Package com.ibm.wala.shrike.shrikeBT

Class Compiler

  • All Implemented Interfaces:
    Constants
    Direct Known Subclasses:
    CTCompiler
    public abstract class Compiler
extends java.lang.Object
implements Constants
    This class generates Java bytecode from ShrikeBT Instructions.

    If there are too many instructions to fit into 64K bytecodes, then we break the method up, generating auxiliary methods called by the main method.

    This class is abstract; there are subclasses for specific class file access toolkits. These toolkits are responsible for providing ways to allocate constant pool entries.

    • Constructor Detail

      • Compiler

        public Compiler​(boolean isConstructor,
                boolean isStatic,
                java.lang.String classType,
                java.lang.String signature,
                IInstruction[] instructions,
                ExceptionHandler[][] handlers,
                int[] instructionsToBytecodes)
        Initialize a Compiler for the given method data.
        Parameters:
        isStatic - true iff the method is static
        classType - the JVM type of the class the method belongs to
        signature - the JVM signature of the method
        instructions - the ShrikeBT instructions
        handlers - the ShrikeBT exception handlers
        instructionsToBytecodes - the map from instructions to original bytecode offsets
        Throws:
        java.lang.IllegalArgumentException - if handlers is null
        java.lang.IllegalArgumentException - if instructions is null
        java.lang.IllegalArgumentException - if instructionsToBytecodes is null

      • Compiler

        protected Compiler​(MethodData info)
        Extract the data for the method to be compiled from the MethodData container.

    • Method Detail

      • getClassType

        public final java.lang.String getClassType()
        Returns:
        the JVM type for the class this method belongs to

      • setPresetConstants

        public final void setPresetConstants​(ConstantPoolReader cp)
        Notify the compiler that the constants appearing in the ConstantPoolReader cp will appear in the final class file.

        Instructions which were extracted from a class file with the same ConstantPoolReader can be written back much more efficiently if the same constant pool indices are valid in the new class file.

      • allocateConstantPoolInteger

        protected abstract int allocateConstantPoolInteger​(int v)

      • allocateConstantPoolFloat

        protected abstract int allocateConstantPoolFloat​(float v)

      • allocateConstantPoolLong

        protected abstract int allocateConstantPoolLong​(long v)

      • allocateConstantPoolDouble

        protected abstract int allocateConstantPoolDouble​(double v)

      • allocateConstantPoolString

        protected abstract int allocateConstantPoolString​(java.lang.String v)

      • allocateConstantPoolClassType

        protected abstract int allocateConstantPoolClassType​(java.lang.String c)

      • allocateConstantPoolMethodType

        protected abstract int allocateConstantPoolMethodType​(java.lang.String c)

      • allocateConstantPoolField

        protected abstract int allocateConstantPoolField​(java.lang.String c,
                                                 java.lang.String name,
                                                 java.lang.String type)

      • allocateConstantPoolMethod

        protected abstract int allocateConstantPoolMethod​(java.lang.String c,
                                                  java.lang.String name,
                                                  java.lang.String sig)

      • allocateConstantPoolInterfaceMethod

        protected abstract int allocateConstantPoolInterfaceMethod​(java.lang.String c,
                                                           java.lang.String name,
                                                           java.lang.String sig)

      • createHelperMethod

        protected abstract java.lang.String createHelperMethod​(boolean isStatic,
                                                       java.lang.String sig)

      • compile

        public final void compile()
        Do the work of generating new bytecodes.

        In pathological cases this could throw an Error, when the code you passed in is too large to fit into a single JVM method and Compiler can't find a way to break it up into helper methods. You probably won't encounter this unless you try to make it happen :-).

      • getOutput

        public final Compiler.Output getOutput()
        Get the output bytecodes and other information for the method.

      • getAuxiliaryMethods

        public final Compiler.Output[] getAuxiliaryMethods()
        Get bytecodes and other information for any helper methods that are required to implement the main method. These helpers represent code that could not be fit into the main method because of JVM method size constraints.