Class MethodWriter
MethodVisitor
that generates a corresponding 'method_info' structure, as defined in the
Java Virtual Machine Specification (JVMS).- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final int
The access_flags field of the method_info JVMS structure.private final ByteVector
The 'code' field of the Code attribute.private final int
Indicates what must be computed.(package private) static final int
Indicates that all the stack map frames must be computed.(package private) static final int
Indicates that the stack map frames of type F_INSERT must be computed.(package private) static final int
Indicates that the maximum stack size and the maximum number of local variables must be computed, from scratch.(package private) static final int
Indicates that the maximum stack size and the maximum number of local variables must be computed, from the existing stack map frames.(package private) static final int
Indicates that nothing must be computed.private Label
The current basic block, i.e.private int[]
The current stack map frame.private int
The number of local variables in the last visited stack map frame.private ByteVector
The default_value field of the AnnotationDefault attribute, or null.private final String
The descriptor of this method.private final int
The descriptor_index field of the method_info JVMS structure.private final int[]
The exception_index_table array of the Exceptions attribute, or null.private Attribute
The first non standard attribute of this method.private Label
The first basic block of the method.private Attribute
The first non standard attribute of the Code attribute.private Handler
The first element in the exception handler list (used to generate the exception_table of the Code attribute).private boolean
Whether the bytecode of this method contains ASM specific instructions.private boolean
Whether this method contains subroutines.private int
The number of method parameters that can have runtime visible annotations, or 0.private Label
The last basic block of the method (in bytecode offset order).private int
The start offset of the last visited instruction.private AnnotationWriter
The last runtime invisible type annotation of the Code attribute.private AnnotationWriter
The last runtime visible type annotation of the Code attribute.private Handler
The last element in the exception handler list (used to generate the exception_table of the Code attribute).private AnnotationWriter
The last runtime invisible annotation of this method.private AnnotationWriter[]
The runtime invisible parameter annotations of this method.private AnnotationWriter
The last runtime invisible type annotation of this method.private AnnotationWriter
The last runtime visible annotation of this method.private AnnotationWriter[]
The runtime visible parameter annotations of this method.private AnnotationWriter
The last runtime visible type annotation of this method.private ByteVector
The line_number_table array of the LineNumberTable code attribute, or null.private int
The line_number_table_length field of the LineNumberTable code attribute.private ByteVector
The local_variable_table array of the LocalVariableTable code attribute, or null.private int
The local_variable_table_length field of the LocalVariableTable code attribute.private ByteVector
The local_variable_type_table array of the LocalVariableTypeTable code attribute, or null.private int
The local_variable_type_table_length field of the LocalVariableTypeTable code attribute.private int
The max_locals field of the Code attribute.private int
The maximum relative stack size after the last visited instruction.private int
The max_stack field of the Code attribute.private static final int
Indicates thatSTACK_SIZE_DELTA
is not applicable (not constant or never used).private final String
The name of this method.private final int
The name_index field of the method_info JVMS structure.private final int
The number_of_exceptions field of the Exceptions attribute.private ByteVector
The 'parameters' array of the MethodParameters attribute, or null.private int
The parameters_count field of the MethodParameters attribute.private int[]
The last frame that was written instackMapTableEntries
.private int
The bytecode offset of the last frame that was written instackMapTableEntries
.private int
The relative stack size after the last visited instruction.private final int
The signature_index field of the Signature attribute.private int
The length in bytes inSymbolTable.getSource()
which must be copied to get the method_info for this method (excluding its first 6 bytes for access_flags, name_index and descriptor_index).private int
The offset in bytes inSymbolTable.getSource()
from which the method_info for this method (excluding its first 6 bytes) must be copied, or 0.private static final int[]
The stack size variation corresponding to each JVM opcode.private ByteVector
The 'entries' array of the StackMapTable code attribute.private int
The number_of_entries field of the StackMapTable code attribute.private final SymbolTable
Where the constants used in this MethodWriter must be stored.private int
The number of method parameters that can have runtime visible annotations, or 0.Fields inherited from class org.objectweb.asm.MethodVisitor
api, mv
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Constructor Summary
ConstructorsConstructorDescriptionMethodWriter
(SymbolTable symbolTable, int access, String name, String descriptor, String signature, String[] exceptions, int compute) Constructs a newMethodWriter
. -
Method Summary
Modifier and TypeMethodDescriptionprivate void
addSuccessorToCurrentBasicBlock
(int info, Label successor) Adds a successor tocurrentBasicBlock
in the control flow graph.(package private) boolean
canCopyMethodAttributes
(ClassReader source, boolean hasSyntheticAttribute, boolean hasDeprecatedAttribute, int descriptorIndex, int signatureIndex, int exceptionsOffset) Returns whether the attributes of this method can be copied from the attributes of the given method (assuming there is no method visitor between the given ClassReader and this MethodWriter).(package private) final void
collectAttributePrototypes
(Attribute.Set attributePrototypes) Collects the attributes of this method into the given set of attribute prototypes.private void
Computes all the stack map frames of the method, from scratch.private void
Computes the maximum stack size of the method.(package private) int
Returns the size of the method_info JVMS structure generated by this MethodWriter.private void
Ends the current basic block.(package private) boolean
(package private) boolean
private void
putAbstractTypes
(int start, int end) Puts some abstract types ofcurrentFrame
instackMapTableEntries
, using the JVMS verification_type_info format used in StackMapTable attributes.private void
putFrame()
Compresses and writescurrentFrame
in a new StackMapTable entry.private void
putFrameType
(Object type) Puts the given public API frame element type instackMapTableEntries
, using the JVMS verification_type_info format used in StackMapTable attributes.(package private) void
putMethodInfo
(ByteVector output) Puts the content of the method_info JVMS structure generated by this MethodWriter into the given ByteVector.(package private) void
setMethodAttributesSource
(int methodInfoOffset, int methodInfoLength) Sets the source from which the attributes of this method will be copied.(package private) void
visitAbstractType
(int frameIndex, int abstractType) Sets an abstract type incurrentFrame
.void
visitAnnotableParameterCount
(int parameterCount, boolean visible) Visits the number of method parameters that can have annotations.visitAnnotation
(String descriptor, boolean visible) Visits an annotation of this method.Visits the default value of this annotation interface method.void
visitAttribute
(Attribute attribute) Visits a non standard attribute of this method.void
Starts the visit of the method's code, if any (i.e.void
visitEnd()
Visits the end of the method.void
visitFieldInsn
(int opcode, String owner, String name, String descriptor) Visits a field instruction.void
visitFrame
(int type, int numLocal, Object[] local, int numStack, Object[] stack) Visits the current state of the local variables and operand stack elements.(package private) void
Ends the visit ofcurrentFrame
by writing it in the StackMapTable entries and by updating the StackMapTable number_of_entries (except if the current frame is the first one, which is implicit in StackMapTable).(package private) int
visitFrameStart
(int offset, int numLocal, int numStack) Starts the visit of a new stack map frame, stored incurrentFrame
.void
visitIincInsn
(int varIndex, int increment) Visits an IINC instruction.void
visitInsn
(int opcode) Visits a zero operand instruction.visitInsnAnnotation
(int typeRef, TypePath typePath, String descriptor, boolean visible) Visits an annotation on an instruction.void
visitIntInsn
(int opcode, int operand) Visits an instruction with a single int operand.void
visitInvokeDynamicInsn
(String name, String descriptor, Handle bootstrapMethodHandle, Object... bootstrapMethodArguments) Visits an invokedynamic instruction.void
visitJumpInsn
(int opcode, Label label) Visits a jump instruction.void
visitLabel
(Label label) Visits a label.void
visitLdcInsn
(Object value) Visits a LDC instruction.void
visitLineNumber
(int line, Label start) Visits a line number declaration.void
visitLocalVariable
(String name, String descriptor, String signature, Label start, Label end, int index) Visits a local variable declaration.visitLocalVariableAnnotation
(int typeRef, TypePath typePath, Label[] start, Label[] end, int[] index, String descriptor, boolean visible) Visits an annotation on a local variable type.void
visitLookupSwitchInsn
(Label dflt, int[] keys, Label[] labels) Visits a LOOKUPSWITCH instruction.void
visitMaxs
(int maxStack, int maxLocals) Visits the maximum stack size and the maximum number of local variables of the method.void
visitMethodInsn
(int opcode, String owner, String name, String descriptor, boolean isInterface) Visits a method instruction.void
visitMultiANewArrayInsn
(String descriptor, int numDimensions) Visits a MULTIANEWARRAY instruction.void
visitParameter
(String name, int access) Visits a parameter of this method.visitParameterAnnotation
(int parameter, String annotationDescriptor, boolean visible) Visits an annotation of a parameter this method.private void
visitSwitchInsn
(Label dflt, Label[] labels) void
visitTableSwitchInsn
(int min, int max, Label dflt, Label... labels) Visits a TABLESWITCH instruction.visitTryCatchAnnotation
(int typeRef, TypePath typePath, String descriptor, boolean visible) Visits an annotation on an exception handler type.void
visitTryCatchBlock
(Label start, Label end, Label handler, String type) Visits a try catch block.visitTypeAnnotation
(int typeRef, TypePath typePath, String descriptor, boolean visible) Visits an annotation on a type in the method signature.void
visitTypeInsn
(int opcode, String type) Visits a type instruction.void
visitVarInsn
(int opcode, int varIndex) Visits a local variable instruction.Methods inherited from class org.objectweb.asm.MethodVisitor
getDelegate, visitMethodInsn
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Field Details
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COMPUTE_NOTHING
static final int COMPUTE_NOTHINGIndicates that nothing must be computed.- See Also:
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COMPUTE_MAX_STACK_AND_LOCAL
static final int COMPUTE_MAX_STACK_AND_LOCALIndicates that the maximum stack size and the maximum number of local variables must be computed, from scratch.- See Also:
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COMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMES
static final int COMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMESIndicates that the maximum stack size and the maximum number of local variables must be computed, from the existing stack map frames. This can be done more efficiently than with the control flow graph algorithm used forCOMPUTE_MAX_STACK_AND_LOCAL
, by using a linear scan of the bytecode instructions.- See Also:
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COMPUTE_INSERTED_FRAMES
static final int COMPUTE_INSERTED_FRAMESIndicates that the stack map frames of type F_INSERT must be computed. The other frames are not computed. They should all be of type F_NEW and should be sufficient to compute the content of the F_INSERT frames, together with the bytecode instructions between a F_NEW and a F_INSERT frame - and without any knowledge of the type hierarchy (by definition of F_INSERT).- See Also:
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COMPUTE_ALL_FRAMES
static final int COMPUTE_ALL_FRAMESIndicates that all the stack map frames must be computed. In this case the maximum stack size and the maximum number of local variables is also computed.- See Also:
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NA
private static final int NAIndicates thatSTACK_SIZE_DELTA
is not applicable (not constant or never used).- See Also:
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STACK_SIZE_DELTA
private static final int[] STACK_SIZE_DELTAThe stack size variation corresponding to each JVM opcode. The stack size variation for opcode 'o' is given by the array element at index 'o'.- See Also:
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symbolTable
Where the constants used in this MethodWriter must be stored. -
accessFlags
private final int accessFlagsThe access_flags field of the method_info JVMS structure. This field can contain ASM specific access flags, such asOpcodes.ACC_DEPRECATED
, which are removed when generating the ClassFile structure. -
nameIndex
private final int nameIndexThe name_index field of the method_info JVMS structure. -
name
The name of this method. -
descriptorIndex
private final int descriptorIndexThe descriptor_index field of the method_info JVMS structure. -
descriptor
The descriptor of this method. -
maxStack
private int maxStackThe max_stack field of the Code attribute. -
maxLocals
private int maxLocalsThe max_locals field of the Code attribute. -
code
The 'code' field of the Code attribute. -
firstHandler
The first element in the exception handler list (used to generate the exception_table of the Code attribute). The next ones can be accessed with theHandler.nextHandler
field. May be null. -
lastHandler
The last element in the exception handler list (used to generate the exception_table of the Code attribute). The next ones can be accessed with theHandler.nextHandler
field. May be null. -
lineNumberTableLength
private int lineNumberTableLengthThe line_number_table_length field of the LineNumberTable code attribute. -
lineNumberTable
The line_number_table array of the LineNumberTable code attribute, or null. -
localVariableTableLength
private int localVariableTableLengthThe local_variable_table_length field of the LocalVariableTable code attribute. -
localVariableTable
The local_variable_table array of the LocalVariableTable code attribute, or null. -
localVariableTypeTableLength
private int localVariableTypeTableLengthThe local_variable_type_table_length field of the LocalVariableTypeTable code attribute. -
localVariableTypeTable
The local_variable_type_table array of the LocalVariableTypeTable code attribute, or null. -
stackMapTableNumberOfEntries
private int stackMapTableNumberOfEntriesThe number_of_entries field of the StackMapTable code attribute. -
stackMapTableEntries
The 'entries' array of the StackMapTable code attribute. -
lastCodeRuntimeVisibleTypeAnnotation
The last runtime visible type annotation of the Code attribute. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
lastCodeRuntimeInvisibleTypeAnnotation
The last runtime invisible type annotation of the Code attribute. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
firstCodeAttribute
The first non standard attribute of the Code attribute. The next ones can be accessed with theAttribute.nextAttribute
field. May be null.WARNING: this list stores the attributes in the reverse order of their visit. firstAttribute is actually the last attribute visited in
visitAttribute(org.objectweb.asm.Attribute)
. TheputMethodInfo(org.objectweb.asm.ByteVector)
method writes the attributes in the order defined by this list, i.e. in the reverse order specified by the user. -
numberOfExceptions
private final int numberOfExceptionsThe number_of_exceptions field of the Exceptions attribute. -
exceptionIndexTable
private final int[] exceptionIndexTableThe exception_index_table array of the Exceptions attribute, or null. -
signatureIndex
private final int signatureIndexThe signature_index field of the Signature attribute. -
lastRuntimeVisibleAnnotation
The last runtime visible annotation of this method. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
lastRuntimeInvisibleAnnotation
The last runtime invisible annotation of this method. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
visibleAnnotableParameterCount
private int visibleAnnotableParameterCountThe number of method parameters that can have runtime visible annotations, or 0. -
lastRuntimeVisibleParameterAnnotations
The runtime visible parameter annotations of this method. Each array element contains the last annotation of a parameter (which can be null - the previous ones can be accessed with theAnnotationWriter.previousAnnotation
field). May be null. -
invisibleAnnotableParameterCount
private int invisibleAnnotableParameterCountThe number of method parameters that can have runtime visible annotations, or 0. -
lastRuntimeInvisibleParameterAnnotations
The runtime invisible parameter annotations of this method. Each array element contains the last annotation of a parameter (which can be null - the previous ones can be accessed with theAnnotationWriter.previousAnnotation
field). May be null. -
lastRuntimeVisibleTypeAnnotation
The last runtime visible type annotation of this method. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
lastRuntimeInvisibleTypeAnnotation
The last runtime invisible type annotation of this method. The previous ones can be accessed with theAnnotationWriter.previousAnnotation
field. May be null. -
defaultValue
The default_value field of the AnnotationDefault attribute, or null. -
parametersCount
private int parametersCountThe parameters_count field of the MethodParameters attribute. -
parameters
The 'parameters' array of the MethodParameters attribute, or null. -
firstAttribute
The first non standard attribute of this method. The next ones can be accessed with theAttribute.nextAttribute
field. May be null.WARNING: this list stores the attributes in the reverse order of their visit. firstAttribute is actually the last attribute visited in
visitAttribute(org.objectweb.asm.Attribute)
. TheputMethodInfo(org.objectweb.asm.ByteVector)
method writes the attributes in the order defined by this list, i.e. in the reverse order specified by the user. -
compute
private final int computeIndicates what must be computed. Must be one ofCOMPUTE_ALL_FRAMES
,COMPUTE_INSERTED_FRAMES
,COMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMES
,COMPUTE_MAX_STACK_AND_LOCAL
orCOMPUTE_NOTHING
. -
firstBasicBlock
The first basic block of the method. The next ones (in bytecode offset order) can be accessed with theLabel.nextBasicBlock
field. -
lastBasicBlock
The last basic block of the method (in bytecode offset order). This field is updated each time a basic block is encountered, and is used to append it at the end of the basic block list. -
currentBasicBlock
The current basic block, i.e. the basic block of the last visited instruction. Whencompute
is equal toCOMPUTE_MAX_STACK_AND_LOCAL
orCOMPUTE_ALL_FRAMES
, this field is null for unreachable code. Whencompute
is equal toCOMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMES
orCOMPUTE_INSERTED_FRAMES
, this field stays unchanged throughout the whole method (i.e. the whole code is seen as a single basic block; indeed, the existing frames are sufficient by hypothesis to compute any intermediate frame - and the maximum stack size as well - without using any control flow graph). -
relativeStackSize
private int relativeStackSizeThe relative stack size after the last visited instruction. This size is relative to the beginning ofcurrentBasicBlock
, i.e. the true stack size after the last visited instruction is equal to theLabel.inputStackSize
of the current basic block plusrelativeStackSize
. Whencompute
is equal toCOMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMES
,currentBasicBlock
is always the start of the method, so this relative size is also equal to the absolute stack size after the last visited instruction. -
maxRelativeStackSize
private int maxRelativeStackSizeThe maximum relative stack size after the last visited instruction. This size is relative to the beginning ofcurrentBasicBlock
, i.e. the true maximum stack size after the last visited instruction is equal to theLabel.inputStackSize
of the current basic block plusmaxRelativeStackSize
.Whencompute
is equal toCOMPUTE_MAX_STACK_AND_LOCAL_FROM_FRAMES
,currentBasicBlock
is always the start of the method, so this relative size is also equal to the absolute maximum stack size after the last visited instruction. -
currentLocals
private int currentLocalsThe number of local variables in the last visited stack map frame. -
previousFrameOffset
private int previousFrameOffsetThe bytecode offset of the last frame that was written instackMapTableEntries
. -
previousFrame
private int[] previousFrameThe last frame that was written instackMapTableEntries
. This field has the same format ascurrentFrame
. -
currentFrame
private int[] currentFrameThe current stack map frame. The first element contains the bytecode offset of the instruction to which the frame corresponds, the second element is the number of locals and the third one is the number of stack elements. The local variables start at index 3 and are followed by the operand stack elements. In summary frame[0] = offset, frame[1] = numLocal, frame[2] = numStack. Local variables and operand stack entries contain abstract types, as defined inFrame
, but restricted toFrame.CONSTANT_KIND
,Frame.REFERENCE_KIND
orFrame.UNINITIALIZED_KIND
abstract types. Long and double types use only one array entry. -
hasSubroutines
private boolean hasSubroutinesWhether this method contains subroutines. -
hasAsmInstructions
private boolean hasAsmInstructionsWhether the bytecode of this method contains ASM specific instructions. -
lastBytecodeOffset
private int lastBytecodeOffsetThe start offset of the last visited instruction. Used to set the offset field of type annotations of type 'offset_target' (see JVMS 4.7.20.1). -
sourceOffset
private int sourceOffsetThe offset in bytes inSymbolTable.getSource()
from which the method_info for this method (excluding its first 6 bytes) must be copied, or 0. -
sourceLength
private int sourceLengthThe length in bytes inSymbolTable.getSource()
which must be copied to get the method_info for this method (excluding its first 6 bytes for access_flags, name_index and descriptor_index).
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Constructor Details
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MethodWriter
MethodWriter(SymbolTable symbolTable, int access, String name, String descriptor, String signature, String[] exceptions, int compute) Constructs a newMethodWriter
.- Parameters:
symbolTable
- where the constants used in this AnnotationWriter must be stored.access
- the method's access flags (seeOpcodes
).name
- the method's name.descriptor
- the method's descriptor (seeType
).signature
- the method's signature. May be null.exceptions
- the internal names of the method's exceptions. May be null.compute
- indicates what must be computed (see #compute).
-
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Method Details
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hasFrames
boolean hasFrames() -
hasAsmInstructions
boolean hasAsmInstructions() -
visitParameter
Description copied from class:MethodVisitor
Visits a parameter of this method.- Overrides:
visitParameter
in classMethodVisitor
- Parameters:
name
- parameter name or null if none is provided.access
- the parameter's access flags, onlyACC_FINAL
,ACC_SYNTHETIC
or/andACC_MANDATED
are allowed (seeOpcodes
).
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visitAnnotationDefault
Description copied from class:MethodVisitor
Visits the default value of this annotation interface method.- Overrides:
visitAnnotationDefault
in classMethodVisitor
- 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, exactly one visit method must be called on this annotation visitor, followed by visitEnd.
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visitAnnotation
Description copied from class:MethodVisitor
Visits an annotation of this method.- Overrides:
visitAnnotation
in classMethodVisitor
- Parameters:
descriptor
- 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.
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visitTypeAnnotation
public AnnotationVisitor visitTypeAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible) Description copied from class:MethodVisitor
Visits an annotation on a type in the method signature.- Overrides:
visitTypeAnnotation
in classMethodVisitor
- Parameters:
typeRef
- a reference to the annotated type. The sort of this type reference must beTypeReference.METHOD_TYPE_PARAMETER
,TypeReference.METHOD_TYPE_PARAMETER_BOUND
,TypeReference.METHOD_RETURN
,TypeReference.METHOD_RECEIVER
,TypeReference.METHOD_FORMAL_PARAMETER
orTypeReference.THROWS
. SeeTypeReference
.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.descriptor
- 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.
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visitAnnotableParameterCount
public void visitAnnotableParameterCount(int parameterCount, boolean visible) Description copied from class:MethodVisitor
Visits the number of method parameters that can have annotations. By default (i.e. when this method is not called), all the method parameters defined by the method descriptor can have annotations.- Overrides:
visitAnnotableParameterCount
in classMethodVisitor
- Parameters:
parameterCount
- the number of method parameters than can have annotations. This number must be less or equal than the number of parameter types in the method descriptor. It can be strictly less when a method has synthetic parameters and when these parameters are ignored when computing parameter indices for the purpose of parameter annotations (see https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.18).visible
- true to define the number of method parameters that can have annotations visible at runtime, false to define the number of method parameters that can have annotations invisible at runtime.
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visitParameterAnnotation
public AnnotationVisitor visitParameterAnnotation(int parameter, String annotationDescriptor, boolean visible) Description copied from class:MethodVisitor
Visits an annotation of a parameter this method.- Overrides:
visitParameterAnnotation
in classMethodVisitor
- Parameters:
parameter
- the parameter index. This index must be strictly smaller than the number of parameters in the method descriptor, and strictly smaller than the parameter count specified inMethodVisitor.visitAnnotableParameterCount(int, boolean)
. Important note: a parameter index i is not required to correspond to the i'th parameter descriptor in the method descriptor, in particular in case of synthetic parameters (see https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.18).annotationDescriptor
- 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.
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visitAttribute
Description copied from class:MethodVisitor
Visits a non standard attribute of this method.- Overrides:
visitAttribute
in classMethodVisitor
- Parameters:
attribute
- an attribute.
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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 classMethodVisitor
-
visitFrame
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 toOpcodes.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 (numStack
is 1 andstack[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 (numLocal
is 1, 2 or 3 andlocal
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 (numLocal
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 classMethodVisitor
- Parameters:
type
- the type of this stack map frame. Must beOpcodes.F_NEW
for expanded frames, orOpcodes.F_FULL
,Opcodes.F_APPEND
,Opcodes.F_CHOP
,Opcodes.F_SAME
orOpcodes.F_APPEND
,Opcodes.F_SAME1
for compressed frames.numLocal
- the number of local variables in the visited frame. Long and double values count for one variable.local
- the local variable types in this frame. This array must not be modified. Primitive types are represented byOpcodes.TOP
,Opcodes.INTEGER
,Opcodes.FLOAT
,Opcodes.LONG
,Opcodes.DOUBLE
,Opcodes.NULL
orOpcodes.UNINITIALIZED_THIS
(long and double are represented by a single element). Reference types are represented by String objects (representing internal names, seeType.getInternalName()
), and uninitialized types by Label objects (this label designates the NEW instruction that created this uninitialized value).numStack
- the number of operand stack elements in the visited frame. Long and double values count for one stack element.stack
- the operand stack types in this frame. This array must not be modified. Its content has the same format as the "local" array.
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visitInsn
public void visitInsn(int opcode) Description copied from class:MethodVisitor
Visits a zero operand instruction.- Overrides:
visitInsn
in classMethodVisitor
- 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.
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visitIntInsn
public void visitIntInsn(int opcode, int operand) Description copied from class:MethodVisitor
Visits an instruction with a single int operand.- Overrides:
visitIntInsn
in classMethodVisitor
- Parameters:
opcode
- the opcode of the instruction to be visited. This opcode is either BIPUSH, SIPUSH or NEWARRAY.operand
- the operand of the instruction to be visited.
When opcode is BIPUSH, operand value should be between Byte.MIN_VALUE and Byte.MAX_VALUE.
When opcode is SIPUSH, operand value should be between Short.MIN_VALUE and Short.MAX_VALUE.
When opcode is NEWARRAY, operand value should be one ofOpcodes.T_BOOLEAN
,Opcodes.T_CHAR
,Opcodes.T_FLOAT
,Opcodes.T_DOUBLE
,Opcodes.T_BYTE
,Opcodes.T_SHORT
,Opcodes.T_INT
orOpcodes.T_LONG
.
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visitVarInsn
public void visitVarInsn(int opcode, int varIndex) 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 classMethodVisitor
- 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.varIndex
- the operand of the instruction to be visited. This operand is the index of a local variable.
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visitTypeInsn
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 (seeType.getInternalName()
).- Overrides:
visitTypeInsn
in classMethodVisitor
- 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 (seeType.getInternalName()
).
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visitFieldInsn
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 classMethodVisitor
- 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 (seeType.getInternalName()
).name
- the field's name.descriptor
- the field's descriptor (seeType
).
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visitMethodInsn
public void visitMethodInsn(int opcode, String owner, String name, String descriptor, boolean isInterface) Description copied from class:MethodVisitor
Visits a method instruction. A method instruction is an instruction that invokes a method.- Overrides:
visitMethodInsn
in classMethodVisitor
- 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 (seeType.getInternalName()
).name
- the method's name.descriptor
- the method's descriptor (seeType
).isInterface
- if the method's owner class is an interface.
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visitInvokeDynamicInsn
public void visitInvokeDynamicInsn(String name, String descriptor, Handle bootstrapMethodHandle, Object... bootstrapMethodArguments) Description copied from class:MethodVisitor
Visits an invokedynamic instruction.- Overrides:
visitInvokeDynamicInsn
in classMethodVisitor
- Parameters:
name
- the method's name.descriptor
- the method's descriptor (seeType
).bootstrapMethodHandle
- the bootstrap method.bootstrapMethodArguments
- the bootstrap method constant arguments. Each argument must be anInteger
,Float
,Long
,Double
,String
,Type
,Handle
orConstantDynamic
value. This method is allowed to modify the content of the array so a caller should expect that this array may change.
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visitJumpInsn
Description copied from class:MethodVisitor
Visits a jump instruction. A jump instruction is an instruction that may jump to another instruction.- Overrides:
visitJumpInsn
in classMethodVisitor
- 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.
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visitLabel
Description copied from class:MethodVisitor
Visits a label. A label designates the instruction that will be visited just after it.- Overrides:
visitLabel
in classMethodVisitor
- Parameters:
label
- aLabel
object.
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visitLdcInsn
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 if (cst instanceof ConstantDynamic) { // ... } else { // throw an exception }
- Overrides:
visitLdcInsn
in classMethodVisitor
- Parameters:
value
- the constant to be loaded on the stack. This parameter must be a non nullInteger
, aFloat
, aLong
, aDouble
, aString
, aType
of OBJECT or ARRAY sort for.class
constants, for classes whose version is 49, aType
of METHOD sort for MethodType, aHandle
for MethodHandle constants, for classes whose version is 51 or aConstantDynamic
for a constant dynamic for classes whose version is 55.
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visitIincInsn
public void visitIincInsn(int varIndex, int increment) Description copied from class:MethodVisitor
Visits an IINC instruction.- Overrides:
visitIincInsn
in classMethodVisitor
- Parameters:
varIndex
- index of the local variable to be incremented.increment
- amount to increment the local variable by.
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visitTableSwitchInsn
Description copied from class:MethodVisitor
Visits a TABLESWITCH instruction.- Overrides:
visitTableSwitchInsn
in classMethodVisitor
- 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 themin + i
key.
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visitLookupSwitchInsn
Description copied from class:MethodVisitor
Visits a LOOKUPSWITCH instruction.- Overrides:
visitLookupSwitchInsn
in classMethodVisitor
- 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 thekeys[i]
key.
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visitSwitchInsn
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visitMultiANewArrayInsn
Description copied from class:MethodVisitor
Visits a MULTIANEWARRAY instruction.- Overrides:
visitMultiANewArrayInsn
in classMethodVisitor
- Parameters:
descriptor
- an array type descriptor (seeType
).numDimensions
- the number of dimensions of the array to allocate.
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visitInsnAnnotation
public AnnotationVisitor visitInsnAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible) Description copied from class:MethodVisitor
Visits an annotation on an instruction. This method must be called just after the annotated instruction. It can be called several times for the same instruction.- Overrides:
visitInsnAnnotation
in classMethodVisitor
- Parameters:
typeRef
- a reference to the annotated type. The sort of this type reference must beTypeReference.INSTANCEOF
,TypeReference.NEW
,TypeReference.CONSTRUCTOR_REFERENCE
,TypeReference.METHOD_REFERENCE
,TypeReference.CAST
,TypeReference.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT
,TypeReference.METHOD_INVOCATION_TYPE_ARGUMENT
,TypeReference.CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT
, orTypeReference.METHOD_REFERENCE_TYPE_ARGUMENT
. SeeTypeReference
.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.descriptor
- 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.
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visitTryCatchBlock
Description copied from class:MethodVisitor
Visits a try catch block.- Overrides:
visitTryCatchBlock
in classMethodVisitor
- Parameters:
start
- the beginning of the exception handler's scope (inclusive).end
- the end of the exception handler's scope (exclusive).handler
- the beginning of the exception handler's code.type
- the internal name of the type of exceptions handled by the handler (seeType.getInternalName()
), or null to catch any exceptions (for "finally" blocks).
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visitTryCatchAnnotation
public AnnotationVisitor visitTryCatchAnnotation(int typeRef, TypePath typePath, String descriptor, boolean visible) Description copied from class:MethodVisitor
Visits an annotation on an exception handler type. This method must be called after theMethodVisitor.visitTryCatchBlock(org.objectweb.asm.Label, org.objectweb.asm.Label, org.objectweb.asm.Label, java.lang.String)
for the annotated exception handler. It can be called several times for the same exception handler.- Overrides:
visitTryCatchAnnotation
in classMethodVisitor
- Parameters:
typeRef
- a reference to the annotated type. The sort of this type reference must beTypeReference.EXCEPTION_PARAMETER
. SeeTypeReference
.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.descriptor
- 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.
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visitLocalVariable
public void visitLocalVariable(String name, String descriptor, String signature, Label start, Label end, int index) Description copied from class:MethodVisitor
Visits a local variable declaration.- Overrides:
visitLocalVariable
in classMethodVisitor
- Parameters:
name
- the name of a local variable.descriptor
- 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.
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visitLocalVariableAnnotation
public AnnotationVisitor visitLocalVariableAnnotation(int typeRef, TypePath typePath, Label[] start, Label[] end, int[] index, String descriptor, boolean visible) Description copied from class:MethodVisitor
Visits an annotation on a local variable type.- Overrides:
visitLocalVariableAnnotation
in classMethodVisitor
- Parameters:
typeRef
- a reference to the annotated type. The sort of this type reference must beTypeReference.LOCAL_VARIABLE
orTypeReference.RESOURCE_VARIABLE
. SeeTypeReference
.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.descriptor
- 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.
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visitLineNumber
Description copied from class:MethodVisitor
Visits a line number declaration.- Overrides:
visitLineNumber
in classMethodVisitor
- 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.
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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 classMethodVisitor
- Parameters:
maxStack
- maximum stack size of the method.maxLocals
- maximum number of local variables for the method.
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computeAllFrames
private void computeAllFrames()Computes all the stack map frames of the method, from scratch. -
computeMaxStackAndLocal
private void computeMaxStackAndLocal()Computes the maximum stack size of 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 classMethodVisitor
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addSuccessorToCurrentBasicBlock
Adds a successor tocurrentBasicBlock
in the control flow graph.- Parameters:
info
- information about the control flow edge to be added.successor
- the successor block to be added to the current basic block.
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endCurrentBasicBlockWithNoSuccessor
private void endCurrentBasicBlockWithNoSuccessor()Ends the current basic block. This method must be used in the case where the current basic block does not have any successor.WARNING: this method must be called after the currently visited instruction has been put in
code
(if frames are computed, this method inserts a new Label to start a new basic block after the current instruction). -
visitFrameStart
int visitFrameStart(int offset, int numLocal, int numStack) Starts the visit of a new stack map frame, stored incurrentFrame
.- Parameters:
offset
- the bytecode offset of the instruction to which the frame corresponds.numLocal
- the number of local variables in the frame.numStack
- the number of stack elements in the frame.- Returns:
- the index of the next element to be written in this frame.
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visitAbstractType
void visitAbstractType(int frameIndex, int abstractType) Sets an abstract type incurrentFrame
.- Parameters:
frameIndex
- the index of the element to be set incurrentFrame
.abstractType
- an abstract type.
-
visitFrameEnd
void visitFrameEnd()Ends the visit ofcurrentFrame
by writing it in the StackMapTable entries and by updating the StackMapTable number_of_entries (except if the current frame is the first one, which is implicit in StackMapTable). Then resetscurrentFrame
to null. -
putFrame
private void putFrame()Compresses and writescurrentFrame
in a new StackMapTable entry. -
putAbstractTypes
private void putAbstractTypes(int start, int end) Puts some abstract types ofcurrentFrame
instackMapTableEntries
, using the JVMS verification_type_info format used in StackMapTable attributes.- Parameters:
start
- index of the first type incurrentFrame
to write.end
- index of last type incurrentFrame
to write (exclusive).
-
putFrameType
Puts the given public API frame element type instackMapTableEntries
, using the JVMS verification_type_info format used in StackMapTable attributes.- Parameters:
type
- a frame element type described using the same format as inMethodVisitor.visitFrame(int, int, java.lang.Object[], int, java.lang.Object[])
, i.e. eitherOpcodes.TOP
,Opcodes.INTEGER
,Opcodes.FLOAT
,Opcodes.LONG
,Opcodes.DOUBLE
,Opcodes.NULL
, orOpcodes.UNINITIALIZED_THIS
, or the internal name of a class, or a Label designating a NEW instruction (for uninitialized types).
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canCopyMethodAttributes
boolean canCopyMethodAttributes(ClassReader source, boolean hasSyntheticAttribute, boolean hasDeprecatedAttribute, int descriptorIndex, int signatureIndex, int exceptionsOffset) Returns whether the attributes of this method can be copied from the attributes of the given method (assuming there is no method visitor between the given ClassReader and this MethodWriter). This method should only be called just after this MethodWriter has been created, and before any content is visited. It returns true if the attributes corresponding to the constructor arguments (at most a Signature, an Exception, a Deprecated and a Synthetic attribute) are the same as the corresponding attributes in the given method.- Parameters:
source
- the source ClassReader from which the attributes of this method might be copied.hasSyntheticAttribute
- whether the method_info JVMS structure from which the attributes of this method might be copied contains a Synthetic attribute.hasDeprecatedAttribute
- whether the method_info JVMS structure from which the attributes of this method might be copied contains a Deprecated attribute.descriptorIndex
- the descriptor_index field of the method_info JVMS structure from which the attributes of this method might be copied.signatureIndex
- the constant pool index contained in the Signature attribute of the method_info JVMS structure from which the attributes of this method might be copied, or 0.exceptionsOffset
- the offset in 'source.b' of the Exceptions attribute of the method_info JVMS structure from which the attributes of this method might be copied, or 0.- Returns:
- whether the attributes of this method can be copied from the attributes of the method_info JVMS structure in 'source.b', between 'methodInfoOffset' and 'methodInfoOffset' + 'methodInfoLength'.
-
setMethodAttributesSource
void setMethodAttributesSource(int methodInfoOffset, int methodInfoLength) Sets the source from which the attributes of this method will be copied.- Parameters:
methodInfoOffset
- the offset in 'symbolTable.getSource()' of the method_info JVMS structure from which the attributes of this method will be copied.methodInfoLength
- the length in 'symbolTable.getSource()' of the method_info JVMS structure from which the attributes of this method will be copied.
-
computeMethodInfoSize
int computeMethodInfoSize()Returns the size of the method_info JVMS structure generated by this MethodWriter. Also add the names of the attributes of this method in the constant pool.- Returns:
- the size in bytes of the method_info JVMS structure.
-
putMethodInfo
Puts the content of the method_info JVMS structure generated by this MethodWriter into the given ByteVector.- Parameters:
output
- where the method_info structure must be put.
-
collectAttributePrototypes
Collects the attributes of this method into the given set of attribute prototypes.- Parameters:
attributePrototypes
- a set of attribute prototypes.
-