llvm/llvm/include/llvm/IR/Attributes.h

//===- llvm/Attributes.h - Container for Attributes -------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file
/// 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-c/Types.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitmaskEnum.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/ModRef.h"
#include "llvm/Support/PointerLikeTypeTraits.h"
#include <cassert>
#include <cstdint>
#include <optional>
#include <string>
#include <utility>

namespace llvm {

class AttrBuilder;
class AttributeMask;
class AttributeImpl;
class AttributeListImpl;
class AttributeSetNode;
class ConstantRange;
class ConstantRangeList;
class FoldingSetNodeID;
class Function;
class LLVMContext;
class Type;
class raw_ostream;
enum FPClassTest : unsigned;

enum class AllocFnKind : uint64_t { … };

//===----------------------------------------------------------------------===//
/// \class
/// 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 { … };

// Specialized opaque value conversions.
inline LLVMAttributeRef wrap(Attribute Attr) { … }

// Specialized opaque value conversions.
inline Attribute unwrap(LLVMAttributeRef Attr) { … }

//===----------------------------------------------------------------------===//
/// \class
/// This class holds the attributes for a particular argument, parameter,
/// function, or return value. It is an immutable value type that is cheap to
/// copy. Adding and removing enum attributes is intended to be fast, but adding
/// and removing string or integer attributes involves a FoldingSet lookup.
class AttributeSet { … };

//===----------------------------------------------------------------------===//
/// \class
/// Provide DenseMapInfo for AttributeSet.
template <> struct DenseMapInfo<AttributeSet, void> { … };

//===----------------------------------------------------------------------===//
/// \class
/// This class holds the attributes for a function, its return value, and
/// its parameters. You access the attributes for each of them via an index into
/// the AttributeList object. The function attributes are at index
/// `AttributeList::FunctionIndex', the return value is at index
/// `AttributeList::ReturnIndex', and the attributes for the parameters start at
/// index `AttributeList::FirstArgIndex'.
class AttributeList { … };

//===----------------------------------------------------------------------===//
/// \class
/// Provide DenseMapInfo for AttributeList.
template <> struct DenseMapInfo<AttributeList, void> { … };

//===----------------------------------------------------------------------===//
/// \class
/// 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 { … };

namespace AttributeFuncs {

enum AttributeSafetyKind : uint8_t { … };

/// Returns true if this is a type legal for the 'nofpclass' attribute. This
/// follows the same type rules as FPMathOperator.
bool isNoFPClassCompatibleType(Type *Ty);

/// Which attributes cannot be applied to a type. The argument \p ASK indicates,
/// if only attributes that are known to be safely droppable are contained in
/// the mask; only attributes that might be unsafe to drop (e.g., ABI-related
/// attributes) are in the mask; or both.
AttributeMask typeIncompatible(Type *Ty, AttributeSafetyKind ASK = ASK_ALL);

/// Get param/return attributes which imply immediate undefined behavior if an
/// invalid value is passed. For example, this includes noundef (where undef
/// implies UB), but not nonnull (where null implies poison). It also does not
/// include attributes like nocapture, which constrain the function
/// implementation rather than the passed value.
AttributeMask getUBImplyingAttributes();

/// \returns Return true if the two functions have compatible target-independent
/// attributes for inlining purposes.
bool areInlineCompatible(const Function &Caller, const Function &Callee);


/// Checks  if there are any incompatible function attributes between
/// \p A and \p B.
///
/// \param [in] A - The first function to be compared with.
/// \param [in] B - The second function to be compared with.
/// \returns true if the functions have compatible attributes.
bool areOutlineCompatible(const Function &A, const Function &B);

/// Merge caller's and callee's attributes.
void mergeAttributesForInlining(Function &Caller, const Function &Callee);

/// Merges the functions attributes from \p ToMerge into function \p Base.
///
/// \param [in,out] Base - The function being merged into.
/// \param [in] ToMerge - The function to merge attributes from.
void mergeAttributesForOutlining(Function &Base, const Function &ToMerge);

/// Update min-legal-vector-width if it is in Attribute and less than Width.
void updateMinLegalVectorWidthAttr(Function &Fn, uint64_t Width);

} // end namespace AttributeFuncs

} // end namespace llvm

#endif // LLVM_IR_ATTRIBUTES_H