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| //===- ObjCARCInstKind.h - ARC instruction equivalence classes --*- 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
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_OBJCARCINSTKIND_H
#define LLVM_ANALYSIS_OBJCARCINSTKIND_H
#include "llvm/IR/Function.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Instructions.h"
namespace llvm {
namespace objcarc {
/// \enum ARCInstKind
///
/// Equivalence classes of instructions in the ARC Model.
///
/// Since we do not have "instructions" to represent ARC concepts in LLVM IR,
/// we instead operate on equivalence classes of instructions.
///
/// TODO: This should be split into two enums: a runtime entry point enum
/// (possibly united with the ARCRuntimeEntrypoint class) and an enum that deals
/// with effects of instructions in the ARC model (which would handle the notion
/// of a User or CallOrUser).
enum class ARCInstKind {
Retain, ///< objc_retain
RetainRV, ///< objc_retainAutoreleasedReturnValue
ClaimRV, ///< objc_unsafeClaimAutoreleasedReturnValue
RetainBlock, ///< objc_retainBlock
Release, ///< objc_release
Autorelease, ///< objc_autorelease
AutoreleaseRV, ///< objc_autoreleaseReturnValue
AutoreleasepoolPush, ///< objc_autoreleasePoolPush
AutoreleasepoolPop, ///< objc_autoreleasePoolPop
NoopCast, ///< objc_retainedObject, etc.
FusedRetainAutorelease, ///< objc_retainAutorelease
FusedRetainAutoreleaseRV, ///< objc_retainAutoreleaseReturnValue
LoadWeakRetained, ///< objc_loadWeakRetained (primitive)
StoreWeak, ///< objc_storeWeak (primitive)
InitWeak, ///< objc_initWeak (derived)
LoadWeak, ///< objc_loadWeak (derived)
MoveWeak, ///< objc_moveWeak (derived)
CopyWeak, ///< objc_copyWeak (derived)
DestroyWeak, ///< objc_destroyWeak (derived)
StoreStrong, ///< objc_storeStrong (derived)
IntrinsicUser, ///< llvm.objc.clang.arc.use
CallOrUser, ///< could call objc_release and/or "use" pointers
Call, ///< could call objc_release
User, ///< could "use" a pointer
None ///< anything that is inert from an ARC perspective.
};
raw_ostream &operator<<(raw_ostream &OS, const ARCInstKind Class);
/// Test if the given class is a kind of user.
bool IsUser(ARCInstKind Class);
/// Test if the given class is objc_retain or equivalent.
bool IsRetain(ARCInstKind Class);
/// Test if the given class is objc_autorelease or equivalent.
bool IsAutorelease(ARCInstKind Class);
/// Test if the given class represents instructions which return their
/// argument verbatim.
bool IsForwarding(ARCInstKind Class);
/// Test if the given class represents instructions which do nothing if
/// passed a null pointer.
bool IsNoopOnNull(ARCInstKind Class);
/// Test if the given class represents instructions which do nothing if
/// passed a global variable.
bool IsNoopOnGlobal(ARCInstKind Class);
/// Test if the given class represents instructions which are always safe
/// to mark with the "tail" keyword.
bool IsAlwaysTail(ARCInstKind Class);
/// Test if the given class represents instructions which are never safe
/// to mark with the "tail" keyword.
bool IsNeverTail(ARCInstKind Class);
/// Test if the given class represents instructions which are always safe
/// to mark with the nounwind attribute.
bool IsNoThrow(ARCInstKind Class);
/// Test whether the given instruction can autorelease any pointer or cause an
/// autoreleasepool pop.
bool CanInterruptRV(ARCInstKind Class);
/// Determine if F is one of the special known Functions. If it isn't,
/// return ARCInstKind::CallOrUser.
ARCInstKind GetFunctionClass(const Function *F);
/// Determine which objc runtime call instruction class V belongs to.
///
/// This is similar to GetARCInstKind except that it only detects objc
/// runtime calls. This allows it to be faster.
///
inline ARCInstKind GetBasicARCInstKind(const Value *V) {
if (const CallInst *CI = dyn_cast<CallInst>(V)) {
if (const Function *F = CI->getCalledFunction())
return GetFunctionClass(F);
// Otherwise, be conservative.
return ARCInstKind::CallOrUser;
}
// Otherwise, be conservative.
return isa<InvokeInst>(V) ? ARCInstKind::CallOrUser : ARCInstKind::User;
}
/// Map V to its ARCInstKind equivalence class.
ARCInstKind GetARCInstKind(const Value *V);
/// Returns false if conservatively we can prove that any instruction mapped to
/// this kind can not decrement ref counts. Returns true otherwise.
bool CanDecrementRefCount(ARCInstKind Kind);
} // end namespace objcarc
} // end namespace llvm
#endif
|