1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_COMPILER_UTILS_LABEL_H_ 18 #define ART_COMPILER_UTILS_LABEL_H_ 19 20 #include "base/logging.h" 21 #include "base/macros.h" 22 23 namespace art { 24 25 class Assembler; 26 class AssemblerBuffer; 27 class AssemblerFixup; 28 29 namespace arm { 30 class ArmAssembler; 31 class Arm32Assembler; 32 class Thumb2Assembler; 33 } 34 namespace arm64 { 35 class Arm64Assembler; 36 } 37 namespace mips { 38 class MipsAssembler; 39 } 40 namespace mips64 { 41 class Mips64Assembler; 42 } 43 namespace x86 { 44 class X86Assembler; 45 class NearLabel; 46 } 47 namespace x86_64 { 48 class X86_64Assembler; 49 class NearLabel; 50 } 51 52 class ExternalLabel { 53 public: ExternalLabel(const char * name_in,uintptr_t address_in)54 ExternalLabel(const char* name_in, uintptr_t address_in) 55 : name_(name_in), address_(address_in) { 56 DCHECK(name_in != nullptr); 57 } 58 name()59 const char* name() const { return name_; } address()60 uintptr_t address() const { 61 return address_; 62 } 63 64 private: 65 const char* name_; 66 const uintptr_t address_; 67 }; 68 69 class Label { 70 public: Label()71 Label() : position_(0) {} 72 Label(Label && src)73 Label(Label&& src) 74 : position_(src.position_) { 75 // We must unlink/unbind the src label when moving; if not, calling the destructor on 76 // the src label would fail. 77 src.position_ = 0; 78 } 79 ~Label()80 ~Label() { 81 // Assert if label is being destroyed with unresolved branches pending. 82 CHECK(!IsLinked()); 83 } 84 85 // Returns the position for bound and linked labels. Cannot be used 86 // for unused labels. Position()87 int Position() const { 88 CHECK(!IsUnused()); 89 return IsBound() ? -position_ - sizeof(void*) : position_ - sizeof(void*); 90 } 91 LinkPosition()92 int LinkPosition() const { 93 CHECK(IsLinked()); 94 return position_ - sizeof(void*); 95 } 96 IsBound()97 bool IsBound() const { return position_ < 0; } IsUnused()98 bool IsUnused() const { return position_ == 0; } IsLinked()99 bool IsLinked() const { return position_ > 0; } 100 101 private: 102 int position_; 103 Reinitialize()104 void Reinitialize() { 105 position_ = 0; 106 } 107 BindTo(int position)108 void BindTo(int position) { 109 CHECK(!IsBound()); 110 position_ = -position - sizeof(void*); 111 CHECK(IsBound()); 112 } 113 LinkTo(int position)114 void LinkTo(int position) { 115 CHECK(!IsBound()); 116 position_ = position + sizeof(void*); 117 CHECK(IsLinked()); 118 } 119 120 friend class arm::ArmAssembler; 121 friend class arm::Arm32Assembler; 122 friend class arm::Thumb2Assembler; 123 friend class arm64::Arm64Assembler; 124 friend class mips::MipsAssembler; 125 friend class mips64::Mips64Assembler; 126 friend class x86::X86Assembler; 127 friend class x86::NearLabel; 128 friend class x86_64::X86_64Assembler; 129 friend class x86_64::NearLabel; 130 131 DISALLOW_COPY_AND_ASSIGN(Label); 132 }; 133 134 } // namespace art 135 136 #endif // ART_COMPILER_UTILS_LABEL_H_ 137