1 /* 2 * Copyright (C) 2008 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 /* 18 * Dalvik instruction utility functions. 19 */ 20 #ifndef LIBDEX_INSTRUTILS_H_ 21 #define LIBDEX_INSTRUTILS_H_ 22 23 #include "DexFile.h" 24 #include "DexOpcodes.h" 25 26 /* 27 * Possible instruction formats associated with Dalvik opcodes. 28 * 29 * See the file opcode-gen/README.txt for information about updating 30 * opcodes and instruction formats. 31 */ 32 enum InstructionFormat { 33 kFmt00x = 0, // unknown format (also used for "breakpoint" opcode) 34 kFmt10x, // op 35 kFmt12x, // op vA, vB 36 kFmt11n, // op vA, #+B 37 kFmt11x, // op vAA 38 kFmt10t, // op +AA 39 kFmt20bc, // [opt] op AA, thing@BBBB 40 kFmt20t, // op +AAAA 41 kFmt22x, // op vAA, vBBBB 42 kFmt21t, // op vAA, +BBBB 43 kFmt21s, // op vAA, #+BBBB 44 kFmt21h, // op vAA, #+BBBB00000[00000000] 45 kFmt21c, // op vAA, thing@BBBB 46 kFmt23x, // op vAA, vBB, vCC 47 kFmt22b, // op vAA, vBB, #+CC 48 kFmt22t, // op vA, vB, +CCCC 49 kFmt22s, // op vA, vB, #+CCCC 50 kFmt22c, // op vA, vB, thing@CCCC 51 kFmt22cs, // [opt] op vA, vB, field offset CCCC 52 kFmt30t, // op +AAAAAAAA 53 kFmt32x, // op vAAAA, vBBBB 54 kFmt31i, // op vAA, #+BBBBBBBB 55 kFmt31t, // op vAA, +BBBBBBBB 56 kFmt31c, // op vAA, string@BBBBBBBB 57 kFmt35c, // op {vC,vD,vE,vF,vG}, thing@BBBB 58 kFmt35ms, // [opt] invoke-virtual+super 59 kFmt3rc, // op {vCCCC .. v(CCCC+AA-1)}, thing@BBBB 60 kFmt3rms, // [opt] invoke-virtual+super/range 61 kFmt51l, // op vAA, #+BBBBBBBBBBBBBBBB 62 kFmt35mi, // [opt] inline invoke 63 kFmt3rmi, // [opt] inline invoke/range 64 }; 65 66 /* 67 * Types of indexed reference that are associated with opcodes whose 68 * formats include such an indexed reference (e.g., 21c and 35c). 69 */ 70 enum InstructionIndexType { 71 kIndexUnknown = 0, 72 kIndexNone, // has no index 73 kIndexVaries, // "It depends." Used for throw-verification-error 74 kIndexTypeRef, // type reference index 75 kIndexStringRef, // string reference index 76 kIndexMethodRef, // method reference index 77 kIndexFieldRef, // field reference index 78 kIndexInlineMethod, // inline method index (for inline linked methods) 79 kIndexVtableOffset, // vtable offset (for static linked methods) 80 kIndexFieldOffset // field offset (for static linked fields) 81 }; 82 83 /* 84 * Instruction width implied by an opcode's format; a value in the 85 * range 0 to 5. Note that there are special "pseudo-instructions" 86 * which are used to encode switch and data tables, and these don't 87 * have a fixed width. See dexGetWidthFromInstruction(), below. 88 */ 89 typedef u1 InstructionWidth; 90 91 /* 92 * Opcode control flow flags, used by the verifier and JIT. 93 */ 94 typedef u1 OpcodeFlags; 95 enum OpcodeFlagsBits { 96 kInstrCanBranch = 1, // conditional or unconditional branch 97 kInstrCanContinue = 1 << 1, // flow can continue to next statement 98 kInstrCanSwitch = 1 << 2, // switch statement 99 kInstrCanThrow = 1 << 3, // could cause an exception to be thrown 100 kInstrCanReturn = 1 << 4, // returns, no additional statements 101 kInstrInvoke = 1 << 5, // a flavor of invoke 102 }; 103 104 /* 105 * Struct that includes a pointer to each of the opcode information 106 * tables. 107 * 108 * Note: We use "u1*" here instead of the names of the enumerated 109 * types to guarantee that elements don't use much space. We hold out 110 * hope for a standard way to indicate the size of an enumerated type 111 * that works for both C and C++, but in the mean time, this will 112 * suffice. 113 */ 114 struct InstructionInfoTables { 115 u1* formats; /* InstructionFormat elements */ 116 u1* indexTypes; /* InstructionIndexType elements */ 117 OpcodeFlags* flags; 118 InstructionWidth* widths; 119 }; 120 121 /* 122 * Global InstructionInfoTables struct. 123 */ 124 extern InstructionInfoTables gDexOpcodeInfo; 125 126 /* 127 * Holds the contents of a decoded instruction. 128 */ 129 struct DecodedInstruction { 130 u4 vA; 131 u4 vB; 132 u8 vB_wide; /* for kFmt51l */ 133 u4 vC; 134 u4 arg[5]; /* vC/D/E/F/G in invoke or filled-new-array */ 135 Opcode opcode; 136 InstructionIndexType indexType; 137 }; 138 139 /* 140 * Return the instruction width of the specified opcode, or 0 if not defined. 141 */ 142 DEX_INLINE size_t dexGetWidthFromOpcode(Opcode opcode) 143 { 144 assert((u4) opcode < kNumPackedOpcodes); 145 return gDexOpcodeInfo.widths[opcode]; 146 } 147 148 /* 149 * Return the width of the specified instruction, or 0 if not defined. Also 150 * works for special OP_NOP entries, including switch statement data tables 151 * and array data. 152 */ 153 size_t dexGetWidthFromInstruction(const u2* insns); 154 155 /* 156 * Returns the flags for the specified opcode. 157 */ 158 DEX_INLINE OpcodeFlags dexGetFlagsFromOpcode(Opcode opcode) 159 { 160 assert((u4) opcode < kNumPackedOpcodes); 161 return gDexOpcodeInfo.flags[opcode]; 162 } 163 164 /* 165 * Returns true if the given flags represent a goto (unconditional branch). 166 */ 167 DEX_INLINE bool dexIsGoto(OpcodeFlags flags) 168 { 169 return (flags & (kInstrCanBranch | kInstrCanContinue)) == kInstrCanBranch; 170 } 171 172 /* 173 * Return the instruction format for the specified opcode. 174 */ 175 DEX_INLINE InstructionFormat dexGetFormatFromOpcode(Opcode opcode) 176 { 177 assert((u4) opcode < kNumPackedOpcodes); 178 return (InstructionFormat) gDexOpcodeInfo.formats[opcode]; 179 } 180 181 /* 182 * Return the instruction index type for the specified opcode. 183 */ 184 DEX_INLINE InstructionIndexType dexGetIndexTypeFromOpcode(Opcode opcode) 185 { 186 assert((u4) opcode < kNumPackedOpcodes); 187 return (InstructionIndexType) gDexOpcodeInfo.indexTypes[opcode]; 188 } 189 190 /* 191 * Decode the instruction pointed to by "insns". 192 */ 193 void dexDecodeInstruction(const u2* insns, DecodedInstruction* pDec); 194 195 #endif // LIBDEX_INSTRUTILS_H_ 196
