llvm/lib/Transforms/ObjCARC/ARCRuntimeEntryPoints.h

   1 //===- ARCRuntimeEntryPoints.h - ObjC ARC Optimization ----------*- 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 //
   9 /// \file
  10 /// This file contains a class ARCRuntimeEntryPoints for use in
  11 /// creating/managing references to entry points to the arc objective c runtime.
  12 ///
  13 /// WARNING: This file knows about certain library functions. It recognizes them
  14 /// by name, and hardwires knowledge of their semantics.
  15 ///
  16 /// WARNING: This file knows about how certain Objective-C library functions are
  17 /// used. Naive LLVM IR transformations which would otherwise be
  18 /// behavior-preserving may break these assumptions.
  19 //
  20 //===----------------------------------------------------------------------===//
  21
  22 #ifndef LLVM_LIB_TRANSFORMS_OBJCARC_ARCRUNTIMEENTRYPOINTS_H
  23 #define LLVM_LIB_TRANSFORMS_OBJCARC_ARCRUNTIMEENTRYPOINTS_H
  24
  25 #include "llvm/IR/Attributes.h"
  26 #include "llvm/IR/Intrinsics.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include <cassert>
  29
  30 namespace llvm {
  31
  32 class Function;
  33 class Module;
  34
  35 namespace objcarc {
  36
  37 enum class ARCRuntimeEntryPointKind {
  38   AutoreleaseRV,
  39   Release,
  40   Retain,
  41   RetainBlock,
  42   Autorelease,
  43   StoreStrong,
  44   RetainRV,
  45   ClaimRV,
  46   RetainAutorelease,
  47   RetainAutoreleaseRV,
  48 };
  49
  50 /// Declarations for ObjC runtime functions and constants. These are initialized
  51 /// lazily to avoid cluttering up the Module with unused declarations.
  52 class ARCRuntimeEntryPoints {
  53 public:
  54   ARCRuntimeEntryPoints() = default;
  55
  56   void init(Module *M) {
  57     TheModule = M;
  58     AutoreleaseRV = nullptr;
  59     Release = nullptr;
  60     Retain = nullptr;
  61     RetainBlock = nullptr;
  62     Autorelease = nullptr;
  63     StoreStrong = nullptr;
  64     RetainRV = nullptr;
  65     ClaimRV = nullptr;
  66     RetainAutorelease = nullptr;
  67     RetainAutoreleaseRV = nullptr;
  68   }
  69
  70   Function *get(ARCRuntimeEntryPointKind kind) {
  71     assert(TheModule != nullptr && "Not initialized.");
  72
  73     switch (kind) {
  74     case ARCRuntimeEntryPointKind::AutoreleaseRV:
  75       return getIntrinsicEntryPoint(AutoreleaseRV,
  76                                     Intrinsic::objc_autoreleaseReturnValue);
  77     case ARCRuntimeEntryPointKind::Release:
  78       return getIntrinsicEntryPoint(Release, Intrinsic::objc_release);
  79     case ARCRuntimeEntryPointKind::Retain:
  80       return getIntrinsicEntryPoint(Retain, Intrinsic::objc_retain);
  81     case ARCRuntimeEntryPointKind::RetainBlock:
  82       return getIntrinsicEntryPoint(RetainBlock, Intrinsic::objc_retainBlock);
  83     case ARCRuntimeEntryPointKind::Autorelease:
  84       return getIntrinsicEntryPoint(Autorelease, Intrinsic::objc_autorelease);
  85     case ARCRuntimeEntryPointKind::StoreStrong:
  86       return getIntrinsicEntryPoint(StoreStrong, Intrinsic::objc_storeStrong);
  87     case ARCRuntimeEntryPointKind::RetainRV:
  88       return getIntrinsicEntryPoint(RetainRV,
  89                                 Intrinsic::objc_retainAutoreleasedReturnValue);
  90     case ARCRuntimeEntryPointKind::ClaimRV:
  91       return getIntrinsicEntryPoint(
  92           ClaimRV, Intrinsic::objc_unsafeClaimAutoreleasedReturnValue);
  93     case ARCRuntimeEntryPointKind::RetainAutorelease:
  94       return getIntrinsicEntryPoint(RetainAutorelease,
  95                                     Intrinsic::objc_retainAutorelease);
  96     case ARCRuntimeEntryPointKind::RetainAutoreleaseRV:
  97       return getIntrinsicEntryPoint(RetainAutoreleaseRV,
  98                                 Intrinsic::objc_retainAutoreleaseReturnValue);
  99     }
 100
 101     llvm_unreachable("Switch should be a covered switch.");
 102   }
 103
 104 private:
 105   /// Cached reference to the module which we will insert declarations into.
 106   Module *TheModule = nullptr;
 107
 108   /// Declaration for ObjC runtime function objc_autoreleaseReturnValue.
 109   Function *AutoreleaseRV = nullptr;
 110
 111   /// Declaration for ObjC runtime function objc_release.
 112   Function *Release = nullptr;
 113
 114   /// Declaration for ObjC runtime function objc_retain.
 115   Function *Retain = nullptr;
 116
 117   /// Declaration for ObjC runtime function objc_retainBlock.
 118   Function *RetainBlock = nullptr;
 119
 120   /// Declaration for ObjC runtime function objc_autorelease.
 121   Function *Autorelease = nullptr;
 122
 123   /// Declaration for objc_storeStrong().
 124   Function *StoreStrong = nullptr;
 125
 126   /// Declaration for objc_retainAutoreleasedReturnValue().
 127   Function *RetainRV = nullptr;
 128
 129   /// Declaration for objc_unsafeClaimAutoreleasedReturnValue().
 130   Function *ClaimRV = nullptr;
 131
 132   /// Declaration for objc_retainAutorelease().
 133   Function *RetainAutorelease = nullptr;
 134
 135   /// Declaration for objc_retainAutoreleaseReturnValue().
 136   Function *RetainAutoreleaseRV = nullptr;
 137
 138   Function *getIntrinsicEntryPoint(Function *&Decl, Intrinsic::ID IntID) {
 139     if (Decl)
 140       return Decl;
 141
 142     return Decl = Intrinsic::getDeclaration(TheModule, IntID);
 143   }
 144 };
 145
 146 } // end namespace objcarc
 147
 148 } // end namespace llvm
 149
 150 #endif // LLVM_LIB_TRANSFORMS_OBJCARC_ARCRUNTIMEENTRYPOINTS_H