Java tutorial
// ASM: a very small and fast Java bytecode manipulation framework // Copyright (c) 2000-2011 INRIA, France Telecom // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // 1. Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // 2. Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // 3. Neither the name of the copyright holders nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF // THE POSSIBILITY OF SUCH DAMAGE. package org.springframework.asm; /** * The JVM opcodes, access flags and array type codes. This interface does not define all the JVM * opcodes because some opcodes are automatically handled. For example, the xLOAD and xSTORE opcodes * are automatically replaced by xLOAD_n and xSTORE_n opcodes when possible. The xLOAD_n and * xSTORE_n opcodes are therefore not defined in this interface. Likewise for LDC, automatically * replaced by LDC_W or LDC2_W when necessary, WIDE, GOTO_W and JSR_W. * * @see <a href="https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-6.html">JVMS 6</a> * @author Eric Bruneton * @author Eugene Kuleshov */ // DontCheck(InterfaceIsType): can't be fixed (for backward binary compatibility). public interface Opcodes { // ASM API versions. int ASM4 = 4 << 16 | 0 << 8; int ASM5 = 5 << 16 | 0 << 8; int ASM6 = 6 << 16 | 0 << 8; int ASM7 = 7 << 16 | 0 << 8; /* * Internal flags used to redirect calls to deprecated methods. For instance, if a visitOldStuff * method in API_OLD is deprecated and replaced with visitNewStuff in API_NEW, then the * redirection should be done as follows: * * <pre> * public class StuffVisitor { * ... * * @Deprecated public void visitOldStuff(int arg, ...) { * // SOURCE_DEPRECATED means "a call from a deprecated method using the old 'api' value". * visitNewStuf(arg | (api < API_NEW ? SOURCE_DEPRECATED : 0), ...); * } * * public void visitNewStuff(int argAndSource, ...) { * if (api < API_NEW && (argAndSource & SOURCE_DEPRECATED) == 0) { * visitOldStuff(argAndSource, ...); * } else { * int arg = argAndSource & ~SOURCE_MASK; * [ do stuff ] * } * } * } * </pre> * * <p>If 'api' is equal to API_NEW, there are two cases: * * <ul> * <li>call visitNewStuff: the redirection test is skipped and 'do stuff' is executed directly. * <li>call visitOldSuff: the source is not set to SOURCE_DEPRECATED before calling * visitNewStuff, but the redirection test is skipped anyway in visitNewStuff, which * directly executes 'do stuff'. * </ul> * * <p>If 'api' is equal to API_OLD, there are two cases: * * <ul> * <li>call visitOldSuff: the source is set to SOURCE_DEPRECATED before calling visitNewStuff. * Because of this visitNewStuff does not redirect back to visitOldStuff, and instead * executes 'do stuff'. * <li>call visitNewStuff: the call is redirected to visitOldStuff because the source is 0. * visitOldStuff now sets the source to SOURCE_DEPRECATED and calls visitNewStuff back. This * time visitNewStuff does not redirect the call, and instead executes 'do stuff'. * </ul> * * <h1>User subclasses</h1> * * <p>If a user subclass overrides one of these methods, there are only two cases: either 'api' is * API_OLD and visitOldStuff is overridden (and visitNewStuff is not), or 'api' is API_NEW or * more, and visitNewStuff is overridden (and visitOldStuff is not). Any other case is a user * programming error. * * <p>If 'api' is equal to API_NEW, the class hierarchy is equivalent to * * <pre> * public class StuffVisitor { * @Deprecated public void visitOldStuff(int arg, ...) { visitNewStuf(arg, ...); } * public void visitNewStuff(int arg, ...) { [ do stuff ] } * } * class UserStuffVisitor extends StuffVisitor { * @Override public void visitNewStuff(int arg, ...) { * super.visitNewStuff(int arg, ...); // optional * [ do user stuff ] * } * } * </pre> * * <p>It is then obvious that whether visitNewStuff or visitOldStuff is called, 'do stuff' and 'do * user stuff' will be executed, in this order. * * <p>If 'api' is equal to API_OLD, the class hierarchy is equivalent to * * <pre> * public class StuffVisitor { * @Deprecated public void visitOldStuff(int arg, ...) { * visitNewStuf(arg | SOURCE_DEPRECATED, ...); * } * public void visitNewStuff(int argAndSource...) { * if ((argAndSource & SOURCE_DEPRECATED) == 0) { * visitOldStuff(argAndSource, ...); * } else { * int arg = argAndSource & ~SOURCE_MASK; * [ do stuff ] * } * } * } * class UserStuffVisitor extends StuffVisitor { * @Override public void visitOldStuff(int arg, ...) { * super.visitOldStuff(int arg, ...); // optional * [ do user stuff ] * } * } * </pre> * * <p>and there are two cases: * * <ul> * <li>call visitOldSuff: in the call to super.visitOldStuff, the source is set to * SOURCE_DEPRECATED and visitNewStuff is called. Here 'do stuff' is run because the source * was previously set to SOURCE_DEPRECATED, and execution eventually returns to * UserStuffVisitor.visitOldStuff, where 'do user stuff' is run. * <li>call visitNewStuff: the call is redirected to UserStuffVisitor.visitOldStuff because the * source is 0. Execution continues as in the previous case, resulting in 'do stuff' and 'do * user stuff' being executed, in this order. * </ul> * * <h1>ASM subclasses</h1> * * <p>In ASM packages, subclasses of StuffVisitor can typically be sub classed again by the user, * and can be used with API_OLD or API_NEW. Because of this, if such a subclass must override * visitNewStuff, it must do so in the following way (and must not override visitOldStuff): * * <pre> * public class AsmStuffVisitor extends StuffVisitor { * @Override public void visitNewStuff(int argAndSource, ...) { * if (api < API_NEW && (argAndSource & SOURCE_DEPRECATED) == 0) { * super.visitNewStuff(argAndSource, ...); * return; * } * super.visitNewStuff(argAndSource, ...); // optional * int arg = argAndSource & ~SOURCE_MASK; * [ do other stuff ] * } * } * </pre> * * <p>If a user class extends this with 'api' equal to API_NEW, the class hierarchy is equivalent * to * * <pre> * public class StuffVisitor { * @Deprecated public void visitOldStuff(int arg, ...) { visitNewStuf(arg, ...); } * public void visitNewStuff(int arg, ...) { [ do stuff ] } * } * public class AsmStuffVisitor extends StuffVisitor { * @Override public void visitNewStuff(int arg, ...) { * super.visitNewStuff(arg, ...); * [ do other stuff ] * } * } * class UserStuffVisitor extends StuffVisitor { * @Override public void visitNewStuff(int arg, ...) { * super.visitNewStuff(int arg, ...); * [ do user stuff ] * } * } * </pre> * * <p>It is then obvious that whether visitNewStuff or visitOldStuff is called, 'do stuff', 'do * other stuff' and 'do user stuff' will be executed, in this order. If, on the other hand, a user * class extends AsmStuffVisitor with 'api' equal to API_OLD, the class hierarchy is equivalent to * * <pre> * public class StuffVisitor { * @Deprecated public void visitOldStuff(int arg, ...) { * visitNewStuf(arg | SOURCE_DEPRECATED, ...); * } * public void visitNewStuff(int argAndSource, ...) { * if ((argAndSource & SOURCE_DEPRECATED) == 0) { * visitOldStuff(argAndSource, ...); * } else { * int arg = argAndSource & ~SOURCE_MASK; * [ do stuff ] * } * } * } * public class AsmStuffVisitor extends StuffVisitor { * @Override public void visitNewStuff(int argAndSource, ...) { * if ((argAndSource & SOURCE_DEPRECATED) == 0) { * super.visitNewStuff(argAndSource, ...); * return; * } * super.visitNewStuff(argAndSource, ...); // optional * int arg = argAndSource & ~SOURCE_MASK; * [ do other stuff ] * } * } * class UserStuffVisitor extends StuffVisitor { * @Override public void visitOldStuff(int arg, ...) { * super.visitOldStuff(arg, ...); * [ do user stuff ] * } * } * </pre> * * <p>and, here again, whether visitNewStuff or visitOldStuff is called, 'do stuff', 'do other * stuff' and 'do user stuff' will be executed, in this order (exercise left to the reader). * * <h1>Notes</h1> * * <ul> * <li>the SOURCE_DEPRECATED flag is set only if 'api' is API_OLD, just before calling * visitNewStuff. By hypothesis, this method is not overridden by the user. Therefore, user * classes can never see this flag. Only ASM subclasses must take care of extracting the * actual argument value by clearing the source flags. * <li>because the SOURCE_DEPRECATED flag is immediately cleared in the caller, the caller can * call visitOldStuff or visitNewStuff (in 'do stuff' and 'do user stuff') on a delegate * visitor without any risks (breaking the redirection logic, "leaking" the flag, etc). * <li>all the scenarios discussed above are unit tested in MethodVisitorTest. * </ul> */ int SOURCE_DEPRECATED = 0x100; int SOURCE_MASK = SOURCE_DEPRECATED; // Java ClassFile versions (the minor version is stored in the 16 most significant bits, and the // major version in the 16 least significant bits). int V1_1 = 3 << 16 | 45; int V1_2 = 0 << 16 | 46; int V1_3 = 0 << 16 | 47; int V1_4 = 0 << 16 | 48; int V1_5 = 0 << 16 | 49; int V1_6 = 0 << 16 | 50; int V1_7 = 0 << 16 | 51; int V1_8 = 0 << 16 | 52; int V9 = 0 << 16 | 53; int V10 = 0 << 16 | 54; int V11 = 0 << 16 | 55; int V12 = 0 << 16 | 56; int V13 = 0 << 16 | 57; int V14 = 0 << 16 | 58; /** * Version flag indicating that the class is using 'preview' features. * * <p>{@code version & V_PREVIEW == V_PREVIEW} tests if a version is flagged with {@code * V_PREVIEW}. */ int V_PREVIEW = 0xFFFF0000; // Access flags values, defined in // - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.1-200-E.1 // - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.5-200-A.1 // - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.6-200-A.1 // - https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.25 int ACC_PUBLIC = 0x0001; // class, field, method int ACC_PRIVATE = 0x0002; // class, field, method int ACC_PROTECTED = 0x0004; // class, field, method int ACC_STATIC = 0x0008; // field, method int ACC_FINAL = 0x0010; // class, field, method, parameter int ACC_SUPER = 0x0020; // class int ACC_SYNCHRONIZED = 0x0020; // method int ACC_OPEN = 0x0020; // module int ACC_TRANSITIVE = 0x0020; // module requires int ACC_VOLATILE = 0x0040; // field int ACC_BRIDGE = 0x0040; // method int ACC_STATIC_PHASE = 0x0040; // module requires int ACC_VARARGS = 0x0080; // method int ACC_TRANSIENT = 0x0080; // field int ACC_NATIVE = 0x0100; // method int ACC_INTERFACE = 0x0200; // class int ACC_ABSTRACT = 0x0400; // class, method int ACC_STRICT = 0x0800; // method int ACC_SYNTHETIC = 0x1000; // class, field, method, parameter, module * int ACC_ANNOTATION = 0x2000; // class int ACC_ENUM = 0x4000; // class(?) field inner int ACC_MANDATED = 0x8000; // parameter, module, module * int ACC_MODULE = 0x8000; // class // ASM specific access flags. // WARNING: the 16 least significant bits must NOT be used, to avoid conflicts with standard // access flags, and also to make sure that these flags are automatically filtered out when // written in class files (because access flags are stored using 16 bits only). int ACC_DEPRECATED = 0x20000; // class, field, method // Possible values for the type operand of the NEWARRAY instruction. // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-6.html#jvms-6.5.newarray. int T_BOOLEAN = 4; int T_CHAR = 5; int T_FLOAT = 6; int T_DOUBLE = 7; int T_BYTE = 8; int T_SHORT = 9; int T_INT = 10; int T_LONG = 11; // Possible values for the reference_kind field of CONSTANT_MethodHandle_info structures. // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.4.8. int H_GETFIELD = 1; int H_GETSTATIC = 2; int H_PUTFIELD = 3; int H_PUTSTATIC = 4; int H_INVOKEVIRTUAL = 5; int H_INVOKESTATIC = 6; int H_INVOKESPECIAL = 7; int H_NEWINVOKESPECIAL = 8; int H_INVOKEINTERFACE = 9; // ASM specific stack map frame types, used in {@link ClassVisitor#visitFrame}. /** An expanded frame. See {@link ClassReader#EXPAND_FRAMES}. */ int F_NEW = -1; /** A compressed frame with complete frame data. */ int F_FULL = 0; /** * A compressed frame where locals are the same as the locals in the previous frame, except that * additional 1-3 locals are defined, and with an empty stack. */ int F_APPEND = 1; /** * A compressed frame where locals are the same as the locals in the previous frame, except that * the last 1-3 locals are absent and with an empty stack. */ int F_CHOP = 2; /** * A compressed frame with exactly the same locals as the previous frame and with an empty stack. */ int F_SAME = 3; /** * A compressed frame with exactly the same locals as the previous frame and with a single value * on the stack. */ int F_SAME1 = 4; // Standard stack map frame element types, used in {@link ClassVisitor#visitFrame}. Integer TOP = Frame.ITEM_TOP; Integer INTEGER = Frame.ITEM_INTEGER; Integer FLOAT = Frame.ITEM_FLOAT; Integer DOUBLE = Frame.ITEM_DOUBLE; Integer LONG = Frame.ITEM_LONG; Integer NULL = Frame.ITEM_NULL; Integer UNINITIALIZED_THIS = Frame.ITEM_UNINITIALIZED_THIS; // The JVM opcode values (with the MethodVisitor method name used to visit them in comment, and // where '-' means 'same method name as on the previous line'). // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-6.html. int NOP = 0; // visitInsn int ACONST_NULL = 1; // - int ICONST_M1 = 2; // - int ICONST_0 = 3; // - int ICONST_1 = 4; // - int ICONST_2 = 5; // - int ICONST_3 = 6; // - int ICONST_4 = 7; // - int ICONST_5 = 8; // - int LCONST_0 = 9; // - int LCONST_1 = 10; // - int FCONST_0 = 11; // - int FCONST_1 = 12; // - int FCONST_2 = 13; // - int DCONST_0 = 14; // - int DCONST_1 = 15; // - int BIPUSH = 16; // visitIntInsn int SIPUSH = 17; // - int LDC = 18; // visitLdcInsn int ILOAD = 21; // visitVarInsn int LLOAD = 22; // - int FLOAD = 23; // - int DLOAD = 24; // - int ALOAD = 25; // - int IALOAD = 46; // visitInsn int LALOAD = 47; // - int FALOAD = 48; // - int DALOAD = 49; // - int AALOAD = 50; // - int BALOAD = 51; // - int CALOAD = 52; // - int SALOAD = 53; // - int ISTORE = 54; // visitVarInsn int LSTORE = 55; // - int FSTORE = 56; // - int DSTORE = 57; // - int ASTORE = 58; // - int IASTORE = 79; // visitInsn int LASTORE = 80; // - int FASTORE = 81; // - int DASTORE = 82; // - int AASTORE = 83; // - int BASTORE = 84; // - int CASTORE = 85; // - int SASTORE = 86; // - int POP = 87; // - int POP2 = 88; // - int DUP = 89; // - int DUP_X1 = 90; // - int DUP_X2 = 91; // - int DUP2 = 92; // - int DUP2_X1 = 93; // - int DUP2_X2 = 94; // - int SWAP = 95; // - int IADD = 96; // - int LADD = 97; // - int FADD = 98; // - int DADD = 99; // - int ISUB = 100; // - int LSUB = 101; // - int FSUB = 102; // - int DSUB = 103; // - int IMUL = 104; // - int LMUL = 105; // - int FMUL = 106; // - int DMUL = 107; // - int IDIV = 108; // - int LDIV = 109; // - int FDIV = 110; // - int DDIV = 111; // - int IREM = 112; // - int LREM = 113; // - int FREM = 114; // - int DREM = 115; // - int INEG = 116; // - int LNEG = 117; // - int FNEG = 118; // - int DNEG = 119; // - int ISHL = 120; // - int LSHL = 121; // - int ISHR = 122; // - int LSHR = 123; // - int IUSHR = 124; // - int LUSHR = 125; // - int IAND = 126; // - int LAND = 127; // - int IOR = 128; // - int LOR = 129; // - int IXOR = 130; // - int LXOR = 131; // - int IINC = 132; // visitIincInsn int I2L = 133; // visitInsn int I2F = 134; // - int I2D = 135; // - int L2I = 136; // - int L2F = 137; // - int L2D = 138; // - int F2I = 139; // - int F2L = 140; // - int F2D = 141; // - int D2I = 142; // - int D2L = 143; // - int D2F = 144; // - int I2B = 145; // - int I2C = 146; // - int I2S = 147; // - int LCMP = 148; // - int FCMPL = 149; // - int FCMPG = 150; // - int DCMPL = 151; // - int DCMPG = 152; // - int IFEQ = 153; // visitJumpInsn int IFNE = 154; // - int IFLT = 155; // - int IFGE = 156; // - int IFGT = 157; // - int IFLE = 158; // - int IF_ICMPEQ = 159; // - int IF_ICMPNE = 160; // - int IF_ICMPLT = 161; // - int IF_ICMPGE = 162; // - int IF_ICMPGT = 163; // - int IF_ICMPLE = 164; // - int IF_ACMPEQ = 165; // - int IF_ACMPNE = 166; // - int GOTO = 167; // - int JSR = 168; // - int RET = 169; // visitVarInsn int TABLESWITCH = 170; // visiTableSwitchInsn int LOOKUPSWITCH = 171; // visitLookupSwitch int IRETURN = 172; // visitInsn int LRETURN = 173; // - int FRETURN = 174; // - int DRETURN = 175; // - int ARETURN = 176; // - int RETURN = 177; // - int GETSTATIC = 178; // visitFieldInsn int PUTSTATIC = 179; // - int GETFIELD = 180; // - int PUTFIELD = 181; // - int INVOKEVIRTUAL = 182; // visitMethodInsn int INVOKESPECIAL = 183; // - int INVOKESTATIC = 184; // - int INVOKEINTERFACE = 185; // - int INVOKEDYNAMIC = 186; // visitInvokeDynamicInsn int NEW = 187; // visitTypeInsn int NEWARRAY = 188; // visitIntInsn int ANEWARRAY = 189; // visitTypeInsn int ARRAYLENGTH = 190; // visitInsn int ATHROW = 191; // - int CHECKCAST = 192; // visitTypeInsn int INSTANCEOF = 193; // - int MONITORENTER = 194; // visitInsn int MONITOREXIT = 195; // - int MULTIANEWARRAY = 197; // visitMultiANewArrayInsn int IFNULL = 198; // visitJumpInsn int IFNONNULL = 199; // - }