-/// Attributes - A bitset of attributes.
-typedef unsigned Attributes;
-
-namespace Attribute {
-
-/// 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, function
-/// results or the function itself.
-/// @brief Function attributes.
-
-const Attributes None = 0; ///< No attributes have been set
-const Attributes ZExt = 1<<0; ///< Zero extended before/after call
-const Attributes SExt = 1<<1; ///< Sign extended before/after call
-const Attributes NoReturn = 1<<2; ///< Mark the function as not returning
-const Attributes InReg = 1<<3; ///< Force argument to be passed in register
-const Attributes StructRet = 1<<4; ///< Hidden pointer to structure to return
-const Attributes NoUnwind = 1<<5; ///< Function doesn't unwind stack
-const Attributes NoAlias = 1<<6; ///< Considered to not alias after call
-const Attributes ByVal = 1<<7; ///< Pass structure by value
-const Attributes Nest = 1<<8; ///< Nested function static chain
-const Attributes ReadNone = 1<<9; ///< Function does not access memory
-const Attributes ReadOnly = 1<<10; ///< Function only reads from memory
-const Attributes NoInline = 1<<11; ///< inline=never
-const Attributes AlwaysInline = 1<<12; ///< inline=always
-const Attributes OptimizeForSize = 1<<13; ///< opt_size
-const Attributes StackProtect = 1<<14; ///< Stack protection.
-const Attributes StackProtectReq = 1<<15; ///< Stack protection required.
-const Attributes Alignment = 31<<16; ///< Alignment of parameter (5 bits)
- // stored as log2 of alignment with +1 bias
- // 0 means unaligned different from align 1
-const Attributes NoCapture = 1<<21; ///< Function creates no aliases of pointer
-const Attributes NoRedZone = 1<<22; /// disable redzone
-const Attributes NoImplicitFloat = 1<<23; /// disable implicit floating point
- /// instructions.
-const Attributes Naked = 1<<24; ///< Naked function
-const Attributes InlineHint = 1<<25; ///< source said inlining was
- ///desirable
-const Attributes StackAlignment = 31<<26; ///< Alignment of stack for
- ///function (5 bits) stored as log2
- ///of alignment with +1 bias
- ///0 means unaligned (different from
- ///alignstack(1))
-
-/// @brief Attributes that only apply to function parameters.
-const Attributes ParameterOnly = ByVal | Nest | StructRet | NoCapture;
-
-/// @brief Attributes that may be applied to the function itself. These cannot
-/// be used on return values or function parameters.
-const Attributes FunctionOnly = NoReturn | NoUnwind | ReadNone | ReadOnly |
- NoInline | AlwaysInline | OptimizeForSize | StackProtect | StackProtectReq |
- NoRedZone | NoImplicitFloat | Naked | InlineHint | StackAlignment;
-
-/// @brief Parameter attributes that do not apply to vararg call arguments.
-const Attributes VarArgsIncompatible = StructRet;
-
-/// @brief Attributes that are mutually incompatible.
-const Attributes MutuallyIncompatible[4] = {
- ByVal | InReg | Nest | StructRet,
- ZExt | SExt,
- ReadNone | ReadOnly,
- NoInline | AlwaysInline
+//===----------------------------------------------------------------------===//
+/// \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;
+
+ /// \brief Return true if attributes exist
+ bool hasAttributes() const;
+
+ /// \brief Return true if the attributes are a non-null intersection.
+ bool hasAttributes(const Attribute &A) const;
+
+ /// \brief Returns the alignment field of an attribute as a byte alignment
+ /// value.
+ unsigned getAlignment() const;
+
+ /// \brief Returns the stack alignment field of an attribute as a byte
+ /// alignment value.
+ unsigned getStackAlignment() const;
+
+ bool operator==(const Attribute &A) const {
+ return pImpl == A.pImpl;
+ }
+ bool operator!=(const Attribute &A) const {
+ return pImpl != A.pImpl;
+ }
+
+ uint64_t getBitMask() const;
+
+ /// \brief Which attributes cannot be applied to a type.
+ static Attribute typeIncompatible(Type *Ty);
+
+ /// \brief This returns an integer containing an encoding of all the LLVM
+ /// attributes found in the given attribute bitset. Any change to this
+ /// encoding is a breaking change to bitcode compatibility.
+ static uint64_t encodeLLVMAttributesForBitcode(Attribute Attrs);
+
+ /// \brief This returns an attribute bitset containing the LLVM attributes
+ /// that have been decoded from the given integer. This function must stay in
+ /// sync with 'encodeLLVMAttributesForBitcode'.
+ static Attribute decodeLLVMAttributesForBitcode(LLVMContext &C,
+ uint64_t EncodedAttrs);
+
+ /// \brief The set of attributes set in Attribute is converted to a string of
+ /// equivalent mnemonics. This is, presumably, for writing out the mnemonics
+ /// for the assembly writer.
+ std::string getAsString() const;