--- /dev/null
+//===-- llvm/Attributes.h - Container for Attributes ------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief This file contains the simple types necessary to represent the
+/// attributes associated with functions and their calls.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ATTRIBUTES_H
+#define LLVM_ATTRIBUTES_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/MathExtras.h"
+#include <cassert>
+#include <string>
+
+namespace llvm {
+
+class AttrBuilder;
+class AttributeImpl;
+class LLVMContext;
+class Type;
+
+//===----------------------------------------------------------------------===//
+/// \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==(AttrKind K) const;
+ bool operator!=(AttrKind K) const;
+
+ // FIXME: Remove these 'operator' methods.
+ 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 Attribute is converted to a string of equivalent mnemonic. This
+ /// is, presumably, for writing out the mnemonics for the assembly writer.
+ std::string getAsString() const;
+};
+
+//===----------------------------------------------------------------------===//
+/// \class
+/// \brief This class is used in conjunction with the Attribute::get method to
+/// create an Attribute object. The object itself is uniquified. The Builder's
+/// value, however, is not. So this can be used as a quick way to test for
+/// equality, presence of attributes, etc.
+class AttrBuilder {
+ uint64_t Bits;
+public:
+ AttrBuilder() : Bits(0) {}
+ explicit AttrBuilder(uint64_t B) : Bits(B) {}
+ AttrBuilder(const Attribute &A) : Bits(A.getBitMask()) {}
+
+ void clear() { Bits = 0; }
+
+ /// addAttribute - Add an attribute to the builder.
+ AttrBuilder &addAttribute(Attribute::AttrKind Val);
+
+ /// removeAttribute - Remove an attribute from the builder.
+ AttrBuilder &removeAttribute(Attribute::AttrKind Val);
+
+ /// addAttribute - Add the attributes from A to the builder.
+ AttrBuilder &addAttributes(const Attribute &A);
+
+ /// removeAttribute - Remove the attributes from A from the builder.
+ AttrBuilder &removeAttributes(const Attribute &A);
+
+ /// \brief Return true if the builder has the specified attribute.
+ bool contains(Attribute::AttrKind A) const;
+
+ /// hasAttributes - Return true if the builder has IR-level attributes.
+ bool hasAttributes() const;
+
+ /// hasAttributes - Return true if the builder has any attribute that's in the
+ /// specified attribute.
+ bool hasAttributes(const Attribute &A) const;
+
+ /// hasAlignmentAttr - Return true if the builder has an alignment attribute.
+ bool hasAlignmentAttr() const;
+
+ /// getAlignment - Retrieve the alignment attribute, if it exists.
+ uint64_t getAlignment() const;
+
+ /// getStackAlignment - Retrieve the stack alignment attribute, if it exists.
+ uint64_t getStackAlignment() const;
+
+ /// addAlignmentAttr - This turns an int alignment (which must be a power of
+ /// 2) into the form used internally in Attribute.
+ AttrBuilder &addAlignmentAttr(unsigned Align);
+
+ /// addStackAlignmentAttr - This turns an int stack alignment (which must be a
+ /// power of 2) into the form used internally in Attribute.
+ AttrBuilder &addStackAlignmentAttr(unsigned Align);
+
+ /// addRawValue - Add the raw value to the internal representation.
+ /// N.B. This should be used ONLY for decoding LLVM bitcode!
+ AttrBuilder &addRawValue(uint64_t Val);
+
+ /// @brief Remove attributes that are used on functions only.
+ void removeFunctionOnlyAttrs() {
+ removeAttribute(Attribute::NoReturn)
+ .removeAttribute(Attribute::NoUnwind)
+ .removeAttribute(Attribute::ReadNone)
+ .removeAttribute(Attribute::ReadOnly)
+ .removeAttribute(Attribute::NoInline)
+ .removeAttribute(Attribute::AlwaysInline)
+ .removeAttribute(Attribute::OptimizeForSize)
+ .removeAttribute(Attribute::StackProtect)
+ .removeAttribute(Attribute::StackProtectReq)
+ .removeAttribute(Attribute::NoRedZone)
+ .removeAttribute(Attribute::NoImplicitFloat)
+ .removeAttribute(Attribute::Naked)
+ .removeAttribute(Attribute::InlineHint)
+ .removeAttribute(Attribute::StackAlignment)
+ .removeAttribute(Attribute::UWTable)
+ .removeAttribute(Attribute::NonLazyBind)
+ .removeAttribute(Attribute::ReturnsTwice)
+ .removeAttribute(Attribute::AddressSafety)
+ .removeAttribute(Attribute::MinSize)
+ .removeAttribute(Attribute::NoDuplicate);
+ }
+
+ uint64_t getBitMask() const { return Bits; }
+
+ bool operator==(const AttrBuilder &B) {
+ return Bits == B.Bits;
+ }
+ bool operator!=(const AttrBuilder &B) {
+ return Bits != B.Bits;
+ }
+};
+
+//===----------------------------------------------------------------------===//
+/// \class
+/// \brief This is just a pair of values to associate a set of attributes with
+/// an index.
+struct AttributeWithIndex {
+ Attribute Attrs; ///< The attributes that are set, or'd together.
+ unsigned Index; ///< Index of the parameter for which the attributes apply.
+ ///< Index 0 is used for return value attributes.
+ ///< Index ~0U is used for function attributes.
+
+ static AttributeWithIndex get(LLVMContext &C, unsigned Idx,
+ ArrayRef<Attribute::AttrKind> Attrs) {
+ return get(Idx, Attribute::get(C, Attrs));
+ }
+ static AttributeWithIndex get(unsigned Idx, Attribute Attrs) {
+ AttributeWithIndex P;
+ P.Index = Idx;
+ P.Attrs = Attrs;
+ return P;
+ }
+};
+
+//===----------------------------------------------------------------------===//
+// AttributeSet Smart Pointer
+//===----------------------------------------------------------------------===//
+
+class AttributeSetImpl;
+
+//===----------------------------------------------------------------------===//
+/// \class
+/// \brief This class manages the ref count for the opaque AttributeSetImpl
+/// object and provides accessors for it.
+class AttributeSet {
+public:
+ enum AttrIndex {
+ ReturnIndex = 0U,
+ FunctionIndex = ~0U
+ };
+private:
+ /// \brief The attributes that we are managing. This can be null to represent
+ /// the empty attributes list.
+ AttributeSetImpl *AttrList;
+
+ /// \brief The attributes for the specified index are returned. Attributes
+ /// for the result are denoted with Idx = 0.
+ Attribute getAttributes(unsigned Idx) const;
+
+ explicit AttributeSet(AttributeSetImpl *LI) : AttrList(LI) {}
+public:
+ AttributeSet() : AttrList(0) {}
+ AttributeSet(const AttributeSet &P) : AttrList(P.AttrList) {}
+ const AttributeSet &operator=(const AttributeSet &RHS);
+
+ //===--------------------------------------------------------------------===//
+ // Attribute List Construction and Mutation
+ //===--------------------------------------------------------------------===//
+
+ /// \brief Return an AttributeSet with the specified parameters in it.
+ static AttributeSet get(LLVMContext &C, ArrayRef<AttributeWithIndex> Attrs);
+
+ /// \brief Add the specified attribute at the specified index to this
+ /// attribute list. Since attribute lists are immutable, this returns the new
+ /// list.
+ AttributeSet addAttr(LLVMContext &C, unsigned Idx, Attribute Attrs) const;
+
+ /// \brief Remove the specified attribute at the specified index from this
+ /// attribute list. Since attribute lists are immutable, this returns the new
+ /// list.
+ AttributeSet removeAttr(LLVMContext &C, unsigned Idx, Attribute Attrs) const;
+
+ //===--------------------------------------------------------------------===//
+ // Attribute Set Accessors
+ //===--------------------------------------------------------------------===//
+
+ /// \brief The attributes for the specified index are returned.
+ Attribute getParamAttributes(unsigned Idx) const {
+ return getAttributes(Idx);
+ }
+
+ /// \brief The attributes for the ret value are returned.
+ Attribute getRetAttributes() const {
+ return getAttributes(ReturnIndex);
+ }
+
+ /// \brief The function attributes are returned.
+ Attribute getFnAttributes() const {
+ return getAttributes(FunctionIndex);
+ }
+
+ /// \brief Return the alignment for the specified function parameter.
+ unsigned getParamAlignment(unsigned Idx) const {
+ return getAttributes(Idx).getAlignment();
+ }
+
+ /// \brief Return true if the attribute exists at the given index.
+ bool hasAttribute(unsigned Index, Attribute::AttrKind Kind) const;
+
+ /// \brief Return true if attribute exists at the given index.
+ bool hasAttributes(unsigned Index) const;
+
+ /// \brief Get the stack alignment.
+ unsigned getStackAlignment(unsigned Index) const;
+
+ /// \brief Return the attributes at the index as a string.
+ std::string getAsString(unsigned Index) const;
+
+ uint64_t getBitMask(unsigned Index) const;
+
+ /// \brief Return true if the specified attribute is set for at least one
+ /// parameter or for the return value.
+ bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
+
+ /// operator==/!= - Provide equality predicates.
+ bool operator==(const AttributeSet &RHS) const {
+ return AttrList == RHS.AttrList;
+ }
+ bool operator!=(const AttributeSet &RHS) const {
+ return AttrList != RHS.AttrList;
+ }
+
+ //===--------------------------------------------------------------------===//
+ // Attribute Set Introspection
+ //===--------------------------------------------------------------------===//
+
+ /// \brief Return a raw pointer that uniquely identifies this attribute list.
+ void *getRawPointer() const {
+ return AttrList;
+ }
+
+ // Attributes are stored as a dense set of slots, where there is one slot for
+ // each argument that has an attribute. This allows walking over the dense
+ // set instead of walking the sparse list of attributes.
+
+ /// \brief Return true if there are no attributes.
+ bool isEmpty() const {
+ return AttrList == 0;
+ }
+
+ /// \brief Return the number of slots used in this attribute list. This is
+ /// the number of arguments that have an attribute set on them (including the
+ /// function itself).
+ unsigned getNumSlots() const;
+
+ /// \brief Return the AttributeWithIndex at the specified slot. This holds a
+ /// index number plus a set of attributes.
+ const AttributeWithIndex &getSlot(unsigned Slot) const;
+
+ void dump() const;
+};
+
+} // end llvm namespace
+
+#endif
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