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/DenseSet.h"
21 #include "llvm/ADT/FoldingSet.h"
30 class AttributeSetImpl;
31 class AttributeSetNode;
36 //===----------------------------------------------------------------------===//
38 /// \brief Functions, function parameters, and return types can have attributes
39 /// to indicate how they should be treated by optimizations and code
40 /// generation. This class represents one of those attributes. It's light-weight
41 /// and should be passed around by-value.
44 /// This enumeration lists the attributes that can be associated with
45 /// parameters, function results, or the function itself.
47 /// Note: The `uwtable' attribute is about the ABI or the user mandating an
48 /// entry in the unwind table. The `nounwind' attribute is about an exception
49 /// passing by the function.
51 /// In a theoretical system that uses tables for profiling and SjLj for
52 /// exceptions, they would be fully independent. In a normal system that uses
53 /// tables for both, the semantics are:
55 /// nil = Needs an entry because an exception might pass by.
56 /// nounwind = No need for an entry
57 /// uwtable = Needs an entry because the ABI says so and because
58 /// an exception might pass by.
59 /// uwtable + nounwind = Needs an entry because the ABI says so.
62 // IR-Level Attributes
63 None, ///< No attributes have been set
64 AddressSafety, ///< Address safety checking is on.
65 Alignment, ///< Alignment of parameter (5 bits)
66 ///< stored as log2 of alignment with +1 bias
67 ///< 0 means unaligned (different from align(1))
68 AlwaysInline, ///< inline=always
69 ByVal, ///< Pass structure by value
70 InlineHint, ///< Source said inlining was desirable
71 InReg, ///< Force argument to be passed in register
72 MinSize, ///< Function must be optimized for size first
73 Naked, ///< Naked function
74 Nest, ///< Nested function static chain
75 NoAlias, ///< Considered to not alias after call
76 NoCapture, ///< Function creates no aliases of pointer
77 NoDuplicate, ///< Call cannot be duplicated
78 NoImplicitFloat, ///< Disable implicit floating point insts
79 NoInline, ///< inline=never
80 NonLazyBind, ///< Function is called early and/or
81 ///< often, so lazy binding isn't worthwhile
82 NoRedZone, ///< Disable redzone
83 NoReturn, ///< Mark the function as not returning
84 NoUnwind, ///< Function doesn't unwind stack
85 OptimizeForSize, ///< opt_size
86 ReadNone, ///< Function does not access memory
87 ReadOnly, ///< Function only reads from memory
88 ReturnsTwice, ///< Function can return twice
89 SExt, ///< Sign extended before/after call
90 StackAlignment, ///< Alignment of stack for function (3 bits)
91 ///< stored as log2 of alignment with +1 bias 0
92 ///< means unaligned (different from
94 StackProtect, ///< Stack protection.
95 StackProtectReq, ///< Stack protection required.
96 StackProtectStrong, ///< Strong Stack protection.
97 StructRet, ///< Hidden pointer to structure to return
98 UWTable, ///< Function must be in a unwind table
99 ZExt, ///< Zero extended before/after call
101 EndAttrKinds, ///< Sentinal value useful for loops
103 AttrKindEmptyKey, ///< Empty key value for DenseMapInfo
104 AttrKindTombstoneKey ///< Tombstone key value for DenseMapInfo
107 AttributeImpl *pImpl;
108 Attribute(AttributeImpl *A) : pImpl(A) {}
110 Attribute() : pImpl(0) {}
112 //===--------------------------------------------------------------------===//
113 // Attribute Construction
114 //===--------------------------------------------------------------------===//
116 /// \brief Return a uniquified Attribute object.
117 static Attribute get(LLVMContext &Context, AttrKind Kind, uint64_t Val = 0);
118 static Attribute get(LLVMContext &Context, StringRef Kind,
119 StringRef Val = StringRef());
121 /// \brief Return a uniquified Attribute object that has the specific
123 static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
124 static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
126 //===--------------------------------------------------------------------===//
127 // Attribute Accessors
128 //===--------------------------------------------------------------------===//
130 /// \brief Return true if the attribute is an Attribute::AttrKind type.
131 bool isEnumAttribute() const;
133 /// \brief Return true if the attribute is an alignment attribute.
134 bool isAlignAttribute() const;
136 /// \brief Return true if the attribute is a string (target-dependent)
138 bool isStringAttribute() const;
140 /// \brief Return true if the attribute is present.
141 bool hasAttribute(AttrKind Val) const;
143 /// \brief Return true if the target-dependent attribute is present.
144 bool hasAttribute(StringRef Val) const;
146 /// \brief Return the attribute's kind as an enum (Attribute::AttrKind). This
147 /// requires the attribute to be an enum or alignment attribute.
148 Attribute::AttrKind getKindAsEnum() const;
150 /// \brief Return the attribute's value as an integer. This requires that the
151 /// attribute be an alignment attribute.
152 uint64_t getValueAsInt() const;
154 /// \brief Return the attribute's kind as a string. This requires the
155 /// attribute to be a string attribute.
156 StringRef getKindAsString() const;
158 /// \brief Return the attribute's value as a string. This requires the
159 /// attribute to be a string attribute.
160 StringRef getValueAsString() const;
162 /// \brief Returns the alignment field of an attribute as a byte alignment
164 unsigned getAlignment() const;
166 /// \brief Returns the stack alignment field of an attribute as a byte
168 unsigned getStackAlignment() const;
170 /// \brief The Attribute is converted to a string of equivalent mnemonic. This
171 /// is, presumably, for writing out the mnemonics for the assembly writer.
172 std::string getAsString() const;
174 /// \brief Equality and non-equality operators.
175 bool operator==(Attribute A) const { return pImpl == A.pImpl; }
176 bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
178 /// \brief Less-than operator. Useful for sorting the attributes list.
179 bool operator<(Attribute A) const;
181 void Profile(FoldingSetNodeID &ID) const {
182 ID.AddPointer(pImpl);
186 //===----------------------------------------------------------------------===//
188 /// \brief This class manages the ref count for the opaque AttributeSetImpl
189 /// object and provides accessors for it.
197 friend class AttrBuilder;
198 friend class AttributeSetImpl;
200 /// \brief The attributes that we are managing. This can be null to represent
201 /// the empty attributes list.
202 AttributeSetImpl *pImpl;
204 /// \brief The attributes for the specified index are returned.
205 AttributeSetNode *getAttributes(unsigned Idx) const;
207 /// \brief Create an AttributeSet with the specified parameters in it.
208 static AttributeSet get(LLVMContext &C,
209 ArrayRef<std::pair<unsigned, Attribute> > Attrs);
210 static AttributeSet get(LLVMContext &C,
211 ArrayRef<std::pair<unsigned,
212 AttributeSetNode*> > Attrs);
214 static AttributeSet getImpl(LLVMContext &C,
215 ArrayRef<std::pair<unsigned,
216 AttributeSetNode*> > Attrs);
219 explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
221 AttributeSet() : pImpl(0) {}
222 AttributeSet(const AttributeSet &P) : pImpl(P.pImpl) {}
223 const AttributeSet &operator=(const AttributeSet &RHS) {
228 //===--------------------------------------------------------------------===//
229 // AttributeSet Construction and Mutation
230 //===--------------------------------------------------------------------===//
232 /// \brief Return an AttributeSet with the specified parameters in it.
233 static AttributeSet get(LLVMContext &C, ArrayRef<AttributeSet> Attrs);
234 static AttributeSet get(LLVMContext &C, unsigned Idx,
235 ArrayRef<Attribute::AttrKind> Kind);
236 static AttributeSet get(LLVMContext &C, unsigned Idx, AttrBuilder &B);
238 /// \brief Add an attribute to the attribute set at the given index. Since
239 /// attribute sets are immutable, this returns a new set.
240 AttributeSet addAttribute(LLVMContext &C, unsigned Idx,
241 Attribute::AttrKind Attr) const;
243 /// \brief Add attributes to the attribute set at the given index. Since
244 /// attribute sets are immutable, this returns a new set.
245 AttributeSet addAttributes(LLVMContext &C, unsigned Idx,
246 AttributeSet Attrs) const;
248 /// \brief Remove the specified attribute at the specified index from this
249 /// attribute list. Since attribute lists are immutable, this returns the new
251 AttributeSet removeAttribute(LLVMContext &C, unsigned Idx,
252 Attribute::AttrKind Attr) const;
254 /// \brief Remove the specified attributes at the specified index from this
255 /// attribute list. Since attribute lists are immutable, this returns the new
257 AttributeSet removeAttributes(LLVMContext &C, unsigned Idx,
258 AttributeSet Attrs) const;
260 //===--------------------------------------------------------------------===//
261 // AttributeSet Accessors
262 //===--------------------------------------------------------------------===//
264 /// \brief The attributes for the specified index are returned.
265 AttributeSet getParamAttributes(unsigned Idx) const;
267 /// \brief The attributes for the ret value are returned.
268 AttributeSet getRetAttributes() const;
270 /// \brief The function attributes are returned.
271 AttributeSet getFnAttributes() const;
273 /// \brief Return true if the attribute exists at the given index.
274 bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
276 /// \brief Return true if attribute exists at the given index.
277 bool hasAttributes(unsigned Index) const;
279 /// \brief Return true if the specified attribute is set for at least one
280 /// parameter or for the return value.
281 bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
283 /// \brief Return the alignment for the specified function parameter.
284 unsigned getParamAlignment(unsigned Idx) const;
286 /// \brief Get the stack alignment.
287 unsigned getStackAlignment(unsigned Index) const;
289 /// \brief Return the attributes at the index as a string.
290 std::string getAsString(unsigned Index) const;
292 typedef ArrayRef<Attribute>::iterator iterator;
294 iterator begin(unsigned Idx) const;
295 iterator end(unsigned Idx) const;
297 /// operator==/!= - Provide equality predicates.
298 bool operator==(const AttributeSet &RHS) const {
299 return pImpl == RHS.pImpl;
301 bool operator!=(const AttributeSet &RHS) const {
302 return pImpl != RHS.pImpl;
305 //===--------------------------------------------------------------------===//
306 // AttributeSet Introspection
307 //===--------------------------------------------------------------------===//
309 // FIXME: Remove this.
310 uint64_t Raw(unsigned Index) const;
312 /// \brief Return a raw pointer that uniquely identifies this attribute list.
313 void *getRawPointer() const {
317 /// \brief Return true if there are no attributes.
318 bool isEmpty() const {
319 return getNumSlots() == 0;
322 /// \brief Return the number of slots used in this attribute list. This is
323 /// the number of arguments that have an attribute set on them (including the
324 /// function itself).
325 unsigned getNumSlots() const;
327 /// \brief Return the index for the given slot.
328 uint64_t getSlotIndex(unsigned Slot) const;
330 /// \brief Return the attributes at the given slot.
331 AttributeSet getSlotAttributes(unsigned Slot) const;
336 //===----------------------------------------------------------------------===//
338 /// \brief Provide DenseMapInfo for Attribute::AttrKinds. This is used by
340 template<> struct DenseMapInfo<Attribute::AttrKind> {
341 static inline Attribute::AttrKind getEmptyKey() {
342 return Attribute::AttrKindEmptyKey;
344 static inline Attribute::AttrKind getTombstoneKey() {
345 return Attribute::AttrKindTombstoneKey;
347 static unsigned getHashValue(const Attribute::AttrKind &Val) {
350 static bool isEqual(const Attribute::AttrKind &LHS,
351 const Attribute::AttrKind &RHS) {
356 //===----------------------------------------------------------------------===//
358 /// \brief This class is used in conjunction with the Attribute::get method to
359 /// create an Attribute object. The object itself is uniquified. The Builder's
360 /// value, however, is not. So this can be used as a quick way to test for
361 /// equality, presence of attributes, etc.
363 DenseSet<Attribute::AttrKind> Attrs;
364 std::map<std::string, std::string> TargetDepAttrs;
366 uint64_t StackAlignment;
368 AttrBuilder() : Alignment(0), StackAlignment(0) {}
369 explicit AttrBuilder(uint64_t Val) : Alignment(0), StackAlignment(0) {
372 AttrBuilder(const Attribute &A) : Alignment(0), StackAlignment(0) {
375 AttrBuilder(AttributeSet AS, unsigned Idx);
376 AttrBuilder(const AttrBuilder &B)
378 TargetDepAttrs(B.TargetDepAttrs.begin(), B.TargetDepAttrs.end()),
379 Alignment(B.Alignment), StackAlignment(B.StackAlignment) {}
383 /// \brief Add an attribute to the builder.
384 AttrBuilder &addAttribute(Attribute::AttrKind Val);
386 /// \brief Add the Attribute object to the builder.
387 AttrBuilder &addAttribute(Attribute A);
389 /// \brief Add the target-dependent attribute to the builder.
390 AttrBuilder &addAttribute(StringRef A, StringRef V);
392 /// \brief Remove an attribute from the builder.
393 AttrBuilder &removeAttribute(Attribute::AttrKind Val);
395 /// \brief Remove the attributes from the builder.
396 AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
398 /// \brief Remove the target-dependent attribute to the builder.
399 AttrBuilder &removeAttribute(StringRef A);
401 /// \brief Add the attributes from the builder.
402 AttrBuilder &merge(const AttrBuilder &B);
404 /// \brief Return true if the builder has the specified attribute.
405 bool contains(Attribute::AttrKind A) const;
407 /// \brief Return true if the builder has IR-level attributes.
408 bool hasAttributes() const;
410 /// \brief Return true if the builder has any attribute that's in the
411 /// specified attribute.
412 bool hasAttributes(AttributeSet A, uint64_t Index) const;
414 /// \brief Return true if the builder has an alignment attribute.
415 bool hasAlignmentAttr() const;
417 /// \brief Retrieve the alignment attribute, if it exists.
418 uint64_t getAlignment() const { return Alignment; }
420 /// \brief Retrieve the stack alignment attribute, if it exists.
421 uint64_t getStackAlignment() const { return StackAlignment; }
423 /// \brief This turns an int alignment (which must be a power of 2) into the
424 /// form used internally in Attribute.
425 AttrBuilder &addAlignmentAttr(unsigned Align);
427 /// \brief This turns an int stack alignment (which must be a power of 2) into
428 /// the form used internally in Attribute.
429 AttrBuilder &addStackAlignmentAttr(unsigned Align);
431 // Iterators for target-independent attributes.
432 typedef DenseSet<Attribute::AttrKind>::iterator iterator;
433 typedef DenseSet<Attribute::AttrKind>::const_iterator const_iterator;
435 iterator begin() { return Attrs.begin(); }
436 iterator end() { return Attrs.end(); }
438 const_iterator begin() const { return Attrs.begin(); }
439 const_iterator end() const { return Attrs.end(); }
441 // Iterators for target-dependent attributes.
442 typedef std::pair<std::string, std::string> td_type;
443 typedef std::map<std::string, std::string>::iterator td_iterator;
444 typedef std::map<std::string, std::string>::const_iterator td_const_iterator;
446 td_iterator td_begin() { return TargetDepAttrs.begin(); }
447 td_iterator td_end() { return TargetDepAttrs.end(); }
449 td_const_iterator td_begin() const { return TargetDepAttrs.begin(); }
450 td_const_iterator td_end() const { return TargetDepAttrs.end(); }
452 /// \brief Remove attributes that are used on functions only.
453 void removeFunctionOnlyAttrs() {
454 removeAttribute(Attribute::NoReturn)
455 .removeAttribute(Attribute::NoUnwind)
456 .removeAttribute(Attribute::ReadNone)
457 .removeAttribute(Attribute::ReadOnly)
458 .removeAttribute(Attribute::NoInline)
459 .removeAttribute(Attribute::AlwaysInline)
460 .removeAttribute(Attribute::OptimizeForSize)
461 .removeAttribute(Attribute::StackProtect)
462 .removeAttribute(Attribute::StackProtectReq)
463 .removeAttribute(Attribute::StackProtectStrong)
464 .removeAttribute(Attribute::NoRedZone)
465 .removeAttribute(Attribute::NoImplicitFloat)
466 .removeAttribute(Attribute::Naked)
467 .removeAttribute(Attribute::InlineHint)
468 .removeAttribute(Attribute::StackAlignment)
469 .removeAttribute(Attribute::UWTable)
470 .removeAttribute(Attribute::NonLazyBind)
471 .removeAttribute(Attribute::ReturnsTwice)
472 .removeAttribute(Attribute::AddressSafety)
473 .removeAttribute(Attribute::MinSize)
474 .removeAttribute(Attribute::NoDuplicate);
477 bool operator==(const AttrBuilder &B);
478 bool operator!=(const AttrBuilder &B) {
479 return !(*this == B);
482 // FIXME: Remove this in 4.0.
484 /// \brief Add the raw value to the internal representation.
485 AttrBuilder &addRawValue(uint64_t Val);
488 namespace AttributeFuncs {
490 /// \brief Which attributes cannot be applied to a type.
491 AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
493 } // end AttributeFuncs namespace
495 } // end llvm namespace