llvm-6502/include/llvm/IR/Argument.h
Hal Finkel 11af4b49b2 Add a dereferenceable attribute
This attribute indicates that the parameter or return pointer is
dereferenceable. Practically speaking, loads from such a pointer within the
associated byte range are safe to speculatively execute. Such pointer
parameters are common in source languages (C++ references, for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213385 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-18 15:51:28 +00:00

124 lines
4.2 KiB
C++

//===-- llvm/Argument.h - Definition of the Argument class ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the Argument class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_ARGUMENT_H
#define LLVM_IR_ARGUMENT_H
#include "llvm/ADT/Twine.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Value.h"
namespace llvm {
template<typename ValueSubClass, typename ItemParentClass>
class SymbolTableListTraits;
/// \brief LLVM Argument representation
///
/// This class represents an incoming formal argument to a Function. A formal
/// argument, since it is ``formal'', does not contain an actual value but
/// instead represents the type, argument number, and attributes of an argument
/// for a specific function. When used in the body of said function, the
/// argument of course represents the value of the actual argument that the
/// function was called with.
class Argument : public Value, public ilist_node<Argument> {
virtual void anchor();
Function *Parent;
friend class SymbolTableListTraits<Argument, Function>;
void setParent(Function *parent);
public:
/// \brief Constructor.
///
/// If \p F is specified, the argument is inserted at the end of the argument
/// list for \p F.
explicit Argument(Type *Ty, const Twine &Name = "", Function *F = nullptr);
inline const Function *getParent() const { return Parent; }
inline Function *getParent() { return Parent; }
/// \brief Return the index of this formal argument in its containing
/// function.
///
/// For example in "void foo(int a, float b)" a is 0 and b is 1.
unsigned getArgNo() const;
/// \brief Return true if this argument has the nonnull attribute on it in
/// its containing function. Also returns true if at least one byte is known
/// to be dereferenceable and the pointer is in addrspace(0).
bool hasNonNullAttr() const;
/// \brief If this argument has the dereferenceable attribute on it in its
/// containing function, return the number of bytes known to be
/// dereferenceable. Otherwise, zero is returned.
uint64_t getDereferenceableBytes() const;
/// \brief Return true if this argument has the byval attribute on it in its
/// containing function.
bool hasByValAttr() const;
/// \brief Return true if this argument has the byval attribute or inalloca
/// attribute on it in its containing function. These attributes both
/// represent arguments being passed by value.
bool hasByValOrInAllocaAttr() const;
/// \brief If this is a byval or inalloca argument, return its alignment.
unsigned getParamAlignment() const;
/// \brief Return true if this argument has the nest attribute on it in its
/// containing function.
bool hasNestAttr() const;
/// \brief Return true if this argument has the noalias attribute on it in its
/// containing function.
bool hasNoAliasAttr() const;
/// \brief Return true if this argument has the nocapture attribute on it in
/// its containing function.
bool hasNoCaptureAttr() const;
/// \brief Return true if this argument has the sret attribute on it in its
/// containing function.
bool hasStructRetAttr() const;
/// \brief Return true if this argument has the returned attribute on it in
/// its containing function.
bool hasReturnedAttr() const;
/// \brief Return true if this argument has the readonly or readnone attribute
/// on it in its containing function.
bool onlyReadsMemory() const;
/// \brief Return true if this argument has the inalloca attribute on it in
/// its containing function.
bool hasInAllocaAttr() const;
/// \brief Add a Attribute to an argument.
void addAttr(AttributeSet AS);
/// \brief Remove a Attribute from an argument.
void removeAttr(AttributeSet AS);
/// \brief Method for support type inquiry through isa, cast, and
/// dyn_cast.
static inline bool classof(const Value *V) {
return V->getValueID() == ArgumentVal;
}
};
} // End llvm namespace
#endif