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 <android-base/logging.h> 21 #include <android-base/macros.h> 22 23 namespace art { 24 25 class Assembler; 26 class AssemblerBuffer; 27 class AssemblerFixup; 28 29 namespace arm64 { 30 class Arm64Assembler; 31 } // namespace arm64 32 namespace mips { 33 class MipsAssembler; 34 class MipsLabel; 35 } // namespace mips 36 namespace mips64 { 37 class Mips64Assembler; 38 class Mips64Label; 39 } // namespace mips64 40 namespace x86 { 41 class X86Assembler; 42 class NearLabel; 43 } // namespace x86 44 namespace x86_64 { 45 class X86_64Assembler; 46 class NearLabel; 47 } // namespace x86_64 48 49 class ExternalLabel { 50 public: ExternalLabel(const char * name_in,uintptr_t address_in)51 ExternalLabel(const char* name_in, uintptr_t address_in) 52 : name_(name_in), address_(address_in) { 53 DCHECK(name_in != nullptr); 54 } 55 name()56 const char* name() const { return name_; } address()57 uintptr_t address() const { 58 return address_; 59 } 60 61 private: 62 const char* name_; 63 const uintptr_t address_; 64 }; 65 66 class Label { 67 public: Label()68 Label() : position_(0) {} 69 Label(Label && src)70 Label(Label&& src) 71 : position_(src.position_) { 72 // We must unlink/unbind the src label when moving; if not, calling the destructor on 73 // the src label would fail. 74 src.position_ = 0; 75 } 76 ~Label()77 ~Label() { 78 // Assert if label is being destroyed with unresolved branches pending. 79 CHECK(!IsLinked()); 80 } 81 82 // Returns the position for bound and linked labels. Cannot be used 83 // for unused labels. Position()84 int Position() const { 85 CHECK(!IsUnused()); 86 return IsBound() ? -position_ - sizeof(void*) : position_ - sizeof(void*); 87 } 88 LinkPosition()89 int LinkPosition() const { 90 CHECK(IsLinked()); 91 return position_ - sizeof(void*); 92 } 93 IsBound()94 bool IsBound() const { return position_ < 0; } IsUnused()95 bool IsUnused() const { return position_ == 0; } IsLinked()96 bool IsLinked() const { return position_ > 0; } 97 98 private: 99 int position_; 100 Reinitialize()101 void Reinitialize() { 102 position_ = 0; 103 } 104 BindTo(int position)105 void BindTo(int position) { 106 CHECK(!IsBound()); 107 position_ = -position - sizeof(void*); 108 CHECK(IsBound()); 109 } 110 LinkTo(int position)111 void LinkTo(int position) { 112 CHECK(!IsBound()); 113 position_ = position + sizeof(void*); 114 CHECK(IsLinked()); 115 } 116 117 friend class arm64::Arm64Assembler; 118 friend class mips::MipsAssembler; 119 friend class mips::MipsLabel; 120 friend class mips64::Mips64Assembler; 121 friend class mips64::Mips64Label; 122 friend class x86::X86Assembler; 123 friend class x86::NearLabel; 124 friend class x86_64::X86_64Assembler; 125 friend class x86_64::NearLabel; 126 127 DISALLOW_COPY_AND_ASSIGN(Label); 128 }; 129 130 } // namespace art 131 132 #endif // ART_COMPILER_UTILS_LABEL_H_ 133