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