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