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/ADT/StringRef.h"
  26 #include "llvm/IR/Attributes.h"
  27 #include "llvm/IR/DerivedTypes.h"
  28 #include "llvm/IR/Intrinsics.h"
  29 #include "llvm/IR/Module.h"
  30 #include "llvm/IR/Type.h"
  31 #include "llvm/Support/ErrorHandling.h"
  32 #include <cassert>
  33
  34 namespace llvm {
  35
  36 class Function;
  37 class LLVMContext;
  38
  39 namespace objcarc {
  40
  41 enum class ARCRuntimeEntryPointKind {
  42   AutoreleaseRV,
  43   Release,
  44   Retain,
  45   RetainBlock,
  46   Autorelease,
  47   StoreStrong,
  48   RetainRV,
  49   RetainAutorelease,
  50   RetainAutoreleaseRV,
  51 };
  52
  53 /// Declarations for ObjC runtime functions and constants. These are initialized
  54 /// lazily to avoid cluttering up the Module with unused declarations.
  55 class ARCRuntimeEntryPoints {
  56 public:
  57   ARCRuntimeEntryPoints() = default;
  58
  59   void init(Module *M) {
  60     TheModule = M;
  61     AutoreleaseRV = nullptr;
  62     Release = nullptr;
  63     Retain = nullptr;
  64     RetainBlock = nullptr;
  65     Autorelease = nullptr;
  66     StoreStrong = nullptr;
  67     RetainRV = nullptr;
  68     RetainAutorelease = nullptr;
  69     RetainAutoreleaseRV = nullptr;
  70   }
  71
  72   Function *get(ARCRuntimeEntryPointKind kind) {
  73     assert(TheModule != nullptr && "Not initialized.");
  74
  75     switch (kind) {
  76     case ARCRuntimeEntryPointKind::AutoreleaseRV:
  77       return getIntrinsicEntryPoint(AutoreleaseRV,
  78                                     Intrinsic::objc_autoreleaseReturnValue);
  79     case ARCRuntimeEntryPointKind::Release:
  80       return getIntrinsicEntryPoint(Release, Intrinsic::objc_release);
  81     case ARCRuntimeEntryPointKind::Retain:
  82       return getIntrinsicEntryPoint(Retain, Intrinsic::objc_retain);
  83     case ARCRuntimeEntryPointKind::RetainBlock:
  84       return getIntrinsicEntryPoint(RetainBlock, Intrinsic::objc_retainBlock);
  85     case ARCRuntimeEntryPointKind::Autorelease:
  86       return getIntrinsicEntryPoint(Autorelease, Intrinsic::objc_autorelease);
  87     case ARCRuntimeEntryPointKind::StoreStrong:
  88       return getIntrinsicEntryPoint(StoreStrong, Intrinsic::objc_storeStrong);
  89     case ARCRuntimeEntryPointKind::RetainRV:
  90       return getIntrinsicEntryPoint(RetainRV,
  91                                 Intrinsic::objc_retainAutoreleasedReturnValue);
  92     case ARCRuntimeEntryPointKind::RetainAutorelease:
  93       return getIntrinsicEntryPoint(RetainAutorelease,
  94                                     Intrinsic::objc_retainAutorelease);
  95     case ARCRuntimeEntryPointKind::RetainAutoreleaseRV:
  96       return getIntrinsicEntryPoint(RetainAutoreleaseRV,
  97                                 Intrinsic::objc_retainAutoreleaseReturnValue);
  98     }
  99
 100     llvm_unreachable("Switch should be a covered switch.");
 101   }
 102
 103 private:
 104   /// Cached reference to the module which we will insert declarations into.
 105   Module *TheModule = nullptr;
 106
 107   /// Declaration for ObjC runtime function objc_autoreleaseReturnValue.
 108   Function *AutoreleaseRV = nullptr;
 109
 110   /// Declaration for ObjC runtime function objc_release.
 111   Function *Release = nullptr;
 112
 113   /// Declaration for ObjC runtime function objc_retain.
 114   Function *Retain = nullptr;
 115
 116   /// Declaration for ObjC runtime function objc_retainBlock.
 117   Function *RetainBlock = nullptr;
 118
 119   /// Declaration for ObjC runtime function objc_autorelease.
 120   Function *Autorelease = nullptr;
 121
 122   /// Declaration for objc_storeStrong().
 123   Function *StoreStrong = nullptr;
 124
 125   /// Declaration for objc_retainAutoreleasedReturnValue().
 126   Function *RetainRV = nullptr;
 127
 128   /// Declaration for objc_retainAutorelease().
 129   Function *RetainAutorelease = nullptr;
 130
 131   /// Declaration for objc_retainAutoreleaseReturnValue().
 132   Function *RetainAutoreleaseRV = nullptr;
 133
 134   Function *getIntrinsicEntryPoint(Function *&Decl, Intrinsic::ID IntID) {
 135     if (Decl)
 136       return Decl;
 137
 138     return Decl = Intrinsic::getDeclaration(TheModule, IntID);
 139   }
 140 };
 141
 142 } // end namespace objcarc
 143
 144 } // end namespace llvm
 145
 146 #endif // LLVM_LIB_TRANSFORMS_OBJCARC_ARCRUNTIMEENTRYPOINTS_H