+//===----------------------------------------------------------------------===//
+/// \class
+/// \brief Functions, function parameters, and return types can have attributes
+/// to indicate how they should be treated by optimizations and code
+/// generation. This class represents one of those attributes. It's light-weight
+/// and should be passed around by-value.
+class Attribute {
+public:
+ /// This enumeration lists the attributes that can be associated with
+ /// parameters, function results or the function itself.
+ ///
+ /// Note: uwtable is about the ABI or the user mandating an entry in the
+ /// unwind table. The nounwind attribute is about an exception passing by the
+ /// function.
+ ///
+ /// In a theoretical system that uses tables for profiling and sjlj for
+ /// exceptions, they would be fully independent. In a normal system that uses
+ /// tables for both, the semantics are:
+ ///
+ /// nil = Needs an entry because an exception might pass by.
+ /// nounwind = No need for an entry
+ /// uwtable = Needs an entry because the ABI says so and because
+ /// an exception might pass by.
+ /// uwtable + nounwind = Needs an entry because the ABI says so.
+
+ enum AttrKind {
+ // IR-Level Attributes
+ None, ///< No attributes have been set
+ AddressSafety, ///< Address safety checking is on.
+ Alignment, ///< Alignment of parameter (5 bits)
+ ///< stored as log2 of alignment with +1 bias
+ ///< 0 means unaligned (different from align(1))
+ AlwaysInline, ///< inline=always
+ ByVal, ///< Pass structure by value
+ InlineHint, ///< Source said inlining was desirable
+ InReg, ///< Force argument to be passed in register
+ MinSize, ///< Function must be optimized for size first
+ Naked, ///< Naked function
+ Nest, ///< Nested function static chain
+ NoAlias, ///< Considered to not alias after call
+ NoCapture, ///< Function creates no aliases of pointer
+ NoDuplicate, ///< Call cannot be duplicated
+ NoImplicitFloat, ///< Disable implicit floating point insts
+ NoInline, ///< inline=never
+ NonLazyBind, ///< Function is called early and/or
+ ///< often, so lazy binding isn't worthwhile
+ NoRedZone, ///< Disable redzone
+ NoReturn, ///< Mark the function as not returning
+ NoUnwind, ///< Function doesn't unwind stack
+ OptimizeForSize, ///< opt_size
+ ReadNone, ///< Function does not access memory
+ ReadOnly, ///< Function only reads from memory
+ ReturnsTwice, ///< Function can return twice
+ SExt, ///< Sign extended before/after call
+ StackAlignment, ///< Alignment of stack for function (3 bits)
+ ///< stored as log2 of alignment with +1 bias 0
+ ///< means unaligned (different from
+ ///< alignstack=(1))
+ StackProtect, ///< Stack protection.
+ StackProtectReq, ///< Stack protection required.
+ StructRet, ///< Hidden pointer to structure to return
+ UWTable, ///< Function must be in a unwind table
+ ZExt ///< Zero extended before/after call
+ };
+private:
+ AttributeImpl *pImpl;
+ Attribute(AttributeImpl *A) : pImpl(A) {}
+public:
+ Attribute() : pImpl(0) {}
+
+ /// \brief Return a uniquified Attribute object. This takes the uniquified
+ /// value from the Builder and wraps it in the Attribute class.
+ static Attribute get(LLVMContext &Context, ArrayRef<AttrKind> Vals);
+ static Attribute get(LLVMContext &Context, AttrBuilder &B);
+
+ /// \brief Return true if the attribute is present.
+ bool hasAttribute(AttrKind Val) const;