Constants.h | Explore in Territory

//===-- llvm/Constants.h - Constant class subclass definitions --*- 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 declarations for the subclasses of Constant,
/// which represent the different flavors of constant values that live in LLVM.
/// Note that Constants are immutable (once created they never change) and are
/// fully shared by structural equivalence.  This means that two structurally
/// equivalent constants will always have the same address.  Constants are
/// created on demand as needed and never deleted: thus clients don't have to
/// worry about the lifetime of the objects.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_CONSTANTS_H
#define LLVM_IR_CONSTANTS_H

#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GEPNoWrapFlags.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/OperandTraits.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <optional>

namespace llvm {

template <class ConstantClass> struct ConstantAggrKeyType;

/// Base class for constants with no operands.
///
/// These constants have no operands; they represent their data directly.
/// Since they can be in use by unrelated modules (and are never based on
/// GlobalValues), it never makes sense to RAUW them.
class ConstantData : public Constant { … };

//===----------------------------------------------------------------------===//
/// This is the shared class of boolean and integer constants. This class
/// represents both boolean and integral constants.
/// Class for constant integers.
class ConstantInt final : public ConstantData { … };

//===----------------------------------------------------------------------===//
/// ConstantFP - Floating Point Values [float, double]
///
class ConstantFP final : public ConstantData { … };

//===----------------------------------------------------------------------===//
/// All zero aggregate value
///
class ConstantAggregateZero final : public ConstantData { … };

/// Base class for aggregate constants (with operands).
///
/// These constants are aggregates of other constants, which are stored as
/// operands.
///
/// Subclasses are \a ConstantStruct, \a ConstantArray, and \a
/// ConstantVector.
///
/// \note Some subclasses of \a ConstantData are semantically aggregates --
/// such as \a ConstantDataArray -- but are not subclasses of this because they
/// use operands.
class ConstantAggregate : public Constant { … };

template <>
struct OperandTraits<ConstantAggregate>
    : public VariadicOperandTraits<ConstantAggregate> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

//===----------------------------------------------------------------------===//
/// ConstantArray - Constant Array Declarations
///
class ConstantArray final : public ConstantAggregate { … };

//===----------------------------------------------------------------------===//
// Constant Struct Declarations
//
class ConstantStruct final : public ConstantAggregate { … };

//===----------------------------------------------------------------------===//
/// Constant Vector Declarations
///
class ConstantVector final : public ConstantAggregate { … };

//===----------------------------------------------------------------------===//
/// A constant pointer value that points to null
///
class ConstantPointerNull final : public ConstantData { … };

//===----------------------------------------------------------------------===//
/// ConstantDataSequential - A vector or array constant whose element type is a
/// simple 1/2/4/8-byte integer or half/bfloat/float/double, and whose elements
/// are just simple data values (i.e. ConstantInt/ConstantFP).  This Constant
/// node has no operands because it stores all of the elements of the constant
/// as densely packed data, instead of as Value*'s.
///
/// This is the common base class of ConstantDataArray and ConstantDataVector.
///
class ConstantDataSequential : public ConstantData { … };

//===----------------------------------------------------------------------===//
/// An array constant whose element type is a simple 1/2/4/8-byte integer or
/// float/double, and whose elements are just simple data values
/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
/// stores all of the elements of the constant as densely packed data, instead
/// of as Value*'s.
class ConstantDataArray final : public ConstantDataSequential { … };

//===----------------------------------------------------------------------===//
/// A vector constant whose element type is a simple 1/2/4/8-byte integer or
/// float/double, and whose elements are just simple data values
/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
/// stores all of the elements of the constant as densely packed data, instead
/// of as Value*'s.
class ConstantDataVector final : public ConstantDataSequential { … };

//===----------------------------------------------------------------------===//
/// A constant token which is empty
///
class ConstantTokenNone final : public ConstantData { … };

/// A constant target extension type default initializer
class ConstantTargetNone final : public ConstantData { … };

/// The address of a basic block.
///
class BlockAddress final : public Constant { … };

template <>
struct OperandTraits<BlockAddress>
    : public FixedNumOperandTraits<BlockAddress, 2> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

/// Wrapper for a function that represents a value that
/// functionally represents the original function. This can be a function,
/// global alias to a function, or an ifunc.
class DSOLocalEquivalent final : public Constant { … };

template <>
struct OperandTraits<DSOLocalEquivalent>
    : public FixedNumOperandTraits<DSOLocalEquivalent, 1> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

/// Wrapper for a value that won't be replaced with a CFI jump table
/// pointer in LowerTypeTestsModule.
class NoCFIValue final : public Constant { … };

template <>
struct OperandTraits<NoCFIValue> : public FixedNumOperandTraits<NoCFIValue, 1> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

/// A signed pointer, in the ptrauth sense.
class ConstantPtrAuth final : public Constant { … };

template <>
struct OperandTraits<ConstantPtrAuth>
    : public FixedNumOperandTraits<ConstantPtrAuth, 4> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

//===----------------------------------------------------------------------===//
/// A constant value that is initialized with an expression using
/// other constant values.
///
/// This class uses the standard Instruction opcodes to define the various
/// constant expressions.  The Opcode field for the ConstantExpr class is
/// maintained in the Value::SubclassData field.
class ConstantExpr : public Constant { … };

template <>
struct OperandTraits<ConstantExpr>
    : public VariadicOperandTraits<ConstantExpr, 1> { … };

DEFINE_TRANSPARENT_OPERAND_ACCESSORS(…)

//===----------------------------------------------------------------------===//
/// 'undef' values are things that do not have specified contents.
/// These are used for a variety of purposes, including global variable
/// initializers and operands to instructions.  'undef' values can occur with
/// any first-class type.
///
/// Undef values aren't exactly constants; if they have multiple uses, they
/// can appear to have different bit patterns at each use. See
/// LangRef.html#undefvalues for details.
///
class UndefValue : public ConstantData { … };

//===----------------------------------------------------------------------===//
/// In order to facilitate speculative execution, many instructions do not
/// invoke immediate undefined behavior when provided with illegal operands,
/// and return a poison value instead.
///
/// see LangRef.html#poisonvalues for details.
///
class PoisonValue final : public UndefValue { … };

} // end namespace llvm

#endif // LLVM_IR_CONSTANTS_H
llvm/llvm/include/llvm/IR/Constants.h
