2 * Copyright (C) 2008 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
18 * Dalvik instruction utility functions.
20 #ifndef LIBDEX_INSTRUTILS_H_
21 #define LIBDEX_INSTRUTILS_H_
24 #include "DexOpcodes.h"
27 * Possible instruction formats associated with Dalvik opcodes.
29 * See the file opcode-gen/README.txt for information about updating
30 * opcodes and instruction formats.
32 enum InstructionFormat {
33 kFmt00x = 0, // unknown format (also used for "breakpoint" opcode)
36 kFmt11n, // op vA, #+B
39 kFmt20bc, // [opt] op AA, thing@BBBB
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
67 * Types of indexed reference that are associated with opcodes whose
68 * formats include such an indexed reference (e.g., 21c and 35c).
70 enum InstructionIndexType {
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)
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.
89 typedef u1 InstructionWidth;
92 * Opcode control flow flags, used by the verifier and JIT.
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
105 * Struct that includes a pointer to each of the opcode information
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
114 struct InstructionInfoTables {
115 u1* formats; /* InstructionFormat elements */
116 u1* indexTypes; /* InstructionIndexType elements */
118 InstructionWidth* widths;
122 * Global InstructionInfoTables struct.
124 extern InstructionInfoTables gDexOpcodeInfo;
127 * Holds the contents of a decoded instruction.
129 struct DecodedInstruction {
132 u8 vB_wide; /* for kFmt51l */
134 u4 arg[5]; /* vC/D/E/F/G in invoke or filled-new-array */
136 InstructionIndexType indexType;
140 * Return the instruction width of the specified opcode, or 0 if not defined.
142 DEX_INLINE size_t dexGetWidthFromOpcode(Opcode opcode)
144 assert((u4) opcode < kNumPackedOpcodes);
145 return gDexOpcodeInfo.widths[opcode];
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
153 size_t dexGetWidthFromInstruction(const u2* insns);
156 * Returns the flags for the specified opcode.
158 DEX_INLINE OpcodeFlags dexGetFlagsFromOpcode(Opcode opcode)
160 assert((u4) opcode < kNumPackedOpcodes);
161 return gDexOpcodeInfo.flags[opcode];
165 * Returns true if the given flags represent a goto (unconditional branch).
167 DEX_INLINE bool dexIsGoto(OpcodeFlags flags)
169 return (flags & (kInstrCanBranch | kInstrCanContinue)) == kInstrCanBranch;
173 * Return the instruction format for the specified opcode.
175 DEX_INLINE InstructionFormat dexGetFormatFromOpcode(Opcode opcode)
177 assert((u4) opcode < kNumPackedOpcodes);
178 return (InstructionFormat) gDexOpcodeInfo.formats[opcode];
182 * Return the instruction index type for the specified opcode.
184 DEX_INLINE InstructionIndexType dexGetIndexTypeFromOpcode(Opcode opcode)
186 assert((u4) opcode < kNumPackedOpcodes);
187 return (InstructionIndexType) gDexOpcodeInfo.indexTypes[opcode];
191 * Decode the instruction pointed to by "insns".
193 void dexDecodeInstruction(const u2* insns, DecodedInstruction* pDec);
195 #endif // LIBDEX_INSTRUTILS_H_