llvm-6502/include/llvm/IR/Attributes.h
Bill Wendling 73dee180c8 Make sure that the Attribute object represents one attribute only.
Several places were still treating the Attribute object as respresenting
multiple attributes. Those places now use the AttributeSet to represent
multiple attributes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174003 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-31 00:29:54 +00:00

467 lines
18 KiB
C++

//===-- 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_IR_ATTRIBUTES_H
#define LLVM_IR_ATTRIBUTES_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/FoldingSet.h"
#include <cassert>
#include <string>
namespace llvm {
class AttrBuilder;
class AttributeImpl;
class AttributeSetImpl;
class AttributeSetNode;
class Constant;
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: The `uwtable' attribute 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.
StackProtectStrong, ///< Strong Stack protection.
StructRet, ///< Hidden pointer to structure to return
UWTable, ///< Function must be in a unwind table
ZExt, ///< Zero extended before/after call
EndAttrKinds, ///< Sentinal value useful for loops
AttrKindEmptyKey, ///< Empty key value for DenseMapInfo
AttrKindTombstoneKey ///< Tombstone key value for DenseMapInfo
};
private:
AttributeImpl *pImpl;
Attribute(AttributeImpl *A) : pImpl(A) {}
public:
Attribute() : pImpl(0) {}
//===--------------------------------------------------------------------===//
// Attribute Construction
//===--------------------------------------------------------------------===//
/// \brief Return a uniquified Attribute object.
static Attribute get(LLVMContext &Context, AttrKind Kind);
static Attribute get(LLVMContext &Context, AttrBuilder &B);
/// \brief Return a uniquified Attribute object that has the specific
/// alignment set.
static Attribute getWithAlignment(LLVMContext &Context, uint64_t Align);
static Attribute getWithStackAlignment(LLVMContext &Context, uint64_t Align);
//===--------------------------------------------------------------------===//
// Attribute Accessors
//===--------------------------------------------------------------------===//
/// \brief Return true if the attribute is present.
bool hasAttribute(AttrKind Val) const;
/// \brief Return true if attributes exist
bool hasAttributes() const;
/// \brief Return the kind of this attribute.
Constant *getAttributeKind() const;
/// \brief Return the value (if present) of the non-target-specific attribute.
ArrayRef<Constant*> getAttributeValues() 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;
/// \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;
/// \brief Equality and non-equality query methods.
bool operator==(AttrKind K) const;
bool operator!=(AttrKind K) const;
bool operator==(Attribute A) const { return pImpl == A.pImpl; }
bool operator!=(Attribute A) const { return pImpl != A.pImpl; }
/// \brief Less-than operator. Useful for sorting the attributes list.
bool operator<(Attribute A) const;
void Profile(FoldingSetNodeID &ID) const {
ID.AddPointer(pImpl);
}
// FIXME: Remove this.
uint64_t Raw() const;
};
//===----------------------------------------------------------------------===//
/// \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:
friend class AttrBuilder;
friend class AttributeSetImpl;
/// \brief The attributes that we are managing. This can be null to represent
/// the empty attributes list.
AttributeSetImpl *pImpl;
/// \brief The attributes for the specified index are returned.
AttributeSetNode *getAttributes(unsigned Idx) const;
/// \brief Create an AttributeSet with the specified parameters in it.
static AttributeSet get(LLVMContext &C,
ArrayRef<std::pair<unsigned, Attribute> > Attrs);
static AttributeSet get(LLVMContext &C,
ArrayRef<std::pair<unsigned,
AttributeSetNode*> > Attrs);
static AttributeSet getImpl(LLVMContext &C,
ArrayRef<std::pair<unsigned,
AttributeSetNode*> > Attrs);
explicit AttributeSet(AttributeSetImpl *LI) : pImpl(LI) {}
public:
AttributeSet() : pImpl(0) {}
AttributeSet(const AttributeSet &P) : pImpl(P.pImpl) {}
const AttributeSet &operator=(const AttributeSet &RHS) {
pImpl = RHS.pImpl;
return *this;
}
//===--------------------------------------------------------------------===//
// AttributeSet Construction and Mutation
//===--------------------------------------------------------------------===//
/// \brief Return an AttributeSet with the specified parameters in it.
static AttributeSet get(LLVMContext &C, ArrayRef<AttributeSet> Attrs);
static AttributeSet get(LLVMContext &C, unsigned Idx,
ArrayRef<Attribute::AttrKind> Kind);
static AttributeSet get(LLVMContext &C, unsigned Idx, AttrBuilder &B);
/// \brief Add an attribute to the attribute set at the given index. Since
/// attribute sets are immutable, this returns a new set.
AttributeSet addAttribute(LLVMContext &C, unsigned Idx,
Attribute::AttrKind Attr) const;
/// \brief Add attributes to the attribute set at the given index. Since
/// attribute sets are immutable, this returns a new set.
AttributeSet addAttributes(LLVMContext &C, unsigned Idx,
AttributeSet 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 removeAttribute(LLVMContext &C, unsigned Idx,
Attribute::AttrKind Attr) const;
/// \brief Remove the specified attributes at the specified index from this
/// attribute list. Since attribute lists are immutable, this returns the new
/// list.
AttributeSet removeAttributes(LLVMContext &C, unsigned Idx,
AttributeSet Attrs) const;
//===--------------------------------------------------------------------===//
// AttributeSet Accessors
//===--------------------------------------------------------------------===//
/// \brief The attributes for the specified index are returned.
AttributeSet getParamAttributes(unsigned Idx) const;
/// \brief The attributes for the ret value are returned.
AttributeSet getRetAttributes() const;
/// \brief The function attributes are returned.
AttributeSet getFnAttributes() const;
/// \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 Return true if the specified attribute is set for at least one
/// parameter or for the return value.
bool hasAttrSomewhere(Attribute::AttrKind Attr) const;
/// \brief Return the alignment for the specified function parameter.
unsigned getParamAlignment(unsigned Idx) 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;
/// operator==/!= - Provide equality predicates.
bool operator==(const AttributeSet &RHS) const {
return pImpl == RHS.pImpl;
}
bool operator!=(const AttributeSet &RHS) const {
return pImpl != RHS.pImpl;
}
//===--------------------------------------------------------------------===//
// AttributeSet Introspection
//===--------------------------------------------------------------------===//
// FIXME: Remove this.
uint64_t Raw(unsigned Index) const;
/// \brief Return a raw pointer that uniquely identifies this attribute list.
void *getRawPointer() const {
return pImpl;
}
/// \brief Return true if there are no attributes.
bool isEmpty() const {
return getNumSlots() == 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 index for the given slot.
uint64_t getSlotIndex(unsigned Slot) const;
/// \brief Return the attributes at the given slot.
AttributeSet getSlotAttributes(unsigned Slot) const;
void dump() const;
};
//===----------------------------------------------------------------------===//
/// \class
/// \brief Provide DenseMapInfo for Attribute::AttrKinds. This is used by
/// AttrBuilder.
template<> struct DenseMapInfo<Attribute::AttrKind> {
static inline Attribute::AttrKind getEmptyKey() {
return Attribute::AttrKindEmptyKey;
}
static inline Attribute::AttrKind getTombstoneKey() {
return Attribute::AttrKindTombstoneKey;
}
static unsigned getHashValue(const Attribute::AttrKind &Val) {
return Val * 37U;
}
static bool isEqual(const Attribute::AttrKind &LHS,
const Attribute::AttrKind &RHS) {
return LHS == RHS;
}
};
//===----------------------------------------------------------------------===//
/// \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 {
DenseSet<Attribute::AttrKind> Attrs;
uint64_t Alignment;
uint64_t StackAlignment;
public:
AttrBuilder() : Alignment(0), StackAlignment(0) {}
explicit AttrBuilder(uint64_t B) : Alignment(0), StackAlignment(0) {
addRawValue(B);
}
AttrBuilder(const Attribute &A) : Alignment(0), StackAlignment(0) {
addAttributes(A);
}
AttrBuilder(AttributeSet AS, unsigned Idx);
void clear();
/// \brief Add an attribute to the builder.
AttrBuilder &addAttribute(Attribute::AttrKind Val);
/// \brief Remove an attribute from the builder.
AttrBuilder &removeAttribute(Attribute::AttrKind Val);
/// \brief Add the attributes to the builder.
AttrBuilder &addAttributes(Attribute A);
/// \brief Remove the attributes from the builder.
AttrBuilder &removeAttributes(AttributeSet A, uint64_t Index);
/// \brief Return true if the builder has the specified attribute.
bool contains(Attribute::AttrKind A) const;
/// \brief Return true if the builder has IR-level attributes.
bool hasAttributes() const;
/// \brief Return true if the builder has any attribute that's in the
/// specified attribute.
bool hasAttributes(AttributeSet A, uint64_t Index) const;
/// \brief Return true if the builder has an alignment attribute.
bool hasAlignmentAttr() const;
/// \brief Retrieve the alignment attribute, if it exists.
uint64_t getAlignment() const { return Alignment; }
/// \brief Retrieve the stack alignment attribute, if it exists.
uint64_t getStackAlignment() const { return StackAlignment; }
/// \brief This turns an int alignment (which must be a power of 2) into the
/// form used internally in Attribute.
AttrBuilder &addAlignmentAttr(unsigned Align);
/// \brief This turns an int stack alignment (which must be a power of 2) into
/// the form used internally in Attribute.
AttrBuilder &addStackAlignmentAttr(unsigned Align);
typedef DenseSet<Attribute::AttrKind>::iterator iterator;
typedef DenseSet<Attribute::AttrKind>::const_iterator const_iterator;
iterator begin() { return Attrs.begin(); }
iterator end() { return Attrs.end(); }
const_iterator begin() const { return Attrs.begin(); }
const_iterator end() const { return Attrs.end(); }
/// \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::StackProtectStrong)
.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);
}
bool operator==(const AttrBuilder &B);
bool operator!=(const AttrBuilder &B) {
return !(*this == B);
}
// FIXME: Remove these.
/// \brief Add the raw value to the internal representation.
///
/// N.B. This should be used ONLY for decoding LLVM bitcode!
AttrBuilder &addRawValue(uint64_t Val);
uint64_t Raw() const;
};
namespace AttributeFuncs {
/// \brief Which attributes cannot be applied to a type.
AttributeSet typeIncompatible(Type *Ty, uint64_t Index);
/// \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.
uint64_t encodeLLVMAttributesForBitcode(AttributeSet Attrs, unsigned Index);
/// \brief This fills an AttrBuilder object with the LLVM attributes that have
/// been decoded from the given integer. This function must stay in sync with
/// 'encodeLLVMAttributesForBitcode'.
/// N.B. This should be used only by the bitcode reader!
void decodeLLVMAttributesForBitcode(LLVMContext &C, AttrBuilder &B,
uint64_t EncodedAttrs);
} // end AttributeFuncs namespace
} // end llvm namespace
#endif