributeSet() : pImpl(0) {}
229 AttributeSet(const AttributeSet &P) : pImpl(P.pImpl) {}
230 const AttributeSet &operator=(const AttributeSet &RHS) {
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 Idx,
242 ArrayRef<Attribute::AttrKind> Kind);
243 static AttributeSet get(LLVMContext &C, unsigned Idx, 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 Idx,
248 Attribute::AttrKind Attr) const;
250 /// \brief Add attributes to the attribute set at the given index. Since
251 /// attribute sets are immutable, this returns a new set.
252 AttributeSet addAttributes(LLVMContext &C, unsigned Idx,
253 AttributeSet Attrs) const;
255 /// \brief Remove the specified attribute at the specified index from this
256 /// attribute list. Since attribute lists are immutable, this returns the new
258 AttributeSet removeAttribute(LLVMContext &C, unsigned Idx,
259 Attribute::AttrKind Attr) const;
261 /// \brief Remove the specified attributes at the specified index from this
262 /// attribute list. Since attribute lists are immutable, this returns the new
264 AttributeSet removeAttributes(LLVMContext &C, unsigned Idx,
265 AttributeSet Attrs) const;
267 //===--------------------------------------------------------------------===//
268 // AttributeSet Accessors
269 //===--------------------------------------------------------------------===//
271 /// \brief Retrieve the LLVM context.
272 LLVMContext &getContext() const;
274 /// \brief The attributes for the specified index are returned.
275 AttributeSet getParamAttributes(unsigned Idx) const;
277 /// \brief The attributes for the ret value are returned.
278 AttributeSet getRetAttributes() const;
280 /// \brief The function attributes are returned.
281 AttributeSet getFnAttributes() const;
283 /// \brief Return true if the attribute exists at the given index.
284 bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
286 /// \brief Return true if the attribute exists at the given index.
287 bool hasAttribute(unsigned Index, StringRef Kind) const;
289 /// \brief Return true if attribute exists at the given index.
290 bool hasAttributes(unsigned Index) const;
292 /// \brief Return true if the specified attribute is set for at least one
293 /// parameter or for the return value.
294 bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
296 /// \brief Return the attribute object that exists at the given index.
297 Attribute getAttribute(unsigned Index, Attribute::AttrKind Kind) const;
299 /// \brief Return the attribute object that exists at the given index.
300 Attribute getAttribute(unsigned Index, StringRef Kind) const;
302 /// \brief Return the alignment for the specified function parameter.
303 unsigned getParamAlignment(unsigned Idx) const;
305 /// \brief Get the stack alignment.
306 unsigned getStackAlignment(unsigned Index) const;
308 /// \brief Return the attributes at the index as a string.
309 std::string getAsString(unsigned Index, bool InAttrGrp = false) const;
311 typedef ArrayRef<Attribute>::iterator iterator;
313 iterator begin(unsigned Idx) const;
314 iterator end(unsigned Idx) const;
316 /// operator==/!= - Provide equality predicates.
317 bool operator==(const AttributeSet &RHS) const {
318 return pImpl == RHS.pImpl;
320 bool operator!=(const AttributeSet &RHS) const {
321 return pImpl != RHS.pImpl;
324 //===--------------------------------------------------------------------===//
325 // AttributeSet Introspection
326 //===--------------------------------------------------------------------===//
328 // FIXME: Remove this.
329 uint64_t Raw(unsigned Index) const;
331 /// \brief Return a raw pointer that uniquely identifies this attribute list.
332 void *getRawPointer() const {
336 /// \brief Return true if there are no attributes.
337 bool isEmpty() const {
338 return getNumSlots() == 0;
341 /// \brief Return the number of slots used in this attribute list. This is
342 /// the number of arguments that have an attribute set on them (including the
343 /// function itself).
344 unsigned getNumSlots() const;
346 /// \brief Return the index for the given slot.
347 uint64_t getSlotIndex(unsigned Slot) const;
349 /// \brief Return the attributes at the given slot.
350 AttributeSet getSlotAttributes(unsigned Slot) const;
355 //===----------------------------------------------------------------------===//
357 /// \brief Provide DenseMapInfo for AttributeSet.
358 template<> struct DenseMapInfo<AttributeSet> {
359 static inline AttributeSet getEmptyKey() {
360 uintptr_t Val = static_cast<uintptr_t>(-1);
361 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
362 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
364 static inline AttributeSet getTombstoneKey() {
365 uintptr_t Val = static_cast<uintptr_t>(-2);
366 Val <<= PointerLikeTypeTraits<void*>::NumLowBitsAvailable;
367 return AttributeSet(reinterpret_cast<AttributeSetImpl*>(Val));
369 static unsigned getHashValue(AttributeSet AS) {
370 return (unsigned((uintptr_t)AS.pImpl) >> 4) ^
371 (unsigned((uintptr_t)AS.pImpl) >> 9);
373 static bool isEqual(AttributeSet LHS, AttributeSet RHS) { return LHS == RHS; }
376 //===----------------------------------------------------------------------===//
378 /// \brief This class is used in conjunction with the Attribute::get method to
379 /// create an Attribute object. The object itself is uniquified. The Builder's
380 /// value, however, is not. So this can be used as a quick way to test for
381 /// equality, presence of attributes, etc.
383 std::bitset<Attribute::EndAttrKinds> Attrs;
384 std::map<std::string, std::string> TargetDepAttrs;
386 uint64_t StackAlignment;
388 AttrBuilder() : Attrs(0), Alignment(0), StackAlignment(0) {}
389 explicit AttrBuilder(uint64_t Val)
390 : Attrs(0), Alignment(0), StackAlignment(0) {
393 AttrBuilder(const Attribute &A) : Attrs(0), Alignment(0), StackAlignment(0) {
396 AttrBuilder(AttributeSet AS, unsigned Idx);
397 AttrBuilder(const AttrBuilder &B)
399 TargetDepAttrs(B.TargetDepAttrs.begin(), B.TargetDepAttrs.end()),
400 Alignment(B.Alignment), StackAlignment(B.StackAlignment) {}
404 /// \brief Add an attribute to the builder.
405 AttrBuilder &addAttribute(Attribute::AttrKind Val);
407 /// \brief Add the Attribute object to the builder.
408 AttrBuilder &addAttribute(Attribute A);
410 /// \brief Add the target-dependent attribute to the builder.
411 AttrBuilder &addAttribute(StringRef A, StringRef V = StringRef());
413 /// \brief Remove an attribute from the builder.
414 AttrBuilder &removeAttribute(Attribute::AttrKind Val);
416 /// \brief Remove the attributes from the builder.
417 AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
419 /// \brief Remove the target-dependent attribute to the builder.
420 AttrBuilder &removeAttribute(StringRef A);
422 /// \brief Add the attributes from the builder.
423 AttrBuilder &merge(const AttrBuilder &B);
425 /// \brief Return true if the builder has the specified attribute.
426 bool contains(Attribute::AttrKind A) const {
427 assert((unsigned)A < Attribute::EndAttrKinds && "Attribute out of range!");
431 /// \brief Return true if the builder has the specified target-dependent
433 bool contains(StringRef A) const;
435 /// \brief Return true if the builder has IR-level attributes.
436 bool hasAttributes() const;
438 /// \brief Return true if the builder has any attribute that's in the
439 /// specified attribute.
440 bool hasAttributes(AttributeSet A, uint64_t Index) const;
442 /// \brief Return true if the builder has an alignment attribute.
443 bool hasAlignmentAttr() const;
445 /// \brief Retrieve the alignment attribute, if it exists.
446 uint64_t getAlignment() const { return Alignment; }
448 /// \brief Retrieve the stack alignment attribute, if it exists.
449 uint64_t getStackAlignment() const { return StackAlignment; }
451 /// \brief This turns an int alignment (which must be a power of 2) into the
452 /// form used internally in Attribute.
453 AttrBuilder &addAlignmentAttr(unsigned Align);
455 /// \brief This turns an int stack alignment (which must be a power of 2) into
456 /// the form used internally in Attribute.
457 AttrBuilder &addStackAlignmentAttr(unsigned Align);
459 /// \brief Return true if the builder contains no target-independent
461 bool empty() const { return Attrs.none(); }
463 // Iterators for target-dependent attributes.
464 typedef std::pair<std::string, std::string> td_type;
465 typedef std::map<std::string, std::string>::iterator td_iterator;
466 typedef std::map<std::string, std::string>::const_iterator td_const_iterator;
468 td_iterator td_begin() { return TargetDepAttrs.begin(); }
469 td_iterator td_end() { return TargetDepAttrs.end(); }
471 td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
472 td_const_iterator td_end() const { return TargetDepAttrs.end(); }
474 bool td_empty() const { return TargetDepAttrs.empty(); }
476 /// \brief Remove attributes that are used on functions only.
477 void removeFunctionOnlyAttrs();
479 bool operator==(const AttrBuilder &B);
480 bool operator!=(const AttrBuilder &B) {
481 return !(*this == B);
484 // FIXME: Remove this in 4.0.
486 /// \brief Add the raw value to the internal representation.
487 AttrBuilder &addRawValue(uint64_t Val);
490 namespace AttributeFuncs {
492 /// \brief Which attributes cannot be applied to a type.
493 AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
495 } // end AttributeFuncs namespace
497 } // end llvm namespace