1 //===-- llvm/ParameterAttributes.h - Container for ParamAttrs ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Reid Spencer and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the types necessary to represent the parameter attributes
11 // associated with functions and their calls.
13 // The implementations of these classes live in lib/VMCore/Function.cpp.
15 //===----------------------------------------------------------------------===//
17 #ifndef LLVM_PARAMETER_ATTRIBUTES_H
18 #define LLVM_PARAMETER_ATTRIBUTES_H
20 #include "llvm/ADT/SmallVector.h"
24 /// Function parameters can have attributes to indicate how they should be
25 /// treated by optimizations and code generation. This enumeration lists the
26 /// attributes that can be associated with parameters or function results.
27 /// @brief Function parameter attributes.
31 None = 0, ///< No attributes have been set
32 ZExt = 1 << 0, ///< zero extended before/after call
33 SExt = 1 << 1, ///< sign extended before/after call
34 NoReturn = 1 << 2, ///< mark the function as not returning
35 InReg = 1 << 3, ///< force argument to be passed in register
36 StructRet = 1 << 4, ///< hidden pointer to structure to return
37 NoUnwind = 1 << 5 ///< Function doesn't unwind stack
42 typedef ParamAttr::Attributes ParameterAttributes;
44 /// This class is used by Function and CallInst to represent the set of
45 /// parameter attributes used. It represents a list of pairs of uint16_t, one
46 /// for the parameter index, and one a set of ParameterAttributes bits.
47 /// Parameters that have no attributes are not present in the list. The list
48 /// may also be empty, but this doesn't occur in practice. The list constructs
49 /// as empty and is filled by the insert method. The list can be turned into
50 /// a string of mnemonics suitable for LLVM Assembly output. Various accessors
51 /// are provided to obtain information about the attributes.
52 /// @brief A List of ParameterAttributes.
53 class ParamAttrsList {
54 //void operator=(const ParamAttrsList &); // Do not implement
55 //ParamAttrsList(const ParamAttrsList &); // Do not implement
60 /// This is an internal structure used to associate the ParameterAttributes
61 /// with a parameter index.
62 /// @brief ParameterAttributes with a parameter index.
63 struct ParamAttrsWithIndex {
64 uint16_t attrs; ///< The attributes that are set, |'d together
65 uint16_t index; ///< Index of the parameter for which the attributes apply
68 /// @brief A vector of attribute/index pairs.
69 typedef SmallVector<ParamAttrsWithIndex,4> ParamAttrsVector;
72 /// @name Construction
75 /// @brief Construct an empty ParamAttrsList
78 /// This method ensures the uniqueness of ParamAttrsList instances. The
79 /// argument is a vector of attribute/index pairs as represented by the
80 /// ParamAttrsWithIndex structure. The vector is used in the construction of
81 /// the ParamAttrsList instance. If an instance with identical vector pairs
82 /// exists, it will be returned instead of creating a new instance.
83 /// @brief Get a ParamAttrsList instance.
84 ParamAttrsList *get(const ParamAttrsVector &attrVec);
90 /// The parameter attributes for the \p indexth parameter are returned.
91 /// The 0th parameter refers to the return type of the function. Note that
92 /// the \p param_index is an index into the function's parameters, not an
93 /// index into this class's list of attributes. The result of getParamIndex
94 /// is always suitable input to this function.
95 /// @returns The all the ParameterAttributes for the \p indexth parameter
96 /// as a uint16_t of enumeration values OR'd together.
97 /// @brief Get the attributes for a parameter
98 uint16_t getParamAttrs(uint16_t param_index) const;
100 /// This checks to see if the \p ith function parameter has the parameter
101 /// attribute given by \p attr set.
102 /// @returns true if the parameter attribute is set
103 /// @brief Determine if a ParameterAttributes is set
104 bool paramHasAttr(uint16_t i, ParameterAttributes attr) const {
105 return getParamAttrs(i) & attr;
108 /// The set of ParameterAttributes set in Attributes is converted to a
109 /// string of equivalent mnemonics. This is, presumably, for writing out
110 /// the mnemonics for the assembly writer.
111 /// @brief Convert parameter attribute bits to text
112 static std::string getParamAttrsText(uint16_t Attributes);
114 /// The \p Indexth parameter attribute is converted to string.
115 /// @brief Get the text for the parmeter attributes for one parameter.
116 std::string getParamAttrsTextByIndex(uint16_t Index) const {
117 return getParamAttrsText(getParamAttrs(Index));
120 /// @brief Comparison operator for ParamAttrsList
121 bool operator < (const ParamAttrsList& that) const {
122 if (this->attrs.size() < that.attrs.size())
124 if (this->attrs.size() > that.attrs.size())
126 for (unsigned i = 0; i < attrs.size(); ++i) {
127 if (attrs[i].index < that.attrs[i].index)
129 if (attrs[i].index > that.attrs[i].index)
131 if (attrs[i].attrs < that.attrs[i].attrs)
133 if (attrs[i].attrs > that.attrs[i].attrs)
139 /// Returns the parameter index of a particular parameter attribute in this
140 /// list of attributes. Note that the attr_index is an index into this
141 /// class's list of attributes, not the index of a parameter. The result
142 /// is the index of the parameter. Clients generally should not use this
143 /// method. It is used internally by LLVM.
144 /// @brief Get a parameter index
145 uint16_t getParamIndex(unsigned attr_index) const {
146 return attrs[attr_index].index;
149 /// Determines how many parameter attributes are set in this ParamAttrsList.
150 /// This says nothing about how many parameters the function has. It also
151 /// says nothing about the highest parameter index that has attributes.
152 /// Clients generally should not use this method. It is used internally by
154 /// @returns the number of parameter attributes in this ParamAttrsList.
155 /// @brief Return the number of parameter attributes this type has.
156 unsigned size() const { return attrs.size(); }
158 /// Clients generally should not use this method. It is used internally by
160 /// @returns true if this ParamAttrsList is empty.
161 /// @brief Determine emptiness of ParamAttrsList.
162 unsigned empty() const { return attrs.empty(); }
168 /// This method will add the \p attrs to the parameter with index
169 /// \p param_index. If the parameter index does not exist it will be created
170 /// and the \p attrs will be the only attributes set. Otherwise, any
171 /// existing attributes for the specified parameter remain set and the
172 /// attributes given by \p attrs are also set.
173 /// @brief Add ParameterAttributes.
174 void addAttributes(uint16_t param_index, uint16_t attrs);
176 /// This method will remove the \p attrs to the parameter with index
177 /// \p param_index. If the parameter index does not exist in the list,
178 /// an assertion will occur. If the specified attributes are the last
179 /// attributes set for the specified parameter index, the attributes for
180 /// that index are removed completely from the list (size is decremented).
181 /// Otherwise, the specified attributes are removed from the set of
182 /// attributes for the given index, retaining any others.
183 /// @brief Remove a single ParameterAttribute
184 void removeAttributes(uint16_t param_index, uint16_t attrs);
190 ParamAttrsVector attrs; ///< The list of attributes
194 } // End llvm namespace