Package com.saxonica.ee.bytecode.util

Class Generator

  • public class Generator
extends org.objectweb.asm.commons.GeneratorAdapter
    This class is an extension of the ASM-supplied GeneratorAdapter library, containing additional utility and shortcut methods for bytecode generation

    • Field Summary

      • Fields inherited from class org.objectweb.asm.commons.GeneratorAdapter

        ADD, AND, DIV, EQ, GE, GT, LE, LT, MUL, NE, NEG, OR, REM, SHL, SHR, SUB, USHR, XOR

      • Fields inherited from class org.objectweb.asm.commons.LocalVariablesSorter

        firstLocal, nextLocal

      • Fields inherited from class org.objectweb.asm.MethodVisitor

        api, mv

    • Constructor Summary

      Constructors 
      Constructor Description
      Generator​(int access, org.objectweb.asm.commons.Method method, boolean throwsXPathException, org.objectweb.asm.ClassVisitor cv)
      Create a code generator for a particular method

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addComment​(CompilerService compiler, java.lang.String message)
      Add a comment (in the form of an unused label) to the code listing
      void checkClass​(java.lang.Class theClass)
      Generate a "checking" cast instruction, given a Class to check against.
      void concatenateStrings​(int n)
      Generate code to concatenate a sequence of string objects.
      void getInstanceField​(java.lang.Class theClass, java.lang.String fieldName)
      Helper method to get an instance-level field of an object
      org.objectweb.asm.Type getLocalType​(int local)
      Returns the type of the given local variable.
      void getStaticField​(java.lang.Class theClass, java.lang.String fieldName, java.lang.Class fieldClass)
      Helper method to generate code that gets a static field
      void goTo​(LabelInfo labelInfo)
      Generate code to go to a LabelInfo
      void ifFalse​(LabelInfo label)
      Generate code to test whether the object on top of stack is NOT an instance of a given class
      void ifInstance​(java.lang.Class theClass, LabelInfo label)
      Generate code to test whether the object on top of stack is an instance of a given class
      void ifNotInstance​(java.lang.Class theClass, LabelInfo label)
      Generate code to test whether the object on top of stack is NOT an instance of a given class
      void ifNotSameObject​(LabelInfo label)
      Generate code to test whether the two object references on top of stack refer to different objects
      void ifSameObject​(LabelInfo label)
      Generate code to test whether the two object references on top of stack refer to the same object
      void ifTrue​(LabelInfo label)
      Generate code to test whether the object on top of stack is the boolean true
      void invokeConstructor​(java.lang.Class<?> theClass, java.lang.Class<?>... argTypes)
      Helper method to generate code that invokes a constructor.
      void invokeDefaultConstructor​(java.lang.Class<?> theClass)
      Helper method for a zero-argument constructor.
      void invokeInstanceMethod​(java.lang.Class<?> theClass, java.lang.String methodName, java.lang.Class... argTypes)
      Helper method to generate code that invokes an instance method
      void invokeStaticMethod​(java.lang.Class<?> theClass, java.lang.String methodName, java.lang.Class... argTypes)
      Helper method to generate code that invokes a static method
      void loadArgOrLocal​(int slot)
      Load a local variable or method argument
      void loadLocal​(int local)
      Generates the instruction to load the given local variable on the stack.
      void newInstance​(java.lang.Class theClass)
      Helper method to generate code that creates a new instance of a class
      int newLocal​(java.lang.Class<?> theClass)
      Helper method to generate a local bytecode variable
      void pushNull()
      Push "null" onto the stack
      void showIntVariable​(CompilerService compiler, java.lang.String name, int slot)
      Generate code to output the value of a run-time variable (which must hold an int)
      void showLongVariable​(CompilerService compiler, java.lang.String name, int slot)
      Generate code to output the value of a run-time variable (which must hold a long)
      void showMessage​(CompilerService compiler, java.lang.String message)
      Generate code to output a simple diagnostic message at run-time
      void showObject​(CompilerService compiler, java.lang.String label)
      Generate code to output the value of of the object on the top of the bytecode stack
      void showObjectVariable​(CompilerService compiler, java.lang.String name, int slot)
      Generate code to output the value of a run-time bytecode variable (which must hold an object)
      void storeArgOrLocal​(int slot)
      Generate code to store the value from top of stack into a local variable or method argument slot
      void storeLocal​(int local)
      Generates the instruction to store the top stack value in the given local variable.
      void visitTryCatchBlock​(LabelInfo start, LabelInfo end, LabelInfo handler, java.lang.String type)
      Process a try/catch block

      • Methods inherited from class org.objectweb.asm.commons.GeneratorAdapter

        arrayLength, arrayLoad, arrayStore, box, cast, catchException, checkCast, dup, dup2, dup2X1, dup2X2, dupX1, dupX2, endMethod, getField, getStatic, goTo, ifCmp, ifICmp, ifNonNull, ifNull, ifZCmp, iinc, instanceOf, invokeConstructor, invokeDynamic, invokeInterface, invokeStatic, invokeVirtual, loadArg, loadArgArray, loadArgs, loadArgs, loadLocal, loadThis, mark, mark, math, monitorEnter, monitorExit, newArray, newInstance, newLabel, not, pop, pop2, push, push, push, push, push, push, push, push, putField, putStatic, ret, returnValue, setLocalType, storeArg, storeLocal, swap, swap, tableSwitch, tableSwitch, throwException, throwException, unbox, valueOf

      • Methods inherited from class org.objectweb.asm.commons.LocalVariablesSorter

        newLocal, newLocalMapping, updateNewLocals, visitFrame, visitIincInsn, visitLocalVariable, visitLocalVariableAnnotation, visitMaxs, visitVarInsn

      • Methods inherited from class org.objectweb.asm.MethodVisitor

        visitAnnotation, visitAnnotationDefault, visitAttribute, visitCode, visitEnd, visitFieldInsn, visitInsn, visitInsnAnnotation, visitIntInsn, visitInvokeDynamicInsn, visitJumpInsn, visitLabel, visitLdcInsn, visitLineNumber, visitLookupSwitchInsn, visitMethodInsn, visitMethodInsn, visitMultiANewArrayInsn, visitParameter, visitParameterAnnotation, visitTableSwitchInsn, visitTryCatchAnnotation, visitTryCatchBlock, visitTypeAnnotation, visitTypeInsn

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Generator

        public Generator​(int access,
                 org.objectweb.asm.commons.Method method,
                 boolean throwsXPathException,
                 org.objectweb.asm.ClassVisitor cv)
        Create a code generator for a particular method
        Parameters:
        access - the visibility of the method, typically PUBLIC
        method - the Method object containing details of the argument and return types
        throwsXPathException - true if the method throws XPathException on error
        cv - the class visitor for the containing class

    • Method Detail

      • ifInstance

        public void ifInstance​(java.lang.Class theClass,
                       LabelInfo label)
        Generate code to test whether the object on top of stack is an instance of a given class
        Parameters:
        theClass - the class to be tested
        label - the label to jump to if the current object is an instance of the class. If it is not an instance, control passes to the next instruction

      • ifNotInstance

        public void ifNotInstance​(java.lang.Class theClass,
                          LabelInfo label)
        Generate code to test whether the object on top of stack is NOT an instance of a given class
        Parameters:
        theClass - the class to be tested
        label - the label to jump to if the current object is an instance of the class. If it is not an instance, control passes to the next instruction

      • goTo

        public void goTo​(LabelInfo labelInfo)
        Generate code to go to a LabelInfo
        Parameters:
        labelInfo - the label to jump to

      • pushNull

        public void pushNull()
        Push "null" onto the stack

      • ifTrue

        public void ifTrue​(LabelInfo label)
        Generate code to test whether the object on top of stack is the boolean true
        Parameters:
        label - the label to jump to if the value on top of stack is true (non-zero)

      • ifFalse

        public void ifFalse​(LabelInfo label)
        Generate code to test whether the object on top of stack is NOT an instance of a given class
        Parameters:
        label - the label to jump to if the current object is false (zero)

      • ifSameObject

        public void ifSameObject​(LabelInfo label)
        Generate code to test whether the two object references on top of stack refer to the same object
        Parameters:
        label - the label to jump to if the two object references are equal

      • ifNotSameObject

        public void ifNotSameObject​(LabelInfo label)
        Generate code to test whether the two object references on top of stack refer to different objects
        Parameters:
        label - the label to jump to if the two object references are different

      • checkClass

        public void checkClass​(java.lang.Class theClass)
        Generate a "checking" cast instruction, given a Class to check against.
        Parameters:
        theClass - the class to be tested

      • addComment

        public void addComment​(CompilerService compiler,
                       java.lang.String message)
        Add a comment (in the form of an unused label) to the code listing
        Parameters:
        compiler - the compiler service
        message - the comment to be added to the code

      • showMessage

        public void showMessage​(CompilerService compiler,
                        java.lang.String message)
        Generate code to output a simple diagnostic message at run-time
        Parameters:
        compiler - the compiler service
        message - the message to be output at run-time

      • showObject

        public void showObject​(CompilerService compiler,
                       java.lang.String label)
        Generate code to output the value of of the object on the top of the bytecode stack
        Parameters:
        compiler - the compiler service
        label - a label used to prefix the message to be output at run-time

      • showObjectVariable

        public void showObjectVariable​(CompilerService compiler,
                               java.lang.String name,
                               int slot)
        Generate code to output the value of a run-time bytecode variable (which must hold an object)
        Parameters:
        compiler - the compiler service
        name - a label used to prefix the message to be output at run-time, typically the variable name
        slot - the slot number on the bytecode stack whose value is to be displayed

      • showLongVariable

        public void showLongVariable​(CompilerService compiler,
                             java.lang.String name,
                             int slot)
        Generate code to output the value of a run-time variable (which must hold a long)
        Parameters:
        compiler - the compiler service
        name - a label used to prefix the message to be output at run-time, typically the variable name
        slot - the slot number on the bytecode stack whose value is to be displayed

      • showIntVariable

        public void showIntVariable​(CompilerService compiler,
                            java.lang.String name,
                            int slot)
        Generate code to output the value of a run-time variable (which must hold an int)
        Parameters:
        compiler - the compiler service
        name - a label used to prefix the message to be output at run-time, typically the variable name
        slot - the slot number on the bytecode stack whose value is to be displayed

      • getStaticField

        public void getStaticField​(java.lang.Class theClass,
                           java.lang.String fieldName,
                           java.lang.Class fieldClass)
        Helper method to generate code that gets a static field
        Parameters:
        theClass - the class on which the field is defined
        fieldName - the name of the field to be fetched
        fieldClass - the class of the field to be fetched

      • invokeStaticMethod

        public void invokeStaticMethod​(java.lang.Class<?> theClass,
                               java.lang.String methodName,
                               java.lang.Class... argTypes)
        Helper method to generate code that invokes a static method
        Parameters:
        theClass - the class on which the method is defined
        methodName - the name of the method to be invoked
        argTypes - the classes of the arguments to the method
        Throws:
        java.lang.AssertionError - if no suitable method is defined on this class

      • invokeInstanceMethod

        public void invokeInstanceMethod​(java.lang.Class<?> theClass,
                                 java.lang.String methodName,
                                 java.lang.Class... argTypes)
        Helper method to generate code that invokes an instance method
        Parameters:
        theClass - the instance class on which the method is defined
        methodName - the name of the method to be invoked
        argTypes - the classes of the arguments to the method
        Throws:
        java.lang.AssertionError - if no suitable method is defined on this interface

      • getInstanceField

        public void getInstanceField​(java.lang.Class theClass,
                             java.lang.String fieldName)
        Helper method to get an instance-level field of an object
        Parameters:
        theClass - the instance class on which the method is defined
        fieldName - the name of the field to be obtained
        Throws:
        java.lang.AssertionError - if no suitable method is defined on this interface

      • invokeDefaultConstructor

        public void invokeDefaultConstructor​(java.lang.Class<?> theClass)
        Helper method for a zero-argument constructor. Generates code to invoke the constructor, leaving the constructed instance on the top of the bytecode stack
        Parameters:
        theClass - the class of object to be constructed

      • newInstance

        public void newInstance​(java.lang.Class theClass)
        Helper method to generate code that creates a new instance of a class
        Parameters:
        theClass - the class to be instantiated

      • invokeConstructor

        public void invokeConstructor​(java.lang.Class<?> theClass,
                              java.lang.Class<?>... argTypes)
        Helper method to generate code that invokes a constructor. Precondition: the target of the method and all its arguments are on the stack (the target must first be created using the newInstance() instruction). Postcondition: the above items are removed from the stack
        Parameters:
        theClass - the class on which the method is defined
        argTypes - the classes of the arguments to the constructor
        Throws:
        java.lang.AssertionError - if no suitable constructor is defined on this class

      • newLocal

        public int newLocal​(java.lang.Class<?> theClass)
        Helper method to generate a local bytecode variable
        Parameters:
        theClass - the class of the variable
        Returns:
        the slot number allocated to the variable

      • loadLocal

        public void loadLocal​(int local)
        Generates the instruction to load the given local variable on the stack.
        Overrides:
        loadLocal in class org.objectweb.asm.commons.GeneratorAdapter
        Parameters:
        local - a local variable identifier, as returned by newLocal().

      • loadArgOrLocal

        public void loadArgOrLocal​(int slot)
        Load a local variable or method argument
        Parameters:
        slot - the slot number to be loaded, which may represent either a method argument or a local variable

      • storeLocal

        public void storeLocal​(int local)
        Generates the instruction to store the top stack value in the given local variable.
        Overrides:
        storeLocal in class org.objectweb.asm.commons.GeneratorAdapter
        Parameters:
        local - a local variable identifier, as returned by newLocal().

      • storeArgOrLocal

        public void storeArgOrLocal​(int slot)
        Generate code to store the value from top of stack into a local variable or method argument slot
        Parameters:
        slot - the slot number to be used, which may represent either a method argument or a local variable

      • getLocalType

        public org.objectweb.asm.Type getLocalType​(int local)
        Returns the type of the given local variable.
        Overrides:
        getLocalType in class org.objectweb.asm.commons.GeneratorAdapter
        Parameters:
        local - a local variable identifier, as returned by newLocal().
        Returns:
        the type of the given local variable.

      • visitTryCatchBlock

        public void visitTryCatchBlock​(LabelInfo start,
                               LabelInfo end,
                               LabelInfo handler,
                               java.lang.String type)
        Process a try/catch block
        Parameters:
        start - the label for the start of the try block
        end - the label for the end of the try block
        handler - the label for the catch block
        type - the type

      • concatenateStrings

        public void concatenateStrings​(int n)
        Generate code to concatenate a sequence of string objects. The strings must be on the stack, in order. On completion, the concatenated string is on the top of the bytecode stack
        Parameters:
        n - the number of strings to be concatenated