at.dms.kjc
Class JNullLiteral

java.lang.Object
  |
  +--at.dms.util.Utils
        |
        +--at.dms.compiler.Phylum
              |
              +--at.dms.kjc.JPhylum
                    |
                    +--at.dms.kjc.JExpression
                          |
                          +--at.dms.kjc.JLiteral
                                |
                                +--at.dms.kjc.JNullLiteral
All Implemented Interfaces:
Constants, Constants

public class JNullLiteral
extends JLiteral

Representation of a 'null' object reference literal.


Fields inherited from class at.dms.kjc.JExpression
EMPTY
 
Fields inherited from class at.dms.util.Utils
DBG_LEVEL_HIGH, DBG_LEVEL_LOW, DBG_LEVEL_NO
 
Fields inherited from interface at.dms.kjc.Constants
CMP_VERSION, JAV_CLASS, JAV_CLONE, JAV_CLONEABLE, JAV_CONSTRUCTOR, JAV_ERROR, JAV_EXCEPTION, JAV_INIT, JAV_LENGTH, JAV_NAME_SEPARATOR, JAV_OBJECT, JAV_OUTER_THIS, JAV_RUNTIME, JAV_RUNTIME_EXCEPTION, JAV_STATIC_INIT, JAV_STRING, JAV_STRINGBUFFER, JAV_THIS, JAV_THROWABLE, OPE_BAND, OPE_BNOT, OPE_BOR, OPE_BSR, OPE_BXOR, OPE_EQ, OPE_GE, OPE_GT, OPE_LE, OPE_LNOT, OPE_LT, OPE_MINUS, OPE_NE, OPE_PERCENT, OPE_PLUS, OPE_POSTDEC, OPE_POSTINC, OPE_PREDEC, OPE_PREINC, OPE_SIMPLE, OPE_SL, OPE_SLASH, OPE_SR, OPE_STAR, TID_ARRAY, TID_BOOLEAN, TID_BYTE, TID_CHAR, TID_CLASS, TID_DOUBLE, TID_FLOAT, TID_INT, TID_LONG, TID_SHORT, TID_VOID
 
Fields inherited from interface at.dms.classfile.Constants
ACC_ABSTRACT, ACC_FINAL, ACC_INTERFACE, ACC_NATIVE, ACC_NBR_FLAGS, ACC_PRIVATE, ACC_PROTECTED, ACC_PUBLIC, ACC_STATIC, ACC_STRICT, ACC_SUPER, ACC_SYNCHRONIZED, ACC_TRANSIENT, ACC_VOLATILE, ATT_CODE, ATT_CONSTANTVALUE, ATT_DEPRECATED, ATT_EXCEPTIONS, ATT_GENERIC, ATT_INNERCLASSES, ATT_LINENUMBERTABLE, ATT_LOCALVARIABLETABLE, ATT_SOURCEFILE, ATT_SYNTHETIC, CST_CLASS, CST_DOUBLE, CST_FIELD, CST_FLOAT, CST_INTEGER, CST_INTERFACEMETHOD, CST_LONG, CST_METHOD, CST_NAMEANDTYPE, CST_STRING, CST_UTF8, ENV_DEBUG_MODE, ENV_USE_CACHE, JAVA_MAGIC, JAVA_MAJOR, JAVA_MINOR, MAX_CODE_PER_METHOD, opc_aaload, opc_aastore, opc_aconst_null, opc_aload, opc_aload_0, opc_aload_1, opc_aload_2, opc_aload_3, opc_anewarray, opc_areturn, opc_arraylength, opc_astore, opc_astore_0, opc_astore_1, opc_astore_2, opc_astore_3, opc_athrow, opc_baload, opc_bastore, opc_bipush, opc_caload, opc_castore, opc_checkcast, opc_d2f, opc_d2i, opc_d2l, opc_dadd, opc_daload, opc_dastore, opc_dcmpg, opc_dcmpl, opc_dconst_0, opc_dconst_1, opc_ddiv, opc_dload, opc_dload_0, opc_dload_1, opc_dload_2, opc_dload_3, opc_dmul, opc_dneg, opc_drem, opc_dreturn, opc_dstore, opc_dstore_0, opc_dstore_1, opc_dstore_2, opc_dstore_3, opc_dsub, opc_dup, opc_dup_x1, opc_dup_x2, opc_dup2, opc_dup2_x1, opc_dup2_x2, opc_f2d, opc_f2i, opc_f2l, opc_fadd, opc_faload, opc_fastore, opc_fcmpg, opc_fcmpl, opc_fconst_0, opc_fconst_1, opc_fconst_2, opc_fdiv, opc_fload, opc_fload_0, opc_fload_1, opc_fload_2, opc_fload_3, opc_fmul, opc_fneg, opc_frem, opc_freturn, opc_fstore, opc_fstore_0, opc_fstore_1, opc_fstore_2, opc_fstore_3, opc_fsub, opc_getfield, opc_getstatic, opc_goto, opc_goto_w, opc_i2b, opc_i2c, opc_i2d, opc_i2f, opc_i2l, opc_i2s, opc_iadd, opc_iaload, opc_iand, opc_iastore, opc_iconst_0, opc_iconst_1, opc_iconst_2, opc_iconst_3, opc_iconst_4, opc_iconst_5, opc_iconst_m1, opc_idiv, opc_if_acmpeq, opc_if_acmpne, opc_if_icmpeq, opc_if_icmpge, opc_if_icmpgt, opc_if_icmple, opc_if_icmplt, opc_if_icmpne, opc_ifeq, opc_ifge, opc_ifgt, opc_ifle, opc_iflt, opc_ifne, opc_ifnonnull, opc_ifnull, opc_iinc, opc_iload, opc_iload_0, opc_iload_1, opc_iload_2, opc_iload_3, opc_imul, opc_ineg, opc_instanceof, opc_invokeinterface, opc_invokespecial, opc_invokestatic, opc_invokevirtual, opc_ior, opc_irem, opc_ireturn, opc_ishl, opc_ishr, opc_istore, opc_istore_0, opc_istore_1, opc_istore_2, opc_istore_3, opc_isub, opc_iushr, opc_ixor, opc_jsr, opc_jsr_w, opc_l2d, opc_l2f, opc_l2i, opc_ladd, opc_laload, opc_land, opc_lastore, opc_lcmp, opc_lconst_0, opc_lconst_1, opc_ldc, opc_ldc_w, opc_ldc2_w, opc_ldiv, opc_lload, opc_lload_0, opc_lload_1, opc_lload_2, opc_lload_3, opc_lmul, opc_lneg, opc_lookupswitch, opc_lor, opc_lrem, opc_lreturn, opc_lshl, opc_lshr, opc_lstore, opc_lstore_0, opc_lstore_1, opc_lstore_2, opc_lstore_3, opc_lsub, opc_lushr, opc_lxor, opc_monitorenter, opc_monitorexit, opc_multianewarray, opc_new, opc_newarray, opc_nop, opc_pop, opc_pop2, opc_putfield, opc_putstatic, opc_ret, opc_return, opc_saload, opc_sastore, opc_sipush, opc_swap, opc_tableswitch, opc_wide, opc_xxxunusedxxx, POO_ASCII_CONSTANT, POO_CLASS_CONSTANT, POO_DOUBLE_CONSTANT, POO_FLOAT_CONSTANT, POO_INTEGER_CONSTANT, POO_LONG_CONSTANT, POO_NAT_CONSTANT, POO_REF_CONSTANT, POO_STRING_CONSTANT, TYP_ADDRESS, TYP_DOUBLE, TYP_FLOAT, TYP_INT, TYP_LONG, TYP_REFERENCE, TYP_VOID
 
Constructor Summary
JNullLiteral(TokenReference where)
          Construct a node in the parsing tree
 
Method Summary
 void accept(KjcVisitor p)
          Accepts the specified visitor.
 JExpression checkExpression(CExpressionContext context)
          Check expression and evaluate and alter context.
 void genCode(CodeSequence code)
          Generates a sequence of bytecodes.
 CType getType()
          Compute the type of this expression (called after parsing)
 java.lang.Object getValue()
          Returns null.
 boolean isDefault()
          Yes, the null literal is the default for its type as its the only possible instance of its type.
 
Methods inherited from class at.dms.kjc.JLiteral
createLiteral, getLiteral, isLiteral, isLValue
 
Methods inherited from class at.dms.kjc.JExpression
checkExpression, convertType, fail, genBranch, getBooleanLiteral, getNumberLiteral, getOrdinalLiteral, getRealLiteral, getStringLiteral, isAssignableTo, isConstant, isStatementExpression, isSubTypePossible, setConstant, unParenthesize
 
Methods inherited from class at.dms.kjc.JPhylum
check, check, check, check
 
Methods inherited from class at.dms.compiler.Phylum
getTokenReference, setTokenReference
 
Methods inherited from class at.dms.util.Utils
assert, assert, fail, fail, hasFlag, hasMoreThanOneFlag, hasOtherFlags, splitQualifiedName, splitQualifiedName, vectorToArray, vectorToIntArray
 
Methods inherited from class java.lang.Object
, clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

JNullLiteral

public JNullLiteral(TokenReference where)
Construct a node in the parsing tree
Parameters:
where - the line of this node in the source code
Method Detail

getType

public CType getType()
Compute the type of this expression (called after parsing)
Overrides:
getType in class JExpression
Returns:
the type of this expression

getValue

public java.lang.Object getValue()
Returns null.
Overrides:
getValue in class JLiteral

isDefault

public boolean isDefault()
Yes, the null literal is the default for its type as its the only possible instance of its type.
Overrides:
isDefault in class JLiteral

checkExpression

public JExpression checkExpression(CExpressionContext context)
Check expression and evaluate and alter context.
Overrides:
checkExpression in class JExpression
Parameters:
context - the context of the check.
Returns:
a pure java expression including promote node.

accept

public void accept(KjcVisitor p)
Accepts the specified visitor.
Overrides:
accept in class JExpression
Parameters:
p - the visitor

genCode

public void genCode(CodeSequence code)
Generates a sequence of bytecodes.
Overrides:
genCode in class JExpression
Parameters:
code - the code list