#define LLVM_PARAMETER_ATTRIBUTES_H
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/FoldingSet.h"
namespace llvm {
-
-/// Function parameters can have attributes to indicate how they should be
-/// treated by optimizations and code generation. This enumeration lists the
-/// attributes that can be associated with parameters or function results.
-/// @brief Function parameter attributes.
namespace ParamAttr {
+/// Function parameters and results can have attributes to indicate how they
+/// should be treated by optimizations and code generation. This enumeration
+/// lists the attributes that can be associated with parameters or function
+/// results.
+/// @brief Function parameter attributes.
enum Attributes {
None = 0, ///< No attributes have been set
ZExt = 1 << 0, ///< zero extended before/after call
NoReturn = 1 << 2, ///< mark the function as not returning
InReg = 1 << 3, ///< force argument to be passed in register
StructRet = 1 << 4, ///< hidden pointer to structure to return
- NoUnwind = 1 << 5 ///< Function doesn't unwind stack
+ NoUnwind = 1 << 5, ///< Function doesn't unwind stack
+ NoAlias = 1 << 6 ///< Considered to not alias after call.
};
}
-typedef ParamAttr::Attributes ParameterAttributes;
-
-/// This class is used by Function and CallInst to represent the set of
-/// parameter attributes used. It represents a list of pairs of uint16_t, one
-/// for the parameter index, and one a set of ParameterAttributes bits.
-/// Parameters that have no attributes are not present in the list. The list
-/// may also be empty, but this doesn't occur in practice. The list constructs
-/// as empty and is filled by the insert method. The list can be turned into
-/// a string of mnemonics suitable for LLVM Assembly output. Various accessors
-/// are provided to obtain information about the attributes.
-/// @brief A List of ParameterAttributes.
-class ParamAttrsList {
- //void operator=(const ParamAttrsList &); // Do not implement
- //ParamAttrsList(const ParamAttrsList &); // Do not implement
+/// This is just a pair of values to associate a set of parameter attributes
+/// with a parameter index.
+/// @brief ParameterAttributes with a parameter index.
+struct ParamAttrsWithIndex {
+ uint16_t attrs; ///< The attributes that are set, |'d together
+ uint16_t index; ///< Index of the parameter for which the attributes apply
+
+ static ParamAttrsWithIndex get(uint16_t idx, uint16_t attrs) {
+ ParamAttrsWithIndex P;
+ P.index = idx;
+ P.attrs = attrs;
+ return P;
+ }
+};
- /// @name Types
- /// @{
- public:
- /// This is an internal structure used to associate the ParameterAttributes
- /// with a parameter index.
- /// @brief ParameterAttributes with a parameter index.
- struct ParamAttrsWithIndex {
- uint16_t attrs; ///< The attributes that are set, |'d together
- uint16_t index; ///< Index of the parameter for which the attributes apply
- };
+/// @brief A vector of attribute/index pairs.
+typedef SmallVector<ParamAttrsWithIndex,4> ParamAttrsVector;
- /// @brief A vector of attribute/index pairs.
- typedef SmallVector<ParamAttrsWithIndex,4> ParamAttrsVector;
+/// @brief A more friendly way to reference the attributes.
+typedef ParamAttr::Attributes ParameterAttributes;
- /// @}
+/// This class represents a list of attribute/index pairs for parameter
+/// attributes. Each entry in the list contains the index of a function
+/// parameter and the associated ParameterAttributes. If a parameter's index is
+/// not present in the list, then no attributes are set for that parameter. The
+/// list may also be empty, but this does not occur in practice. An item in
+/// the list with an index of 0 refers to the function as a whole or its result.
+/// To construct a ParamAttrsList, you must first fill a ParamAttrsVector with
+/// the attribute/index pairs you wish to set. The list of attributes can be
+/// turned into a string of mnemonics suitable for LLVM Assembly output.
+/// Various accessors are provided to obtain information about the attributes.
+/// Note that objects of this class are "uniqued". The \p get method can return
+/// the pointer of an existing and identical instance. Consequently, reference
+/// counting is necessary in order to determine when the last reference to a
+/// ParamAttrsList of a given shape is dropped. Users of this class should use
+/// the addRef and dropRef methods to add/drop references. When the reference
+/// count goes to zero, the ParamAttrsList object is deleted.
+/// This class is used by Function, CallInst and InvokeInst to represent their
+/// sets of parameter attributes.
+/// @brief A List of ParameterAttributes.
+class ParamAttrsList : public FoldingSetNode {
/// @name Construction
/// @{
- public:
- /// @brief Construct an empty ParamAttrsList
- ParamAttrsList() {}
+ private:
+ // ParamAttrsList is uniqued, these should not be publicly available
+ void operator=(const ParamAttrsList &); // Do not implement
+ ParamAttrsList(const ParamAttrsList &); // Do not implement
+ ParamAttrsList(); // Do not implement
+ ~ParamAttrsList(); // Private implementation
+
+ /// Only the \p get method can invoke this when it wants to create a
+ /// new instance.
+ /// @brief Construct an ParamAttrsList from a ParamAttrsVector
+ explicit ParamAttrsList(const ParamAttrsVector &attrVec)
+ : attrs(attrVec), refCount(0) {}
+ public:
/// This method ensures the uniqueness of ParamAttrsList instances. The
/// argument is a vector of attribute/index pairs as represented by the
/// ParamAttrsWithIndex structure. The vector is used in the construction of
/// the ParamAttrsList instance. If an instance with identical vector pairs
/// exists, it will be returned instead of creating a new instance.
/// @brief Get a ParamAttrsList instance.
- ParamAttrsList *get(const ParamAttrsVector &attrVec);
+ static ParamAttrsList *get(const ParamAttrsVector &attrVec);
/// @}
/// @name Accessors
return attrs[attr_index].index;
}
+ uint16_t getParamAttrsAtIndex(unsigned attr_index) const {
+ return attrs[attr_index].attrs;
+ }
+
/// Determines how many parameter attributes are set in this ParamAttrsList.
/// This says nothing about how many parameters the function has. It also
/// says nothing about the highest parameter index that has attributes.
/// @brief Return the number of parameter attributes this type has.
unsigned size() const { return attrs.size(); }
- /// Clients generally should not use this method. It is used internally by
- /// LLVM.
- /// @returns true if this ParamAttrsList is empty.
- /// @brief Determine emptiness of ParamAttrsList.
- unsigned empty() const { return attrs.empty(); }
+ /// Classes retaining references to ParamAttrsList objects should call this
+ /// method to increment the reference count. This ensures that the
+ /// ParamAttrsList object will not disappear until the class drops it.
+ /// @brief Add a reference to this instance.
+ void addRef() const { refCount++; }
+
+ /// Classes retaining references to ParamAttrsList objects should call this
+ /// method to decrement the reference count and possibly delete the
+ /// ParamAttrsList object. This ensures that ParamAttrsList objects are
+ /// cleaned up only when the last reference to them is dropped.
+ /// @brief Drop a reference to this instance.
+ void dropRef() const {
+ assert(refCount != 0 && "dropRef without addRef");
+ if (--refCount == 0)
+ delete this;
+ }
/// @}
- /// @name Mutators
+ /// @name Implementation Details
/// @{
public:
- /// This method will add the \p attrs to the parameter with index
- /// \p param_index. If the parameter index does not exist it will be created
- /// and the \p attrs will be the only attributes set. Otherwise, any
- /// existing attributes for the specified parameter remain set and the
- /// attributes given by \p attrs are also set.
- /// @brief Add ParameterAttributes.
- void addAttributes(uint16_t param_index, uint16_t attrs);
-
- /// This method will remove the \p attrs to the parameter with index
- /// \p param_index. If the parameter index does not exist in the list,
- /// an assertion will occur. If the specified attributes are the last
- /// attributes set for the specified parameter index, the attributes for
- /// that index are removed completely from the list (size is decremented).
- /// Otherwise, the specified attributes are removed from the set of
- /// attributes for the given index, retaining any others.
- /// @brief Remove a single ParameterAttribute
- void removeAttributes(uint16_t param_index, uint16_t attrs);
+ void Profile(FoldingSetNodeID &ID) const;
+ void dump() const;
/// @}
/// @name Data
/// @{
private:
- ParamAttrsVector attrs; ///< The list of attributes
+ ParamAttrsVector attrs; ///< The list of attributes
+ mutable unsigned refCount; ///< The number of references to this object
/// @}
};