1//===- ObjCARCUtil.h - ObjC ARC Utility Functions ---------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8/// \file
9/// This file defines ARC utility functions which are used by various parts of
10/// the compiler.
11///
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ANALYSIS_OBJCARCUTIL_H
15#define LLVM_ANALYSIS_OBJCARCUTIL_H
16
17#include "llvm/Analysis/ObjCARCInstKind.h"
18#include "llvm/IR/Function.h"
19#include "llvm/IR/InstrTypes.h"
20#include "llvm/IR/LLVMContext.h"
21
22namespace llvm {
23namespace objcarc {
24
25inline const char *getRVMarkerModuleFlagStr() {
26 return "clang.arc.retainAutoreleasedReturnValueMarker";
27}
28
29inline bool hasAttachedCallOpBundle(const CallBase *CB) {
30 // Ignore the bundle if the return type is void. Global optimization passes
31 // can turn the called function's return type to void. That should happen only
32 // if the call doesn't return and the call to @llvm.objc.clang.arc.noop.use
33 // no longer consumes the function return or is deleted. In that case, it's
34 // not necessary to emit the marker instruction or calls to the ARC runtime
35 // functions.
36 return !CB->getFunctionType()->getReturnType()->isVoidTy() &&
37 CB->getOperandBundle(ID: LLVMContext::OB_clang_arc_attachedcall)
38 .has_value();
39}
40
41/// This function returns operand bundle clang_arc_attachedcall's argument,
42/// which is the address of the ARC runtime function.
43inline std::optional<Function *> getAttachedARCFunction(const CallBase *CB) {
44 auto B = CB->getOperandBundle(ID: LLVMContext::OB_clang_arc_attachedcall);
45 if (!B)
46 return std::nullopt;
47
48 return cast<Function>(Val: B->Inputs[0]);
49}
50
51/// This function determines whether the clang_arc_attachedcall should be
52/// emitted with or without the marker.
53/// Concretely, this is the difference between:
54/// objc_retainAutoreleasedReturnValue
55/// and
56/// objc_claimAutoreleasedReturnValue
57/// retainRV (and unsafeClaimRV) requires a marker, but claimRV does not.
58inline bool attachedCallOpBundleNeedsMarker(const CallBase *CB) {
59 // FIXME: do this on ARCRuntimeEntryPoints, and do the todo above ARCInstKind
60 if (std::optional<Function *> Fn = getAttachedARCFunction(CB))
61 if ((*Fn)->getName() == "objc_claimAutoreleasedReturnValue")
62 return false;
63 return true;
64}
65
66/// Check whether the function is retainRV/unsafeClaimRV.
67inline bool isRetainOrClaimRV(ARCInstKind Kind) {
68 return Kind == ARCInstKind::RetainRV || Kind == ARCInstKind::UnsafeClaimRV;
69}
70
71/// This function returns the ARCInstKind of the function attached to operand
72/// bundle clang_arc_attachedcall. It returns std::nullopt if the call doesn't
73/// have the operand bundle or the operand is null. Otherwise it returns either
74/// RetainRV or UnsafeClaimRV.
75inline ARCInstKind getAttachedARCFunctionKind(const CallBase *CB) {
76 std::optional<Function *> Fn = getAttachedARCFunction(CB);
77 if (!Fn)
78 return ARCInstKind::None;
79 auto FnClass = GetFunctionClass(F: *Fn);
80 assert(isRetainOrClaimRV(FnClass) && "unexpected ARC runtime function");
81 return FnClass;
82}
83
84} // end namespace objcarc
85} // end namespace llvm
86
87#endif
88