/***
* 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.objectweb.asm;
/**
* A visitor to visit a Java method. The methods of this class must be called in
* the following order: ( visitParameter )* [
* visitAnnotationDefault ] ( visitAnnotation |
* visitTypeAnnotation | visitAttribute )* [
* visitCode ( visitFrame | visitXInsn |
* visitLabel | visitInsnAnnotation |
* visitTryCatchBlock | visitTryCatchBlockAnnotation |
* visitLocalVariable | visitLocalVariableAnnotation |
* visitLineNumber )* visitMaxs ] visitEnd. In
* addition, the visitXInsn and visitLabel methods must
* be called in the sequential order of the bytecode instructions of the visited
* code, visitInsnAnnotation must be called after the annotated
* instruction, visitTryCatchBlock must be called before the
* labels passed as arguments have been visited,
* visitTryCatchBlockAnnotation must be called after the
* corresponding try catch block has been visited, and the
* visitLocalVariable, visitLocalVariableAnnotation and
* visitLineNumber methods must be called after the labels
* passed as arguments have been visited.
*
* @author Eric Bruneton
*/
public abstract class MethodVisitor {
/**
* The ASM API version implemented by this visitor. The value of this field
* must be one of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
*/
protected final int api;
/**
* The method visitor to which this visitor must delegate method calls. May
* be null.
*/
protected MethodVisitor mv;
/**
* Constructs a new {@link MethodVisitor}.
*
* @param api
* the ASM API version implemented by this visitor. Must be one
* of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
*/
public MethodVisitor(final int api) {
this(api, null);
}
/**
* Constructs a new {@link MethodVisitor}.
*
* @param api
* the ASM API version implemented by this visitor. Must be one
* of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
* @param mv
* the method visitor to which this visitor must delegate method
* calls. May be null.
*/
public MethodVisitor(final int api, final MethodVisitor mv) {
if (api != Opcodes.ASM4 && api != Opcodes.ASM5) {
throw new IllegalArgumentException();
}
this.api = api;
this.mv = mv;
}
// -------------------------------------------------------------------------
// Parameters, annotations and non standard attributes
// -------------------------------------------------------------------------
/**
* Visits a parameter of this method.
*
* @param name
* parameter name or null if none is provided.
* @param access
* the parameter's access flags, only ACC_FINAL,
* ACC_SYNTHETIC or/and ACC_MANDATED are
* allowed (see {@link Opcodes}).
*/
public void visitParameter(String name, int access) {
if (api < Opcodes.ASM5) {
throw new RuntimeException();
}
if (mv != null) {
mv.visitParameter(name, access);
}
}
/**
* Visits the default value of this annotation interface method.
*
* @return 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.
*/
public AnnotationVisitor visitAnnotationDefault() {
if (mv != null) {
return mv.visitAnnotationDefault();
}
return null;
}
/**
* Visits an annotation of this method.
*
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
if (mv != null) {
return mv.visitAnnotation(desc, visible);
}
return null;
}
/**
* Visits an annotation on a type in the method signature.
*
* @param typeRef
* a reference to the annotated type. The sort of this type
* reference must be {@link TypeReference#METHOD_TYPE_PARAMETER
* METHOD_TYPE_PARAMETER},
* {@link TypeReference#METHOD_TYPE_PARAMETER_BOUND
* METHOD_TYPE_PARAMETER_BOUND},
* {@link TypeReference#METHOD_RETURN METHOD_RETURN},
* {@link TypeReference#METHOD_RECEIVER METHOD_RECEIVER},
* {@link TypeReference#METHOD_FORMAL_PARAMETER
* METHOD_FORMAL_PARAMETER} or {@link TypeReference#THROWS
* THROWS}. See {@link TypeReference}.
* @param 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.
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitTypeAnnotation(int typeRef,
TypePath typePath, String desc, boolean visible) {
if (api < Opcodes.ASM5) {
throw new RuntimeException();
}
if (mv != null) {
return mv.visitTypeAnnotation(typeRef, typePath, desc, visible);
}
return null;
}
/**
* Visits an annotation of a parameter this method.
*
* @param parameter
* the parameter index.
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitParameterAnnotation(int parameter,
String desc, boolean visible) {
if (mv != null) {
return mv.visitParameterAnnotation(parameter, desc, visible);
}
return null;
}
/**
* Visits a non standard attribute of this method.
*
* @param attr
* an attribute.
*/
public void visitAttribute(Attribute attr) {
if (mv != null) {
mv.visitAttribute(attr);
}
}
/**
* Starts the visit of the method's code, if any (i.e. non abstract method).
*/
public void visitCode() {
if (mv != null) {
mv.visitCode();
}
}
/**
* 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 {@link Opcodes#V1_6 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):
*
nStack is 1 and stack[0] contains value for the
* type of the stack item).nLocal is 1, 2 or 3 and
* local elements contains values representing added types).nLocals is 1, 2 or 3).
* 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
* }
*
*
* @param cst
* the constant to be loaded on the stack. This parameter must be
* a non null {@link Integer}, a {@link Float}, a {@link Long}, a
* {@link Double}, a {@link String}, a {@link Type} of OBJECT or
* ARRAY sort for .class constants, for classes whose
* version is 49.0, a {@link Type} of METHOD sort or a
* {@link Handle} for MethodType and MethodHandle constants, for
* classes whose version is 51.0.
*/
public void visitLdcInsn(Object cst) {
if (mv != null) {
mv.visitLdcInsn(cst);
}
}
/**
* Visits an IINC instruction.
*
* @param var
* index of the local variable to be incremented.
* @param increment
* amount to increment the local variable by.
*/
public void visitIincInsn(int var, int increment) {
if (mv != null) {
mv.visitIincInsn(var, increment);
}
}
/**
* Visits a TABLESWITCH instruction.
*
* @param min
* the minimum key value.
* @param max
* the maximum key value.
* @param dflt
* beginning of the default handler block.
* @param labels
* beginnings of the handler blocks. labels[i] is the
* beginning of the handler block for the min + i key.
*/
public void visitTableSwitchInsn(int min, int max, Label dflt,
Label... labels) {
if (mv != null) {
mv.visitTableSwitchInsn(min, max, dflt, labels);
}
}
/**
* Visits a LOOKUPSWITCH instruction.
*
* @param dflt
* beginning of the default handler block.
* @param keys
* the values of the keys.
* @param labels
* beginnings of the handler blocks. labels[i] is the
* beginning of the handler block for the keys[i] key.
*/
public void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels) {
if (mv != null) {
mv.visitLookupSwitchInsn(dflt, keys, labels);
}
}
/**
* Visits a MULTIANEWARRAY instruction.
*
* @param desc
* an array type descriptor (see {@link Type Type}).
* @param dims
* number of dimensions of the array to allocate.
*/
public void visitMultiANewArrayInsn(String desc, int dims) {
if (mv != null) {
mv.visitMultiANewArrayInsn(desc, dims);
}
}
/**
* 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.
*
* @param typeRef
* a reference to the annotated type. The sort of this type
* reference must be {@link TypeReference#INSTANCEOF INSTANCEOF},
* {@link TypeReference#NEW NEW},
* {@link TypeReference#CONSTRUCTOR_REFERENCE
* CONSTRUCTOR_REFERENCE}, {@link TypeReference#METHOD_REFERENCE
* METHOD_REFERENCE}, {@link TypeReference#CAST CAST},
* {@link TypeReference#CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT
* CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT},
* {@link TypeReference#METHOD_INVOCATION_TYPE_ARGUMENT
* METHOD_INVOCATION_TYPE_ARGUMENT},
* {@link TypeReference#CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT
* CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT}, or
* {@link TypeReference#METHOD_REFERENCE_TYPE_ARGUMENT
* METHOD_REFERENCE_TYPE_ARGUMENT}. See {@link TypeReference}.
* @param 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.
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitInsnAnnotation(int typeRef,
TypePath typePath, String desc, boolean visible) {
if (api < Opcodes.ASM5) {
throw new RuntimeException();
}
if (mv != null) {
return mv.visitInsnAnnotation(typeRef, typePath, desc, visible);
}
return null;
}
// -------------------------------------------------------------------------
// Exceptions table entries, debug information, max stack and max locals
// -------------------------------------------------------------------------
/**
* Visits a try catch block.
*
* @param start
* beginning of the exception handler's scope (inclusive).
* @param end
* end of the exception handler's scope (exclusive).
* @param handler
* beginning of the exception handler's code.
* @param type
* internal name of the type of exceptions handled by the
* handler, or null to catch any exceptions (for
* "finally" blocks).
* @throws IllegalArgumentException
* if one of the labels has already been visited by this visitor
* (by the {@link #visitLabel visitLabel} method).
*/
public void visitTryCatchBlock(Label start, Label end, Label handler,
String type) {
if (mv != null) {
mv.visitTryCatchBlock(start, end, handler, type);
}
}
/**
* Visits an annotation on an exception handler type. This method must be
* called after the {@link #visitTryCatchBlock} for the annotated
* exception handler. It can be called several times for the same exception
* handler.
*
* @param typeRef
* a reference to the annotated type. The sort of this type
* reference must be {@link TypeReference#EXCEPTION_PARAMETER
* EXCEPTION_PARAMETER}. See {@link TypeReference}.
* @param 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.
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitTryCatchAnnotation(int typeRef,
TypePath typePath, String desc, boolean visible) {
if (api < Opcodes.ASM5) {
throw new RuntimeException();
}
if (mv != null) {
return mv.visitTryCatchAnnotation(typeRef, typePath, desc, visible);
}
return null;
}
/**
* Visits a local variable declaration.
*
* @param name
* the name of a local variable.
* @param desc
* the type descriptor of this local variable.
* @param signature
* the type signature of this local variable. May be
* null if the local variable type does not use generic
* types.
* @param start
* the first instruction corresponding to the scope of this local
* variable (inclusive).
* @param end
* the last instruction corresponding to the scope of this local
* variable (exclusive).
* @param index
* the local variable's index.
* @throws IllegalArgumentException
* if one of the labels has not already been visited by this
* visitor (by the {@link #visitLabel visitLabel} method).
*/
public void visitLocalVariable(String name, String desc, String signature,
Label start, Label end, int index) {
if (mv != null) {
mv.visitLocalVariable(name, desc, signature, start, end, index);
}
}
/**
* Visits an annotation on a local variable type.
*
* @param typeRef
* a reference to the annotated type. The sort of this type
* reference must be {@link TypeReference#LOCAL_VARIABLE
* LOCAL_VARIABLE} or {@link TypeReference#RESOURCE_VARIABLE
* RESOURCE_VARIABLE}. See {@link TypeReference}.
* @param 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.
* @param start
* the fist instructions corresponding to the continuous ranges
* that make the scope of this local variable (inclusive).
* @param 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.
* @param index
* the local variable's index in each range. This array must have
* the same size as the 'start' array.
* @param desc
* the class descriptor of the annotation class.
* @param visible
* true if the annotation is visible at runtime.
* @return a visitor to visit the annotation values, or null if
* this visitor is not interested in visiting this annotation.
*/
public AnnotationVisitor visitLocalVariableAnnotation(int typeRef,
TypePath typePath, Label[] start, Label[] end, int[] index,
String desc, boolean visible) {
if (api < Opcodes.ASM5) {
throw new RuntimeException();
}
if (mv != null) {
return mv.visitLocalVariableAnnotation(typeRef, typePath, start,
end, index, desc, visible);
}
return null;
}
/**
* Visits a line number declaration.
*
* @param line
* a line number. This number refers to the source file from
* which the class was compiled.
* @param start
* the first instruction corresponding to this line number.
* @throws IllegalArgumentException
* if start has not already been visited by this
* visitor (by the {@link #visitLabel visitLabel} method).
*/
public void visitLineNumber(int line, Label start) {
if (mv != null) {
mv.visitLineNumber(line, start);
}
}
/**
* Visits the maximum stack size and the maximum number of local variables
* of the method.
*
* @param maxStack
* maximum stack size of the method.
* @param maxLocals
* maximum number of local variables for the method.
*/
public void visitMaxs(int maxStack, int maxLocals) {
if (mv != null) {
mv.visitMaxs(maxStack, maxLocals);
}
}
/**
* 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.
*/
public void visitEnd() {
if (mv != null) {
mv.visitEnd();
}
}
}