Class CheckMethodAdapter


  • public class CheckMethodAdapter
    extends MethodVisitor
    A MethodVisitor that checks that its methods are properly used. More precisely this method adapter checks each instruction individually, i.e., each visit method checks some preconditions based only on its arguments - such as the fact that the given opcode is correct for a given visit method. This adapter can also perform some basic data flow checks (more precisely those that can be performed without the full class hierarchy - see BasicVerifier). For instance in a method whose signature is void m (), the invalid instruction IRETURN, or the invalid sequence IADD L2I will be detected if the data flow checks are enabled. These checks are enabled by using the CheckMethodAdapter(int,String,String,MethodVisitor,Map) constructor. They are not performed if any other constructor is used.
    Author:
    Eric Bruneton
    • Field Detail

      • version

        public int version
        The class version number.
    • Constructor Detail

      • CheckMethodAdapter

        public CheckMethodAdapter​(int access,
                                  java.lang.String name,
                                  java.lang.String desc,
                                  MethodVisitor cmv,
                                  java.util.Map<Label,​java.lang.Integer> labels)
        Constructs a new CheckMethodAdapter object. This method adapter will perform basic data flow checks. For instance in a method whose signature is void m (), the invalid instruction IRETURN, or the invalid sequence IADD L2I will be detected.
        Parameters:
        access - the method's access flags.
        name - the method's name.
        desc - the method's descriptor (see Type).
        cmv - the method visitor to which this adapter must delegate calls.
        labels - a map of already visited labels (in other methods).
    • Method Detail

      • visitParameter

        public void visitParameter​(java.lang.String name,
                                   int access)
        Description copied from class: MethodVisitor
        Visits a parameter of this method.
        Overrides:
        visitParameter in class MethodVisitor
        Parameters:
        name - parameter name or null if none is provided.
        access - the parameter's access flags, only ACC_FINAL, ACC_SYNTHETIC or/and ACC_MANDATED are allowed (see Opcodes).
      • visitAnnotation

        public AnnotationVisitor visitAnnotation​(java.lang.String desc,
                                                 boolean visible)
        Description copied from class: MethodVisitor
        Visits an annotation of this method.
        Overrides:
        visitAnnotation in class MethodVisitor
        Parameters:
        desc - the class descriptor of the annotation class.
        visible - true if the annotation is visible at runtime.
        Returns:
        a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
      • visitTypeAnnotation

        public AnnotationVisitor visitTypeAnnotation​(int typeRef,
                                                     TypePath typePath,
                                                     java.lang.String desc,
                                                     boolean visible)
        Description copied from class: MethodVisitor
        Visits an annotation on a type in the method signature.
        Overrides:
        visitTypeAnnotation in class MethodVisitor
        Parameters:
        typeRef - a reference to the annotated type. The sort of this type reference must be METHOD_TYPE_PARAMETER, METHOD_TYPE_PARAMETER_BOUND, METHOD_RETURN, METHOD_RECEIVER, METHOD_FORMAL_PARAMETER or THROWS. See TypeReference.
        typePath - the path to the annotated type argument, wildcard bound, array element type, or static inner type within 'typeRef'. May be null if the annotation targets 'typeRef' as a whole.
        desc - the class descriptor of the annotation class.
        visible - true if the annotation is visible at runtime.
        Returns:
        a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
      • visitAnnotationDefault

        public AnnotationVisitor visitAnnotationDefault()
        Description copied from class: MethodVisitor
        Visits the default value of this annotation interface method.
        Overrides:
        visitAnnotationDefault in class MethodVisitor
        Returns:
        a visitor to the visit the actual default value of this annotation interface method, or null if this visitor is not interested in visiting this default value. The 'name' parameters passed to the methods of this annotation visitor are ignored. Moreover, exacly one visit method must be called on this annotation visitor, followed by visitEnd.
      • visitParameterAnnotation

        public AnnotationVisitor visitParameterAnnotation​(int parameter,
                                                          java.lang.String desc,
                                                          boolean visible)
        Description copied from class: MethodVisitor
        Visits an annotation of a parameter this method.
        Overrides:
        visitParameterAnnotation in class MethodVisitor
        Parameters:
        parameter - the parameter index.
        desc - the class descriptor of the annotation class.
        visible - true if the annotation is visible at runtime.
        Returns:
        a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
      • visitCode

        public void visitCode()
        Description copied from class: MethodVisitor
        Starts the visit of the method's code, if any (i.e. non abstract method).
        Overrides:
        visitCode in class MethodVisitor
      • visitFrame

        public void visitFrame​(int type,
                               int nLocal,
                               java.lang.Object[] local,
                               int nStack,
                               java.lang.Object[] stack)
        Description copied from class: MethodVisitor
        Visits the current state of the local variables and operand stack elements. This method must(*) be called just before any instruction i that follows an unconditional branch instruction such as GOTO or THROW, that is the target of a jump instruction, or that starts an exception handler block. The visited types must describe the values of the local variables and of the operand stack elements just before i is executed.

        (*) this is mandatory only for classes whose version is greater than or equal to V1_6.

        The frames of a method must be given either in expanded form, or in compressed form (all frames must use the same format, i.e. you must not mix expanded and compressed frames within a single method):
        • In expanded form, all frames must have the F_NEW type.
        • In compressed form, frames are basically "deltas" from the state of the previous frame:
          • Opcodes.F_SAME representing frame with exactly the same locals as the previous frame and with the empty stack.
          • Opcodes.F_SAME1 representing frame with exactly the same locals as the previous frame and with single value on the stack ( nStack is 1 and stack[0] contains value for the type of the stack item).
          • Opcodes.F_APPEND representing frame with current locals are the same as the locals in the previous frame, except that additional locals are defined (nLocal is 1, 2 or 3 and local elements contains values representing added types).
          • Opcodes.F_CHOP representing frame with current locals are the same as the locals in the previous frame, except that the last 1-3 locals are absent and with the empty stack (nLocals is 1, 2 or 3).
          • Opcodes.F_FULL representing complete frame data.

        In both cases the first frame, corresponding to the method's parameters and access flags, is implicit and must not be visited. Also, it is illegal to visit two or more frames for the same code location (i.e., at least one instruction must be visited between two calls to visitFrame).
        Overrides:
        visitFrame in class MethodVisitor
        Parameters:
        type - the type of this stack map frame. Must be Opcodes.F_NEW for expanded frames, or Opcodes.F_FULL, Opcodes.F_APPEND, Opcodes.F_CHOP, Opcodes.F_SAME or Opcodes.F_APPEND, Opcodes.F_SAME1 for compressed frames.
        nLocal - the number of local variables in the visited frame.
        local - the local variable types in this frame. This array must not be modified. Primitive types are represented by Opcodes.TOP, Opcodes.INTEGER, Opcodes.FLOAT, Opcodes.LONG, Opcodes.DOUBLE,Opcodes.NULL or Opcodes.UNINITIALIZED_THIS (long and double are represented by a single element). Reference types are represented by String objects (representing internal names), and uninitialized types by Label objects (this label designates the NEW instruction that created this uninitialized value).
        nStack - the number of operand stack elements in the visited frame.
        stack - the operand stack types in this frame. This array must not be modified. Its content has the same format as the "local" array.
      • visitInsn

        public void visitInsn​(int opcode)
        Description copied from class: MethodVisitor
        Visits a zero operand instruction.
        Overrides:
        visitInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the instruction to be visited. This opcode is either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2, ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0, FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD, DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE, DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP, DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD, DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV, FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL, LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR, I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B, I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN, FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW, MONITORENTER, or MONITOREXIT.
      • visitVarInsn

        public void visitVarInsn​(int opcode,
                                 int var)
        Description copied from class: MethodVisitor
        Visits a local variable instruction. A local variable instruction is an instruction that loads or stores the value of a local variable.
        Overrides:
        visitVarInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the local variable instruction to be visited. This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE, LSTORE, FSTORE, DSTORE, ASTORE or RET.
        var - the operand of the instruction to be visited. This operand is the index of a local variable.
      • visitTypeInsn

        public void visitTypeInsn​(int opcode,
                                  java.lang.String type)
        Description copied from class: MethodVisitor
        Visits a type instruction. A type instruction is an instruction that takes the internal name of a class as parameter.
        Overrides:
        visitTypeInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the type instruction to be visited. This opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
        type - the operand of the instruction to be visited. This operand must be the internal name of an object or array class (see getInternalName).
      • visitFieldInsn

        public void visitFieldInsn​(int opcode,
                                   java.lang.String owner,
                                   java.lang.String name,
                                   java.lang.String desc)
        Description copied from class: MethodVisitor
        Visits a field instruction. A field instruction is an instruction that loads or stores the value of a field of an object.
        Overrides:
        visitFieldInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the type instruction to be visited. This opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
        owner - the internal name of the field's owner class (see getInternalName).
        name - the field's name.
        desc - the field's descriptor (see Type).
      • visitMethodInsn

        @Deprecated
        public void visitMethodInsn​(int opcode,
                                    java.lang.String owner,
                                    java.lang.String name,
                                    java.lang.String desc)
        Deprecated.
        Description copied from class: MethodVisitor
        Visits a method instruction. A method instruction is an instruction that invokes a method.
        Overrides:
        visitMethodInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or INVOKEINTERFACE.
        owner - the internal name of the method's owner class (see getInternalName).
        name - the method's name.
        desc - the method's descriptor (see Type).
      • visitMethodInsn

        public void visitMethodInsn​(int opcode,
                                    java.lang.String owner,
                                    java.lang.String name,
                                    java.lang.String desc,
                                    boolean itf)
        Description copied from class: MethodVisitor
        Visits a method instruction. A method instruction is an instruction that invokes a method.
        Overrides:
        visitMethodInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the type instruction to be visited. This opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC or INVOKEINTERFACE.
        owner - the internal name of the method's owner class (see getInternalName).
        name - the method's name.
        desc - the method's descriptor (see Type).
        itf - if the method's owner class is an interface.
      • visitInvokeDynamicInsn

        public void visitInvokeDynamicInsn​(java.lang.String name,
                                           java.lang.String desc,
                                           Handle bsm,
                                           java.lang.Object... bsmArgs)
        Description copied from class: MethodVisitor
        Visits an invokedynamic instruction.
        Overrides:
        visitInvokeDynamicInsn in class MethodVisitor
        Parameters:
        name - the method's name.
        desc - the method's descriptor (see Type).
        bsm - the bootstrap method.
        bsmArgs - the bootstrap method constant arguments. Each argument must be an Integer, Float, Long, Double, String, Type or Handle value. This method is allowed to modify the content of the array so a caller should expect that this array may change.
      • visitJumpInsn

        public void visitJumpInsn​(int opcode,
                                  Label label)
        Description copied from class: MethodVisitor
        Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.
        Overrides:
        visitJumpInsn in class MethodVisitor
        Parameters:
        opcode - the opcode of the type instruction to be visited. This opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ, IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ, IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
        label - the operand of the instruction to be visited. This operand is a label that designates the instruction to which the jump instruction may jump.
      • visitLabel

        public void visitLabel​(Label label)
        Description copied from class: MethodVisitor
        Visits a label. A label designates the instruction that will be visited just after it.
        Overrides:
        visitLabel in class MethodVisitor
        Parameters:
        label - a Label object.
      • visitLdcInsn

        public void visitLdcInsn​(java.lang.Object cst)
        Description copied from class: MethodVisitor
        Visits a LDC instruction. Note that new constant types may be added in future versions of the Java Virtual Machine. To easily detect new constant types, implementations of this method should check for unexpected constant types, like this:
         if (cst instanceof Integer) {
             // ...
         } else if (cst instanceof Float) {
             // ...
         } else if (cst instanceof Long) {
             // ...
         } else if (cst instanceof Double) {
             // ...
         } else if (cst instanceof String) {
             // ...
         } else if (cst instanceof Type) {
             int sort = ((Type) cst).getSort();
             if (sort == Type.OBJECT) {
                 // ...
             } else if (sort == Type.ARRAY) {
                 // ...
             } else if (sort == Type.METHOD) {
                 // ...
             } else {
                 // throw an exception
             }
         } else if (cst instanceof Handle) {
             // ...
         } else {
             // throw an exception
         }
         
        Overrides:
        visitLdcInsn in class MethodVisitor
        Parameters:
        cst - the constant to be loaded on the stack. This parameter must be a non null Integer, a Float, a Long, a Double, a String, a Type of OBJECT or ARRAY sort for .class constants, for classes whose version is 49.0, a Type of METHOD sort or a Handle for MethodType and MethodHandle constants, for classes whose version is 51.0.
      • visitIincInsn

        public void visitIincInsn​(int var,
                                  int increment)
        Description copied from class: MethodVisitor
        Visits an IINC instruction.
        Overrides:
        visitIincInsn in class MethodVisitor
        Parameters:
        var - index of the local variable to be incremented.
        increment - amount to increment the local variable by.
      • visitTableSwitchInsn

        public void visitTableSwitchInsn​(int min,
                                         int max,
                                         Label dflt,
                                         Label... labels)
        Description copied from class: MethodVisitor
        Visits a TABLESWITCH instruction.
        Overrides:
        visitTableSwitchInsn in class MethodVisitor
        Parameters:
        min - the minimum key value.
        max - the maximum key value.
        dflt - beginning of the default handler block.
        labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the min + i key.
      • visitLookupSwitchInsn

        public void visitLookupSwitchInsn​(Label dflt,
                                          int[] keys,
                                          Label[] labels)
        Description copied from class: MethodVisitor
        Visits a LOOKUPSWITCH instruction.
        Overrides:
        visitLookupSwitchInsn in class MethodVisitor
        Parameters:
        dflt - beginning of the default handler block.
        keys - the values of the keys.
        labels - beginnings of the handler blocks. labels[i] is the beginning of the handler block for the keys[i] key.
      • visitMultiANewArrayInsn

        public void visitMultiANewArrayInsn​(java.lang.String desc,
                                            int dims)
        Description copied from class: MethodVisitor
        Visits a MULTIANEWARRAY instruction.
        Overrides:
        visitMultiANewArrayInsn in class MethodVisitor
        Parameters:
        desc - an array type descriptor (see Type).
        dims - number of dimensions of the array to allocate.
      • visitTryCatchBlock

        public void visitTryCatchBlock​(Label start,
                                       Label end,
                                       Label handler,
                                       java.lang.String type)
        Description copied from class: MethodVisitor
        Visits a try catch block.
        Overrides:
        visitTryCatchBlock in class MethodVisitor
        Parameters:
        start - beginning of the exception handler's scope (inclusive).
        end - end of the exception handler's scope (exclusive).
        handler - beginning of the exception handler's code.
        type - internal name of the type of exceptions handled by the handler, or null to catch any exceptions (for "finally" blocks).
      • visitLocalVariable

        public void visitLocalVariable​(java.lang.String name,
                                       java.lang.String desc,
                                       java.lang.String signature,
                                       Label start,
                                       Label end,
                                       int index)
        Description copied from class: MethodVisitor
        Visits a local variable declaration.
        Overrides:
        visitLocalVariable in class MethodVisitor
        Parameters:
        name - the name of a local variable.
        desc - the type descriptor of this local variable.
        signature - the type signature of this local variable. May be null if the local variable type does not use generic types.
        start - the first instruction corresponding to the scope of this local variable (inclusive).
        end - the last instruction corresponding to the scope of this local variable (exclusive).
        index - the local variable's index.
      • visitLocalVariableAnnotation

        public AnnotationVisitor visitLocalVariableAnnotation​(int typeRef,
                                                              TypePath typePath,
                                                              Label[] start,
                                                              Label[] end,
                                                              int[] index,
                                                              java.lang.String desc,
                                                              boolean visible)
        Description copied from class: MethodVisitor
        Visits an annotation on a local variable type.
        Overrides:
        visitLocalVariableAnnotation in class MethodVisitor
        Parameters:
        typeRef - a reference to the annotated type. The sort of this type reference must be LOCAL_VARIABLE or RESOURCE_VARIABLE. See TypeReference.
        typePath - the path to the annotated type argument, wildcard bound, array element type, or static inner type within 'typeRef'. May be null if the annotation targets 'typeRef' as a whole.
        start - the fist instructions corresponding to the continuous ranges that make the scope of this local variable (inclusive).
        end - the last instructions corresponding to the continuous ranges that make the scope of this local variable (exclusive). This array must have the same size as the 'start' array.
        index - the local variable's index in each range. This array must have the same size as the 'start' array.
        desc - the class descriptor of the annotation class.
        visible - true if the annotation is visible at runtime.
        Returns:
        a visitor to visit the annotation values, or null if this visitor is not interested in visiting this annotation.
      • visitLineNumber

        public void visitLineNumber​(int line,
                                    Label start)
        Description copied from class: MethodVisitor
        Visits a line number declaration.
        Overrides:
        visitLineNumber in class MethodVisitor
        Parameters:
        line - a line number. This number refers to the source file from which the class was compiled.
        start - the first instruction corresponding to this line number.
      • visitMaxs

        public void visitMaxs​(int maxStack,
                              int maxLocals)
        Description copied from class: MethodVisitor
        Visits the maximum stack size and the maximum number of local variables of the method.
        Overrides:
        visitMaxs in class MethodVisitor
        Parameters:
        maxStack - maximum stack size of the method.
        maxLocals - maximum number of local variables for the method.
      • visitEnd

        public void visitEnd()
        Description copied from class: MethodVisitor
        Visits the end of the method. This method, which is the last one to be called, is used to inform the visitor that all the annotations and attributes of the method have been visited.
        Overrides:
        visitEnd in class MethodVisitor