1 //===-- llvm/Attributes.h - Container for ParamAttrs ---*- 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 //===----------------------------------------------------------------------===//
10 // This file contains the simple types necessary to represent the parameter
11 // attributes associated with functions and their calls.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_PARAMETER_ATTRIBUTES_H
16 #define LLVM_PARAMETER_ATTRIBUTES_H
23 /// Attributes - A bitset of attributes for a parameter.
24 typedef unsigned Attributes;
28 /// Function parameters and results can have attributes to indicate how they
29 /// should be treated by optimizations and code generation. This enumeration
30 /// lists the attributes that can be associated with parameters or function
32 /// @brief Function parameter attributes.
34 const Attributes None = 0; ///< No attributes have been set
35 const Attributes ZExt = 1<<0; ///< Zero extended before/after call
36 const Attributes SExt = 1<<1; ///< Sign extended before/after call
37 const Attributes NoReturn = 1<<2; ///< Mark the function as not returning
38 const Attributes InReg = 1<<3; ///< Force argument to be passed in register
39 const Attributes StructRet = 1<<4; ///< Hidden pointer to structure to return
40 const Attributes NoUnwind = 1<<5; ///< Function doesn't unwind stack
41 const Attributes NoAlias = 1<<6; ///< Considered to not alias after call
42 const Attributes ByVal = 1<<7; ///< Pass structure by value
43 const Attributes Nest = 1<<8; ///< Nested function static chain
44 const Attributes ReadNone = 1<<9; ///< Function does not access memory
45 const Attributes ReadOnly = 1<<10; ///< Function only reads from memory
46 const Attributes Alignment = 0xffff<<16; ///< Alignment of parameter (16 bits)
47 // 0 = unknown, else in clear (not log)
49 /// Function notes are implemented as attributes stored at index ~0 in
50 /// parameter attribute list.
51 const Attributes FN_NOTE_None = 0;
52 const Attributes FN_NOTE_NoInline = 1<<0; // inline=never
53 const Attributes FN_NOTE_AlwaysInline = 1<<1; // inline=always
54 const Attributes FN_NOTE_OptimizeForSize = 1<<2; // opt_size
56 /// @brief Attributes that only apply to function parameters.
57 const Attributes ParameterOnly = ByVal | Nest | StructRet;
59 /// @brief Attributes that only apply to function return values.
60 const Attributes ReturnOnly = NoReturn | NoUnwind | ReadNone | ReadOnly;
62 /// @brief Parameter attributes that do not apply to vararg call arguments.
63 const Attributes VarArgsIncompatible = StructRet;
65 /// @brief Attributes that are mutually incompatible.
66 const Attributes MutuallyIncompatible[3] = {
67 ByVal | InReg | Nest | StructRet,
72 /// @brief Which attributes cannot be applied to a type.
73 Attributes typeIncompatible(const Type *Ty);
75 /// This turns an int alignment (a power of 2, normally) into the
76 /// form used internally in Attributes.
77 inline Attributes constructAlignmentFromInt(unsigned i) {
81 /// The set of Attributes set in Attributes is converted to a
82 /// string of equivalent mnemonics. This is, presumably, for writing out
83 /// the mnemonics for the assembly writer.
84 /// @brief Convert parameter attribute bits to text
85 std::string getAsString(Attributes Attrs);
86 } // end namespace ParamAttr
89 /// This is just a pair of values to associate a set of parameter attributes
90 /// with a parameter index.
91 struct ParamAttrsWithIndex {
92 Attributes Attrs; ///< The attributes that are set, or'd together.
93 unsigned Index; ///< Index of the parameter for which the attributes apply.
95 static ParamAttrsWithIndex get(unsigned Idx, Attributes Attrs) {
96 ParamAttrsWithIndex P;
103 //===----------------------------------------------------------------------===//
104 // PAListPtr Smart Pointer
105 //===----------------------------------------------------------------------===//
107 class ParamAttributeListImpl;
109 /// PAListPtr - This class manages the ref count for the opaque
110 /// ParamAttributeListImpl object and provides accessors for it.
112 /// PAList - The parameter attributes that we are managing. This can be null
113 /// to represent the empty parameter attributes list.
114 ParamAttributeListImpl *PAList;
116 PAListPtr() : PAList(0) {}
117 PAListPtr(const PAListPtr &P);
118 const PAListPtr &operator=(const PAListPtr &RHS);
121 //===--------------------------------------------------------------------===//
122 // Parameter Attribute List Construction and Mutation
123 //===--------------------------------------------------------------------===//
125 /// get - Return a ParamAttrs list with the specified parameter in it.
126 static PAListPtr get(const ParamAttrsWithIndex *Attr, unsigned NumAttrs);
128 /// get - Return a ParamAttr list with the parameters specified by the
129 /// consecutive random access iterator range.
130 template <typename Iter>
131 static PAListPtr get(const Iter &I, const Iter &E) {
132 if (I == E) return PAListPtr(); // Empty list.
133 return get(&*I, static_cast<unsigned>(E-I));
136 /// addAttr - Add the specified attribute at the specified index to this
137 /// attribute list. Since parameter attribute lists are immutable, this
138 /// returns the new list.
139 PAListPtr addAttr(unsigned Idx, Attributes Attrs) const;
141 /// removeAttr - Remove the specified attribute at the specified index from
142 /// this attribute list. Since parameter attribute lists are immutable, this
143 /// returns the new list.
144 PAListPtr removeAttr(unsigned Idx, Attributes Attrs) const;
146 //===--------------------------------------------------------------------===//
147 // Parameter Attribute List Accessors
148 //===--------------------------------------------------------------------===//
150 /// getParamAttrs - The parameter attributes for the specified parameter are
151 /// returned. Parameters for the result are denoted with Idx = 0.
152 Attributes getParamAttrs(unsigned Idx) const;
154 /// paramHasAttr - Return true if the specified parameter index has the
155 /// specified attribute set.
156 bool paramHasAttr(unsigned Idx, Attributes Attr) const {
157 return getParamAttrs(Idx) & Attr;
160 /// getParamAlignment - Return the alignment for the specified function
162 unsigned getParamAlignment(unsigned Idx) const {
163 return (getParamAttrs(Idx) & ParamAttr::Alignment) >> 16;
166 /// hasAttrSomewhere - Return true if the specified attribute is set for at
167 /// least one parameter or for the return value.
168 bool hasAttrSomewhere(Attributes Attr) const;
170 /// operator==/!= - Provide equality predicates.
171 bool operator==(const PAListPtr &RHS) const { return PAList == RHS.PAList; }
172 bool operator!=(const PAListPtr &RHS) const { return PAList != RHS.PAList; }
176 //===--------------------------------------------------------------------===//
177 // Parameter Attribute List Introspection
178 //===--------------------------------------------------------------------===//
180 /// getRawPointer - Return a raw pointer that uniquely identifies this
181 /// parameter attribute list.
182 void *getRawPointer() const {
186 // Parameter attributes are stored as a dense set of slots, where there is one
187 // slot for each argument that has an attribute. This allows walking over the
188 // dense set instead of walking the sparse list of attributes.
190 /// isEmpty - Return true if no parameters have an attribute.
192 bool isEmpty() const {
196 /// getNumSlots - Return the number of slots used in this attribute list.
197 /// This is the number of arguments that have an attribute set on them
198 /// (including the function itself).
199 unsigned getNumSlots() const;
201 /// getSlot - Return the ParamAttrsWithIndex at the specified slot. This
202 /// holds a parameter number plus a set of attributes.
203 const ParamAttrsWithIndex &getSlot(unsigned Slot) const;
206 explicit PAListPtr(ParamAttributeListImpl *L);
209 } // End llvm namespace